Airworthiness Directives; Airbus Helicopters

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1108; Project Identifier MCAI-2025-00428-R; Amendment 39-23140; AD 2025-18-13]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Airbus Helicopters</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is superseding Airworthiness Directive (AD) 2020-24-07 for certain Airbus Helicopters Model AS350B3, EC130B4, and EC130T2 helicopters. AD 2020-24-07 required modifying and inspecting the throttle twist grip (twist grip). Since the FAA issued AD 2020-24-07, there have been reports of the engine remaining in idle when the twist grip was turned to the “FLIGHT” mode. This AD retains the actions required by AD 2020-24-07 and adds a modification that constitutes terminating action for the repetitive inspections. This AD also expands the helicopter applicability, provides additional requirements for certain helicopters, and prohibits installing affected microswitches or an affected twist grip with the affected microswitch. The FAA is issuing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This AD is effective October 23, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 23, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD>   <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1108; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. <E T="03">Material Incorporated by Reference:</E> • For European Union Aviation Safety Agency (EASA) material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: <E T="03">ADs@easa.europa.eu;</E> website: <E T="03">easa.europa.eu</E> . You may find this material on the EASA website at <E T="03">ad.easa.europa.eu</E> . • 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. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1108. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Zain Jamal, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (847) 294-7264; email: <E T="03">zain.jamal@faa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2020-24-07, Amendment 39-21337 (85 FR 78954, December 8, 2020) (AD 2020-24-07). AD 2020-24-07 applied to Airbus Helicopters Model AS350B3 helicopters with an ARRIEL 2B1 engine with the two-channel Full Authority Digital Engine Control (FADEC) and with new twist grip modification (MOD) 073254 or with an ARRIEL 2D engine installed; Model EC130B4 helicopters with an ARRIEL 2B1 engine with the two-channel FADEC and with new twist grip MOD 073773 installed; and Model EC130T2 helicopters with an ARRIEL 2D engine installed. AD 2020-24-07 required repetitively inspecting the wiring, performing an insulation test, inspecting the pilot and copilot twist grip controls, and testing the pilot and copilot twist grip controls for proper functioning. The FAA issued AD 2020-24-07 to prevent the failure of one of the microswitches, 53Ka, 53Kb, or 65K, which can prevent switching from “IDLE” mode to “FLIGHT” mode during autorotation training making it impossible to recover from a practice autorotation and compelling the pilot to continue the autorotation to the ground. This condition could result in unintended touchdown to the ground at a flight-idle power setting during a practice autorotation, damage to the helicopter, and injury to occupants. The NPRM was published in the <E T="04">Federal Register</E> on June 20, 2025 (90 FR 26225). The NPRM was prompted by AD 2023-0133, dated July 5, 2023, issued by EASA, which is the Technical Agent for the Member States of the European Union (EASA AD 2023-0133). EASA AD 2023-0133 states that Airbus Helicopters developed MOD 074782, introducing a new engine power control assembly with microswitches 53Ka, 53Kb, and 65K, and mandating installation of a serviceable assembly, while prohibiting installation of an affected microswitch on any helicopter. EASA AD 2023-0133 also expands the applicability to all serial numbers of Airbus Helicopters Model AS 350 B3, EC 130 B4, and EC 130 T2 helicopters. EASA then superseded AD 2023-0133 and issued EASA AD 2023-0187, dated October 27, 2023 (EASA AD 2023-0187). EASA AD 2023-0187 states that errors were found in the modification installation procedure and requires amending the modification instructions and additional work for certain helicopters already modified. EASA then superseded AD 2023-0187 and issued EASA AD 2023-0187R1, dated March 20, 2025 (EASA AD 2023-0187R1) (also referred to as the MCAI), to correct an unsafe condition for all Airbus Helicopters Model AS 350 B3, EC 130 B4, and EC 130 T2 helicopters. The MCAI states that the salt-laden atmospheric condition definition should be re-formulated, adjusting to the less restrictive description provided in the applicable aircraft maintenance manual. The FAA did not issue an AD corresponding to EASA AD 2023-0133 and EASA AD 2023-0187. In the NPRM, the FAA proposed to retain the actions required by AD 2020-24-07 and mandate an additional modification, which would constitute terminating action for the repetitive inspections. In the NPRM, the FAA also proposed to expand the helicopter applicability, provide additional requirements for certain helicopters, and prohibit installation of affected microswitches or an affected twist grip with the affected microswitch. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1108. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received no comments on the NPRM or on the determination of the costs. <HD SOURCE="HD1">Conclusion</HD> 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. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed EASA AD 2023-0187R1, which specifies procedures for modifying the twist grip operational logic on helicopters with MOD 074263 installed. EASA AD 2023-0187R1 also specifies procedures for repetitively inspecting for no marks, residue, or corrosion and testing the “IDLE” and “FLIGHT” controls on the pilot's and copilot's twist grips on helicopters with MOD 074699 installed. Additionally, EASA AD 2023-0187R1 specifies procedures for installing MOD 074782 on helicopters if an affected microswitch is installed, which would constitute terminating action for the repetitive inspections. For those helicopters with MOD 074782 installed, EASA AD 2023-0187R1 specifies accomplishing a one-time inspection of the installation of the microswitch assembly of the engine power control. EASA AD 2023-0187R1 also prohibits installing a microswitch having a part number (P/N) T3933-3 or a twist grip containing a microswitch having P/N T3933-3 on any helicopter. This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the <E T="02">ADDRESSES</E> section. <HD SOURCE="HD1">Differences Between This AD and the MCAI</HD> The MCAI specifies the initial inspections within 10 flight hours or 7 days; this AD requires compliance before the next autorotation training flight, 100 hours time-in-service, or 6 months, whichever occurs first, as the unsafe condition only occurs when transitioning the throttle in-flight from flight to idle and back to flight, such as during a practice autorotation. Additionally, the MCAI specifies installing Airbus Helicopters MOD 074263; this AD does not require that modification as it would not correct the unsafe condition. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD affects 856 helicopters of U.S. registry. Labor costs are estimated at $85 per hour. Based on these numbers, the FAA estimates the following costs to comply with this AD. Inspecting the wiring, performing an insulation test, inspecting the pilot and copilot twist grip controls, and testing the pilot and copilot twist grip controls required by MOD 074699 takes about 4 work-hours, for an estimated cost of $340 per helicopter and $291,040 for the U ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 20k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━