80_FR_9435 80 FR 9400 - Airworthiness Directives; the Boeing Company Airplanes

80 FR 9400 - Airworthiness Directives; the Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 35 (February 23, 2015)

Page Range9400-9414
FR Document2015-03540

We are revising an earlier proposed airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. The NPRM proposed to require modifying the fuel quantity indication system (FQIS) wiring or fuel tank systems to prevent development of an ignition source inside the center fuel tank. The NPRM was prompted by fuel system reviews conducted by the manufacturer. This action revises the NPRM by revising the applicability, including optional actions for cargo airplanes, and extending the compliance time. We are proposing this supplemental NPRM (SNPRM) to prevent ignition sources inside the center fuel tank, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane. Since these actions significantly change the corrective action options for cargo airplanes relative to the proposal in the NPRM, and because the cost estimate is significantly revised, we are reopening the comment period to allow the public the chance to comment on these proposed changes.

Federal Register, Volume 80 Issue 35 (Monday, February 23, 2015)
[Federal Register Volume 80, Number 35 (Monday, February 23, 2015)]
[Proposed Rules]
[Pages 9400-9414]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-03540]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0187; Directorate Identifier 2011-NM-094-AD]
RIN 2120-AA64


Airworthiness Directives; the Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: We are revising an earlier proposed airworthiness directive 
(AD) for certain The Boeing Company Model 757 airplanes. The NPRM 
proposed to require modifying the fuel quantity indication system 
(FQIS) wiring or fuel tank systems to prevent development of an 
ignition source inside the center fuel tank. The NPRM was prompted by 
fuel system reviews conducted by the manufacturer. This action revises 
the NPRM by revising the applicability, including optional actions for 
cargo airplanes, and extending the compliance time. We are proposing 
this supplemental NPRM (SNPRM) to prevent ignition sources inside the 
center fuel tank, which, in combination with flammable fuel vapors, 
could result in fuel tank explosions and consequent loss of the 
airplane. Since these actions significantly change the corrective 
action options for cargo airplanes relative to the proposal in the 
NPRM, and because the cost estimate is significantly revised, we are 
reopening the comment period to allow the public the chance to comment 
on these proposed changes.

DATES: We must receive comments on this SNPRM by April 24, 2015.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, Attention: Data & Services Management, P. O. Box 
3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, 
extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. 
You may view this referenced service information at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information 
on the availability of this material at the FAA, call 425-227-1221. It 
is also available on the Internet at http://www.regulations.gov by 
searching for and locating Docket No. FAA-2012-0187.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2012-
0187; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Jon Regimbal, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6506; fax: 425-917-6590; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2012-0187; 
Directorate Identifier 2011-NM-094-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We issued an NPRM to amend 14 CFR part 39 by adding an AD that 
would apply to certain The Boeing Company Model 757 airplanes. The NPRM 
published in the Federal Register on March 1, 2012 (77 FR 12506). The 
NPRM proposed to require modifying the fuel quantity indication system 
(FQIS) wiring or fuel tank systems to prevent development of an 
ignition source inside the center fuel tank. We subsequently issued an 
NPRM (77 FR 33129, June 5, 2012) to reopen and extend the comment 
period for an additional 2 months.

Related Service Information Under 1 CFR Part 51

    We have reviewed Boeing Service Bulletin 757-28-0136, dated June 5, 
2014. This service information describes procedures for the built-in 
test equipment test/procedure (BITE check) specified in paragraph 
(h)(1) of this

[[Page 9401]]

supplemental NPRM. For information on the procedures and compliance 
times, refer to this service information. This service information is 
reasonably available; see ADDRESSES for ways to access this service 
information.

Comments

    We gave the public the opportunity to comment on the NPRM (77 FR 
12506, March 1, 2012). The following presents the comments received on 
the NPRM and the FAA's response to each comment.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): Unjustified by 
Risk

    Boeing and Airbus requested that we withdraw the NPRM (77 FR 12506, 
March 1, 2012). Airbus requested that we consider risk levels before 
pursuing anticipated ADs for similar models. Boeing's request was based 
on a determination that the risk posed by the FQIS is not high enough 
to warrant AD action. Boeing described the detailed design features 
that it considers make the failures contributing to the unsafe 
condition unlikely. Boeing added that its own numerical probability 
analysis of the average risk level due to the combination of failures 
required to cause a fuel tank explosion is on the order of one 
catastrophic event per billion flight hours. Boeing pointed out that 
this probability level would meet the certification standard for 
systems contained in section 25.1309(b) of the Federal Aviation 
Regulations (14 CFR 25.1309(b)). Boeing also pointed out that, because 
the Model 757 is out of production and has a limited remaining fleet 
life, the total risk of a catastrophic event occurring in the remaining 
fleet life is approximately 0.5 percent. Boeing also noted that if a 
conductive condition were to exist between the probes or wiring and 
structure, it would be identified by FQIS faults and therefore would 
not be latent for multiple flights.
    We disagree with the request to withdraw the NPRM (77 FR 12506, 
March 1, 2012). Average risk per flight hour and total fleet risk were 
not the safety criteria that drove the FAA to propose the AD. In 
addition to examining average risk and total fleet risk, the FAA 
examines the individual flight risk on the worst reasonably anticipated 
flights. FAA Transport Airplane Risk Assessment Methodology (TARAM) 
Policy Statement PS-ANM-25-05 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/4E5AE8707164674A862579510061F96B?OpenDocument&Highlight=ps-anm-25-05) 
calls for the FAA to assess individual flight safety risk in 
consideration of pre-existing hidden failure conditions and accounts 
for dispatch with inoperative equipment. The TARAM policy classifies a 
flight dispatch condition as ``reasonably anticipated'' if, in absence 
of corrective action, ten or more flights are expected to occur.
    Average risk is an arithmetic average of the risk of a given event 
during all operation of an aircraft fleet, regardless of whether the 
risk actually varies during the operation of the fleet. We use average 
risk analysis to assess whether a risk is acceptable when there is 
little or no variation in risk from flight to flight. Total fleet risk 
is the aggregate sum of all risk throughout a fleet during the 
remaining fleet life. Total fleet risk analysis is meaningful in 
assessing total societal risk, but it does not assess the variation in 
risk between flights or the risk on the worst anticipated flights. 
Individual flight risk as used by the FAA is an assessment of the 
specific safety risk that exists or will exist on the worst reasonably 
anticipated individual flights due to a given issue.
    Individual risk analysis is used by the FAA to determine whether 
the public's expectation for a reasonable level of safety on each 
transport airplane flight is met. An acceptable average risk level and 
acceptable total fleet risk do not ensure that all reasonably 
anticipated flights (flights with known inoperative equipment, flights 
with undetected failures, flights in less-than-ideal but approved and 
expected weather or operational conditions, etc.) will provide the 
minimum level of safety expected by the public. When the safety risk is 
concentrated on flights with a given pre-existing dispatch condition or 
expected operational condition, it is possible to have an unacceptable 
individual flight safety risk on the worst reasonably anticipated 
flights even when the average risk and total fleet risk are acceptable.
    In the case of this SNPRM, the risk due to the current Model 757 
FQIS design architecture is not spread equally among all of the flights 
conducted on the affected airplanes. Instead, the risk is concentrated 
almost entirely on the small subset of flights that occur with a latent 
failure condition pre-existing in the fuel tank. Flights with such a 
latent failure condition and flammable conditions in the center fuel 
tank have been judged by the FAA to be reasonably anticipated to occur 
based on the numerical probability analysis submitted by the 
manufacturer in response to Special Federal Aviation Regulation No. 88 
(``SFAR 88,'' Amendment 21-78, and subsequent Amendments 21-82 and 21-
83) (http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgFAR.nsf/0/EEFB3F94451DC06286256C93004F5E07?OpenDocument) and the flammability 
analysis submitted to support certification of Boeing's flammability 
reduction means (FRM), which Boeing refers to as a nitrogen generation 
system (NGS). For those reasonably anticipated flights, the probability 
of a catastrophic event (or individual flight safety risk) is the 
probability of an additional single failure in the related aircraft 
wiring or equipment sending a high energy signal onto the already 
compromised in-tank circuit(s). The individual flight safety risk of a 
catastrophic event on these flights is in excess of the FAA's threshold 
for an unsafe condition determination contained in the published TARAM 
Policy Statement PS-ANM-25-05 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/4E5AE8707164674A862579510061F96B?OpenDocument&Highlight=ps-anm-25-05).
    As discussed above, this risk of a catastrophic event on those 
flights is due to a single additional failure condition. The risk on 
those flights due to a single failure violates the FAA's general fail-
safe design requirements philosophy for transport airplanes. In 
general, we issue ADs in cases where reasonably anticipated flights 
with pre-existing failures (either due to latent failure conditions or 
allowable dispatch configurations) are vulnerable to a catastrophic 
event due to an additional foreseeable single failure condition. This 
is because the FAA considers operation of flights vulnerable to a 
potentially catastrophic single failure condition to be an excessive 
safety risk to the passengers on those flights. This SNPRM is 
consistent with that continued operational safety philosophy.
    In its comment, Boeing stated that the existing design meets the 
numerical probability requirements of section 25.1309(b) of the Federal 
Aviation Regulations (14 CFR 25.1309(b)), which requires safety 
analysis of systems. Boeing concluded that the existing system would 
need no further risk reduction to meet the requirements of that rule. 
We disagree with this conclusion. First, the existence of a general 
safety standard, even if met by a design, does not in and of itself 
preclude a determination that there is a specific unsafe condition. The 
recognition that compliance with an existing regulation may not be 
sufficient to ensure safety is specifically addressed in type 
certification by section 21.21(b)(2) of the Federal Aviation 
Regulations (14 CFR 21.21.(b)(2)) and

[[Page 9402]]

has often led to changes in regulations to address newly recognized 
unsafe conditions. Second, because Boeing mentioned only that rule, we 
infer that Boeing may be suggesting that section 25.1309(b) of the 
Federal Aviation Regulations (14 CFR 25.1309(b)) is the most relevant 
safety analysis standard applicable to the FQIS. As discussed above, 
even if later changes to section 25.981 of the Federal Aviation 
Regulations (14 CFR 25.981) are not considered and only the original 
certification basis for the Model 757 is applied, there are safety 
standards more specific to powerplant installations including fuel 
tanks and FQIS than section 25.1309(b) of the Federal Aviation 
Regulations (14 CFR 25.1309(b)).
    The original certification basis for Model 757 airplanes included 
section 25.901(c) of the Federal Aviation Regulations (14 CFR 
25.901(c)) (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySectLookup/25.901) at Amendment 25-40. According to 
that subsection, ``For each powerplant and auxiliary power unit 
installation, it must be shown that no single failure or malfunction or 
probable combination of failures will jeopardize the safe operation of 
the airplane. . . .'' (The FQIS is considered to be part of the 
powerplant installation in accordance with the definition in section 
25.901(a) of the Federal Aviation Regulations (14 CFR 25.901(a)).) 
Section 25.901(c) of the Federal Aviation Regulations (14 CFR 
25.901(c)) sets a more stringent applicable standard than that of 
section 25.1309(b) of the Federal Aviation Regulations (14 CFR 
25.1309(b)) for catastrophic failure conditions that are due to latent 
failure conditions combined with a subsequent single failure condition 
(referred to as ``latent-plus-one'' conditions).
    The more stringent intent of section 25.901(c) of the Federal 
Aviation Regulations (14 CFR 25.901(c)) (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySectLookup/25.901) is 
discussed in further detail in the notice of proposed rulemaking and 
the preamble that were published for Amendment 25-102. The FAA's long-
standing practice in applying the ``no single failure or malfunction'' 
clause of section 25.901(c) of the Federal Aviation Regulations (14 CFR 
25.901(c)) has been to apply that standard to all reasonably 
anticipated flights--not simply to an average flight or an ideal 
flight. As such, we examine all conditions: Flights with reasonably 
anticipated pre-existing failure conditions, flights with inoperative 
equipment allowed for dispatch, and flights in adverse environmental 
conditions or other operational conditions for which the airplane is 
approved. If single failure conditions that jeopardize safe operation 
of the airplane (catastrophic or hazardous conditions) are identified 
as part of this examination, the design is considered to be non-
compliant with section 25.901(c) of the Federal Aviation Regulations 
(14 CFR 25.901(c)).
    Finally, the SFAR 88 AD-decision policy (Policy Memo ANM-100-2003-
112-15) (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/DC94C3A46396950386256D5E006AED11?OpenDocument&Highlight=anm-100-2003-112-15) classifies a ``latent-plus-one'' condition in a high 
flammability fuel tank as an unsafe condition requiring corrective 
action. That policy actually provides some relief from the latent-plus-
one criteria contained in the airworthiness regulations.
    We have not changed this SNPRM regarding this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): Not Supported by 
Risk Analysis

    Airlines for America (A4A) proposed that we re-evaluate the NPRM 
(77 FR 12506, March 1, 2012) because it is ``not founded on a data-
based risk analysis.'' A4A stated that the FAA determined that an 
unsafe condition exists based only on non-compliance with one SFAR 88 
criterion. A4A noted that the design approval holder, Boeing, has 
performed a numerical probability analysis and has calculated that the 
probability of a fuel tank explosion due to the FQIS issue is 
approximately one event per billion flight hours, with cargo airplanes 
being slightly better due to a lower average tank flammability. A4A 
also stated that existing ignition-prevention ADs have reduced the 
overall risk of an ignition event to a level that questions the need 
for FQIS modification. We infer that the commenter is requesting that 
we withdraw the NPRM.
    We disagree to withdraw the NPRM (77 FR 12506, March 1, 2012). We 
performed a qualitative risk assessment in accordance with our 
published SFAR 88 unsafe condition determination policy based on 
Boeing's submitted SFAR 88 design review, and determined that the FQIS 
design on the Model 757 series airplanes presents an unsafe condition 
and that AD action was warranted under that policy. We also performed a 
data-based numerical risk analysis using data provided by the 
manufacturer, and assessed the risk under the transport airplane unsafe 
condition criteria in the TARAM policy currently used by the FAA. Our 
risk analysis determined that the risk of an explosion event due to an 
FQIS latent-plus-one failure condition is not evenly shared by all 
flights of airplanes of the affected design. Instead, the risk of an 
FQIS-related fuel tank ignition event is largely concentrated on the 
subset of flights that occur with a pre-existing latent failure 
condition and that operate with flammable conditions in the center fuel 
tank. Based on Boeing's data, such flights are reasonably anticipated 
to occur.
    For those flights, the risk exceeds the allowable threshold for 
individual flight safety risk in the TARAM policy. In addition, that 
risk on those flights is due to a single additional failure, which is 
inconsistent with the fail-safe design philosophy; that philosophy is 
fundamental to the excellent safety record of transport airplanes. (See 
FAA Advisory Circular (AC) 25.1309-1A, ``System Design and Analysis,'' 
dated June 21, 1998 (http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2025.1309-1.pdf), for a discussion of the fail-
safe design philosophy.) We would normally classify either of those 
conditions as an unsafe condition. Based on this risk analysis, we have 
determined that the individual flight safety risk due to this issue on 
the worst anticipated flights does not meet the minimum level of safety 
required by the FAA and expected by the public. We have not changed 
this SNPRM regarding this issue.

Request To Withdraw or Delay NPRM (77 FR 12506, March 1, 2012): Need 
Detailed Risk Assessment

    FedEx requested that we revise the NPRM (77 FR 12506, March 1, 
2012) to provide a numerical risk assessment justifying the proposed 
action. UPS made a similar comment. UPS stated that, if the FAA has 
gathered new data since the issuance of the ``Reduction of Fuel Tank 
Flammability in Transport Category Airplanes'' rule (73 FR 42444, July 
21, 2008) (http://www.thefederalregister.org/fdsys/pkg/FR-2008-07-21/pdf/E8-16084.pdf), referred to as the Fuel Tank Flammability Reduction (FTFR) 
rule, the FTFR working group should be reconvened in order to 
collaborate and discuss the proposed safety risk, assess the risk 
statistically, evaluate solutions and options, and establish accurate 
cost and economic impact for the options. FedEx provided an analysis 
showing that the total risk of a tank explosion due to this issue on 
the fleet of Model 757 cargo airplanes is relatively low. We infer that 
the commenters are requesting that we withdraw or delay the NPRM.

[[Page 9403]]

    We disagree with the request to withdraw the NPRM (77 FR 12506, 
March 1, 2012), pending review of the FAA's numerical risk assessment 
by the ``FTFR working group.'' The Aviation Rulemaking Advisory 
Committee (ARAC) Fuel Tank Harmonization Working Group (FTHWG) was 
tasked to recommend new rulemaking to eliminate or significantly reduce 
the risk of exposure to flammable fuel-air mixtures in fuel tanks. The 
ARAC FTHWG issued its final report in 1998. The subsequent ARAC Fuel 
Tank Inerting Harmonization Working Group (FTIHWG) was tasked to 
provide data needed for the FAA to evaluate the feasibility of 
implementing regulations that would require eliminating or 
significantly reducing the development of flammable vapors in fuel 
tanks on transport-category airplanes. This effort was an extension of 
the previous work performed by the FTHWG. The ARAC FTIHWG issued its 
final report in 2002. The FAA's work in developing the SFAR 88 
corrective action decision policy and in determining specific unsafe 
conditions was outside the scope and charter of these working groups 
that contributed to the FTFR rule (73 FR 42444, July 21, 2008). We 
determined that an unsafe condition exists in accordance with the SFAR 
88 corrective action decision policy and TARAM policy. We have provided 
a summary of our risk assessment as discussed in the responses to 
``Request to Withdraw NPRM (77 FR 12506, March 1, 2012): Unjustified by 
Risk'' and ``Request to Withdraw NPRM (77 FR 12506, March 1, 2012): Not 
Supported by Risk Analysis'' in this SNPRM. As explained previously 
(see ``Request to Withdraw NPRM (77 FR 12506, March 1, 2012): 
Unjustified by Risk'' in this SNPRM), the FAA determined the unsafe 
condition based on the unacceptable risk on anticipated flights with a 
latent FQIS failure and flammable fuel tank conditions, not the total 
fleet risk. We have not changed this SNPRM regarding this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): No Unsafe 
Condition

    UPS stated that an SFAR 88 working group analyzed potential fuel 
tank ignition sources and that maintenance programs were revised using 
MSG3 methodology to meet the revised criteria in ``14 CFR 25.981(3).'' 
(We assume UPS intended to refer to section 25.981(a)(3) of the Federal 
Aviation Regulations (14 CFR 25.981(a)(3))) (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716).) UPS stated that the unsafe 
condition identified in the NPRM is inconsistent with the working group 
analysis and lacks new data or evidence indicating that ``excessive 
flammability or other known unsafe condition exists, or is likely to 
develop.'' Finally, UPS made the following observation about the NPRM:

    The NPRM fails to consider the beneficial effects of the timing 
and effects of the maintenance action in response to a single in-
tank or out-of-tank failure mode, or the beneficial effects of 
previous airworthiness directives and other SFAR 88 related actions 
taken to mitigate the proposed risk and reduce the probability.

    We infer that the commenter is requesting that we withdraw the NPRM 
(77 FR 12506, March 1, 2012). We disagree with the request to withdraw 
the NPRM. The FAA has performed a risk assessment and has determined 
that an unsafe condition does exist, both from a design architectural 
standpoint and a numerical risk standpoint. The basis for that 
determination is discussed in detail in the responses to ``Request to 
Withdraw NPRM (77 FR 12506, March 1, 2012): Unjustified by Risk'' and 
``Request to Withdraw NPRM (77 FR 12506, March 1, 2012): Not Supported 
by Risk Analysis'' in this SNPRM.
    The requirements of section 25.981(a)(3) of the Federal Aviation 
Regulations (14 CFR 25.981(a)(3)) cannot be met with an approved 
maintenance program only. While an appropriate maintenance program is 
required, section 25.981(a)(3) of the Federal Aviation Regulations (14 
CFR 25.981(a)(3)) has the effect of setting minimum requirements for 
the design architecture and the reliability of system elements. The 
Model 757 FQIS as originally designed does not meet all of those 
requirements. Previous AD actions, other than the required maintenance 
program revisions included in AD 2012-12-15, Amendment 39-17095 (77 FR 
42964, July 23, 2012) (which superseded AD 2008-10-11, Amendment 39-
15517 (73 FR 25974, May 8, 2008)), have no effect on the level of 
individual flight risk that has been determined to be an unsafe 
condition. Some of the airworthiness limitations (AWLs) introduced by 
AD 2012-12-15 will reduce the rate of introduction of additional risks 
due to future maintenance errors or modifications compromising required 
design features, but are not expected to prevent all errors. Those AWLs 
do not address problems that may already exist or develop on in-service 
airplanes separate from maintenance activity, and they do not address 
the basic non-compliant aspects of the original FQIS design 
architecture. Those AWLs therefore would not have a significant effect 
on either the number of flights that occur with a latent failure 
condition or the FQIS-related fuel tank explosion risk level on those 
flights estimated in the FAA's risk assessment. We have not changed 
this SNPRM regarding this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): No Unsafe 
Condition

    Airbus acknowledged that the latent-plus-one scenarios that 
prompted the unsafe condition determination are a technical 
possibility, but stated that the failure combinations that can create 
an ignition source are extremely improbable. Airbus also stated that 
AD-required airworthiness limitations related to FQIS have 
significantly reduced the likelihood of an FQIS-related fuel tank 
ignition event. We infer that Airbus is requesting that we withdraw the 
NPRM (77 FR 12506, March 1, 2012) based on Airbus's contention that no 
unsafe condition exists.
    We agree to clarify the likelihood that the unsafe condition could 
occur. The FAA's unsafe condition determination was not based on an 
assessment of average risk. We agree that the average risk of a fuel 
tank explosion on the Model 757 is likely to be lower than the 
numerical guidance for ``extremely improbable'' of 1.0x10E-9 per flight 
hour. We also agree that the average risk was likely reduced by AD-
required airworthiness limitations that specify extra checks after in-
tank work, and adequate separation of newly installed out-of-tank 
wiring from FQIS wiring.
    As discussed in ``Request to Withdraw NPRM (77 FR 12506, March 1, 
2012): Unjustified by Risk'' in this SNPRM, however, the FAA's unsafe 
condition determination was driven by the identification of an 
unacceptable level of individual risk that exists on flights that are 
anticipated to occur with a pre-existing latent in-tank failure 
condition and with a flammable center fuel tank. In the remaining life 
of the affected airplanes, a significant number of such flights are 
reasonably anticipated to occur--even with the improvements expected 
under the AWLs required by AD 2012-12-15, Amendment 39-17095 (77 FR 
42964, July 23, 2012). For those flights, a fuel tank explosion can be 
caused by an additional single wiring failure. In addition, the 
manufacturer's estimated probability of such a failure (the additional 
single wiring failure) significantly exceeds the FAA's unsafe condition 
numerical threshold for individual flight risk. The probability of

[[Page 9404]]

a fuel tank explosion on those flights is not reduced by the existence 
of the above-mentioned AWLs. The AWL that requires extra checks after 
in-tank work has been done has the potential to reduce the number of 
flights with a pre-existing in-tank failure condition. The AWL that 
requires newly installed wiring to meet separation standards should 
prevent a significant increase in the risk on those flights that would 
have resulted from the installation of additional, inadequately 
separated wiring.
    We have not changed this SNPRM regarding this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012) Based on Similar 
Rulemaking for Cargo Airplanes

    ASTAR Air Cargo (ASTAR) requested that we withdraw the NPRM (77 FR 
12506, March 1, 2012). In support of its request, ASTAR cited the TWA 
Flight 800 accident investigation and its finding that the most 
probable cause of the accident was a fuel tank explosion due to a 
latent-plus-one failure of the FQIS. ASTAR stated that the FAA had 
proposed the FTFR rule (73 FR 42444, July 21, 2008) to mitigate the 
risk of fuel tank explosions, and that cargo airplanes had been 
exempted from that requirement based on a cost-benefit analysis. ASTAR 
argued that, because the basis for exclusion of all cargo aircraft from 
the FTFR rule has not changed, all cargo aircraft should be exempt from 
any corrective action for the FQIS latent-plus-one issues, and the NPRM 
(77 FR 12506, March 1, 2012) should be withdrawn.
    We disagree with the request. We have determined that an unsafe 
condition requiring corrective action exists in the Model 757 FQIS. The 
FTFR rule (73 FR 42444, July 21, 2008) was proposed not because of FQIS 
issues specifically, but because of the history of fuel tank explosions 
in the transport airplane fleet due to various causes, and an 
acknowledgement that industry and the FAA may not be able to anticipate 
and prevent all of the fuel tank ignition sources that may arise due to 
design and maintenance issues in the life of a fleet of airplanes.
    The intent of the FTFR rule (73 FR 42444, July 21, 2008) was to 
reduce the overall exposure to flammable fuel tank conditions in the 
fleet by approximately one order of magnitude with the expectation that 
this would have a significant impact on the rate of fuel tank 
explosions in the future due to unanticipated causes. In promulgating 
this improvement in the safety standards, the FAA acknowledged that 
installation of FRM or ignition mitigation means on a given airplane in 
accordance with the FTFR rule would be sufficient to address the FQIS 
latent-plus-one unsafe condition. The FTFR rule was not intended to 
prevent the FAA from addressing that unsafe condition on airplanes that 
would not be affected by the FTFR rule. This was clearly stated in the 
preamble to the FTFR rule. We have not changed this SNPRM regarding 
this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): Underestimated 
Economic Impact

