The FAA is adopting a new airworthiness directive (AD) for certain Airbus SAS Model A350-1041 airplanes. This AD was prompted by the detection of missing chamfers under the head...
[Docket No. FAA-2026-8787; Project Identifier MCAI-2025-00836-T; Amendment 39-23452; AD 2026-17-09]
RIN 2120-AA64
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule; request for comments.
SUMMARY:
The FAA is adopting a new airworthiness directive (AD) for certain Airbus SAS Model A350-1041 airplanes. This AD was prompted by the detection of missing chamfers under the heads of critical fasteners on the primary structure of both pylons. This AD requires an inspection of the fasteners in the affected areas and corrective actions if necessary. The FAA is issuing this AD to address the unsafe condition on these products.
DATES:
This AD is effective September 18, 2026.
The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of September 18, 2026.
The FAA must receive comments on this AD by October 19, 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-2026-8787; 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:
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; emailADs@easa.europa.eu.
You may find this material on the EASA website at
ad.easa.europa.eu.
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 atregulations.gov
under Docket No. FAA-2026-8787.
FOR FURTHER INFORMATION CONTACT:
Andrew Younglove, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3644; email:
andrew.e.younglove@faa.gov.
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-2026-8787; Project Identifier MCAI-2025-00836-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
regulations.gov, 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
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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 Andrew Younglove, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3644; email:
andrew.e.younglove@faa.gov.
Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.
Background
EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2025-0106, dated May 7, 2025 (EASA AD 2025-0106) (also referred to as the MCAI), to correct an unsafe condition for certain Airbus SAS Model A350-1041 airplanes. The MCAI states that during visual inspections, missing chamfers under the heads of critical fasteners on the primary structure of both the left-hand (LH) and right-hand (RH) pylons of A350-1041 airplanes were detected. This discrepancy could be attributed to a programming error or improper maintenance of cutting tools, which could result in improper fastener installation, potentially compromising the long-term structural integrity of the pylon. This condition, if not detected and corrected, could lead to reduced fatigue life, which could adversely affect the structural integrity of the airplane.
The FAA is issuing this AD to address the unsafe condition on these products.
You may examine the MCAI in the AD docket at
regulations.gov
under Docket No. FAA-2026-8787.
Material Incorporated by Reference Under 1 CFR Part 51
EASA AD 2025-0106 specifies procedures for conducting a detailed inspection of the gap under the fastener heads in the affected areas (
i.e.,
primary structure of the LH and RH pylons) and corrective actions if any discrepancy (
i.e.,
the gap is not within the allowable limits) is detected. Corrective actions include contacting the manufacturer 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.
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 requires accomplishing the actions specified in EASA AD 2025-0106 described previously, except for any differences identified as exceptions in the regulatory text of this AD.
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 2025-0106 is incorporated by reference in this AD. This AD requires compliance with EASA AD 2025-0106 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 2025-0106 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 2025-0106. Material required by EASA AD 2025-0106 for compliance will be available at
regulations.gov
under Docket No. FAA-2026-8787 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. 551et 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 provides the following cost estimates to comply with this AD:
Estimated Costs for Required Actions
Labor cost
Parts cost
Cost per product
8 work-hours × $85 per hour = $680
$0
$680
The FAA has received no definitive data on which to base the cost estimates for the 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
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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:
This airworthiness directive (AD) is effective September 18, 2026.
(b) Affected ADs
None.
(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 2025-0106, dated May 7, 2025 (EASA AD 2025-0106).
(d) Subject
Air Transport Association (ATA) of America Code 54, Wings.
(e) Unsafe Condition
This AD was prompted by the detection of missing chamfers under the heads of critical fasteners on the primary structure of both pylons. The FAA is issuing this AD to address missing chamfers on the left-hand (LH) and right-hand (RH) pylons. This condition, if not detected and corrected, could lead to reduced fatigue life, which could adversely affect the structural integrity 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 2025-0106.
(h) Exceptions to EASA AD 2025-0106
(1) Where paragraph (2) of EASA AD 2025-0106 specifies “any discrepancy is detected”, this AD requires replacing that text with “the gap under any fastener head in the affected areas is not within the allowable limits”.
(2) This AD does not adopt the “Remarks” section of EASA AD 2025-0106.
(i) No Reporting Requirement
Although the material referenced in EASA AD 2025-0106 specifies to submit certain information to the manufacturer, this AD does not include that requirement.
(j) 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 the Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (k) of this AD and email to:
AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.
(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 Branch, 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 paragraphs (i) and (j)(2) of this AD, if any material contains procedures or tests that are identified as RC, those procedures and tests must be done to comply with this AD; any procedures or tests that are not identified as RC are recommended. Those procedures and tests that are 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 procedures and tests identified as RC can be done and the airplane can be put back in an airworthy condition. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC.
(k) Additional Information
For more information about this AD, contact Andrew Younglove, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3644; email:
andrew.e.younglove@faa.gov.
(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 this AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2025-0106, dated May 7, 2025.
(ii) [Reserved]
(3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email
ADs@easa.europa.eu.
You may find this material on the EASA website at
ad.easa.europa.eu.
(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.
Use this for formal legal and research references to the published document.
91 FR 56581
Web Citation
Suggested Web Citation
Use this when citing the archival web version of the document.
“Airworthiness Directives; Airbus SAS Airplanes,” thefederalregister.org (September 3, 2026), https://thefederalregister.org/documents/2026-18055/airworthiness-directives-airbus-sas-airplanes.