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Rule2025-20951

Airworthiness Directives; The Boeing Company Airplanes

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Published

November 25, 2025

Effective

December 10, 2025

Issuing agencies

Transportation DepartmentFederal Aviation Administration

Abstract

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-700, -800, -900, and -900ER series airplanes. This AD was prompted by a report of a runway excursion caused by loss of braking. An inspection found that the right main landing gear (MLG) hydraulic hoses for the brakes were incorrectly installed at the flow limiters, and the left MLG wheel speed transducer wires were also interchanged. This AD requires a general visual inspection (GVI) of the left and right MLG brake hydraulic hoses for any crossed installation, antiskid valve and transducer operational tests, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.

Full Text

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<title>Federal Register, Volume 90 Issue 225 (Tuesday, November 25, 2025)</title>
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[Federal Register Volume 90, Number 225 (Tuesday, November 25, 2025)]
[Rules and Regulations]
[Pages 53215-53218]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-20951]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-5025; Project Identifier AD-2025-01595-T;
Amendment 39-23197; AD 2025-24-02]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain The Boeing Company Model 737-700, -800, -900, and -900ER series
airplanes. This AD was prompted by a report of a runway excursion
caused by loss of braking. An inspection found that the right main
landing gear (MLG) hydraulic hoses for the brakes were incorrectly
installed at the flow limiters, and the left MLG wheel speed transducer
wires were also interchanged. This AD requires a general visual
inspection (GVI) of the left and right MLG brake hydraulic hoses for
any crossed installation, antiskid valve and transducer operational
tests, and applicable on-condition actions. The FAA is issuing this AD
to address the unsafe condition on these products.

DATES: This AD is effective December 10, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 10,
2025.
The FAA must receive comments on this AD by January 9, 2026.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> 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.
<bullet> 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5025; 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 street address for Docket Operations is listed above.
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 <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
<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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5025.

FOR FURTHER INFORMATION CONTACT: Katherine Venegas, Aviation Safety
Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone:
562-627-5353; email: <a href="/cdn-cgi/l/email-protection#056e64716d60776c6b602b73606b60626476456364642b626a73">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments using a method listed under
the ADDRESSES section. Include Docket No. FAA-2025-5025 and Project
Identifier AD-2025-01595-T at the beginning of your comments. The most
helpful comments reference a specific portion of the final rule,
explain the reason for any recommended change, and include supporting
data. The FAA will consider all comments received by the closing date
and may amend this final rule 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
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The
agency will also post a report summarizing each

[[Page 53216]]

substantive verbal contact received about this final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to
Katherine Venegas, Aviation Safety Engineer, FAA, 3960 Paramount
Boulevard, Lakewood, CA 90712; phone: 562-627-5353; email:
<a href="/cdn-cgi/l/email-protection#fd969c8995988f949398d38b9893989a9c8ebd9b9c9cd39a928b">[email&#160;protected]</a>. 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 a report of a runway excursion caused by loss
of braking. An inspection found that the right MLG hydraulic hoses for
the brakes were incorrectly installed (crossed) at the flow limiters,
and the left MLG wheel speed transducer wires were interchanged. This
condition could result in incorrect antiskid system operation, which
could result in loss of braking and potential for a runway excursion
with serious or fatal injuries. The FAA is issuing this AD to address
the unsafe condition on these products.

FAA's Determination

The FAA is issuing this AD because the agency has determined the
unsafe condition described previously is likely to exist or develop in
other products of the same type design.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Boeing Alert Requirements Bulletin 737-32A1599 RB,
dated October 14, 2025. This material specifies procedures for a GVI of
the left and right MLG brake hydraulic hoses for any incorrect
(crossed) installation, antiskid valve and transducer operational
tests, and applicable on-condition actions.
On-condition actions include installing the brake hydraulic hoses
to the correct flow limiter or union, and doing applicable corrective
actions until the operational tests are passed. 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.

AD Requirements

This AD requires accomplishing the actions identified in Boeing
Alert Requirements Bulletin 737-32A1599 RB, dated October 14, 2025,
already described, except as discussed under ``Differences Between this
AD and the Referenced Material.''

Differences Between This AD and the Referenced Material

Although Boeing Alert Requirements Bulletin 737-32A1599 RB, dated
October 14, 2025, does not specify reporting inspection and test
results, reporting is included in Boeing Alert Service Bulletin 737-
32A1599, dated October 14, 2025. The FAA has determined that reporting
is necessary. The number of findings in such reports, and the number of
flight cycles since accomplishing any service bulletin identified in
Appendix A of Boeing Alert Requirements Bulletin 737-32A1599 RB, dated
October 14, 2025, will help inform the FAA as to whether additional
rulemaking may be necessary.

Justification for Immediate Adoption and Determination of the Effective
Date

Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to forego notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies forgoing notice and comment prior to adoption of this rule,
because incorrectly installed (crossed) brake hydraulic hoses for the
MLG and interchanged left MLG wheel speed transducer wires could cause
incorrect antiskid system operation and result in loss of braking and a
runway excursion with serious or fatal injuries. Further, the effects
of crossed brake hoses may not be noticed until there is a skidding
condition. Additionally, the compliance time in this AD is shorter than
the time necessary for the public to comment and for publication of the
final rule. Accordingly, notice and opportunity for prior public
comment are impracticable.
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forgo notice and
comment.