    Several commenters requested that we withdraw the NPRM (77 FR 
12506, March 1, 2012) because the FAA's cost estimate was too low. A4A 
estimated that the costs associated with the NPRM would be up to 3 
times the $100,000 to $200,000 estimated by the FAA, and would be 
comparable with the cost of Boeing's NGS installation. Goodrich pointed 
out that any redesigned FQIS would likely be subject to the current 
requirements of section 25.981 of the Federal Aviation Regulations (14 
CFR 25.981), resulting in higher costs than estimated by the FAA. A4A 
speculated that these higher costs were the reason the NGS was 
acknowledged as a method of compliance in the NPRM. A4A and UPS stated 
that the FAA appears to be using the NPRM as a method to require the 
installation of Boeing's NGS (or equivalent actions) on airplanes that 
were not included in the applicability of the FTFR rule (73 FR 42444, 
July 21, 2008) based on a cost-benefit analysis.
    Although we disagree to withdraw the NPRM, we agree with some of 
the commenters' assertions. We agree that our original cost estimate 
was low. We agree to adjust the cost estimate, based on the information 
provided by the commenters, as discussed below under ``Request to 
Revise Cost Estimate Based on New Data.'' Our original estimate was 
based on information provided previously by manufacturers of original 
equipment FQIS, retrofit FQIS, and both original equipment and 
aftermarket transient suppression and isolation devices. Our current 
estimate has been increased to reflect the written comments from and 
further discussions with Boeing and Goodrich. There is no change to our 
determination that an unsafe condition exists. We are therefore 
proceeding with this AD action based on the identified corrective 
actions that will address the unsafe condition.
    We disagree with the characterization that we are using the AD 
process to require an FRM to be installed on airplanes that were 
excluded from the FTFR rule (73 FR 42444, July 21, 2008) because 
inclusion could not be justified in a cost-benefit analysis. The FTFR 
rule was intended to enhance the airworthiness standards in a manner 
that would increase the level of safety for affected airplanes over 
that ensured by the existing regulations. That enhancement was expected 
to result from an increased level of protection from ignition sources 
that had not been identified by manufacturers in their safety analyses. 
That enhancement of the airworthiness standards was required to be 
justified by a cost-benefit analysis. Cargo airplanes were excluded 
because the FTFR rule safety enhancement could not be justified for 
those airplanes from a cost-benefit standpoint.
    This SNPRM would not require a safety enhancement over the level of 
safety required by previous standards. Instead, this SNPRM addresses an 
unsafe condition that was identified from the manufacturer's SFAR 88 
safety analysis using the FAA's published corrective action decision 
criteria for SFAR 88 identified design issues (see section 25.981(a)(3) 
of the Federal Aviation Regulations (14 CFR 25.981(a)(3) (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716). We deferred taking action on 
this unsafe condition until after the FTFR rulemaking activity because 
the installation of an FRM would sufficiently address the FQIS latent-
plus-one unsafe condition. Now that the FTFR rulemaking process is 
complete, we are resuming our activity to address these unsafe 
conditions via AD actions. The Boeing NGS has been acknowledged as a 
method of compliance in this SNPRM because the Boeing NGS is an 
available design that the FAA knows would address the unsafe condition. 
No additional change was made to this SNPRM as a result of this 
comment.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012) Due to Its Hidden 
Effects

    A4A requested that we withdraw the NPRM (77 FR 12506, March 1, 
2012) because of certain hidden effects that may not have been 
anticipated by the FAA. A4A pointed out that some operators are already 
anticipating difficulty in meeting the deadlines for compliance with 
the FTFR rule (73 FR 42444, July 21, 2008). Based on A4A's assumption 
that airlines would comply with the NPRM by incorporating Boeing's 
current NGS design, A4A expressed concern that using Boeing's NGS for 
these additional airplanes would potentially exceed the rate at

[[Page 9405]]

which industry can modify the fleet affected by the planned ADs and the 
FTFR rule. A4A also noted that the compliance time for the NPRM would 
overlap the compliance period for the FTFR rule.
    While we disagree with the request to withdraw the NPRM, we agree 
with some of the assertions made by the commenter. We agree with the 
concern that this AD action has the potential to further burden the 
operators and modifiers that are working to meet the FRM operating rule 
deadlines, because some additional airplanes are likely to be modified 
by installing FRM such as Boeing's NGS. But since we issued the NPRM 
(77 FR 12506, March 1, 2012), two factors have changed that reduce 
A4A's concern. First, we have identified a less costly option for cargo 
airplanes, which most cargo operators are expected to prefer over 
installation of FRM. This is expected to result in significantly fewer 
airplanes competing for FRM modification resources. Second, this AD 
action has been delayed due to numerous factors, including the number 
of comments, the development of a different corrective action option, 
and the resultant need to extend the comment period to allow the public 
the chance to comment on these proposed changes.
    Also, as discussed below under ``Request to Extend Compliance Time 
Pending Issuance of Service Information,'' we have extended the 
proposed compliance time by 12 months. These delays and changes will 
result in the AD compliance deadline being at least 3 years beyond the 
final compliance deadline of the FTFR rule (73 FR 42444, July 21, 
2008). Similar planned ADs for other models have been similarly 
delayed. We have determined that the industry modification capacity 
will be sufficient to support the modification of the expected 
additional airplanes receiving FRM within the new proposed compliance 
time. We have not changed this SNPRM further regarding this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): Potential 
Significant Rule

    A4A stated that the combined costs of the NPRM (77 FR 12506, March 
1, 2012) and other anticipated ADs for U.S. airplane models with an 
FQIS latent-plus-one issue would exceed $177 million and would require 
a cost-benefit analysis. We infer that the commenter is requesting we 
withdraw the NPRM (77 FR 12506, March 1, 2012) on the basis that the 
planned ADs for various models, if combined, would qualify as a 
significant rule that would require a cost-benefit analysis.
    We disagree with the request. First, in assessing whether an AD is 
a significant rule in accordance with FAA policy, we do not combine the 
cost of multiple planned ADs for different airplanes, even when the 
design issues and unsafe conditions addressed are similar. Second, the 
changes discussed previously in this SNPRM will significantly reduce 
the cost impact. We have made no further changes to this SNPRM 
regarding this issue.

Request To Withdraw NPRM (77 FR 12506, March 1, 2012): Inadequate 
Notice to Public

    A4A recommended that we provide information on any other designs 
that have been reviewed under SFAR 88, and provide industry with 
information regarding their planned disposition. A4A asserted that, 
during the FTFR rulemaking activity, we did not provide notice to the 
industry that we still intended to address the FQIS issues identified 
via SFAR 88. We infer that A4A is requesting that we withdraw the NPRM 
(77 FR 12506, March 1, 2012) based on inadequate notice to the public 
and the chance to comment on the proposal. The commenter stated that 
the preamble of the FTFR rule (73 FR 42444, July 21, 2008) was unclear 
regarding whether AD actions would be taken to address the FQIS issues 
on airplanes that were not required to incorporate FRM.
    We disagree with the request to withdraw the NPRM (77 FR 12506, 
March 1, 2012). We determined that an unsafe condition exists. FTFR 
rulemaking was done because the FAA recognized the benefit for the 
specific design changes involving incorporation of FRM required by the 
FTFR rule (73 FR 42444, July 21, 2008) to enhance fuel tank safety. 
Because the FTFR final rule requires action on only a subset of the 
airplanes that have the FQIS unsafe condition, we are taking action to 
address the remaining airplanes that will continue to have the unsafe 
condition if no further corrective action is taken.
    The commenter has taken the statement from the FTFR preamble out of 
context. In fact, the paragraph from which the commenter quoted 
specifically states that the FAA expected to take AD action to address 
FQIS issues identified through SFAR 88 analyses. The paragraph simply 
states that the proposed FRM has the potential to reduce the industry 
cost associated with those expected ADs because the installation of an 
FRM likely would eliminate the need for action to further address the 
FQIS issue with AD actions. The purpose of that statement was to note 
that there would be some cost savings to industry resulting from the 
elimination of other actions required to address an unsafe condition 
for the airplanes affected by the proposed rules, and to point out that 
the FAA did not take credit for those potential cost reductions in 
assessing the cost of the FTFR rule (73 FR 42444, July 21, 2008) 
because the costs were not well understood at the time. That statement 
was not a commitment by the FAA to reverse its intentions to address an 
identified unsafe condition on the airplanes that are not required to 
incorporate FRM. We have not changed this SNPRM regarding this issue.

Request for Cost-Benefit Analysis

    Boeing, FedEx, Airbus, ASTAR Air Cargo, and A4A requested that we 
perform a cost-benefit analysis for the NPRM (77 FR 12506, March 1, 
2012) and publish the results. Airbus stated that its own cost 
estimates exceed those used by the FAA for the FTFR rule (73 FR 42444, 
July 21, 2008) cost-benefit analysis that ended up excluding cargo 
airplanes. A4A and ASTAR Air Cargo requested that the NPRM be withdrawn 
until a cost-benefit analysis is performed. The commenters suggested 
that a cost-benefit analysis would show that the NPRM cannot be 
justified because the costs of the proposed actions would exceed the 
monetary value of the AD's safety benefits. The commenters cited the 
cost-benefit analysis that was performed to justify the FTFR rule, and 
pointed out that a requirement for FRM could not be justified for the 
airplanes that would be affected by the proposed AD.
    We infer that, pending a full cost-benefit analysis, these 
commenters are requesting that we either withdraw the NPRM or delay 
this action further until a cost-benefit analysis demonstrates that an 
AD is justified in this case. We disagree. The FAA's process and legal 
obligations for introducing new airworthiness standards are different 
from those for initiating an AD to address an unsafe condition in an 
existing product. In addition, the commenters' assertions were based on 
the assumption that the only design solution that would be made 
available to address the solution would be an FRM, or another solution 
of similarly high cost.
    When we propose a new airworthiness standard, as in the case of the 
FTFR rule (73 FR 42444, July 21, 2008), we are required to perform a 
cost-versus-benefit comparison to justify the application of the new 
standard. The

[[Page 9406]]

decision in that rulemaking action--to not require FRM installation on 
cargo airplanes--was based in significant part on cost estimates that 
industry provided to show that AD-required FQIS design changes would be 
far less costly than installing FRM on cargo airplanes. We specifically 
considered the option to not require retrofit of cargo airplanes with 
FRM because of the expectation that alternative design solutions to 
address the specific, known unsafe condition of FQIS latent-plus-one 
vulnerability would still be required through AD actions. For this AD 
action, however, industry submitted written comments and made verbal 
statements that the cost of an FQIS design solution would be comparable 
to, and possibly greater than, the cost of its FRM modification.
    In general, a full cost-benefit analysis is rarely required for an 
AD. As a matter of regulation, in order to be airworthy, an aircraft 
must conform to its type design and be in a condition for safe 
operation. The type design is approved only after the FAA makes a 
determination that the design complies with all applicable 
airworthiness requirements. In adopting and maintaining those 
requirements, the FAA has already made the determination that those 
requirements establish a level of safety that is cost beneficial. A 
finding of an unsafe condition that warrants AD action means that this 
cost-beneficial level of safety is no longer being achieved, and the 
required AD actions are necessary to restore that level of safety. 
Because this level of safety has already been determined to be cost 
beneficial and does not add an additional regulatory requirement, a 
full cost-benefit analysis for each AD would be redundant and 
unnecessary.
    We have not changed this SNPRM regarding this issue.

Request To Revise Applicability Statement To Clarify the Intent of the 
Rule for Non-U.S.-Registered Airplanes

    The European Aviation Safety Agency (EASA), the Technical Agent for 
the Member States of the European Community, requested that we revise 
the proposed applicability. Specifically, EASA requested that we add 
Model 757 airplanes that did not have FRM installed in production. EASA 
further requested that we exclude airplanes equipped with FRM that meet 
the FAA's FTFR rule (73 FR 42444, July 21, 2008). EASA stated that it 
has not issued an operating regulation corresponding to the FAA's 
requirements for retrofitting FRM in the FTFR rule. EASA noted that, at 
least for European operators, the unsafe condition would not be 
required to be addressed for airplanes that would have been subject to 
the FTFR rule in the U.S., and suggested that EASA might have to issue 
an AD (instead of adopting the FAA AD), with similar technical content, 
but extending the applicability to the entire Model 757 fleet in 
Europe.
    We agree to revise the applicability. EASA is correct that the 
unsafe condition potentially affects all Model 757 airplanes, whereas 
the applicability statement in the NPRM (77 FR 12506, March 1, 2012) 
could be interpreted as not covering airplanes in passenger service 
that are not operated under parts 121, 125, or 129 of the Federal 
Aviation Regulations (14 CFR part 121, 125, or 129). The EASA comment 
makes it apparent that the proposed applicability statement may be 
unclear to some operators and regulatory authorities. While the 
applicability statement in the NPRM is technically correct (e.g., an 
EASA operator is not operating under those FAA operating rules and 
therefore would have been subject to the AD), we now agree that there 
is a potential for confusion that can be eliminated by more directly 
stating the requirement and applicability in a manner similar to that 
proposed by EASA in their comment. We have changed the applicability in 
this SNPRM to all Model 757 airplanes except for airplanes equipped 
with an FRM approved by the FAA as compliant with the FTFR requirements 
of section 26.33(c)(1) of the Federal Aviation Regulations (14 CFR 
26.33(c)(1)), as discussed below. As with any required equipment, the 
FRM must be operational with the exception of any relief granted under 
master minimum equipment list (MMEL) provisions.
    With the clarification in paragraph (c), ``Applicability,'' of this 
SNPRM, we have determined that paragraph (h), ``Optional Installation 
of Flammability Reduction Means,'' of the NPRM would be superfluous and 
is no longer necessary. Paragraph (c) of this supplemental NPRM, as 
revised, would not apply to airplanes equipped with FRM.

Requests To Withdraw NPRM (77 FR 12506, March 1, 2012) Based on 
Applicability

    Boeing and ASTAR Air Cargo requested that we withraw the NPRM (77 
FR 12506, March 1, 2012) because cargo airplanes on average have a 
lower flammability exposure due to a larger portion of night operations 
(with resultant cooler outside air temperatures) and a lower rate of 
utilization of the cabin air conditioning system on the ground. Boeing 
stated that operation of the air conditioning system on the ground 
significantly contributes to the heating of the center fuel tank. 
Boeing's analysis estimated a fleet average flammability for the center 
fuel tanks of the cargo airplane fleet of 50 percent of the level for 
the passenger fleet. Boeing also noted that cargo airplanes generally 
accumulate flight hours at a lower rate than passenger airplanes.
    We disagree with the request to withdraw the NPRM (77 FR 12506, 
March 1, 2012).
    We acknowledge that the increased night operation and reduced use 
of the air conditioning system on the ground reduce the average 
flammability exposure for the fleet of cargo airplanes relative to the 
fleet of passenger airplanes. That reduction in fleet average 
flammability, however, is not sufficient to allow the center fuel tanks 
on those airplanes to be classified as low flammability fuel tanks. The 
FAA's determination that an unsafe condition exists for the cargo 
airplanes as well as passenger airplanes was driven by the FAA's 
individual risk safety decision criteria rather than an average risk or 
fleet risk criterion. There is no difference in the individual flight 
risk on the worst anticipated flights between passenger airplanes and 
cargo airplanes due to this issue. The worst anticipated flights in 
either case involve a pre-existing latent in-tank failure and operation 
with flammable conditions in the center fuel tank. Flights with that 
combination of conditions are anticipated to occur in both the 
passenger fleets and cargo fleets (although at a somewhat lower 
relative rate on cargo airplanes, for the reasons cited by the 
commenters).
    For those flights, a fuel tank explosion could occur due to a 
single failure in the airplane wiring or the FQIS processor that 
conducts a high level of electrical energy onto circuits that enter the 
fuel tank. As discussed previously in the response to ``Request to 
Withdraw NPRM (77 FR 12506, March 1, 2012): Unjustified by Risk,'' this 
is not consistent with the FAA's fail-safe design philosophy for 
transport airplanes. In addition, the numerical probability of the 
single failure as estimated by the manufacturer and the FAA 
significantly exceeds the unsafe condition threshold for individual 
flight risk in the FAA's TARAM) Policy Statement PS-ANM-25-05 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/4E5AE8707164674A862579510061F96B?OpenDocument&Highlight=ps-anm-25-05). 
We have therefore determined that an unsafe condition does exist on 
cargo

[[Page 9407]]

airplanes even in consideration of the lower fleet exposure factors 
cited by the commenters.
    While we have determined that this unsafe condition requires 
corrective action, we have identified additional corrective action 
options that we expect will be significantly less costly to incorporate 
than the originally proposed requirement. We have determined that this 
additional corrective action option is not suitable for passenger 
airplanes because it does not provide a sufficient level of risk 
reduction for passenger operations. The FAA normally does not 
differentiate between the safety requirements or corrective action 
requirements for cargo airplanes and passenger airplanes. However, 
after reviewing all of the comments on the estimated high cost of the 
corrective action and the uncertainty in those estimates, we examined 
other options for less costly risk reduction on cargo airplanes. We 
identified an option that provides significant risk reduction at a per-
airplane cost that is estimated to be less than one-quarter of the cost 
of the original proposal (77 FR 12506, March 1, 2012). The amount of 
risk reduction from this option is not at this time considered to be 
adequate to address the unsafe condition for passenger airplanes.
    In this case, the FAA is proposing to accept a higher level of 
individual flight risk exposure for cargo flights that are not fail-
safe due to the absence of passengers and the resulting significant 
reduction in occupant exposure on a cargo airplane versus a passenger 
airplane, and due to relatively low estimated individual flight risk 
that would exist on a cargo airplane after the corrective actions are 
taken. The FAA has allowed a higher risk level to exist on cargo 
airplanes due to other issues, and applies a slightly less stringent 
numerical fleet risk threshold standard for unsafe conditions in the 
published TARAM policy. Because this is an unusual determination, we 
have reopened the comment period to give affected operators, pilots, 
and the public the opportunity to comment on this proposal.
    We expect that the optional wire separation design change to 
support compliance with the proposed AD for cargo airplanes will 
involve the manufacturer or any other modifier petitioning for a 
partial exemption from the ``latent-plus-one'' requirements of sections 
25.901(c) and 25.981(a)(3) of the Federal Aviation Regulations (14 CFR 
25.901(c) and 14 CFR 25.981(a)(3)). We have informed the manufacturer 
that we are open to granting such an exemption, and they indicated 
their willingness to make such a petition.
    We have added new paragraph (h) in this SNPRM to allow repetitive 
FQIS built-in test equipment (BITE) checks and modification of the 
airplane by separating FQIS wiring from other aircraft wiring that is 
not intrinsically safe (in a manner acceptable to the FAA) as an 
additional option for airplanes used exclusively for cargo operations. 
We have redesignated subsequent paragraphs of this SNPRM accordingly.

Request To Change Applicability To Address Unsafe Condition on 
Airplanes With FRM

    National Air Traffic Controllers Association (NATCA) requested that 
we revise the NPRM (77 FR 12506, March 1, 2012) to include airplanes on 
which FRMs were incorporated either voluntarily or to comply with the 
FTFR rule (73 FR 42444, July 21, 2008). NATCA noted that the 
introduction of FRM on such airplanes only reduces the fraction of time 
the airplane is operated with flammable conditions in its fuel tanks, 
but does not eliminate flammable operation. NATCA further noted that 
FAA operating rules allow limited operation of the airplane with the 
FRM inoperative. NATCA added that the likelihood of a fuel tank 
explosion during operation with flammable tanks is similar regardless 
of whether an FRM is installed.
    We disagree with the request. We have developed and published 
policy for determination of unsafe conditions and the need for 
corrective actions during the evaluation of SFAR 88 fuel tank safety 
review findings. The decision to allow FRM as an acceptable mitigating 
action for the identified unsafe condition is consistent with that 
policy. We acknowledge NATCA's point that, if no actions are taken on 
an airplane to correct the FQIS latent-plus-one issue other than 
installation of an FRM, flights on that airplane where FRM is 
inoperative or ineffective would have the same risk of a fuel tank 
explosion due to the FQIS latent-plus-one issue as flights on an 
airplane with no FRM installed. However, the published unsafe condition 
criteria (section 25.981(a)(3) of the Federal Aviation Regulations (14 
CFR 25.981(a)(3)) (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716) 
differentiate between low- and high-flammability fuel tanks, with a 
higher level of conservatism applied to high-flammability tanks.
    The criteria recognize that low-flammability tanks are still 
flammable for a portion of their operating time, and the criteria 
include ignition prevention thresholds commensurate with that level of 
flammability. The regulatory performance standard for FRMs is 
equivalent to the flammability of a conventional aluminum wing tank, 
which is the benchmark for the definition of a low-flammability tank. 
We have therefore determined that it is appropriate to treat ignition 
sources in center fuel tanks with compliant FRMs the same way they 
would be treated for a tank that has inherent low flammability. Because 
the FQIS latent-plus-one vulnerability for Model 757 airplanes was 
classified as a theoretical vulnerability and not as a condition known 
to have occurred, the SFAR 88 corrective action policy does not require 
corrective action for that condition in low-flammability fuel tanks. 
The installation of an FRM causes the center fuel tank to meet the 
criteria for classification as a low-flammablity fuel tank, and 
therefore FRM installation was considered to be acceptable mitigating 
action. We have not changed this SNPRM regarding this issue.

Request To Remove Requirement for Goodrich FQIS

    Goodrich stated that its FQIS fuel height and dielectric sensor 
interface circuitry presently meets the energy, voltage, and current 
limits specified in FAA AC 25.981-1C, ``Fuel Tank Ignition Source 
Prevention Guidelines,'' dated September 19, 2008 (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716). Goodrich stated that the system 
design would require multiple serial failures to enable a fault to 
propagate to the tank, resulting in the combination of those failures 
being extremely improbable on average. Goodrich added that the system 
built-in test detects open circuits and short circuits in the sensors 
and aircraft wiring, including shorts to structure. Goodrich stated 
that there have been no failures in service in which the Goodrich FQIS 
exposed the fuel tank to an unsafe condition. Goodrich asked whether 
the actual system operation and service life have been considered in 
the evaluation of the probability of an unsafe condition and the 
mitigation provided by the present Goodrich FQIS.
    We infer that the commenter is requesting that we revise the NPRM 
(77 FR 12506, March 1, 2012) to eliminate any requirement for 
corrective action for airplanes equipped with a Goodrich FQIS. We 
partially agree. The Goodrich system is recognized as having 
significant improvements relative to the

[[Page 9408]]

original 757 system developed by another manufacturer. We recognize 
that the Goodrich FQIS has the ability to identify a significant 
portion of the potential latent in-tank failure conditions that can 
occur inside the fuel tanks. Those conditions, however, are detected 
and corrected only when the built-in test capability is activated 
during maintenance. Currently, activating the built-in test features is 
required only when troubleshooting an FQIS problem that has become 
apparent to flight or maintenance crew. This still potentially leaves 
significant latency periods for those failures.
    We have agreed that the Goodrich processor has sufficient circuit 
isolation such that the processor itself is not expected to create hot 
short conditions in tank circuits, and is not expected to pass energy 
from non-tank-side low-voltage hot shorts onto tank-side circuits. 
There remains, however, a significant potential for a single failure 
causing a hot short onto tank-side circuits, or a single failure 
causing a high-voltage hot short onto non-tank-side circuits to cause 
non-intrinsically safe energy, voltage, or current levels to be 
conducted into the fuel tanks. The latent-plus-one concern therefore 
still exists even with the additional detection capabilities that exist 
in the Goodrich FQIS. We have determined this concern requires 
corrective action in accordance with the SFAR 88 corrective action 
decision policy discussed previously. We disagree with the request to 
revise this SNPRM to eliminate any requirement for corrective action 
for airplanes equipped with a Goodrich FQIS because we have determined 
that an unsafe condition requiring corrective action exists on the 
Goodrich FQIS-equipped airplanes even after considering the differences 
between the Goodrich FQIS and the original 757 system developed by 
another manufacturer. We have not changed this SNPRM regarding this 
issue.

