[Federal Register Volume 87, Number 18 (Thursday, January 27, 2022)]
[Rules and Regulations]
[Pages 4140-4145]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-01568]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0331; Project Identifier AD-2020-01703-T; 
Amendment 39-21887; AD 2021-26-28]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
The Boeing Company Model 757 airplanes. This AD was prompted by 
significant changes, including new or more restrictive requirements, 
made to the

[[Page 4141]]

airworthiness limitations (AWLs) related to fuel tank ignition 
prevention and the nitrogen generation system. This AD requires 
revising the existing maintenance or inspection program, as applicable, 
to incorporate new or more restrictive airworthiness limitations. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective March 3, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 3, 
2022.

ADDRESSES: For service information identified in this final rule, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. You may view this service information at the 
FAA, Airworthiness Products Section, Operational Safety Branch, 2200 
South 216th St., Des Moines, WA. For information on the availability of 
this material at the FAA, call 206-231-3195. It is also available at 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-0331.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0331; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this final rule, any 
comments received, and other information. The address for Docket 
Operations is 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: Samuel Lee, Aerospace Engineer, 
Propulsion Section, FAA, Los Angeles ACO Branch, 3960 Paramount Blvd., 
Lakewood, CA 90712-4102; phone: 562-627-5262; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all The Boeing Company 
Model 757 airplanes. The NPRM published in the Federal Register on May 
10, 2021 (86 FR 24786). The NPRM was prompted by significant changes, 
including new or more restrictive requirements, made to the AWLs 
related to fuel tank ignition prevention and the nitrogen generation 
system. In the NPRM, the FAA proposed to require revising the existing 
maintenance or inspection program, as applicable, to incorporate new or 
more restrictive airworthiness limitations. The FAA is issuing this AD 
to address ignition sources inside the fuel tanks and the increased 
flammability exposure of the center fuel tank caused by latent 
failures, alterations, repairs, or maintenance actions, which could 
result in a fuel tank explosion and consequent loss of an airplane.

Revised Service Information Since the NPRM Was Issued

    Since the NPRM was issued, the FAA has reviewed Boeing 757 
Maintenance Planning Data (MPD) Document, Section 9, Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D622N001-9, dated September 2020. The revised service information adds 
a section that references any Boeing service bulletin modifications 
that include supplemental structural inspections. This service 
information revision does not affect the technical content of this AD. 
The FAA has revised this final rule to require the September 2020 
version of the service information.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from The Air Line Pilots Association, 
International (ALPA), Boeing, and United Airlines who supported the 
NPRM without change.
    The FAA received additional comments from three commenters, 
including Aviation Partners Boeing (APB), Delta Airlines (DAL), and VT 
Mobile Aerospace Engineering (VT MAE), Inc. The following presents the 
comments received on the NPRM and the FAA's response to each comment.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that the installation of winglets 
per Supplemental Type Certificate (STC) STC ST01518SE does not affect 
the accomplishment of the manufacturer's service instructions.
    The FAA agrees with the commenter that STC ST01518SE does not 
affect the accomplishment of the manufacturer's service instructions. 
Therefore, the installation of STC ST01518SE does not affect the 
ability to accomplish the actions required by this AD. The FAA has not 
changed this AD in this regard.

Request To Use Certain Documents Associated With a Certain STC

    VT MAE proposed that certain maintenance planning documents 
associated with VT MAE STCs be included in the NPRM. VT MAE stated that 
certain maintenance documents associated with VT MAE STCs supersede AWL 
No. 28-AWL-01 of Boeing 757 Maintenance Planning Data (MPD) Document, 
Section 9, Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D622N001-9, dated March 2020.
    The FAA disagrees with the commenter's request. A maintenance 
document associated with an STC cannot replace an AWL task established 
by the type design holder of the aircraft. Furthermore, the maintenance 
documents referred to by VT MAE and associated with VT MAE STCs are 
unrelated to the unsafe condition addressed by this AD. If any safety 
issue associated with VT MAE STCs is reported to the FAA, the FAA may 
consider a separate AD action to mandate necessary information. The FAA 
has not changed this AD in this regard.

