Airworthiness Directives; The Boeing Company Airplanes

[Federal Register Volume 91, Number 189 (Thursday, October 1, 2026)]
[Rules and Regulations]
[Pages 62299-62301]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-20120]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-2730; Project Identifier AD-2025-01579-T; 
Amendment 39-23477; AD 2026-20-04]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
The Boeing Company Model 757-300 series airplanes. This AD was prompted 
by a crack growth analysis that indicated that existing maintenance 
planning data (MPD) and supplemental structural inspection program 
(SSIP) tasks do not provide adequate inspection opportunities to detect 
cracks in the upper frames around the uppermost fastener common to the 
fail-safe chord at the fuselage frame splices. This AD requires an 
inspection or maintenance record check for existing repairs, repetitive 
inspections of the upper frames around the uppermost fastener common to 
the fail-safe chord at the fuselage frame splices for any cracks, and 
applicable on-condition actions. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective November 5, 2026.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 5, 
2026.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2026-2730; 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.
    Material Incorporated by Reference:
    <bullet> For Boeing material 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; website myboeingfleet.com.
    <bullet> You may view this material 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 under 
Docket No. FAA-2026-2730.

FOR FURTHER INFORMATION CONTACT: Wayne Ha, Aviation Safety Engineer, 
FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5238; 
email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all The Boeing Company 
Model 757-300 series airplanes. The NPRM was published in the Federal 
Register on April 2, 2026 (91 FR 16593). The NPRM was prompted by a 
report that crack growth analysis indicated that existing MPD and SSIP 
tasks do not provide adequate inspection opportunities to detect cracks 
in the upper frames around the uppermost fastener common to the fail-
safe chord at the fuselage frame splices between stringers S-13 to S-
14, from station (STA) 1380 to STA 1620. In the NPRM, the FAA proposed 
to require an inspection or maintenance record check for existing 
repairs, repetitive inspections of the upper frames around the 
uppermost fastener common to the fail-safe chord at the fuselage frame 
splices for any cracks, and applicable on-condition actions. The FAA is 
issuing this AD to address cracking in the upper frames around the 
uppermost fastener common to the fail-safe chord at certain fuselage 
frame splices, which could lead to multiple upper frame failures. The 
unsafe condition, if not addressed, could result in the inability of a 
principal structural element to sustain limit loads and the loss of 
continued safe flight and landing.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from Boeing who supported the NPRM 
without change.
    The FAA received additional comments from Aviation Partners Boeing 
(APB) and United Airlines (United). 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

    APB stated that accomplishing Supplemental Type Certificate (STC) 
ST01518SE does not affect the actions specified in the proposed AD. APB 
stated that Boeing has delegation from APB to review and approve data 
in areas affected by STC ST01518SE for the blended winglet 
configuration. The provisions of paragraph (i)(2) in the proposed AD 
remain applicable to The Boeing Company Model 757-300 series airplanes 
modified by STC ST01518SE, with blended winglets or production wingtips 
installed.
    The FAA concurs with the commenter. The FAA has redesignated 
paragraph (c) of the proposed AD as paragraph (c)(1) of this AD and 
added paragraph (c)(2) to this AD to state that installation of STC 
ST01518SE does not affect the ability to accomplish the actions 
required by this AD. Therefore,

[[Page 62300]]

for airplanes on which STC ST01518SE is installed, a ``change in 
product'' alternative method of compliance (AMOC) approval request is 
not necessary to comply with the requirements of 14 CFR 39.17.

Request To Correct Typographical Error in Service Material

    United requested that the FAA revise Table 2 of Boeing Alert 
Requirements Bulletin 757-53A0122 RB, dated September 26, 2025, to 
correct the references to stringers S-13L and S-14L in certain steps. 
United stated that Table 2 applies to the right side in both the 
compliance and actions required for compliance sections and, therefore, 
the stringer references should be S-13R and S-14R.
    The FAA agrees that Table 2 of Boeing Alert Requirements Bulletin 
757-53A0122 RB, dated September 26, 2025, contains typographical errors 
in certain stringer references. The FAA has added an exception in 
paragraph (h)(3) of this AD to correct the typographical errors.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. 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.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 757-53A0122 RB, 
dated September 26, 2025. This material specifies procedures for 
performing a general visual inspection or a maintenance records check 
of the forward and aft sides of the upper frames at the frame splices 
between S-13 and S-14 on the left and right sides, from STA 1380 to STA 
1620, for any repair and applicable on-condition actions. On-condition 
actions include contacting Boeing for alternative inspection and 
corrective action instructions and doing the alternative inspection and 
applicable corrective actions in the repaired areas.
    This material also specifies procedures for repetitive detailed 
inspections of the upper frames around the uppermost fastener common to 
the fail-safe chord at the frame splices between S-13 and S-14 on the 
left and right sides, from STA 1380 to STA 1620, for any crack and 
applicable on-condition actions. On-condition actions include 
contacting Boeing for repair instructions and doing the repair.
    This material is reasonably available because the interested 
parties have access to it through their normal course of business or by 
the means identified in the ADDRESSES section.