Request To Clarify Affected Tanks

    FedEx requested that we revise the NPRM (77 FR 12506, March 1, 
2012) to clarify that only the center fuel tank is affected. FedEx 
stated that the proposed wording could be interpreted as applying to 
all tanks.
    We agree to clarify the intent of this SNPRM. The FQIS wiring and 
related system components are to be modified to the extent necessary to 
prevent the development of an ignition source in the center fuel tank 
due to FQIS failure conditions. If modification of wing tank-related 
components is necessary to prevent an ignition source in the center 
fuel tank (for example, because of common wiring between the tanks), 
then that modification would be required. Paragraph (g) of this SNPRM 
already states this (``modify the FQIS wiring or fuel tank systems to 
prevent development of an ignition source inside the center fuel 
tank''). A change to this SNPRM itself therefore is not necessary.

Request To Revise Proposed AD Requirements To Apply to All Fuel Tanks

    NATCA noted that action similar to the proposed requirements of the 
NPRM (77 FR 12506, March 1, 2012) was required for all fuel tanks on 
early Model 747 and 737 airplanes via AD 98-20-40, Amendment 39-10808 
(63 FR 52147, September 30, 1998); and AD 99-03-04, Amendment 39-11018 
(64 FR 4959, February 2, 1999). The commenter also noted that the FAA's 
published SFAR 88 unsafe condition criteria (section 25.981(a)(3) of 
the Federal Aviation Regulations (14 CFR 25.981(a)(3)) (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716)) require corrective action for 
``known latent-plus-one conditions'' in both low- and high-flammability 
tanks.
    We infer the commenter is requesting that we revise the proposed 
actions of the NPRM (77 FR 12506, March 1, 2012) to apply to all fuel 
tanks. We disagree. NATCA's interpretation of the word ``known'' 
appears to be different from that intended by the FAA when the SFAR 88 
decision criteria were developed and implemented. For low-flammability 
fuel tanks, the FAA has proposed that corrective action for ``latent-
plus-one'' issues be required only in cases where the particular 
latent-plus-one scenario is known to have occurred on that particular 
design. Where relevant design details are significantly different, a 
condition that has occurred with one design is not considered to be a 
``known'' latent-plus-one condition on another design simply because 
the same architectural vulnerability theoretically exists.
    In the case of AD 98-20-40, Amendment 39-10808 (63 FR 52147, 
September 30, 1998); and AD 99-03-04, Amendment 39-11018 (64 FR 4959, 
February 2, 1999); we required corrective action for all fuel tanks 
because the details of those designs were identical or very similar to 
the details of the design that were considered to be the most likely 
cause of the 1996 Model 747-100 accident. The actions of AD 98-20-40 
and AD 99-03-04 are consistent with the intent of the later-developed 
SFAR 88 unsafe condition criteria. We have not changed this SNPRM 
regarding this issue.

Request for Specific Corrective Action

    EASA noted that the NPRM (77 FR 12506, March 1, 2012) did not cite 
service information for a specific design solution other than 
acknowledging FRM as an acceptable method of compliance. We infer that 
EASA is requesting that the NPRM propose to require a specific 
corrective action for the unsafe condition. EASA pointed out that, 
under its regulations and policies, EASA issues ADs based on specific 
solutions provided by the responsible manufacturer. EASA stated that, 
in the absence of a specific solution, EASA will not be in a position 
to simply adopt the FAA AD, and may need to develop its own AD or find 
another solution.
    We disagree with the request to require a specific corrective 
action in this SNPRM. In this case, the manufacturer has not provided a 
corrective action specific to FQIS in time to support the NPRM, noting 
that they have provided service instructions to install FRM that the 
FAA has defined as one method of compliance within the NPRM (77 FR 
12506, March 1, 2012). While the FAA has the authority to compel the 
manufacturer to provide a solution specifically providing FQIS 
protection, in this case the FAA decided to seek public comment on the 
NPRM (77 FR 12506, March 1, 2012) before deciding whether to take that 
action. The FAA already requires the vast majority of passenger 
airplanes registered in the U.S. to be equipped with FRM, and since we 
defined incorporation of FRM as one method of compliance within the 
NPRM (77 FR 12506, March 1, 2012), and because Boeing and Goodrich 
provided information to show that a specific FQIS protection solution 
would have a per-airplane cost similar to that of Boeing's FRM design 
solution, we have determined there is no practical reason to require 
the manufacturer to provide a corrective action specific to FQIS for 
passenger airplanes. Consideration of the many comments on the NPRM (77 
FR 12506, March 1, 2012) has resulted in a revision of the FAA's 
approach for cargo airplanes, leading to a significantly different 
proposed AD. At this point we do expect the manufacturer to provide 
service information for the proposed optional solution for cargo 
airplanes. We have, however, decided not to further delay action on 
this issue by waiting for that service information. The service 
information is expected to be released shortly after the issuance of a 
final rule.

[[Page 9409]]

No change to this SNPRM is necessary for this issue. If service 
information becomes available before the final rule is issued, we might 
consider incorporating it into the AD.

Request for Information on Modifications

    Icelandair requested more detailed information on the specific 
modifications that would need to be performed to comply with the 
proposed requirements specified in the NPRM (77 FR 12506, March 1, 
2012), and asked if a related service bulletin was available.
    Service information is available for incorporation of FRM approved 
by the FAA as compliant with the FTFR rule (73 FR 42444, July 21, 2008) 
requirements of section 26.33(c)(1) of the Federal Aviation Regulations 
(14 CFR 26.33(c)(1)).
    As stated previously, we have revised the NPRM (77 FR 12506, March 
1, 2012) to provide more specific information about a less costly 
optional modification for cargo airplanes. Service information related 
to this modification is not currently available. We have not changed 
this SNPRM further regarding this issue.

Request for Optional Modification

    Goodrich requested that we revise the NPRM (77 FR 12506, March 1, 
2012) to require or allow a modification to separate and shield the 
FQIS tank-side circuits from other wiring as corrective action for the 
identified unsafe condition. Goodrich referred to its discussion 
regarding the capability of the Goodrich FQIS processor to isolate the 
tank-side circuits from the non-tank-side circuits.
    We partially agree with the request. We considered that method of 
compliance and determined that the benefit from that corrective action 
would be sufficient for cargo airplanes when combined with regular FQIS 
checks using the previously mentioned built-in test capability. We 
disagree with allowing the proposed alternative for passenger airplanes 
that are not equipped with FRM because the level of risk reduction 
achieved from that alternative corrective action would not provide a 
sufficient risk reduction for those airplanes. Even when the built-in 
test capability is periodically exercised, there will still be a 
significant latency period for some in-tank failures. The risk on the 
flights where those failures exist and where flammable conditions exist 
in the fuel tank is considered to be excessive for passenger airplanes, 
because it results from a single additional failure (those flights 
would not be fail-safe). Even if it did not result from an additional 
single failure, it would still exceed the TARAM-allowable risk level 
for individual flight risk. This determination is consistent with the 
SFAR 88 corrective action decision policy and TARAM policy. As 
discussed previously, we have added new paragraph (h) in this SNPRM to 
allow the option of a periodic BITE check and partial wire separation 
for cargo airplanes.

Request for Repetitive Inspections or Replacement

    Oy Air Finland Ltd. stated that wires within the fuel tank must 
remain in an undamaged condition and therefore requested that we revise 
the NPRM (77 FR 12506, March 1, 2012) to specify their repetitive 
inspection or replacement. The commenter provided no justification.
    We disagree with including specific requirements to periodically 
inspect or replace the wiring within the fuel tanks because 
airworthiness limitations and existing maintenance practices are 
already in place to monitor the condition of in-tank wiring. This SNPRM 
would require installation of flammability reduction means or a 
combination of periodic system checks (which would detect many types of 
wiring defects or damage) and wire separation improvements, either of 
which would significantly reduce the probability of a fuel tank 
explosion on a given airplane flight to an acceptable level. We have 
not changed this SNPRM regarding this issue.

Request To Compel Issuance of Service Information

    NATCA requested that we enforce sections 21.99 and 183.63(d) of the 
Federal Aviation Regulations (14 CFR 21.99 and 183.63(d)) and SFAR 88, 
Amendment 21-78, and subsequent Amendments 21-82 and 21-83) (http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgFAR.nsf/0/EEFB3F94451DC06286256C93004F5E07?OpenDocument) to obtain necessary 
service information from design approval holders. NATCA noted that EASA 
cannot ``issue ADs'' (that is, EASA may not be able to adopt the FAA AD 
per se) if specific service information is not identified. NATCA 
expressed concern that other civil aviation authorities may take a 
similar position.
    We partially agree with the request. We agree that the cited 
regulations are relevant in setting requirements for action by design 
approval holders when we have identified an unsafe condition. We also 
recognize that issuance of an AD without service information creates 
significant issues for regulatory agencies and for operators that must 
comply with the AD. This SNPRM, however, is not the appropriate forum 
to discuss potential enforcement action. We have not changed this SNPRM 
regarding this issue.

Boeing's Planned Service Information

    Boeing stated that it will offer only the Boeing FRM as a solution, 
if the AD is issued as proposed. Boeing added that it does not develop 
detailed cost estimates for design changes they do not intend to 
provide. Further, Boeing stated that it does not advocate FRM 
installation on airplanes for which FRM is not required under the FTFR 
rule (``Reduction of Fuel Tank Flammability in Transport Category 
Airplanes'' (73 FR 42444, July 21, 2008)). Boeing proposed no change to 
the NPRM (77 FR 12506, March 1, 2012). Boeing noted that a requirement 
to install an FRM on the affected airplanes could not be justified in 
the cost-versus-benefit analysis performed for the new FTFR rule, and 
therefore cannot be justified to address the unsafe condition 
identified by the FAA.
    We have provided the basis for this SNPRM in response to ``Request 
for Cost-Benefit Analysis'' in this SNPRM. We emphasize, however, that 
this SNPRM does not require installation of a nitrogen generation 
system or other FRM. The actions specified in this SNPRM will correct a 
specific, known unsafe condition with the FQIS. We decided to propose 
this AD action without specific service information for the expected 
design solution specifically because Boeing has not to date provided a 
design solution specific to FQIS. As a result of considering the 
comments to the NPRM (77 FR 12506, March 1, 2012), the FAA has 
identified a less costly option for Model 757 cargo airplanes. We have 
asked Boeing to develop service information for that option, and Boeing 
has agreed. Since the FAA already requires the vast majority of 
passenger airplanes registered in the U.S. to be equipped with FRM and 
we defined incorporation of FRM as one method of compliance within the 
NPRM (77 FR 12506, March 1, 2012), and because Boeing and Goodrich 
provided information to show that a specific FQIS protection solution 
would have a per-airplane cost similar to that of Boeing's FRM design 
solution, we have determined there is no practical reason to require 
the manufacturer to provide a corrective action specific to FQIS for 
passenger airplanes. We have not further changed this SNPRM regarding 
this issue.

[[Page 9410]]

Request To Extend Compliance Time Pending Issuance of Service 
Information

    A4A requested that we revise the NPRM (77 FR 12506, March 1, 2012) 
to extend the compliance time from 60 months to ``a 96-month compliance 
period that commences one year after the effective date of the AD''--
for a total compliance time of 9 years. A4A noted that SFAR 88 (Special 
Federal Aviation Regulation No. 88 (``SFAR 88,'' Amendment 21-78, and 
subsequent Amendments 21-82 and 21-83) (http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgFAR.nsf/0/EEFB3F94451DC06286256C93004F5E07?OpenDocument)) required design 
solutions for non-compliant designs to be provided by December 6, 2002, 
and considered that the absence of service information reflects a 
failure of communication and coordination, presumably between the FAA 
and Boeing. A4A was concerned that Boeing's declaration that it does 
not intend to develop a design solution other than its existing 
nitrogen generation system indicates that the development of any other 
design solution would be technically challenging and time consuming. 
A4A also cited the implementation of the requirements of part 26 of the 
Federal Aviation Regulations (14 CFR part 26) as an example of the FAA 
underestimating the costs and time required to develop design 
solutions.
    We partially agree with the request to extend the compliance time. 
While we agree to provide additional time for manufacturers to develop 
service information, we acknowledge that service information is not 
likely to be available until several months after the final rule is 
issued. We disagree with the assertion that the delay in proposing an 
AD to address the FQIS latent-plus-one unsafe conditions on several 
transport airplane models reflects a failure to communicate and 
coordinate with design approval holders.
    In 2003, the FAA held a series of AD board meetings to decide which 
of the design areas identified in SFAR 88 design reviews as non-
compliant on Boeing airplanes would be classified as unsafe conditions 
requiring AD action. The FQIS latent-plus-one issue was identified as 
an unsafe condition for high flammability fuel tanks at that time for 
several models, including the Model 757. Several airplane models from 
other manufacturers were identified as having similar issues. However, 
during that same time period, the National Transportation Safety Board 
(NTSB) had recommended FAA action to require inerting systems for 
center fuel tanks, and the FAA was working with industry to develop a 
practical nitrogen generation system for new production and retrofit 
installations on transport airplanes. The FAA was also planning to 
propose a new rule requiring those systems to be installed on new and 
existing airplanes, as recommended by the NTSB. The FAA recognized 
that, if such a system was installed on a given set of airplanes, the 
unsafe condition determination for the center fuel tank latent-plus-one 
would be addressed due to the modified center fuel tank meeting the 
conditions for a low flammability fuel tank after installation of a 
nitrogen generation system.
    The FAA therefore decided to defer addressing the FQIS latent-plus-
one issue on the affected airplanes until after the outcome of the FTFR 
rulemaking process. Now that the rulemaking process is complete and the 
safety enhancement provided by the FTFR rule (73 FR 42444, July 21, 
2008) has been limited to certain airplanes (14 CFR part 121, 125, and 
129 passenger airplanes), the FAA is addressing the FQIS latent-plus-
one unsafe conditions on the airplanes that are not required to receive 
the safety enhancement of the FTFR rule. This history was discussed in 
detail in the NPRM (77 FR 12506, March 1, 2012) and in the preamble for 
the FTFR rule.
    We disagree with extending the compliance time to 9 years. Service 
information to support the modification portion of the option for cargo 
airplanes is expected to be available shortly after the final rule is 
issued. The service information for the inspection portion of that 
option and the FRM option is already released. We have determined that 
a compliance time extension to 72 months for the modification will give 
adequate time for manufacturers to complete the remaining service 
information and for operators to complete the modification.
    We have revised the compliance time in this SNPRM to 72 months 
after the effective date of the AD.

Request To Reduce Compliance Time

    NATCA requested that we reduce the compliance time from 60 months 
to 36 months because of the time that has already passed to address 
this unsafe condition since its identification in 2003.
    While we acknowledge the time that has passed since the 
identification of the unsafe condition identified in this SNPRM, the 
FAA delayed taking action for this issue while we developed the FTFR 
rule (73 FR 42444, July 21, 2008), determined its applicability, which 
directly affected the applicability of this SNPRM, and implemented the 
FTFR rule. Now that we are proposing action for the affected airplanes, 
we must consider the ability of industry to develop an appropriate 
design change and incorporate it on all affected airplanes; we find 
that it is not practical for industry to respond to this AD in only 3 
years. We have therefore not reduced the compliance time in this SNPRM.

Request To Revise Cost Estimate Based on New Data

    Boeing requested that we revise the cost estimate specified in the 
NPRM (77 FR 12506, March 1, 2012) because the actual cost to develop 
and implement a design change to fully address the FQIS latent-plus-one 
failure conditions would be significantly higher. Boeing estimated in 
their comment that the cost to develop and implement a transient 
suppression unit design for Model 757 airplanes would be about the same 
as the cost of Boeing's FRM provided for the airplanes affected by the 
FTFR rule (73 FR 42444, July 21, 2008): in excess of $300,000 per 
airplane for airplanes equipped with the early FQIS design, and in 
excess of $200,000 per airplane for airplanes equipped with a Goodrich 
FQIS.
    In a subsequent meeting initiated by the FAA to obtain more detail 
on this cost estimate, Boeing provided a higher cost estimate than they 
provided in their written comment. However, in subsequent discussions 
with Boeing as part of developing this SNPRM, Boeing indicated that 
they were working on an isolation-based design alternative to the FAA's 
proposed modification option for the cargo airplanes that would likely 
be significantly less costly than the FAA's proposed cargo airplane 
option of partial wire separation.
    We partially agree with the commenter. We agree to revise the cost 
estimate because both Boeing and one of Boeing's affected FQIS vendors 
provided similar cost estimates that were higher than the estimates 
made in the NPRM (77 FR 12506, March 1, 2012) by the FAA. We disagree 
to revise the cost estimate as Boeing proposed. We have received 
several inconsistent cost estimates from industry during the 
development of the FTFR rule (73 FR 42444, July 21, 2008), in their 
written comments to the NPRM, and during discussions of the FAA's 
proposed alternative for cargo airplanes. We have therefore provided a 
revised cost estimate for the originally proposed action based on input 
from Boeing's written comment and from the FQIS vendor. We also have 
considered that it

[[Page 9411]]

is likely that aftermarket vendors may develop competing design 
solutions, as has occurred for other similar ADs, and those solutions 
will likely cost less than the original manufacturer's solutions.
    In addition, we have identified an additional compliance option--
with a different cost--for cargo airplanes. That cost estimate is based 
on Model 757 service information that described a very similar 
modification. We have used the work-hour estimate from that service 
bulletin, increased the work-hour estimate by 20 percent to account for 
any unforeseen increases in the work, and increased the parts prices to 
account for inflation and the potential that additional parts may be 
needed.

Request To Revise Cost Estimate Based on AD Scope

    Goodrich requested that, if the intent of the NPRM (77 FR 12506, 
March 1, 2012) is to protect all fuel tanks rather than just the center 
fuel tank, we revise the cost estimate of the NPRM accordingly. 
Goodrich stated that the cost estimate is based on three assumptions: 
(1) That current technology circuit isolation devices similar to those 
previously approved for other models would be acceptable, (2) that no 
further changes to airplane wiring would be required, and (3) that the 
design change would be required to protect only the center fuel tank. 
Goodrich noted that protection for all fuel tanks is required for the 
two similar ADs: AD 99-03-04, Amendment 39-11018 (64 FR 4959, February 
2, 1999), for Model 737 airplanes; and AD 98-20-40, Amendment 39-10808 
(63 FR 52147, September 30, 1998), for Model 747 airplanes. Goodrich 
requested that we revise the cost estimate if the AD's intent is to 
require protection for fuel tanks other than the center fuel tank or if 
other wiring change requirements are anticipated. Goodrich stated that 
the cost specified in the NPRM should be estimated based on the actual 
design changes expected, rather than on previous AD actions.
    We provide the following clarification of the intended scope of the 
NPRM (77 FR 12506, March 1, 2012) and the associated cost estimate 
regarding which fuel tanks are subject to the proposed requirements. AD 
99-03-04, Amendment 39-11018 (64 FR 4959, February 2, 1999), and AD 98-
20-40, Amendment 39-10808 (63 FR 52147, September 30, 1998), affect 
FQIS designs that are considered to have a higher level of risk of a 
fuel tank ignition source than the systems used on Model 757 airplanes. 
In addition, those systems were identical or nearly identical to the 
FQIS that was determined by the NTSB to be the most likely cause of the 
1996 Model 747-100 accident described in the NPRM. Because the latent-
plus-one failure scenario was suspected of actually having occurred on 
that system type, we determined that corrective action for all fuel 
tanks was appropriate. This decision was consistent with the 
subsequently published FAA policy on SFAR 88 AD decision criteria 
(section 25.981(a)(3) of the Federal Aviation Regulations (14 CFR 
25.981(a)(3))) (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716)). Also, it was our understanding that the design of that FQIS 
was such that, due to wiring interconnections between fuel tanks, it 
was necessary to protect the circuits for all fuel tanks in order to 
achieve effective protection for any one fuel tank.
    We have determined that the FQIS used on earlier production Model 
757 airplanes has the same fuel tank interconnection issue, but that 
the Goodrich system used on later production Model 757 airplanes does 
not have that issue. Since the cost estimates provided by both Boeing 
and Goodrich were based on design solutions that included upgrading to 
a Goodrich FQIS, we assume that the level of circuit protection for the 
center fuel tank can be significantly increased relative to the 
existing Goodrich design without having to further alter circuits or 
wiring for the main fuel tanks (beyond the alterations necessary to 
replace the FQIS with the Goodrich FQIS).
    Because the latent-plus-one scenarios for Model 757 airplanes 
equipped with the Goodrich FQIS are classified as ``theoretical'' 
rather than ``known to have occurred'' under the FAA policy on SFAR 88 
AD decision criteria (section 25.981(a)(3) of the Federal Aviation 
Regulations (14 CFR 25.981(a)(3))) (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73716)), we have determined in 
accordance with that policy that the corrective action for passenger 
airplanes must eliminate the potential for all theoretical latent-plus-
one scenarios to create an ignition source in the center fuel tank, 
which is classified under that policy as a high flammability fuel tank. 
The need to modify the circuits or wiring for the main fuel tanks to 
achieve that intent will depend on the proposed design solution and the 
existing configuration of the airplane.
    As stated previously, we have revised the cost estimate in this 
SNPRM. For the purpose of the cost estimate for passenger airplanes, we 
have assumed that the airplane will be upgraded to the Goodrich FQIS if 
necessary, and any further modifications will be to only the center 
fuel tank circuits or wiring. For the purpose of the additional 
proposed cargo airplane option, we have provided separate estimates for 
each design. For cargo airplanes equipped with the early 757 FQIS 
design, we have assumed that additional isolation of some main fuel 
tank wiring will be required. It is not necessary to change the 
proposed requirement itself in paragraph (g) of this SNPRM, which is 
very specific that protection is required for the center fuel tank.

Request To Revise Cost Estimate To Consider Long-Term Effect of AD

    Goodrich asked whether the cost estimate specified in the NPRM (77 
FR 12506, March 1, 2012) considers the expectation that the affected 
fleet will be in operation for at least 20 more years, and that a 
complete redesign of the FQIS would need to be considered to ensure the 
availability of key FQIS electrical components. Goodrich stated this 
concern could drive potential development costs higher.
    We agree with the commenter's assertion. We did consider that the 
affected fleet will be in service for a considerable period of time. In 
the cost estimate in the NPRM (77 FR 12506, March 1, 2012), we assumed 
that the existing FQIS could be modified to meet the intent of the AD. 
However, comments from Boeing and Goodrich led us to recognize that it 
was likely that operators of airplanes with the early 757 FQIS design 
will likely need to be upgraded to the later Goodrich FQIS. The cost 
estimates used in this SNPRM for the fully compliant FQIS option (as 
opposed to the newly added cargo airplane option) are based on the 
estimates provided by Boeing and Goodrich. We previously described 
changes to the cost estimate in this SNPRM, but no further change is 
necessary regarding this issue.

Request To Explain Delay in Rulemaking and Identify Planned SFAR 88 ADs

    A4A requested that we explain the delay in rulemaking for this 
issue, and identify any further planned SFAR 88 ADs. A4A asked why the 
NPRM (77 FR 12506, March 1, 2012) was issued approximately 10 years 
after the identification of the unsafe conditions and development of 
design solutions was required to be completed under SFAR 88. A4A 
further asked that the FAA provide information on any other

[[Page 9412]]

designs that were already reviewed under SFAR 88, and provide industry 
with information regarding their planned disposition.
    We have specifically discussed these issues in the preamble to the 
FTFR rule (73 FR 42444, July 21, 2008) and the NPRM (77 FR 12506, March 
1, 2012), and explained the reasons for the delay in the response to 
``Request to Extend Compliance Time Pending Issuance of Service 
Information'' in this SNPRM. We cannot provide additional information 
on the results of design reviews and the planned disposition of issues 
identified in those design reviews because that information is 
proprietary. The FAA has not made available to the public an overall 
list of the specific product issues identified and the plans to address 
those issues, but operators can request the design review results from 
the manufacturers. We will likely propose additional AD rulemaking, and 
the public will be notified of those proposals via NPRMs. We have not 
changed this SNPRM regarding this issue.

