[Federal Register Volume 86, Number 246 (Tuesday, December 28, 2021)]
[Rules and Regulations]
[Pages 73660-73664]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-28133]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0134; Project Identifier AD-2020-01254-T; 
Amendment 39-21833; AD 2021-24-12]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 777 airplanes. This AD was prompted by 
significant changes, including new or more restrictive requirements, 
made to the airworthiness limitations (AWLs) and Critical Design 
Configuration Control Limitations (CDCCLs) related to fuel tank 
ignition prevention, the engine fuel suction feed system, 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 February 1, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of February 1, 
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-2021-0134.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0134; 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

[[Page 73661]]

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: Kevin Nguyen, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3555; 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 certain The Boeing 
Company Model 777 airplanes. The NPRM published in the Federal Register 
on March 26, 2021 (86 FR 16133). The NPRM was prompted by significant 
changes, including new or more restrictive requirements, made to the 
AWLs and CDCCLs related to fuel tank ignition prevention, the engine 
fuel suction feed system, 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; and 
to address potential loss of engine fuel suction feed capability, which 
could result in dual engine flameouts, inability to restart engines, 
and consequent forced landing of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from The Air Line Pilots Association, 
International (ALPA), and FedEx Express, who supported the NPRM without 
change.
    The FAA received additional comments from three commenters, 
including American Airlines (AAL), Boeing, and United Airlines (UAL). 
The following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Delay Issuance of the NPRM

    Boeing requested delay of issuance of the NPRM until updated 
service information is available. Boeing stated that the service 
information has been updated to Section 9, Airworthiness Limitations 
(AWLs) and Certification Maintenance Requirements (CMRs), D622W001-9, 
dated February 2021, of Boeing 777-200/200LR/300/300ER/777F Maintenance 
Planning Data (MPD) Document, which modified two AWLs that are not 
currently mandated by AD 2008-11-13, Amendment 39-15536 (73 FR 30737, 
May 29, 2008) (AD 2008-11-13) (which will be terminated by this AD), 
and that the AWLs have changed significantly. Boeing commented that 
using the latest service information eliminates the need for approval 
of an alternative method of compliance (AMOC) for the revised AWLs.
    Boeing also stated that the delay of the NPRM should occur after 
Section 9, Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D622W001-9, dated February 2021, of 
Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data (MPD) 
Document, has been migrated to an ``SCI [special compliance items]/AWL 
document D622W001-9-04.'' Boeing commented that FAA approval and 
publication of this document to MyBoeingFleet is anticipated by October 
2021. Boeing also commented that the migration of the document will 
make the method of compliance more manageable for the FAA, Boeing, and 
the operators, and that it will also eliminate the need for an AMOC to 
use the ``SCI/AWL document.'' Boeing asked that paragraph (g) of the 
proposed AD be revised to the document name and revision date of the 
new ``SCI/AWL document'' when approved by the FAA.
    The FAA partially agrees with the commenter's request. The FAA 
agrees to allow operators the option to use Section 9, Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D622W001-9, dated February 2021, of Boeing 777-200/200LR/300/300ER/777F 
Maintenance Planning Data (MPD) Document, for the reasons provided 
above. The February 2021 revision of Section 9 has significant updates 
to AWL 28-AWL-31 and AWL 28-AWL-32 that were included in the November 
2019 revision of Section 9 to clarify the applicability of certain wire 
harnesses and wire bundles, and certain locations of Teflon sleeving 
and wire bundles. Either the November 2019 or February 2021 revision of 
Section 9 provides an adequate level of safety. The FAA has revised the 
``Related Service Information under 1 CFR part 51'' section of this 
final rule and paragraph (g) of this AD accordingly.
    In addition, the FAA has revised paragraph (h) of this AD to 
clarify certain description headers for 28-AWL-31 and 28-AWL-32 of 
Section D, ``Airworthiness Limitations--Systems,'' including 
Subsections D.1, D.2, and D.3, of Section 9, Airworthiness Limitations 
(AWLs) and Certification Maintenance Requirements (CMRs), D622W001-9, 
dated February 2021, of Boeing 777 200/200LR/300/300ER/777F Maintenance 
Planning Data (MPD) Document. The FAA has redesigned subsequent 
paragraphs accordingly.
    Since the SCI/AWL document has not yet been issued, the FAA 
disagrees to delay this final rule any further to wait for document 
migration. To delay this AD would be inappropriate since the FAA has 
determined that an unsafe condition exists and that the actions in this 
AD must be done to ensure continued safety. However, if an operator is 
unable to accomplish the actions in this AD for whatever reason, it may 
request approval of an AMOC under the provisions of paragraph (l)(1) of 
this AD. The FAA has not changed this final rule in this regard.

