80 FR 27074 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 91 (May 12, 2015)

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400 and 747-400F series airplanes. This AD was prompted by reports of cracking in the main equipment center (MEC) drip shield and exhaust plenum. This AD requires installing a fiberglass reinforcing overcoat on the MEC drip shield. We are issuing this AD to prevent water penetration into the MEC, which could result in an electrical short and potential loss of several functions essential for safe flight.

[Federal Register Volume 80, Number 91 (Tuesday, May 12, 2015)]
[Rules and Regulations]
[Pages 27074-27077]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-10069]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0429; Directorate Identifier 2014-NM-039-AD; 
Amendment 39-18151; AD 2015-09-05]
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 747-400 and 747-400F series airplanes. This AD 
was prompted by reports of cracking in the main equipment center (MEC) 
drip shield and exhaust plenum. This AD requires installing a 
fiberglass reinforcing overcoat on the MEC drip shield. We are issuing 
this AD to prevent water penetration into the MEC, which could result 
in an electrical short and potential loss of several functions 
essential for safe flight.

DATES: This AD is effective June 16, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 16, 
2015.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707,

[[Page 27075]]

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-2014-0429.

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-2014-
0429; 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: Francis Smith, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-
3356; telephone: 425-917-6596; fax: 425-917-6590; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain The Boeing Company 
Model 747-400 and 747-400F series airplanes. The NPRM published in the 
Federal Register on July 9, 2014 (79 FR 38799). The NPRM was prompted 
by reports of cracking in the MEC drip shield and exhaust plenum. The 
NPRM proposed to require installing a fiberglass reinforcing overcoat 
on the MEC drip shield. We are issuing this AD to prevent water 
penetration into the MEC, which could result in an electrical short and 
potential loss of several functions essential for safe flight.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM (79 
FR 38799, July 9, 2014) and the FAA's response to each comment.

Request To Use Later Revision of the Service Information

    Boeing requested that the latest pending revision of Boeing Alert 
Service Bulletin 747-25A3640 (i.e., Revision 1), be added to the NPRM 
(79 FR 38799, July 9, 2014). Boeing stated that illustrations shown in 
Figure 1 of the latest service information will clarify the repair 
location of the MEC drip shield.
    We disagree with the commenter's request. We cannot include 
unapproved service information in the final rule as this would violate 
the Office of the Federal Register regulations for approving materials 
that are incorporated by reference. However, operators may request 
approval to use a later revision of the referenced service information 
as an alternative method of compliance (AMOC) under the provisions of 
paragraph (h)(1) of this AD. We have not changed this AD in this 
regard.

Request To Include Inspection and Repair Procedures for Cracks in the 
MEC Drip Shield

    United Parcel Service (UPS) requested that the NPRM (79 FR 38799, 
July 9, 2014) be revised to add inspection and repair procedures for 
cracks in the MEC drip shield that do not appear in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-25A3640, dated 
January 8, 2014. UPS stated that the NPRM was issued to address drip 
shield cracks that were found incidentally during compliance with AD 
2011-16-06, Amendment 39-16764 (76 FR 47427, August 5, 2011), but in 
areas not specifically addressed by AD 2011-16-06. UPS stated that due 
to the potential existence of cracks undetected during the 
accomplishment of AD 2011-16-06, UPS believes that a specific 
inspection is warranted to find and correct such damage. UPS stated 
that an inspection of the area for drip shield cracks would mitigate 
potential safety risks, which may necessitate further regulatory 
action.
    We disagree with the commenter's request. Boeing and the FAA do not 
have evidence to suspect that other areas in the drip shield system are 
at risk; further, instructions are not available for additional 
locations to be inspected or procedures to repair detected cracks at 
those locations at this time. A visual inspection may not detect 
existing cracks in all areas of the drip shield, such as in the bonded 
seams.
    We find that the required installation adequately addresses the 
identified unsafe condition. Adding inspection and repair procedures 
would increase the overall work required, and would provide only a 
negligible benefit to safety. We have not changed this final rule in 
this regard.

Request To Revise the Compliance Time

    UPS requested that the compliance time be changed from 24 months to 
72 months for Model 747-400 BCF airplanes on which the corrective 
actions have been done as required by AD 2012-17-12, Amendment 39-17175 
(77 FR 54798, September 6, 2012), and AD 2011-16-06, Amendment 39-16764 
(76 FR 47427, August 5, 2011). UPS stated that it believes the drip 
shield to be a secondary moisture protection for the MEC on Model 747-
400 BCF airplanes due to the absence of steerable power drive units 
with drains above the drip shield in question. UPS stated that the 
safety risk of undetected cracking of the drip shield has been 
significantly mitigated due to the corrective actions required by ADs 
2012-17-12 and 2011-16-06.
    We disagree with the commenter's request. The drip shield is a 
primary barrier for moisture protection, designed to specifically 
prevent water from entering the MEC. While there may be other sources 
of water drainage in the Model 747-400 BCF configuration that may 
reduce the chance of water being channeled to the drip shield, there is 
still a likelihood of water reaching the MEC drip shield, and its 
failure exposes critical hardware directly to water damage.
    In addition, compliance with AD 2012-17-12, Amendment 39-17175 (77 
FR 54798, September 6, 2012), and AD 2011-16-06, Amendment 39-16764 (76 
FR 47427, August 5, 2011), would not help mitigate the unsafe condition 
identified in this final rule because, although the ADs are related, 
the specified corrective actions are applicable to different unsafe 
conditions in different locations. AD 2012-17-12 requires that affected 
operators modify and seal the floor panels from body stations 140 to 
640 to prevent water leakage between the panels. AD 2011-16-06 requires 
affected operators to install a fiberglass reinforcing overcoat on the 
drip shield in a location prone to cracks; that location is different 
from the location identified in this final rule.
    The risks of each unsafe condition identified in AD 2012-17-12, 
Amendment 39-17175 (77 FR 54798, September 6, 2012); AD 2011-16-06, 
Amendment 39-16764 (76 FR 47427, August 5, 2011); and this final rule; 
were evaluated separately. The unsafe

