[Federal Register Volume 91, Number 37 (Wednesday, February 25, 2026)]
[Proposed Rules]
[Pages 9205-9207]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-03782]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-1339; Project Identifier AD-2025-01162-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 certain The Boeing Company Model 777-200, -200LR, -300, -300ER, and
777F series airplanes. This proposed AD was prompted by reports of
cracks found on the main landing gear (MLG) support beam lower
stabilizer brace aft fitting lower flange attachment holes. This
proposed AD would require repetitive inspections of the MLG support
beam lower stabilizer brace aft fittings for any crack; repetitive
inspections of the MLG support beams and lower stabilizer braces for
any damage; repetitive inspections of the MLG support beams and the
upper and lower flanges of the MLG support beam lower stabilizer brace
aft fittings for any crack, or repetitive inspections of the upper and
lower flange surfaces of the MLG support beam lower stabilizer brace
aft fittings for any crack; and applicable on-condition corrective
actions. 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 April 13,
2026.
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.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2026-1339; 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.
Material Incorporated by Reference:
For Boeing material identified in this proposed 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.
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-2026-1339.
FOR FURTHER INFORMATION CONTACT: Camille Seay, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 817-
222-5149; 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 using a method listed
under the ADDRESSES section. Include ``Docket No. FAA-2026-1339;
Project Identifier AD-2025-01162-T'' at the beginning of your comments.
The most helpful comments reference a specific portion of the proposal,
explain the
[[Page 9206]]
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
Camille Seay, Aviation Safety Engineer, FAA, 2200 South 216th St., Des
Moines, WA 98198; phone: 817-222-5149; email: [email protected].
Any commentary that the FAA receives that is not specifically
designated as CBI will be placed in the public docket for this
rulemaking.
Background
The FAA has received reports indicating that cracks were found on
the MLG support beam lower stabilizer brace aft fitting lower flange
attachment holes on five airplanes. Analysis has shown that the MLG
support beam lower stabilizer brace aft fittings cracked due to
fatigue. If a cracked MLG support beam lower stabilizer brace aft
fitting was to break and sever from the lower stabilizer brace, the MLG
could collapse. A collapsed MLG during takeoff, landing, or ground
operations, if not addressed, could result in loss of control of the
airplane or result in a possible breach of a fuel tank. A breached fuel
tank could lead to a possible ignition source in the fuel tank and
consequent fire or explosion.
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.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 777-57A0128 RB,
dated June 2, 2025. This material specifies procedures for repetitive
detailed inspections of the left and right MLG support beam lower
stabilizer brace aft fittings for any crack, and repetitive detailed
inspections of the left and right MLG support beams and lower
stabilizer braces for any damage. This material also specifies
procedures for doing either (1) repetitive open hole high frequency
eddy current (HFEC) inspections of the upper and lower flanges of the
left and right MLG support beam lower stabilizer brace aft fittings and
MLG support beams for any crack; or (2) repetitive ultrasonic
inspections of the upper and lower flange surfaces of the left and
right MLG support beam lower stabilizer brace aft fittings for any
crack. This material also specifies doing on-condition actions, which
include replacing any cracked MLG support beam lower stabilizer brace
aft fitting and accomplishing post-replacement repetitive inspections;
and obtaining and following repair instructions for any cracked or
damaged MLG support beam and any damaged lower stabilizer brace.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the material already described, except for any differences
identified as exceptions in the regulatory text of this proposed AD.
For information on the procedures and compliance times, see this
material at regulations.gov under Docket No. FAA-2026-1339.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 311 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs
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Action Labor cost Parts cost Cost per product Cost on U.S. operators
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Repetitive inspections.. 35 work-hours x $85 per $0 $2,975 per inspection $925,225 per inspection
hour = $2,975 per cycle. cycle.
inspection cycle.
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The FAA estimates the following costs to do any necessary
replacement that would be required based on the results of the proposed
inspection. The agency has no way of determining the number of aircraft
that might need these replacements:
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Replacement of one MLG support beam lower 41 work-hour x $85 per hour = $13,580 $17,065
stabilizer brace aft fitting. $3,485.
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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
[[Page 9207]]
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 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-2026-1339; Project Identifier AD-
2025-01162-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by April 13, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any
category, as identified in Boeing Alert Requirements Bulletin 777-
57A0128 RB, dated June 2, 2025.
(d) Subject
Air Transport Association (ATA) of America Code 32, Landing
Gear.
(e) Unsafe Condition
This AD was prompted by reports of cracks found on the main
landing gear (MLG) support beam lower stabilizer brace aft fitting
lower flange attachment holes. The FAA is issuing this AD to address
a cracked MLG support beam lower stabilizer brace aft fitting, which
could lead to collapse of the MLG during takeoff, landing, or ground
operations. The unsafe condition, if not addressed, could result in
loss of control of the airplane or result in a possible breach of a
fuel tank. A breached fuel tank could lead to a possible ignition
source in the fuel tank and consequent fire or explosion.
(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 777-57A0128 RB, dated June 2, 2025, do
all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
777-57A0128 RB, dated June 2, 2025.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
777-57A0128, dated June 2, 2025, which is referred to in Boeing
Alert Requirements Bulletin 777-57A0128 RB, dated June 2, 2025.
(h) Exceptions to Requirements Bulletin Specifications
(1) Where the Condition and Compliance Time columns of the
tables in the ``Compliance'' paragraph of Boeing Alert Requirements
Bulletin 777-57A0128 RB, dated June 2, 2025, refers to the original
issue date of Requirements Bulletin 777-57A0128 RB, this AD requires
using the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 777-57A0128 RB,
dated June 2, 2025, specifies contacting Boeing for repair
instructions, this AD requires doing the repair and applicable on-
condition actions using a method approved in accordance with the
procedures specified in paragraph (i) of this AD.
(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 Camille Seay,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 817-222-5149; 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 777-57A0128 RB, dated
June 2, 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 February 23, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-03782 Filed 2-24-26; 8:45 am]
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