81_FR_19537 81 FR 19472 - Airworthiness Directives; The Boeing Company Airplanes

81 FR 19472 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 65 (April 5, 2016)

Page Range19472-19482
FR Document2016-07150

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. This AD was prompted by fuel system reviews conducted by the manufacturer. This AD requires modifying the fuel quantity indication system (FQIS) wiring to prevent development of an ignition source inside the center fuel tank. We are issuing this AD to prevent ignition sources inside the center fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

Federal Register, Volume 81 Issue 65 (Tuesday, April 5, 2016)
[Federal Register Volume 81, Number 65 (Tuesday, April 5, 2016)]
[Rules and Regulations]
[Pages 19472-19482]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-07150]


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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; 
Amendment 39-18452; AD 2016-07-07]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
The Boeing Company Model 757 airplanes. This AD was prompted by fuel 
system reviews conducted by the manufacturer. This AD requires 
modifying the fuel quantity indication system (FQIS) wiring to prevent 
development of an ignition source inside the center fuel tank. We are 
issuing this AD to prevent ignition sources inside the center fuel 
tank, which, in combination with flammable fuel vapors, could result in 
a fuel tank explosion and consequent loss of the airplane.

DATES: This AD is effective May 10, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 10, 
2016.

[[Page 19473]]


ADDRESSES: For service information identified in this final rule, 
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 AD, the regulatory evaluation, any comments received, and 
other information. The address for the Docket Office (phone: 800-647-
5527) is Docket Management Facility, U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE., Washington, DC 20590.

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: 

Discussion

    We issued a supplemental notice of proposed rulemaking (SNPRM) to 
amend 14 CFR part 39 by adding an AD that would apply to certain The 
Boeing Company Model 757 airplanes. The SNPRM published in the Federal 
Register on February 23, 2015 (80 FR 9400) (``the SNPRM''). We preceded 
the SNPRM with a notice of proposed rulemaking (NPRM) that 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. The NPRM was prompted by fuel system 
reviews conducted by the manufacturer. The SNPRM proposed to revise the 
applicability, including alternative actions for cargo airplanes, and 
extend the compliance time. We are issuing this AD 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.

Record of Ex Parte Communication

    In preparation of AD actions such as NPRMs and immediately adopted 
rules, it is the practice of the FAA to obtain technical information 
and information on the operational and economic impact from design 
approval holders and aircraft operators. We discussed certain issues 
related to this final rule in a meeting held December 1, 2015, with 
Airlines for America (A4A) and other members of the aviation industry. 
This final rule addresses the issues discussed during that meeting that 
are relevant to this final rule. A summary of this meeting can be found 
in the rulemaking docket at http://www.regulations.gov by searching for 
and locating Docket No. FAA-2012-0187.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the SNPRM and 
the FAA's response to each comment.

Request To Withdraw SNPRM: New Certification Requirements for 
Flammability Reduction Means (FRM) Unwarranted

    A4A, representing U.S. cargo operators, stated that the FAA intends 
to issue rulemaking requiring U.S. cargo operators to do additional 
fuel safety modifications to meet the latest aircraft certification 
requirements.
    We infer that A4A considers that requiring airplanes to meet the 
latest certification requirements is not warranted and that the SNPRM 
should therefore be withdrawn. We assume that by ``the latest aircraft 
certification requirements,'' A4A is referring to the relatively new 
requirements for FRM contained in 14 CFR part 125.
    We do not agree that the SNPRM should be withdrawn. This AD is not 
specifically intended to require that the affected airplanes meet the 
flammability requirements of 14 CFR part 125. It is instead intended to 
address an unsafe condition as required by 14 CFR part 39 identified by 
the FAA under the policy contained in the FAA's Special Federal 
Aviation Regulation No. 88 (14 CFR part 21, SFAR 88) AD decision policy 
(Policy Memorandum ANM-100-2003-112-15) (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/DC94C3A46396950386256D5E006AED11?OpenDocument&Highlight=anm-100-2003-112-15), dated February 25, 2003, and the FAA's 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). 
The FAA determined that installing FRM that meets 14 CFR part 125 would 
be one acceptable way to address the identified unsafe condition, so 
airplanes on which such a modification was incorporated were excluded 
from the applicability of the SNPRM. Other modifications identified 
later in this discussion are available as alternative actions to 
installing FRM for certain operations. We have determined it is 
necessary to proceed with issuance of this final rule.

Request To Withdraw SNPRM: Intrusive, Expensive, Unnecessary

    A4A stated that Airbus and Boeing have indicated to them that the 
service bulletins for the wire separation modification that is part of 
the cargo airplane alternative actions will be intrusive and expensive 
and will not significantly improve safety. A4A stated that the safety 
analyses performed by the aircraft manufacturers do not classify the 
proposed modifications as safety critical. A4A noted that those service 
bulletins will not be issued as ``Alert'' service bulletins. 
Additionally, A4A stated that foreign regulatory authorities, aircraft 
manufacturers, and airlines do not support that a safety issue remains.
    We infer that A4A is requesting that we withdraw the SNPRM because 
the airplane manufacturers have determined that an unsafe condition 
does not exist and the SNPRM will not significantly improve safety. We 
do not agree that the SNPRM should be withdrawn. We acknowledge that 
Boeing does not consider the condition associated with FQIS on these 
airplanes to be unsafe. We disagree with Boeing's assertions, for the 
reasons discussed extensively in our response to Boeing's similar 
comment in the SNPRM, under ``Request to Withdraw NPRM (77 FR 12506, 
March 1, 2012): Unjustified by Risk.'' We have determined that it is 
necessary to proceed with issuance of this final rule.

[[Page 19474]]

Request To Withdraw SNPRM: Global Economic Disadvantage to U.S. 
Operators

    A4A does not expect that foreign regulators will require 
modification of affected foreign-registered aircraft, and stated that 
the competitive position of U.S. cargo operators will be harmed as a 
result. A4A stated that foreign regulatory agencies did not mandate 
retrofit of FRM for cargo airplanes, and therefore A4A did not expect 
that those authorities will mandate FQIS changes for their operators. 
A4A's comment made reference to documents published by the European 
Aviation Safety Agency (EASA), the Civil Aviation Authority of China 
(CAAC), and the Japan Civil Aviation Bureau (JCAB) as evidence that 
those agencies are not planning action to address any unsafe condition 
associated with FQIS.
    We infer that A4A is requesting that we withdraw the NPRM because 
other foreign regulatory agencies have determined that an unsafe 
condition does not exist with regard to FQIS as addressed by the 
proposed AD.
    We were unable to examine the EASA document A4A attempted to 
reference because the reference number was incomplete. We do not agree 
that the CAAC and JCAB documents indicate a position on the unsafe 
condition addressed by the SNPRM. Both of those documents simply state 
a requirement for existing type certificate holders to review fuel tank 
designs that is similar to the FAA's SFAR 88. Those documents do not 
state positions on any unsafe conditions or AD proposals identified by 
the FAA, the CAAC, or the JCAB.
    A4A stated that the U.S. air cargo industry is currently in an 
extremely competitive global market. Additional lower deck capacity on 
passenger aircraft, especially through Middle East hubs, has 
significantly increased the need for cargo industry capacity. Several 
cargo carriers have ceased operations, and many others have parked some 
aircraft. U.S. carriers compete directly with foreign cargo operators. 
A4A stated that any additional costs on U.S. cargo operators that are 
not incurred by foreign operators will make U.S. operators less 
competitive and will lead to the loss of jobs in the U.S.
    We infer that A4A is requesting that we withdraw the proposal to 
require corrective action on cargo airplanes because non-U.S. cargo 
operators will not be required to make similar modifications, and the 
FAA AD action would harm the competitive position of U.S. cargo 
operators, resulting in the loss of U.S. jobs.
    We do not agree to withdraw the SNPRM for corrective action on 
cargo airplanes. As part of the AD development process, the FAA works 
with the affected manufacturer to develop a cost estimate for the 
corrective actions in a proposed AD. The FAA considers all possible 
corrective actions proposed by a manufacturer in an attempt to minimize 
the cost burden on operators. In some cases the FAA even makes a 
specific suggestion to a manufacturer for a less costly alternative. In 
the end, the manufacturer is responsible for development of an 
appropriate corrective action.
    While the FAA attempts to minimize the costs associated with a 
required corrective action for a U.S. product, ultimately the FAA has 
the responsibility as the civil aviation authority (CAA) of the state 
of design to address unsafe conditions through AD action. Other CAAs 
overseeing foreign operators will typically apply the FAA AD or develop 
a similar AD for U.S. products operated under each CAA's jurisdiction. 
Other CAAs rely heavily on the knowledge and judgment of the CAA of the 
state of design to identify unsafe conditions and appropriate 
corrective actions for products of that state. The FAA is not aware at 
this time of any affected CAAs that do not plan to issue a 
corresponding mandate to address the unsafe condition associated with 
FQIS identified in the proposed AD. Even if such a situation occurs, 
the FAA would not use a foreign CAA's position as a justification for 
not addressing an unsafe condition identified by the FAA. While we 
acknowledge such a situation could harm the competitive position of a 
U.S. operator, we are still obligated by U.S. law and by international 
treaties to address the identified unsafe condition. We have determined 
that it is necessary to proceed with issuance of this final rule.

Request To Withdraw SNPRM: Costs of Compliance

    A4A stated that the proposed modifications are very costly, and 
noted that United Parcel Service (UPS) has estimated a total cost of 
$16 million for its fleet of four aircraft types that are potentially 
affected by the SNPRM and other similar planned ADs. A4A pointed out 
that U.S. cargo operators have already spent tens of millions of 
dollars on fuel tank safety improvements. UPS alone has spent $35.5 
million to comply with 51 SFAR 88 ADs on the four fleet types 
potentially affected. A4A noted that cargo operators already have 
recurring expenses for Enhanced Airworthiness Program for Airplane 
Safety (EAPAS) maintenance program tasks that continue to help ensure 
fuel tank safety. A4A added that cargo operators have already invested 
in improved and more expensive fuel tank component repair and overhaul 
processes.
    We infer that A4A is requesting that we withdraw the SNPRM because 
the costs of addressing previously identified fuel tank unsafe 
conditions has been high, and that the additional cost to address the 
FQIS latent-plus-one issue will also be high, with very little safety 
benefit.
    We do not agree to withdraw the SNPRM. We acknowledge that the 
total industry cost to address other fuel tank system unsafe conditions 
has been high. The SFAR 88 studies for Boeing airplanes identified 
several basic design deficiencies in lightning protection that could 
cause an ignition source in a fuel tank in the event of a lightning 
strike, and several issues with fuel pump systems and fuel valve 
systems where a single failure could result in an ignition source in a 
fuel tank. Fuel pump issues are suspected to have caused several fuel 
tank ignition events, so these issues were considered to be the highest 
priority for the development of corrective actions and related AD 
actions. The FAA considers the cost of addressing those issues to be 
clearly justified. Deficiencies in maintenance programs and 
inappropriate component repair actions that could lead to inadvertent 
significant increases in the risk of an ignition source in a fuel tank 
were also identified, and the cost of airworthiness limitations to 
address those issues is also considered to be justified.
    The SFAR 88 studies and the FAA's subsequent decision-making 
process identified FQIS vulnerability of Model 707, 727, 737, 747, 757, 
767, and 777 airplanes as an unsafe condition requiring corrective 
action. While the more recently designed of these airplane models have 
significant improvements in FQIS design details, they all have similar 
FQIS design architecture with respect to the identified failure 
scenario. That architecture is vulnerable to a combination of a latent 
in-tank wiring failure and a subsequent wiring failure outside of the 
tank that connects a high power source to the FQIS tank circuit 
creating an ignition source in a fuel tank. This failure combination 
was determined by the National Transportation Safety Board (NTSB) to 
have been the most likely cause of the Model 747 fuel tank explosion 
accident

[[Page 19475]]

off Long Island in 1996. NTSB Safety Recommendation A-98-038 (http://www.ntsb.gov/about/employment/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-98-038) recommended that the FAA require that 
FQIS wiring on all airplane models that have similar wiring 
installations be separated and shielded to the maximum extent possible.
    The FAA issued 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); to address this issue on early Model 747 and Model 
737 airplanes, respectively, which used the same FQIS as the accident 
airplane. The FAA subsequently (in 2003) determined that this same 
architectural vulnerability was an unsafe condition for high 
flammability fuel tanks on all Boeing jet transports existing at that 
time. This determination was consistent with the published FAA policy 
for SFAR 88 corrective actions and with the current FAA TARAM 
guidelines for identification of unsafe conditions on transport 
airplanes.
    The FAA deferred acting on this unsafe condition until after the 
FRM rulemaking activity was complete because introduction of FRM had 
the potential to change the classification of many of the affected fuel 
tanks to low flammability. When the final decision for the FRM rule did 
not include a requirement for FRM on all airplanes, the FAA resumed the 
planned actions to address the identified FQIS unsafe condition on the 
airplanes that were not required to have FRM.
    The FAA considers the safety benefit of the SNPRM to be significant 
for both passenger and cargo airplanes. We estimate that the 
installation of compliant FRM will provide approximately an order of 
magnitude reduction in the risk of a fuel tank explosion on anticipated 
flights with a latent failure of an FQIS circuit in the center fuel 
tank. We estimate that the periodic BITE checks in the cargo airplane 
alternative actions will result in a 75- to 90-percent reduction in the 
number of flights that operate with a latent in-tank failure that makes 
them vulnerable to a single additional wiring hot short failure 
creating an ignition source in the center fuel tank. We estimate that 
the proposed wire separation modification in the cargo airplane 
alternative actions will reduce the risk of a hot short (and a 
resultant ignition source) on flights that have a latent in-tank 
failure by 50 to 75 percent. This estimated reduction in the risk on 
anticipated flights with a latent in-tank failure is sufficient to 
reduce the risk below the FAA's TARAM individual flight risk guideline 
level for urgent action. As discussed below in our response to 
``Request to Remove Alternative Actions for Cargo Airplanes,'' we 
determined that further changes to further reduce the risk below the 
TARAM individual flight risk corrective action guideline of 1 in 10 
million per flight hour would significantly increase the costs of 
compliance and are not necessary to adequately address the unsafe 
condition. We have determined that it is necessary to proceed with 
issuance of this final rule.

Request To Withdraw SNPRM: Unsafe Condition Addressed by Previous 
Requirements

    A4A stated that there have been no fuel tank ignition incidents 
since the previously issued fuel tank safety ADs were implemented. A4A 
stated that this provides direct evidence that FAA projections for 
additional incidents were overstated and that SFAR 88 changes have 
worked. They further stated that no unsafe condition exists, asserting 
that service experience has shown that the fuel tank safety issues have 
been sufficiently addressed with significant previous modifications, 
recurring maintenance, controlled overhaul processes and repair 
processes, and maintenance program tasks.
    We infer that A4A is requesting that we withdraw the SNPRM because 
previously required actions have adequately addressed the need for 
improvements in fuel tank safety.
    We do not agree to withdraw the SNPRM. Until recently, fuel tank 
ignition incidents on U.S.- and European-manufactured transport 
airplanes have occurred roughly once every five to six years, with the 
most recent event in May 2006 (a Model 727 airplane in India in 2006, a 
Model 737 airplane in Thailand in 2001, a Model 747 airplane near New 
York in 1996, and a Model 737 airplane in the Philippines in 1991). It 
has now been ten years since the most recent event.
    We agree that a significant improvement in fuel tank safety has 
occurred due to actions that have reduced the potential for ignition 
sources associated with single failures of fuel pumps and fuel pump 
power systems. That improvement alone would be expected to increase the 
average interval between fuel tank ignition incidents to more than ten 
years. However, the fact that no incidents have occurred since 2006 is 
not statistically significant, and is not sufficient to predict that 
additional events will not occur. In addition, even assuming the 
average interval between events is significantly improved to the extent 
that the overall fleet risk is considered acceptable, we would still 
address unsafe conditions identified based on the published FAA policy 
for SFAR 88 corrective actions and the current FAA guidelines for 
identification of unsafe conditions on transport airplanes when the 
individual flight safety risk exceeds our guidelines, as in this case. 
We have determined that it is necessary to proceed with issuance of 
this final rule.