[[Page 27076]]

conditions and corresponding corrective actions are applicable to 
different groups of Model 747-400 airplanes, and although many are 
affected by more than one unsafe condition, all safety concerns 
identified were studied separately based on reports from multiple 
operators regarding multiple airplane configurations. Based on the 
frequency of reported failures, severity of outcome, and airplane 
usage, each study showed an unsafe condition if left uncorrected.
    Addressing only one source of water intrusion would neither 
preclude nor diminish the probability of the other sources of water 
intrusion adversely affecting continued safe flight. For these reasons, 
we have not changed this final rule in this regard.

Request To Clarify Required for Compliance Statement in the Service 
Information

    UPS requested clarification on the RC (required for compliance) 
statement found in paragraph (h)(4) of the NPRM (79 FR 38799, July 9, 
2014). UPS asked whether the RC statement applies to all components of 
a step and whether other alternative procedures can be used in lieu of 
the accepted alternative procedure identified in each substep or steps 
in the figures.
    We agree that clarification is necessary. Refer to FAA Advisory 
Circular (AC) No. 20-176A, dated June 16, 2014 (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/
979ddd1479e1ec6f86257cfc0052d4e9/$FILE/AC%2020-176A.PDF). If the 
accomplishment step in the service information is labeled RC and has 
substeps or tasks with no paragraph designation under the labeled RC 
step, then all of the substeps or tasks must also be completed. In 
addition, if the accomplishment step in the service information is 
marked RC and states to do the work ``in accordance with'' a figure, 
drawing, or illustration, then all of the information in the figure, 
drawing, or illustration is mandatory.
    If a step is marked RC and a procedure or document must be followed 
to accomplish a task in a service bulletin, the appropriate terminology 
to cite the procedure or document is ``in accordance with.'' However, 
if a step is marked RC and a procedure or document may be followed to 
accomplish an action (e.g., the design approval holder's procedure or 
document may be used, but an FAA-accepted procedure could also be 
used), the appropriate terminology to use to cite the procedure or 
document is ``refer to . . . as an accepted procedure.'' We have not 
changed this final rule in this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD as proposed, except for minor editorial changes. We have 
determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (79 FR 38799, July 9, 2014) for correcting the unsafe condition; 
and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (79 FR 38799, July 9, 2014).

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 747-25A3640, dated 
January 8, 2014. The service information describes procedures for 
installing a fiberglass reinforcing overcoat on the MEC drip shield. 
Refer to this service information for information on the procedures and 
compliance times. This service information is reasonably available; see 
ADDRESSES for ways to access this service information.

Costs of Compliance

    We estimate that this AD affects 15 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Installation of a fiberglass          36 work-hours x $85 per              $0           $3,060          $45,900
 reinforcing overcoat on the MEC       hour = $3,060.
 drip shield.
----------------------------------------------------------------------------------------------------------------

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.

[[Page 27077]]

Sec.  39.13  [Amended]


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

2015-09-05 The Boeing Company: Amendment 39-18151; Docket No. FAA-
2014-0429; Directorate Identifier 2014-NM-039-AD.

(a) Effective Date

    This AD is effective June 16, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400 and 747-400F 
airplanes, certificated in any category, as identified in Boeing 
Alert Service Bulletin 747-25A3640, dated January 8, 2014.

(d) Subject

    Air Transport Association (ATA) of America Code 25, Equipment/
Furnishings.

(e) Unsafe Condition

    This AD was prompted by reports of cracking in the main 
equipment center (MEC) drip shield and exhaust plenum. We are 
issuing this AD to prevent water penetration into the MEC, which 
could result in an electrical short and potential loss of several 
functions essential for safe flight.

(f) Compliance

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

(g) Installation

    Within 24 months after the effective date of this AD, install a 
fiberglass reinforcing overcoat on the MEC drip shield, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-25A3640, dated January 8, 2014.

(h) 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 (i) 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 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. For a repair method to be approved, the repair must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) If any service information contains steps that are 
identified as RC (Required for Compliance), those steps must be done 
to comply with this AD; any steps that are not labeled as RC are 
recommended. Those steps that are not labeled as RC may be deviated 
from using accepted methods in accordance with the operator's 
maintenance or inspection program without obtaining approval of an 
AMOC, provided the steps labeled as RC can be done and the airplane 
can be put back in a serviceable condition. Any substitutions or 
changes to steps labeled as RC require approval of an AMOC.

(i) Related Information

    For more information about this AD, contact Francis Smith, 
Aerospace Engineer, Cabin Safety and Environmental Systems Branch, 
ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue SW., Renton, WA 98057-3356; telephone: 425-917-6596; fax: 
425-917-6590; email: [email protected].

(j) 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 Alert Service Bulletin 747-25A3640, dated January 8, 
2014.
    (ii) Reserved.
    (3) For Boeing 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 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.
    (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 April 17, 2015.
Victor Wicklund,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-10069 Filed 5-11-15; 8:45 am]
 BILLING CODE 4910-13-P