[Federal Register Volume 87, Number 213 (Friday, November 4, 2022)]
[Proposed Rules]
[Pages 66615-66619]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-23901]



[[Page 66615]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1170; Project Identifier AD-2022-00023-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all The Boeing Company Model 747-400, -400D, and -400F series 
airplanes. This proposed AD was prompted by the FAA's analysis of the 
Model 747 airplane fuel system reviews conducted by the manufacturer, 
and by the determination that new or more restrictive airworthiness 
limitations are necessary. This proposed AD would require revising the 
existing maintenance or inspection program, as applicable, to 
incorporate new or more restrictive airworthiness limitations. The FAA 
is proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by December 
19, 2022.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to regulations.gov. Follow 
the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, 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 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 regulations.gov by searching for and 
locating Docket No. FAA-2022-1170.

Examining the AD Docket

    You may examine the AD docket at regulations.gov by searching for 
and locating Docket No. FAA-2022-1170; 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 NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Samuel Dorsey, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone: 206-231-3415; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2022-1170; Project Identifier 
AD-2022-00023-T'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to 
Samuel Dorsey, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-
3415; email: [email protected]. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking.

Background

    The FAA has examined the underlying safety issues involved in fuel 
tank explosions on several large transport airplanes, including the 
adequacy of existing regulations, the service history of airplanes 
subject to those regulations, and existing maintenance practices for 
fuel tank systems. As a result of those findings, the FAA issued a 
final rule titled ``Transport Airplane Fuel Tank System Design Review, 
Flammability Reduction and Maintenance and Inspection Requirements'' 
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards 
for transport airplanes and new maintenance requirements that rule 
included Amendment 21-78, which established Special Federal Aviation 
Regulation No. 88 (SFAR 88) at 14 CFR part 21. Subsequently, SFAR 88 
was amended by Amendment 21-82 (67 FR 57490, September 10, 2002; 
corrected at 67 FR 70809, November 26, 2002), Amendment 21-83 (67 FR 
72830, December 9, 2002; corrected at 68 FR 37735, June 25, 2003, to 
change ``21-82'' to ``21-83''), and Amendment 21-101 (83 FR 9162, March 
5, 2018).
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC)) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the final rule published on 
May 7, 2001, the FAA intended to adopt airworthiness directives to 
mandate any changes found necessary to address unsafe conditions 
identified as a result of these reviews.
    In evaluating these design reviews, the FAA has established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that

[[Page 66616]]

require corrective actions. The percentage of operating time during 
which fuel tanks are exposed to flammable conditions is one of these 
criteria. The other three criteria address the failure types under 
evaluation: single failures, single failures in combination with 
another latent condition(s), and in-service failure experience. For all 
four criteria, the evaluations included consideration of previous 
actions taken that may mitigate the need for further action.
    This proposed AD was prompted by significant changes made to the 
airworthiness limitations (AWLs) related to fuel tank ignition 
prevention and the nitrogen generation system. This condition, if not 
addressed, could result in the potential for ignition sources inside 
fuel tanks caused by latent failures, alterations, repairs, or 
maintenance actions, which, in combination with flammable fuel vapors, 
could result in fuel tank explosions and consequent loss of the 
airplane.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related ADs

    The FAA issued AD 2008-10-06 R1, Amendment 39-16160 (75 FR 906, 
January 7, 2010), which applies to certain Model 747-400, -400D, and -
400F series airplanes. AD 2008-10-06 R1 requires revising the existing 
maintenance program by incorporating new airworthiness limitations 
(AWLs) for fuel tank systems to satisfy SFAR 88 requirements. That AD 
also requires the phasing in of certain repetitive AWL inspections, and 
repair if necessary. AD 2008-10-06 R1 was prompted by the FAA's 
analysis of the fuel system reviews of Model 747 airplanes conducted by 
the manufacturer.
    This proposed AD also affects the following ADs, which include 
requirements to incorporate certain airworthiness limitations into the 
existing maintenance or inspection program. Revising the existing 
maintenance or inspection program specified in this proposed AD would 
terminate certain actions specified in these ADs:
     AD 2008-18-09, Amendment 39-15666 (73 FR 52911, September 
12, 2008), which applies to certain Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes.
     AD 2010-13-12, Amendment 39-16343 (75 FR 37997, July 1, 
2010), which applies to certain Model 747-100, 747-100B, 747-100B SUD, 
747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 
747SR, and 747SP series airplanes.
     AD 2010-14-08, Amendment 39-16353 (75 FR 38397, July 2, 
2010), which applies to certain Model 747-400, -400D, and -400F series 
airplanes.
     AD 2011-06-03, Amendment 39-16627 (76 FR 15814, March 22, 
2011), which applies to certain Model 747-100, 747-100B, 747-100B SUD, 
747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 
747SR, and 747SP series airplanes.
     AD 2014-15-14, Amendment 39-17916 (79 FR 45324, August 5, 
2014), which applies to certain Model 747-100, 747-100B, 747-100B SUD, 
747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 
747SR, and 747SP series airplanes.
     AD 2016-19-03, Amendment 39-18652 (81 FR 65872, September 
26, 2016), which applies to certain Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), of Boeing 747-400 
Maintenance Planning Data (MPD) Document, D621U400-9, dated September 
2021. This service information specifies airworthiness limitations for 
fuel tank systems. 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.