Request To Withdraw SNPRM: All Related NTSB Safety Recommendations 
Closed

    A4A stated that the NTSB previously issued the following safety 
recommendations related to flammability, wiring, and wiring 
maintenance:
     A-96-174--Preclude flammable fuel air mixtures in fuel 
tanks. Closed--Acceptable Action: FRM Rulemaking. Safety Recommendation 
A-96-174 can be found at http://www.ntsb.gov/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-96-174.
     A-98-038--Separation of FQIS wires to the max extent 
possible. Closed--Acceptable Action: SFAR 88 Rulemaking.
     A-98-039--Require surge protection systems for FQIS wires. 
Closed--Acceptable Action: SFAR 88 Rulemaking. Safety Recommendation A-
98-039 can be found at http://www.ntsb.gov/about/employment/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-98-039.
     A-00-106--Assess wiring criticality and separation. 
Closed--Acceptable Action: EAPAS/FTS Rulemaking. Safety Recommendation 
A-00-106 can be found at (http://www.ntsb.gov/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-00-106.
     A-00-108--Repair of potentially unsafe wiring conditions. 
Closed--Acceptable Action: EAPAS/FTS Rulemaking. Safety Recommendation 
A-00-108 can be found at http://www.ntsb.gov/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-00-108.
    A4A noted that all applicable NTSB safety recommendations are 
closed with acceptable actions taken by the FAA. A4A stated that none 
of the NTSB safety recommendations called for the FAA to address wire 
separation for the FQIS.
    We infer that A4A is requesting that we withdraw the SNPRM because 
the NTSB considers the overall fuel tank safety issue to be adequately 
addressed by previous actions.
    We do not agree to withdraw the SNPRM. A4A appears to have

[[Page 19476]]

misunderstood NTSB Safety Recommendation A-98-038 and the NTSB's 
acceptance of the FAA's response to that safety recommendation. NTSB 
Safety Recommendation A-98-038 specifically called for the FAA to 
require, in ``airplanes with fuel quantity indication system (FQIS) 
wire installations that are co-routed with wires that may be powered, 
the physical separation and electrical shielding of FQIS wires to the 
maximum extent possible.'' The NTSB classified that recommendation as 
``closed, acceptable action'' after the FAA stated that it would issue 
ADs to mandate FQIS protection on the high flammability tanks of 
aircraft on which the installation of FRM is not required by the Fuel 
Tank Flammability Reduction (FTFR) rule (73 FR 42444, July 21, 2008). 
The communications between the NTSB and the FAA on Safety 
Recommendation A-98-038 can be viewed at http://www.ntsb.gov/about/employment/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-98-038. We 
have determined that it is necessary to proceed with issuance of this 
final rule.

Request To Withdraw SNPRM: Unjustified by Risk Assessment

    A4A stated that the original equipment manufacturers (OEMs) and 
other regulatory agencies are having difficulty calculating the true 
safety value associated with the proposed FQIS AD. A4A stated that its 
position is that all the unsafe conditions have been mitigated, 
operationally and across industry, and all previous rules have been 
effective. A4A added that, in light of the operators' financial and 
technical investment to mitigate the unsafe conditions in all areas, 
the SNPRM is difficult to understand technically relative to the amount 
of mitigation that would be required, in light of a true risk 
assessment. A4A stated that the FAA is alone in believing that a safety 
issue still exists.
    We infer that A4A is requesting that we withdraw the SNPRM because 
it has not been justified by a risk assessment and because previously 
required actions have adequately addressed the need for improvements in 
fuel tank safety.
    We do not agree to withdraw the SNPRM. We provided a detailed 
response to similar comments and described the FAA's risk assessment in 
the SNPRM in the sections ``Request to Withdraw NPRM (77 FR 12506, 
March 1, 2012): Unjustified by Risk,'' ``Request to Withdraw NPRM (77 
FR 12506, March 1, 2012): Not Supported by Risk Analysis,'' and 
``Request to Withdraw NPRM (77 FR 12506, March 1, 2012): No Unsafe 
Condition,'' as well as in earlier paragraphs in this discussion. We 
have determined that it is necessary to proceed with issuance of this 
final rule.

Request To Remove Requirement for Corrective Actions for Cargo 
Airplanes

    A4A stated that the alternative wire separation modifications 
allowed for cargo airplanes would not meet the ``new design criteria.'' 
(We assume that A4A is referring to the wire separation requirements 
for repairs and modifications that are included in the fuel tank system 
airworthiness limitations required by recent ADs for the various Boeing 
models.) A4A stated that in the Model 757 service bulletin under 
development by Boeing, only about ``5 percent'' of FQIS wires can be 
separated from other systems by a distance of 2 inches, and that the 
majority of the wire bundle relocation will achieve only up to 0.5-inch 
spacing. A4A stated that because the wire separation requirements are 
not met, partial exemptions from the requirements of 14 CFR 25.981 are 
required to allow approval of these wire separation service bulletins. 
Based on the reduced separation distance and the need for exemptions, 
A4A considered the proposed wire separation requirements included in 
the cargo airplane alternative actions to be a symbolic gesture with no 
significant safety benefit, while at the same time being expensive and 
intrusive. A4A further stated that operators have reviewed the 
associated draft service bulletins and are concerned about the lack of 
a design target or adequate rationale for the actions proposed by the 
FAA. Finally, A4A stated that Boeing had stated to them that Boeing 
does not understand what design changes the FAA wants or why the FAA 
considers there to be a safety issue.
    We infer that A4A is requesting that we remove the alternative 
actions for a wire separation modification on cargo airplanes because 
A4A believes the wire separation actions associated with the cargo 
airplane alternative actions in the SNPRM would have no significant 
safety benefit since inadequate physical wire separation is provided.
    We do not agree to withdraw the SNPRM. A4A appears to have 
misunderstood the intent of the FQIS wire separation requirements added 
to the airworthiness limitations as a critical design configuration 
control limitation (CDCCL). The FQIS wire separation CDCCL provides a 
set of wire separation requirements that are intended to be used as a 
default when modifying or repairing an aircraft to ensure that the 
intended level of separation of the FQIS wiring from other wiring is 
maintained. The Model 757 CDCCL (28-AWL-05) contains a simple 2-inch 
separation requirement as originally proposed by Boeing. While Boeing 
has not proposed changes to the Model 757 FQIS wire separation CDCCL, 
the corresponding CDCCL (28-AWL-05) for Model 737-700, -800, and -900 
airplanes has numerous additional provisions approving other design 
approaches (typically combinations of wire sleeving and smaller 
separation distances) that Boeing or operators proposed and that the 
FAA approved. Each time wire separation configuration options were 
approved for Boeing, alternative CDCCL wording was approved as an AMOC 
with the AD that required the addition of the CDCCLs to operators' 
maintenance programs. A similar AMOC will be granted for the approved 
modifications to the FQIS for Model 757 airplanes.
    A4A also appears to have misunderstood the reason that exemptions 
would be required to allow approval of the cargo airplane wire 
separation modification. Lack of a full 2 inches of wire separation in 
all of the changed areas is not the reason an exemption is required. 
Rather, an exemption is required because the overall FQIS will not 
comply with 14 CFR 25.901(c) and 25.981(a)(3) due to the existing 
noncompliance of the unchanged areas of the system. Because those rules 
require a system-level safety analysis, we cannot find the changes to 
the system compliant if a noncompliance exists in the unchanged areas 
of the system.
    The proposed Boeing design uses sleeving over the wire bundles and 
extensive retention features to provide a level of wire protection 
similar to the protection that would be provided by a greater 
separation distance. The design measures are consistent with those 
previously approved by the FAA in the Model 737-700/800/900 CDCCL 
mentioned previously.
    We consider the safety benefit provided by the proposed cargo 
airplane alternative actions to be significant. The unsafe condition 
determination and the rationale and estimated safety benefit for the 
cargo airplane alternative actions were discussed extensively with 
Boeing in several meetings, and we consider that Boeing fully 
understands the FAA's position on each of those aspects of the 
proposal. The proposed requirement for a periodic check through the 
built-in test equipment (BITE) of the FQIS processor is intended to 
identify and result in corrective actions for the detectable fault 
conditions in the FQIS in-tank wiring. We estimated that this

[[Page 19477]]

proposed requirement will result in a 75- to 90-percent reduction in 
the number of flights that operate with a latent in-tank failure that 
makes them vulnerable to a single additional wiring hot short failure 
creating an ignition source in the center fuel tank. The proposed FQIS 
wire separation modification is intended to reduce the risk of a hot 
short of power onto center tank FQIS circuits by physically isolating 
the portions of those circuits that are outside of the tank in the 
areas where those circuits are most vulnerable to damage and most 
easily separated. We did not propose to require modifications of the 
wiring in the electrical racks or in the cockpit areas because of the 
difficulty involved in accessing and achieving additional wire 
separation in those areas, and in recognition that the FQIS processor 
provides some beneficial circuit isolation to protect against hot 
shorts in those areas. We estimated that the proposed wire separation 
modification would reduce the risk of a hot short on flights that have 
a latent in-tank failure by 50 to 75 percent. Those estimates were 
reviewed with Boeing, and Boeing did not disagree with those estimates. 
We have determined it is necessary to proceed with issuance of this 
final rule.

Request To Remove Alternative Actions for Cargo Airplanes

    Colin Edwards and an anonymous commenter made no explicit request 
to change the SNPRM, but objected to the proposed addition of 
alternative actions for cargo airplanes that would allow a design 
change that does not fully comply with the fuel tank system safety 
requirements of 14 CFR part 25 (14 CFR 25.981(a)(3)) to be used to 
address the unsafe condition. The commenters stated that it should not 
be acceptable to allow greater risk to exist on cargo airplanes than 
that allowed for passenger airplanes.
    We infer that the commenters propose the elimination of the 
proposed alternative corrective action for cargo airplanes. We disagree 
with this request. We determined that an acceptable level of safety 
would be provided for the affected cargo airplanes, and explained our 
position in depth in response to similar comments in the SNPRM. 
However, we will attempt to address the commenters' concerns by 
expanding on the explanation of our safety determination.
    When assessing potential unsafe conditions on transport airplanes 
to determine if corrective action is necessary, the FAA assesses the 
total risk to the affected fleet of airplanes exposed to the condition, 
and assesses the level of risk on individual airplanes within the 
fleet. The FAA's guidelines for assessing the total fleet risk related 
to the unsafe condition are slightly different for cargo and passenger 
airplanes due to operational usage differences. In this case, however, 
the total risk to the affected fleet is lower than the unsafe condition 
risk guidelines for both passenger and cargo airplanes. Total fleet 
risk is therefore not the risk assessment element driving the proposed 
actions.
    When assessing the level of risk on individual airplanes, the FAA 
considers the risk on the worst reasonably anticipated flights to 
ensure that the level of safety on each flight is acceptable. Our 
individual flight risk unsafe condition threshold is 1 x 10E-7 events 
(or a 1-in-10-million chance of a catastrophic event) per flight hour. 
In addition, the worst reasonably anticipated flights should not be 
vulnerable to a single failure that causes a fatal event, regardless of 
probability. There is no difference in the individual flight risk 
unsafe condition criteria for cargo airplanes and passenger airplanes 
because the operational differences are not considered in this risk 
calculation.
    In this case, we are concerned about a latent failure inside the 
fuel tank that, in combination with an electrical short circuit in FQIS 
wiring outside of the tank, could result in an electrical spark or arc 
in the tank. An electrical arc or spark in the fuel tank combined with 
flammable conditions in the fuel tank could result in a fuel tank 
explosion. The worst reasonably anticipated flights in this case are 
those that have both the latent failure and flammable conditions in the 
tank. The manufacturer's analysis indicates that a significant number 
of flights would be expected to occur with these conditions in the life 
of the affected fleet if no corrective action is taken. For those 
flights, one additional failure--a short circuit between FQIS wiring 
and power wiring--could cause a fuel tank explosion. Also, the 
probability of an explosion is between 1 in a million and 1 in 10 
million, per flight hour, which slightly exceeds the numerical unsafe 
condition guideline for individual flight risk discussed above.
    An issue that violates one or more of the individual flight risk 
guidelines would normally require corrective action that reduces the 
risk to a level that is below the unsafe condition guidelines. However, 
in this case the FAA acknowledged that the cost of corrective action is 
high, and that the available corrective action (fuel tank FRM systems) 
would reduce, but not eliminate, the number of expected flights with 
the condition we are concerned about (a latent failure plus flammable 
conditions inside the tank). The alternative actions for cargo 
airplanes would also reduce the number of expected flights with the 
condition we are concerned about, but to a lesser degree. The FAA has 
determined that allowing a moderate number of cargo flights per year 
(on average) with this condition provides an acceptable level of 
safety. As part of making this determination, we noted that the level 
of risk on the worst reasonably anticipated flights is similar to the 
level of risk for private and commercial pilots flying normal category 
airplanes.
    We have not changed the final rule regarding this issue.

Request To Require FQIS Modification in all Fuel Tanks

    National Air Traffic Controllers Association (NATCA) requested that 
we require changes to the FQIS to address the potential ``latent-plus-
one-failure scenario'' in all fuel tanks, not just in the center fuel 
tank.
    NATCA stated that the failure condition that is the subject of the 
SNPRM should be classified as a ``known'' latent-plus-one-failure 
condition when applying the FAA Transport Airplane Directorate Policy 
Memorandum 2003-112-15, ``SFAR 88--Mandatory Action Decision 
Criteria,'' dated February 25, 2015 (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgPolicy.nsf/0/
dc94c3a46396950386256d5e006aed11/$FILE/Feb2503.pdf). NATCA stated that 
this would have the effect of classifying the failure condition as an 
unsafe condition requiring corrective action in all affected fuel tanks 
regardless of flammability level.
    NATCA considered the combination of a latent in-tank failure with 
electrical energy transmitted into the fuel tank via the FQIS wiring 
due to an additional failure outside of the tank to be a ``known'' 
failure condition because that failure condition was considered to be 
the most likely cause of the TWA Flight 800 Model 747 accident. (That 
accident occurred on July 17, 1996, shortly after takeoff from John F. 
Kennedy International Airport in Jamaica, New York.) NATCA concluded 
that because the Model 757 FQIS is similar to that of the Model 747, 
both models are vulnerable to the same failure scenario. NATCA cited 
the unsafe condition statement for the SNPRM as evidence that the 
scenario should be classified as ``known.'' NATCA pointed out that the 
FAA issued AD 98-20-40, Amendment 39-10808 (63 FR 52147, September 30, 
1998), to address this issue for Model

[[Page 19478]]

747 airplanes, and pointed out that the FAA TARAM Handbook specifically 
states that Policy Memorandum 2003-112-15 should be followed in 
determining whether corrective action should be required for fuel tank 
safety concerns identified through SFAR 88.
    We disagree with the request to require modification of the FQIS in 
all fuel tanks. We have determined that, under the policy contained in 
the policy memorandum, this failure condition for the Model 757 FQIS 
should not be classified as ``known.'' The memo defines ``known'' 
failure conditions as follows:

    [T]hose conditions which have occurred in-service and are likely 
to occur on other products of the same or similar type design, and 
conditions which have been subject to mandatory corrective actions, 
following in-service findings, on products with a similar design of 
fuel system.

    We agree that the Model 757 FQIS has the same high-level system 
architecture and operating principles as those of the Model 747 FQIS, 
resulting in vulnerability to the same theoretical latent-plus-one-
failure scenario. There are, however, significant differences in the 
details of the Model 757 FQIS design that reduce the likelihood of the 
individual contributing failures. Those differences include the 
following:
     Improved FQIS probe terminal connector block design;
     The use of wiring that is not silver plated and therefore 
does not create silver sulfide deposits on the terminal blocks;
     The use of improved wire types and wiring installation 
practices outside of the fuel tanks; and
     The use of a system processor that provides significant 
isolation of the tank probe circuits from the indication and power 
circuits of the FQIS.
    We therefore did not consider that the FQIS designs for the Model 
747 and Model 757 were so similar that the Model 757 FQIS design should 
be considered to have a ``known'' latent-plus-one-failure condition 
vulnerability as defined in the policy memorandum. The provisions in 
the above definition for classifying a failure condition as ``known'' 
based on the existence of a similar design were intended to allow the 
FAA to evaluate the degree of similarity in the design, and to make 
discretionary judgments in determining that a failure condition that is 
believed to have occurred (and/or was addressed by AD action) in one 
specific design should be classified as ``known'' in a different 
specific design. The application of that discretion would be expected 
to involve evaluation of design detail differences and the effects of 
those differences on failure modes and failure probability. Based on 
our determination that sufficient design differences exist between the 
Model 757 and Model 747 FQIS designs to not classify the Model 757 FQIS 
latent-plus-one-failure condition as ``known,'' under the direction 
contained in the policy memorandum, this AD addresses that failure 
condition vulnerability only for the center fuel tank, which is the 
only high-flammability fuel tank on the Model 757.
    NATCA expressed a concern that the FAA did not understand NATCA's 
previous comment on this matter, and stated that the FAA had not 
considered the requirements of ``Element 2.a)'' from Policy Memorandum 
2003-112-15, dated February 25, 2015. In fact, we had addressed the 
requirements of ``Element 2.a)'' in the response to the comments under 
``Request to Revise Proposed AD Requirements to Apply to All Fuel 
Tanks'' of the SNPRM. The FAA understood the earlier comment and 
understands the more recent comment, but has reached a different 
conclusion about the classification of the failure condition under the 
guidance in the policy memorandum. We classified the Model 757 FQIS 
latent-plus-one-failure scenario as a theoretical vulnerability rather 
than a ``known'' combination of failures. Policy Memorandum 2003-112-
15, dated February 25, 2015, calls for corrective action for 
theoretical latent-plus-one-failure conditions only in high-
flammability fuel tanks. Contrary to the assertion in the NATCA 
comment, the acknowledgement of the scenario as theoretically possible 
and the consequent AD proposal to address the scenario in the high 
flammability center fuel tank do not automatically drive classification 
of the failure as ``known'' under the policy memorandum. We have not 
changed this final rule regarding this issue.