Request for an Exemption for Airplanes in Long-Term Storage

    UAL recommended that airplanes in long-term storage be exempt from 
the applicable initial compliance times in the proposed AD. UAL also 
recommended that the airworthiness limitation instructions (ALI) tasks 
in the proposed AD be accomplished at the applicable initial compliance 
times after the airplane is returned to service. UAL stated that 
paragraph (g) of the proposed AD requires the initial compliance time 
for doing the ALI tasks at the times specified in paragraphs (g)(1) 
through (10) of the proposed AD. UAL also stated that paragraphs (g)(1) 
through (5) of the proposed AD provides the flight cycles or days in 
which to do the ALI tasks after the most recent inspection, and 
paragraph (g)(6) of the proposed AD requires doing the ALI task within 
60 months after the effective date of this AD. UAL commented that due 
to varying circumstances, however, many of the affected airplanes are 
now in long-term storage.
    The FAA disagrees with UAL's recommendation to provide an exemption 
for airplanes in long-term storage. While the FAA understands that some 
airplanes are currently in long-term storage due to varying 
circumstances, it has determined that due to the unsafe condition, the 
initial compliance times for doing the ALI tasks represent an adequate 
amount of time to accomplish the actions required in this AD. If an 
operator is unable to

[[Page 73662]]

accomplish the actions in this AD for whatever reason, it may request 
for an approval of an AMOC under the provisions of paragraph (l)(1) of 
this AD. The FAA has not changed this AD in this regard.

Request To Remove Unqualified Wire Types

    Boeing requested removal of unqualified wire and wire sleeving 
types from the list of acceptable wire and wire sleeving types 
specified in paragraphs (h)(1) and (2) of the proposed AD. Boeing 
stated that it has qualified and certified wire types BMS 13-48, BMS 
13-58 and BMS 13-60, and Teflon wire sleeving TFE-2X, and it has not 
certified the additional wire and wire sleeving types for Boeing 
airplanes specified in paragraphs (h)(1) and (2) of the proposed AD.
    The FAA disagrees with the commenter's request. Due to the FAA's 
assessment of the critical design features, it has determined that 
additional non-Boeing alternative wire types, wire sleeves, and wire 
sleeving material, as specified in paragraphs (i)(1) and (2) of this 
AD, are acceptable. Since the issuance of AD 2008-11-13 (which is 
terminated by this AD), the FAA has received requests for approval of 
AMOCs from operators and supplemental type certificate (STC) holders 
(or applicants) to allow the installation of alternative wire types, 
wire sleeves, and wire sleeving materials. The FAA evaluated certain 
attributes of those alternative materials for each installation, and 
issued AMOC approvals for AD 2008-11-13 based on its determination that 
the installation of those wire types, wire sleeves, and wire sleeving 
materials would provide an acceptable level of safety. The FAA has not 
changed the AD in this regard.

