2026-09-15: Tail rotor head

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