Request To Address Unsafe Condition in All Fuel Tanks, With or Without 
FRM

    NATCA requested that we require design changes to the FQIS to 
address the potential latent-plus-one-failure scenario in all fuel 
tanks of all Model 757 airplanes, regardless whether FRM is installed. 
NATCA stated that the minimum performance standards for FRM contained 
in 14 CFR part 25 allow flights to occur with flammable conditions in 
tanks that are required to incorporate FRM due to system performance as 
designed and due to system failures. In addition, time-limited dispatch 
with an inoperative FRM has been allowed in the master minimum 
equipment list (MMEL) for affected airplanes. Flights with flammable 
conditions and a pre-existing latent in-tank FQIS failure are 
reasonably anticipated to occur in the life of the affected fleet. For 
those flights, a fuel tank explosion could occur due to a single 
additional failure (hot short of power onto FQIS tank probe circuits). 
NATCA notes that four fuel tank explosion events have occurred in fuel 
tanks that are classified as low flammability.
    We disagree with the request. We have determined that the proposed 
corrective actions (either installation of FRM or specific FQIS changes 
limited to the center fuel tank) represent a reasonable, cost-effective 
method to achieve a meaningful reduction in the risk of an accident due 
to potential FQIS fuel tank ignition sources.
    The service history of conventional unheated aluminum wing tanks 
that contain Jet A fuel indicates that there would be little safety 
benefit by further limiting the flammability of these tanks. While 
NATCA expressed concern because fuel vapor ignition events have 
occurred in wing fuel tanks, NATCA did not differentiate service 
experience based on fuel type used (JP-4 versus Jet A fuel).
    Our review of the nine wing tank ignition events we know to have 
occurred on turbine-engine-powered transport airplanes shows that five 
of the nine airplanes were using JP-4 fuel, and this type of fuel is no 
longer used except on an emergency basis in the U.S. Use of JP-4 fuel 
in other parts of the world is also relatively rare, and is normally 
limited to areas with extremely cold airport conditions. Three of the 
remaining four events were caused by external heating of the wing by 
engine fires, and the remaining event occurred on the ground during 
maintenance. To date, there have been no fuel tank explosions in 
conventional unheated aluminum wing tanks fueled with Jet A fuel that 
have resulted in any fatalities.
    The flammability characteristics of JP-4 fuel results in the fuel 
tanks being flammable a significant portion of the time when an 
airplane is in flight. This is not the case for wing tanks containing 
Jet A fuel. Therefore, based on the low fleet average flammability of 
the Model 757 wing fuel tanks and on the specific features of the Model 
757 FQIS design, we have determined that the latent-plus-one 
vulnerability that exists in the Model 757 wing tank FQIS is not an 
unsafe condition requiring corrective action on in-service airplanes.
    We have not changed this final rule regarding this issue.

[[Page 19479]]

Request To Require Design Changes for Full Compliance with 
Airworthiness Regulations

    NATCA requested that we require design changes to the FQIS that 
would bring that system into full compliance with the applicable 
airworthiness regulations. NATCA stated that the failure condition that 
is the subject of the SNPRM represents a noncompliance of the type 
design with the requirements of 14 CFR 25.901(c) and 25.981(a)(3), even 
for low-flammability fuel tanks. NATCA stated that the proposed 
corrective actions would not bring the airplane design into compliance 
with those regulations ``as required by SFAR 88 and SFAR 88 Policy 
published by the FAA as Mandatory Corrective Action criteria in FAA 
Policy Statement No. 2003-112-15.'' NATCA added that the proposed 
alternative corrective actions for cargo airplanes do not comply with 
those regulations because the alternative actions do not fully 
eliminate the potential for the failure condition that is addressed by 
the SNPRM.
    We disagree with the request. SFAR 88, as modified by Amendment 21-
82, and Policy Memorandum 2003-112-15, dated February 25, 2003, do not 
specifically require noncompliant designs discovered through SFAR 88 to 
be brought into compliance. As originally issued, SFAR 88 required 
design approval holders to develop the corrective actions necessary to 
bring any noncompliant design fuel system features into compliance. 
However, SFAR 88 did not dictate that the FAA require a given 
corrective action. In fact, the FAA later published Amendment 21-82, 
``Equivalent Safety Provisions for Fuel Tank System Fault Tolerance 
Evaluations (SFAR 88),'' to clarify that the FAA would accept SFAR 88 
reports that do not provide corrective actions that directly comply 
with 14 CFR 25.981(a)(3) provided any aspects that do not comply are 
compensated for by factors that provide an equivalent level of safety. 
The FAA used the introduction of flammability reduction in place of 
corrective action for a specific ignition source as an example of a 
potentially acceptable compensating factor.
    Also, while the normal certification process requires proposed 
design changes to be compliant with the applicable regulations, 
applicants are permitted under 14 CFR part 11 to petition for an 
exemption from any FAA regulatory requirement. Policy Memorandum 2003-
112-15, dated February 25, 2003, did not state that the FAA would not 
consider a petition for exemption from an airworthiness requirement for 
a proposed design intended as corrective action for an SFAR 88 issue. 
We therefore consider that the applicant may petition for an exemption 
and propose a noncompliant design change, and the FAA may approve and 
issue an AD to require a noncompliant design change. Boeing's FRM 
design change for the Model 757 was approved some time ago. We have 
determined that for Model 757 airplanes, installation of FRM, instead 
of FQIS design changes, represents a reasonable, cost-effective method 
to achieve a meaningful overall reduction in the risk of an accident 
due to fuel tank ignition events. We therefore excluded airplanes with 
FRM installed from the applicability of this AD.

Request To Mandate Compliance with Airworthiness Regulations for Newly 
Produced Airplanes

    NATCA requested that we require newly produced airplanes to be in 
compliance with 14 CFR 25.901, 25.981(a), and 25.981(b). NATCA 
expressed concern that nearly 20 years after the TWA Flight 800 
accident, manufacturers have been allowed to continue production of 
airplanes without making changes to eliminate the FQIS latent-plus-one-
failure scenario, and that the FAA has granted exemptions to approve 
certain design changes without fully addressing the issue.
    We disagree with the request. This AD applies only to certain Model 
757 series airplanes, and the Model 757 is out of production. The 
comment is therefore outside of the scope of this AD. We have not 
changed the final rule regarding this issue.

Request To Allow Alternative Procedure for BITE Check

    FedEx proposed that we revise paragraph (h)(1) of the SNPRM to 
allow use of the FQIS BITE check procedure in its airplane maintenance 
manual (AMM) as an alternative to the procedure in Boeing Service 
Bulletin 757-28-0136, dated June 5, 2014, which does not apply to 
FedEx's fleet. We assume this is because FedEx operates some airplanes 
that were converted to a cargo configuration using a non-Boeing 
supplemental type certificate.
    We disagree with the request. FedEx's comment did not provide 
adequate information to show that its AMM procedure is equivalent to 
the procedure described in Boeing Service Bulletin 757-28-0136, dated 
June 5, 2014. FedEx's comment also did not identify the fault 
conditions for which dispatch would be prohibited. We therefore do not 
have sufficient information at this time to allow FedEx's proposed 
alternative procedure. However, under the provisions of paragraph (i) 
of this AD, we will consider requests for approval of alternative 
procedures, if sufficient data are submitted to substantiate that the 
change would provide an acceptable level of safety. We have not changed 
this final rule regarding this request.

Request To Reduce Compliance Time

    NATCA requested that we reduce the compliance time to 5 years or 
less. NATCA noted that the proposed 72-month compliance time would 
result in a corrective action deadline that is approximately 27 years 
after the TWA Flight 800 accident. NATCA stated that such a long delay 
in action is not in the public interest.
    We disagree with the request to reduce the compliance time, which 
we have determined is necessary to give operators adequate time to 
prepare for and perform the required modifications without excessive 
disruption of operations. We had initially proposed 60 months, but 
extended that to 72 months in response to operator comments, which 
included extension requests of up to 108 months. NATCA made a similar 
comment to the NPRM (77 FR 12506, March 1, 2012), requesting a 
reduction in the compliance time to 36 months, and the FAA provided its 
response in the SNPRM under ``Request to Reduce Compliance Time.'' We 
have not changed this final rule regarding this issue.

Statement Regarding Compliance Time for Wire Separation

    FedEx stated that without service information for the wire 
separation, it cannot effectively determine whether the proposed 72-
month compliance time is acceptable.
    We had previously determined, as specified in the SNPRM, that the 
work involved for the cargo airplane wire separation modification would 
take 230 work-hours, and a compliance time of 72 months would be 
adequate for operators to perform the modification on their affected 
fleets. Boeing has since provided an updated estimate of 74 work-hours 
for the alternative modification for cargo airplanes. We have revised 
the cost estimate accordingly in this final rule, but since this change 
reduces the work-hour estimate, it is not necessary to adjust the 
compliance time to accommodate the workload for this action for cargo 
operators.

[[Page 19480]]

Request To Remove Reference to ``Fuel Tank Systems''

    Paragraph (g) of the SNPRM would have required modification of 
``the FQIS wiring or fuel tank systems.'' Boeing asked that we remove 
reference to ``fuel tank systems'' in this proposed requirement because 
a fuel tank system modification could be done as an AMOC.
    We agree with the commenter's request and rationale. We have 
removed the references to ``fuel tank systems'' throughout the preamble 
and in paragraph (g) of this AD.

Request To Clarify Condition Requiring Repair

    Boeing requested that we revise paragraph (h)(1) of the SNPRM to 
specify that repair is required for any ``nondispatchable'' fault code 
recorded before or as a result of the BITE check. (The SNPRM would have 
required repair for any fault code.) Boeing requested this change to 
make the repair requirement consistent with the BITE check service 
information referenced in the SNPRM (Boeing Service Bulletin 757-28-
0136, dated June 5, 2014).
    We agree with the request. The intent of the SNPRM was to require 
correction only of faults identified as ``nondispatchable.'' The SNPRM 
used the terminology ``as applicable'' to indicate this intent, but we 
agree that further clarification is appropriate. We have revised 
paragraph (h)(1) in this AD as requested by the commenter.

Request To Clarify End Point for FQIS Wire Separation

    Paragraph (h)(2) of the SNPRM specified that the FQIS wiring 
separation was to be done on the wiring that runs between the FQIS 
processor and the center fuel tank. Boeing requested that we change 
``the center fuel tank'' to ``the center fuel tank wall penetrations.'' 
Boeing requested this change to clarify the end point for the FQIS wire 
separation.
    We agree with the request. Boeing's suggestion is consistent with 
the intent of this AD, and improves the clarity of the requirement. We 
have revised paragraph (h)(2) in this AD to incorporate Boeing's 
request.

Request To Delay Final Rule Pending New Service Information

    Boeing requested that we delay issuance of the final rule pending 
issuance of new service information that would specifically define an 
acceptable wiring configuration that complies with the proposed 
requirements.
    We disagree with the request because the referenced service 
information was not available at the time we were ready to publish the 
final rule, and we cannot reliably predict the time that service 
information will be issued by Boeing. We do not consider it in the 
public interest to further delay this rulemaking. We have determined 
that it is necessary to proceed with issuing the final rule as 
proposed. Operators may, however, request approval under the provisions 
of paragraph (i) of this AD to use a future approved service bulletin, 
if developed, as an AMOC with the requirements of this AD, or we may 
approve the service bulletin as a global AMOC.

Statement Regarding Unsafe Condition

    Boeing stated that it has accepted the FAA's requirement to provide 
service information defining an acceptable wire separation 
modification, but, based on previously provided analysis, maintained 
that the risk level is less than extremely improbable. As asserted in 
earlier comments, Boeing considers the design of the affected airplanes 
safe and the proposed requirements therefore unnecessary.
    We disagree with Boeing's assertions for the reasons discussed 
extensively in our response to Boeing's similar comment in the SNPRM. 
The FAA's response to Boeing's assertion is covered in the response to 
comments in the SNPRM under ``Request to Withdraw NPRM (77 FR 12506, 
March 1, 2012): Unjustified by Risk.''

Additional Change Made to This AD

    We have revised the introductory text to paragraph (h) of this AD 
to clarify that the alternative modification for cargo airplanes must 
be accompanied by periodic BITE checks started within 6 months after 
the effective date of this AD. And, for airplanes converted to an all-
cargo configuration more than 6 months after the effective date of this 
AD, operators must perform the first BITE check before flight after the 
conversion. In reviewing the proposed requirements after publication of 
the SNPRM, we recognized that operators might interpret the 
requirements as allowing a delay in the decision to exercise the cargo 
airplane alternative until late in the compliance period. That is not 
the literal meaning of the proposed language of the requirement, and 
was not the FAA's intent. However, we determined that we should clarify 
the language of paragraph (h) of this AD regarding the required timing 
for the first BITE check if an operator chooses to exercise the cargo 
airplane alternative.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
SNPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the SNPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We have reviewed Boeing Service Bulletin 757-28-0136, dated June 5, 
2014, which describes procedures for a BITE check (check of built-in 
test equipment). This service information is reasonably available 
because the interested parties have access to it through their normal 
course of business or by the means identified in the ADDRESSES section.

Costs of Compliance

    We estimate that this 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 AD:

                              Estimated Costs: Basic Requirement for All Airplanes
----------------------------------------------------------------------------------------------------------------
                Action                          Labor cost             Parts cost          Cost per product
----------------------------------------------------------------------------------------------------------------
Fully correct FQIS vulnerability to     1,200 work-hours x $85              $200,000  $302,000
 latent-plus-one-failure conditions.     per hour = $102,000.
----------------------------------------------------------------------------------------------------------------

[[Page 19481]]

 
                             Estimated Costs: Alternative Actions for All Airplanes
----------------------------------------------------------------------------------------------------------------
Install FRM...........................  720 work-hours x $85 per             323,000  $384,200.
                                         hour = $61,200.
----------------------------------------------------------------------------------------------------------------
                            Estimated Costs: Alternative Actions for Cargo Airplanes
----------------------------------------------------------------------------------------------------------------
Wire separation.......................  74 work-hours x $85 per               10,000  $16,290.
                                         hour = $6,290.
----------------------------------------------------------------------------------------------------------------
FQIS BITE check (required with wire     1 work-hour x $85 per                      0  $85 per check (4 checks
 separation alternative actions).        hour = $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 AD 
will be done on only the 19 affected non-air-carrier passenger 
airplanes, for an estimated passenger fleet cost of $7,299,800. 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 $2,410,920 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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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):


2016-07-07 The Boeing Company: Amendment 39-18452; Docket No. FAA-
2012-0187; Directorate Identifier 2011-NM-094-AD.

(a) Effective Date

    This AD is effective May 10, 2016.

(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 
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 ignition sources 
inside the center fuel tank, which, in combination with flammable 
fuel vapors, could result in a fuel tank explosion and consequent 
loss of the airplane.