Proposed AD Requirements in This NPRM

    This proposed AD would require revising the existing maintenance or 
inspection program, as applicable, to incorporate new or more 
restrictive airworthiness limitations. For information on the 
procedures and compliance times, see this service information at 
regulations.gov by searching for and locating Docket No. FAA-2022-1170.
    This proposed AD would require revisions to certain operator 
maintenance documents to include new actions (e.g., inspections) and 
Critical Design Configuration Control Limitations (CDCCLs). Compliance 
with these actions and CDCCLs is required by 14 CFR 91.403(c). For 
airplanes that have been previously modified, altered, or repaired in 
the areas addressed by this proposed AD, the operator may not be able 
to accomplish the actions described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must request 
approval for an alternative method of compliance according to paragraph 
(k) of this proposed AD.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 119 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed 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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and

[[Page 66617]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

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

The Proposed Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

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


Sec.  39.13  [Amended]

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

The Boeing Company: Docket No. FAA-2022-1170; Project Identifier AD-
2022-00023-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by December 19, 2022.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) through 
(7) of this AD.
    (1) AD 2008-10-06 R1, Amendment 39-16160 (75 FR 906, January 7, 
2010) (AD 2008-10-06 R1).
    (2) AD 2008-18-09, Amendment 39-15666 (73 FR 52911, September 
12, 2008) (AD 2008-18-09).
    (3) AD 2010-13-12, Amendment 39-16343 (75 FR 37997, July 1, 
2010) (AD 2010-13-12).
    (4) AD 2010-14-08, Amendment 39-16353 (75 FR 38397, July 2, 
2010) (AD 2010-14-08).
    (5) AD 2011-06-03, Amendment 39-16627 (76 FR 15814, March 22, 
2011) (AD 2011-06-03).
    (6) AD 2014-15-14, Amendment 39-17916 (79 FR 45324, August 5, 
2014) (AD 2014-15-14).
    (7) AD 2016-19-03, Amendment 39-18652 (81 FR 65872, September 
26, 2016) (AD 2016-19-03).

