AD 2026-07-08 ACTIVE

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. This AD was prompted by a report of a structural crack in the vertical attachment spar of the tail fin. This AD requires repetitive inspections of certain vertical upper fin spars and, depending on the results, corrective action. This AD also prohibits installing certain upper fin assemblies. The FAA is issuing this AD to address the unsafe condition on these products.

Final rule.

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2026-07-08 Airbus Helicopters: Amendment 39-23303; Docket No. FAA-2025-5039; Project Identifier MCAI-2024-00426-R. (a) Effective Date This airworthiness directive (AD) is effective May 11, 2026. (b) Affected ADs This AD affects AD 2025-24-04, Amendment 39-23199 (90 FR 56679, December 8, 2025) (AD 2025-24-04). (c) Applicability This AD applies to Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 5531, Vertical Stabilizer, Spar/Rib Structure. (e) Unsafe Condition This AD was prompted by a report of a structural crack in the vertical attachment spar of the tail fin. The FAA is issuing this AD to address cracking in the upper fin spar. This condition, if not addressed, could lead to in-flight separation of the upper part of the vertical fin, which could result in loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Requirements Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2023-0154R1, dated July 19, 2024 (EASA AD 2023-0154R1). (h) Exceptions to EASA AD 2023-0154R1 (1) Where EASA AD 2023-0154R1 defines an "affected part," this AD requires replacing that text with "an upper fin assembly having a part number (P/N) identified in the Applicability, Accomplishment Procedure, of Airbus Helicopters Emergency Alert Service Bulletin EASB AS355-05-00-0001, Issue 001, dated July 25, 2023, or Issue 002, dated July 9, 2024, or an upper fin assembly having a P/N that cannot be determined". Note 1 to paragraph (h)(1): MOD 0720098 involves installing a new upper fin that has a reinforced fin spar (P/N 355A14-0522-1751) that is not affected by this AD. Airbus Helicopters Alert Service Bulletin No. AS355-55.00.18, Revision 1, dated June 6, 2024, contains information regarding MOD 0720098. (2) Where EASA AD 2023-0154R1 refers to August 3, 2023 (the effective date of EASA AD 2023-0154, dated July 27, 2023), this AD requires using the effective date of this AD. (3) Where EASA AD 2023-0154R1 requires compliance in terms of flight hours, this AD requires using hours time-in-service. (4) Where paragraph (3) of EASA AD 2023-0154R1 specifies "following the Rotorcraft Flight Manual (RFM) amendment as required by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, it is allowed to exceed the temporary reduced Vne during a maintenance flight", this AD requires replacing that text with "following the Rotorcraft Flight Manual (RFM) amendment required by AD 2025-24-04, it is allowed to exceed the temporary reduced Velocity Never Exceed (V NE ) during a flight to perform an operational check as specified in 14 CFR 91.407". (5) Where paragraphs (3.1), (3.2), and (3.3) of EASA AD 2023-0154R1 specify "maintenance flight", this AD requires replacing that text with "flight to perform an operational check as specified in 14 CFR 91.407". (6) Where paragraph (4) of EASA AD 2023-0154R1 specifies "if, following the RFM amendment as required by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, the temporary reduced Vne is exceeded on a helicopter", this AD requires replacing that text with "if, following the RFM amendment required by AD 2025-24-04, the temporary reduced V NE is exceeded on a helicopter". (7) Where Note 1 of EASA AD 2023-0154R1 specifies "It is allowed to temporarily remove the RFM amendment and the placard, as required by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, to allow maintenance flight(s) during which the temporarily reduced Vne may be exceeded", this AD requires replacing that text with "It is allowed to temporarily remove the RFM amendment and the placard required by AD 2025-24-04 to allow flight(s) to perform an operational check as specified in 14 CFR 91.407, during which the temporarily reduced V NE may be exceeded". Note 2 to paragraph (h)(7): Refer to AD 2025-24-04 for requirements pertaining to exceeding V NE 110 kts. Airbus Helicopters Emergency Alert Service Bulletin EASB AS355-05-00-0001, Issue 002, dated July 9, 2024, also contains information regarding exceeding V NE 110 kts. (8) Instead of complying with paragraph (6) of EASA AD 2023-0154R1, if there is a crack as a result of the inspections required by paragraphs (1) through (4) of EASA AD 2023-0154R1, this AD requires, before further flight, removing the upper fin from service and installing upper fin assembly P/N 355A14-0522-1751 in accordance with paragraph (7) and Note 2 of EASA AD 2023-0154R1. (9) Where Note 2 of EASA AD 2023-0154R1 specifies "paragraph (12) of EASA AD 2024-0139", this AD requires replacing that text with "AD 2025-24-04". (10) This AD does not adopt the "Remarks" section of EASA AD 2023-0154R1. (i) No Reporting Requirement Although the material referenced in EASA AD 2023-0154R1 specifies to submit certain information to the manufacturer, this AD does not include that requirement. (j) Special Flight Permits Special flight permits are prohibited. (k) Alternative Methods of Compliance (AMOCs) (1) The Manager, International Validation 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 local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, send it to the attention of the person identified in paragraph (l)(1) of this AD and email to: AMOC@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (l) Related Information (1) For more information about this AD, contact Yves Petiote, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (202) 975-4867; email: yves.petiote@faa.gov. (2) Airbus Helicopters material identified in this AD that is not incorporated by reference is available at Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-0000 or (800) 232-0323; fax: (972) 641-3775; website airbus.com/en/products-services/helicopters/hcare-services/airbusworld. (m) 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 2023-0154R1, dated July 19, 2024. (ii) [Reserved] (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find the EASA material on the EASA website at ad.easa.europa.eu. (4) You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. (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 fr.inspection@nara.gov. Issued on March 31, 2026. Christopher R. Parker, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-06621 Filed 4-3-26; 8:45 am]BILLING CODE 4910-13-P