(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 
fuel quantity indication system (FQIS) wiring 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) Alternative Actions for Cargo Airplanes

    For airplanes used exclusively for cargo operations: As an 
alternative to the requirements of paragraph (g) of this AD, do the 
actions 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. To exercise this alternative, operators 
must perform the first inspection required under paragraph (h)(1) of 
this AD within 6 months after the effective date of this AD. To 
exercise this alternative for airplanes returned to service after 
conversion of the airplane from a passenger configuration to an all-
cargo configuration more than 6 months after the effective date of 
this AD, operators must perform the first inspection required under 
paragraph (h)(1) of this AD prior to further flight after the 
conversion.
    (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

[[Page 19482]]

Accomplishment Instructions of Boeing Service Bulletin 757-28-0136, 
dated June 5, 2014. If any nondispatchable fault code is 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 nondispatchable fault 
found, in accordance with the Accomplishment Instructions of 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 wall penetrations, including any 
circuits that 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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO, to make those findings. To be approved, the 
repair method, modification deviation, or alteration deviation must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.

(j) Related Information

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

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Service Bulletin 757-28-0136, dated June 5, 2014.
    (ii) Reserved.
    (3) 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.
    (4) You may view this service information at 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on March 21, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-07150 Filed 4-4-16; 8:45 am]
 BILLING CODE 4910-13-P



                                           19472                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations

                                             (1) Is not a ‘‘significant regulatory                 pressure switch in-line fuses, and do                    (3) For Boeing service information
                                           action’’ under Executive Order 12866,                   applicable wiring changes, on the left, right,        identified in this AD, contact Boeing
                                             (2) Is not a ‘‘significant rule’’ under               and center wing forward spars, forward                Commercial Airplanes, Attention: Data &
                                           DOT Regulatory Policies and Procedures                  auxiliary fuel tank, and aft auxiliary fuel           Services Management, 3855 Lakewood
                                                                                                   tank. Do the actions in accordance with the           Boulevard, MC D800–0019, Long Beach, CA
                                           (44 FR 11034, February 26, 1979),                       Accomplishment Instructions of Boeing                 90846–0001; telephone 206–544–5000,
                                             (3) Will not affect intrastate aviation               Service Bulletin MD80–28–226, Revision 1,             extension 2; fax 206–766–5683; Internet
                                           in Alaska, and                                          dated March 6, 2015.                                  https://www.myboeingfleet.com.
                                             (4) Will not have a significant                                                                                (4) You may view this service information
                                           economic impact, positive or negative,                  (h) Credit for Previous Actions
                                                                                                                                                         at FAA, Transport Airplane Directorate, 1601
                                           on a substantial number of small entities                  This paragraph provides credit for the             Lind Avenue SW., Renton, Washington. For
                                           under the criteria of the Regulatory                    actions required by paragraph (g) of this AD,         information on the availability of this
                                           Flexibility Act.                                        if those actions were performed before the            material at the FAA, call 425–227–1221.
                                                                                                   effective date of this AD using Boeing Service           (5) You may view this service information
                                           List of Subjects in 14 CFR Part 39                      Bulletin MD80–28–226, dated April 14, 2010,           that is incorporated by reference at the
                                                                                                   which is incorporated by reference in AD              National Archives and Records
                                             Air transportation, Aircraft, Aviation                2011–01–16, Amendment 39–16573 (76 FR
                                           safety, Incorporation by reference,                                                                           Administration (NARA). For information on
                                                                                                   1993, January 12, 2011).                              the availability of this material at NARA, call
                                           Safety.                                                                                                       202–741–6030, or go to: http://
                                                                                                   (i) Alternative Methods of Compliance
                                           Adoption of the Amendment                               (AMOCs)                                               www.archives.gov/federal-register/cfr/ibr-
                                                                                                                                                         locations.html.
                                             Accordingly, under the authority                         (1) The Manager, Los Angeles Aircraft
                                           delegated to me by the Administrator,                   Certification Office (ACO), FAA, has the                Issued in Renton, Washington, on March
                                                                                                   authority to approve AMOCs for this AD, if            22, 2016.
                                           the FAA amends 14 CFR part 39 as
                                                                                                   requested using the procedures found in 14            Michael Kaszycki,
                                           follows:
                                                                                                   CFR 39.19. In accordance with 14 CFR 39.19,           Acting Manager, Transport Airplane
                                                                                                   send your request to your principal inspector         Directorate, Aircraft Certification Service.
                                           PART 39—AIRWORTHINESS
                                                                                                   or local Flight Standards District Office, as
                                           DIRECTIVES                                              appropriate. If sending information directly          [FR Doc. 2016–07230 Filed 4–4–16; 8:45 am]
                                                                                                   to the manager of the Los Angeles ACO, send           BILLING CODE 4910–13–P
                                           ■ 1. The authority citation for part 39                 it to the attention of the person identified in
                                           continues to read as follows:                           paragraph (j)(1) of this AD. Information may
                                               Authority: 49 U.S.C. 106(g), 40113, 44701.          be emailed to: 9-ANM-LAACO-AMOC-                      DEPARTMENT OF TRANSPORTATION
                                                                                                   Requests@faa.gov.
                                           § 39.13   [Amended]                                        (2) Before using any approved AMOC,                Federal Aviation Administration
                                                                                                   notify your appropriate principal inspector,
                                           ■ 2. The FAA amends § 39.13 by adding
                                                                                                   or lacking a principal inspector, the manager         14 CFR Part 39
                                           the following new airworthiness                         of the local flight standards district office/
                                           directive (AD):                                         certificate holding district office.                  [Docket No. FAA–2012–0187; Directorate
                                           2016–07–08 The Boeing Company:                             (3) An AMOC that provides an acceptable            Identifier 2011–NM–094–AD; Amendment
                                               Amendment 39–18453; Docket No.                      level of safety may be used for any repair,           39–18452; AD 2016–07–07]
                                               FAA–2016–5036; Directorate Identifier               modification, or alteration required by this
                                               2015–NM–180–AD.                                     AD if it is approved by the Boeing                    RIN 2120–AA64
                                                                                                   Commercial Airplanes Organization
                                           (a) Effective Date                                      Designation Authorization (ODA) that has              Airworthiness Directives; The Boeing
                                             This AD is effective April 20, 2016.                  been authorized by the Manager, Los Angeles
                                                                                                   ACO, to make those findings. To be                    Company Airplanes
                                           (b) Affected ADs                                        approved, the repair method, modification             AGENCY:  Federal Aviation
                                             None.                                                 deviation, or alteration deviation must meet
                                                                                                                                                         Administration (FAA), DOT.
                                                                                                   the certification basis of the airplane, and the
                                           (c) Applicability                                       approval must specifically refer to this AD.          ACTION: Final rule.
                                              This AD applies to The Boeing Company
                                           Model DC–9–83 (MD–83) airplane, fuselage                (j) Related Information                               SUMMARY:   We are adopting a new
                                           number 2155 (variable number 80E718, serial                (1) For more information about this AD,            airworthiness directive (AD) for certain
                                           number 53192), certificated in any category.            contact Samuel Lee, Aerospace Engineer,               The Boeing Company Model 757
                                                                                                   Propulsion Branch, ANM–140L, FAA, Los                 airplanes. This AD was prompted by
                                           (d) Subject                                             Angeles ACO, 3960 Paramount Boulevard,                fuel system reviews conducted by the
                                             Air Transport Association (ATA) of                    Lakewood, CA 90712–4137; phone: 562–627–
                                                                                                   5262; fax: 562–627–5210; email: samuel.lee@
                                                                                                                                                         manufacturer. This AD requires
                                           America Code 28: Fuel.
                                                                                                   faa.gov.                                              modifying the fuel quantity indication
                                           (e) Unsafe Condition                                       (2) Service information identified in this         system (FQIS) wiring to prevent
                                              This AD was prompted by fuel system                  AD that is not incorporated by reference is           development of an ignition source
                                           reviews conducted by the manufacturer. We               available at the addresses specified in               inside the center fuel tank. We are
                                           are issuing this AD to prevent the potential            paragraphs (k)(3) and (k)(4) of this AD.              issuing this AD to prevent ignition
                                           of ignition sources inside fuel tanks, which,                                                                 sources inside the center fuel tank,
                                                                                                   (k) Material Incorporated by Reference
                                           in combination with flammable fuel vapors,                                                                    which, in combination with flammable
                                           could result in fuel tank explosions and                   (1) The Director of the Federal Register
                                                                                                   approved the incorporation by reference               fuel vapors, could result in a fuel tank
                                           consequent loss of the airplane.
                                                                                                   (IBR) of the service information listed in this       explosion and consequent loss of the
                                           (f) Compliance                                          paragraph under 5 U.S.C. 552(a) and 1 CFR             airplane.
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                                              Comply with this AD within the                       part 51.                                              DATES:  This AD is effective May 10,
                                           compliance times specified, unless already                 (2) You must use this service information
                                                                                                   as applicable to do the actions required by
                                                                                                                                                         2016.
                                           done.
                                                                                                   this AD, unless the AD specifies otherwise.             The Director of the Federal Register
                                           (g) Fuse Installation                                      (i) Boeing Service Bulletin MD80–28–226,           approved the incorporation by reference
                                              Within 60 months after the effective date            Revision 1, dated March 6, 2015.                      of a certain publication listed in this AD
                                           of this AD, install fuel level float and                   (ii) Reserved.                                     as of May 10, 2016.


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                                                                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations                                        19473

                                           ADDRESSES:   For service information                    revise the applicability, including                   Guidance_Library/rgPolicy.nsf/0/
                                           identified in this final rule, contact                  alternative actions for cargo airplanes,              DC94C3A46396950386256
                                           Boeing Commercial Airplanes,                            and extend the compliance time. We are                D5E006AED11?OpenDocument&High
                                           Attention: Data & Services Management,                  issuing this AD to prevent ignition                   light=anm-100-2003-112-15), dated
                                           P. O. Box 3707, MC 2H–65, Seattle, WA                   sources inside the center fuel tank,                  February 25, 2003, and the FAA’s
                                           98124–2207; telephone 206–544–5000,                     which, in combination with flammable                  Transport Airplane Risk Assessment
                                           extension 1; fax 206–766–5680; Internet                 fuel vapors, could result in fuel tank                Methodology (TARAM) (Policy
                                           https://www.myboeingfleet.com. You                      explosions and consequent loss of the                 Statement PS–ANM–25–05) (http://
                                           may view this referenced service                        airplane.                                             rgl.faa.gov/Regulatory_and_Guidance_
                                           information at the FAA, Transport                       Record of Ex Parte Communication                      Library/rgPolicy.nsf/0/4E5AE8707164
                                           Airplane Directorate, 1601 Lind Avenue                                                                        674A862579510061F96B?Open
                                           SW., Renton, WA. For information on                        In preparation of AD actions such as
                                                                                                   NPRMs and immediately adopted rules,                  Document&Highlight=ps-anm-25-05).
                                           the availability of this material at the
                                                                                                   it is the practice of the FAA to obtain               The FAA determined that installing
                                           FAA, call 425–227–1221. It is also
                                                                                                   technical information and information                 FRM that meets 14 CFR part 125 would
                                           available on the Internet at http://
                                           www.regulations.gov by searching for                    on the operational and economic impact                be one acceptable way to address the
                                           and locating Docket No. FAA–2012–                       from design approval holders and                      identified unsafe condition, so airplanes
                                           0187.                                                   aircraft operators. We discussed certain              on which such a modification was
                                                                                                   issues related to this final rule in a                incorporated were excluded from the
                                           Examining the AD Docket                                 meeting held December 1, 2015, with                   applicability of the SNPRM. Other
                                             You may examine the AD docket on                      Airlines for America (A4A) and other                  modifications identified later in this
                                           the Internet at http://                                 members of the aviation industry. This                discussion are available as alternative
                                           www.regulations.gov by searching for                    final rule addresses the issues discussed             actions to installing FRM for certain
                                           and locating Docket No. FAA–2012–                       during that meeting that are relevant to              operations. We have determined it is
                                           0187; or in person at the Docket                        this final rule. A summary of this                    necessary to proceed with issuance of
                                           Management Facility between 9 a.m.                      meeting can be found in the rulemaking                this final rule.
                                           and 5 p.m., Monday through Friday,                      docket at http://www.regulations.gov by
                                           except Federal holidays. The AD docket                  searching for and locating Docket No.                 Request To Withdraw SNPRM:
                                           contains this AD, the regulatory                        FAA–2012–0187.                                        Intrusive, Expensive, Unnecessary
                                           evaluation, any comments received, and                  Comments                                                 A4A stated that Airbus and Boeing
                                           other information. The address for the                                                                        have indicated to them that the service
                                           Docket Office (phone: 800–647–5527) is                    We gave the public the opportunity to
                                                                                                   participate in developing this AD. The                bulletins for the wire separation
                                           Docket Management Facility, U.S.
                                                                                                   following presents the comments                       modification that is part of the cargo
                                           Department of Transportation, Docket
                                           Operations, M–30, West Building                         received on the SNPRM and the FAA’s                   airplane alternative actions will be
                                           Ground Floor, Room W12–140, 1200                        response to each comment.                             intrusive and expensive and will not
                                           New Jersey Avenue SE., Washington,                                                                            significantly improve safety. A4A stated
                                                                                                   Request To Withdraw SNPRM: New
                                           DC 20590.                                                                                                     that the safety analyses performed by
                                                                                                   Certification Requirements for
                                                                                                   Flammability Reduction Means (FRM)                    the aircraft manufacturers do not
                                           FOR FURTHER INFORMATION CONTACT: Jon
                                           Regimbal, Aerospace Engineer,                           Unwarranted                                           classify the proposed modifications as
                                           Propulsion Branch, ANM–140S, FAA,                                                                             safety critical. A4A noted that those
                                                                                                      A4A, representing U.S. cargo                       service bulletins will not be issued as
                                           Seattle Aircraft Certification Office                   operators, stated that the FAA intends to
                                           (ACO), 1601 Lind Avenue SW., Renton,                                                                          ‘‘Alert’’ service bulletins. Additionally,
                                                                                                   issue rulemaking requiring U.S. cargo
                                           WA 98057–3356; phone: 425–917–6506;                                                                           A4A stated that foreign regulatory
                                                                                                   operators to do additional fuel safety
                                           fax: 425–917–6590; email:                                                                                     authorities, aircraft manufacturers, and
                                                                                                   modifications to meet the latest aircraft
                                           jon.regimbal@faa.gov.                                                                                         airlines do not support that a safety
                                                                                                   certification requirements.
                                           SUPPLEMENTARY INFORMATION:                                 We infer that A4A considers that                   issue remains.
                                                                                                   requiring airplanes to meet the latest                   We infer that A4A is requesting that
                                           Discussion
                                                                                                   certification requirements is not                     we withdraw the SNPRM because the
                                             We issued a supplemental notice of                    warranted and that the SNPRM should                   airplane manufacturers have determined
                                           proposed rulemaking (SNPRM) to                          therefore be withdrawn. We assume that                that an unsafe condition does not exist
                                           amend 14 CFR part 39 by adding an AD                    by ‘‘the latest aircraft certification                and the SNPRM will not significantly
                                           that would apply to certain The Boeing                  requirements,’’ A4A is referring to the               improve safety. We do not agree that the
                                           Company Model 757 airplanes. The                        relatively new requirements for FRM                   SNPRM should be withdrawn. We
                                           SNPRM published in the Federal                          contained in 14 CFR part 125.                         acknowledge that Boeing does not
                                           Register on February 23, 2015 (80 FR                       We do not agree that the SNPRM                     consider the condition associated with
                                           9400) (‘‘the SNPRM’’). We preceded the                  should be withdrawn. This AD is not                   FQIS on these airplanes to be unsafe.
                                           SNPRM with a notice of proposed                         specifically intended to require that the
                                                                                                                                                         We disagree with Boeing’s assertions,
                                           rulemaking (NPRM) that published in                     affected airplanes meet the flammability
                                                                                                                                                         for the reasons discussed extensively in
                                           the Federal Register on March 1, 2012                   requirements of 14 CFR part 125. It is
                                                                                                                                                         our response to Boeing’s similar
                                           (77 FR 12506). The NPRM proposed to                     instead intended to address an unsafe
                                           require modifying the fuel quantity                     condition as required by 14 CFR part 39               comment in the SNPRM, under
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                                           indication system (FQIS) wiring or fuel                 identified by the FAA under the policy                ‘‘Request to Withdraw NPRM (77 FR
                                           tank systems to prevent development of                  contained in the FAA’s Special Federal                12506, March 1, 2012): Unjustified by
                                           an ignition source inside the center fuel               Aviation Regulation No. 88 (14 CFR part               Risk.’’ We have determined that it is
                                           tank. The NPRM was prompted by fuel                     21, SFAR 88) AD decision policy (Policy               necessary to proceed with issuance of
                                           system reviews conducted by the                         Memorandum ANM–100–2003–112–15)                       this final rule.
                                           manufacturer. The SNPRM proposed to                     (http://rgl.faa.gov/Regulatory_and_