Request To Explain Timing of NPRM (77 FR 12506, March 1, 2012) and 
Deficiencies of Affected Design

    FedEx requested that we explain what is non-compliant about the 
affected design and why we are proposing this design change at this 
late date. FedEx stated that Boeing and Goodrich determined in their 
safety reviews that only the FQIS densitometer was non-compliant.
    We agree to provide further explanation. This SNPRM addresses the 
question about the timing of this proposal under ``Request to Extend 
Compliance Time Pending Issuance of Service Information'' in this 
SNPRM. Boeing and Goodrich did identify that the densitometer of the 
Goodrich system had the potential for a single failure to cause an 
ignition source in a fuel tank. That issue was addressed by AD 2009-06-
20, Amendment 39-15857 (74 FR 12236, March 24, 2009). However, the 
Boeing safety review and the FAA SFAR 88 AD Board also identified the 
potential for a failure in airplane wiring outside the fuel tank or in 
the FQIS processor unit that, combined with a pre-existing latent 
failure of wiring or certain types of probe contamination inside the 
fuel tank, could cause an ignition source. These identified failure 
combinations were considered to be non-compliant with section 25.901(c) 
of the Federal Aviation Regulations (14 CFR 25.901(c)) and section 
25.981 of the Federal Aviation Regulations (14 CFR 25.981). We have not 
changed this SNPRM regarding this issue.

Request for Independent Review Regarding Timeliness of AD

    NATCA requested an independent review to identify and document how 
this issue was allowed to go unaddressed for 16 years since the TWA 
accident and 9 years since SFAR 88 required the development of service 
information. The commenter requested that the findings from that review 
be published.
    We acknowledge that there have been significant delays in 
addressing the issue that is the subject of this SNPRM. We are also 
fully aware of the events and factors that have led to those delays. We 
infer that NATCA made the request to ensure that the public is aware of 
those events and factors. We have described those events and factors in 
the NPRM (77 FR 12506, March 1, 2012) and in the other comment 
responses included in this SNPRM, and therefore the FAA does not plan 
to conduct the proposed review. We have not changed this SNPRM 
regarding this issue.

Request To Clarify Compliance Times

    A4A requested that we revise the NPRM (77 FR 12506, March 1, 2012) 
to clarify that the compliance deadlines in the AD prevail over the 
compliance deadlines in section 121.1117 of the Federal Aviation 
Regulations (14 CFR 121.1117) for any airplane for which the operator 
has chosen to comply with the AD by installing FRM.
    The proposed compliance times reflect the desired interpretation of 
the commenter as they pertain to cargo airplanes and airplanes that are 
not operated per part 121, part 125, or part 129 of the Federal 
Aviation Regulations (14 CFR part 121, 14 CFR part 125, or 14 CFR part 
129). Passenger airplanes operating under part 121, part 125, or part 
129 of the Federal Aviation Regulations (14 CFR part 121, 14 CFR part 
125, or 14 CFR part 129) must meet the compliance deadlines established 
in those operating rules. No change to this SNPRM is necessary 
regarding this issue.

Request To Clarify Master Minimum Equipment List (MMEL) Relief

    A4A requested that we revise the NPRM (77 FR 12506, March 1, 2012) 
to clarify that the MMEL relief provided for the Boeing NGS also 
applies to airplanes for which the operator has chosen to comply with 
the AD by installing an FRM such as the Boeing NGS.
    We acknowledge the commenter's concern. The revised applicability 
statement in paragraph (c) of this SNPRM excludes airplanes that are 
``equipped with a flammability reduction means (FRM) approved by the 
FAA. . . .'' That exclusion does not state that the installed equipment 
must be operative. However, installed equipment is required to be 
operative by sections 121.628, 125.201, and 129.14 of the Federal 
Aviation Regulations (14 CFR 121.628, 14 CFR 125.201, and 14 CFR 
129.14) except as allowed by the MMEL and the operator's approved 
minimum equipment list (MEL). Dispatch with an inoperative FRM under 
the MMEL is not prohibited by the AD, and our intent is to allow such 
operation. We have not further changed this SNPRM regarding this issue.

Request To Clarify Airplanes Excluded From Applicability

    A4A requested that we revise the NPRM (77 FR 12506, March 1, 2012) 
to clarify that airplanes equipped with FRM before conversion to all-
cargo operations are excluded from the proposed requirement to modify 
the FQIS.
    We agree to provide clarification. The revised applicability of 
this SNPRM excludes airplanes for which operators have installed FRM. 
No further change is necessary to this SNPRM regarding this issue. As 
noted above, the FRM must be operational with the exception of any 
relief granted under MMEL provisions.

Additional Change to NPRM (77 FR 12506, March 1, 2012)

    We have removed NOTE 1 of the NPRM (77 FR 12506, March 1, 2012). 
The note was included only as reminder that maintenance and/or 
preventive maintenance under 14 CFR part 43 is permitted provided the 
maintenance does not result in changing the AD-mandated configuration 
(reference 14 CFR 39.7).

FAA's Determination

    We are proposing this SNPRM because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design. 
Certain changes described above expand the scope of the NPRM (77 FR 
12506, March 1, 2012). As a result, we have determined that it is 
necessary to reopen the comment period to provide additional 
opportunity for the public to comment on this SNPRM.

Proposed Requirements of the SNPRM

    This SNPRM would require modifying the FQIS wiring or fuel tank 
systems to prevent development of an ignition source inside the center 
fuel tank.

[[Page 9413]]

Costs of Compliance

    We estimate that this proposed AD affects 167 airplanes of U.S. 
registry. This estimate includes 148 cargo airplanes and 19 non-air-
carrier passenger airplanes. We estimate the following costs to comply 
with this proposed AD:

----------------------------------------------------------------------------------------------------------------
                Action                            Labor cost              Parts cost        Cost per product
----------------------------------------------------------------------------------------------------------------
                          Estimated Costs--Basic Proposed Requirement for All Airplanes
----------------------------------------------------------------------------------------------------------------
Fully correct FQIS vulnerability to     1,200 work-hours x $85 per            $200,000  $302,000.
 latent-plus-one failure conditions.     hour = $102,000.
----------------------------------------------------------------------------------------------------------------
                               Estimated Costs--Optional Actions for All Airplanes
----------------------------------------------------------------------------------------------------------------
Install FRM...........................  720 work-hours x $85 per hour         $323,000  $384,200.
                                         = $61,200.
----------------------------------------------------------------------------------------------------------------
                              Estimated Costs--Optional Actions for Cargo Airplanes
----------------------------------------------------------------------------------------------------------------
Wire separation.......................  230 work-hours x $85 per hour          $10,000  $29,550.
                                         = $19,550.
FQIS BITE check (required with wire     1 work-hour x $85 per hour =                 0  $85 per check (4 checks
 separation option).                     $85.                                            per year).
----------------------------------------------------------------------------------------------------------------

    Existing regulations already require that air-carrier passenger 
airplanes be equipped with FRM by December 26, 2017. We therefore 
assume that the FRM installation specified in paragraph (g) of this 
SNPRM would be done on only the 19 affected non-air-carrier passenger 
airplanes, for an estimated passenger fleet cost of $5,738,000. We also 
assume that the operators of the 148 affected cargo airplanes would 
choose the less costly actions specified in paragraph (h) of this AD, 
at an estimated cost of $4,373,400 for the wire separation 
modification, plus $50,320 annually for the BITE checks.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation Programs'' 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

The Boeing Company: Docket No. FAA-2012-0187; Directorate Identifier 
2011-NM-094-AD.

(a) Comments Due Date

    We must receive comments by April 24, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 757-200, -200PF, -
200CB, and -300 series airplanes; certificated in any category; 
except airplanes equipped with a flammability reduction means (FRM) 
approved by the FAA as compliant with the Fuel Tank Flammability 
Reduction (FTFR) rule (73 FR 42444, July 21, 2008) requirements of 
section 25.981(b) or section 26.33(c)(1) of the Federal Aviation 
Regulations (14 CFR 25.981(b) or 14 CFR 26.33(c)(1)).

(d) Subject

    Joint Aircraft System Component (JASC) Code 7397: Engine fuel 
system wiring.

(e) Unsafe Condition

    This AD was prompted by fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent development of an 
ignition source inside the center fuel tank caused by a latent in-
tank failure combined with electrical energy transmitted into the 
center fuel tank via the fuel quantity indicating system (FQIS) 
wiring due to a single out-tank failure.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Modification

    Within 72 months after the effective date of this AD, modify the 
FQIS wiring or fuel tank systems to prevent development of an 
ignition source inside the center fuel tank, using a method approved 
in accordance with the procedures specified in paragraph (i) of this 
AD.

(h) Optional Actions for Cargo Airplanes

    For airplanes used exclusively for cargo operations: As an 
option to the requirements of paragraph (g) of this AD, do the 
actions

[[Page 9414]]

specified in paragraphs (h)(1) and (h)(2) of this AD, using methods 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.
    (1) Within 6 months after the effective date of this AD, record 
the existing fault codes stored in the FQIS processor and then do a 
BITE check (check of built-in test equipment) of the FQIS, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 757-28-0136, dated June 5, 2014. If any fault codes are 
recorded prior to the BITE check or as a result of the BITE check, 
before further flight, do all applicable repairs and repeat the BITE 
check until a successful test is performed with no faults found, in 
accordance with Boeing Service Bulletin 757-28-0136, dated June 5, 
2014. Repeat these actions thereafter at intervals not to exceed 750 
flight hours.
    (2) Within 72 months after the effective date of this AD, modify 
the airplane by separating FQIS wiring that runs between the FQIS 
processor and the center fuel tank, including any circuits that 
might pass through a main fuel tank, from other airplane wiring that 
is not intrinsically safe.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in paragraph (j) of this AD. 
Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    For more information about this AD, contact Jon Regimbal, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle 
Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; phone: 425-917-6506; fax: 425-917-6590; 
email: [email protected].

    Issued in Renton, Washington, on December 18, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-03540 Filed 2-20-15; 8:45 am]
BILLING CODE 4910-13-P



                                                 9400                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 SUPPLEMENTARY INFORMATION:     On                       manufacturer. This action revises the                 except Federal holidays. The AD docket
                                                 December 19, 2014, DOE published in                     NPRM by revising the applicability,                   contains this proposed AD, the
                                                 the Federal Register a notice of                        including optional actions for cargo                  regulatory evaluation, any comments
                                                 proposed rulemaking (NOPR) to update                    airplanes, and extending the compliance               received, and other information. The
                                                 the energy conservation standards for                   time. We are proposing this                           street address for the Docket Office
                                                 residential dishwashers. 79 FR 76142 .                  supplemental NPRM (SNPRM) to                          (phone: 800–647–5527) is in the
                                                 In the NOPR, DOE invited written                        prevent ignition sources inside the                   ADDRESSES section. Comments will be
                                                 submission of public comments, to be                    center fuel tank, which, in combination               available in the AD docket shortly after
                                                 received by February 17, 2015. On an                    with flammable fuel vapors, could result              receipt.
                                                 email dated January 16, 2015, the                       in fuel tank explosions and consequent                FOR FURTHER INFORMATION CONTACT: Jon
                                                 Association for Home Appliance                          loss of the airplane. Since these actions             Regimbal, Aerospace Engineer,
                                                 Manufacturers (AHAM) requested an                       significantly change the corrective                   Propulsion Branch, ANM–140S, FAA,
                                                 extension of the public comment period                  action options for cargo airplanes                    Seattle Aircraft Certification Office
                                                 by 60 days. AHAM stated in its request                  relative to the proposal in the NPRM,                 (ACO), 1601 Lind Avenue SW., Renton,
                                                 that AHAM required additional time to                   and because the cost estimate is                      WA 98057–3356; phone: 425–917–6506;
                                                 review the published analysis in order                  significantly revised, we are reopening               fax: 425–917–6590; email:
                                                 to prepare and submit comments                          the comment period to allow the public                jon.regimbal@faa.gov.
                                                 accordingly. DOE has determined that                    the chance to comment on these
                                                                                                                                                               SUPPLEMENTARY INFORMATION:
                                                 extending the comment period to allow                   proposed changes.
                                                 additional time for interested parties to               DATES: We must receive comments on                    Comments Invited
                                                 submit comments is appropriate based                    this SNPRM by April 24, 2015.                           We invite you to send any written
                                                 on the foregoing reason. DOE believes                   ADDRESSES: You may send comments,                     relevant data, views, or arguments about
                                                 an additional 30-days, providing a total                using the procedures found in 14 CFR                  this proposed AD. Send your comments
                                                 comment period of 90 days, allows                       11.43 and 11.45, by any of the following              to an address listed under the
                                                 sufficient time for submitting inputs                   methods:                                              ADDRESSES section. Include ‘‘Docket No.
                                                 regarding DOE’s analysis. Accordingly,                    • Federal eRulemaking Portal: Go to                 FAA–2012–0187; Directorate Identifier
                                                 DOE will consider any comments                          http://www.regulations.gov. Follow the                2011–NM–094–AD’’ at the beginning of
                                                 received by midnight of March 25, 2015,                 instructions for submitting comments.                 your comments. We specifically invite
                                                 and deems any comments received by                        • Fax: 202–493–2251.                                comments on the overall regulatory,
                                                 that time to be timely submitted.                         • Mail: U.S. Department of                          economic, environmental, and energy
                                                   Issued in Washington, DC, on February 12,             Transportation, Docket Operations, M–                 aspects of this proposed AD. We will
                                                 2015.                                                   30, West Building Ground Floor, Room                  consider all comments received by the
                                                 Kathleen B. Hogan,                                      W12–140, 1200 New Jersey Avenue SE.,                  closing date and may amend this
                                                 Deputy Assistant Secretary for Energy                   Washington, DC 20590.                                 proposed AD because of those
                                                 Efficiency, Energy Efficiency and Renewable               • Hand Delivery: U.S. Department of                 comments.
                                                 Energy.                                                 Transportation, Docket Operations, M–                   We will post all comments we
                                                 [FR Doc. 2015–03599 Filed 2–20–15; 8:45 am]             30, West Building Ground Floor, Room                  receive, without change, to http://
                                                 BILLING CODE 6450–01–P                                  W12–140, 1200 New Jersey Avenue SE.,                  www.regulations.gov, including any
                                                                                                         Washington, DC 20590, between 9 a.m.                  personal information you provide. We
                                                                                                         and 5 p.m., Monday through Friday,                    will also post a report summarizing each
                                                 DEPARTMENT OF TRANSPORTATION                            except Federal holidays.                              substantive verbal contact we receive
                                                                                                           For service information identified in               about this proposed AD.
                                                 Federal Aviation Administration                         this AD, contact Boeing Commercial
                                                                                                         Airplanes, Attention: Data & Services                 Discussion
                                                 14 CFR Part 39                                          Management, P. O. Box 3707, MC 2H–                      We issued an NPRM to amend 14 CFR
                                                 [Docket No. FAA–2012–0187; Directorate
                                                                                                         65, Seattle, WA 98124–2207; telephone                 part 39 by adding an AD that would
                                                 Identifier 2011–NM–094–AD]                              206–544–5000, extension 1; fax 206–                   apply to certain The Boeing Company
                                                                                                         766–5680; Internet https://                           Model 757 airplanes. The NPRM
                                                 RIN 2120–AA64                                           www.myboeingfleet.com. You may view                   published in the Federal Register on
                                                                                                         this referenced service information at                March 1, 2012 (77 FR 12506). The
                                                 Airworthiness Directives; the Boeing                    the FAA, Transport Airplane                           NPRM proposed to require modifying
                                                 Company Airplanes                                       Directorate, 1601 Lind Avenue SW.,                    the fuel quantity indication system
                                                 AGENCY:  Federal Aviation                               Renton, WA. For information on the                    (FQIS) wiring or fuel tank systems to
                                                 Administration (FAA), DOT.                              availability of this material at the FAA,             prevent development of an ignition
                                                 ACTION: Supplemental notice of                          call 425–227–1221. It is also available               source inside the center fuel tank. We
                                                 proposed rulemaking (NPRM);                             on the Internet at http://                            subsequently issued an NPRM (77 FR
                                                 reopening of comment period.                            www.regulations.gov by searching for                  33129, June 5, 2012) to reopen and
                                                                                                         and locating Docket No. FAA–2012–                     extend the comment period for an
                                                 SUMMARY:   We are revising an earlier                   0187.                                                 additional 2 months.
                                                 proposed airworthiness directive (AD)
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                                                 for certain The Boeing Company Model                    Examining the AD Docket                               Related Service Information Under 1
                                                 757 airplanes. The NPRM proposed to                       You may examine the AD docket on                    CFR Part 51
                                                 require modifying the fuel quantity                     the Internet at http://                                 We have reviewed Boeing Service
                                                 indication system (FQIS) wiring or fuel                 www.regulations.gov by searching for                  Bulletin 757–28–0136, dated June 5,
                                                 tank systems to prevent development of                  and locating Docket No. FAA–2012–                     2014. This service information describes
                                                 an ignition source inside the center fuel               0187; or in person at the Docket                      procedures for the built-in test
                                                 tank. The NPRM was prompted by fuel                     Management Facility between 9 a.m.                    equipment test/procedure (BITE check)
                                                 system reviews conducted by the                         and 5 p.m., Monday through Friday,                    specified in paragraph (h)(1) of this


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                                                                       Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                             9401

                                                 supplemental NPRM. For information                      flight safety risk in consideration of pre-           rgl.faa.gov/Regulatory_and_Guidance_
                                                 on the procedures and compliance                        existing hidden failure conditions and                Library%5CrgFAR.nsf/0/EEFB3F94451
                                                 times, refer to this service information.               accounts for dispatch with inoperative                DC06286256C93004F5E07?Open
                                                 This service information is reasonably                  equipment. The TARAM policy                           Document) and the flammability
                                                 available; see ADDRESSES for ways to                    classifies a flight dispatch condition as             analysis submitted to support
                                                 access this service information.                        ‘‘reasonably anticipated’’ if, in absence             certification of Boeing’s flammability
                                                                                                         of corrective action, ten or more flights             reduction means (FRM), which Boeing
                                                 Comments
                                                                                                         are expected to occur.                                refers to as a nitrogen generation system
                                                   We gave the public the opportunity to                    Average risk is an arithmetic average              (NGS). For those reasonably anticipated
                                                 comment on the NPRM (77 FR 12506,                       of the risk of a given event during all               flights, the probability of a catastrophic
                                                 March 1, 2012). The following presents                  operation of an aircraft fleet, regardless            event (or individual flight safety risk) is
                                                 the comments received on the NPRM                       of whether the risk actually varies                   the probability of an additional single
                                                 and the FAA’s response to each                          during the operation of the fleet. We use             failure in the related aircraft wiring or
                                                 comment.                                                average risk analysis to assess whether               equipment sending a high energy signal
                                                 Request To Withdraw NPRM (77 FR                         a risk is acceptable when there is little             onto the already compromised in-tank
                                                 12506, March 1, 2012): Unjustified by                   or no variation in risk from flight to                circuit(s). The individual flight safety
                                                 Risk                                                    flight. Total fleet risk is the aggregate             risk of a catastrophic event on these
                                                                                                         sum of all risk throughout a fleet during             flights is in excess of the FAA’s
                                                    Boeing and Airbus requested that we                  the remaining fleet life. Total fleet risk            threshold for an unsafe condition
                                                 withdraw the NPRM (77 FR 12506,                         analysis is meaningful in assessing total             determination contained in the
                                                 March 1, 2012). Airbus requested that                   societal risk, but it does not assess the             published TARAM Policy Statement
                                                 we consider risk levels before pursuing                 variation in risk between flights or the              PS–ANM–25–05 (http://rgl.faa.gov/
                                                 anticipated ADs for similar models.                     risk on the worst anticipated flights.                Regulatory_and_Guidance_Library/
                                                 Boeing’s request was based on a                         Individual flight risk as used by the                 rgPolicy.nsf/0/4E5AE870716467
                                                 determination that the risk posed by the                FAA is an assessment of the specific                  4A862579510061F96B?Open
                                                 FQIS is not high enough to warrant AD                   safety risk that exists or will exist on the          Document&Highlight=ps-anm-25-05).
                                                 action. Boeing described the detailed                   worst reasonably anticipated individual                  As discussed above, this risk of a
                                                 design features that it considers make                  flights due to a given issue.                         catastrophic event on those flights is
                                                 the failures contributing to the unsafe                    Individual risk analysis is used by the            due to a single additional failure
                                                 condition unlikely. Boeing added that                   FAA to determine whether the public’s                 condition. The risk on those flights due
                                                 its own numerical probability analysis                  expectation for a reasonable level of                 to a single failure violates the FAA’s
                                                 of the average risk level due to the                    safety on each transport airplane flight              general fail-safe design requirements
                                                 combination of failures required to                     is met. An acceptable average risk level              philosophy for transport airplanes. In
                                                 cause a fuel tank explosion is on the                   and acceptable total fleet risk do not                general, we issue ADs in cases where
                                                 order of one catastrophic event per                     ensure that all reasonably anticipated                reasonably anticipated flights with pre-
                                                 billion flight hours. Boeing pointed out                flights (flights with known inoperative               existing failures (either due to latent
                                                 that this probability level would meet                  equipment, flights with undetected                    failure conditions or allowable dispatch
                                                 the certification standard for systems                  failures, flights in less-than-ideal but              configurations) are vulnerable to a
                                                 contained in section 25.1309(b) of the                  approved and expected weather or                      catastrophic event due to an additional
                                                 Federal Aviation Regulations (14 CFR                    operational conditions, etc.) will                    foreseeable single failure condition.
                                                 25.1309(b)). Boeing also pointed out                    provide the minimum level of safety                   This is because the FAA considers
                                                 that, because the Model 757 is out of                   expected by the public. When the safety               operation of flights vulnerable to a
                                                 production and has a limited remaining                  risk is concentrated on flights with a                potentially catastrophic single failure
                                                 fleet life, the total risk of a catastrophic            given pre-existing dispatch condition or              condition to be an excessive safety risk
                                                 event occurring in the remaining fleet                  expected operational condition, it is                 to the passengers on those flights. This
                                                 life is approximately 0.5 percent. Boeing               possible to have an unacceptable                      SNPRM is consistent with that
                                                 also noted that if a conductive condition               individual flight safety risk on the worst            continued operational safety
                                                 were to exist between the probes or                     reasonably anticipated flights even                   philosophy.
                                                 wiring and structure, it would be                       when the average risk and total fleet risk               In its comment, Boeing stated that the
                                                 identified by FQIS faults and therefore                 are acceptable.                                       existing design meets the numerical
                                                 would not be latent for multiple flights.                  In the case of this SNPRM, the risk                probability requirements of section
                                                    We disagree with the request to                      due to the current Model 757 FQIS                     25.1309(b) of the Federal Aviation
                                                 withdraw the NPRM (77 FR 12506,                         design architecture is not spread equally             Regulations (14 CFR 25.1309(b)), which
                                                 March 1, 2012). Average risk per flight                 among all of the flights conducted on                 requires safety analysis of systems.
                                                 hour and total fleet risk were not the                  the affected airplanes. Instead, the risk             Boeing concluded that the existing
                                                 safety criteria that drove the FAA to                   is concentrated almost entirely on the                system would need no further risk
                                                 propose the AD. In addition to                          small subset of flights that occur with a             reduction to meet the requirements of
                                                 examining average risk and total fleet                  latent failure condition pre-existing in              that rule. We disagree with this
                                                 risk, the FAA examines the individual                   the fuel tank. Flights with such a latent             conclusion. First, the existence of a
                                                 flight risk on the worst reasonably                     failure condition and flammable                       general safety standard, even if met by
                                                 anticipated flights. FAA Transport                      conditions in the center fuel tank have               a design, does not in and of itself
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                                                 Airplane Risk Assessment Methodology                    been judged by the FAA to be                          preclude a determination that there is a
                                                 (TARAM) Policy Statement PS–ANM–                        reasonably anticipated to occur based                 specific unsafe condition. The
                                                 25–05 (http://rgl.faa.gov/                              on the numerical probability analysis                 recognition that compliance with an
                                                 Regulatory_and_Guidance_Library/                        submitted by the manufacturer in                      existing regulation may not be sufficient
                                                 rgPolicy.nsf/0/4E5AE870716467                           response to Special Federal Aviation                  to ensure safety is specifically addressed
                                                 4A862579510061F96B?Open                                 Regulation No. 88 (‘‘SFAR 88,’’                       in type certification by section
                                                 Document&Highlight=ps-anm-25–05)                        Amendment 21–78, and subsequent                       21.21(b)(2) of the Federal Aviation
                                                 calls for the FAA to assess individual                  Amendments 21–82 and 21–83) (http://                  Regulations (14 CFR 21.21.(b)(2)) and


