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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

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Final rule.

# 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                               ( print 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:                         *samuel.lee@faa.gov.*

# 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                           ( print 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.                

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                           ( print 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 × $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

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

      ( print page 4144)    Authority:49 U.S.C. 106(g), 40113, 44701.

§ 39.13

2. The FAA amends § 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),                                   ( print 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:                             *9-AWP-LAACO-ADS@faa.gov.*

(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:                             *samuel.lee@faa.gov.*

## (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,                             *fr.inspection@nara.gov,*                             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.

# Footnotes

1.                                                     *https://drs.faa.gov/​browse/​excelExternalWindow/​dba562e3-218f-423a-b24e-a1e77ded8e0a.*
        Back to Citation      

[FR Doc. 2022-01568 Filed 1-26-22; 8:45 am]

BILLING CODE 4910-13-P