Request for Clarification of Previously Issued AMOCs

    AAL requested clarification of previously issued AMOCs. AAL stated 
that for AD 2008-11-13, it currently uses AMOC 784-17-1576 with AWL 28-
AWL-AVDEC and AWL 28-AWL-16, for the installation of STC ST02532LA. AAL 
commented that the NPRM specifically stated that credit would not be 
granted for AMOCs previously approved under AD 2008-11-13, to which 
AMOC 784-17-1576 is applicable.
    AAL also commented that the NPRM specifically references operator's 
incorporating alternative versions of AWL 28-AWL-11, and that the FAA 
determined that certain critical design features specified in the AMOC-
approved versions are not acceptable to meet the intent of AWL 28-AWL-
11. AAL stated that the paragraph reads as though all AMOCs associated 
with AD 2008-11-13 are no longer approved; however, AAL uses AMOC 784-
17-1576 to install a series of gaskets that do not require a greasing 
component, while AWL 28-AWL-11 is associated with requirements for new 
wiring that penetrates the fuel tank wall.
    AAL commented that AMOC 784-17-1576 does not affect AWL 28-AWL-11 
or its fundamental elements, and that AMOC 784-17-1576 aligns with the 
incorporation of AWL 28-AWL-01 through AWL 28-AWL-20, inclusive of 
Section 9, Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D622W001-9, dated November 2019, of 
Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data (MPD) 
Document.
    The FAA provides the following clarification that was included in 
the NPRM for AMOCs previously approved for AD 2008-11-13. The FAA 
previously issued AMOC approvals for compliance with paragraph (g)(2) 
of AD 2008-11-13 to allow operators to incorporate alternative versions 
of AWL 28-AWL-11. For those STCs, the FAA approved alternative versions 
of AWL 28-AWL-11 that specified critical design features associated 
with STC modifications. The FAA has determined that certain critical 
design features specified in the AMOC-approved versions of AWL 28-AWL-
11 are no longer acceptable in meeting the intent of this AWL. 
Therefore, this AD does not allow credit for any AMOCs previously 
approved under AD 2008-11-13; AMOCs approved under AD 2008-11-13 will 
need to be resubmitted for evaluation. If an operator is unable to 
accomplish the actions in this AD for whatever reason, it may request 
an approval of an AMOC under the provisions of paragraph (l)(1) of this 
AD. The FAA has not changed this AD in this regard.

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 has reviewed the following service information.
     Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D622W001-9, dated 
November 2019, of Boeing 777-200/200LR/300/300ER/777F Maintenance 
Planning Data (MPD) Document.
     Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D622W001-9, dated 
February 2021, of Boeing 777-200/200LR/300/300ER/777F Maintenance 
Planning Data (MPD) Document.
    This service information describes airworthiness limitations and 
CDCCLs tasks related to fuel tank ignition prevention, the engine fuel 
suction feed system, and the nitrogen generation system. These 
documents are distinct because the February 2021 revision of Section 9 
includes updated information. 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 219 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

[[Page 73663]]

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:

    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:

2021-24-12 The Boeing Company: Amendment 39-21833; Docket No. FAA-
2021-0134; Project Identifier AD-2020-01254-T.

(a) Effective Date

    This airworthiness directive (AD) is effective February 1, 2022.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) and (2) 
of this AD.
    (1) AD 2008-11-13, Amendment 39-15536 (73 FR 30737, May 29, 
2008) (AD 2008-11-13).
    (2) AD 2014-09-09, Amendment 39-17844 (79 FR 30005, May 27, 
2014) (AD 2014-09-09).

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any 
category, having line numbers (L/Ns) 1 through 1609 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel; 47, 
Inert Gas System.

