Rule2025-20924
Airworthiness Directives; Airbus SAS Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
November 25, 2025
Effective
December 10, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is superseding Airworthiness Directive (AD) 2022-22- 09, which applied to certain Airbus SAS Model A350-1041 airplanes. AD 2022-22-09 required replacing affected hydro-mechanical units (HMUs) with serviceable HMUs before reaching a reduced life limit and limited the installation of affected parts under certain conditions. Since the FAA issued AD 2022-22-09, an improved HMU was developed and embodied in production. This AD continues to require the actions in AD 2022-22-09. This AD also requires replacing affected HMUs with improved HMUs and prohibits the installation of affected parts under certain conditions and on certain airplanes. 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 53203-53206]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-20924]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-3423; Project Identifier MCAI-2025-00811-T;
Amendment 39-23162; AD 2025-20-09]
RIN 2120-AA64
Airworthiness Directives; Airbus SAS Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2022-22-
09, which applied to certain Airbus SAS Model A350-1041 airplanes. AD
2022-22-09 required replacing affected hydro-mechanical units (HMUs)
with serviceable HMUs before reaching a reduced life limit and limited
the installation of affected parts under certain conditions. Since the
FAA issued AD 2022-22-09, an improved HMU was developed and embodied in
production. This AD continues to require the actions in AD 2022-22-09.
This AD also requires replacing affected HMUs with improved HMUs and
prohibits the installation of affected parts under certain conditions
and on certain airplanes. 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-2025-3423; 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, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.
Material Incorporated by Reference:
<bullet> For European Union Aviation Safety Agency (EASA) material
identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668
Cologne, Germany; telephone +49 221 8999 000; email <a href="/cdn-cgi/l/email-protection#0b4a4f784b6e6a786a256e7e79647b6a256e7e"><span class="__cf_email__" data-cfemail="6524211625000416044b0010170a15044b0010">[email protected]</span></a>.
You may find this material on the EASA website at ad.easa.europa.eu.
<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-2025-3423.
FOR FURTHER INFORMATION CONTACT: Kathryn Hill, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3626; email: <a href="/cdn-cgi/l/email-protection#3853594c504a415616591650515454785e5959165f574e"><span class="__cf_email__" data-cfemail="a6cdc7d2ced4dfc888c788cecfcacae6c0c7c788c1c9d0">[email protected]</span></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-2025-3423; Project
Identifier MCAI-2025-00811-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 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 Kathryn
Hill, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines,
WA 98198; phone: 206-231-3626; email: <a href="/cdn-cgi/l/email-protection#d1bab0a5b9a3a8bfffb0ffb9b8bdbd91b7b0b0ffb6bea7"><span class="__cf_email__" data-cfemail="b4dfd5c0dcc6cdda9ad59adcddd8d8f4d2d5d59ad3dbc2">[email protected]</span></a>. Any
commentary that the FAA receives which is not specifically designated
as CBI will be placed in the public docket for this rulemaking.
[[Page 53204]]
Background
The FAA issued AD 2022-22-09, Amendment 39-22224 (87 FR 72377,
November 25, 2022) (AD 2022-22-09), for Airbus SAS Model A350-1041
airplanes equipped with Rolls-Royce Trent XWB-97 engines. AD 2022-22-09
was prompted by an MCAI originated by EASA, which is the Technical
Agent for the Member States of the European Union. EASA issued AD 2022-
0040, dated March 8, 2022 (EASA AD 2022-0040), to correct an unsafe
condition. AD 2022-22-09 was prompted by reports of rejected takeoffs
after transient engine N1 shaft speed exceedance, which was found to be
the result of piston wear, causing the combining spill valve (CSV)
piston of the engine HMU to close slowly. EASA AD 2022-0040 stated
investigations revealed that the CSV of the engine HMU was slow to
close due to piston wear. A worn CSV piston does not move fully and
freely over its operating range, and, when it moves to fully closed
position, an excess of fuel is sent to the fuel nozzles which
eventually results in an N1 transient shaft overspeed.
AD 2022-22-09 required replacing certain HMUs with serviceable HMUs
before reaching a reduced life limit. The FAA issued AD 2022-22-09 to
address a stuck CSV piston of the engine HMUs, which could
significantly reduce engine thrust, and if combined with a loss of the
second engine, could possibly result in reduced control of the
airplane.