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                                                 9402                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 has often led to changes in regulations                 environmental conditions or other                     analysis determined that the risk of an
                                                 to address newly recognized unsafe                      operational conditions for which the                  explosion event due to an FQIS latent-
                                                 conditions. Second, because Boeing                      airplane is approved. If single failure               plus-one failure condition is not evenly
                                                 mentioned only that rule, we infer that                 conditions that jeopardize safe                       shared by all flights of airplanes of the
                                                 Boeing may be suggesting that section                   operation of the airplane (catastrophic               affected design. Instead, the risk of an
                                                 25.1309(b) of the Federal Aviation                      or hazardous conditions) are identified               FQIS-related fuel tank ignition event is
                                                 Regulations (14 CFR 25.1309(b)) is the                  as part of this examination, the design               largely concentrated on the subset of
                                                 most relevant safety analysis standard                  is considered to be non-compliant with                flights that occur with a pre-existing
                                                 applicable to the FQIS. As discussed                    section 25.901(c) of the Federal Aviation             latent failure condition and that operate
                                                 above, even if later changes to section                 Regulations (14 CFR 25.901(c)).                       with flammable conditions in the center
                                                 25.981 of the Federal Aviation                             Finally, the SFAR 88 AD-decision                   fuel tank. Based on Boeing’s data, such
                                                 Regulations (14 CFR 25.981) are not                     policy (Policy Memo ANM–100–2003–                     flights are reasonably anticipated to
                                                 considered and only the original                        112–15) (http://rgl.faa.gov/Regulatory_               occur.
                                                 certification basis for the Model 757 is                and_Guidance_Library/rgPolicy.nsf/0/                     For those flights, the risk exceeds the
                                                 applied, there are safety standards more                DC94C3A46396950386256D5E006                           allowable threshold for individual flight
                                                 specific to powerplant installations                    AED11?OpenDocument&Highlight                          safety risk in the TARAM policy. In
                                                 including fuel tanks and FQIS than                      =anm-100-2003-112-15) classifies a                    addition, that risk on those flights is due
                                                 section 25.1309(b) of the Federal                       ‘‘latent-plus-one’’ condition in a high               to a single additional failure, which is
                                                 Aviation Regulations (14 CFR                            flammability fuel tank as an unsafe                   inconsistent with the fail-safe design
                                                 25.1309(b)).                                            condition requiring corrective action.                philosophy; that philosophy is
                                                    The original certification basis for                 That policy actually provides some                    fundamental to the excellent safety
                                                 Model 757 airplanes included section                    relief from the latent-plus-one criteria              record of transport airplanes. (See FAA
                                                 25.901(c) of the Federal Aviation                       contained in the airworthiness                        Advisory Circular (AC) 25.1309–1A,
                                                 Regulations (14 CFR 25.901(c)) (http://                 regulations.                                          ‘‘System Design and Analysis,’’ dated
                                                 rgl.faa.gov/Regulatory_and_Guidance_                       We have not changed this SNPRM
                                                                                                                                                               June 21, 1998 (http://www.faa.gov/
                                                 Library/rgFar.nsf/FARSBySectLookup/                     regarding this issue.
                                                                                                                                                               documentLibrary/media/Advisory_
                                                 25.901) at Amendment 25–40.                             Request To Withdraw NPRM (77 FR                       Circular/AC%2025.1309-1.pdf), for a
                                                 According to that subsection, ‘‘For each                12506, March 1, 2012): Not Supported                  discussion of the fail-safe design
                                                 powerplant and auxiliary power unit                     by Risk Analysis                                      philosophy.) We would normally
                                                 installation, it must be shown that no
                                                                                                            Airlines for America (A4A) proposed                classify either of those conditions as an
                                                 single failure or malfunction or probable
                                                                                                         that we re-evaluate the NPRM (77 FR                   unsafe condition. Based on this risk
                                                 combination of failures will jeopardize
                                                                                                         12506, March 1, 2012) because it is ‘‘not             analysis, we have determined that the
                                                 the safe operation of the airplane. . . .’’
                                                                                                         founded on a data-based risk analysis.’’              individual flight safety risk due to this
                                                 (The FQIS is considered to be part of the
                                                 powerplant installation in accordance                   A4A stated that the FAA determined                    issue on the worst anticipated flights
                                                 with the definition in section 25.901(a)                that an unsafe condition exists based                 does not meet the minimum level of
                                                 of the Federal Aviation Regulations (14                 only on non-compliance with one SFAR                  safety required by the FAA and
                                                 CFR 25.901(a)).) Section 25.901(c) of the               88 criterion. A4A noted that the design               expected by the public. We have not
                                                 Federal Aviation Regulations (14 CFR                    approval holder, Boeing, has performed                changed this SNPRM regarding this
                                                 25.901(c)) sets a more stringent                        a numerical probability analysis and has              issue.
                                                 applicable standard than that of section                calculated that the probability of a fuel             Request To Withdraw or Delay NPRM
                                                 25.1309(b) of the Federal Aviation                      tank explosion due to the FQIS issue is               (77 FR 12506, March 1, 2012): Need
                                                 Regulations (14 CFR 25.1309(b)) for                     approximately one event per billion                   Detailed Risk Assessment
                                                 catastrophic failure conditions that are                flight hours, with cargo airplanes being
                                                 due to latent failure conditions                        slightly better due to a lower average                  FedEx requested that we revise the
                                                 combined with a subsequent single                       tank flammability. A4A also stated that               NPRM (77 FR 12506, March 1, 2012) to
                                                 failure condition (referred to as ‘‘latent-             existing ignition-prevention ADs have                 provide a numerical risk assessment
                                                 plus-one’’ conditions).                                 reduced the overall risk of an ignition               justifying the proposed action. UPS
                                                    The more stringent intent of section                 event to a level that questions the need              made a similar comment. UPS stated
                                                 25.901(c) of the Federal Aviation                       for FQIS modification. We infer that the              that, if the FAA has gathered new data
                                                 Regulations (14 CFR 25.901(c)) (http://                 commenter is requesting that we                       since the issuance of the ‘‘Reduction of
                                                 rgl.faa.gov/Regulatory_and_Guidance_                    withdraw the NPRM.                                    Fuel Tank Flammability in Transport
                                                 Library/rgFar.nsf/FARSBySectLookup/                        We disagree to withdraw the NPRM                   Category Airplanes’’ rule (73 FR 42444,
                                                 25.901) is discussed in further detail in               (77 FR 12506, March 1, 2012). We                      July 21, 2008) (http://www.gpo.gov/
                                                 the notice of proposed rulemaking and                   performed a qualitative risk assessment               fdsys/pkg/FR-2008-07-21/pdf/E8-
                                                 the preamble that were published for                    in accordance with our published SFAR                 16084.pdf), referred to as the Fuel Tank
                                                 Amendment 25–102. The FAA’s long-                       88 unsafe condition determination                     Flammability Reduction (FTFR) rule,
                                                 standing practice in applying the ‘‘no                  policy based on Boeing’s submitted                    the FTFR working group should be
                                                 single failure or malfunction’’ clause of               SFAR 88 design review, and determined                 reconvened in order to collaborate and
                                                 section 25.901(c) of the Federal Aviation               that the FQIS design on the Model 757                 discuss the proposed safety risk, assess
                                                 Regulations (14 CFR 25.901(c)) has been                 series airplanes presents an unsafe                   the risk statistically, evaluate solutions
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                                                 to apply that standard to all reasonably                condition and that AD action was                      and options, and establish accurate cost
                                                 anticipated flights—not simply to an                    warranted under that policy. We also                  and economic impact for the options.
                                                 average flight or an ideal flight. As such,             performed a data-based numerical risk                 FedEx provided an analysis showing
                                                 we examine all conditions: Flights with                 analysis using data provided by the                   that the total risk of a tank explosion
                                                 reasonably anticipated pre-existing                     manufacturer, and assessed the risk                   due to this issue on the fleet of Model
                                                 failure conditions, flights with                        under the transport airplane unsafe                   757 cargo airplanes is relatively low. We
                                                 inoperative equipment allowed for                       condition criteria in the TARAM policy                infer that the commenters are requesting
                                                 dispatch, and flights in adverse                        currently used by the FAA. Our risk                   that we withdraw or delay the NPRM.


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                                                                       Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                            9403

                                                    We disagree with the request to                      the unsafe condition identified in the                therefore would not have a significant
                                                 withdraw the NPRM (77 FR 12506,                         NPRM is inconsistent with the working                 effect on either the number of flights
                                                 March 1, 2012), pending review of the                   group analysis and lacks new data or                  that occur with a latent failure condition
                                                 FAA’s numerical risk assessment by the                  evidence indicating that ‘‘excessive                  or the FQIS-related fuel tank explosion
                                                 ‘‘FTFR working group.’’ The Aviation                    flammability or other known unsafe                    risk level on those flights estimated in
                                                 Rulemaking Advisory Committee                           condition exists, or is likely to                     the FAA’s risk assessment. We have not
                                                 (ARAC) Fuel Tank Harmonization                          develop.’’ Finally, UPS made the                      changed this SNPRM regarding this
                                                 Working Group (FTHWG) was tasked to                     following observation about the NPRM:                 issue.
                                                 recommend new rulemaking to                                The NPRM fails to consider the beneficial          Request To Withdraw NPRM (77 FR
                                                 eliminate or significantly reduce the risk              effects of the timing and effects of the              12506, March 1, 2012): No Unsafe
                                                 of exposure to flammable fuel-air                       maintenance action in response to a single
                                                                                                                                                               Condition
                                                 mixtures in fuel tanks. The ARAC                        in-tank or out-of-tank failure mode, or the
                                                 FTHWG issued its final report in 1998.                  beneficial effects of previous airworthiness             Airbus acknowledged that the latent-
                                                 The subsequent ARAC Fuel Tank                           directives and other SFAR 88 related actions          plus-one scenarios that prompted the
                                                 Inerting Harmonization Working Group                    taken to mitigate the proposed risk and               unsafe condition determination are a
                                                                                                         reduce the probability.                               technical possibility, but stated that the
                                                 (FTIHWG) was tasked to provide data
                                                 needed for the FAA to evaluate the                         We infer that the commenter is                     failure combinations that can create an
                                                 feasibility of implementing regulations                 requesting that we withdraw the NPRM                  ignition source are extremely
                                                 that would require eliminating or                       (77 FR 12506, March 1, 2012). We                      improbable. Airbus also stated that AD-
                                                 significantly reducing the development                  disagree with the request to withdraw                 required airworthiness limitations
                                                 of flammable vapors in fuel tanks on                    the NPRM. The FAA has performed a                     related to FQIS have significantly
                                                 transport-category airplanes. This effort               risk assessment and has determined that               reduced the likelihood of an FQIS-
                                                 was an extension of the previous work                   an unsafe condition does exist, both                  related fuel tank ignition event. We infer
                                                 performed by the FTHWG. The ARAC                        from a design architectural standpoint                that Airbus is requesting that we
                                                 FTIHWG issued its final report in 2002.                 and a numerical risk standpoint. The                  withdraw the NPRM (77 FR 12506,
                                                 The FAA’s work in developing the                        basis for that determination is discussed             March 1, 2012) based on Airbus’s
                                                 SFAR 88 corrective action decision                      in detail in the responses to ‘‘Request to            contention that no unsafe condition
                                                 policy and in determining specific                      Withdraw NPRM (77 FR 12506, March                     exists.
                                                 unsafe conditions was outside the scope                 1, 2012): Unjustified by Risk’’ and                      We agree to clarify the likelihood that
                                                 and charter of these working groups that                ‘‘Request to Withdraw NPRM (77 FR                     the unsafe condition could occur. The
                                                 contributed to the FTFR rule (73 FR                     12506, March 1, 2012): Not Supported                  FAA’s unsafe condition determination
                                                 42444, July 21, 2008). We determined                    by Risk Analysis’’ in this SNPRM.                     was not based on an assessment of
                                                 that an unsafe condition exists in                         The requirements of section                        average risk. We agree that the average
                                                 accordance with the SFAR 88 corrective                  25.981(a)(3) of the Federal Aviation                  risk of a fuel tank explosion on the
                                                 action decision policy and TARAM                        Regulations (14 CFR 25.981(a)(3))                     Model 757 is likely to be lower than the
                                                 policy. We have provided a summary of                   cannot be met with an approved                        numerical guidance for ‘‘extremely
                                                 our risk assessment as discussed in the                 maintenance program only. While an                    improbable’’ of 1.0x10E–9 per flight
                                                 responses to ‘‘Request to Withdraw                      appropriate maintenance program is                    hour. We also agree that the average risk
                                                 NPRM (77 FR 12506, March 1, 2012):                      required, section 25.981(a)(3) of the                 was likely reduced by AD-required
                                                 Unjustified by Risk’’ and ‘‘Request to                  Federal Aviation Regulations (14 CFR                  airworthiness limitations that specify
                                                 Withdraw NPRM (77 FR 12506, March                       25.981(a)(3)) has the effect of setting               extra checks after in-tank work, and
                                                 1, 2012): Not Supported by Risk                         minimum requirements for the design                   adequate separation of newly installed
                                                 Analysis’’ in this SNPRM. As explained                  architecture and the reliability of system            out-of-tank wiring from FQIS wiring.
                                                 previously (see ‘‘Request to Withdraw                   elements. The Model 757 FQIS as                          As discussed in ‘‘Request to
                                                 NPRM (77 FR 12506, March 1, 2012):                      originally designed does not meet all of              Withdraw NPRM (77 FR 12506, March
                                                 Unjustified by Risk’’ in this SNPRM),                   those requirements. Previous AD                       1, 2012): Unjustified by Risk’’ in this
                                                 the FAA determined the unsafe                           actions, other than the required                      SNPRM, however, the FAA’s unsafe
                                                 condition based on the unacceptable                     maintenance program revisions                         condition determination was driven by
                                                 risk on anticipated flights with a latent               included in AD 2012–12–15,                            the identification of an unacceptable
                                                 FQIS failure and flammable fuel tank                    Amendment 39–17095 (77 FR 42964,                      level of individual risk that exists on
                                                 conditions, not the total fleet risk. We                July 23, 2012) (which superseded AD                   flights that are anticipated to occur with
                                                 have not changed this SNPRM regarding                   2008–10–11, Amendment 39–15517 (73                    a pre-existing latent in-tank failure
                                                 this issue.                                             FR 25974, May 8, 2008)), have no effect               condition and with a flammable center
                                                                                                         on the level of individual flight risk that           fuel tank. In the remaining life of the
                                                 Request To Withdraw NPRM (77 FR                         has been determined to be an unsafe                   affected airplanes, a significant number
                                                 12506, March 1, 2012): No Unsafe                        condition. Some of the airworthiness                  of such flights are reasonably
                                                 Condition                                               limitations (AWLs) introduced by AD                   anticipated to occur—even with the
                                                   UPS stated that an SFAR 88 working                    2012–12–15 will reduce the rate of                    improvements expected under the
                                                 group analyzed potential fuel tank                      introduction of additional risks due to               AWLs required by AD 2012–12–15,
                                                 ignition sources and that maintenance                   future maintenance errors or                          Amendment 39–17095 (77 FR 42964,
                                                 programs were revised using MSG3                        modifications compromising required                   July 23, 2012). For those flights, a fuel
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                                                 methodology to meet the revised criteria                design features, but are not expected to              tank explosion can be caused by an
                                                 in ‘‘14 CFR 25.981(3).’’ (We assume UPS                 prevent all errors. Those AWLs do not                 additional single wiring failure. In
                                                 intended to refer to section 25.981(a)(3)               address problems that may already exist               addition, the manufacturer’s estimated
                                                 of the Federal Aviation Regulations (14                 or develop on in-service airplanes                    probability of such a failure (the
                                                 CFR 25.981(a)(3))) (http://www.faa.gov/                 separate from maintenance activity, and               additional single wiring failure)
                                                 regulations_policies/advisory_circulars/                they do not address the basic non-                    significantly exceeds the FAA’s unsafe
                                                 index.cfm/go/document.information/                      compliant aspects of the original FQIS                condition numerical threshold for
                                                 documentID/73716).) UPS stated that                     design architecture. Those AWLs                       individual flight risk. The probability of


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                                                 9404                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 a fuel tank explosion on those flights is               mitigation means on a given airplane in               because inclusion could not be justified
                                                 not reduced by the existence of the                     accordance with the FTFR rule would                   in a cost-benefit analysis. The FTFR rule
                                                 above-mentioned AWLs. The AWL that                      be sufficient to address the FQIS latent-             was intended to enhance the
                                                 requires extra checks after in-tank work                plus-one unsafe condition. The FTFR                   airworthiness standards in a manner
                                                 has been done has the potential to                      rule was not intended to prevent the                  that would increase the level of safety
                                                 reduce the number of flights with a pre-                FAA from addressing that unsafe                       for affected airplanes over that ensured
                                                 existing in-tank failure condition. The                 condition on airplanes that would not                 by the existing regulations. That
                                                 AWL that requires newly installed                       be affected by the FTFR rule. This was                enhancement was expected to result
                                                 wiring to meet separation standards                     clearly stated in the preamble to the                 from an increased level of protection
                                                 should prevent a significant increase in                FTFR rule. We have not changed this                   from ignition sources that had not been
                                                 the risk on those flights that would have               SNPRM regarding this issue.                           identified by manufacturers in their
                                                 resulted from the installation of                                                                             safety analyses. That enhancement of
                                                                                                         Request To Withdraw NPRM (77 FR
                                                 additional, inadequately separated                                                                            the airworthiness standards was
                                                                                                         12506, March 1, 2012): Underestimated
                                                 wiring.                                                                                                       required to be justified by a cost-benefit
                                                    We have not changed this SNPRM                       Economic Impact
                                                                                                                                                               analysis. Cargo airplanes were excluded
                                                 regarding this issue.                                      Several commenters requested that we               because the FTFR rule safety
                                                                                                         withdraw the NPRM (77 FR 12506,                       enhancement could not be justified for
                                                 Request To Withdraw NPRM (77 FR                         March 1, 2012) because the FAA’s cost
                                                 12506, March 1, 2012) Based on Similar                                                                        those airplanes from a cost-benefit
                                                                                                         estimate was too low. A4A estimated                   standpoint.
                                                 Rulemaking for Cargo Airplanes                          that the costs associated with the NPRM                  This SNPRM would not require a
                                                    ASTAR Air Cargo (ASTAR) requested                    would be up to 3 times the $100,000 to                safety enhancement over the level of
                                                 that we withdraw the NPRM (77 FR                        $200,000 estimated by the FAA, and                    safety required by previous standards.
                                                 12506, March 1, 2012). In support of its                would be comparable with the cost of                  Instead, this SNPRM addresses an
                                                 request, ASTAR cited the TWA Flight                     Boeing’s NGS installation. Goodrich                   unsafe condition that was identified
                                                 800 accident investigation and its                      pointed out that any redesigned FQIS                  from the manufacturer’s SFAR 88 safety
                                                 finding that the most probable cause of                 would likely be subject to the current                analysis using the FAA’s published
                                                 the accident was a fuel tank explosion                  requirements of section 25.981 of the                 corrective action decision criteria for
                                                 due to a latent-plus-one failure of the                 Federal Aviation Regulations (14 CFR                  SFAR 88 identified design issues (see
                                                 FQIS. ASTAR stated that the FAA had                     25.981), resulting in higher costs than               section 25.981(a)(3) of the Federal
                                                 proposed the FTFR rule (73 FR 42444,                    estimated by the FAA. A4A speculated                  Aviation Regulations (14 CFR
                                                 July 21, 2008) to mitigate the risk of fuel             that these higher costs were the reason               25.981(a)(3) (http://www.faa.gov/
                                                 tank explosions, and that cargo                         the NGS was acknowledged as a method                  regulations_policies/advisory_circulars/
                                                 airplanes had been exempted from that                   of compliance in the NPRM. A4A and                    index.cfm/go/document.information/
                                                 requirement based on a cost-benefit                     UPS stated that the FAA appears to be                 documentID/73716). We deferred taking
                                                 analysis. ASTAR argued that, because                    using the NPRM as a method to require                 action on this unsafe condition until
                                                 the basis for exclusion of all cargo                    the installation of Boeing’s NGS (or                  after the FTFR rulemaking activity
                                                 aircraft from the FTFR rule has not                     equivalent actions) on airplanes that                 because the installation of an FRM
                                                 changed, all cargo aircraft should be                   were not included in the applicability of             would sufficiently address the FQIS
                                                 exempt from any corrective action for                   the FTFR rule (73 FR 42444, July 21,                  latent-plus-one unsafe condition. Now
                                                 the FQIS latent-plus-one issues, and the                2008) based on a cost-benefit analysis.               that the FTFR rulemaking process is
                                                 NPRM (77 FR 12506, March 1, 2012)                          Although we disagree to withdraw the               complete, we are resuming our activity
                                                 should be withdrawn.                                    NPRM, we agree with some of the                       to address these unsafe conditions via
                                                    We disagree with the request. We                     commenters’ assertions. We agree that                 AD actions. The Boeing NGS has been
                                                 have determined that an unsafe                          our original cost estimate was low. We                acknowledged as a method of
                                                 condition requiring corrective action                   agree to adjust the cost estimate, based              compliance in this SNPRM because the
                                                 exists in the Model 757 FQIS. The FTFR                  on the information provided by the                    Boeing NGS is an available design that
                                                 rule (73 FR 42444, July 21, 2008) was                   commenters, as discussed below under                  the FAA knows would address the
                                                 proposed not because of FQIS issues                     ‘‘Request to Revise Cost Estimate Based               unsafe condition. No additional change
                                                 specifically, but because of the history                on New Data.’’ Our original estimate                  was made to this SNPRM as a result of
                                                 of fuel tank explosions in the transport                was based on information provided                     this comment.
                                                 airplane fleet due to various causes, and               previously by manufacturers of original
                                                 an acknowledgement that industry and                    equipment FQIS, retrofit FQIS, and both               Request To Withdraw NPRM (77 FR
                                                 the FAA may not be able to anticipate                   original equipment and aftermarket                    12506, March 1, 2012) Due to Its
                                                 and prevent all of the fuel tank ignition               transient suppression and isolation                   Hidden Effects
                                                 sources that may arise due to design and                devices. Our current estimate has been                  A4A requested that we withdraw the
                                                 maintenance issues in the life of a fleet               increased to reflect the written                      NPRM (77 FR 12506, March 1, 2012)
                                                 of airplanes.                                           comments from and further discussions                 because of certain hidden effects that
                                                    The intent of the FTFR rule (73 FR                   with Boeing and Goodrich. There is no                 may not have been anticipated by the
                                                 42444, July 21, 2008) was to reduce the                 change to our determination that an                   FAA. A4A pointed out that some
                                                 overall exposure to flammable fuel tank                 unsafe condition exists. We are                       operators are already anticipating
                                                 conditions in the fleet by approximately                therefore proceeding with this AD                     difficulty in meeting the deadlines for
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                                                 one order of magnitude with the                         action based on the identified corrective             compliance with the FTFR rule (73 FR
                                                 expectation that this would have a                      actions that will address the unsafe                  42444, July 21, 2008). Based on A4A’s
                                                 significant impact on the rate of fuel                  condition.                                            assumption that airlines would comply
                                                 tank explosions in the future due to                       We disagree with the characterization              with the NPRM by incorporating
                                                 unanticipated causes. In promulgating                   that we are using the AD process to                   Boeing’s current NGS design, A4A
                                                 this improvement in the safety                          require an FRM to be installed on                     expressed concern that using Boeing’s
                                                 standards, the FAA acknowledged that                    airplanes that were excluded from the                 NGS for these additional airplanes
                                                 installation of FRM or ignition                         FTFR rule (73 FR 42444, July 21, 2008)                would potentially exceed the rate at


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                                                                       Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                            9405