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                                           19474                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations

                                           Request To Withdraw SNPRM: Global                       U.S. cargo operators, resulting in the                that cargo operators already have
                                           Economic Disadvantage to U.S.                           loss of U.S. jobs.                                    recurring expenses for Enhanced
                                           Operators                                                 We do not agree to withdraw the                     Airworthiness Program for Airplane
                                                                                                   SNPRM for corrective action on cargo                  Safety (EAPAS) maintenance program
                                              A4A does not expect that foreign                     airplanes. As part of the AD                          tasks that continue to help ensure fuel
                                           regulators will require modification of                 development process, the FAA works                    tank safety. A4A added that cargo
                                           affected foreign-registered aircraft, and               with the affected manufacturer to                     operators have already invested in
                                           stated that the competitive position of                 develop a cost estimate for the                       improved and more expensive fuel tank
                                           U.S. cargo operators will be harmed as                  corrective actions in a proposed AD.                  component repair and overhaul
                                           a result. A4A stated that foreign                       The FAA considers all possible                        processes.
                                           regulatory agencies did not mandate                     corrective actions proposed by a                         We infer that A4A is requesting that
                                           retrofit of FRM for cargo airplanes, and                manufacturer in an attempt to minimize                we withdraw the SNPRM because the
                                           therefore A4A did not expect that those                 the cost burden on operators. In some                 costs of addressing previously identified
                                           authorities will mandate FQIS changes                   cases the FAA even makes a specific                   fuel tank unsafe conditions has been
                                           for their operators. A4A’s comment                      suggestion to a manufacturer for a less               high, and that the additional cost to
                                           made reference to documents published                   costly alternative. In the end, the                   address the FQIS latent-plus-one issue
                                           by the European Aviation Safety Agency                  manufacturer is responsible for                       will also be high, with very little safety
                                           (EASA), the Civil Aviation Authority of                 development of an appropriate                         benefit.
                                           China (CAAC), and the Japan Civil                       corrective action.                                       We do not agree to withdraw the
                                           Aviation Bureau (JCAB) as evidence that                   While the FAA attempts to minimize                  SNPRM. We acknowledge that the total
                                           those agencies are not planning action                  the costs associated with a required                  industry cost to address other fuel tank
                                           to address any unsafe condition                         corrective action for a U.S. product,                 system unsafe conditions has been high.
                                           associated with FQIS.                                   ultimately the FAA has the                            The SFAR 88 studies for Boeing
                                              We infer that A4A is requesting that                 responsibility as the civil aviation                  airplanes identified several basic design
                                           we withdraw the NPRM because other                      authority (CAA) of the state of design to             deficiencies in lightning protection that
                                           foreign regulatory agencies have                        address unsafe conditions through AD                  could cause an ignition source in a fuel
                                           determined that an unsafe condition                     action. Other CAAs overseeing foreign                 tank in the event of a lightning strike,
                                           does not exist with regard to FQIS as                   operators will typically apply the FAA                and several issues with fuel pump
                                           addressed by the proposed AD.                           AD or develop a similar AD for U.S.                   systems and fuel valve systems where a
                                              We were unable to examine the EASA                   products operated under each CAA’s                    single failure could result in an ignition
                                           document A4A attempted to reference                     jurisdiction. Other CAAs rely heavily on              source in a fuel tank. Fuel pump issues
                                           because the reference number was                        the knowledge and judgment of the                     are suspected to have caused several
                                           incomplete. We do not agree that the                    CAA of the state of design to identify                fuel tank ignition events, so these issues
                                           CAAC and JCAB documents indicate a                      unsafe conditions and appropriate                     were considered to be the highest
                                           position on the unsafe condition                        corrective actions for products of that               priority for the development of
                                           addressed by the SNPRM. Both of those                   state. The FAA is not aware at this time              corrective actions and related AD
                                           documents simply state a requirement                    of any affected CAAs that do not plan                 actions. The FAA considers the cost of
                                           for existing type certificate holders to                to issue a corresponding mandate to                   addressing those issues to be clearly
                                           review fuel tank designs that is similar                address the unsafe condition associated               justified. Deficiencies in maintenance
                                           to the FAA’s SFAR 88. Those                             with FQIS identified in the proposed                  programs and inappropriate component
                                           documents do not state positions on any                 AD. Even if such a situation occurs, the              repair actions that could lead to
                                           unsafe conditions or AD proposals                       FAA would not use a foreign CAA’s                     inadvertent significant increases in the
                                           identified by the FAA, the CAAC, or the                 position as a justification for not                   risk of an ignition source in a fuel tank
                                                                                                   addressing an unsafe condition                        were also identified, and the cost of
                                           JCAB.
                                                                                                   identified by the FAA. While we                       airworthiness limitations to address
                                              A4A stated that the U.S. air cargo                   acknowledge such a situation could                    those issues is also considered to be
                                           industry is currently in an extremely                   harm the competitive position of a U.S.               justified.
                                           competitive global market. Additional                   operator, we are still obligated by U.S.                 The SFAR 88 studies and the FAA’s
                                           lower deck capacity on passenger                        law and by international treaties to                  subsequent decision-making process
                                           aircraft, especially through Middle East                address the identified unsafe condition.              identified FQIS vulnerability of Model
                                           hubs, has significantly increased the                   We have determined that it is necessary               707, 727, 737, 747, 757, 767, and 777
                                           need for cargo industry capacity.                       to proceed with issuance of this final                airplanes as an unsafe condition
                                           Several cargo carriers have ceased                      rule.                                                 requiring corrective action. While the
                                           operations, and many others have                                                                              more recently designed of these airplane
                                           parked some aircraft. U.S. carriers                     Request To Withdraw SNPRM: Costs of                   models have significant improvements
                                           compete directly with foreign cargo                     Compliance                                            in FQIS design details, they all have
                                           operators. A4A stated that any                             A4A stated that the proposed                       similar FQIS design architecture with
                                           additional costs on U.S. cargo operators                modifications are very costly, and noted              respect to the identified failure scenario.
                                           that are not incurred by foreign                        that United Parcel Service (UPS) has                  That architecture is vulnerable to a
                                           operators will make U.S. operators less                 estimated a total cost of $16 million for             combination of a latent in-tank wiring
                                           competitive and will lead to the loss of                its fleet of four aircraft types that are             failure and a subsequent wiring failure
                                           jobs in the U.S.                                        potentially affected by the SNPRM and                 outside of the tank that connects a high
                                              We infer that A4A is requesting that                 other similar planned ADs. A4A pointed                power source to the FQIS tank circuit
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                                           we withdraw the proposal to require                     out that U.S. cargo operators have                    creating an ignition source in a fuel
                                           corrective action on cargo airplanes                    already spent tens of millions of dollars             tank. This failure combination was
                                           because non-U.S. cargo operators will                   on fuel tank safety improvements. UPS                 determined by the National
                                           not be required to make similar                         alone has spent $35.5 million to comply               Transportation Safety Board (NTSB) to
                                           modifications, and the FAA AD action                    with 51 SFAR 88 ADs on the four fleet                 have been the most likely cause of the
                                           would harm the competitive position of                  types potentially affected. A4A noted                 Model 747 fuel tank explosion accident


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                                                                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations                                        19475

                                           off Long Island in 1996. NTSB Safety                    risk below the FAA’s TARAM                            assuming the average interval between
                                           Recommendation A–98–038 (http://                        individual flight risk guideline level for            events is significantly improved to the
                                           www.ntsb.gov/about/employment/_                         urgent action. As discussed below in                  extent that the overall fleet risk is
                                           layouts/ntsb.recsearch/                                 our response to ‘‘Request to Remove                   considered acceptable, we would still
                                           Recommendation.aspx?Rec=A-98-038)                       Alternative Actions for Cargo                         address unsafe conditions identified
                                           recommended that the FAA require that                   Airplanes,’’ we determined that further               based on the published FAA policy for
                                           FQIS wiring on all airplane models that                 changes to further reduce the risk below              SFAR 88 corrective actions and the
                                           have similar wiring installations be                    the TARAM individual flight risk                      current FAA guidelines for
                                           separated and shielded to the maximum                   corrective action guideline of 1 in 10                identification of unsafe conditions on
                                           extent possible.                                        million per flight hour would                         transport airplanes when the individual
                                              The FAA issued AD 98–20–40,                          significantly increase the costs of                   flight safety risk exceeds our guidelines,
                                           Amendment 39–10808 (63 FR 52147,                        compliance and are not necessary to                   as in this case. We have determined that
                                           September 30, 1998); and AD 99–03–04,                   adequately address the unsafe                         it is necessary to proceed with issuance
                                           Amendment 39–11018 (64 FR 4959,                         condition. We have determined that it is              of this final rule.
                                           February 2, 1999); to address this issue                necessary to proceed with issuance of
                                           on early Model 747 and Model 737                        this final rule.                                      Request To Withdraw SNPRM: All
                                           airplanes, respectively, which used the                                                                       Related NTSB Safety Recommendations
                                           same FQIS as the accident airplane. The                 Request To Withdraw SNPRM: Unsafe                     Closed
                                           FAA subsequently (in 2003) determined                   Condition Addressed by Previous
                                                                                                                                                            A4A stated that the NTSB previously
                                           that this same architectural                            Requirements
                                                                                                                                                         issued the following safety
                                           vulnerability was an unsafe condition                     A4A stated that there have been no                  recommendations related to
                                           for high flammability fuel tanks on all                 fuel tank ignition incidents since the                flammability, wiring, and wiring
                                           Boeing jet transports existing at that                  previously issued fuel tank safety ADs                maintenance:
                                           time. This determination was consistent                 were implemented. A4A stated that this                   • A–96–174—Preclude flammable
                                           with the published FAA policy for                       provides direct evidence that FAA                     fuel air mixtures in fuel tanks. Closed—
                                           SFAR 88 corrective actions and with the                 projections for additional incidents                  Acceptable Action: FRM Rulemaking.
                                           current FAA TARAM guidelines for                        were overstated and that SFAR 88                      Safety Recommendation A–96–174 can
                                           identification of unsafe conditions on                  changes have worked. They further                     be found at http://www.ntsb.gov/_
                                           transport airplanes.                                    stated that no unsafe condition exists,               layouts/ntsb.recsearch/
                                              The FAA deferred acting on this                      asserting that service experience has                 Recommendation.aspx?Rec=A-96-174.
                                           unsafe condition until after the FRM                    shown that the fuel tank safety issues                   • A–98–038—Separation of FQIS
                                           rulemaking activity was complete                        have been sufficiently addressed with                 wires to the max extent possible.
                                           because introduction of FRM had the                     significant previous modifications,                   Closed—Acceptable Action: SFAR 88
                                           potential to change the classification of               recurring maintenance, controlled                     Rulemaking.
                                           many of the affected fuel tanks to low                  overhaul processes and repair processes,                 • A–98–039—Require surge
                                           flammability. When the final decision                   and maintenance program tasks.                        protection systems for FQIS wires.
                                           for the FRM rule did not include a                        We infer that A4A is requesting that                Closed—Acceptable Action: SFAR 88
                                           requirement for FRM on all airplanes,                   we withdraw the SNPRM because                         Rulemaking. Safety Recommendation
                                           the FAA resumed the planned actions to                  previously required actions have                      A–98–039 can be found at http://
                                           address the identified FQIS unsafe                      adequately addressed the need for                     www.ntsb.gov/about/employment/_
                                           condition on the airplanes that were not                improvements in fuel tank safety.                     layouts/ntsb.recsearch/
                                           required to have FRM.                                     We do not agree to withdraw the                     Recommendation.aspx?Rec=A-98-039.
                                              The FAA considers the safety benefit                 SNPRM. Until recently, fuel tank                         • A–00–106—Assess wiring
                                           of the SNPRM to be significant for both                 ignition incidents on U.S.- and                       criticality and separation. Closed—
                                           passenger and cargo airplanes. We                       European-manufactured transport                       Acceptable Action: EAPAS/FTS
                                           estimate that the installation of                       airplanes have occurred roughly once                  Rulemaking. Safety Recommendation
                                           compliant FRM will provide                              every five to six years, with the most                A–00–106 can be found at (http://
                                           approximately an order of magnitude                     recent event in May 2006 (a Model 727                 www.ntsb.gov/_layouts/ntsb.recsearch/
                                           reduction in the risk of a fuel tank                    airplane in India in 2006, a Model 737                Recommendation.aspx?Rec=A-00-106.
                                           explosion on anticipated flights with a                 airplane in Thailand in 2001, a Model                    • A–00–108—Repair of potentially
                                           latent failure of an FQIS circuit in the                747 airplane near New York in 1996,                   unsafe wiring conditions. Closed—
                                           center fuel tank. We estimate that the                  and a Model 737 airplane in the                       Acceptable Action: EAPAS/FTS
                                           periodic BITE checks in the cargo                       Philippines in 1991). It has now been                 Rulemaking. Safety Recommendation
                                           airplane alternative actions will result                ten years since the most recent event.                A–00–108 can be found at http://
                                           in a 75- to 90-percent reduction in the                   We agree that a significant                         www.ntsb.gov/_layouts/ntsb.recsearch/
                                           number of flights that operate with a                   improvement in fuel tank safety has                   Recommendation.aspx?Rec=A-00-108.
                                           latent in-tank failure that makes them                  occurred due to actions that have                        A4A noted that all applicable NTSB
                                           vulnerable to a single additional wiring                reduced the potential for ignition                    safety recommendations are closed with
                                           hot short failure creating an ignition                  sources associated with single failures               acceptable actions taken by the FAA.
                                           source in the center fuel tank. We                      of fuel pumps and fuel pump power                     A4A stated that none of the NTSB safety
                                           estimate that the proposed wire                         systems. That improvement alone                       recommendations called for the FAA to
                                           separation modification in the cargo                    would be expected to increase the                     address wire separation for the FQIS.
                                           airplane alternative actions will reduce                average interval between fuel tank                       We infer that A4A is requesting that
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                                           the risk of a hot short (and a resultant                ignition incidents to more than ten                   we withdraw the SNPRM because the
                                           ignition source) on flights that have a                 years. However, the fact that no                      NTSB considers the overall fuel tank
                                           latent in-tank failure by 50 to 75                      incidents have occurred since 2006 is                 safety issue to be adequately addressed
                                           percent. This estimated reduction in the                not statistically significant, and is not             by previous actions.
                                           risk on anticipated flights with a latent               sufficient to predict that additional                    We do not agree to withdraw the
                                           in-tank failure is sufficient to reduce the             events will not occur. In addition, even              SNPRM. A4A appears to have


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                                           19476                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations

                                           misunderstood NTSB Safety                               Unsafe Condition,’’ as well as in earlier             separation of the FQIS wiring from other
                                           Recommendation A–98–038 and the                         paragraphs in this discussion. We have                wiring is maintained. The Model 757
                                           NTSB’s acceptance of the FAA’s                          determined that it is necessary to                    CDCCL (28–AWL–05) contains a simple
                                           response to that safety recommendation.                 proceed with issuance of this final rule.             2-inch separation requirement as
                                           NTSB Safety Recommendation A–98–                                                                              originally proposed by Boeing. While
                                                                                                   Request To Remove Requirement for
                                           038 specifically called for the FAA to                                                                        Boeing has not proposed changes to the
                                                                                                   Corrective Actions for Cargo Airplanes
                                           require, in ‘‘airplanes with fuel quantity                                                                    Model 757 FQIS wire separation
                                           indication system (FQIS) wire                              A4A stated that the alternative wire               CDCCL, the corresponding CDCCL (28–
                                           installations that are co-routed with                   separation modifications allowed for                  AWL–05) for Model 737–700, –800, and
                                           wires that may be powered, the physical                 cargo airplanes would not meet the                    –900 airplanes has numerous additional
                                           separation and electrical shielding of                  ‘‘new design criteria.’’ (We assume that              provisions approving other design
                                           FQIS wires to the maximum extent                        A4A is referring to the wire separation               approaches (typically combinations of
                                           possible.’’ The NTSB classified that                    requirements for repairs and                          wire sleeving and smaller separation
                                           recommendation as ‘‘closed, acceptable                  modifications that are included in the                distances) that Boeing or operators
                                           action’’ after the FAA stated that it                   fuel tank system airworthiness                        proposed and that the FAA approved.
                                           would issue ADs to mandate FQIS                         limitations required by recent ADs for                Each time wire separation configuration
                                           protection on the high flammability                     the various Boeing models.) A4A stated                options were approved for Boeing,
                                           tanks of aircraft on which the                          that in the Model 757 service bulletin                alternative CDCCL wording was
                                           installation of FRM is not required by                  under development by Boeing, only                     approved as an AMOC with the AD that
                                           the Fuel Tank Flammability Reduction                    about ‘‘5 percent’’ of FQIS wires can be              required the addition of the CDCCLs to
                                           (FTFR) rule (73 FR 42444, July 21,                      separated from other systems by a                     operators’ maintenance programs. A
                                           2008). The communications between the                   distance of 2 inches, and that the                    similar AMOC will be granted for the
                                           NTSB and the FAA on Safety                              majority of the wire bundle relocation                approved modifications to the FQIS for
                                           Recommendation A–98–038 can be                          will achieve only up to 0.5-inch                      Model 757 airplanes.
                                           viewed at http://www.ntsb.gov/about/                    spacing. A4A stated that because the                     A4A also appears to have
                                           employment/_layouts/ntsb.recsearch/                     wire separation requirements are not                  misunderstood the reason that
                                           Recommendation.aspx?Rec=A-98-038.                       met, partial exemptions from the                      exemptions would be required to allow
                                           We have determined that it is necessary                 requirements of 14 CFR 25.981 are                     approval of the cargo airplane wire
                                           to proceed with issuance of this final                  required to allow approval of these wire              separation modification. Lack of a full 2
                                           rule.                                                   separation service bulletins. Based on                inches of wire separation in all of the
                                                                                                   the reduced separation distance and the               changed areas is not the reason an
                                           Request To Withdraw SNPRM:                              need for exemptions, A4A considered                   exemption is required. Rather, an
                                           Unjustified by Risk Assessment                          the proposed wire separation                          exemption is required because the
                                              A4A stated that the original                         requirements included in the cargo                    overall FQIS will not comply with 14
                                           equipment manufacturers (OEMs) and                      airplane alternative actions to be a                  CFR 25.901(c) and 25.981(a)(3) due to
                                           other regulatory agencies are having                    symbolic gesture with no significant                  the existing noncompliance of the
                                           difficulty calculating the true safety                  safety benefit, while at the same time                unchanged areas of the system. Because
                                           value associated with the proposed                      being expensive and intrusive. A4A                    those rules require a system-level safety
                                           FQIS AD. A4A stated that its position is                further stated that operators have                    analysis, we cannot find the changes to
                                           that all the unsafe conditions have been                reviewed the associated draft service                 the system compliant if a
                                           mitigated, operationally and across                     bulletins and are concerned about the                 noncompliance exists in the unchanged
                                           industry, and all previous rules have                   lack of a design target or adequate                   areas of the system.
                                           been effective. A4A added that, in light                rationale for the actions proposed by the                The proposed Boeing design uses
                                           of the operators’ financial and technical               FAA. Finally, A4A stated that Boeing                  sleeving over the wire bundles and
                                           investment to mitigate the unsafe                       had stated to them that Boeing does not               extensive retention features to provide a
                                           conditions in all areas, the SNPRM is                   understand what design changes the                    level of wire protection similar to the
                                           difficult to understand technically                     FAA wants or why the FAA considers                    protection that would be provided by a
                                           relative to the amount of mitigation that               there to be a safety issue.                           greater separation distance. The design
                                           would be required, in light of a true risk                 We infer that A4A is requesting that               measures are consistent with those
                                           assessment. A4A stated that the FAA is                  we remove the alternative actions for a               previously approved by the FAA in the
                                           alone in believing that a safety issue still            wire separation modification on cargo                 Model 737–700/800/900 CDCCL
                                           exists.                                                 airplanes because A4A believes the wire               mentioned previously.
                                              We infer that A4A is requesting that                 separation actions associated with the                   We consider the safety benefit
                                           we withdraw the SNPRM because it has                    cargo airplane alternative actions in the             provided by the proposed cargo airplane
                                           not been justified by a risk assessment                 SNPRM would have no significant                       alternative actions to be significant. The
                                           and because previously required actions                 safety benefit since inadequate physical              unsafe condition determination and the
                                           have adequately addressed the need for                  wire separation is provided.                          rationale and estimated safety benefit
                                           improvements in fuel tank safety.                          We do not agree to withdraw the                    for the cargo airplane alternative actions
                                              We do not agree to withdraw the                      SNPRM. A4A appears to have                            were discussed extensively with Boeing
                                           SNPRM. We provided a detailed                           misunderstood the intent of the FQIS                  in several meetings, and we consider
                                           response to similar comments and                        wire separation requirements added to                 that Boeing fully understands the FAA’s
                                           described the FAA’s risk assessment in                  the airworthiness limitations as a                    position on each of those aspects of the
                                           the SNPRM in the sections ‘‘Request to                  critical design configuration control                 proposal. The proposed requirement for
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                                           Withdraw NPRM (77 FR 12506, March                       limitation (CDCCL). The FQIS wire                     a periodic check through the built-in
                                           1, 2012): Unjustified by Risk,’’ ‘‘Request              separation CDCCL provides a set of wire               test equipment (BITE) of the FQIS
                                           to Withdraw NPRM (77 FR 12506,                          separation requirements that are                      processor is intended to identify and
                                           March 1, 2012): Not Supported by Risk                   intended to be used as a default when                 result in corrective actions for the
                                           Analysis,’’ and ‘‘Request to Withdraw                   modifying or repairing an aircraft to                 detectable fault conditions in the FQIS
                                           NPRM (77 FR 12506, March 1, 2012): No                   ensure that the intended level of                     in-tank wiring. We estimated that this


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                                                                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations                                         19477

                                           proposed requirement will result in a                   the level of risk on individual airplanes             flights with the condition we are
                                           75- to 90-percent reduction in the                      within the fleet. The FAA’s guidelines                concerned about (a latent failure plus
                                           number of flights that operate with a                   for assessing the total fleet risk related            flammable conditions inside the tank).
                                           latent in-tank failure that makes them                  to the unsafe condition are slightly                  The alternative actions for cargo
                                           vulnerable to a single additional wiring                different for cargo and passenger                     airplanes would also reduce the number
                                           hot short failure creating an ignition                  airplanes due to operational usage                    of expected flights with the condition
                                           source in the center fuel tank. The                     differences. In this case, however, the               we are concerned about, but to a lesser
                                           proposed FQIS wire separation                           total risk to the affected fleet is lower             degree. The FAA has determined that
                                           modification is intended to reduce the                  than the unsafe condition risk                        allowing a moderate number of cargo
                                           risk of a hot short of power onto center                guidelines for both passenger and cargo               flights per year (on average) with this
                                           tank FQIS circuits by physically                        airplanes. Total fleet risk is therefore not          condition provides an acceptable level
                                           isolating the portions of those circuits                the risk assessment element driving the               of safety. As part of making this
                                           that are outside of the tank in the areas               proposed actions.                                     determination, we noted that the level
                                           where those circuits are most vulnerable                   When assessing the level of risk on                of risk on the worst reasonably
                                           to damage and most easily separated.                    individual airplanes, the FAA considers               anticipated flights is similar to the level
                                           We did not propose to require                           the risk on the worst reasonably                      of risk for private and commercial pilots
                                           modifications of the wiring in the                      anticipated flights to ensure that the                flying normal category airplanes.
                                           electrical racks or in the cockpit areas                level of safety on each flight is                        We have not changed the final rule
                                           because of the difficulty involved in                   acceptable. Our individual flight risk                regarding this issue.
                                           accessing and achieving additional wire                 unsafe condition threshold is 1 × 10E–
                                                                                                                                                         Request To Require FQIS Modification
                                           separation in those areas, and in                       7 events (or a 1-in-10-million chance of
                                                                                                                                                         in all Fuel Tanks
                                           recognition that the FQIS processor                     a catastrophic event) per flight hour. In
                                           provides some beneficial circuit                        addition, the worst reasonably                           National Air Traffic Controllers
                                           isolation to protect against hot shorts in              anticipated flights should not be                     Association (NATCA) requested that we
                                           those areas. We estimated that the                      vulnerable to a single failure that causes            require changes to the FQIS to address
                                           proposed wire separation modification                   a fatal event, regardless of probability.             the potential ‘‘latent-plus-one-failure
                                           would reduce the risk of a hot short on                 There is no difference in the individual              scenario’’ in all fuel tanks, not just in
                                           flights that have a latent in-tank failure              flight risk unsafe condition criteria for             the center fuel tank.
                                           by 50 to 75 percent. Those estimates                    cargo airplanes and passenger airplanes                  NATCA stated that the failure
                                           were reviewed with Boeing, and Boeing                   because the operational differences are               condition that is the subject of the
                                           did not disagree with those estimates.                  not considered in this risk calculation.              SNPRM should be classified as a
                                           We have determined it is necessary to                      In this case, we are concerned about               ‘‘known’’ latent-plus-one-failure
                                           proceed with issuance of this final rule.               a latent failure inside the fuel tank that,           condition when applying the FAA
                                                                                                   in combination with an electrical short               Transport Airplane Directorate Policy
                                           Request To Remove Alternative Actions                   circuit in FQIS wiring outside of the                 Memorandum 2003–112–15, ‘‘SFAR
                                           for Cargo Airplanes                                     tank, could result in an electrical spark             88—Mandatory Action Decision
                                              Colin Edwards and an anonymous                       or arc in the tank. An electrical arc or              Criteria,’’ dated February 25, 2015
                                           commenter made no explicit request to                   spark in the fuel tank combined with                  (http://rgl.faa.gov/Regulatory_and_
                                           change the SNPRM, but objected to the                   flammable conditions in the fuel tank                 Guidance_Library/rgPolicy.nsf/0/
                                           proposed addition of alternative actions                could result in a fuel tank explosion.                dc94c3a46396950386256d5e006aed11/
                                           for cargo airplanes that would allow a                  The worst reasonably anticipated flights              $FILE/Feb2503.pdf). NATCA stated that
                                           design change that does not fully                       in this case are those that have both the             this would have the effect of classifying
                                           comply with the fuel tank system safety                 latent failure and flammable conditions               the failure condition as an unsafe
                                           requirements of 14 CFR part 25 (14 CFR                  in the tank. The manufacturer’s analysis              condition requiring corrective action in
                                           25.981(a)(3)) to be used to address the                 indicates that a significant number of                all affected fuel tanks regardless of
                                           unsafe condition. The commenters                        flights would be expected to occur with               flammability level.
                                           stated that it should not be acceptable                 these conditions in the life of the                      NATCA considered the combination
                                           to allow greater risk to exist on cargo                 affected fleet if no corrective action is             of a latent in-tank failure with electrical
                                           airplanes than that allowed for                         taken. For those flights, one additional              energy transmitted into the fuel tank via
                                           passenger airplanes.                                    failure—a short circuit between FQIS                  the FQIS wiring due to an additional
                                              We infer that the commenters propose                 wiring and power wiring—could cause                   failure outside of the tank to be a
                                           the elimination of the proposed                         a fuel tank explosion. Also, the                      ‘‘known’’ failure condition because that
                                           alternative corrective action for cargo                 probability of an explosion is between 1              failure condition was considered to be
                                           airplanes. We disagree with this request.               in a million and 1 in 10 million, per                 the most likely cause of the TWA Flight
                                           We determined that an acceptable level                  flight hour, which slightly exceeds the               800 Model 747 accident. (That accident
                                           of safety would be provided for the                     numerical unsafe condition guideline                  occurred on July 17, 1996, shortly after
                                           affected cargo airplanes, and explained                 for individual flight risk discussed                  takeoff from John F. Kennedy
                                           our position in depth in response to                    above.                                                International Airport in Jamaica, New
                                           similar comments in the SNPRM.                             An issue that violates one or more of              York.) NATCA concluded that because
                                           However, we will attempt to address the                 the individual flight risk guidelines                 the Model 757 FQIS is similar to that of
                                           commenters’ concerns by expanding on                    would normally require corrective                     the Model 747, both models are
                                           the explanation of our safety                           action that reduces the risk to a level               vulnerable to the same failure scenario.
                                           determination.                                          that is below the unsafe condition                    NATCA cited the unsafe condition
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                                              When assessing potential unsafe                      guidelines. However, in this case the                 statement for the SNPRM as evidence
                                           conditions on transport airplanes to                    FAA acknowledged that the cost of                     that the scenario should be classified as
                                           determine if corrective action is                       corrective action is high, and that the               ‘‘known.’’ NATCA pointed out that the
                                           necessary, the FAA assesses the total                   available corrective action (fuel tank                FAA issued AD 98–20–40, Amendment
                                           risk to the affected fleet of airplanes                 FRM systems) would reduce, but not                    39–10808 (63 FR 52147, September 30,
                                           exposed to the condition, and assesses                  eliminate, the number of expected                     1998), to address this issue for Model


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                                           19478                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations

                                           747 airplanes, and pointed out that the                 those differences on failure modes and                affected airplanes. Flights with
                                           FAA TARAM Handbook specifically                         failure probability. Based on our                     flammable conditions and a pre-existing
                                           states that Policy Memorandum 2003–                     determination that sufficient design                  latent in-tank FQIS failure are
                                           112–15 should be followed in                            differences exist between the Model 757               reasonably anticipated to occur in the
                                           determining whether corrective action                   and Model 747 FQIS designs to not                     life of the affected fleet. For those
                                           should be required for fuel tank safety                 classify the Model 757 FQIS latent-plus-              flights, a fuel tank explosion could
                                           concerns identified through SFAR 88.                    one-failure condition as ‘‘known,’’                   occur due to a single additional failure
                                             We disagree with the request to                       under the direction contained in the                  (hot short of power onto FQIS tank
                                           require modification of the FQIS in all                 policy memorandum, this AD addresses                  probe circuits). NATCA notes that four
                                           fuel tanks. We have determined that,                    that failure condition vulnerability only             fuel tank explosion events have
                                           under the policy contained in the policy                for the center fuel tank, which is the                occurred in fuel tanks that are classified
                                           memorandum, this failure condition for                  only high-flammability fuel tank on the               as low flammability.
                                           the Model 757 FQIS should not be                        Model 757.                                               We disagree with the request. We
                                           classified as ‘‘known.’’ The memo                          NATCA expressed a concern that the                 have determined that the proposed
                                           defines ‘‘known’’ failure conditions as                 FAA did not understand NATCA’s                        corrective actions (either installation of
                                           follows:                                                previous comment on this matter, and                  FRM or specific FQIS changes limited to
                                             [T]hose conditions which have occurred                stated that the FAA had not considered                the center fuel tank) represent a
                                           in-service and are likely to occur on other             the requirements of ‘‘Element 2.a)’’ from             reasonable, cost-effective method to
                                           products of the same or similar type design,            Policy Memorandum 2003–112–15,                        achieve a meaningful reduction in the
                                           and conditions which have been subject to               dated February 25, 2015. In fact, we had              risk of an accident due to potential FQIS
                                           mandatory corrective actions, following in-             addressed the requirements of ‘‘Element
                                           service findings, on products with a similar
                                                                                                                                                         fuel tank ignition sources.
                                                                                                   2.a)’’ in the response to the comments                   The service history of conventional
                                           design of fuel system.                                  under ‘‘Request to Revise Proposed AD                 unheated aluminum wing tanks that
                                              We agree that the Model 757 FQIS has                 Requirements to Apply to All Fuel                     contain Jet A fuel indicates that there
                                           the same high-level system architecture                 Tanks’’ of the SNPRM. The FAA                         would be little safety benefit by further
                                           and operating principles as those of the                understood the earlier comment and                    limiting the flammability of these tanks.
                                           Model 747 FQIS, resulting in                            understands the more recent comment,                  While NATCA expressed concern
                                           vulnerability to the same theoretical                   but has reached a different conclusion                because fuel vapor ignition events have
                                           latent-plus-one-failure scenario. There                 about the classification of the failure               occurred in wing fuel tanks, NATCA did
                                           are, however, significant differences in                condition under the guidance in the                   not differentiate service experience
                                           the details of the Model 757 FQIS                       policy memorandum. We classified the                  based on fuel type used (JP–4 versus Jet
                                           design that reduce the likelihood of the                Model 757 FQIS latent-plus-one-failure
                                                                                                                                                         A fuel).
                                           individual contributing failures. Those                 scenario as a theoretical vulnerability
                                                                                                                                                            Our review of the nine wing tank
                                           differences include the following:                      rather than a ‘‘known’’ combination of
                                              • Improved FQIS probe terminal                                                                             ignition events we know to have
                                                                                                   failures. Policy Memorandum 2003–
                                           connector block design;                                                                                       occurred on turbine-engine-powered
                                                                                                   112–15, dated February 25, 2015, calls
                                              • The use of wiring that is not silver                                                                     transport airplanes shows that five of
                                                                                                   for corrective action for theoretical
                                           plated and therefore does not create                    latent-plus-one-failure conditions only               the nine airplanes were using JP–4 fuel,
                                           silver sulfide deposits on the terminal                 in high-flammability fuel tanks.                      and this type of fuel is no longer used
                                           blocks;                                                 Contrary to the assertion in the NATCA                except on an emergency basis in the
                                              • The use of improved wire types and                 comment, the acknowledgement of the                   U.S. Use of JP–4 fuel in other parts of
                                           wiring installation practices outside of                scenario as theoretically possible and                the world is also relatively rare, and is
                                           the fuel tanks; and                                     the consequent AD proposal to address                 normally limited to areas with
                                              • The use of a system processor that                 the scenario in the high flammability                 extremely cold airport conditions. Three
                                           provides significant isolation of the tank              center fuel tank do not automatically                 of the remaining four events were
                                           probe circuits from the indication and                  drive classification of the failure as                caused by external heating of the wing
                                           power circuits of the FQIS.                             ‘‘known’’ under the policy                            by engine fires, and the remaining event
                                              We therefore did not consider that the               memorandum. We have not changed                       occurred on the ground during
                                           FQIS designs for the Model 747 and                      this final rule regarding this issue.                 maintenance. To date, there have been
                                           Model 757 were so similar that the                                                                            no fuel tank explosions in conventional
                                           Model 757 FQIS design should be                         Request To Address Unsafe Condition                   unheated aluminum wing tanks fueled
                                           considered to have a ‘‘known’’ latent-                  in All Fuel Tanks, With or Without                    with Jet A fuel that have resulted in any
                                           plus-one-failure condition vulnerability                FRM                                                   fatalities.
                                           as defined in the policy memorandum.                       NATCA requested that we require                       The flammability characteristics of
                                           The provisions in the above definition                  design changes to the FQIS to address                 JP–4 fuel results in the fuel tanks being
                                           for classifying a failure condition as                  the potential latent-plus-one-failure                 flammable a significant portion of the
                                           ‘‘known’’ based on the existence of a                   scenario in all fuel tanks of all Model               time when an airplane is in flight. This
                                           similar design were intended to allow                   757 airplanes, regardless whether FRM                 is not the case for wing tanks containing
                                           the FAA to evaluate the degree of                       is installed. NATCA stated that the                   Jet A fuel. Therefore, based on the low
                                           similarity in the design, and to make                   minimum performance standards for                     fleet average flammability of the Model
                                           discretionary judgments in determining                  FRM contained in 14 CFR part 25 allow                 757 wing fuel tanks and on the specific
                                           that a failure condition that is believed               flights to occur with flammable                       features of the Model 757 FQIS design,
                                           to have occurred (and/or was addressed                  conditions in tanks that are required to              we have determined that the latent-plus-
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                                           by AD action) in one specific design                    incorporate FRM due to system                         one vulnerability that exists in the
                                           should be classified as ‘‘known’’ in a                  performance as designed and due to                    Model 757 wing tank FQIS is not an
                                           different specific design. The                          system failures. In addition, time-                   unsafe condition requiring corrective
                                           application of that discretion would be                 limited dispatch with an inoperative                  action on in-service airplanes.
                                           expected to involve evaluation of design                FRM has been allowed in the master                       We have not changed this final rule
                                           detail differences and the effects of                   minimum equipment list (MMEL) for                     regarding this issue.


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                                                                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations                                         19479

                                           Request To Require Design Changes for                   requirement for a proposed design                     time to allow FedEx’s proposed
                                           Full Compliance with Airworthiness                      intended as corrective action for an                  alternative procedure. However, under
                                           Regulations                                             SFAR 88 issue. We therefore consider                  the provisions of paragraph (i) of this
                                              NATCA requested that we require                      that the applicant may petition for an                AD, we will consider requests for
                                           design changes to the FQIS that would                   exemption and propose a noncompliant                  approval of alternative procedures, if
                                           bring that system into full compliance                  design change, and the FAA may                        sufficient data are submitted to
                                           with the applicable airworthiness                       approve and issue an AD to require a                  substantiate that the change would
                                           regulations. NATCA stated that the                      noncompliant design change. Boeing’s                  provide an acceptable level of safety.
                                           failure condition that is the subject of                FRM design change for the Model 757                   We have not changed this final rule
                                           the SNPRM represents a noncompliance                    was approved some time ago. We have                   regarding this request.
                                           of the type design with the requirements                determined that for Model 757
                                                                                                   airplanes, installation of FRM, instead               Request To Reduce Compliance Time
                                           of 14 CFR 25.901(c) and 25.981(a)(3),
                                                                                                   of FQIS design changes, represents a                     NATCA requested that we reduce the
                                           even for low-flammability fuel tanks.
                                                                                                   reasonable, cost-effective method to                  compliance time to 5 years or less.
                                           NATCA stated that the proposed
                                                                                                   achieve a meaningful overall reduction                NATCA noted that the proposed 72-
                                           corrective actions would not bring the
                                                                                                   in the risk of an accident due to fuel                month compliance time would result in
                                           airplane design into compliance with
                                                                                                   tank ignition events. We therefore                    a corrective action deadline that is
                                           those regulations ‘‘as required by SFAR
                                                                                                   excluded airplanes with FRM installed                 approximately 27 years after the TWA
                                           88 and SFAR 88 Policy published by the
                                                                                                   from the applicability of this AD.
                                           FAA as Mandatory Corrective Action                                                                            Flight 800 accident. NATCA stated that
                                           criteria in FAA Policy Statement No.                    Request To Mandate Compliance with                    such a long delay in action is not in the
                                           2003–112–15.’’ NATCA added that the                     Airworthiness Regulations for Newly                   public interest.
                                           proposed alternative corrective actions                 Produced Airplanes                                       We disagree with the request to
                                           for cargo airplanes do not comply with                     NATCA requested that we require                    reduce the compliance time, which we
                                           those regulations because the alternative               newly produced airplanes to be in                     have determined is necessary to give
                                           actions do not fully eliminate the                      compliance with 14 CFR 25.901,                        operators adequate time to prepare for
                                           potential for the failure condition that is             25.981(a), and 25.981(b). NATCA                       and perform the required modifications
                                           addressed by the SNPRM.                                 expressed concern that nearly 20 years                without excessive disruption of
                                              We disagree with the request. SFAR                   after the TWA Flight 800 accident,                    operations. We had initially proposed
                                           88, as modified by Amendment 21–82,                     manufacturers have been allowed to                    60 months, but extended that to 72
                                           and Policy Memorandum 2003–112–15,                      continue production of airplanes                      months in response to operator
                                           dated February 25, 2003, do not                         without making changes to eliminate                   comments, which included extension
                                           specifically require noncompliant                       the FQIS latent-plus-one-failure                      requests of up to 108 months. NATCA
                                           designs discovered through SFAR 88 to                   scenario, and that the FAA has granted                made a similar comment to the NPRM
                                           be brought into compliance. As                          exemptions to approve certain design                  (77 FR 12506, March 1, 2012),
                                           originally issued, SFAR 88 required                     changes without fully addressing the                  requesting a reduction in the
                                           design approval holders to develop the                  issue.                                                compliance time to 36 months, and the
                                           corrective actions necessary to bring any                  We disagree with the request. This AD              FAA provided its response in the
                                           noncompliant design fuel system                         applies only to certain Model 757 series              SNPRM under ‘‘Request to Reduce
                                           features into compliance. However,                      airplanes, and the Model 757 is out of                Compliance Time.’’ We have not
                                           SFAR 88 did not dictate that the FAA                    production. The comment is therefore                  changed this final rule regarding this
                                           require a given corrective action. In fact,             outside of the scope of this AD. We have              issue.
                                           the FAA later published Amendment                       not changed the final rule regarding this
                                           21–82, ‘‘Equivalent Safety Provisions for               issue.                                                Statement Regarding Compliance Time
                                           Fuel Tank System Fault Tolerance                                                                              for Wire Separation
                                           Evaluations (SFAR 88),’’ to clarify that                Request To Allow Alternative
                                           the FAA would accept SFAR 88 reports                    Procedure for BITE Check                                 FedEx stated that without service
                                           that do not provide corrective actions                    FedEx proposed that we revise                       information for the wire separation, it
                                           that directly comply with 14 CFR                        paragraph (h)(1) of the SNPRM to allow                cannot effectively determine whether
                                           25.981(a)(3) provided any aspects that                  use of the FQIS BITE check procedure                  the proposed 72-month compliance time
                                           do not comply are compensated for by                    in its airplane maintenance manual                    is acceptable.
                                           factors that provide an equivalent level                (AMM) as an alternative to the                           We had previously determined, as
                                           of safety. The FAA used the                             procedure in Boeing Service Bulletin                  specified in the SNPRM, that the work
                                           introduction of flammability reduction                  757–28–0136, dated June 5, 2014, which                involved for the cargo airplane wire
                                           in place of corrective action for a                     does not apply to FedEx’s fleet. We                   separation modification would take 230
                                           specific ignition source as an example of               assume this is because FedEx operates                 work-hours, and a compliance time of
                                           a potentially acceptable compensating                   some airplanes that were converted to a               72 months would be adequate for
                                           factor.                                                 cargo configuration using a non-Boeing                operators to perform the modification
                                              Also, while the normal certification                 supplemental type certificate.                        on their affected fleets. Boeing has since
                                           process requires proposed design                          We disagree with the request. FedEx’s               provided an updated estimate of 74
                                           changes to be compliant with the                        comment did not provide adequate                      work-hours for the alternative
                                           applicable regulations, applicants are                  information to show that its AMM                      modification for cargo airplanes. We
                                           permitted under 14 CFR part 11 to                       procedure is equivalent to the procedure              have revised the cost estimate
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                                           petition for an exemption from any FAA                  described in Boeing Service Bulletin                  accordingly in this final rule, but since
                                           regulatory requirement. Policy                          757–28–0136, dated June 5, 2014.                      this change reduces the work-hour
                                           Memorandum 2003–112–15, dated                           FedEx’s comment also did not identify                 estimate, it is not necessary to adjust the
                                           February 25, 2003, did not state that the               the fault conditions for which dispatch               compliance time to accommodate the
                                           FAA would not consider a petition for                   would be prohibited. We therefore do                  workload for this action for cargo
                                           exemption from an airworthiness                         not have sufficient information at this               operators.


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                                           19480                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations

                                           Request To Remove Reference to ‘‘Fuel                   Request To Delay Final Rule Pending                   AD, operators must perform the first
                                           Tank Systems’’                                          New Service Information                               BITE check before flight after the
                                             Paragraph (g) of the SNPRM would                         Boeing requested that we delay                     conversion. In reviewing the proposed
                                           have required modification of ‘‘the FQIS                issuance of the final rule pending                    requirements after publication of the
                                           wiring or fuel tank systems.’’ Boeing                   issuance of new service information that              SNPRM, we recognized that operators
                                           asked that we remove reference to ‘‘fuel                would specifically define an acceptable               might interpret the requirements as
                                           tank systems’’ in this proposed                         wiring configuration that complies with               allowing a delay in the decision to
                                           requirement because a fuel tank system                  the proposed requirements.                            exercise the cargo airplane alternative
                                           modification could be done as an                           We disagree with the request because               until late in the compliance period. That
                                           AMOC.                                                   the referenced service information was                is not the literal meaning of the
                                             We agree with the commenter’s                         not available at the time we were ready               proposed language of the requirement,
                                           request and rationale. We have removed                  to publish the final rule, and we cannot              and was not the FAA’s intent. However,
                                           the references to ‘‘fuel tank systems’’                 reliably predict the time that service                we determined that we should clarify
                                           throughout the preamble and in                          information will be issued by Boeing.                 the language of paragraph (h) of this AD
                                           paragraph (g) of this AD.                               We do not consider it in the public                   regarding the required timing for the
                                                                                                   interest to further delay this rulemaking.            first BITE check if an operator chooses
                                           Request To Clarify Condition Requiring                                                                        to exercise the cargo airplane
                                                                                                   We have determined that it is necessary
                                           Repair                                                                                                        alternative.
                                                                                                   to proceed with issuing the final rule as
                                              Boeing requested that we revise                      proposed. Operators may, however,                     Conclusion
                                           paragraph (h)(1) of the SNPRM to                        request approval under the provisions of
                                           specify that repair is required for any                 paragraph (i) of this AD to use a future                We reviewed the relevant data,
                                           ‘‘nondispatchable’’ fault code recorded                 approved service bulletin, if developed,              considered the comments received, and
                                           before or as a result of the BITE check.                as an AMOC with the requirements of                   determined that air safety and the
                                           (The SNPRM would have required                          this AD, or we may approve the service                public interest require adopting this AD
                                           repair for any fault code.) Boeing                      bulletin as a global AMOC.                            with the changes described previously
                                           requested this change to make the repair                                                                      and minor editorial changes. We have
                                           requirement consistent with the BITE                    Statement Regarding Unsafe Condition                  determined that these minor changes:
                                           check service information referenced in                    Boeing stated that it has accepted the               • Are consistent with the intent that
                                           the SNPRM (Boeing Service Bulletin                      FAA’s requirement to provide service                  was proposed in the SNPRM for
                                           757–28–0136, dated June 5, 2014).                       information defining an acceptable wire               correcting the unsafe condition; and
                                              We agree with the request. The intent                separation modification, but, based on                  • Do not add any additional burden
                                           of the SNPRM was to require correction                  previously provided analysis,                         upon the public than was already
                                           only of faults identified as                            maintained that the risk level is less                proposed in the SNPRM.
                                           ‘‘nondispatchable.’’ The SNPRM used                     than extremely improbable. As asserted                  We also determined that these
                                           the terminology ‘‘as applicable’’ to                    in earlier comments, Boeing considers                 changes will not increase the economic
                                           indicate this intent, but we agree that                 the design of the affected airplanes safe             burden on any operator or increase the
                                           further clarification is appropriate. We                and the proposed requirements                         scope of this AD.
                                           have revised paragraph (h)(1) in this AD                therefore unnecessary.                                Related Service Information Under 1
                                           as requested by the commenter.                             We disagree with Boeing’s assertions
                                                                                                                                                         CFR Part 51
                                                                                                   for the reasons discussed extensively in
                                           Request To Clarify End Point for FQIS                                                                           We have reviewed Boeing Service
                                                                                                   our response to Boeing’s similar
                                           Wire Separation                                                                                               Bulletin 757–28–0136, dated June 5,
                                                                                                   comment in the SNPRM. The FAA’s
                                             Paragraph (h)(2) of the SNPRM                         response to Boeing’s assertion is                     2014, which describes procedures for a
                                           specified that the FQIS wiring                          covered in the response to comments in                BITE check (check of built-in test
                                           separation was to be done on the wiring                 the SNPRM under ‘‘Request to                          equipment). This service information is
                                           that runs between the FQIS processor                    Withdraw NPRM (77 FR 12506, March                     reasonably available because the
                                           and the center fuel tank. Boeing                        1, 2012): Unjustified by Risk.’’                      interested parties have access to it
                                           requested that we change ‘‘the center                                                                         through their normal course of business
                                           fuel tank’’ to ‘‘the center fuel tank wall              Additional Change Made to This AD                     or by the means identified in the
                                           penetrations.’’ Boeing requested this                      We have revised the introductory text              ADDRESSES section.
                                           change to clarify the end point for the                 to paragraph (h) of this AD to clarify
                                                                                                   that the alternative modification for                 Costs of Compliance
                                           FQIS wire separation.
                                             We agree with the request. Boeing’s                   cargo airplanes must be accompanied by                  We estimate that this AD affects 167
                                           suggestion is consistent with the intent                periodic BITE checks started within 6                 airplanes of U.S. registry. This estimate
                                           of this AD, and improves the clarity of                 months after the effective date of this               includes 148 cargo airplanes and 19
                                           the requirement. We have revised                        AD. And, for airplanes converted to an                non-air-carrier passenger airplanes. We
                                           paragraph (h)(2) in this AD to                          all-cargo configuration more than 6                   estimate the following costs to comply
                                           incorporate Boeing’s request.                           months after the effective date of this               with this AD:

                                                                                    ESTIMATED COSTS: BASIC REQUIREMENT FOR ALL AIRPLANES
                                                                                                                                                                                           Cost per prod-
                                                                     Action                                                       Labor cost                               Parts cost
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                                                                                                                                                                                                uct

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




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                                                                      Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations                                                             19481

                                                                                    ESTIMATED COSTS: BASIC REQUIREMENT FOR ALL AIRPLANES—Continued
                                                                                                                                                                                                                 Cost per prod-
                                                                            Action                                                                  Labor cost                                  Parts cost            uct

                                                                                                           Estimated Costs: Alternative Actions for All Airplanes

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

                                                                                                        Estimated Costs: Alternative Actions for Cargo Airplanes

                                           Wire separation ..........................................................       74 work-hours × $85 per hour = $6,290 ...................                  10,000    $16,290.