Actions Since AD 2022-22-09 Was Issued
The preamble to AD 2022-22-09 specifies that the FAA considers that
AD ``interim action'' and that the FAA might consider further
rulemaking if a final action is identified. Since the FAA issued AD
2022-22-09, EASA superseded AD 2022-0040 with EASA AD 2025-0100, dated
April 30, 2025 (EASA AD 2025-0100) (also referred to as the MCAI), to
correct an unsafe condition for Airbus SAS Model A350-1041 airplanes
equipped with Rolls-Royce Trent XWB-97 engines. The MCAI states, since
issuance of EASA AD 2022-0040, an improved HMU has been developed and
embodied in production through Airbus modification 120423. In addition,
Rolls-Royce published Rolls-Royce Modification Service Bulletin TRENT
XWB 73-L044 to provide instructions for replacement of an affected HMU
with an improved HMU, as a terminating action for replacement of the
life-limited affected parts. The FAA has now determined that further
rulemaking is necessary, and this AD follows from that determination.
The FAA is issuing this AD to address the unsafe condition on these
products. You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a>
under Docket No. FAA-2025-3423.
Explanation of Retained Requirements
Although this AD does not explicitly restate the requirements of AD
2022-22-09, this AD retains all of the requirements of AD 2022-22-09.
Those requirements are referenced in EASA AD 2025-0100, which, in turn,
is referenced in paragraph (g) of this AD.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2025-0100, which specifies procedures for
replacing an HMU having part number (P/N) G5020HMU02 with either a
serviceable HMU, or an improved HMU having P/N G5020HMU03, or any later
approved part number. EASA AD 2025-0100 also prohibits the installation
of an affected HMU after it is replaced with an improved HMU.
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.
FAA's Determination
These products have been approved by the civil aviation authority
of another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, that authority has notified the FAA of the unsafe condition
described in the MCAI referenced above. The FAA is issuing this AD
after determining that the unsafe condition described previously is
likely to exist or develop on other products of the same type design.
Requirements of This AD
This AD retains all requirements of AD 2022-22-09. This AD requires
accomplishing the actions specified in EASA AD 2025-0100 described
previously, except for any differences identified as exceptions in the
regulatory text of this AD. This AD also prohibits the installation of
affected parts under certain conditions.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result,
EASA AD 2025-0100 is incorporated by reference in this AD. This AD
requires compliance with EASA AD 2025-0100 in its entirety through that
incorporation, except for any differences identified as exceptions in
the regulatory text of this AD. Using common terms that are the same as
the heading of a particular section in EASA AD 2025-0100 does not mean
that operators need comply only with that section. For example, where
the AD requirement refers to ``all required actions and compliance
times,'' compliance with this AD requirement is not limited to the
section titled ``Required Action(s) and Compliance Time(s)'' in EASA AD
2025-0100. Material required by EASA AD 2025-0100 for compliance will
be available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-3423 after
this AD is published.
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 dispense with 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.
There are currently no domestic operators of these products.
Accordingly, notice and opportunity for prior public comment are
unnecessary, pursuant to 5 U.S.C. 553(b). In addition, for the
foregoing reason(s), 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.
Regulatory Flexibility Act (RFA)
The requirements of the 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
Currently, there are no affected U.S.-registered airplanes. If an
affected airplane is imported and placed on the U.S. Register in the
future, the FAA
[[Page 53205]]
provides the following cost estimates to comply with this AD:
Estimated Costs for Required Actions
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Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Retained actions from AD 2022-22-09........... Up to 7 work-hours x $85 per * $0 $595
hour = $595.
New actions................................... Up to 2 work-hours x $85 per * 0 170
hour = $170.
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* The FAA has received no definitive data on which to base the cost estimates for the parts 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, 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:
0
a. Removing Airworthiness Directive (AD) 2022-22-09, Amendment 39-22224
(87 FR 72377, November 25, 2022); and
0
b. Adding the following new AD:
2025-20-09 Airbus SAS: Amendment 39-23162; Docket No. FAA-2025-3423;
Project Identifier MCAI-2025-00811-T.