                                                 which industry can modify the fleet                     a significant rule that would require a               address the FQIS issue with AD actions.
                                                 affected by the planned ADs and the                     cost-benefit analysis.                                The purpose of that statement was to
                                                 FTFR rule. A4A also noted that the                         We disagree with the request. First, in            note that there would be some cost
                                                 compliance time for the NPRM would                      assessing whether an AD is a significant              savings to industry resulting from the
                                                 overlap the compliance period for the                   rule in accordance with FAA policy, we                elimination of other actions required to
                                                 FTFR rule.                                              do not combine the cost of multiple                   address an unsafe condition for the
                                                    While we disagree with the request to                planned ADs for different airplanes,                  airplanes affected by the proposed rules,
                                                 withdraw the NPRM, we agree with                        even when the design issues and unsafe                and to point out that the FAA did not
                                                 some of the assertions made by the                      conditions addressed are similar.                     take credit for those potential cost
                                                 commenter. We agree with the concern                    Second, the changes discussed                         reductions in assessing the cost of the
                                                 that this AD action has the potential to                previously in this SNPRM will                         FTFR rule (73 FR 42444, July 21, 2008)
                                                 further burden the operators and                        significantly reduce the cost impact. We              because the costs were not well
                                                 modifiers that are working to meet the                  have made no further changes to this                  understood at the time. That statement
                                                 FRM operating rule deadlines, because                   SNPRM regarding this issue.                           was not a commitment by the FAA to
                                                 some additional airplanes are likely to                 Request To Withdraw NPRM (77 FR                       reverse its intentions to address an
                                                 be modified by installing FRM such as                   12506, March 1, 2012): Inadequate                     identified unsafe condition on the
                                                 Boeing’s NGS. But since we issued the                   Notice to Public                                      airplanes that are not required to
                                                 NPRM (77 FR 12506, March 1, 2012),                                                                            incorporate FRM. We have not changed
                                                                                                            A4A recommended that we provide                    this SNPRM regarding this issue.
                                                 two factors have changed that reduce
                                                                                                         information on any other designs that
                                                 A4A’s concern. First, we have identified                                                                      Request for Cost-Benefit Analysis
                                                                                                         have been reviewed under SFAR 88,
                                                 a less costly option for cargo airplanes,               and provide industry with information                    Boeing, FedEx, Airbus, ASTAR Air
                                                 which most cargo operators are                          regarding their planned disposition.                  Cargo, and A4A requested that we
                                                 expected to prefer over installation of                 A4A asserted that, during the FTFR                    perform a cost-benefit analysis for the
                                                 FRM. This is expected to result in                      rulemaking activity, we did not provide               NPRM (77 FR 12506, March 1, 2012)
                                                 significantly fewer airplanes competing                 notice to the industry that we still                  and publish the results. Airbus stated
                                                 for FRM modification resources.                         intended to address the FQIS issues                   that its own cost estimates exceed those
                                                 Second, this AD action has been                         identified via SFAR 88. We infer that                 used by the FAA for the FTFR rule (73
                                                 delayed due to numerous factors,                        A4A is requesting that we withdraw the                FR 42444, July 21, 2008) cost-benefit
                                                 including the number of comments, the                   NPRM (77 FR 12506, March 1, 2012)                     analysis that ended up excluding cargo
                                                 development of a different corrective                   based on inadequate notice to the public              airplanes. A4A and ASTAR Air Cargo
                                                 action option, and the resultant need to                and the chance to comment on the                      requested that the NPRM be withdrawn
                                                 extend the comment period to allow the                  proposal. The commenter stated that the               until a cost-benefit analysis is
                                                 public the chance to comment on these                   preamble of the FTFR rule (73 FR                      performed. The commenters suggested
                                                 proposed changes.                                       42444, July 21, 2008) was unclear                     that a cost-benefit analysis would show
                                                    Also, as discussed below under                       regarding whether AD actions would be                 that the NPRM cannot be justified
                                                 ‘‘Request to Extend Compliance Time                     taken to address the FQIS issues on                   because the costs of the proposed
                                                 Pending Issuance of Service                             airplanes that were not required to                   actions would exceed the monetary
                                                 Information,’’ we have extended the                     incorporate FRM.                                      value of the AD’s safety benefits. The
                                                 proposed compliance time by 12                             We disagree with the request to                    commenters cited the cost-benefit
                                                 months. These delays and changes will                   withdraw the NPRM (77 FR 12506,                       analysis that was performed to justify
                                                 result in the AD compliance deadline                    March 1, 2012). We determined that an                 the FTFR rule, and pointed out that a
                                                 being at least 3 years beyond the final                 unsafe condition exists. FTFR                         requirement for FRM could not be
                                                 compliance deadline of the FTFR rule                    rulemaking was done because the FAA                   justified for the airplanes that would be
                                                 (73 FR 42444, July 21, 2008). Similar                   recognized the benefit for the specific               affected by the proposed AD.
                                                 planned ADs for other models have                       design changes involving incorporation                   We infer that, pending a full cost-
                                                 been similarly delayed. We have                         of FRM required by the FTFR rule (73                  benefit analysis, these commenters are
                                                 determined that the industry                            FR 42444, July 21, 2008) to enhance fuel              requesting that we either withdraw the
                                                 modification capacity will be sufficient                tank safety. Because the FTFR final rule              NPRM or delay this action further until
                                                 to support the modification of the                      requires action on only a subset of the               a cost-benefit analysis demonstrates that
                                                 expected additional airplanes receiving                 airplanes that have the FQIS unsafe                   an AD is justified in this case. We
                                                 FRM within the new proposed                             condition, we are taking action to                    disagree. The FAA’s process and legal
                                                 compliance time. We have not changed                    address the remaining airplanes that                  obligations for introducing new
                                                 this SNPRM further regarding this issue.                will continue to have the unsafe                      airworthiness standards are different
                                                 Request To Withdraw NPRM (77 FR                         condition if no further corrective action             from those for initiating an AD to
                                                 12506, March 1, 2012): Potential                        is taken.                                             address an unsafe condition in an
                                                                                                            The commenter has taken the                        existing product. In addition, the
                                                 Significant Rule
                                                                                                         statement from the FTFR preamble out                  commenters’ assertions were based on
                                                   A4A stated that the combined costs of                 of context. In fact, the paragraph from               the assumption that the only design
                                                 the NPRM (77 FR 12506, March 1, 2012)                   which the commenter quoted                            solution that would be made available
                                                 and other anticipated ADs for U.S.                      specifically states that the FAA                      to address the solution would be an
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                                                 airplane models with an FQIS latent-                    expected to take AD action to address                 FRM, or another solution of similarly
                                                 plus-one issue would exceed $177                        FQIS issues identified through SFAR 88                high cost.
                                                 million and would require a cost-benefit                analyses. The paragraph simply states                    When we propose a new
                                                 analysis. We infer that the commenter is                that the proposed FRM has the potential               airworthiness standard, as in the case of
                                                 requesting we withdraw the NPRM (77                     to reduce the industry cost associated                the FTFR rule (73 FR 42444, July 21,
                                                 FR 12506, March 1, 2012) on the basis                   with those expected ADs because the                   2008), we are required to perform a cost-
                                                 that the planned ADs for various                        installation of an FRM likely would                   versus-benefit comparison to justify the
                                                 models, if combined, would qualify as                   eliminate the need for action to further              application of the new standard. The


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                                                 9406                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 decision in that rulemaking action—to                   to be addressed for airplanes that would              operation of the air conditioning system
                                                 not require FRM installation on cargo                   have been subject to the FTFR rule in                 on the ground significantly contributes
                                                 airplanes—was based in significant part                 the U.S., and suggested that EASA                     to the heating of the center fuel tank.
                                                 on cost estimates that industry provided                might have to issue an AD (instead of                 Boeing’s analysis estimated a fleet
                                                 to show that AD-required FQIS design                    adopting the FAA AD), with similar                    average flammability for the center fuel
                                                 changes would be far less costly than                   technical content, but extending the                  tanks of the cargo airplane fleet of 50
                                                 installing FRM on cargo airplanes. We                   applicability to the entire Model 757                 percent of the level for the passenger
                                                 specifically considered the option to not               fleet in Europe.                                      fleet. Boeing also noted that cargo
                                                 require retrofit of cargo airplanes with                   We agree to revise the applicability.              airplanes generally accumulate flight
                                                 FRM because of the expectation that                     EASA is correct that the unsafe                       hours at a lower rate than passenger
                                                 alternative design solutions to address                 condition potentially affects all Model               airplanes.
                                                 the specific, known unsafe condition of                 757 airplanes, whereas the applicability                 We disagree with the request to
                                                 FQIS latent-plus-one vulnerability                      statement in the NPRM (77 FR 12506,                   withdraw the NPRM (77 FR 12506,
                                                 would still be required through AD                      March 1, 2012) could be interpreted as                March 1, 2012).
                                                 actions. For this AD action, however,                   not covering airplanes in passenger                      We acknowledge that the increased
                                                 industry submitted written comments                     service that are not operated under parts             night operation and reduced use of the
                                                 and made verbal statements that the cost                121, 125, or 129 of the Federal Aviation              air conditioning system on the ground
                                                 of an FQIS design solution would be                     Regulations (14 CFR part 121, 125, or                 reduce the average flammability
                                                 comparable to, and possibly greater                     129). The EASA comment makes it                       exposure for the fleet of cargo airplanes
                                                 than, the cost of its FRM modification.                 apparent that the proposed applicability              relative to the fleet of passenger
                                                    In general, a full cost-benefit analysis             statement may be unclear to some                      airplanes. That reduction in fleet
                                                 is rarely required for an AD. As a matter               operators and regulatory authorities.                 average flammability, however, is not
                                                 of regulation, in order to be airworthy,                While the applicability statement in the              sufficient to allow the center fuel tanks
                                                 an aircraft must conform to its type                    NPRM is technically correct (e.g., an                 on those airplanes to be classified as
                                                 design and be in a condition for safe                   EASA operator is not operating under                  low flammability fuel tanks. The FAA’s
                                                 operation. The type design is approved                  those FAA operating rules and therefore               determination that an unsafe condition
                                                 only after the FAA makes a                              would have been subject to the AD), we                exists for the cargo airplanes as well as
                                                 determination that the design complies                  now agree that there is a potential for               passenger airplanes was driven by the
                                                 with all applicable airworthiness                       confusion that can be eliminated by                   FAA’s individual risk safety decision
                                                 requirements. In adopting and                           more directly stating the requirement                 criteria rather than an average risk or
                                                 maintaining those requirements, the                     and applicability in a manner similar to              fleet risk criterion. There is no
                                                 FAA has already made the                                that proposed by EASA in their                        difference in the individual flight risk
                                                 determination that those requirements                   comment. We have changed the                          on the worst anticipated flights between
                                                 establish a level of safety that is cost                applicability in this SNPRM to all                    passenger airplanes and cargo airplanes
                                                 beneficial. A finding of an unsafe                      Model 757 airplanes except for                        due to this issue. The worst anticipated
                                                 condition that warrants AD action                       airplanes equipped with an FRM                        flights in either case involve a pre-
                                                 means that this cost-beneficial level of                approved by the FAA as compliant with                 existing latent in-tank failure and
                                                 safety is no longer being achieved, and                 the FTFR requirements of section                      operation with flammable conditions in
                                                 the required AD actions are necessary to                26.33(c)(1) of the Federal Aviation                   the center fuel tank. Flights with that
                                                 restore that level of safety. Because this              Regulations (14 CFR 26.33(c)(1)), as                  combination of conditions are
                                                 level of safety has already been                        discussed below. As with any required                 anticipated to occur in both the
                                                 determined to be cost beneficial and                    equipment, the FRM must be                            passenger fleets and cargo fleets
                                                 does not add an additional regulatory                   operational with the exception of any                 (although at a somewhat lower relative
                                                 requirement, a full cost-benefit analysis               relief granted under master minimum                   rate on cargo airplanes, for the reasons
                                                 for each AD would be redundant and                      equipment list (MMEL) provisions.                     cited by the commenters).
                                                 unnecessary.                                               With the clarification in paragraph (c),              For those flights, a fuel tank explosion
                                                    We have not changed this SNPRM                       ‘‘Applicability,’’ of this SNPRM, we                  could occur due to a single failure in the
                                                 regarding this issue.                                   have determined that paragraph (h),                   airplane wiring or the FQIS processor
                                                                                                         ‘‘Optional Installation of Flammability               that conducts a high level of electrical
                                                 Request To Revise Applicability                                                                               energy onto circuits that enter the fuel
                                                                                                         Reduction Means,’’ of the NPRM would
                                                 Statement To Clarify the Intent of the                                                                        tank. As discussed previously in the
                                                                                                         be superfluous and is no longer
                                                 Rule for Non-U.S.-Registered Airplanes                                                                        response to ‘‘Request to Withdraw
                                                                                                         necessary. Paragraph (c) of this
                                                    The European Aviation Safety Agency                  supplemental NPRM, as revised, would                  NPRM (77 FR 12506, March 1, 2012):
                                                 (EASA), the Technical Agent for the                     not apply to airplanes equipped with                  Unjustified by Risk,’’ this is not
                                                 Member States of the European                           FRM.                                                  consistent with the FAA’s fail-safe
                                                 Community, requested that we revise                                                                           design philosophy for transport
                                                 the proposed applicability. Specifically,               Requests To Withdraw NPRM (77 FR                      airplanes. In addition, the numerical
                                                 EASA requested that we add Model 757                    12506, March 1, 2012) Based on                        probability of the single failure as
                                                 airplanes that did not have FRM                         Applicability                                         estimated by the manufacturer and the
                                                 installed in production. EASA further                      Boeing and ASTAR Air Cargo                         FAA significantly exceeds the unsafe
                                                 requested that we exclude airplanes                     requested that we withraw the NPRM                    condition threshold for individual flight
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                                                 equipped with FRM that meet the FAA’s                   (77 FR 12506, March 1, 2012) because                  risk in the FAA’s TARAM) Policy
                                                 FTFR rule (73 FR 42444, July 21, 2008).                 cargo airplanes on average have a lower               Statement PS–ANM–25–05 (http://
                                                 EASA stated that it has not issued an                   flammability exposure due to a larger                 rgl.faa.gov/Regulatory_and_Guidance_
                                                 operating regulation corresponding to                   portion of night operations (with                     Library/rgPolicy.nsf/0/4E5AE87071646
                                                 the FAA’s requirements for retrofitting                 resultant cooler outside air                          74A862579510061F96B?Open
                                                 FRM in the FTFR rule. EASA noted that,                  temperatures) and a lower rate of                     Document&Highlight=ps-anm-25–05).
                                                 at least for European operators, the                    utilization of the cabin air conditioning             We have therefore determined that an
                                                 unsafe condition would not be required                  system on the ground. Boeing stated that              unsafe condition does exist on cargo


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                                                                       Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                             9407

                                                 airplanes even in consideration of the                  exemption, and they indicated their                   for a portion of their operating time, and
                                                 lower fleet exposure factors cited by the               willingness to make such a petition.                  the criteria include ignition prevention
                                                 commenters.                                               We have added new paragraph (h) in                  thresholds commensurate with that
                                                    While we have determined that this                   this SNPRM to allow repetitive FQIS                   level of flammability. The regulatory
                                                 unsafe condition requires corrective                    built-in test equipment (BITE) checks                 performance standard for FRMs is
                                                 action, we have identified additional                   and modification of the airplane by                   equivalent to the flammability of a
                                                 corrective action options that we expect                separating FQIS wiring from other                     conventional aluminum wing tank,
                                                 will be significantly less costly to                    aircraft wiring that is not intrinsically             which is the benchmark for the
                                                 incorporate than the originally proposed                safe (in a manner acceptable to the FAA)              definition of a low-flammability tank.
                                                 requirement. We have determined that                    as an additional option for airplanes                 We have therefore determined that it is
                                                 this additional corrective action option                used exclusively for cargo operations.                appropriate to treat ignition sources in
                                                 is not suitable for passenger airplanes                 We have redesignated subsequent                       center fuel tanks with compliant FRMs
                                                 because it does not provide a sufficient                paragraphs of this SNPRM accordingly.                 the same way they would be treated for
                                                 level of risk reduction for passenger                   Request To Change Applicability To                    a tank that has inherent low
                                                 operations. The FAA normally does not                   Address Unsafe Condition on Airplanes                 flammability. Because the FQIS latent-
                                                 differentiate between the safety                        With FRM                                              plus-one vulnerability for Model 757
                                                 requirements or corrective action                                                                             airplanes was classified as a theoretical
                                                                                                            National Air Traffic Controllers                   vulnerability and not as a condition
                                                 requirements for cargo airplanes and
                                                                                                         Association (NATCA) requested that we                 known to have occurred, the SFAR 88
                                                 passenger airplanes. However, after
                                                                                                         revise the NPRM (77 FR 12506, March                   corrective action policy does not require
                                                 reviewing all of the comments on the
                                                                                                         1, 2012) to include airplanes on which                corrective action for that condition in
                                                 estimated high cost of the corrective
                                                                                                         FRMs were incorporated either                         low-flammability fuel tanks. The
                                                 action and the uncertainty in those
                                                                                                         voluntarily or to comply with the FTFR                installation of an FRM causes the center
                                                 estimates, we examined other options
                                                                                                         rule (73 FR 42444, July 21, 2008).                    fuel tank to meet the criteria for
                                                 for less costly risk reduction on cargo                 NATCA noted that the introduction of
                                                 airplanes. We identified an option that                                                                       classification as a low-flammablity fuel
                                                                                                         FRM on such airplanes only reduces the                tank, and therefore FRM installation
                                                 provides significant risk reduction at a                fraction of time the airplane is operated
                                                 per-airplane cost that is estimated to be                                                                     was considered to be acceptable
                                                                                                         with flammable conditions in its fuel                 mitigating action. We have not changed
                                                 less than one-quarter of the cost of the                tanks, but does not eliminate flammable
                                                 original proposal (77 FR 12506, March                                                                         this SNPRM regarding this issue.
                                                                                                         operation. NATCA further noted that
                                                 1, 2012). The amount of risk reduction                  FAA operating rules allow limited                     Request To Remove Requirement for
                                                 from this option is not at this time                    operation of the airplane with the FRM                Goodrich FQIS
                                                 considered to be adequate to address the                inoperative. NATCA added that the                        Goodrich stated that its FQIS fuel
                                                 unsafe condition for passenger                          likelihood of a fuel tank explosion                   height and dielectric sensor interface
                                                 airplanes.                                              during operation with flammable tanks                 circuitry presently meets the energy,
                                                    In this case, the FAA is proposing to                is similar regardless of whether an FRM               voltage, and current limits specified in
                                                 accept a higher level of individual flight              is installed.                                         FAA AC 25.981–1C, ‘‘Fuel Tank Ignition
                                                 risk exposure for cargo flights that are                   We disagree with the request. We                   Source Prevention Guidelines,’’ dated
                                                 not fail-safe due to the absence of                     have developed and published policy                   September 19, 2008 (http://
                                                 passengers and the resulting significant                for determination of unsafe conditions                www.faa.gov/regulations_policies/
                                                 reduction in occupant exposure on a                     and the need for corrective actions                   advisory_circulars/index.cfm/go/
                                                 cargo airplane versus a passenger                       during the evaluation of SFAR 88 fuel                 document.information/documentID/
                                                 airplane, and due to relatively low                     tank safety review findings. The                      73716). Goodrich stated that the system
                                                 estimated individual flight risk that                   decision to allow FRM as an acceptable                design would require multiple serial
                                                 would exist on a cargo airplane after the               mitigating action for the identified                  failures to enable a fault to propagate to
                                                 corrective actions are taken. The FAA                   unsafe condition is consistent with that              the tank, resulting in the combination of
                                                 has allowed a higher risk level to exist                policy. We acknowledge NATCA’s point                  those failures being extremely
                                                 on cargo airplanes due to other issues,                 that, if no actions are taken on an                   improbable on average. Goodrich added
                                                 and applies a slightly less stringent                   airplane to correct the FQIS latent-plus-             that the system built-in test detects open
                                                 numerical fleet risk threshold standard                 one issue other than installation of an               circuits and short circuits in the sensors
                                                 for unsafe conditions in the published                  FRM, flights on that airplane where                   and aircraft wiring, including shorts to
                                                 TARAM policy. Because this is an                        FRM is inoperative or ineffective would               structure. Goodrich stated that there
                                                 unusual determination, we have                          have the same risk of a fuel tank                     have been no failures in service in
                                                 reopened the comment period to give                     explosion due to the FQIS latent-plus-                which the Goodrich FQIS exposed the
                                                 affected operators, pilots, and the public              one issue as flights on an airplane with              fuel tank to an unsafe condition.
                                                 the opportunity to comment on this                      no FRM installed. However, the                        Goodrich asked whether the actual
                                                 proposal.                                               published unsafe condition criteria                   system operation and service life have
                                                    We expect that the optional wire                     (section 25.981(a)(3) of the Federal                  been considered in the evaluation of the
                                                 separation design change to support                     Aviation Regulations (14 CFR                          probability of an unsafe condition and
                                                 compliance with the proposed AD for                     25.981(a)(3)) (http://www.faa.gov/                    the mitigation provided by the present
                                                 cargo airplanes will involve the                        regulations_policies/advisory_circulars/              Goodrich FQIS.
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                                                 manufacturer or any other modifier                      index.cfm/go/document.information/                       We infer that the commenter is
                                                 petitioning for a partial exemption from                documentID/73716) differentiate                       requesting that we revise the NPRM (77
                                                 the ‘‘latent-plus-one’’ requirements of                 between low- and high-flammability                    FR 12506, March 1, 2012) to eliminate
                                                 sections 25.901(c) and 25.981(a)(3) of                  fuel tanks, with a higher level of                    any requirement for corrective action for
                                                 the Federal Aviation Regulations (14                    conservatism applied to high-                         airplanes equipped with a Goodrich
                                                 CFR 25.901(c) and 14 CFR 25.981(a)(3)).                 flammability tanks.                                   FQIS. We partially agree. The Goodrich
                                                 We have informed the manufacturer that                     The criteria recognize that low-                   system is recognized as having
                                                 we are open to granting such an                         flammability tanks are still flammable                significant improvements relative to the