(c) Applicability

    This AD applies to all The Boeing Company Model 747-400, -400D, 
and -400F 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 the FAA's analysis of the fuel system 
reviews on Model 747-400, -400D, and -400F series airplanes 
conducted by the manufacturer, and by the determination that new or 
more restrictive airworthiness limitations are necessary. The FAA is 
issuing this AD to reduce the potential of ignition sources inside 
fuel tanks, which, in combination with flammable fuel vapors, could 
result in fuel tank explosions and consequent loss 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 specified in Section B, Airworthiness 
Limitations--Systems, of Section 9, Airworthiness Limitations (AWLs) 
and Certification Maintenance Requirements (CMRs), of Boeing 747-400 
Maintenance Planning Data (MPD) Document, D621U400-9, dated 
September 2021; except as provided by paragraph (h) of this AD. The 
initial compliance time for doing the airworthiness limitation 
instruction (ALI) tasks is at the times specified in paragraphs 
(g)(1) through (13) of this AD.
    (1) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': At the applicable time specified in paragraph (g)(1)(i) or 
(ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-01 in their maintenance or inspection program before the 
effective date of this AD: Within 144 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 12 months after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(1)(i) of this 
AD: Within 144 months since AWL No. 28-AWL-01 was added to the 
maintenance or inspection program, or within 144 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
01, whichever occurs later.
    (2) For AWL No. 28-AWL-03, ``Fuel Quantity Indication System 
(FQIS)--Out of Tank Wiring Lightning Shield to Ground Termination'': 
At the applicable time specified in paragraph (g)(2)(i) or (ii) of 
this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-03 in their maintenance or inspection program before the 
effective date of this AD: Within 144 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 12 months after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(2)(i) of this 
AD: Within 144 months since AWL No. 28-AWL-03 was added to the 
maintenance or inspection program, or within 144 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
03, whichever occurs later.
    (3) For AWL No. 28-AWL-10, ``Main Tank, Center Wing Tank, and 
Horizontal Stabilizer Tank (if installed) Refuel Valve 
Installation--Fault Current Bond'': At the applicable time specified 
in paragraph (g)(3)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-10 in their maintenance or inspection program before the 
effective date of this AD: Within 144 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 12 months after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(3)(i) of this 
AD: Within 144 months since AWL No. 28-AWL-10 was added to the 
maintenance or inspection program, or within 144 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
10, whichever occurs later.
    (4) For AWL No. 28-AWL-17, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Fault Current Detector (FCD) 
for Center Wing Tank (CWT) Pumps and Inboard Main Tank Override/
Jettison (O/J) Pumps and Horizontal Stabilizer Tank (HST) Transfer 
Fuel Pumps'': At the applicable time specified in paragraph 
(g)(4)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-17 in their maintenance or inspection program before the 
effective date of this AD: Within 18 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(4)(i) of this 
AD: Within 18 months since AWL No. 28-AWL-17 was added to the 
maintenance or inspection program, or within 18 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
17, whichever occurs later.
    (5) For AWL No. 28-AWL-24, ``Horizontal Stabilizer Tank (HST) 
Fuel Pump Automatic Shutoff Circuit (If Installed)'': At the 
applicable time specified in paragraph (g)(5)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-24 in their maintenance or inspection program before the 
effective date of this AD: Within 12 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(5)(i) of this 
AD: Within 12 months since AWL No. 28-AWL-24 was added to the 
maintenance or inspection program, or within 12 months after the 
most

[[Page 66618]]

recent inspection was performed as specified in AWL No. 28-AWL-24, 
whichever occurs later.
    (6) For AWL No. 28-AWL-26, ``Main Tank 2 and Main Tank 3 
Override/Jettison Fuel Pump Uncommanded on System'': At the 
applicable time specified in paragraph (g)(6)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-26 in their maintenance or inspection program before the 
effective date of this AD: Within 12 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(6)(i) of this 
AD: Within 12 months since AWL No. 28-AWL-26 was added to the 
maintenance or inspection program, or within 12 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
26, whichever occurs later.
    (7) For AWL No. 28-AWL-28, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Main Tank AC Fuel Pump Ground 
Fault Interrupter (GFI)'': At the applicable time specified in 
paragraph (g)(7)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-28 in their maintenance or inspection program before the 
effective date of this AD: Within 12 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(7)(i) of this 
AD: Within 12 months since AWL No. 28-AWL-28 was added to the 
maintenance or inspection program, or within 12 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
28, whichever occurs later.
    (8) For AWL No. 28-AWL-29, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Center Tank Scavenge AC Fuel 
Pump Ground Fault Interrupter (GFI)'': At the applicable time 
specified in paragraph (g)(8)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-29 in their maintenance or inspection program before the 
effective date of this AD: Within 12 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(8)(i) of this 
AD: Within 12 months since AWL No. 28-AWL-29 was added to the 
maintenance or inspection program, or within 12 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
29, whichever occurs later.
    (9) For AWL No. 28-AWL-33, ``Cushion Clamps and Teflon Sleeving 
Installed on Out-of-Tank Wire Bundles Installed on Brackets that are 
Mounted Directly on the Fuel Tanks,'' at the applicable time 
specified in paragraph (g)(9)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-33 in their maintenance or inspection program before the 
effective date of this AD: Within 144 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 12 months after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(9)(i) of this 
AD: Within 144 months since AWL No. 28-AWL-33 was added to the 
maintenance or inspection program, or within 144 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
33, whichever occurs later.
    (10) For AWL No. 28-AWL-40, ``Reserve Tank Refuel Valve 
Installation--Lightning Protection Electrical Bond,'' at the 
applicable time specified in paragraph (g)(10)(i) or (ii) of this 
AD.
    (i) For airplanes that did not have any version of AWL No. 28-
AWL-40 in their maintenance or inspection program before the 
effective date of this AD: Within 72 months since issuance of the 
original airworthiness certificate or original export certificate of 
airworthiness, or within 12 months after the effective date of this 
AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(10)(i) of 
this AD: Within 72 months since AWL No. 28-AWL-40 was added to the 
maintenance or inspection program, or within 72 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
40, whichever occurs later.
    (11) For AWL No. 47-AWL-07, ``Nitrogen Generation System--
Nitrogen Enriched Air (NEA) Distribution Ducting Inspection,'' at 
the applicable time specified in paragraph (g)(11)(i) or (ii) of 
this AD.
    (i) For airplanes that did not have any version of AWL No. 47-
AWL-07 in their maintenance or inspection program before the 
effective date of this AD: Within 21,250 total flight hours since 
issuance of the original airworthiness certificate or original 
export certificate of airworthiness, or within 4 months after the 
effective date of this AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(11)(i) of 
this AD: Within 21,250 total flight hours since AWL No. 47-AWL-07 
was added to the maintenance or inspection program, or within 21,250 
total flight hours after the most recent inspection was performed as 
specified in AWL No. 47-AWL-07, whichever occurs later.
    (12) For AWL No. 47-AWL-08, ``Nitrogen Generation System [NGS]--
Cross-Vent Check Valve Functional Check,'' at the applicable time 
specified in paragraph (g)(12)(i) or (ii) of this AD.
    (i) For airplanes that did not have any version of AWL No. 47-
AWL-08 in their maintenance or inspection program before the 
effective date of this AD: Within 21,250 total flight hours since 
issuance of the original airworthiness certificate or original 
export certificate of airworthiness, or within 4 months after the 
effective date of this AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(12)(i) of 
this AD: Within 21,250 total flight hours since AWL No. 47-AWL-08 
was added to the maintenance or inspection program, or within 21,250 
total flight hours after the most recent inspection was performed as 
specified in AWL No. 47-AWL-08, whichever occurs later.
    (13) For AWL No. 47-AWL-10, ``NGS--Thermal Switch,'' at the 
applicable time specified in paragraph (g)(13)(i) or (ii) of this 
AD.
    (i) For airplanes that did not have any version of AWL No. 47-
AWL-10 in their maintenance or inspection program before the 
effective date of this AD: Within 54,000 total flight hours since 
issuance of the original airworthiness certificate or original 
export certificate of airworthiness, or within 4 months after the 
effective date of this AD, whichever occurs later.
    (ii) For airplanes not identified in paragraph (g)(13)(i) of 
this AD: Within 54,000 total flight hours since AWL No. 47-AWL-10 
was added to the maintenance or inspection program, or within 54,000 
total flight hours after the most recent inspection was performed as 
specified in AWL No. 47-AWL-10, whichever occurs later.