(e) Unsafe Condition

    This AD was prompted by significant changes, including new or 
more restrictive requirements, made to the airworthiness limitations 
(AWLs) and Critical Design Configuration Control Limitations 
(CDCCLs) related to fuel tank ignition prevention, the engine fuel 
suction feed system, 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; and to address potential loss of engine fuel 
suction feed capability, which could result in dual engine 
flameouts, inability to restart engines, and consequent forced 
landing of the airplane.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

    Within 60 days after the effective date of this AD, revise the 
existing maintenance or inspection program, as applicable, to 
incorporate the information in Section D, ``Airworthiness 
Limitations--Systems,'' including Subsections D.1, D.2, and D.3, of 
Section 9, Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D622W001-9, dated November 2019, of 
Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data (MPD) 
Document; or Section D, ``Airworthiness Limitations--Systems,'' 
including Subsections D.1, D.2, and D.3, of Section 9, Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements 
(CMRs), D622W001-9, dated February 2021, of Boeing 777-200/200LR/
300/300ER/777F Maintenance Planning Data (MPD) Document; except as 
provided by paragraph (h) and (i) of this AD. The initial compliance 
time for doing the airworthiness limitation instructions (ALI) tasks 
is at the times specified in paragraphs (g)(1) through (10) of this 
AD.
    (1) For AWL 28-AWL-01, ``External Wires Over Center Fuel Tank'': 
Within 16,000 flight cycles or 3,000 days, whichever occurs first 
after the date of issuance of the original airworthiness certificate 
or the date of issuance of the original export certificate of 
airworthiness; or within 16,000 flight cycles or 3,000 days, 
whichever occurs first after the most recent inspection was 
performed as specified in AWL 28-AWL-01; whichever occurs later.
    (2) For AWL 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out of Tank Wiring Lightning Shield to Ground Termination'': 
Within 16,000 flight cycles or 3,000 days, whichever occurs first 
after the date of issuance of the original airworthiness certificate 
or the date of issuance of the original export certificate of 
airworthiness; or within 16,000 flight cycles or 3,000 days, 
whichever occurs first after the most recent inspection was 
performed as specified in AWL 28-AWL-03; whichever occurs later.
    (3) For AWL 28-AWL-18, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--AC Fuel Pump GFI and GFP'': 
Within 375 days after the date of issuance of the original 
airworthiness certificate or the date of issuance of the original 
export certificate of airworthiness; or within 375 days after 
accomplishment of the actions specified in Boeing Service Bulletin 
777-28A0037; or within 375 days after accomplishment of the actions 
specified in Boeing Service Bulletin 777-28A0038; or within 375 days 
after the most recent inspection was performed as specified in AWL 
28-AWL-18; whichever occurs latest.
    (4) For AWL 28-AWL-21, ``External Wires Over Auxiliary Fuel Tank 
(Cell)'': Within 16,000 flight cycles or 3,000 days, whichever 
occurs first after the date of issuance of the original 
airworthiness certificate or date of issuance of the original export 
certificate of airworthiness; or within 16,000 flight cycles or 
3,000 days, whichever occurs first after the most recent inspection 
was performed as specified in AWL 28-AWL-21; or within 365 days 
after the effective date of this AD; whichever occurs latest.
    (5) For AWL 28-AWL-26, ``Auxiliary Fuel Tank (Cell) AC Fuel Pump 
Uncommanded ON/Automatic Shutoff Circuit'': Within 375 days after 
the date of issuance of the original airworthiness certificate or 
the date of issuance of the original export certificate of 
airworthiness; or within 375 days after the most recent inspection 
was performed as specified in AWL 28-AWL-26; or within 30 days after 
the effective date of this AD; whichever occurs latest.
    (6) For AWL 28-AWL-32, ``Cushion Clamps and Teflon Sleeving 
Installed on Out-of-Tank Wire Bundles Installed on Brackets that are 
Mounted Directly on the Fuel Tanks'': For airplanes having L/Ns 1 
through 503 inclusive, within 3,750 days after accomplishment of the 
actions specified in Boeing Service Bulletins 777-57A0050, or within 
60 months after the effective date of this AD, whichever occurs 
later. For airplanes having L/Ns 504 and subsequent, within 3,750 
days after the date of issuance of the original airworthiness 
certificate or the date of issuance of the original export 
certificate of airworthiness; or within 60 months after the 
effective date of this AD; whichever occurs later.
    (7) For AWL 28-AWL-101, ``Engine Fuel Suction Feed Operational 
Test'': Within 7,500 flight hours after the date of issuance of the 
original airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness; or within 7,500 flight 
hours after the most recent inspection was performed as specified in 
AWL 28-AWL-101; whichever occurs later.
    (8) For AWL 47-AWL-04, ``NGS--Thermal Switch'': Within 108,000 
flight hours after the date of issuance of the original 
airworthiness certificate or the date of issuance of the original 
export certificate of