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                                                 9408                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 original 757 system developed by                        fuel tank (for example, because of                    of the later-developed SFAR 88 unsafe
                                                 another manufacturer. We recognize                      common wiring between the tanks),                     condition criteria. We have not changed
                                                 that the Goodrich FQIS has the ability                  then that modification would be                       this SNPRM regarding this issue.
                                                 to identify a significant portion of the                required. Paragraph (g) of this SNPRM
                                                                                                                                                               Request for Specific Corrective Action
                                                 potential latent in-tank failure                        already states this (‘‘modify the FQIS
                                                 conditions that can occur inside the fuel               wiring or fuel tank systems to prevent                   EASA noted that the NPRM (77 FR
                                                 tanks. Those conditions, however, are                   development of an ignition source                     12506, March 1, 2012) did not cite
                                                 detected and corrected only when the                    inside the center fuel tank’’). A change              service information for a specific design
                                                 built-in test capability is activated                   to this SNPRM itself therefore is not                 solution other than acknowledging FRM
                                                 during maintenance. Currently,                          necessary.                                            as an acceptable method of compliance.
                                                 activating the built-in test features is                                                                      We infer that EASA is requesting that
                                                                                                         Request To Revise Proposed AD                         the NPRM propose to require a specific
                                                 required only when troubleshooting an
                                                                                                         Requirements To Apply to All Fuel                     corrective action for the unsafe
                                                 FQIS problem that has become apparent
                                                                                                         Tanks                                                 condition. EASA pointed out that,
                                                 to flight or maintenance crew. This still
                                                 potentially leaves significant latency                     NATCA noted that action similar to                 under its regulations and policies,
                                                 periods for those failures.                             the proposed requirements of the NPRM                 EASA issues ADs based on specific
                                                    We have agreed that the Goodrich                     (77 FR 12506, March 1, 2012) was                      solutions provided by the responsible
                                                 processor has sufficient circuit isolation              required for all fuel tanks on early                  manufacturer. EASA stated that, in the
                                                 such that the processor itself is not                   Model 747 and 737 airplanes via AD                    absence of a specific solution, EASA
                                                 expected to create hot short conditions                 98–20–40, Amendment 39–10808 (63                      will not be in a position to simply adopt
                                                 in tank circuits, and is not expected to                FR 52147, September 30, 1998); and AD                 the FAA AD, and may need to develop
                                                 pass energy from non-tank-side low-                     99–03–04, Amendment 39–11018 (64                      its own AD or find another solution.
                                                 voltage hot shorts onto tank-side                       FR 4959, February 2, 1999). The                          We disagree with the request to
                                                 circuits. There remains, however, a                     commenter also noted that the FAA’s                   require a specific corrective action in
                                                 significant potential for a single failure              published SFAR 88 unsafe condition                    this SNPRM. In this case, the
                                                 causing a hot short onto tank-side                      criteria (section 25.981(a)(3) of the                 manufacturer has not provided a
                                                 circuits, or a single failure causing a                 Federal Aviation Regulations (14 CFR                  corrective action specific to FQIS in
                                                 high-voltage hot short onto non-tank-                   25.981(a)(3)) (http://www.faa.gov/                    time to support the NPRM, noting that
                                                 side circuits to cause non-intrinsically                regulations_policies/advisory_circulars/              they have provided service instructions
                                                 safe energy, voltage, or current levels to              index.cfm/go/document.information/                    to install FRM that the FAA has defined
                                                 be conducted into the fuel tanks. The                   documentID/73716)) require corrective                 as one method of compliance within the
                                                 latent-plus-one concern therefore still                 action for ‘‘known latent-plus-one                    NPRM (77 FR 12506, March 1, 2012).
                                                 exists even with the additional                         conditions’’ in both low- and high-                   While the FAA has the authority to
                                                 detection capabilities that exist in the                flammability tanks.                                   compel the manufacturer to provide a
                                                 Goodrich FQIS. We have determined                          We infer the commenter is requesting               solution specifically providing FQIS
                                                 this concern requires corrective action                 that we revise the proposed actions of                protection, in this case the FAA decided
                                                 in accordance with the SFAR 88                          the NPRM (77 FR 12506, March 1, 2012)                 to seek public comment on the NPRM
                                                 corrective action decision policy                       to apply to all fuel tanks. We disagree.              (77 FR 12506, March 1, 2012) before
                                                 discussed previously. We disagree with                  NATCA’s interpretation of the word                    deciding whether to take that action.
                                                 the request to revise this SNPRM to                     ‘‘known’’ appears to be different from                The FAA already requires the vast
                                                 eliminate any requirement for corrective                that intended by the FAA when the                     majority of passenger airplanes
                                                 action for airplanes equipped with a                    SFAR 88 decision criteria were                        registered in the U.S. to be equipped
                                                 Goodrich FQIS because we have                           developed and implemented. For low-                   with FRM, and since we defined
                                                 determined that an unsafe condition                     flammability fuel tanks, the FAA has                  incorporation of FRM as one method of
                                                 requiring corrective action exists on the               proposed that corrective action for                   compliance within the NPRM (77 FR
                                                 Goodrich FQIS-equipped airplanes even                   ‘‘latent-plus-one’’ issues be required                12506, March 1, 2012), and because
                                                 after considering the differences                       only in cases where the particular                    Boeing and Goodrich provided
                                                 between the Goodrich FQIS and the                       latent-plus-one scenario is known to                  information to show that a specific FQIS
                                                 original 757 system developed by                        have occurred on that particular design.              protection solution would have a per-
                                                 another manufacturer. We have not                       Where relevant design details are                     airplane cost similar to that of Boeing’s
                                                 changed this SNPRM regarding this                       significantly different, a condition that             FRM design solution, we have
                                                 issue.                                                  has occurred with one design is not                   determined there is no practical reason
                                                                                                         considered to be a ‘‘known’’ latent-plus-             to require the manufacturer to provide
                                                 Request To Clarify Affected Tanks                       one condition on another design simply                a corrective action specific to FQIS for
                                                    FedEx requested that we revise the                   because the same architectural                        passenger airplanes. Consideration of
                                                 NPRM (77 FR 12506, March 1, 2012) to                    vulnerability theoretically exists.                   the many comments on the NPRM (77
                                                 clarify that only the center fuel tank is                  In the case of AD 98–20–40,                        FR 12506, March 1, 2012) has resulted
                                                 affected. FedEx stated that the proposed                Amendment 39–10808 (63 FR 52147,                      in a revision of the FAA’s approach for
                                                 wording could be interpreted as                         September 30, 1998); and AD 99–03–04,                 cargo airplanes, leading to a
                                                 applying to all tanks.                                  Amendment 39–11018 (64 FR 4959,                       significantly different proposed AD. At
                                                    We agree to clarify the intent of this               February 2, 1999); we required                        this point we do expect the
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                                                 SNPRM. The FQIS wiring and related                      corrective action for all fuel tanks                  manufacturer to provide service
                                                 system components are to be modified                    because the details of those designs                  information for the proposed optional
                                                 to the extent necessary to prevent the                  were identical or very similar to the                 solution for cargo airplanes. We have,
                                                 development of an ignition source in the                details of the design that were                       however, decided not to further delay
                                                 center fuel tank due to FQIS failure                    considered to be the most likely cause                action on this issue by waiting for that
                                                 conditions. If modification of wing tank-               of the 1996 Model 747–100 accident.                   service information. The service
                                                 related components is necessary to                      The actions of AD 98–20–40 and AD                     information is expected to be released
                                                 prevent an ignition source in the center                99–03–04 are consistent with the intent               shortly after the issuance of a final rule.


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                                                                       Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                            9409

                                                 No change to this SNPRM is necessary                    from an additional single failure, it                 and for operators that must comply with
                                                 for this issue. If service information                  would still exceed the TARAM-                         the AD. This SNPRM, however, is not
                                                 becomes available before the final rule                 allowable risk level for individual flight            the appropriate forum to discuss
                                                 is issued, we might consider                            risk. This determination is consistent                potential enforcement action. We have
                                                 incorporating it into the AD.                           with the SFAR 88 corrective action                    not changed this SNPRM regarding this
                                                                                                         decision policy and TARAM policy. As                  issue.
                                                 Request for Information on
                                                                                                         discussed previously, we have added
                                                 Modifications                                                                                                 Boeing’s Planned Service Information
                                                                                                         new paragraph (h) in this SNPRM to
                                                    Icelandair requested more detailed                   allow the option of a periodic BITE
                                                 information on the specific                                                                                      Boeing stated that it will offer only
                                                                                                         check and partial wire separation for                 the Boeing FRM as a solution, if the AD
                                                 modifications that would need to be                     cargo airplanes.
                                                 performed to comply with the proposed                                                                         is issued as proposed. Boeing added that
                                                 requirements specified in the NPRM (77                  Request for Repetitive Inspections or                 it does not develop detailed cost
                                                 FR 12506, March 1, 2012), and asked if                  Replacement                                           estimates for design changes they do not
                                                 a related service bulletin was available.                  Oy Air Finland Ltd. stated that wires              intend to provide. Further, Boeing
                                                    Service information is available for                 within the fuel tank must remain in an                stated that it does not advocate FRM
                                                 incorporation of FRM approved by the                    undamaged condition and therefore                     installation on airplanes for which FRM
                                                 FAA as compliant with the FTFR rule                     requested that we revise the NPRM (77                 is not required under the FTFR rule
                                                 (73 FR 42444, July 21, 2008)                            FR 12506, March 1, 2012) to specify                   (‘‘Reduction of Fuel Tank Flammability
                                                 requirements of section 26.33(c)(1) of                  their repetitive inspection or                        in Transport Category Airplanes’’ (73 FR
                                                 the Federal Aviation Regulations (14                    replacement. The commenter provided                   42444, July 21, 2008)). Boeing proposed
                                                 CFR 26.33(c)(1)).                                       no justification.                                     no change to the NPRM (77 FR 12506,
                                                    As stated previously, we have revised                   We disagree with including specific                March 1, 2012). Boeing noted that a
                                                 the NPRM (77 FR 12506, March 1, 2012)                   requirements to periodically inspect or               requirement to install an FRM on the
                                                 to provide more specific information                    replace the wiring within the fuel tanks              affected airplanes could not be justified
                                                 about a less costly optional modification               because airworthiness limitations and                 in the cost-versus-benefit analysis
                                                 for cargo airplanes. Service information                existing maintenance practices are                    performed for the new FTFR rule, and
                                                 related to this modification is not                     already in place to monitor the                       therefore cannot be justified to address
                                                 currently available. We have not                        condition of in-tank wiring. This                     the unsafe condition identified by the
                                                 changed this SNPRM further regarding                    SNPRM would require installation of                   FAA.
                                                 this issue.                                             flammability reduction means or a                        We have provided the basis for this
                                                                                                         combination of periodic system checks                 SNPRM in response to ‘‘Request for
                                                 Request for Optional Modification
                                                                                                         (which would detect many types of                     Cost-Benefit Analysis’’ in this SNPRM.
                                                    Goodrich requested that we revise the                wiring defects or damage) and wire
                                                 NPRM (77 FR 12506, March 1, 2012) to                                                                          We emphasize, however, that this
                                                                                                         separation improvements, either of                    SNPRM does not require installation of
                                                 require or allow a modification to                      which would significantly reduce the
                                                 separate and shield the FQIS tank-side                                                                        a nitrogen generation system or other
                                                                                                         probability of a fuel tank explosion on               FRM. The actions specified in this
                                                 circuits from other wiring as corrective                a given airplane flight to an acceptable
                                                 action for the identified unsafe                                                                              SNPRM will correct a specific, known
                                                                                                         level. We have not changed this SNPRM
                                                 condition. Goodrich referred to its                                                                           unsafe condition with the FQIS. We
                                                                                                         regarding this issue.
                                                 discussion regarding the capability of                                                                        decided to propose this AD action
                                                 the Goodrich FQIS processor to isolate                  Request To Compel Issuance of Service                 without specific service information for
                                                 the tank-side circuits from the non-tank-               Information                                           the expected design solution
                                                 side circuits.                                             NATCA requested that we enforce                    specifically because Boeing has not to
                                                    We partially agree with the request.                 sections 21.99 and 183.63(d) of the                   date provided a design solution specific
                                                 We considered that method of                            Federal Aviation Regulations (14 CFR                  to FQIS. As a result of considering the
                                                 compliance and determined that the                      21.99 and 183.63(d)) and SFAR 88,                     comments to the NPRM (77 FR 12506,
                                                 benefit from that corrective action                     Amendment 21–78, and subsequent                       March 1, 2012), the FAA has identified
                                                 would be sufficient for cargo airplanes                 Amendments 21–82 and 21–83) (http://                  a less costly option for Model 757 cargo
                                                 when combined with regular FQIS                         rgl.faa.gov/Regulatory_and_Guidance_                  airplanes. We have asked Boeing to
                                                 checks using the previously mentioned                   Library%5CrgFAR.nsf/0/EEFB3F9445                      develop service information for that
                                                 built-in test capability. We disagree with              1DC06286256C93004F5E07?Open                           option, and Boeing has agreed. Since the
                                                 allowing the proposed alternative for                   Document) to obtain necessary service                 FAA already requires the vast majority
                                                 passenger airplanes that are not                        information from design approval                      of passenger airplanes registered in the
                                                 equipped with FRM because the level of                  holders. NATCA noted that EASA                        U.S. to be equipped with FRM and we
                                                 risk reduction achieved from that                       cannot ‘‘issue ADs’’ (that is, EASA may               defined incorporation of FRM as one
                                                 alternative corrective action would not                 not be able to adopt the FAA AD per se)               method of compliance within the NPRM
                                                 provide a sufficient risk reduction for                 if specific service information is not                (77 FR 12506, March 1, 2012), and
                                                 those airplanes. Even when the built-in                 identified. NATCA expressed concern                   because Boeing and Goodrich provided
                                                 test capability is periodically exercised,              that other civil aviation authorities may             information to show that a specific FQIS
                                                 there will still be a significant latency               take a similar position.                              protection solution would have a per-
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                                                 period for some in-tank failures. The                      We partially agree with the request.               airplane cost similar to that of Boeing’s
                                                 risk on the flights where those failures                We agree that the cited regulations are               FRM design solution, we have
                                                 exist and where flammable conditions                    relevant in setting requirements for                  determined there is no practical reason
                                                 exist in the fuel tank is considered to be              action by design approval holders when                to require the manufacturer to provide
                                                 excessive for passenger airplanes,                      we have identified an unsafe condition.               a corrective action specific to FQIS for
                                                 because it results from a single                        We also recognize that issuance of an                 passenger airplanes. We have not
                                                 additional failure (those flights would                 AD without service information creates                further changed this SNPRM regarding
                                                 not be fail-safe). Even if it did not result            significant issues for regulatory agencies            this issue.


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                                                 9410                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 Request To Extend Compliance Time                       inerting systems for center fuel tanks,               directly affected the applicability of this
                                                 Pending Issuance of Service                             and the FAA was working with industry                 SNPRM, and implemented the FTFR
                                                 Information                                             to develop a practical nitrogen                       rule. Now that we are proposing action
                                                    A4A requested that we revise the                     generation system for new production                  for the affected airplanes, we must
                                                 NPRM (77 FR 12506, March 1, 2012) to                    and retrofit installations on transport               consider the ability of industry to
                                                 extend the compliance time from 60                      airplanes. The FAA was also planning                  develop an appropriate design change
                                                 months to ‘‘a 96-month compliance                       to propose a new rule requiring those                 and incorporate it on all affected
                                                 period that commences one year after                    systems to be installed on new and                    airplanes; we find that it is not practical
                                                 the effective date of the AD’’—for a total              existing airplanes, as recommended by                 for industry to respond to this AD in
                                                 compliance time of 9 years. A4A noted                   the NTSB. The FAA recognized that, if                 only 3 years. We have therefore not
                                                 that SFAR 88 (Special Federal Aviation                  such a system was installed on a given                reduced the compliance time in this
                                                                                                         set of airplanes, the unsafe condition                SNPRM.
                                                 Regulation No. 88 (‘‘SFAR 88,’’
                                                                                                         determination for the center fuel tank
                                                 Amendment 21–78, and subsequent                                                                               Request To Revise Cost Estimate Based
                                                                                                         latent-plus-one would be addressed due
                                                 Amendments 21–82 and 21–83) (http://                                                                          on New Data
                                                                                                         to the modified center fuel tank meeting
                                                 rgl.faa.gov/Regulatory_and_Guidance_                                                                             Boeing requested that we revise the
                                                                                                         the conditions for a low flammability
                                                 Library%5CrgFAR.nsf/0/EEFB3F94                                                                                cost estimate specified in the NPRM (77
                                                                                                         fuel tank after installation of a nitrogen
                                                 451DC06286256C93004F5E07?Open                                                                                 FR 12506, March 1, 2012) because the
                                                                                                         generation system.
                                                 Document)) required design solutions                       The FAA therefore decided to defer                 actual cost to develop and implement a
                                                 for non-compliant designs to be                         addressing the FQIS latent-plus-one                   design change to fully address the FQIS
                                                 provided by December 6, 2002, and                       issue on the affected airplanes until                 latent-plus-one failure conditions would
                                                 considered that the absence of service                  after the outcome of the FTFR                         be significantly higher. Boeing
                                                 information reflects a failure of                       rulemaking process. Now that the                      estimated in their comment that the cost
                                                 communication and coordination,                         rulemaking process is complete and the                to develop and implement a transient
                                                 presumably between the FAA and                          safety enhancement provided by the                    suppression unit design for Model 757
                                                 Boeing. A4A was concerned that                          FTFR rule (73 FR 42444, July 21, 2008)                airplanes would be about the same as
                                                 Boeing’s declaration that it does not                   has been limited to certain airplanes (14             the cost of Boeing’s FRM provided for
                                                 intend to develop a design solution                     CFR part 121, 125, and 129 passenger                  the airplanes affected by the FTFR rule
                                                 other than its existing nitrogen                        airplanes), the FAA is addressing the                 (73 FR 42444, July 21, 2008): in excess
                                                 generation system indicates that the                    FQIS latent-plus-one unsafe conditions                of $300,000 per airplane for airplanes
                                                 development of any other design                         on the airplanes that are not required to             equipped with the early FQIS design,
                                                 solution would be technically                           receive the safety enhancement of the                 and in excess of $200,000 per airplane
                                                 challenging and time consuming. A4A                     FTFR rule. This history was discussed                 for airplanes equipped with a Goodrich
                                                 also cited the implementation of the                    in detail in the NPRM (77 FR 12506,                   FQIS.
                                                 requirements of part 26 of the Federal                  March 1, 2012) and in the preamble for                   In a subsequent meeting initiated by
                                                 Aviation Regulations (14 CFR part 26) as                the FTFR rule.                                        the FAA to obtain more detail on this
                                                 an example of the FAA underestimating                      We disagree with extending the                     cost estimate, Boeing provided a higher
                                                 the costs and time required to develop                  compliance time to 9 years. Service                   cost estimate than they provided in their
                                                 design solutions.                                       information to support the modification               written comment. However, in
                                                    We partially agree with the request to               portion of the option for cargo airplanes             subsequent discussions with Boeing as
                                                 extend the compliance time. While we                    is expected to be available shortly after             part of developing this SNPRM, Boeing
                                                 agree to provide additional time for                    the final rule is issued. The service                 indicated that they were working on an
                                                 manufacturers to develop service                        information for the inspection portion of             isolation-based design alternative to the
                                                 information, we acknowledge that                        that option and the FRM option is                     FAA’s proposed modification option for
                                                 service information is not likely to be                 already released. We have determined                  the cargo airplanes that would likely be
                                                 available until several months after the                that a compliance time extension to 72                significantly less costly than the FAA’s
                                                 final rule is issued. We disagree with                  months for the modification will give                 proposed cargo airplane option of
                                                 the assertion that the delay in proposing               adequate time for manufacturers to                    partial wire separation.
                                                 an AD to address the FQIS latent-plus-                  complete the remaining service                           We partially agree with the
                                                 one unsafe conditions on several                        information and for operators to                      commenter. We agree to revise the cost
                                                 transport airplane models reflects a                    complete the modification.                            estimate because both Boeing and one of
                                                 failure to communicate and coordinate                      We have revised the compliance time                Boeing’s affected FQIS vendors
                                                 with design approval holders.                           in this SNPRM to 72 months after the                  provided similar cost estimates that
                                                    In 2003, the FAA held a series of AD                 effective date of the AD.                             were higher than the estimates made in
                                                 board meetings to decide which of the                                                                         the NPRM (77 FR 12506, March 1, 2012)
                                                 design areas identified in SFAR 88                      Request To Reduce Compliance Time                     by the FAA. We disagree to revise the
                                                 design reviews as non-compliant on                        NATCA requested that we reduce the                  cost estimate as Boeing proposed. We
                                                 Boeing airplanes would be classified as                 compliance time from 60 months to 36                  have received several inconsistent cost
                                                 unsafe conditions requiring AD action.                  months because of the time that has                   estimates from industry during the
                                                 The FQIS latent-plus-one issue was                      already passed to address this unsafe                 development of the FTFR rule (73 FR
                                                 identified as an unsafe condition for                   condition since its identification in                 42444, July 21, 2008), in their written
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                                                 high flammability fuel tanks at that time               2003.                                                 comments to the NPRM, and during
                                                 for several models, including the Model                   While we acknowledge the time that                  discussions of the FAA’s proposed
                                                 757. Several airplane models from other                 has passed since the identification of                alternative for cargo airplanes. We have
                                                 manufacturers were identified as having                 the unsafe condition identified in this               therefore provided a revised cost
                                                 similar issues. However, during that                    SNPRM, the FAA delayed taking action                  estimate for the originally proposed
                                                 same time period, the National                          for this issue while we developed the                 action based on input from Boeing’s
                                                 Transportation Safety Board (NTSB) had                  FTFR rule (73 FR 42444, July 21, 2008),               written comment and from the FQIS
                                                 recommended FAA action to require                       determined its applicability, which                   vendor. We also have considered that it


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                                                                       Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                             9411

                                                 is likely that aftermarket vendors may                  determined by the NTSB to be the most                 purpose of the cost estimate for
                                                 develop competing design solutions, as                  likely cause of the 1996 Model 747–100                passenger airplanes, we have assumed
                                                 has occurred for other similar ADs, and                 accident described in the NPRM.                       that the airplane will be upgraded to the
                                                 those solutions will likely cost less than              Because the latent-plus-one failure                   Goodrich FQIS if necessary, and any
                                                 the original manufacturer’s solutions.                  scenario was suspected of actually                    further modifications will be to only the
                                                    In addition, we have identified an                   having occurred on that system type, we               center fuel tank circuits or wiring. For
                                                 additional compliance option—with a                     determined that corrective action for all             the purpose of the additional proposed
                                                 different cost—for cargo airplanes. That                fuel tanks was appropriate. This                      cargo airplane option, we have provided
                                                 cost estimate is based on Model 757                     decision was consistent with the                      separate estimates for each design. For
                                                 service information that described a                    subsequently published FAA policy on                  cargo airplanes equipped with the early
                                                 very similar modification. We have used                 SFAR 88 AD decision criteria (section                 757 FQIS design, we have assumed that
                                                 the work-hour estimate from that service                25.981(a)(3) of the Federal Aviation                  additional isolation of some main fuel
                                                 bulletin, increased the work-hour                       Regulations (14 CFR 25.981(a)(3)))                    tank wiring will be required. It is not
                                                 estimate by 20 percent to account for                   (http://www.faa.gov/regulations_                      necessary to change the proposed
                                                 any unforeseen increases in the work,                   policies/advisory_circulars/index.cfm/                requirement itself in paragraph (g) of
                                                 and increased the parts prices to                       go/document.information/documentID/                   this SNPRM, which is very specific that
                                                 account for inflation and the potential                 73716)). Also, it was our understanding               protection is required for the center fuel
                                                 that additional parts may be needed.                    that the design of that FQIS was such                 tank.
                                                 Request To Revise Cost Estimate Based                   that, due to wiring interconnections
                                                                                                                                                               Request To Revise Cost Estimate To
                                                 on AD Scope                                             between fuel tanks, it was necessary to
                                                                                                                                                               Consider Long-Term Effect of AD
                                                                                                         protect the circuits for all fuel tanks in
                                                    Goodrich requested that, if the intent               order to achieve effective protection for                Goodrich asked whether the cost
                                                 of the NPRM (77 FR 12506, March 1,                      any one fuel tank.                                    estimate specified in the NPRM (77 FR
                                                 2012) is to protect all fuel tanks rather                  We have determined that the FQIS                   12506, March 1, 2012) considers the
                                                 than just the center fuel tank, we revise               used on earlier production Model 757                  expectation that the affected fleet will
                                                 the cost estimate of the NPRM                           airplanes has the same fuel tank                      be in operation for at least 20 more
                                                 accordingly. Goodrich stated that the                   interconnection issue, but that the                   years, and that a complete redesign of
                                                 cost estimate is based on three                         Goodrich system used on later                         the FQIS would need to be considered
                                                 assumptions: (1) That current                           production Model 757 airplanes does                   to ensure the availability of key FQIS
                                                 technology circuit isolation devices                    not have that issue. Since the cost                   electrical components. Goodrich stated
                                                 similar to those previously approved for                estimates provided by both Boeing and                 this concern could drive potential
                                                 other models would be acceptable, (2)                   Goodrich were based on design                         development costs higher.
                                                 that no further changes to airplane                     solutions that included upgrading to a                   We agree with the commenter’s
                                                 wiring would be required, and (3) that                  Goodrich FQIS, we assume that the                     assertion. We did consider that the
                                                 the design change would be required to                  level of circuit protection for the center            affected fleet will be in service for a
                                                 protect only the center fuel tank.                      fuel tank can be significantly increased              considerable period of time. In the cost
                                                 Goodrich noted that protection for all                  relative to the existing Goodrich design              estimate in the NPRM (77 FR 12506,
                                                 fuel tanks is required for the two similar              without having to further alter circuits              March 1, 2012), we assumed that the
                                                 ADs: AD 99–03–04, Amendment 39–                         or wiring for the main fuel tanks                     existing FQIS could be modified to meet
                                                 11018 (64 FR 4959, February 2, 1999),                   (beyond the alterations necessary to                  the intent of the AD. However,
                                                 for Model 737 airplanes; and AD 98–20–                  replace the FQIS with the Goodrich                    comments from Boeing and Goodrich
                                                 40, Amendment 39–10808 (63 FR                           FQIS).                                                led us to recognize that it was likely that
                                                 52147, September 30, 1998), for Model                      Because the latent-plus-one scenarios              operators of airplanes with the early 757
                                                 747 airplanes. Goodrich requested that                  for Model 757 airplanes equipped with                 FQIS design will likely need to be
                                                 we revise the cost estimate if the AD’s                 the Goodrich FQIS are classified as                   upgraded to the later Goodrich FQIS.
                                                 intent is to require protection for fuel                ‘‘theoretical’’ rather than ‘‘known to                The cost estimates used in this SNPRM
                                                 tanks other than the center fuel tank or                have occurred’’ under the FAA policy                  for the fully compliant FQIS option (as
                                                 if other wiring change requirements are                 on SFAR 88 AD decision criteria                       opposed to the newly added cargo
                                                 anticipated. Goodrich stated that the                   (section 25.981(a)(3) of the Federal                  airplane option) are based on the
                                                 cost specified in the NPRM should be                    Aviation Regulations (14 CFR                          estimates provided by Boeing and
                                                 estimated based on the actual design                    25.981(a)(3))) (http://www.faa.gov/                   Goodrich. We previously described
                                                 changes expected, rather than on                        regulations_policies/advisory_circulars/              changes to the cost estimate in this
                                                 previous AD actions.                                    index.cfm/go/document.information/                    SNPRM, but no further change is
                                                    We provide the following clarification               documentID/73716)), we have                           necessary regarding this issue.
                                                 of the intended scope of the NPRM (77                   determined in accordance with that
                                                 FR 12506, March 1, 2012) and the                        policy that the corrective action for                 Request To Explain Delay in
                                                 associated cost estimate regarding                      passenger airplanes must eliminate the                Rulemaking and Identify Planned
                                                 which fuel tanks are subject to the                     potential for all theoretical latent-plus-            SFAR 88 ADs
                                                 proposed requirements. AD 99–03–04,                     one scenarios to create an ignition                     A4A requested that we explain the
                                                 Amendment 39–11018 (64 FR 4959,                         source in the center fuel tank, which is              delay in rulemaking for this issue, and
                                                 February 2, 1999), and AD 98–20–40,                     classified under that policy as a high                identify any further planned SFAR 88
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                                                 Amendment 39–10808 (63 FR 52147,                        flammability fuel tank. The need to                   ADs. A4A asked why the NPRM (77 FR
                                                 September 30, 1998), affect FQIS                        modify the circuits or wiring for the                 12506, March 1, 2012) was issued
                                                 designs that are considered to have a                   main fuel tanks to achieve that intent                approximately 10 years after the
                                                 higher level of risk of a fuel tank                     will depend on the proposed design                    identification of the unsafe conditions
                                                 ignition source than the systems used                   solution and the existing configuration               and development of design solutions
                                                 on Model 757 airplanes. In addition,                    of the airplane.                                      was required to be completed under
                                                 those systems were identical or nearly                     As stated previously, we have revised              SFAR 88. A4A further asked that the
                                                 identical to the FQIS that was                          the cost estimate in this SNPRM. For the              FAA provide information on any other