Background The FAA issued a notice proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. The NPRM was published in the Federal Register on December 17, 2025 (90 FR 58519). The NPRM was prompted by EASA AD 2023-0154R1, dated July 19, 2024 (EASA AD 2023-0154R1) (also referred to as the MCAI), issued by EASA, which is the Technical Agent for the Member States of the European Union. The MCAI advises of a report of a structural crack (not a complete failure) in the vertical attachment spar of the tail fin. The MCAI states that the unsafe condition, if not addressed, may lead to in-flight separation of the upper part of the vertical fin, which could result in loss of control of the helicopter. EASA has issued related EASA AD 2024-0139, dated July 12, 2024 (EASA AD 2024-0139), for these same model helicopters as well as certain Model AS350B3 helicopters, to address cracking in a different area of the upper fin spar as well as the fin's front attachment screws. The FAA issued AD 2025-24-04, Amendment 39-23199 (90 FR 56679, December 8, 2025) (AD 2025-24-04), to address EASA AD 2024-0139. This AD includes actions that would be contingent on some of the required actions in AD 2025-24-04. In the NPRM, the FAA proposed to require repetitive inspections of certain vertical upper fin spars and, depending on the results, corrective action. The FAA also proposed to prohibit installing certain upper fin assemblies. 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-2025-5039. Discussion of Final Airworthiness Directive Comments The FAA received comments from four commenters. The commenters were two anonymous commenters and two individual commenters. The commenters supported the NPRM without change. Conclusion 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 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 EASA AD 2023-0154R1, which specifies procedures for removing the tail gear box (TGB) fairing and the rear fairing from the tail boom, cleaning, and inspecting the right-hand external side around the two top screws of certain upper fin spars for a crack. EASA AD 2023-0154R1 also specifies procedures for conducting repetitive borescope inspections of that upper fin spar area for a crack or repeating the initial inspection as an alternative. Additionally, EASA AD 2023-0154R1 specifies accomplishing the inspections before and after maintenance flights that exceed the reduced Velocity Never Exceed (V NE ) required by EASA AD 2024-0139 and before the next flight following any other exceedance of the reduced V NE required by EASA AD 2024-0139. Depending on the results of an inspection, EASA AD 2023-0154R1 specifies procedures for marking the two top right-hand screw ends or replacing the upper fin. EASA AD 2023-0154R1 further specifies that installing an upper fin assembly part number (P/N) 355A14-0522-1751 constitutes terminating action for its repetitive inspection requirements and prohibits installing certain upper fin assemblies on any helicopter. 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. Differences Between This AD and the MCAI Where the MCAI defines an affected part as those listed in any revision of the manufacturer's service information, this AD defines an affected part as those listed in specific versions of the manufacturer's service information and would include upper fin assemblies for which the P/N cannot be determined. Costs of Compliance The FAA estimates that this AD affects 177 helicopters of U.S. registry. Labor rates are estimated at $85 per hour. Based on these numbers, the FAA estimates the following costs to comply with this AD. Initial cleaning and inspection of the vertical fin spar and, if necessary, application of a paint mark on the top two right-hand screw ends takes 2.5 work-hours for an estimated cost of $213 per helicopter and $37,701 for the U.S. fleet. Repetitive borescope inspection of the upper fin spar takes 0.5 work-hour for an estimated cost of $43 per helicopter and up to $7,611 for the U.S. fleet, per inspection cycle. Alternatively, repeating the initial inspection takes 2.5 work-hours for an estimated cost of $213 per helicopter and up to $37,701 for the U.S. fleet, per inspection cycle. If required, removing the upper fin from service and installing upper fin assembly P/N 355A14-0522-1751 to modify the upper fin takes 40 work-hours and parts cost $25,360 for an estimated cost of $28,760 per helicopter. The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. 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 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 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2026-07-08 Airbus Helicopters: Amendment 39-23303; Docket No. FAA-2025-5039; Project Identifier MCAI-2024-00426-R. (a) Effective Date This airworthiness directive (AD) is effective May 11, 2026. (b) Affected ADs This AD affects AD 2025-24-04, Amendment 39-23199 (90 FR 56679, December 8, 2025) (AD 2025-24-04). (c) Applicability This AD applies to Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 5531, Vertical Stabilizer, Spar/Rib Structure. (e) Unsafe Condition This AD was prompted by a report of a structural crack in the vertical attachment spar of the tail fin. The FAA is issuing this AD to address cracking in the upper fin spar. This condition, if not addressed, could lead to in-flight separation of the upper part of the vertical fin, which could result in loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Requirements Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2023-0154R1, dated July 19, 2024 (EASA AD 2023-0154R1). (h) Exceptions