2025-24-03: Main rotor drive system

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 2019-19-13, Amendment 39-19749 (84 FR 56109, October 21, 2019); and b. Adding the following new airworthiness directive: 2025-24-03 Airbus Helicopters: Amendment 39-23198; Docket No. FAA-2025-0909; Project Identifier MCAI-2023-00895-R. (a) Effective Date This airworthiness directive (AD) is effective December 26, 2025. (b) Affected ADs This AD replaces AD 2019-19-13, Amendment 39-19749 (84 FR 56109, October 21, 2019) (AD 2019-19-13). (c) Applicability This AD applies to Airbus Helicopters Model EC225LP helicopters, certificated in any category, with the parts identified in paragraphs (c)(1) or (2) of this AD installed, with "XX" denoting any dash number. (1) With a main rotor gearbox (MGB) part number (P/N) 332A32-5001-XX, 332A32-5002-XX, or 332A32-5003-XX, with a main reduction gear module (main module), with modification (MOD) 07-53016 (16-roller free wheel of free wheel shaft P/N 332A322191.20) installed, P/N 332A32-5011-XX, 332A32-5012-XX, or 332A32-5013-XX. (2) With an MGB P/N 332A32-5004-XX with a main module P/N 332A32-5400-00. (d) Subject Joint Aircraft System Component (JASC) Code 6320, Main rotor gear box; and 6300, Main rotor drive system. (e) Unsafe Condition This AD was prompted by a report of wear detected on the right-hand side (RH) free wheel shaft. In addition, since AD 2019-19-13 was issued, the FAA has determined that additional parts are affected by the same unsafe condition. The FAA is issuing this AD to prevent wear of the ramps of the right-hand side (RH) free wheel shaft. During an in-flight shutdown of the left-hand side engine, wear of the ramps of the RH free wheel shaft, if not addressed, could result in reduced ability to transfer one engine inoperative (OEI) power from the RH engine to the main rotor, and subsequent reduced control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) Within 10 hours time-in-service (TIS) after the effective date of this AD, determine the total hours TIS of the RH free wheel shaft since new or last RH free wheel shaft replacement during overhaul. (i) If the total hours TIS of the RH free wheel shaft is 1,000 or more hours TIS, before further flight, replace the MGB or replace the RH free wheel shaft. Thereafter, before any RH free wheel shaft accumulates 1,000 total hours TIS, replace the MGB or replace the RH free wheel shaft. (ii) If the total hours TIS of the RH free wheel shaft is less than 1,000 hours TIS, before exceeding 1,000 hours TIS, and thereafter before any RH free wheel shaft accumulates 1,000 total hours TIS, replace the MGB or replace the RH free wheel shaft. (2) Within 10 hours TIS after the effective date of this AD: (i) Install one or two self-adhesive placards on the instrument panel in full view of the pilot and co-pilot with 6-millimeter red letters on a white background that state the information contained in figure 1 to paragraph (g)(2)(i) of this AD. Note 1 to paragraph (g)(2)(i): Figure 4 of Airbus Helicopters Emergency Alert Service Bulletin No. EC225-04A016, Revision 4, dated June 19, 2023, shows an example of this placard. Figure 1 to Paragraph (g)(2)(i) ER20NO25.006 (ii) After installing the placard(s) required by paragraph (g)(2)(i) of this AD, before further flight, revise the limitations section of the existing rotorcraft flight manual (RFM) for the helicopter by adding the information in figure 2 to paragraph (g)(2)(ii) of this AD, by inserting a copy of this AD, or by making pen-and-ink changes. The owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM and must enter compliance with this RFM revision into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439. Figure 2 to Paragraph (g)(2)(ii) ER20NO25.007 (3) For Airbus Helicopters Model EC225LP helicopters with parts identified in paragraph (c)(1) of this AD installed, with "XX" denoting any dash number, as an optional terminating action for the requirements of this AD, install MGB P/N 332A32-5001-XX, 332A32-5002-XX, or 332A32-5003-XX, with a main module (12-roller free wheel), without MOD 07-53016 installed, P/N 332A32-5011-XX, 332A32-5012-XX, or 332A32-5013-XX. (h) Parts Installation Limitations As of the effective date of this AD, do not install the parts identified in paragraph (h)(1) or (2) of this AD, with "XX" denoting any dash number, on any helicopter unless the actions required by paragraph (g)(2) of this AD are accomplished. (1) MGB P/N 332A32-5001-XX, 332A32-5002-XX, or 332A32-5003-XX with a main module, with MOD 07-53016 (16-roller free wheel of free wheel shaft P/N 332A322191.20) installed, P/N 332A32-5011-XX, 332A32-5012-XX, or 332A32-5013-XX. (2) An MGB P/N 332A32-5004-XX with a main module P/N 332A32-5400-00. (i) Credit for Previous Actions This paragraph provides credit for the actions required by paragraphs (g)(1) and (2) of this AD, if those actions were performed before the effective date of this AD in accordance with the material identified in paragraphs (i)(1) through (3) of this AD. (1) Airbus Helicopters Emergency Alert Service Bulletin (ASB) No. EC225-04A016, Revision 1, dated June 28, 2019. (2) Airbus Helicopters Emergency ASB EC225-04A016, Revision 2, dated July 23, 2019. (3) Airbus Helicopters Emergency ASB EC225-04A016, Revision 3, dated August 5, 2019. (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: [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 (1) For more information about this AD, contact Frank Huynh, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (404) 983-2588; email: [email protected]. (2) For Airbus Helicopters material that is not incorporated by reference, 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. (l) Material Incorporated by Reference None. Issued on November 17, 2025. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2025-20482 Filed 11-19-25; 8:45 am]BILLING CODE 4910-13-P