Request To Clarify Compliance for a Certain STC

    DAL requested clarification on how an operator would comply with 
AWL No. 28-AWL-19 for airplanes that have incorporated TDG Aerospace 
STC ST01950LA, which installs the universal fault interrupter (UFI) in 
place of the Boeing ground fault interrupter (GFI) that is referenced 
in AWL No. 28-AWL-19.
    The FAA provides the following clarification. AWL No. 28-AWL-19 
specifies the actions that are required before the fuel pump circuit 
breakers or the GFIs are reset. If the TDG Aerospace UFI is installed 
in place of the GFI, the actions associated with the GFI as specified 
in AWL No. 28-AWL-19 are no longer applicable, but the actions 
associated with the fuel pump circuit breakers in AWL No. 28-AWL-19 are 
still applicable. The FAA has not changed this AD in this regard.

Request To Clarify the Revision Level for Certain Service Information

    DAL requested clarification of the Boeing service bulletins 
associated with certain AWLs specified by the proposed AD. DAL stated 
that the Boeing service bulletins are identified without a revision 
level in the applicability column for the AWLs and that the revision 
level should be identified. DAL commented that clarification of the

[[Page 4142]]

revision level would ensure that operators have the correct information 
for each AWL.
    The FAA disagrees with the request. The FAA has previously issued 
ADs for Model 757 airplanes requiring accomplishment of the service 
bulletins referenced in the AWLs associated with Air Transport 
Association (ATA) Chapter 28. Those ADs specify the revision level of 
the required service bulletins. If the revision level of a service 
bulletin is specified in an AWL, it may be possible to have a situation 
where the revision levels of the service bulletin specified in an AWL 
and an AD are inconsistent. This could occur when an AD has a provision 
to allow accomplishment of an earlier revision level of the service 
bulletin within a certain time period, or when an AD is superseded to 
mandate a later revision of a service bulletin that was previously 
required. Such a situation would cause confusion and possibly require a 
change to an AWL and issuance of a new AD to require an updated AWL. 
Therefore, the FAA has determined that it would be more effective to 
not specify the revision level of the referenced service bulletins in 
the AWLs, so that any conflict regarding the revision level of a 
service bulletin would not occur between an AWL and an AD that mandated 
the service bulletin.
    As for the AWLs associated with ATA Chapter 47, the operating 
rules, such as 14 CFR 121.1117(d), 125.509(d) and 129.117(d), require 
operators to install an FAA-approved flammability reduction means 
(Boeing Nitrogen Generation System (NGS)). In addition, the operating 
rules, such as 14 CFR 121.1117(g), 125.509(g), and 129.117(g), require 
operators to revise the maintenance or inspection program to include 
applicable airworthiness limitations. The AWLs associated with ATA 
Chapter 47 and the service bulletins referenced in these AWLs were 
developed when these operating rules were promulgated. The service 
bulletins and the AWLs for NGS were approved for compliance with 
applicable 14 CFR part 25 regulations during certification of the 
Boeing NGS. Since development of the Boeing NGS service bulletins, the 
FAA has not received any reports that would raise concern for 
accomplishing a specific revision level of a service bulletin 
associated with those operating rules. The FAA has not changed this 
final rule in this regard.