(h) Additional Acceptable Wire Types and Sleeving

    As an option, 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-08 identifies wire types BMS 13-48, BMS 
13-58, and BMS 13-60, the following wire types, as applicable, 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.
    (2) Where AWL No. 28-AWL-08 identifies TFE-2X Standard wall for 
wire sleeving, the following sleeving materials are acceptable: 
Roundit 2000NX and Varglas Type HO, HP, or HM, as applicable.

(i) 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 (k) of this AD.

(j) Terminating Actions

    (1) Accomplishing the actions required by paragraph (g) of this 
AD terminates all requirements of AD 2008-10-06 R1.
    (2) Accomplishing the actions required by paragraph (g) of this 
AD terminates paragraph

[[Page 66619]]

(g)(2) of AD 2008-18-09 for Model 747-400, -400D, and -400F 
airplanes only.
    (3) Accomplishing the actions required by paragraph (g) of this 
AD terminates paragraph (h)(1) of AD 2010-13-12 for Model 747-400, -
400D, and -400F airplanes only.
    (4) Accomplishing the actions required by this AD terminates 
paragraph (j) of AD 2010-14-08.
    (5) Accomplishing the actions required by paragraph (g) of this 
AD terminates paragraph (l) of AD 2011-06-03 for Model 747-400, -
400D, and -400F airplanes only.
    (6) Accomplishing the actions required by paragraph (g) of this 
AD terminates paragraph (h)(1) of AD 2014-15-14 for Model 747-400, -
400D, and -400F airplanes only.
    (7) Accomplishing the actions required by paragraph (g) of this 
AD terminates paragraph (h) of AD 2016-19-03 for Model 747-400, -
400D, and -400F airplanes only.

(k) 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 (l)(1) 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.

(l) Related Information

    (1) For more information about this AD, contact Samuel Dorsey, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3415; 
email: [email protected].
    (2) 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 myboeingfleet.com. You may 
view this referenced 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.

    Issued on September 19, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-23901 Filed 11-3-22; 8:45 am]
BILLING CODE 4910-13-P