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                                                 9412                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 designs that were already reviewed                      Request for Independent Review                        ‘‘equipped with a flammability
                                                 under SFAR 88, and provide industry                     Regarding Timeliness of AD                            reduction means (FRM) approved by the
                                                 with information regarding their                           NATCA requested an independent                     FAA. . . .’’ That exclusion does not
                                                 planned disposition.                                    review to identify and document how                   state that the installed equipment must
                                                    We have specifically discussed these                                                                       be operative. However, installed
                                                                                                         this issue was allowed to go
                                                 issues in the preamble to the FTFR rule                                                                       equipment is required to be operative by
                                                                                                         unaddressed for 16 years since the TWA
                                                 (73 FR 42444, July 21, 2008) and the                                                                          sections 121.628, 125.201, and 129.14 of
                                                                                                         accident and 9 years since SFAR 88
                                                 NPRM (77 FR 12506, March 1, 2012),                                                                            the Federal Aviation Regulations (14
                                                                                                         required the development of service
                                                 and explained the reasons for the delay                                                                       CFR 121.628, 14 CFR 125.201, and 14
                                                 in the response to ‘‘Request to Extend                  information. The commenter requested
                                                                                                         that the findings from that review be                 CFR 129.14) except as allowed by the
                                                 Compliance Time Pending Issuance of                                                                           MMEL and the operator’s approved
                                                 Service Information’’ in this SNPRM.                    published.
                                                                                                            We acknowledge that there have been                minimum equipment list (MEL).
                                                 We cannot provide additional                                                                                  Dispatch with an inoperative FRM
                                                 information on the results of design                    significant delays in addressing the
                                                                                                         issue that is the subject of this SNPRM.              under the MMEL is not prohibited by
                                                 reviews and the planned disposition of                                                                        the AD, and our intent is to allow such
                                                 issues identified in those design reviews               We are also fully aware of the events
                                                                                                         and factors that have led to those delays.            operation. We have not further changed
                                                 because that information is proprietary.                                                                      this SNPRM regarding this issue.
                                                 The FAA has not made available to the                   We infer that NATCA made the request
                                                 public an overall list of the specific                  to ensure that the public is aware of                 Request To Clarify Airplanes Excluded
                                                 product issues identified and the plans                 those events and factors. We have                     From Applicability
                                                 to address those issues, but operators                  described those events and factors in the                A4A requested that we revise the
                                                 can request the design review results                   NPRM (77 FR 12506, March 1, 2012)                     NPRM (77 FR 12506, March 1, 2012) to
                                                 from the manufacturers. We will likely                  and in the other comment responses                    clarify that airplanes equipped with
                                                 propose additional AD rulemaking, and                   included in this SNPRM, and therefore                 FRM before conversion to all-cargo
                                                 the public will be notified of those                    the FAA does not plan to conduct the                  operations are excluded from the
                                                 proposals via NPRMs. We have not                        proposed review. We have not changed                  proposed requirement to modify the
                                                 changed this SNPRM regarding this                       this SNPRM regarding this issue.                      FQIS.
                                                 issue.                                                  Request To Clarify Compliance Times                      We agree to provide clarification. The
                                                 Request To Explain Timing of NPRM                                                                             revised applicability of this SNPRM
                                                                                                            A4A requested that we revise the                   excludes airplanes for which operators
                                                 (77 FR 12506, March 1, 2012) and                        NPRM (77 FR 12506, March 1, 2012) to
                                                 Deficiencies of Affected Design                                                                               have installed FRM. No further change
                                                                                                         clarify that the compliance deadlines in              is necessary to this SNPRM regarding
                                                    FedEx requested that we explain what                 the AD prevail over the compliance                    this issue. As noted above, the FRM
                                                 is non-compliant about the affected                     deadlines in section 121.1117 of the                  must be operational with the exception
                                                 design and why we are proposing this                    Federal Aviation Regulations (14 CFR                  of any relief granted under MMEL
                                                 design change at this late date. FedEx                  121.1117) for any airplane for which the              provisions.
                                                 stated that Boeing and Goodrich                         operator has chosen to comply with the
                                                 determined in their safety reviews that                 AD by installing FRM.                                 Additional Change to NPRM (77 FR
                                                 only the FQIS densitometer was non-                        The proposed compliance times                      12506, March 1, 2012)
                                                 compliant.                                              reflect the desired interpretation of the               We have removed NOTE 1 of the
                                                    We agree to provide further                          commenter as they pertain to cargo                    NPRM (77 FR 12506, March 1, 2012).
                                                 explanation. This SNPRM addresses the                   airplanes and airplanes that are not                  The note was included only as reminder
                                                 question about the timing of this                       operated per part 121, part 125, or part              that maintenance and/or preventive
                                                 proposal under ‘‘Request to Extend                      129 of the Federal Aviation Regulations               maintenance under 14 CFR part 43 is
                                                 Compliance Time Pending Issuance of                     (14 CFR part 121, 14 CFR part 125, or                 permitted provided the maintenance
                                                 Service Information’’ in this SNPRM.                    14 CFR part 129). Passenger airplanes                 does not result in changing the AD-
                                                 Boeing and Goodrich did identify that                   operating under part 121, part 125, or                mandated configuration (reference 14
                                                 the densitometer of the Goodrich system                 part 129 of the Federal Aviation                      CFR 39.7).
                                                 had the potential for a single failure to               Regulations (14 CFR part 121, 14 CFR
                                                 cause an ignition source in a fuel tank.                part 125, or 14 CFR part 129) must meet               FAA’s Determination
                                                 That issue was addressed by AD 2009–                    the compliance deadlines established in                  We are proposing this SNPRM
                                                 06–20, Amendment 39–15857 (74 FR                        those operating rules. No change to this              because we evaluated all the relevant
                                                 12236, March 24, 2009). However, the                    SNPRM is necessary regarding this                     information and determined the unsafe
                                                 Boeing safety review and the FAA SFAR                   issue.                                                condition described previously is likely
                                                 88 AD Board also identified the                                                                               to exist or develop in other products of
                                                 potential for a failure in airplane wiring              Request To Clarify Master Minimum
                                                                                                         Equipment List (MMEL) Relief                          the same type design. Certain changes
                                                 outside the fuel tank or in the FQIS                                                                          described above expand the scope of the
                                                 processor unit that, combined with a                      A4A requested that we revise the                    NPRM (77 FR 12506, March 1, 2012). As
                                                 pre-existing latent failure of wiring or                NPRM (77 FR 12506, March 1, 2012) to                  a result, we have determined that it is
                                                 certain types of probe contamination                    clarify that the MMEL relief provided                 necessary to reopen the comment period
                                                 inside the fuel tank, could cause an                    for the Boeing NGS also applies to                    to provide additional opportunity for
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                                                 ignition source. These identified failure               airplanes for which the operator has                  the public to comment on this SNPRM.
                                                 combinations were considered to be                      chosen to comply with the AD by
                                                 non-compliant with section 25.901(c) of                 installing an FRM such as the Boeing                  Proposed Requirements of the SNPRM
                                                 the Federal Aviation Regulations (14                    NGS.                                                    This SNPRM would require
                                                 CFR 25.901(c)) and section 25.981 of the                  We acknowledge the commenter’s                      modifying the FQIS wiring or fuel tank
                                                 Federal Aviation Regulations (14 CFR                    concern. The revised applicability                    systems to prevent development of an
                                                 25.981). We have not changed this                       statement in paragraph (c) of this                    ignition source inside the center fuel
                                                 SNPRM regarding this issue.                             SNPRM excludes airplanes that are                     tank.


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                                                                              Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules                                                             9413

                                                 Costs of Compliance                                                    This estimate includes 148 cargo                         following costs to comply with this
                                                    We estimate that this proposed AD                                   airplanes and 19 non-air-carrier                         proposed AD:
                                                 affects 167 airplanes of U.S. registry.                                passenger airplanes. We estimate the

                                                                                Action                                                            Labor cost                            Parts cost          Cost per product

                                                                                                        Estimated Costs—Basic Proposed Requirement for All Airplanes

                                                 Fully correct FQIS vulnerability to latent-plus-one                        1,200 work-hours × $85 per hour = $102,000 .....               $200,000    $302,000.
                                                   failure conditions.

                                                                                                                 Estimated Costs—Optional Actions for All Airplanes

                                                 Install FRM ............................................................   720 work-hours × $85 per hour = $61,200 ..........             $323,000    $384,200.

                                                                                                               Estimated Costs—Optional Actions for Cargo Airplanes

                                                 Wire separation .....................................................      230 work-hours × $85 per hour = $19,550 ..........               $10,000   $29,550.
                                                 FQIS BITE check (required with wire separation                             1 work-hour × $85 per hour = $85 .......................               0   $85 per check (4 checks
                                                   option).                                                                                                                                              per year).



                                                    Existing regulations already require                                the relationship between the national                    (a) Comments Due Date
                                                 that air-carrier passenger airplanes be                                Government and the States, or on the                       We must receive comments by April 24,
                                                 equipped with FRM by December 26,                                      distribution of power and                                2015.
                                                 2017. We therefore assume that the FRM                                 responsibilities among the various                       (b) Affected ADs
                                                 installation specified in paragraph (g) of                             levels of government.
                                                                                                                                                                                   None.
                                                 this SNPRM would be done on only the                                     For the reasons discussed above, I
                                                 19 affected non-air-carrier passenger                                  certify this proposed regulation:                        (c) Applicability
                                                 airplanes, for an estimated passenger                                                                                              This AD applies to The Boeing Company
                                                                                                                          (1) Is not a ‘‘significant regulatory
                                                 fleet cost of $5,738,000. We also assume                                                                                        Model 757–200, –200PF, –200CB, and –300
                                                                                                                        action’’ under Executive Order 12866,                    series airplanes; certificated in any category;
                                                 that the operators of the 148 affected
                                                 cargo airplanes would choose the less                                    (2) Is not a ‘‘significant rule’’ under                except airplanes equipped with a
                                                 costly actions specified in paragraph (h)                              the DOT Regulatory Policies and                          flammability reduction means (FRM)
                                                                                                                        Procedures (44 FR 11034, February 26,                    approved by the FAA as compliant with the
                                                 of this AD, at an estimated cost of                                                                                             Fuel Tank Flammability Reduction (FTFR)
                                                 $4,373,400 for the wire separation                                     1979),
                                                                                                                                                                                 rule (73 FR 42444, July 21, 2008)
                                                 modification, plus $50,320 annually for                                  (3) Will not affect intrastate aviation                requirements of section 25.981(b) or section
                                                 the BITE checks.                                                       in Alaska, and                                           26.33(c)(1) of the Federal Aviation
                                                                                                                          (4) Will not have a significant                        Regulations (14 CFR 25.981(b) or 14 CFR
                                                 Authority for This Rulemaking                                                                                                   26.33(c)(1)).
                                                                                                                        economic impact, positive or negative,
                                                    Title 49 of the United States Code                                  on a substantial number of small entities                (d) Subject
                                                 specifies the FAA’s authority to issue                                 under the criteria of the Regulatory                       Joint Aircraft System Component (JASC)
                                                 rules on aviation safety. Subtitle I,                                  Flexibility Act.                                         Code 7397: Engine fuel system wiring.
                                                 section 106, describes the authority of
                                                 the FAA Administrator. ‘‘Subtitle VII:                                 List of Subjects in 14 CFR Part 39                       (e) Unsafe Condition
                                                 Aviation Programs’’ describes in more                                    Air transportation, Aircraft, Aviation                    This AD was prompted by fuel system
                                                 detail the scope of the Agency’s                                                                                                reviews conducted by the manufacturer. We
                                                                                                                        safety, Incorporation by reference,                      are issuing this AD to prevent development
                                                 authority.                                                             Safety.
                                                    We are issuing this rulemaking under                                                                                         of an ignition source inside the center fuel
                                                 the authority described in Subtitle VII,                               The Proposed Amendment                                   tank caused by a latent in-tank failure
                                                                                                                                                                                 combined with electrical energy transmitted
                                                 Part A, Subpart III, Section 44701:                                                                                             into the center fuel tank via the fuel quantity
                                                 ‘‘General requirements.’’ Under that                                     Accordingly, under the authority
                                                                                                                        delegated to me by the Administrator,                    indicating system (FQIS) wiring due to a
                                                 section, Congress charges the FAA with                                                                                          single out-tank failure.
                                                 promoting safe flight of civil aircraft in                             the FAA proposes to amend 14 CFR part
                                                 air commerce by prescribing regulations                                39 as follows:                                           (f) Compliance
                                                 for practices, methods, and procedures                                                                                             Comply with this AD within the
                                                                                                                        PART 39—AIRWORTHINESS                                    compliance times specified, unless already
                                                 the Administrator finds necessary for                                  DIRECTIVES                                               done.
                                                 safety in air commerce. This regulation
                                                 is within the scope of that authority                                                                                           (g) Modification
                                                                                                                        ■ 1. The authority citation for part 39
                                                 because it addresses an unsafe condition                               continues to read as follows:                               Within 72 months after the effective date
                                                 that is likely to exist or develop on                                                                                           of this AD, modify the FQIS wiring or fuel
                                                 products identified in this rulemaking                                     Authority: 49 U.S.C. 106(g), 40113, 44701.           tank systems to prevent development of an
Rmajette on DSK2VPTVN1PROD with PROPOSALS




                                                 action.                                                                                                                         ignition source inside the center fuel tank,
                                                                                                                        § 39.13    [Amended]                                     using a method approved in accordance with
                                                 Regulatory Findings                                                    ■ 2. The FAA amends § 39.13 by adding                    the procedures specified in paragraph (i) of
                                                   We determined that this proposed AD                                  the following new airworthiness                          this AD.
                                                 would not have federalism implications                                 directive (AD):                                          (h) Optional Actions for Cargo Airplanes
                                                 under Executive Order 13132. This                                      The Boeing Company: Docket No. FAA–                        For airplanes used exclusively for cargo
                                                 proposed AD would not have a                                               2012–0187; Directorate Identifier 2011–              operations: As an option to the requirements
                                                 substantial direct effect on the States, on                                NM–094–AD.                                           of paragraph (g) of this AD, do the actions



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                                                 9414                  Federal Register / Vol. 80, No. 35 / Monday, February 23, 2015 / Proposed Rules

                                                 specified in paragraphs (h)(1) and (h)(2) of            AGENCY:  Office of Postsecondary                         If you use a telecommunications
                                                 this AD, using methods approved in                      Education, Department of Education.                   device for the deaf (TDD) or a text
                                                 accordance with the procedures specified in                                                                   telephone (TTY), call the Federal Relay
                                                                                                         ACTION: Proposed priorities,
                                                 paragraph (i) of this AD.
                                                                                                         requirements, selection criterion, and                Service (FRS), toll free, at 1–800–877–
                                                   (1) Within 6 months after the effective date
                                                 of this AD, record the existing fault codes             definitions.                                          8339.
                                                 stored in the FQIS processor and then do a                                                                    SUPPLEMENTARY INFORMATION:
                                                 BITE check (check of built-in test equipment)           SUMMARY:    The Assistant Secretary for                  Invitation to Comment: We invite you
                                                 of the FQIS, in accordance with the                     Postsecondary Education proposes                      to submit comments regarding this
                                                 Accomplishment Instructions of Boeing                   priorities, requirements, a selection                 notice. To ensure that your comments
                                                 Service Bulletin 757–28–0136, dated June 5,             criterion, and definitions under the First            have maximum effect in developing the
                                                 2014. If any fault codes are recorded prior to          in the World (FITW) Program. The
                                                 the BITE check or as a result of the BITE
                                                                                                                                                               notice of final priorities, requirements,
                                                                                                         Assistant Secretary may use these                     selection criterion, and definitions, we
                                                 check, before further flight, do all applicable         priorities, requirements, selection
                                                 repairs and repeat the BITE check until a                                                                     urge you to identify clearly the specific
                                                 successful test is performed with no faults
                                                                                                         criterion, and definitions for FITW                   proposed priority, requirement,
                                                 found, in accordance with Boeing Service                competitions in fiscal year (FY) 2015                 selection criterion or definition that
                                                 Bulletin 757–28–0136, dated June 5, 2014.               and later years. These priorities,                    each comment addresses.
                                                 Repeat these actions thereafter at intervals            requirements, selection criterion, and                   We invite you to assist us in
                                                 not to exceed 750 flight hours.                         definitions would enable the                          complying with the specific
                                                   (2) Within 72 months after the effective              Department to focus the FITW program                  requirements of Executive Orders 12866
                                                 date of this AD, modify the airplane by                 on identified barriers to student success             and 13563 and their overall requirement
                                                 separating FQIS wiring that runs between the            in postsecondary education and
                                                 FQIS processor and the center fuel tank,                                                                      of reducing regulatory burden that
                                                 including any circuits that might pass
                                                                                                         advance the program’s purpose to build                might result from these proposed
                                                 through a main fuel tank, from other airplane           evidence for what works in                            priorities, requirements, selection
                                                 wiring that is not intrinsically safe.                  postsecondary education through                       criterion, or definitions. Please let us
                                                                                                         development, evaluation, and                          know of any further ways we could
                                                 (i) Alternative Methods of Compliance
                                                                                                         dissemination of innovative strategies to             reduce potential costs or increase
                                                 (AMOCs)
                                                                                                         support students who are at risk of                   potential benefits while preserving the
                                                    (1) The Manager, Seattle Aircraft                    failure in persisting in and completing               effective and efficient administration of
                                                 Certification Office (ACO), FAA, has the
                                                                                                         their postsecondary programs of study.                the program.
                                                 authority to approve AMOCs for this AD, if
                                                 requested using the procedures found in 14              DATES: We must receive your comments                     During and after the comment period,
                                                 CFR 39.19. In accordance with 14 CFR 39.19,             on or before March 25, 2015.                          you may inspect all public comments
                                                 send your request to your principal inspector           ADDRESSES: Submit your comments                       about this notice by accessing
                                                 or local Flight Standards District Office, as           through the Federal eRulemaking Portal                Regulations.gov. You may also inspect
                                                 appropriate. If sending information directly
                                                                                                         or via postal mail, commercial delivery,              the comments in person in room 6164,
                                                 to the manager of the ACO, send it to the                                                                     1990 K. St. NW., Washington, DC
                                                 attention of the person identified in                   or hand delivery. We will not accept
                                                                                                         comments submitted by fax or by email                 between the hours of 8:30 a.m. and 4:00
                                                 paragraph (j) of this AD. Information may be                                                                  p.m., Washington, DC time, Monday
                                                 emailed to: 9-ANM-Seattle-ACO-AMOC-                     or those submitted after the comment
                                                 Requests@faa.gov.                                       period. To ensure that we do not receive              through Friday of each week except
                                                    (2) Before using any approved AMOC,                  duplicate copies, please submit your                  Federal holidays. Please contact the
                                                 notify your appropriate principal inspector,            comments only once.                                   person listed under FOR FURTHER
                                                                                                                                                               INFORMATION CONTACT.
                                                 or lacking a principal inspector, the manager              • Federal eRulemaking Portal: Go to
                                                 of the local flight standards district office/                                                                   Assistance to Individuals with
                                                                                                         www.regulations.gov to submit your
                                                 certificate holding district office.                                                                          Disabilities in Reviewing the
                                                                                                         comments electronically. Information
                                                 (j) Related Information
                                                                                                                                                               Rulemaking Record: On request we will
                                                                                                         on using Regulations.gov, including
                                                                                                                                                               provide an appropriate accommodation
                                                    For more information about this AD,                  instructions for accessing agency
                                                                                                                                                               or auxiliary aid to an individual with a
                                                 contact Jon Regimbal, Aerospace Engineer,               documents, submitting comments, and
                                                 Propulsion Branch, ANM–140S, FAA, Seattle
                                                                                                                                                               disability who needs assistance to
                                                                                                         viewing the docket, is available on the
                                                 Aircraft Certification Office (ACO), 1601 Lind                                                                review the comments or other
                                                                                                         site under ‘‘Are you new to the site?’’
                                                                                                                                                               documents in the public rulemaking
                                                 Avenue SW., Renton, Washington 98057–                      • Postal Mail, Commercial Delivery,
                                                 3356; phone: 425–917–6506; fax: 425–917–                                                                      record for this notice. If you want to
                                                                                                         or Hand Delivery: If you mail or deliver
                                                 6590; email: jon.regimbal@faa.gov.                                                                            schedule an appointment for this type of
                                                                                                         your comments about these proposed
                                                   Issued in Renton, Washington, on                                                                            accommodation or auxiliary aid, please
                                                                                                         regulations, address them to Frank
                                                 December 18, 2014.                                                                                            contact the person listed under FOR
                                                                                                         Frankfort, U.S. Department of
                                                 Jeffrey E. Duven,                                                                                             FURTHER INFORMATION CONTACT.
                                                                                                         Education, 1990 K Street NW., Room                       Purpose of Program: Earning a
                                                 Manager, Transport Airplane Directorate,                6166, Washington, DC 20006.
                                                 Aircraft Certification Service.                                                                               postsecondary degree or credential is a
                                                                                                            Privacy Note: The Department’s
                                                                                                                                                               prerequisite for the growing jobs of the
                                                 [FR Doc. 2015–03540 Filed 2–20–15; 8:45 am]             policy is to make all comments received
                                                                                                                                                               new economy and the clearest pathway
                                                 BILLING CODE 4910–13–P                                  from members of the public available for
                                                                                                                                                               to the middle class. Average earnings of
                                                                                                         public viewing in their entirety on the
                                                                                                                                                               college graduates are almost twice as
                                                                                                         Federal eRulemaking Portal at
                                                                                                                                                               high as that of workers with only a high
Rmajette on DSK2VPTVN1PROD with PROPOSALS




                                                 DEPARTMENT OF EDUCATION                                 www.regulations.gov. Therefore,
                                                                                                                                                               school diploma and, over this decade,
                                                                                                         commenters should be careful to
                                                 34 CFR Chapter VI                                                                                             employment in jobs requiring education
                                                                                                         include in their comments only
                                                                                                                                                               beyond a high school diploma will grow
                                                                                                         information that they wish to make
                                                 Proposed Priorities, Requirements,                                                                            more rapidly than employment in jobs
                                                                                                         publicly available.
                                                 Selection Criterion, and Definitions—                                                                         that do not.1
                                                                                                         FOR FURTHER INFORMATION CONTACT:
                                                 First in the World Program
                                                                                                         Frank Frankfort. Telephone: (202) 502–                 1 Carnavale, A., Smith, N., Strohl, J., Help

                                                 CFDA Numbers: 84.116F and 84.116X                       7513 or email: frank.frankfort@ed.gov.                Wanted: Projections of Jobs and Education



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Document Created: 2015-12-18 13:28:37
Document Modified: 2015-12-18 13:28:37
CategoryRegulatory Information
CollectionFederal Register
sudoc ClassAE 2.7:
GS 4.107:
AE 2.106:
PublisherOffice of the Federal Register, National Archives and Records Administration
SectionProposed Rules
ActionSupplemental notice of proposed rulemaking (NPRM); reopening of comment period.
DatesWe must receive comments on this SNPRM by April 24, 2015.
ContactJon Regimbal, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917- 6506; fax: 425-917-6590; email: [email protected]
FR Citation80 FR 9400 
RIN Number2120-AA64
CFR AssociatedAir Transportation; Aircraft; Aviation Safety; Incorporation by Reference and Safety

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