AD 2026-09-15 ACTIVE

The FAA is superseding Airworthiness Directive (AD) 2023-01-04 for all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. AD 2023-01-04 required, for helicopters with certain part- numbered tail rotor head (TRH) spider pitch change units installed, inspecting the pitch change spider nut (nut) for correct installation; marking a 2 to 5 mm wide black paint index mark and repetitively inspecting the alignment of the marking; and performing additional inspections and corrective actions if necessary. Since the FAA issued AD 2023-01-04, new or more restrictive airworthiness limitations were issued, which terminated the requirement for the repetitive inspections of the black paint index marking. This AD requires the same actions as AD 2023-01-04, except for the repetitive black paint index marking inspections and prohibits installing certain parts unless certain requirements are met. 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: a. Removing Airworthiness Directive 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023); and b. Adding the following new airworthiness directive: 2026-09-15 Airbus Helicopters: Amendment 39-23337; Docket No. FAA-2025-5387; Project Identifier MCAI-2024-00399-R. (a) Effective Date This airworthiness directive (AD) is effective July 21, 2026. (b) Affected ADs This AD replaces AD 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023). (c) Applicability This AD applies to all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters, certificated in any category. Note 1 to paragraph (c): Helicopters with AS350B3e designation are Model AS350B3 helicopters. (d) Subject Joint Aircraft System Component (JASC) Code 6420, Tail rotor head. (e) Unsafe Condition This AD was prompted by an occurrence reported where, during an inspection of a tail rotor head (TRH) pitch change unit, excessive play and excessive wear were detected, due to an unwanted rotating motion and updated airworthiness limitations and maintenance tasks. The FAA is issuing this AD to detect improper installation of the pitch change spider nut (nut) and improper alignment of a black index marking. The unsafe condition, if not addressed, could result in loss of the TRH pitch change control and consequent loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) For helicopters with TRH pitch change unit, part number (P/N) 350A33-2030-00, 350A33-2167-00, or 350A33-2167-01 installed, within 50 hours time-in-service (TIS) after the effective date of this AD, inspect the nut for correct installation. If the nut is missing or loose, before further flight, remove the bearing from the TRH pitch change unit and do the following: (i) Inspect the TRH pitch change unit for corrosion. If there is any corrosion, before further flight, remove the affected part from service and replace with an airworthy part. Note 2 to paragraph (g)(1)(i): Airbus Helicopters Mechanical Repair Manual (MRM) AS350 65-20-00-713, dated March 29, 2017, also known as Work Card 65-20-00-713 MRM, and Airbus Aircraft Maintenance Manual (AMM) AS350 65-21-00, 4-9b, dated May 16, 2019, also known as Task 65-21-00, 4-9 AMM, specify disassembly and reassembly information for the TRH pitch change unit. (ii) Inspect for rotation and wear on the faces of the bushes. For the purposes of this AD, indications of rotation and wear include tearing, peening, metal pick-up, and hammering. If there is any rotation or any wear on the faces of the bushes, before further flight, remove the bushes from service and replace with airworthy bushes. (iii) Using 5X or higher power magnification, visually inspect the rotating plate and the rotating plate threads for damage. For the purposes of this AD, indications of damage include wear, deformation, stripping, galling, and corrosion. If there is any damage on the rotating plate or the rotating plate threads, before further flight, remove the rotating plate from service and replace with an airworthy rotating plate. (iv) Identify the position of the TRH pitch change unit (item a) and of bearing spacer (item b) by marking a 2 to 5 mm wide black paint index mark (item C) with black paint as depicted in Figure 1, Section B-B, of Airbus Helicopters Alert Service Bulletin (ASB) No. AS350-05.01.03, (ASB AS350-05.01.03 Rev 1), or Airbus Helicopters ASB No. AS355-05.00.86 (ASB AS355-05.00.86 Rev 1), both Revision 1, and dated July 8, 2024, as applicable to the model helicopter. (2) Within 10 hours TIS after the initial marking required by paragraph (g)(1)(iv) of this AD, visually inspect the alignment of the marking. An example of a properly aligned marking is depicted in Figure 1, Section B-B of ASB AS350-05.01.03 Rev 1 and ASB AS355-05.00.86 Rev 1, as applicable to the model helicopter. If the black paint index mark (item C) is misaligned, before further flight, inspect the TRH pitch change unit by accomplishing the actions required by paragraphs (g)(1)(i) and (ii) of this AD. (h) Parts Installation Limitations As of the effective date of this AD, do not install a TRH pitch change unit P/N 350A33-2030-00, 350A33-2167-00, or 350A33-2167-01 on any helicopter, unless you do the actions required by paragraphs (g)(1)(i) through (iv) of this AD before further flight after installation, and thereafter do the actions required by paragraph (g)(2) of this AD at the times specified in paragraph (g)(2) of this AD. (i) Credit for Previous Actions This paragraph provides credit for the initial inspections and actions required by paragraph (g)(1) of this AD, if those actions were performed before the effective date of this AD using Airbus Helicopters ASB No. AS350-05.01.03, or ASB No. AS355-05.00.86, both Revision 0, and dated December 16, 2021. (j) 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 (k)(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. (k) Additional Information (1) For more information about this AD, contact Matthew Williams, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4134; email: matthew.t.williams@faa.gov. (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) Airbus Helicopters Alert Service Bulletin (ASB) No. AS350-05.01.03, Revision 1, dated July 8, 2024. (ii) Airbus Helicopters ASB No. AS355-05.00.86 Revision 1, dated July 8, 2024. (3) For Airbus Helicopters material identified in this AD, contact 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. (4) You may view this material at the FAA, Office of the Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, 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 June 11, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-12048 Filed 6-15-26; 8:45 am]BILLING CODE 4910-13-P

Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023), (AD 2023-01-04). AD 2023-01-04 applied to Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. AD 2023-01-04 required, for helicopters with certain part-numbered TRH spider pitch change units installed, inspecting for correct installation of the nut; marking a 2 to 5 mm wide black paint index mark to identify the position of certain parts; and after the initial marking, repetitively inspecting the alignment of the marking; and additional inspections and corrective actions if necessary. Additionally, AD 2023-01-04 prohibited installing an affected part on a helicopter unless certain requirements were met. The FAA issued AD 2023-01-04 to detect improper installation of the nut and improper alignment of a black index marking. The NPRM was published in the Federal Register on December 17, 2025 (90 FR 58512). The NPRM was prompted by European Union Aviation Safety Agency (EASA) AD 2021-0282R1, Revision 1, dated July 10, 2024 (EASA AD 2021-0282R1) (also referred to as the MCAI), issued by EASA, which is the Technical Agent for the Member States of the European Union. The MCAI states that the manufacturer revised the Airworthiness Limitations Section (ALS), as applicable, which now includes the repetitive black index marking checks (inspections). In the NPRM, the FAA proposed to require the same actions as AD 2023-01-04, except the NPRM only proposed to require the initial black paint index marking inspection, not the repetitive inspections. The FAA also proposed to prohibit installing an affected part on a helicopter unless certain requirements are met. You may examine the AD docket at regulations.gov under Docket No. FAA-2025-5387. Discussion of Final Airworthiness Directive Comments The FAA received a comment from an individual commenter. The following presents the comment received on the NPRM and the FAA's response to the comment. Request To Clarify Black Paint Index Mark Visual Inspection for New Units The commenter requested that the FAA add language to paragraph (g)(2) of the proposed AD to clarify whether a 10 hour time-in-service visual inspection of the black paint index mark is required on a pitch change unit that is new or newly overhauled. The FAA disagrees with the request to update paragraph (g)(2) of this AD but agrees to clarify that the repetitive black paint index mark visual inspections are now integrated into the ALS for affected part numbers 350A33-2030-00, 350A33-2167-00, and 350A33-2167-01, in accordance with the applicable ALS. No changes were made to this AD as a result of this comment. 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 and technical corrections in paragraph (h) to accurately reflect the parts installation limitations, 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 Airbus Helicopters Alert Service Bulletin (ASB) No. AS350-05.01.03, and Airbus Helicopters ASB No. AS355-05.00.86, both Revision 1 and dated July 8, 2024, which include Figure 1 that identifies the position of the TRH pitch change unit and of the bearing spacer to be marked with a 2 to 5 mm wide black paint index mark. This material also specifies procedures for inspecting the condition and installation of the nut; and inspecting the application and alignment of the black index mark on the TRH pitch change unit and the bearing spacer. 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 The MCAI applies to Airbus Helicopters Model AS350BB, whereas this AD does not because that model does not have an FAA type certificate. Costs of Compliance The FAA estimates that this AD affects 972 helicopters of U.S. registry. The FAA estimates the following costs to comply with this AD. Estimated Costs Action Labor cost Parts cost Cost per product Cost on U.S. operators Inspect the nut 1 work-hour × $85 per hour = $85 $0 $85 $82,620 Inspect alignment of marking 1 work-hour × $85 per hour = $85 0 85 82,620 Place black paint marking 1 work-hour × $85 per hour = $85 0 85 82,620 The FAA estimates the following costs to do any repairs/replacements that would be required based on the results of the inspection. The agency has no way of determining the number of helicopters that might need these repairs or replacements: On-Condition Costs Action Labor cost Parts cost Cost per product Inspect the TRH pitch change unit 13 work-hours × $85 per hour = $1,105 $0 $1,105. Replace bushes 1 work-hour × $85 per hour = $85 5,918 6,003 per helicopter. Replace a rotating plate 1 work-hour × $85 per hour = $85 27,375 27,460 per helicopter. 