Airworthiness Directives; Airbus Helicopters

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0617; Project Identifier MCAI-2024-00331-R; Amendment 39-23075; AD 2025-13-09]</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 adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, and SA-365N1 helicopters. This AD was prompted by reports of loss of tightening torque between the upper ball bearing end and the main rotor (MR) servo-control. This AD requires inspecting the tightening torque and, depending on the results, taking corrective action. This AD also requires reporting information. 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 August 14, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of August 14, 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-2025-0617; 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-2025-0617. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Peter Schmitt, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (206) 231-3377; email: <E T="03">peter.a.schmitt@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 by adding an AD that would apply to Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, and SA-365N1 helicopters. The NPRM was published in the <E T="04">Federal Register</E> on April 15, 2025 (90 FR 15667). The NPRM was prompted by EASA AD 2024-0110, dated June 6, 2024 (EASA AD 2024-0110) (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 two occurrences were reported of loss of tightening torque between the upper ball bearing end and the MR servo-control, which in one occurrence, led to the disconnection of these two parts. The MCAI further states that the investigation is still on-going to determine the root cause. EASA considers this MCAI an interim action and further action may follow. In the NPRM, the FAA proposed to require inspecting the tightening torque and, depending on the results, taking corrective action. Additionally, in the NPRM the FAA proposed to require reporting certain information. The FAA is issuing this AD to detect loss of tightening torque. The unsafe condition, if not addressed, could result in disconnection between the upper ball bearing end and the MR servo-control, and consequent loss of control of the helicopter. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0617. <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 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. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> EASA AD 2024-0110 requires a one-time check of the torque on each nut connecting the upper ball bearing end to all three MR servo-controls and, depending on the results, taking corrective actions, which include applying torque, lockwire, and sealing compound to the upper ball bearing end of the MR servo-control, inspecting the ball bearing end of the MR-servo control, replacing a ball bearing end, inspecting the upper end fitting of the MR-servo control, and replacing the MR servo-control. EASA AD 2024-0110 also requires reporting the inspection results (including no findings) to AH [Airbus Helicopters]. 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, as well as the material referenced in the MCAI, refer to the “torque inspection” as a “check.” In an FAA AD, a “check” may be done by the owner/operator (pilot) holding at least a private pilot certificate provided certain criteria are met. The authorization for a “check” in an FAA AD is an exception to the FAA's standard maintenance regulations and the criteria is not met in this AD. Accordingly, this AD requires those actions be accomplished by persons authorized under 14 CFR 43.3. <HD SOURCE="HD1">Interim Action</HD> The FAA considers that this AD is an interim action. If final action is later identified, the FAA might consider further rulemaking then. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD affects 63 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 tightening torque of the upper ball bearing end of each MR servo control will take 1 work-hour for an estimated cost of $255 per helicopter (three MR servo-controls per helicopter) and $16,065 for the U.S. fleet. Reporting the results of the inspection will take 1 work-hour for an estimated cost of $85 per helicopter and $5,355 for the U.S. fleet. If required, applying torque, lock-wire, and sealing compound to the upper ball bearing end of each MR servo-control will take .5 work-hour and parts will cost a nominal amount for an estimated cost of $127.50 per helicopter (for up to three MR servo-controls per helicopter). If required, inspecting the threads of a ball bearing end will take 1 work-hour for an estimated cost of $85 per ball bearing end. Depending on the results, replacing a ball bearing end will take 1 work-hour and parts will cost $1,299 for an estimated cost of $1,384 per ball bearing end. If required, inspecting the threads of an upper end fitting will take 1 work-hour for an estimated cost of $85 per upper-end fitting. Depending on the results, replacing an MR servo-control will take 1 work-hour and parts will cost $41,039 for an estimated cost of $41,124 per MR servo-control. <HD SOURCE="HD1">Paperwork Reduction Act</HD> A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to take approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524. <HD SOURCE="HD1">Authority for This Rulemaking</HD> 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 a ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 18k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━