2026-21-10: Tail rotor gearbox

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: 2026-21-10 Airbus Helicopters: Amendment 39-23499; Docket No. FAA-2026-11815; Project Identifier MCAI-2026-00154-R. (a) Effective Date This airworthiness directive (AD) is effective November 12, 2026. (b) Affected ADs None. (c) Applicability This AD applies to all Airbus Helicopters SA 365 N helicopters, certified in any category. (d) Subject Joint Aircraft System Component (JASC) Code 6520, Tail rotor gearbox. (e) Unsafe Condition This AD was prompted by reports of tightening torque loss on the input flange nut due to circular wear on the faces of the flange, the slip ring, and the input flange. This condition, if not addressed, could lead to degradation or jamming of the input roller bearings and loss of yaw 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 2026-0029, dated February 12, 2026 (EASA AD 2026-0029). (h) Exceptions (1) Where EASA AD 2026-0029 refers to its effective date, this AD requires the effective date of this AD. (2) Where EASA AD 2026-0029 requires compliance in terms of flight hours, this AD requires using hours time-in-service. (3) Where EASA AD 2026-0029 or the material referenced in EASA AD 2026-0029 specifies "check", this AD requires replacing that text with "inspection". (4) Where EASA AD 2026-0029 and the material referenced in EASA AD 2026-0029 specify to contact the manufacturer if the comparator gauge confirms a value more than or equal to 0.03 mm, or after completing an oil sample analysis, this AD requires corrective actions in accordance with a method approved by the Manager, International Validation Branch, FAA; EASA; or Airbus Helicopters Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature. (i) No Reporting Requirement Although the material referenced in EASA AD 2026-0029 specifies to submit certain information to the manufacturer, this AD does not require that action. (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) of this AD and email to [email protected]. (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 For more information about this AD, contact Anthony Kenward, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5257; email: [email protected]. (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) 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) European Union Aviation Safety Agency (EASA) EASA AD 2026-0029, dated February 12, 2026. (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: [email protected]; 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, 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 [email protected] . Issued on October 19, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-21854 Filed 10-26-26; 8:45 am]BILLING CODE 4910-13-P