[[Page 73664]]

airworthiness; or within 108,000 flight hours after accomplishment 
of the actions specified in Boeing Service Bulletin 777-47-0002; or 
within 108,000 flight hours after the most recent inspection was 
performed as specified in AWL 47-AWL-04; whichever occurs latest.
    (9) For AWL 47-AWL-05, ``NGS--Cross Vent Check Valve'': Within 
10,682 flight hours after the date of issuance of the original 
airworthiness certificate or the date of issuance of the original 
export certificate of airworthiness; or within 10,682 flight hours 
after accomplishment of the actions specified in Boeing Service 
Bulletin 777-47-0002; or within 10,682 flight hours after the most 
recent inspection was performed as specified in AWL 47-AWL-05; 
whichever occurs latest.
    (10) For AWL 47-AWL-06, ``NGS--NEA Distribution Ducting 
Integrity'': Within 10,682 flight hours after the date of issuance 
of the original airworthiness certificate or the date of issuance of 
the original export certificate of airworthiness; or within 10,682 
flight hours after accomplishment of the actions specified in Boeing 
Service Bulletin 777-47-0002; or within 10,682 flight hours after 
the most recent inspection was performed as specified in AWL 47-AWL-
06; whichever occurs latest.

(h) Exceptions to February 2021 Revision of Section 9

    The following exceptions apply to 28-AWL-31 and 28-AWL-32 of 
Section D, ``Airworthiness Limitations--Systems,'' including 
Subsections D.1, D.2, and D.3, of Section 9, Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements 
(CMRs), D622W001-9, dated February 2021, of Boeing 777-200/200LR/
300/300ER/777F Maintenance Planning Data (MPD) Document.
    (1) In paragraph 1.i., change ``Front Spar Bulkhead (Center 
Tank)'' to ``Front Spar Bulkhead (Center Wing Tank Fuel Quantity 
Greater than 12,400 Gallons).''
    (2) In paragraph 1.j., change ``Rear Spar Bulkhead (Center 
Tank)'' to ``Rear Spar Bulkhead (Center Wing Tank Fuel Quantity 
Greater than 12,400 Gallons).''

(i) Additional Acceptable Wire Types and Sleeving

    As an option, when accomplishing the actions required by 
paragraph (g) of this AD, the changes specified in paragraphs (i)(1) 
and (2) of this AD are acceptable.
    (1) Where AWL 28-AWL-11 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 28-AWL-11 identifies TFE-2X Standard wall 
(manufactured as specified in MIL-I-23053) for wire sleeving, the 
following sleeving materials are acceptable: Roundit 2000NX and 
Varglas Type HO, HP, or HM.

(j) No Alternative Actions, Intervals, or Critical Design Configuration 
Control Limitations (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), 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

    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 2008-11-13 for Model 777-200, -200LR, 
-300, and -300ER series airplanes only.
    (2) All requirements of AD 2014-09-09.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle 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 paragraph (m) 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 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, Seattle 
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 Kevin Nguyen, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3555; 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) Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D622W001-9, dated 
November 2019, of Boeing 777-200/200LR/300/300ER/777F Maintenance 
Planning Data (MPD) Document.
    (ii) Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D622W001-9, dated 
February 2021, of Boeing 777-200/200LR/300/300ER/777F Maintenance 
Planning Data (MPD) Document.
    (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 November 16, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-28133 Filed 12-27-21; 8:45 am]
BILLING CODE 4910-13-P


