2025-06-04: Main 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: 2025-06-04 Airbus Helicopters: Amendment 39-22992; Docket No. FAA-2024-2419; Project Identifier MCAI-2023-00366-R. (a) Effective Date This airworthiness directive (AD) is effective May 9, 2025. (b) Affected ADs None. (c) Applicability This AD applies to all Airbus Helicopters Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code: 6320, Main Rotor Gearbox. (e) Unsafe Condition This AD was prompted by an assessment performed by the manufacturer which determined that additional actions are necessary to improve particle detection for main gearboxes (MGBs) with certain part-numbered planet gear bearings installed. The FAA is issuing this AD to detect and correct particles in the MGB. The unsafe condition, if not addressed, could result in reduced or loss of 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 AD 2023-0044, dated February 28, 2023 (EASA AD 2023-0044). (h) Exceptions to EASA AD 2023-0044 (1) Where EASA AD 2023-0044 defines "serviceable MGB" as "An affected MGB which has accumulated less than 330 flight hours (FH) since new (first installation on a helicopter), or since an overhaul, or since an inspection in accordance with the instructions of the ASB," this AD requires replacing that text with "An affected MGB which has accumulated less than 330 total hours time-in-service since new (zero total hours time-in-service), since last overhaul if an overhaul has been accomplished, or since last inspection and any specified corrective action in accordance with the instructions of the ASB if an inspection and any specified corrective action by following the instructions of the ASB have been accomplished." (2) Where EASA AD 2023-0044 requires compliance in terms of flight hours, this AD requires using hours time-in-service (TIS). (3) Where EASA AD 2023-0044 refers to its effective date, this AD requires using the effective date of this AD. (4) Where Note 1 in the material referenced in paragraph (1) of EASA AD 2023-0044 specifies the option of 1 mechanical technician and 1 crew member, for this AD, the pilot is only permitted to turn the tail rotor (b). The owner/operator (pilot) holding at least a private pilot certificate may turn the tail rotor (b) and must enter compliance with paragraph (g) of this AD in the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.43. All other actions specified in Note 1 in the material referenced in paragraph (1) of EASA AD 2023-0044 must be accomplished by persons authorized under 14 CFR 43.3. (5) Where Note 2 in the material referenced in paragraph (1) of EASA AD 2023-0044 specifies contacting Airbus Helicopters for further instructions if the bottom of the radius (a6) of the bevel wheel (a3) or head screws (a4) (see Figure 2) are not clearly visible, this AD requires, before further flight, accomplishing action in accordance with a method approved by the FAA, EASA, or Airbus Helicopters' EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature. (6) Instead of complying with paragraph (2) of EASA AD 2023-0044, comply with the actions required by paragraphs (h)(6)(i) and (ii) of this AD. (i) After the effective date of this AD, and within the compliance time intervals specified table 1 to paragraph (h)(6)(i) of this AD, visually inspect the MGB magnetic plug for particles. Note 1 to paragraph (h)(6)(i): Aircraft Maintenance Manual (AMM) task 60-00-00, 6-2A, or AMM task 60-00-00, 6-2, or work card 60-00-00-602, as applicable, provides information regarding inspecting the MGB magnetic plug. Table 1 to Paragraph ( h )(6)( i )-MGB Magnetic Plug Inspections Helicopter model(s) Initial compliance times (after the effective date of this AD) (hours TIS) Interval compliance times (thereafter) (hours TIS) AS350B, AS350B1, AS350BA, and AS350D 5 30 AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP 5 30 AS350B2 and AS350B3 10 100 EC130B4 5 150 EC130T2 5 150 (ii) If there is any particle as a result of any MGB magnetic plug inspection required by paragraph (h)(6)(i) of this AD, before further flight, borescope inspect the bevel wheel of the affected MGB for particles as required by paragraph (1) of EASA AD 2023-0044. If there is any particle as a result of the borescope inspection of the bevel wheel, before further flight, collect and analyze the particles as required by paragraph (3) of EASA AD 2023-0044. (7) Where paragraph (3) of EASA AD 2023-0044 specifies "If, during any inspection as required by paragraph (1) or (2) of this AD," this AD requires replacing that text with "If, during any inspection as required by paragraph (1) of this AD." (8) Where the material referenced in paragraph (3) of EASA AD 2023-0044 specifies performing a metallurgical analysis and contacting Airbus Helicopters if collected particles cannot be characterized with Work Card 20-08-01-601, this AD does not require contacting Airbus Helicopter but does require performing the metallurgical analysis. (9) This AD does not allow the ferry flight provision specified in the material referenced in paragraph (3) of EASA AD 2023-0044; for this AD, refer to paragraph (j) of this AD. (10) Where the material referenced in paragraph (3) of EASA AD 2023-0044 specifies contacting Airbus Helicopters if the damaged module cannot be identified, this AD requires, before further flight, accomplishing action in accordance with a method approved by the FAA, EASA, or Airbus Helicopters' EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature. (11) Where paragraph (5) of EASA AD 2023-0044 states "to contact AH for corrective action(s) instructions, and within the compliance time specified therein, to accomplish those instructions accordingly," this AD requires replacing that text with "accomplishing corrective actions in accordance with a method approved by the FAA, EASA, or Airbus Helicopters' EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature." (12) Where paragraph (7) of EASA AD 2023-0044 states "since new (first installation a helicopter), or since an overhaul, or since an inspection in accordance with the instructions of the ASB, as applicable, and, thereafter, as required by this AD," this AD requires replacing that text with "since new (zero total hours time-in-service), or since last overhaul if an overhaul has been accomplished, or since last inspection and any specified corrective action in accordance with the instructions of the ASB if an inspection and any specified corrective action by following the instructions of the ASB have been accomplished, and thereafter as required by this AD." (13) This AD does not adopt the "Remarks" section of EASA AD 2023-0044. (i) No Reporting Requirement Although the material referenced in EASA AD 2023-0044 specifies to submit certain information to the manufacturer, this AD does not require that action. (j) Special Flight Permits A special flight permit may be issued in accordance with 14 CFR 21.197 and 21.199 to permit a one-time, non-revenue flight to a location where the actions required by this AD can be accomplished. This flight must be performed with only essential flight crew. (k) 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 (l) of this AD. Information may be emailed to: 9-AVS-AIR-730-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. (l) Related Information For more information about this AD, contact Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (404) 474-5548; email: william.mccully@faa.gov. (m) 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) European Union Aviation Safety Agency (EASA) AD 2023-0044, dated February 28, 2023. (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: ADs@easa.europa.eu; 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, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, 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 March 28, 2025. Paul R. Bernado, Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2025-05781 Filed 4-3-25; 8:45 am]BILLING CODE 4910-13-P