(a) Effective Date
This airworthiness directive (AD) is effective December 10,
2025.
(b) Affected ADs
This AD replaces AD 2022-22-09, Amendment 39-22224 (87 FR 72377,
November 25, 2022) (AD 2022-22-09).
(c) Applicability
This AD applies to Airbus SAS Model A350-1041 airplanes,
certificated in any category, as identified in European Union
Aviation Safety Agency (EASA) AD 2025-0100, dated April 30, 2025
(EASA AD 2025-0100).
(d) Subject
Air Transport Association (ATA) of America Code 73, Engine Fuel
and Control.
(e) Unsafe Condition
This AD was prompted by reports of rejected takeoffs after
transient engine N1 shaft speed exceedance. The FAA is issuing this
AD to address a stuck combining spill valve piston of the engine
hydro-mechanical units, which could significantly reduce engine
thrust, and if combined with a loss of the second engine, could
possibly result in reduced control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
Except as specified in paragraph (h) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with, EASA AD 2025-0100.
(h) Exceptions to EASA AD 2025-0100
(1) Where EASA AD 2025-0100 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where paragraph (3) of EASA AD 2025-0100 refers to March 15,
2022 (the effective date of EASA AD 2022-0040, dated March 8, 2022),
this AD requires using December 30, 2022 (the effective date of FAA
AD 2022-22-09).
(3) This AD does not adopt the ``Remarks'' section of EASA AD
2025-0100.
(i) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): 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
Continued Operational Safety Branch, send it to the attention of the
person identified in paragraph (j) of this AD and email to:
<a href="/cdn-cgi/l/email-protection#4f0e02000c0f292e2e61282039"><span class="__cf_email__" data-cfemail="36777b79757650575718515940">[email protected]</span></a>.
(2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, AIR-520,
Continued Operational Safety, FAA; or EASA; or Airbus SAS's EASA
Design Organization Approval (DOA). If approved by the DOA, the
approval must include the DOA-authorized signature.
(3) Required for Compliance (RC): Except as required by
paragraph (i)(2) of this AD, if any material referenced in EASA AD
2025-0100 that contains paragraphs that are labeled as RC, the
instructions in RC paragraphs, including subparagraphs under an RC
paragraph, must be done to comply with this AD; any paragraphs,
including subparagraphs under those paragraphs, that are not
identified as RC are recommended. The instructions in paragraphs,
including subparagraphs under those paragraphs, not identified as RC
may be deviated from using accepted methods in accordance with the
operator's maintenance or inspection program without obtaining
approval of an AMOC, provided the instructions identified as RC can
be done and the airplane can be put back in an airworthy condition.
Any substitutions or changes to instructions identified as RC
require approval of an AMOC.
[[Page 53206]]
(j) Additional Information
For more information about this AD, contact Kathryn Hill,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 206-231-3626; email: <a href="/cdn-cgi/l/email-protection#96fdf7e2fee4eff8b8f7b8fefffafad6f0f7f7b8f1f9e0"><span class="__cf_email__" data-cfemail="bdd6dcc9d5cfc4d393dc93d5d4d1d1fddbdcdc93dad2cb">[email protected]</span></a>.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) 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 this AD specifies otherwise.
(3) The following material was approved for IBR on December 10,
2025.
(i) European Union Aviation Safety Agency (EASA) AD 2025-0100,
dated April 30, 2025.
(ii) [Reserved]
(4) For EASA material identified in this AD, contact EASA,
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221
8999 000; email <a href="/cdn-cgi/l/email-protection#f2b3b681b297938193dc9787809d8293dc9787"><span class="__cf_email__" data-cfemail="c9888dba89aca8baa8e7acbcbba6b9a8e7acbc">[email protected]</span></a>. You may find this material on
the EASA website at ad.easa.europa.eu.
(5) 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.
(6) 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#2a4c58044344595a4f495e4345446a444b584b044d455c"><span class="__cf_email__" data-cfemail="91f7e3bff8ffe2e1f4f2e5f8feffd1fff0e3f0bff6fee7">[email protected]</span></a>.
Issued on September 26, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-20924 Filed 11-24-25; 8:45 am]
BILLING CODE 4910-13-P
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