Request To Not Mandate a Certain AWL in the Proposed AD

    DAL requested that incorporation of AWL No. 47-AWL-06 in Boeing 757 
Maintenance Planning Data (MPD) Document, Section 9, Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D622N001-9, dated March 2020, not be required in the proposed AD until 
specific service instructions are identified and compliance times are 
adequately defined. DAL stated that certain language in AWL No. 47-AWL-
06 requires either that operators implement these FAA-approved design 
changes or that operators implement other design changes or operational 
procedural changes approved by the FAA Oversight Office within the 
compliance time stated in the service instructions. DAL commented that 
this language essentially forces operators to show compliance for a 
document that does not yet exist.
    DAL also commented that if Boeing publishes service instructions 
that are FAA approved, then the CDCCL in its current state strips the 
operator's ability to comment on the service instructions before the 
service instructions become law.
    The FAA disagrees with the request to not mandate the incorporation 
of AWL No. 47-AWL-06. This specific CDCCL was determined to be 
necessary during the certification of the NGS as discussed in FAA 
Equivalent Level of Safety Finding for the Fuel Tank Flammability Rule 
(FTFR) on Boeing Company Models 737 Classic, 737NG, 747-400, 747-8, 
757, 767, 777 and 787 Series Airplanes, Memo No. PS05-0177-P-2, dated 
November 20, 2015 (ELOS memorandum).\1\ The fuel tank flammability 
analysis conducted by Boeing for the NGS certification was based on 
airplane descent rates that were slower than the rates defined in 
Reduction of Fuel Tank Flammability in Transport Category Airplanes (73 
FR 42444, July 21, 2008), the FTFR rule. The data provided by Boeing 
showed that when the airplane descent rate defined in the rule was 
used, the flammability levels would exceed the limits required by the 
FTFR rule. Boeing proposed to use descent rates slower than the rates 
defined in the FTFR rule and provided supportive data based on 
operation of the transport fleet. Under the ELOS memorandum, Boeing is 
required to monitor U.S. fleet descent rates and to develop service 
instructions if the fleet average flammability exposure approaches the 
limits required by the FTFR rule due to an increase in the descent 
rates. These requirements for Boeing and the conditions specified in 
the CDCCL, which include the requirement for operators to incorporate 
service instructions, were determined to be compensating design 
features or alternative standards to justify the ELOS finding.
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    \1\ https://drs.faa.gov/browse/excelExternalWindow/dba562e3-218f-423a-b24e-a1e77ded8e0a.
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    Furthermore, incorporation of the AWLs associated with ATA Chapter 
47 required for Model 757 airplanes is required by operating rules such 
as 14 CFR 121.1117(g), 125.509(g), and 129.117(g). Therefore, an 
earlier version of AWL No. 47-AWL-06 with essentially the same content 
as the version of AWL No. 47-AWL-06 that is mandated by this AD should 
already exist in operator's maintenance or inspection program, as 
applicable. This AD requires incorporation of AWL No. 47-AWL-06 in 
Boeing 757 Maintenance Planning Data (MPD) Document, Section 9, 
Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), D622N001-9, dated September 2020. Even if the 
requirement to incorporate AWL No. 47-AWL-06 is removed from this AD as 
proposed by the commenter, operators still must comply with the same 
requirements of AWL No. 47-AWL-06 that already exist in their 
maintenance or inspection program, as applicable. The FAA has not 
changed this final rule in this regard.

Request for Clarification for Incorporating Section E of the Service 
Information

    DAL requested clarification of the requirements for paragraph (g) 
of the proposed AD. DAL stated that paragraph (g) of the proposed AD 
would require incorporating the information in Section E, including 
Subsections E.1 and E.3, of Boeing 757 Maintenance Planning Data (MPD) 
Document, Section 9, Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D622N001-9, dated March 2020. DAL 
stated that Section E contains subsections E.1, E.2, E.3, and E.4, so 
it is unclear why Subsections E.1 and E.3 are specifically identified, 
because it seems redundant. DAL commented that if only Subsections E.1 
and E.3 are required, then those subsections should be identified 
specifically.
    The FAA provides the following clarification. Section E contains 
information prior to the beginning of Subsection E.1, such as 
``Introduction'' and ``Regulatory Agency Approval.'' The FAA has 
determined that certain information, such as the information provided 
under the ``Definitions,'' is critical to performing the maintenance 
required by the AWLs. Paragraph (g) of this AD requires incorporation 
of the information contained in Section E prior to the beginning of 
Subsection E.1, as

[[Page 4143]]

well as incorporation of Subsections E.1 and E.3. Incorporation of the 
information in Subsections E.2 and E.4 was previously addressed by 
separate AD actions or as an alternative methods of compliance (AMOC). 
Since then, the information in Subsections E.2 and E.4 has not been 
revised to a level that would affect safety and warrant a new AD 
action. Therefore, the FAA has clarified paragraph (g) of this AD to 
specify that incorporation of Subsections E.2 and E.4 into the existing 
maintenance or inspection program, as applicable, is not required by 
this AD.

