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Federal Register / Vol. 86, No. 231 / Monday, December 6, 2021 / Rules and Regulations
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the proposed AD only identifies Boeing Alert Requirements Bulletin B787
81205SB53007500 RB, Issue 001, dated September 8, 2020; therefore, the FAA has changed paragraph c of this AD to identify both bulletins, as requested by the commenter.
Request To Remove Certain Thresholds AAL asked that the FAA remove the flight length sensitive FLS threshold requirements in paragraph g of the proposed AD. AAL stated that the Compliance paragraph specified in Boeing Alert Requirements Bulletins B78781205SB53007500 RB and B78781205SB53007600 RB, both Issue 001, both dated September 8, 2020, includes the formulas to calculate the FLS threshold, and these formulas are based on aircraft cycles and hours.
AAL added that its internal tracking process can only use flight-cycles, flight-hours, and days, its systems cannot use formulas to take full advantage of the FLS threshold. AAL
noted that the current compliance data would require the use of the most conservative values or constant monitoring of aircraft utilization. AAL
suggested that the FAA include simplified limits in this paragraph, allowing operators to maximize the hours and cycle threshold.
UAL also asked that the FAA remove the formula for the threshold requirements in paragraph g of the proposed AD. UAL suggested incorporating simplified flight-hour and flight-cycle limits that can be easily tracked in its existing system. UAL
added that its system is not able to accommodate the existing formula.
The FAA does not agree with the commenters request. FLS threshold requirements were developed with the flexibility to take advantage of individual aircraft utilization. An operator may choose to develop simplified thresholds, provided they are at or below the required compliance times. As stated in paragraph g of this AD, guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletins B78781205SB53007500 and B787
81205SB53007600, both Issue 001, dated both September 8, 2020.
Appendix A of these documents is particularly instructive regarding compliance times. The FAA has not changed this AD in this regard.
Request To Use Alternative Repair Method AVA asked that the FAA change the following language used in paragraph h2 of the proposed AD This AD
requires doing the repair using a method
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approved in accordance with the procedures specified in paragraph i of this AD. AVA stated that this means submitting a request for an alternative method of compliance AMOC is required in accordance with paragraph i3 of the proposed AD. AVA added that the proposed repair is based on the time delay required to obtain an AMOC
letter, which affects the operational return to service of the affected aircraft, and noted that a Form 81009 is already an approved document that certifies compliance with the airworthiness standard. AVA proposed that only an 81009 approval form be required for doing a repair after contacting Boeing.
The FAA does not agree with the commenters request. An FAA Form 81009, which is both a repair data approval and AMOC approval, may be issued by the Boeing Company Organization Designation Authorization ODA, provided it has been authorized by the Manager, Seattle ACO Branch, FAA, as required by paragraph i3 of this AD. Therefore, the FAA has not changed this AD in this regard.
Request To Use Later Revision of the Service Information AVA asked that the FAA include a paragraph in this AD that approves any further revision or issue of Boeing Alert Requirements Bulletins B78781205
SB53007500 RB and B78781205
SB53007600 RB, both Issue 001, both dated September 8, 2020, for compliance with this AD.
The FAA does not agree with the commenters request. The FAA may not in an AD refer to any document that does not yet exist. In general terms, the FAA is required by Office of the Federal Register OFR regulations for approval of materials incorporated by reference, as specified in 1 CFR 51.1f, to either publish the service document contents as part of the actual AD language; or submit the service document to the OFR
for approval as referenced material, in which case the FAA may only refer to such material in the text of an AD. The AD may refer to the service document only if the OFR approved it for incorporation by reference. See 1 CFR
part 51.
To allow operators to use later revisions of the referenced document issued after publication of the AD, either the FAA must revise the AD to reference specific later revisions, or operators must request approval to use later revisions as an alternative method of compliance with this AD under the provisions of paragraph i of this AD.

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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 Alert Requirements Bulletin B78781205
SB53007500 RB, Issue 001, dated September 8, 2020. The service information describes procedures for repetitive high frequency eddy current HFEC inspections for cracking around all the fasteners common to the front spar pickle fork outer chord surface between stringer S22 and stringer S24
at station STA 873 on the left and right sides, and along the entire forward edge of the front spar pickle fork outer chord covered by the body chord splice angle between stringer S24 and stringer S25
at STA 873 on the left and right sides, and repair of any cracking found. The service information also describes procedures for repetitive ultrasonic UT
inspections for cracking of the front spar pickle fork outer chord along the upper, lower and aft edges of the end fittings at stringer S23 at STA 873, on the left and right sides, and repair of any cracking found.
The FAA also reviewed Boeing Alert Requirements Bulletin B78781205
SB53007600 RB, Issue 001, dated September 8, 2020. The service information describes procedures for repetitive HFEC inspections for cracking along the entire forward edge of the front spar body chord in the area covered by the body chord splice angle at stringer S25 on the left and right sides, and the splice fitting at BL 0, STA
873, and repair of any cracking found.
The service information also describes procedures for repetitive detailed inspections of the front spar body chord horizontal flange surface between stringer S26 to stringer S40 at STA
873 on the left and right sides and repair of any cracking found. The service information also describes procedures for repetitive UT inspections for cracking of the of the front spar body chord horizontal flange along the upper and lower edges of the end fittings at stringer S27, at STA 873 on the left and right sides, and repair of any cracking found.
This service information is reasonably available because the interested parties
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