Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2019-19-13, Amendment 39-19749 (84 FR 56109, October 21, 2019) (AD 2019-19-13). AD 2019-19-13 applied to Airbus Helicopters Model EC225LP helicopters, with a MGB part number (P/N) 332A325001.XX, 332A325002.XX, or 332A325003.XX, with a main reduction gear module (main module), and with a certain modification installed. The NPRM was published in the Federal Register on May 22, 2025 (90 FR 21871). The NPRM was prompted by European Union Aviation Safety Agency (EASA) AD 2023-0148, dated July 19, 2023 (EASA AD 2023-0148) (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 since a previous EASA AD was issued, it was determined that an additional part-numbered MGB is potentially affected by the same unsafe condition and expanded the affected parts by adding MGB P/N 332A32-5004-00 with main module P/N 332A32-5400-00 installed. In the NPRM, the FAA determined that repetitive replacement of the MGB is necessary and proposed requiring repetitive replacement of the MGB or the RH free wheel shaft at the 1,000 total hours TIS threshold. In the NPRM, the FAA proposed updating the actions that require replacing certain parts under the supervision of a qualified Airbus Helicopter Specialist by removing the requirement for the specified specialist since the actions must be accomplished by persons authorized under 14 CFR 43.3. In the NPRM, the FAA also proposed to change the information that specifies availability of an example of the placard required by the proposed AD. Additionally, in the NRPM the FAA proposed to expand the parts installation limitation conditions and used an updated format; as a result, paragraph identifiers have changed. In the NPRM, the FAA proposed to remove the requirement to determine the total hours TIS of the left-hand (LH) free wheel shaft. Finally, in the NPRM, the FAA proposed to require revising the existing RFM for the helicopter. Revising the existing RFM for the helicopter may be performed by the owner/operator (pilot) holding at least a private pilot certificate and must be entered into the aircraft records showing compliance with this action in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot may perform this action because it only involves revising the existing RFM by inserting pages, which is not considered a maintenance action. The FAA is issuing this AD to prevent wear of the ramps of the 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. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-0909. Discussion of Final Airworthiness Directive Comments The FAA received no comments on the NPRM or on the determination of the costs. 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. Differences Between This AD and the MCAI This AD requires revising the existing RFM for the helicopter, whereas the MCAI does not. The MCAI requires reporting information, whereas this AD does not. Interim Action The FAA considers that this AD is an interim action. If final action is later identified, the FAA might consider further rulemaking. Costs of Compliance The FAA estimates that this AD will affect 28 helicopters of U.S. registry. The FAA estimates the following costs to comply with this AD. Labor costs are estimated at $85 per hour. Determining the total hours TIS of each free wheel shaft will take 0.25 work-hour, for an estimated cost of $21 per helicopter and $588 for the U.S. fleet. Installing placard(s) and revising the existing RFM for the helicopter will take 0.5 work-hour for an estimated cost of $43 per helicopter and $1,204 for the U.S. fleet. Replacing an MGB will take 40 work-hours and parts will cost $850,000 (overhauled), for an estimated cost of $853,400 per helicopter, per replacement cycle. Alternatively, replacing the RH free wheel shaft will take 4 work-hours and parts will cost $24,021, for an estimated cost of $24,361 per helicopter, per replacement cycle. 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 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: 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 Frank Huynh, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (404) 983-2588; email: frank.huynh@faa.gov. (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.