to EASA AD 2023-0154R1 (1) Where EASA AD 2023-0154R1 defines an "affected part," this AD requires replacing that text with "an upper fin assembly having a part number (P/N) identified in the Applicability, Accomplishment Procedure, of Airbus Helicopters Emergency Alert Service Bulletin EASB AS355-05-00-0001, Issue 001, dated July 25, 2023, or Issue 002, dated July 9, 2024, or an upper fin assembly having a P/N that cannot be determined". Note 1 to paragraph (h)(1): MOD 0720098 involves installing a new upper fin that has a reinforced fin spar (P/N 355A14-0522-1751) that is not affected by this AD. Airbus Helicopters Alert Service Bulletin No. AS355-55.00.18, Revision 1, dated June 6, 2024, contains information regarding MOD 0720098. (2) Where EASA AD 2023-0154R1 refers to August 3, 2023 (the effective date of EASA AD 2023-0154, dated July 27, 2023), this AD requires using the effective date of this AD. (3) Where EASA AD 2023-0154R1 requires compliance in terms of flight hours, this AD requires using hours time-in-service. (4) Where paragraph (3) of EASA AD 2023-0154R1 specifies "following the Rotorcraft Flight Manual (RFM) amendment as required by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, it is allowed to exceed the temporary reduced Vne during a maintenance flight", this AD requires replacing that text with "following the Rotorcraft Flight Manual (RFM) amendment required by AD 2025-24-04, it is allowed to exceed the temporary reduced Velocity Never Exceed (V NE ) during a flight to perform an operational check as specified in 14 CFR 91.407". (5) Where paragraphs (3.1), (3.2), and (3.3) of EASA AD 2023-0154R1 specify "maintenance flight", this AD requires replacing that text with "flight to perform an operational check as specified in 14 CFR 91.407". (6) Where paragraph (4) of EASA AD 2023-0154R1 specifies "if, following the RFM amendment as required by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, the temporary reduced Vne is exceeded on a helicopter", this AD requires replacing that text with "if, following the RFM amendment required by AD 2025-24-04, the temporary reduced V NE is exceeded on a helicopter". (7) Where Note 1 of EASA AD 2023-0154R1 specifies "It is allowed to temporarily remove the RFM amendment and the placard, as required by paragraph (1) or (2) of EASA AD 2024-0139, as applicable, to allow maintenance flight(s) during which the temporarily reduced Vne may be exceeded", this AD requires replacing that text with "It is allowed to temporarily remove the RFM amendment and the placard required by AD 2025-24-04 to allow flight(s) to perform an operational check as specified in 14 CFR 91.407, during which the temporarily reduced V NE may be exceeded". Note 2 to paragraph (h)(7): Refer to AD 2025-24-04 for requirements pertaining to exceeding V NE 110 kts. Airbus Helicopters Emergency Alert Service Bulletin EASB AS355-05-00-0001, Issue 002, dated July 9, 2024, also contains information regarding exceeding V NE 110 kts. (8) Instead of complying with paragraph (6) of EASA AD 2023-0154R1, if there is a crack as a result of the inspections required by paragraphs (1) through (4) of EASA AD 2023-0154R1, this AD requires, before further flight, removing the upper fin from service and installing upper fin assembly P/N 355A14-0522-1751 in accordance with paragraph (7) and Note 2 of EASA AD 2023-0154R1. (9) Where Note 2 of EASA AD 2023-0154R1 specifies "paragraph (12) of EASA AD 2024-0139", this AD requires replacing that text with "AD 2025-24-04". (10) This AD does not adopt the "Remarks" section of EASA AD 2023-0154R1. (i) No Reporting Requirement Although the material referenced in EASA AD 2023-0154R1 specifies to submit certain information to the manufacturer, this AD does not include that requirement. (j) Special Flight Permits Special flight permits are prohibited. (k) Alternative Methods of Compliance (AMOCs) (1) The Manager, International Validation 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 local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, send it to the attention of the person identified in paragraph (l)(1) of this AD and email to: AMOC@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (l) Related Information (1) For more information about this AD, contact Yves Petiote, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (202) 975-4867; email: yves.petiote@faa.gov. (2) Airbus Helicopters material identified in this AD that is not incorporated by reference is available at Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-0000 or (800) 232-0323; fax: (972) 641-3775; website airbus.com/en/products-services/helicopters/hcare-services/airbusworld. (m) 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 2023-0154R1, dated July 19, 2024. (ii) [Reserved] (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find the EASA material on the EASA website at ad.easa.europa.eu. (4) You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. (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 fr.inspection@nara.gov. Issued on March 31, 2026. Christopher R. Parker, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-5039; 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. 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; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find the EASA material on the EASA website at ad.easa.europa.eu. - You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at regulations.gov under Docket No. FAA-2025-5039.

Yves Petiote, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (202) 975-4867; email: yves.petiote@faa.gov.