Regulatory Flexibility Act

The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without notice and comment,
RFA analysis is not required.

Costs of Compliance

While 6,816 airplanes are included in the Effectivity of Boeing
Alert Requirements Bulletin 737-32A1599, dated October 14, 2025, and
thus the applicability of this AD, the FAA expects that only
approximately 100 airplanes of U.S. registry are currently in a
configuration that necessitates immediate action and therefore will
incur the following estimated costs.

Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Inspection and tests................ 7 work-hours x $85 per $0 $595 $59,500
hour = $595.
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[[Page 53217]]

The FAA estimates the following costs to do any necessary
installations and reporting that would be required based on the results
of the inspection. The FAA has no way of determining the number of
aircraft that might need reporting:

On-Condition Cost
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Installation.................................. 2 work-hours x $85 per hour = $0 $170
$170.
Reporting..................................... 1 work-hour x $85 per hour = $85 0 85
----------------------------------------------------------------------------------------------------------------

The FAA has received no definitive data on which to base the cost
estimates for on-condition corrective actions to address failed
operational tests specified in this AD.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to take
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.

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, and
(2) Will not affect intrastate aviation in Alaska.

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:

2025-24-02 The Boeing Company: Amendment 39-23197; Docket No. FAA-
2025-5025; Project Identifier AD-2025-01595-T.

(a) Effective Date

This airworthiness directive (AD) is effective December 10,
2025.

(b) Affected ADs

None.

This AD applies to The Boeing Company Model 737-700, -800, -900,
and -900ER series airplanes, certificated in any category, as
identified in Boeing Alert Requirements Bulletin 737-32A1599 RB,
dated October 14, 2025.

(d) Subject

Air Transport Association (ATA) of America Code 32, Landing
gear.

(e) Unsafe Condition

This AD was prompted by a report of a runway excursion caused by
loss of braking. An inspection found that the right main landing
gear (MLG) hydraulic hoses for the brakes were incorrectly installed
(crossed) at the flow limiters, and the left MLG wheel speed
transducer wires were also interchanged. The FAA is issuing this AD
to address incorrectly installed brake hydraulic hoses for the MLG
and wheel speed transducer wires for the MLG, which could cause
incorrect antiskid system operation. The unsafe condition could
result in loss of braking and a runway excursion with serious or
fatal injuries.

(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 737-32A1599 RB, dated October 14, 2025,
do all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
737-32A1599 RB, dated October 14, 2025.
Note 1 to paragraph (g):Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
737-32A1599, dated October 14, 2025, which is referred to in Boeing
Alert Requirements Bulletin 737-32A1599 RB, dated October 14, 2025.

(h) Exception to Requirements Bulletin Specifications

Where the ``Effectivity'' paragraph and Compliance Time columns
of the tables in the ``Compliance'' paragraph of Boeing Alert
Requirements Bulletin 737-32A1599 RB, dated October 14, 2025, refer
to the original issue date of Requirements Bulletin 737-32A1599 RB,
this AD requires using the effective date of this AD.

[[Page 53218]]

(i) Reporting

For airplanes identified as Group 1, Configuration 3 through 5,
in Boeing Alert Requirements Bulletin 737-32A1599 RB, dated October
14, 2025, on which any of the findings specified in paragraphs
(i)(4) through (6) of this AD were found during any inspection or
test required by paragraph (g) of this AD: Submit a report within 30
days after the inspection or test, or within 30 days after the
effective date of this AD, whichever occurs later. The report must
include the items specified in paragraphs (i)(1) through (6) of this
AD. Submit the report to Boeing Service Engineering by sending a
service request using the Boeing Communication System (BCS).
(1) Airplane line number.
(2) Date of most recent accomplishment of any service bulletin
listed in Appendix A of Boeing Alert Requirements Bulletin 737-
32A1599 RB, dated October 14, 2025.
(3) The number of flight cycles between the most recent
accomplishment of any service bulletin listed in Appendix A of
Boeing Alert Requirements Bulletin 737-32A1599 RB, dated October 14,
2025, and the date that the inspection or test was completed.
(4) All crossed brake hydraulic hoses found during the general
visual inspection for crossed brake hydraulic hoses.
(5) Operational test failures of the antiskid valve operational
tests.
(6) Operational test failures of the transducer operational
tests.

(j) 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 (k)(1) of this AD. Information may be emailed to:
<a href="/cdn-cgi/l/email-protection#73323e3c30331512125d141c05">[email&#160;protected]</a>. 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.

(k) Additional Information

(1) For more information about this AD, contact Katherine
Venegas, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard,
Lakewood, CA 90712; phone: 562-627-5353; email:
<a href="/cdn-cgi/l/email-protection#046f65706c61766d6a612a72616a61636577446265652a636b72">[email&#160;protected]</a>.
(2) Material identified in this AD that is not incorporated by
reference is available at the address specified in paragraph (l)(3)
of this AD.

(l) 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 737-32A1599 RB, dated
October 14, 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 <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
(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 <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#187e6a3671766b687d7b6c7177765876796a79367f776e">[email&#160;protected]</a>.

Issued on November 19, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-20951 Filed 11-21-25; 11:15 am]
BILLING CODE 4910-13-P

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