Request To Remove Certain Service Information From the AWL

    DAL requested removal of Boeing Service Bulletin 757-47-0005, as 
specified in the ``Applicability'' column of certain AWLs in Boeing 757 
Maintenance Planning Data (MPD) Document, Section 9, Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D622N001-9, dated March 2020, and in paragraphs (g)(10) through (12) of 
the proposed AD. DAL stated the service information is not available to 
operators, and removal of the service information in the AWLs would 
help operators better understand the scope of the proposed AD.
    The FAA disagrees with the commenter's request since Boeing Service 
Bulletin 757-47-0005 applies only to certain operators. The FAA has 
confirmed with Boeing that Service Bulletin 757-47-0005 can be searched 
and accessed only by operators who are affected by that service 
information. The FAA has not changed this final rule in this regard.

Request To Use a Previously Issued AMOC

    Aviation Partners Boeing stated it has an existing AMOC that 
corresponds to AD 2012-12-15, Amendment 39-17095 (77 FR 42964, July 23, 
2012) (AD 2012-12-15), which allows Model 757-300 series airplanes with 
STC ST01518SE to install a longer fastener than what is specified in 
Item 4 of AWL No. 28-AWL-18 in Boeing 757 Maintenance Planning Data 
(MPD) Document, Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D622N001-9, dated March 
2020. APB suggested that paragraph (k) of the proposed AD include AMOCs 
approved for AD 2012-12-15 for the corresponding actions in paragraphs 
(j)(1) and (2) of the proposed AD.
    The FAA agrees that the AMOC for AD 2012-12-15, which was approved 
for STC ST01518SE, should be addressed. The FAA previously determined 
that the installation of an alternative fastener under STC ST01518SE 
would be adequate. However, the FAA has determined that it would be 
more appropriate to specify the requirements associated with STC 
ST01518SE in this AD instead of accepting a previously approved AMOC. 
The FAA has added paragraph (i) in this AD to address airplanes that 
have been modified under STC ST01518SE. In addition, subsequent 
paragraphs in this AD have been redesignated accordingly.

Additional Changes to the AMOC Paragraph

    Since the NPRM was issued, the FAA has updated paragraph (l) of 
this AD to specify the Los Angeles ACO Branch has the authority to 
approve AMOCs for this AD.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Except for minor editorial changes, and any other changes 
described previously, this AD is adopted as proposed in the NPRM. None 
of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing 757 Maintenance Planning Data (MPD) 
Document, Section 9, Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D622N001-9, dated September 2020. This 
service information specifies airworthiness limitation instruction 
(ALI) and CDCCL tasks related to fuel tank ignition prevention and the 
nitrogen generation system. 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 
ADDRESSES.

Costs of Compliance

    The FAA estimates that this AD affects 493 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:
    The FAA has determined that revising the existing maintenance or 
inspection program takes an average of 90 work-hours per operator, 
although the agency recognizes that this number may vary from operator 
to operator. Since operators incorporate maintenance or inspection 
program changes for their affected fleet(s), the FAA has determined 
that a per-operator estimate is more accurate than a per-airplane 
estimate. Therefore, the FAA estimates the average total cost per 
operator to be $7,650 (90 work-hours x $85 per work-hour).

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.
    The FAA is 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) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

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

The 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:


[[Page 4144]]


    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:

2021-26-28 The Boeing Company: Amendment 39-21887; Docket No. FAA-
2021-0331; Project Identifier AD-2020-01703-T.

(a) Effective Date

    This airworthiness directive (AD) is effective March 3, 2022.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) and (2) 
of this AD.
    (1) AD 2012-12-15, Amendment 39-17095 (77 FR 42964, July 23, 
2012) (AD 2012-12-15).
    (2) AD 2018-20-13, Amendment 39-19447 (83 FR 52305, October 17, 
2018) (AD 2018-20-13).

