Airworthiness Directives; Airbus SAS Airplanes

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0912; Project Identifier MCAI-2024-00571-T; Amendment 39-23178; AD 2025-22-01]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Airbus SAS Airplanes</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is adopting a new airworthiness directive (AD) for all Airbus SAS Model A350-941 and -1041 airplanes. This AD was prompted by reports of mechanical noises originating from the nose landing gear (NLG) shock absorber during ground maneuvers. This AD requires repetitive inspections ( <E T="03">i.e.,</E> steering checks) of the NLG shock absorber and applicable on-condition actions. This AD also limits the installation of affected parts under certain conditions. The FAA is issuing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This AD is effective January 2, 2026. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 2, 2026. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0912; 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 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. <E T="03">Material Incorporated by Reference:</E> • 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 <E T="03">ADs@easa.europa.eu.</E> You may find this material on the EASA website at <E T="03">ad.easa.europa.eu.</E> • 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 <E T="03">regulations.gov</E> under Docket No. FAA-2025-0912. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Stefanie Roesli, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3964; email: <E T="03">stefanie.n.roesli@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus SAS Model A350-941 and -1041 airplanes. The NPRM was published in the <E T="04">Federal Register</E> on May 21, 2025 (90 FR 21702). The NPRM was prompted by AD 2025-0093, dated April 24, 2025 (EASA AD 2025-0093) (also referred to as the MCAI), issued by EASA, which is the Technical Agent for the Member States of the European Union. The MCAI reports instances of mechanical noises originating from the NLG shock absorber during ground maneuvers. Further analysis traced these noises to higher than expected friction between the lower bearing carrier (LBC) and the main fitting of the sliding tube. This friction may cause deformation of the LBC's anti-rotation tabs, leading to relative movement between the LBC and the main fitting. As a result, wear on the corrosion protection coating of the main fitting may occur due to subsequent movement of the retainer ring positioned between these components, which could lead to corrosion of the NLG main fitting. In the NPRM, the FAA proposed to require repetitive inspections ( <E T="03">i.e.,</E> steering checks) of the NLG shock absorber and applicable on-condition actions and limit the installation of affected parts under certain conditions, as specified in EASA AD 2025-0093. The FAA is issuing this AD to address higher than expected friction on the NLG shock absorber LBC, which could result in deformation of the LBC's anti-rotation tabs and consequent corrosion of the NLG main fitting. The unsafe condition, if not addressed, could lead to structural failure of the NLG, which may result in damage to the airplane and injury to occupants. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0912. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received a comment from the Air Line Pilots Association, International (ALPA) who supported the NPRM without change. The FAA received additional comments from Delta Air Lines (Delta). The following presents those comments and the FAA's responses. <HD SOURCE="HD1">Request To Clarify if a Certain Service Bulletin Provides Terminating Action</HD> Delta requested the FAA clarify whether modifications performed using Liebherr Service Bulletin 6407A-32-01, dated May 27, 2025, and any future service bulletin modifications may be used as terminating action for the requirements of the proposed AD. Delta noted that the Liebherr service bulletin provides instructions for modifying certain affected parts to not affected parts, which effectively changes a Group 1 or 3 airplane to a Group 4 airplane. Delta noted that EASA AD 2025-0093 specifies Group 4 airplanes are only subject to the parts prohibition requirement. Delta asserted that the intent of the affected part, not affected part, and group definitions is to allow retrofit of an airplane to become a Group 4 airplane once a modification is developed, such as the one in the Liebherr service bulletin. Delta also asked whether other methods, such as other Airbus service bulletins or replacement of a NLG assembly with one that does not have affected parts installed, could similarly be used to convert a Groups 1 through 3 airplane to a Group 4 airplane. The FAA acknowledges that if an “Affected part” is replaced with a “Not affected part,” then the airplane would become a Group 4 airplane per the definitions in EASA AD 2025-0093 and the repetitive checks and reporting would no longer need to be accomplished for that airplane. However, the FAA has not received or reviewed Liebherr Service Bulletin 6407A-32-01 to determine if accomplishing the modification in that service bulletin is acceptable as a terminating action for the repetitive checks and reporting required by this AD. Further, the FAA has not received, reviewed, or approved any other service information that would potentially provide a terminating action. Therefore, the FAA declines to revise this AD to allow the Liebherr service bulletin as a terminating action. However, under the provisions of paragraph (i)(1) of this AD, an operator may propose terminating action as an alternative method of compliance (AMOC) for the requirements of this AD. If sufficient substantiating data is provided and an equivalent level of safety is demonstrated, the FAA may approve such AMOC requests to allow for termination of the required actions in this AD. The FAA has not changed the AD in response to this comment. <HD SOURCE="HD1">Request To Remove Reporting Requirement</HD> Delta requested the FAA add a paragraph to the proposed AD stating that the reporting requirement specified in paragraph (5) of EASA AD 2025-0093 is not adopted. Delta reasoned that reporting is not necessary since Airbus does not need to collect additional data to determine the root cause or final solution because EASA AD 2025-0093 already identifies a final solution in the “Not affected part” definition; and that such parts can be installed in service using Liebherr Service Bulletin 6407A-32-01, dated May 27, 2025. Delta also reasoned reporting is not necessary because there is no list of bad serial numbers, so Airbus does not need to maintain a bad parts pool. Delta concluded that, while Airbus may want operators to continue reporting to assist with tracking spare parts, the reporting requirement does not appear to contribute to an enhanced level of safety. The FAA disagrees with removing the reporting requirement from this AD. The FAA notes that reporting is required only if there is a discrepancy as specified in paragraph (5) of EASA AD 2025-0093. Although the EASA AD identifies “not affected” parts, the EASA AD does not indicate that a final fix or permanent solution has been developed. Further, the FAA has received no information indicating that Airbus has established a terminating action at this time. Therefore, the FAA considers the reporting requirement necessary to continue gathering data relevant to the unsafe condition. However, the FAA has added a new paragraph (h)(4) to this AD to provide a 30-day grace period for operators who may have accomplished the steering check before the effective date of the AD. <HD SOURCE="HD1">Request To Clarify Which Instructions Are Required for Compliance</HD> Delta requested the FAA clarify which portions of Airbus Alert Operators Transmission (AOT) A32P031-24, Revision 04, dated March 11, 2025, are required for compliance with the proposed AD. Delta noted the AOT indicates section 5.6, including the flowchart, is labeled as required for compliance (RC). Delta also noted EASA AD 2025-0093 specifies accomplishing a steering check of the affected part and applicable corrective actions in accordance with the instructions of the AOT. Delta interprets this to mean that only the portions of the AOT related to the steering check and corrective actions are required. Delta expressed concern with the first qu ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 26k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━