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 The FAA has determined that 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: a. Removing Airworthiness Directive 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023); and b. Adding the following new airworthiness directive: 2026-09-15 Airbus Helicopters: Amendment 39-23337; Docket No. FAA-2025-5387; Project Identifier MCAI-2024-00399-R. (a) Effective Date This airworthiness directive (AD) is effective July 21, 2026. (b) Affected ADs This AD replaces AD 2023-01-04, Amendment 39-22298 (88 FR 6618, February 1, 2023). (c) Applicability This AD applies to all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters, certificated in any category. Note 1 to paragraph (c): Helicopters with AS350B3e designation are Model AS350B3 helicopters. (d) Subject Joint Aircraft System Component (JASC) Code 6420, Tail rotor head. (e) Unsafe Condition This AD was prompted by an occurrence reported where, during an inspection of a tail rotor head (TRH) pitch change unit, excessive play and excessive wear were detected, due to an unwanted rotating motion and updated airworthiness limitations and maintenance tasks. The FAA is issuing this AD to detect improper installation of the pitch change spider nut (nut) and improper alignment of a black index marking. The unsafe condition, if not addressed, could result in loss of the TRH pitch change control and consequent loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) For helicopters with TRH pitch change unit, part number (P/N) 350A33-2030-00, 350A33-2167-00, or 350A33-2167-01 installed, within 50 hours time-in-service (TIS) after the effective date of this AD, inspect the nut for correct installation. If the nut is missing or loose, before further flight, remove the bearing from the TRH pitch change unit and do the following: (i) Inspect the TRH pitch change unit for corrosion. If there is any corrosion, before further flight, remove the affected part from service and replace with an airworthy part. Note 2 to paragraph (g)(1)(i): Airbus Helicopters Mechanical Repair Manual (MRM) AS350 65-20-00-713, dated March 29, 2017, also known as Work Card 65-20-00-713 MRM, and Airbus Aircraft Maintenance Manual (AMM) AS350 65-21-00, 4-9b, dated May 16, 2019, also known as Task 65-21-00, 4-9 AMM, specify disassembly and reassembly information for the TRH pitch change unit. (ii) Inspect for rotation and wear on the faces of the bushes. For the purposes of this AD, indications of rotation and wear include tearing, peening, metal pick-up, and hammering. If there is any rotation or any wear on the faces of the bushes, before further flight, remove the bushes from service and replace with airworthy bushes. (iii) Using 5X or higher power magnification, visually inspect the rotating plate and the rotating plate threads for damage. For the purposes of this AD, indications of damage include wear, deformation, stripping, galling, and corrosion. If there is any damage on the rotating plate or the rotating plate threads, before further flight, remove the rotating plate from service and replace with an airworthy rotating plate. (iv) Identify the position of the TRH pitch change unit (item a) and of bearing spacer (item b) by marking a 2 to 5 mm wide black paint index mark (item C) with black paint as depicted in Figure 1, Section B-B, of Airbus Helicopters Alert Service Bulletin (ASB) No. AS350-05.01.03, (ASB AS350-05.01.03 Rev 1), or Airbus Helicopters ASB No. AS355-05.00.86 (ASB AS355-05.00.86 Rev 1), both Revision 1, and dated July 8, 2024, as applicable to the model helicopter. (2) Within 10 hours TIS after the initial marking required by paragraph (g)(1)(iv) of this AD, visually inspect the alignment of the marking. An example of a properly aligned marking is depicted in Figure 1, Section B-B of ASB AS350-05.01.03 Rev 1 and ASB AS355-05.00.86 Rev 1, as applicable to the model helicopter. If the black paint index mark (item C) is misaligned, before further flight, inspect the TRH pitch change unit by accomplishing the actions required by paragraphs (g)(1)(i) and (ii) of this AD. (h) Parts Installation Limitations As of the effective date of this AD, do not install a TRH pitch change unit P/N 350A33-2030-00, 350A33-2167-00, or 350A33-2167-01 on any helicopter, unless you do the actions required by paragraphs (g)(1)(i) through (iv) of this AD before further flight after installation, and thereafter do the actions required by paragraph (g)(2) of this AD at the times specified in paragraph (g)(2) of this AD. (i) Credit for Previous Actions This paragraph provides credit for the initial inspections and actions required by paragraph (g)(1) of this AD, if those actions were performed before the effective date of this AD using Airbus Helicopters ASB No. AS350-05.01.03, or ASB No. AS355-05.00.86, both Revision 0, and dated December 16, 2021. (j) 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 (k)(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. (k) Additional Information (1) For more information about this AD, contact Matthew Williams, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4134; email: matthew.t.williams@faa.gov. (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) Airbus Helicopters Alert Service Bulletin (ASB) No. AS350-05.01.03, Revision 1, dated July 8, 2024. (ii) Airbus Helicopters ASB No. AS355-05.00.86 Revision 1, dated July 8, 2024. (3) For Airbus Helicopters material identified in this AD, contact 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. (4) You may view this material at the FAA, Office of the Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, 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 June 11, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-5387; 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 Airbus Helicopters material identified in this AD, contact 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. - You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, 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-2025-5387.

Matthew Williams, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4134; email: matthew.t.williams@faa.gov .