(c) Applicability

    This AD applies to all The Boeing Company Model 757-200, -200PF, 
-200CB, and -300 series airplanes, certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by significant changes, including new or 
more restrictive requirements, made to the airworthiness limitations 
(AWLs) related to fuel tank ignition prevention and the nitrogen 
generation system. The FAA is issuing this AD to address ignition 
sources inside the fuel tanks and the increased flammability 
exposure of the center fuel tank caused by latent failures, 
alterations, repairs, or maintenance actions, which could result in 
a fuel tank explosion and consequent loss of an airplane.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

    Except as provided by paragraphs (h) and (i) of this AD, within 
60 days after the effective date of this AD, revise the existing 
maintenance or inspection program, as applicable, to incorporate the 
information specified in Section E., ``Airworthiness Limitations--
Systems,'' of the Boeing 757 Maintenance Planning Data (MPD) 
Document, Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D622N001-9, dated 
September 2020; except this AD does not require incorporation of the 
information specified in Subsections E.2 and E.4. The initial 
compliance time for doing the airworthiness limitation instruction 
(ALI) tasks is at the times specified in paragraphs (g)(1) through 
(12) of this AD.
    (1) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': Within 120 months after the most recent inspection was 
performed as specified in AWL No. 28-AWL-01.
    (2) For AWL No. 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out Tank Wiring Lightning Shield to Ground Termination'': 
Within 120 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-03.
    (3) For AWL No. 28-AWL-14, ``Main and Center Wing Tank Fueling 
Shutoff Valve Body and Actuator--Fault Current Bond'': Within 120 
months after the most recent inspection was performed as specified 
in AWL No. 28-AWL-14.
    (4) For AWL No. 28-AWL-20, ``Center Tank Fuel Override Boost 
Pump Automatic Shutoff System'': Within 12 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
757-28A0081 or Boeing Service Bulletin 757-28A0082, as applicable; 
or within 12 months after the most recent inspection was performed 
as specified in AWL No. 28-AWL-20; whichever occurs later.
    (5) For AWL No. 28-AWL-21, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Boost Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after accomplishment of the 
actions specified in Boeing Service Bulletin 757-28A0078 or Boeing 
Service Bulletin 757-28A0079, as applicable; or within 12 months 
after the most recent inspection was performed as specified in AWL 
No. 28-AWL-21; whichever occurs later.
    (6) For AWL No. 28-AWL-25, ``Motor Operated Valve (MOV) 
Actuator--Lightning and Fault Current Protection Electrical Bond'': 
Within 72 months after accomplishment of the actions specified in 
Boeing Service Bulletin 757-28A0088, or within 72 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
25, whichever occurs later.
    (7) For AWL No. 28-AWL-26, ``Center Tank Fuel Boost Pump Power 
Failed On Protection System'': Within 12 months after accomplishment 
of the actions specified in Boeing Service Bulletin 757-28A0105, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-26, whichever occurs later.
    (8) For AWL No. 28-AWL-30, ``AC Fuel Pump Fault Current Bonding 
Jumper Installation, Main and Center Tank'': Within 24 months after 
the effective date of this AD, or within 72 months after the most 
recent inspection was performed as specified in AWL No. 28-AWL-30, 
whichever occurs later.
    (9) For AWL No. 28-AWL-33, ``Full Cushion Clamps and Teflon 
Sleeving Installed on Out-of-Tank Wire Bundles Installed on Brackets 
that are Mounted Directly on the Fuel Tanks'': Within 24 months 
after the effective date of this AD; or within 144 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
757-57A0064 (Part 2 through Part 10 of the Work Instructions); or 
within 144 months since the most recent inspection was performed as 
specified in AWL No. 28-AWL-33; whichever occurs later.
    (10) For AWL No. 47-AWL-04, ``NGS--NEA Distribution Ducting'': 
Within 17,300 flight hours after accomplishment of the actions 
specified in Boeing Service Bulletin 757-47-0001 or Boeing Service 
Bulletin 757-47-0005, as applicable; or within 17,300 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-04; whichever occurs later.
    (11) For AWL No. 47-AWL-05, ``NGS--Cross Vent Check Valve'': 
Within 17,300 flight hours after accomplishment of the actions 
specified in Boeing Service Bulletin 757-47-0001 or Boeing Service 
Bulletin 757-47-0005, as applicable; or within 17,300 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-05; whichever occurs later.
    (12) For AWL No. 47-AWL-07, ``NGS--Thermal Switch'': Within 
48,000 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 757-47-0001 or Boeing Service Bulletin 757-
47-0005, as applicable; or within 48,000 flight hours after the most 
recent inspection was performed as specified in AWL No. 47-AWL-07; 
whichever occurs later.

