Airworthiness Directives; Airbus Helicopters Deutschland GmbH Helicopters

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0630; Project Identifier MCAI-2023-00518-R; Amendment 39-23131; AD 2025-18-04]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Airbus Helicopters Deutschland GmbH 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 Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635T2+, MBB-BK 117 C-2, MBB-BK 117 D-2, and MBB-BK 117 D-3 helicopters. This AD was prompted by a review of design data and the determination for recalculation of accumulated hoist boom cycles (cycles) and repetitive inspections. This AD requires determining the total cycles of certain hoist boom assemblies, inspecting those hoist boom assemblies, and depending on the results, taking corrective action. This AD also prohibits installing those hoist boom assemblies unless certain requirements are met. 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 21, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publications listed in this AD as of October 21, 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-2025-0630; 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-2025-0630. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Steven Warwick, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5225; email: <E T="03">steven.r.warwick@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 Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635T2+, MBB-BK 117 C-2, MBB-BK 117 D-2, and MBB-BK 117 D-3 helicopters. The NPRM was published in the <E T="04">Federal Register</E> on April 25, 2025 (90 FR 17348). The NPRM was prompted by EASA AD 2023-0066, dated March 24, 2023 (EASA AD 2023-0066) (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 due to a review of design data, it was determined that hoist boom assemblies, part number (P/N) 44301-500, 44307-500, and 44307-500-1, must be inspected repetitively based on accumulated cycles. The additional inspection criteria were due to a new fatigue calculation to factor in external load, particularly human external cargo. In the NPRM, the FAA proposed to require determining the total cycles of certain hoist boom assemblies, inspecting those hoist boom assemblies, and depending on the results, taking corrective action. The FAA is issuing this AD to prevent failure of the hoist boom assembly. The unsafe condition, if not addressed, could lead to in-flight loss of the hoist load and consequent injury to occupants. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0630. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received one comment from Air Evac Lifeteam. The following presents the comment received on the NPRM and the FAA's response to the comment. Air Evac Lifeteam commented that the proposed AD lacks a compliance path for aircraft that do not have the affected part installed and requested the FAA revise the Applicability paragraph of the proposed AD to specify aircraft with the affected part installed. Air Evac Lifeteam alternatively suggested that the FAA add a compliance requirement for aircraft that do not have the affected part installed (Group 2 helicopters) that states that no further action is required. The applicability statement in each AD action identifies all aircraft affected by that AD. All of the requirements of an AD apply to the aircraft listed in the applicability, unless a specific paragraph in the AD specifies that it applies only to certain aircraft, such as those with an affected part installed. The MCAI that this AD incorporates by reference includes an installation limitation that currently applies to all models listed in the Applicability paragraph of this AD. If the Applicability paragraph of this AD were revised to apply only to those aircraft with the affected part installed, the installation limitation would only apply to aircraft with the affected part installed, rather than all aircraft. The FAA did not change this AD as a result of this comment. <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. 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 2023-0066, which specifies procedures for inspecting certain part-numbered hoist boom assemblies at certain intervals and, depending on the results, replacing or removing certain parts or taking further corrective action to resolve the discrepancy [crack, deformation, dent, corrosion, or other damage] or replacing the hoist boom assembly. EASA AD 2023-0066 also provides a terminating action for the inspections and prohibits installing those part-numbered hoist boom assemblies on any helicopter unless its requirements are met. 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 applies to Model EC635 P2+, EC635 P3, EC635 T1, EC635 T3, and MBB-BK117 D-3m helicopters, whereas this AD does not because these model helicopters do not have an FAA type certificate. The MCAI requires accomplishing a corrective action in accordance with the instructions of the service material, whereas this AD requires repairing or replacing affected parts that have certain discrepancies, within allowable limits, as described in this AD. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD affects 732 helicopters of U.S. registry. Labor rates are estimated at $85 per hour. Based on these numbers, the FAA estimates the following costs to comply with this AD. If required, determining the total cycles will take 0.5 work-hour for an estimated cost of $43 per helicopter. Inspecting a hoist boom assembly will take 4 work-hours for an estimated cost of $340 per helicopter and $248,880 for the U.S. fleet, per inspection cycle. Repairing any surface deformation, damage, or corrosion that is within allowable limits will take up to 1 work-hour and parts will cost a nominal amount for an estimated cost of up to $85 per helicopter. Replacing a hoist boom assembly (which includes a boom elbow, boom tube, and boom adapter) will take up to 5 work-hours (depending on configuration) and parts will cost up to $88,812 (depending on P/N) for an estimated cost of up to $89,237 per helicopter. <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 aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. 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