[Federal Register Volume 90, Number 189 (Thursday, October 2, 2025)]
[Rules and Regulations]
[Pages 47538-47540]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-19392]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1358; Project Identifier AD-2025-00620-T;
Amendment 39-23152; AD 2025-19-12]
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 737-600, -700, -700C, -800, -900, and -900ER
series airplanes. This AD was prompted by a report of improper grinding
of the inner diameter of the main landing gear (MLG) outer cylinders,
resulting in possible heat damage to the outer cylinders. This AD
requires a records check or inspection to determine if an affected
outer cylinder is installed and replacing all affected outer cylinders.
The FAA is issuing this AD to address the unsafe condition on these
products.
DATES: This AD is effective November 6, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 6,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2025-1358; 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:
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.
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-2025-1358.
[[Page 47539]]
FOR FURTHER INFORMATION CONTACT: Stefanie Roesli, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3964; 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 737-600, -700, -700C, -800, -900, and -900ER series airplanes.
The NPRM was published in the Federal Register on July 8, 2025 (90 FR
30027). The NPRM was prompted by a report of improper grinding of the
inner diameter of the MLG outer cylinders, resulting in possible heat
damage to the outer cylinders. In the NPRM, the FAA proposed to require
a records check or inspection to determine if an affected outer
cylinder is installed and replacing all affected outer cylinders. The
FAA is issuing this AD to address heat damage to the MLG outer
cylinders. The unsafe condition, if not addressed, could cause failure
of a principal structural element to sustain its limit load or collapse
of the MLG, which could result in loss of control of the airplane or
runway departure.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from the Air Line Pilots Association,
International (ALPA) and Boeing who supported the NPRM without change.
The FAA received an additional comment from Aviation Partners
Boeing (APB). The following presents the comment received on the NPRM
and the FAA's response to the comment.
Effect of Winglets on Accomplishment of the Proposed Actions
APB stated that the installation of winglets per Supplemental Type
Certificate (STC) ST00830SE does not affect accomplishment of the
actions specified in the proposed AD.
The FAA agrees that STC ST00830SE does not affect the ability to
accomplish the actions required by this AD. The FAA has not changed the
AD in this regard.
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, 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 737-32A1585 RB,
dated January 15, 2024. This material specifies procedures for
performing a maintenance records check or an inspection of the left and
right MLG outer cylinders to determine if any affected part numbers and
serial numbers are installed and replacing affected outer cylinders.
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 1,833 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspection or maintenance records 2 work-hours x $85 per $0 $170 $311,610
check for affected parts. hour = $170.
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The FAA estimates the following costs to do any replacement that
would be required based on the results of the inspection or maintenance
records check. The agency has no way of determining the number of
airplanes that might need this replacement:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
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Replacement of MLG outer cylinder (166 62 work-hours x $85 per $265,000 $270,270 per MLG outer
affected parts). hour = $5,270. cylinder.
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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
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
[[Page 47540]]
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:
2025-19-12 The Boeing Company: Amendment 39-23152; Docket No. FAA-
2025-1358; Project Identifier AD-2025-00620-T.
(a) Effective Date
This airworthiness directive (AD) is effective November 6, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any
category.
(d) Subject
Air Transport Association (ATA) of America Code 32, Landing
Gear.
(e) Unsafe Condition
This AD was prompted by a report of improper grinding of the
inner diameter of the main landing gear (MLG) outer cylinders,
resulting in possible heat damage to the outer cylinder. The FAA is
issuing this AD to address heat damage to the MLG outer cylinders.
The unsafe condition, if not addressed, could cause failure of a
principal structural element to sustain its limit load or collapse
of the MLG, which could result in loss of control of the airplane or
runway departure.
(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 737-32A1585 RB, dated January 15, 2024,
do all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
737-32A1585 RB, dated January 15, 2024.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
737-32A1585, dated January 15, 2024, which is referred to in Boeing
Alert Requirements Bulletin 737-32A1585 RB, dated January 15, 2024.
(h) Exception to Requirements Bulletin Specifications
Where the ``Boeing Recommended Compliance Time'' column in the
table under the ``Compliance'' paragraph of Boeing Alert
Requirements Bulletin 737-32A1585 RB, dated January 15, 2024, refers
to the original issue date of Boeing Alert Requirements Bulletin
737-32A1585 RB, this AD requires using the effective date 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 certification office,
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) Related Information
(1) For more information about this AD, contact Stefanie Roesli,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 206-231-3964; 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)
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 737-32A1585 RB, dated
January 15, 2024.
(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 19, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-19392 Filed 10-1-25; 8:45 am]
BILLING CODE 4910-13-P