                                           FQIS BITE check (required with wire separation al-                               1 work-hour × $85 per hour = $85 ............................                    0   $85 per check
                                             ternative actions).                                                                                                                                                   (4 checks
                                                                                                                                                                                                                   per year).



                                              Existing regulations already require                                   For the reasons discussed above, I                       approved by the FAA as compliant with the
                                           that air-carrier passenger airplanes be                                 certify that this AD:                                      Fuel Tank Flammability Reduction (FTFR)
                                           equipped with FRM by December 26,                                         (1) Is not a ‘‘significant regulatory                    rule (73 FR 42444, July 21, 2008)
                                                                                                                   action’’ under Executive Order 12866,                      requirements of 14 CFR 25.981(b) or 14 CFR
                                           2017. We therefore assume that the FRM
                                                                                                                     (2) Is not a ‘‘significant rule’’ under                  26.33(c)(1).
                                           installation specified in paragraph (g) of
                                           this AD will be done on only the 19                                     DOT Regulatory Policies and Procedures                     (d) Subject
                                           affected non-air-carrier passenger                                      (44 FR 11034, February 26, 1979),                            Joint Aircraft System Component (JASC)
                                           airplanes, for an estimated passenger                                     (3) Will not affect intrastate aviation                  Code 7397: Engine fuel system wiring.
                                           fleet cost of $7,299,800. We also assume                                in Alaska, and
                                                                                                                     (4) Will not have a significant                          (e) Unsafe Condition
                                           that the operators of the 148 affected
                                                                                                                   economic impact, positive or negative,                        This AD was prompted by fuel system
                                           cargo airplanes would choose the less                                                                                              reviews conducted by the manufacturer. We
                                           costly actions specified in paragraph (h)                               on a substantial number of small entities
                                                                                                                   under the criteria of the Regulatory                       are issuing this AD to prevent ignition
                                           of this AD, at an estimated cost of                                                                                                sources inside the center fuel tank, which, in
                                           $2,410,920 for the wire separation                                      Flexibility Act.                                           combination with flammable fuel vapors,
                                           modification, plus $50,320 annually for                                 List of Subjects in 14 CFR Part 39                         could result in a fuel tank explosion and
                                           the BITE checks.                                                                                                                   consequent loss of the airplane.
                                                                                                                     Air transportation, Aircraft, Aviation
                                           Authority for This Rulemaking                                           safety, Incorporation by reference,                        (f) Compliance
                                              Title 49 of the United States Code                                   Safety.                                                       Comply with this AD within the
                                                                                                                                                                              compliance times specified, unless already
                                           specifies the FAA’s authority to issue                                  Adoption of the Amendment                                  done.
                                           rules on aviation safety. Subtitle I,                                     Accordingly, under the authority
                                           section 106, describes the authority of                                                                                            (g) Modification
                                                                                                                   delegated to me by the Administrator,
                                           the FAA Administrator. Subtitle VII:                                    the FAA amends 14 CFR part 39 as                              Within 72 months after the effective date
                                           Aviation Programs, describes in more                                    follows:
                                                                                                                                                                              of this AD, modify the fuel quantity
                                           detail the scope of the Agency’s                                                                                                   indication system (FQIS) wiring to prevent
                                           authority.                                                                                                                         development of an ignition source inside the
                                                                                                                   PART 39—AIRWORTHINESS
                                              We are issuing this rulemaking under                                                                                            center fuel tank, using a method approved in
                                                                                                                   DIRECTIVES                                                 accordance with the procedures specified in
                                           the authority described in Subtitle VII,
                                                                                                                                                                              paragraph (i) of this AD.
                                           Part A, Subpart III, Section 44701:                                     ■ 1. The authority citation for part 39
                                           ‘‘General requirements.’’ Under that                                    continues to read as follows:                              (h) Alternative Actions for Cargo Airplanes
                                           section, Congress charges the FAA with                                      Authority: 49 U.S.C. 106(g), 40113, 44701.                For airplanes used exclusively for cargo
                                           promoting safe flight of civil aircraft in                                                                                         operations: As an alternative to the
                                           air commerce by prescribing regulations                                 § 39.13      [Amended]                                     requirements of paragraph (g) of this AD, do
                                           for practices, methods, and procedures                                  ■ 2. The FAA amends § 39.13 by adding                      the actions specified in paragraphs (h)(1) and
                                           the Administrator finds necessary for                                                                                              (h)(2) of this AD, using methods approved in
                                                                                                                   the following new airworthiness
                                           safety in air commerce. This regulation                                                                                            accordance with the procedures specified in
                                                                                                                   directive (AD):                                            paragraph (i) of this AD. To exercise this
                                           is within the scope of that authority                                                                                              alternative, operators must perform the first
                                           because it addresses an unsafe condition                                2016–07–07 The Boeing Company:
                                                                                                                                                                              inspection required under paragraph (h)(1) of
                                           that is likely to exist or develop on                                       Amendment 39–18452; Docket No.
                                                                                                                                                                              this AD within 6 months after the effective
                                           products identified in this rulemaking                                      FAA–2012–0187; Directorate Identifier
                                                                                                                                                                              date of this AD. To exercise this alternative
                                                                                                                       2011–NM–094–AD.
                                           action.                                                                                                                            for airplanes returned to service after
                                                                                                                   (a) Effective Date                                         conversion of the airplane from a passenger
                                           Regulatory Findings                                                                                                                configuration to an all-cargo configuration
                                                                                                                     This AD is effective May 10, 2016.
                                             This AD will not have federalism                                                                                                 more than 6 months after the effective date
                                           implications under Executive Order                                      (b) Affected ADs                                           of this AD, operators must perform the first
                                           13132. This AD will not have a                                            None.                                                    inspection required under paragraph (h)(1) of
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                                                                                                                                                                              this AD prior to further flight after the
                                           substantial direct effect on the States, on                             (c) Applicability                                          conversion.
                                           the relationship between the national                                      This AD applies to The Boeing Company                      (1) Within 6 months after the effective date
                                           government and the States, or on the                                    Model 757–200, –200PF, –200CB, and –300                    of this AD, record the existing fault codes
                                           distribution of power and                                               series airplanes; certificated in any category;            stored in the FQIS processor and then do a
                                           responsibilities among the various                                      except airplanes equipped with a                           BITE check (check of built-in test equipment)
                                           levels of government.                                                   flammability reduction means (FRM)                         of the FQIS, in accordance with the



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                                           19482                Federal Register / Vol. 81, No. 65 / Tuesday, April 5, 2016 / Rules and Regulations

                                           Accomplishment Instructions of Boeing                   Management, P. O. Box 3707, MC 2H–65,                 Rond Point Maurice Bellonte, 31707
                                           Service Bulletin 757–28–0136, dated June 5,             Seattle, WA 98124–2207; telephone 206–                Blagnac Cedex, France; telephone +33 5
                                           2014. If any nondispatchable fault code is              544–5000, extension 1; fax 206–766–5680;              61 93 36 96; fax +33 5 61 93 44 51; email
                                           recorded prior to the BITE check or as a                Internet https://www.myboeingfleet.com.
                                           result of the BITE check, before further flight,
                                                                                                                                                         account.airworth-eas@airbus.com;
                                                                                                      (4) You may view this service information
                                           do all applicable repairs, and repeat the BITE          at FAA, Transport Airplane Directorate, 1601          Internet http://www.airbus.com. You
                                           check until a successful test is performed              Lind Avenue SW., Renton, WA. For                      may view this referenced service
                                           with no nondispatchable fault found, in                 information on the availability of this               information at the FAA, Transport
                                           accordance with the Accomplishment                      material at the FAA, call 425–227–1221.               Airplane Directorate, 1601 Lind Avenue
                                           Instructions of Boeing Service Bulletin 757–               (5) You may view this service information          SW., Renton, WA. For information on
                                           28–0136, dated June 5, 2014. Repeat these               that is incorporated by reference at the              the availability of this material at the
                                           actions thereafter at intervals not to exceed           National Archives and Records                         FAA, call 425–227–1221. It is also
                                           750 flight hours.                                       Administration (NARA). For information on
                                             (2) Within 72 months after the effective                                                                    available on the Internet at http://
                                                                                                   the availability of this material at NARA, call
                                           date of this AD, modify the airplane by                                                                       www.regulations.gov by searching for
                                                                                                   202–741–6030, or go to http://
                                           separating FQIS wiring that runs between the            www.archives.gov/federal-register/cfr/ibr-            and locating Docket No. FAA–2015–
                                           FQIS processor and the center fuel tank wall            locations.html.                                       6537.
                                           penetrations, including any circuits that pass
                                           through a main fuel tank, from other airplane             Issued in Renton, Washington, on March              Examining the AD Docket
                                           wiring that is not intrinsically safe.                  21, 2016.
                                                                                                                                                           You may examine the AD docket on
                                                                                                   Michael Kaszycki,                                     the Internet at http://
                                           (i) Alternative Methods of Compliance
                                           (AMOCs)                                                 Acting Manager, Transport Airplane                    www.regulations.gov by searching for
                                                                                                   Directorate, Aircraft Certification Service.          and locating Docket No. FAA–2015–
                                              (1) The Manager, Seattle Aircraft
                                                                                                   [FR Doc. 2016–07150 Filed 4–4–16; 8:45 am]            6537; or in person at the Docket
                                           Certification Office (ACO), FAA, has the
                                           authority to approve AMOCs for this AD, if              BILLING CODE 4910–13–P                                Management Facility between 9 a.m.
                                           requested using the procedures found in 14                                                                    and 5 p.m., Monday through Friday,
                                           CFR 39.19. In accordance with 14 CFR 39.19,                                                                   except Federal holidays. The AD docket
                                           send your request to your principal inspector           DEPARTMENT OF TRANSPORTATION                          contains this AD, the regulatory
                                           or local Flight Standards District Office, as                                                                 evaluation, any comments received, and
                                           appropriate. If sending information directly            Federal Aviation Administration
                                           to the manager of the ACO, send it to the
                                                                                                                                                         other information. The street address for
                                           attention of the person identified in                                                                         the Docket Operations office (telephone
                                                                                                   14 CFR Part 39
                                           paragraph (j) of this AD. Information may be                                                                  800–647–5527) is Docket Management
                                           emailed to: 9-ANM-Seattle-ACO-AMOC-                     [Docket No. FAA–2015–6537; Directorate                Facility, U.S. Department of
                                           Requests@faa.gov.                                       Identifier 2014–NM–154–AD; Amendment                  Transportation, Docket Operations, M–
                                              (2) Before using any approved AMOC,                  39–18457; AD 2016–07–12]                              30, West Building Ground Floor, Room
                                           notify your appropriate principal inspector,                                                                  W12–140, 1200 New Jersey Avenue SE.,
                                           or lacking a principal inspector, the manager           RIN 2120–AA64
                                                                                                                                                         Washington, DC.
                                           of the local flight standards district office/
                                           certificate holding district office.                    Airworthiness Directives; Airbus                      FOR FURTHER INFORMATION CONTACT:
                                              (3) An AMOC that provides an acceptable              Airplanes                                             Sanjay Ralhan, Aerospace Engineer,
                                           level of safety may be used for any repair,                                                                   International Branch, ANM–116,
                                           modification, or alteration required by this            AGENCY:  Federal Aviation                             Transport Airplane Directorate, FAA,
                                           AD if it is approved by the Boeing                      Administration (FAA), Department of                   1601 Lind Avenue SW., Renton, WA
                                           Commercial Airplanes Organization                       Transportation (DOT).                                 98057–3356; telephone 425–227–1405;
                                           Designation Authorization (ODA) that has                ACTION: Final rule.                                   fax 425–227–1149.
                                           been authorized by the Manager, Seattle
                                           ACO, to make those findings. To be                      SUMMARY:    We are adopting a new                     SUPPLEMENTARY INFORMATION:
                                           approved, the repair method, modification               airworthiness directive (AD) for certain
                                           deviation, or alteration deviation must meet
                                                                                                                                                         Discussion
                                                                                                   Airbus Model A318, A319, A320, and
                                           the certification basis of the airplane, and the                                                                 We issued a notice of proposed
                                           approval must specifically refer to this AD.
                                                                                                   A321 series airplanes. This AD was
                                                                                                   prompted by reports of cracking of the                rulemaking (NPRM) to amend 14 CFR
                                           (j) Related Information                                 aft fixed fairing (AFF) of the pylons due             part 39 by adding an AD that would
                                              For more information about this AD,                  to fatigue damage of the structure. This              apply to certain Airbus Model A318,
                                           contact Jon Regimbal, Aerospace Engineer,               AD requires repetitive inspections for                A319, A320, and A321 series airplanes.
                                           Propulsion Branch, ANM–140S, FAA, Seattle               damage and cracking of the AFF of the                 The NPRM published in the Federal
                                           ACO, 1601 Lind Avenue SW., Renton, WA                   pylons, and repair if necessary. We are               Register on November 30, 2015 (80 FR
                                           98057–3356; phone: 425–917–6506; fax: 425–
                                                                                                   issuing this AD to detect and correct                 74729) (‘‘the NPRM’’).
                                           917–6590; email: jon.regimbal@faa.gov.                                                                           The European Aviation Safety Agency
                                                                                                   damage and cracking of the AFF of the
                                           (k) Material Incorporated by Reference                  pylons, which could result in                         (EASA), which is the Technical Agent
                                              (1) The Director of the Federal Register             detachment of a pylon and consequent                  for the Member States of the European
                                           approved the incorporation by reference                 reduced structural integrity of the                   Union, has issued EASA Airworthiness
                                           (IBR) of the service information listed in this         airplane.                                             Directive 2014–0154, dated July 2, 2014
                                           paragraph under 5 U.S.C. 552(a) and 1 CFR                                                                     (referred to after this as the Mandatory
                                           part 51.                                                DATES:  This AD becomes effective May                 Continuing Airworthiness Information,
                                              (2) You must use this service information            10, 2016.                                             or ‘‘the MCAI’’), to correct an unsafe
                                           as applicable to do the actions required by               The Director of the Federal Register                condition for certain Airbus Model
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                                           this AD, unless the AD specifies otherwise.             approved the incorporation by reference               A318, A319, A320, and A321 series
                                              (i) Boeing Service Bulletin 757–28–0136,             of a certain publication listed in this AD
                                           dated June 5, 2014.
                                                                                                                                                         airplanes. The MCAI states:
                                                                                                   as of May 10, 2016.
                                              (ii) Reserved.                                                                                               On aeroplanes equipped with post-mod
                                              (3) For service information identified in            ADDRESSES: For service information                    33844 CFM pylons, several operators have
                                           this AD, contact Boeing Commercial                      identified in this final rule, contact                reported cracks on the Aft Fixed Fairing
                                           Airplanes, Attention: Data & Services                   Airbus, Airworthiness Office—EIAS, 1                  (AFF). After material analysis, it appears that



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Document Created: 2018-02-07 13:53:53
Document Modified: 2018-02-07 13:53:53
CategoryRegulatory Information
CollectionFederal Register
sudoc ClassAE 2.7:
GS 4.107:
AE 2.106:
PublisherOffice of the Federal Register, National Archives and Records Administration
SectionRules and Regulations
ActionFinal rule.
DatesThis AD is effective May 10, 2016.
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 Citation81 FR 19472 
RIN Number2120-AA64
CFR AssociatedAir Transportation; Aircraft; Aviation Safety; Incorporation by Reference and Safety

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