(h) Additional Acceptable Wire Types and Sleeving

    During accomplishment of the actions required by paragraph (g) 
of this AD, the alternative materials specified in paragraphs (h)(1) 
and (2) of this AD are acceptable.
    (1) Where AWL No. 28-AWL-05 identifies wire types BMS 13-48, BMS 
13-58, and BMS 13-60, the following wire types are acceptable: MIL-
W-22759/16, SAE AS22759/16 (M22759/16), MIL-W-22759/32, SAE AS22759/
32 (M22759/32), MIL-W-22759/34, SAE AS22759/34 (M22759/34), MIL-W-
22759/41, SAE AS22759/41 (M22759/41), MIL-W-22759/86, SAE AS22759/86 
(M22759/86), MIL-W-22759/87, SAE AS22759/87 (M22759/87), MIL-W-
22759/92, and SAE AS22759/92 (M22759/92); and MIL-C-27500 and NEMA 
WC 27500 cables constructed from these military or SAE specification 
wire types, as applicable.
    (2) Where AWL No. 28-AWL-05 identifies TFE-2X Standard wall for 
wire sleeving, the following sleeving materials are acceptable: 
Roundit 2000NX and Varglas Type HO, HP, or HM.

(i) Additional Acceptable Materials for Airplanes Modified Under 
Aviation Partners Boeing Supplemental Type Certificate (STC) ST01518SE

    During accomplishment of the actions required by paragraph (g) 
of this AD, the following alternative materials are acceptable: For 
Model 757-300 series airplanes modified using Aviation Partners 
Boeing STC ST01518SE, issued March 25, 2005, where AWL No. 28-AWL-18 
requires the use of conductive fasteners having Part Number (P/N) 
BACB30LR4-7, this AD allows the use of conductive fasteners having 
P/N BACB30LR4-7 and P/N BACB30LR4-9.

(j) No Alternative Actions, Intervals, or CDCCLs

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections),

[[Page 4145]]

intervals, or CDCCLs may be used unless the actions, intervals, and 
CDCCLs are approved as an alternative method of compliance (AMOC) in 
accordance with the procedures specified in paragraph (l) of this 
AD.

(k) Terminating Actions for Certain AD Requirements

    Accomplishment of the revision required by paragraph (g) of this 
AD terminates the requirements specified in paragraphs (k)(1) and 
(2) of this AD for that airplane.
    (1) All requirements of AD 2012-12-15.
    (2) The requirements in paragraph (i)(2) of AD 2018-20-13.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles ACO Branch, 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 responsible Flight Standards 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in Related Information. 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 responsible Flight Standards 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 Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Los 
Angeles ACO Branch, FAA, 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.

(m) Related Information

    For more information about this AD, contact Samuel Lee, 
Aerospace Engineer, Propulsion Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Blvd., Lakewood, CA 90712-4102; phone: 562-627-5262; 
email: [email protected].

(n) 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 757 Maintenance Planning Data (MPD) Document, Section 
9, Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), D622N001-9, dated September 2020.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; internet https://www.myboeingfleet.com.
    (4) You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 2200 
South 216th St., Des Moines, WA. For information on the availability 
of this material at the FAA, call 206-231-3195.
    (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, [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on December 17, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-01568 Filed 1-26-22; 8:45 am]
BILLING CODE 4910-13-P