Costs of Compliance

    The FAA estimates that this AD affects 37 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
              Action                     Labor cost       Parts cost    Cost per product          operators
----------------------------------------------------------------------------------------------------------------
General visual inspection or        Up to 70 work-hours           $0  Up to $5,950........  Up to $220,150.
 maintenance records check.          x $85 per hour =
                                     $5,950.
Detailed inspection...............  4 work-hours x $85             0  $340 per inspection   $12,580 per
                                     per hour = $340 per               cycle.                inspection cycle.
                                     inspection cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the alternative inspections and on-condition actions 
specified in this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

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

The Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

    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:

2026-20-04 The Boeing Company: Amendment 39-23477; Docket No. FAA-
2026-2730; Project Identifier AD-2025-01579-T.

(a) Effective Date

    This airworthiness directive (AD) is effective November 5, 2026.

(b) Affected ADs

    None.

[[Page 62301]]

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 757-300 
series airplanes, certificated in any category.
    (2) Installation of Supplemental Type Certificate (STC) 
ST01518SE does not affect the ability to accomplish the actions 
required by this AD. Therefore, for airplanes on which STC ST01518SE 
is installed, a ``change in product'' alternative method of 
compliance (AMOC) approval request is not necessary to comply with 
the requirements of 14 CFR 39.17.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by a crack growth analysis that indicated 
that the existing maintenance planning data and supplemental 
structural inspection program tasks do not provide adequate 
inspection opportunities to detect cracks in the upper frames around 
the uppermost fastener common to the fail-safe chord at certain 
fuselage frame splices. The FAA is issuing this AD to address 
cracking in the upper frames around the uppermost fastener common to 
the fail-safe chord at certain fuselage frame splices, which could 
lead to multiple upper frame failures. The unsafe condition, if not 
addressed, could result in the inability of a principal structural 
element to sustain limit loads and the loss of continued safe flight 
and landing.

(f) Compliance

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

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 757-53A0122 RB, dated September 26, 
2025, do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 757-53A0122 RB, dated September 26, 2025.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
757-53A0122, dated September 26, 2025, which is referred to in 
Boeing Alert Requirements Bulletin 757-53A0122 RB, dated September 
26, 2025.

(h) Exceptions to Requirements Bulletin Specifications

    (1) Where the Compliance Time column of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 757-
53A0122 RB, dated September 26, 2025, refers to the original issue 
date of Requirements Bulletin 757-53A0122 RB, this AD requires using 
the effective date of this AD.
    (2) Where Boeing Alert Requirements Bulletin 757-53A0122 RB, 
dated September 26, 2025, specifies contacting Boeing for repair 
instructions or for alternative inspections: This AD requires doing 
the repair, or doing the alternative inspections and applicable on-
condition actions, using a method approved in accordance with the 
procedures specified in paragraph (i) of this AD.
    (3) Where Table 2 in the ``Compliance'' paragraph and the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
757-53A0122 RB, dated September 26, 2025, states ``S-13L and S-
14L'', for this AD replace that text with ``S-13R and S-14R''.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, AIR-520, Continued Operational Safety 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 Continued Operational 
Safety Branch, send it to the attention of the person identified in 
paragraph (j)(1) of this AD. Information may be emailed to: 
[email protected]. Before using any approved AMOC, notify your 
appropriate principal inspector, or lacking a principal inspector, 
the manager of the responsible Flight Standards Office.
    (2) 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, AIR-
520, Continued Operational Safety 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.

(j) Additional Information

    (1) For more information about this AD, contact Wayne Ha, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 562-627-5238; email: [email protected].
    (2) Material identified in this AD that is not incorporated by 
reference is available at the address specified in paragraph (k)(3) 
of this AD.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 757-53A0122 RB, dated 
September 26, 2025.
    (ii) [Reserved]
    (3) For Boeing material 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; website myboeingfleet.com.
    (4) You may view this material 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 material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on September 22, 2026.
Brian Knaup,
Acting Deputy Director, Integrated Certificate Management Division, 
Aircraft Certification Service.
[FR Doc. 2026-20120 Filed 9-30-26; 8:45 am]
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