Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2020-09-15, Amendment 39-19911 (85 FR 30589, May 20, 2020), (AD 2020-09-15). AD 2020-09-15 applied to Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters, equipped with a dual hoist installation and de-icing system, except those that have Airbus Helicopters modification 0722907 installed in production. AD 2020-09-15 required removing the removable parts of the dual hoist installation or removing the de-icing system and allows, for certain helicopters, revising the RFM for the helicopter and installing a placard as an optional method of compliance. The FAA issued AD 2020-09-15 to prevent divergent aeromechanic coupling between the helicopter structure and rotor. The unsafe condition, if not addressed, could generate divergent aeromechanic coupling between the helicopter structure and the rotor, possibly resulting in mechanical failure of structural parts and loss of control of the helicopter. The NPRM was published in the Federal Register on December 17, 2025 (90 FR 58515). The NPRM was prompted by European Union Aviation Safety Agency (EASA) AD 2024-0233, dated December 5, 2024 (EASA AD 2024-0233) (also referred to as the MCAI). The MCAI was issued by EASA, which is the Technical Agent for the Member States of the European Union. The MCAI states it was determined that further vibration level measurements were necessary after performing certain maintenance tasks. The MCAI further states that EASA AD 2024-0233 is considered to be an interim action. In the NPRM, the FAA proposed to retain all the requirements of AD 2020-09-15 and also proposed to require repetitively measuring the vibration level, interpreting the results, and depending on the results, removing certain parts and further inspections. In the NPRM the FAA also proposed to allow an alternative to removing parts by placing a placard and revising the RFM for the helicopter. Additionally, in the NPRM the FAA proposed to prohibit installing the de-icing system and the dual hoist unless certain requirements are accomplished. In the NPRM the FAA specifies measuring the vibration levels in-flight and 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 these actions because they only involve recording data in-flight and revising the existing RFM by inserting pages, which are not considered maintenance actions. 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. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Airbus Helicopters Alert Service Bulletin ASB AS332-04-00-0001, Issue 002, dated December 4, 2024 (ASB AS332-04-00-0001), which specifies procedures for installing the accelerometer in the cockpit of the helicopter, repetitively inspecting the vibration level at 12 Hz each time a specific maintenance task is completed, and interpreting the results. Depending on the results of this inspection, ASB AS332-04-00-0001 specifies procedures for corrective actions, which include changing the configuration by either removing the dual hoist system or removing the de-icing harness and contacting Airbus Helicopters for further instructions. The FAA also reviewed Airbus Helicopters Emergency Alert Service Bulletin (EASB) AS332 01.00.91, Revision 1, dated December 4, 2019 (EASB 01.00.91 Rev 1) for Model AS332C, and AS332C1 helicopters, and EASB AS332 01.00.96, Revision 0, dated December 4, 2019 (EASB 01.00.96) for Model AS332L and AS332L1 helicopters. EASB 01.00.91 Rev 1 specifies procedures for removing parts of the dual hoist installation or removing the de-icing system. EASB 01.00.96 describes procedures for amending the RFM of Airbus Helicopters Model AS332L and AS332L1 helicopters to limit the flight envelope and the Vne and installing a placard. EASB 01.00.96 also describes procedures for removing parts of the dual hoist installation or removing the de-icing system. The Director of the Federal Register approved EASB 01.00.91 Rev 1 and EASB 01.00.96 for incorporation by reference as of May 20, 2020 (85 FR 30589, May 20, 2020). 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 ADDRESSES section. Interim Action The FAA considers this AD as an interim action. If final action is later identified, the FAA might consider further rulemaking. Costs of Compliance The FAA estimates that this AD affects five helicopters of U.S. registry. The FAA estimates the following costs to comply with this AD. Estimated Costs Action Labor cost Parts cost Cost per product Cost on U.S. operators Remove the removable parts of the dual hoist 12 work-hours × $85 per hour = $1,020 per helicopter $0 $1,020 $5,100 Remove the de-icing system 12 work-hours × $85 per hour = $1,020 per helicopter 0 $1,020 5,100 Measure vibrations to include interpreting results 7 work-hours × $85 per hour = $595 0 $595 per cycle 2,975 The FAA estimates the following costs to do any actions that would be required based on the results of the inspection. The agency has no way of determining the number of helicopters that might need these repairs or replacements: On-Condition Costs Action Labor cost Parts cost Cost per product Revise the RFM 1 work-hour × $85 per hour = $85 $0 $85 Install a placard 1 work-hour × $85 per hour = $85 0 85 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 2020-09-15, Amendment 39-19911 (85 FR 30589, May 20, 2020); and b. Adding the following new airworthiness directive: 2026-05-11 Airbus Helicopters: Amendment 39-23284; Docket No. FAA-2025-5389; Project Identifier MCAI-2024-00716-R. (a) Effective Date This airworthiness directive (AD) is effective April 17, 2026. (b) Affected ADs This AD replaces AD 2020-09-15, Amendment 39-19911 (85 FR 30589, May 20, 2020) (AD 2020-09-15). (c) Applicability This AD applies to Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters, certificated in any category, equipped with a dual hoist installation and de-icing system. (d) Subject Joint Aircraft System Component (JASC) Code 1810, Helicopter vibration analysis. (e) Unsafe Condition This AD was prompted by a report of vibrations around the 12 Hz frequency due to the specific helicopter configuration and determination that additional vibration level measurements are necessary. The FAA is issuing this AD to prevent divergent aeromechanic coupling between the helicopter structure and rotor. The unsafe condition, if not addressed, could result in mechanical failure of structural parts and consequent loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) For helicopters without Airbus Helicopters modification 0722907 installed, within 7 days after May 20, 2020 (the effective date of AD 2020-09-15): Remove the removable parts of the dual hoist installation or remove the de-icing system in accordance with the instructions of section 3.B of Airbus Helicopters Emergency Alert Service Bulletin (EASB) AS332 01.00.91, Revision 1, dated December 4, 2019 (EASB AS332 01.00.91 Rev 1), or Section 3.B.2 of Airbus Helicopters EASB AS332 01.00.96, Revision 0, dated December 4, 2019 (EASB AS332 01.00.96), as applicable to the helicopter, except you are not required to contact Airbus Helicopters. (2) For helicopters with Airbus Helicopters modification 0722907 installed, within 110 hours time-in-service (TIS) or 30 days whichever occurs first after the effective date of this AD and thereafter, during the first flight after each time any of the maintenance tasks identified in the COMPLIANCE: MANDATORY section of Airbus Helicopters Alert Service Bulletin ASB AS332-04-00-0001, Issue 002, dated December 4, 2024 (ASB AS332-04-00-0001) is accomplished, perform a vibration level measurement in accordance with paragraphs (g)(2)(i) and (ii) of this AD. (i) With the accelerometer already installed, check the measurement of the vibration level in-flight, at 12 Hz by following figure 1 to paragraph (g)(2)(i) of this AD. The owner/operator (pilot) holding at least a private pilot certificate may perform this check and must enter compliance with these paragraphs into 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 135.439. Figure 1 to Paragraph (g)(2)(i)-Method of Measurement ER13MR26.003 (ii) Interpret the results in accordance with the instructions in Section 4.4 of ASB AS332-04-00-0001 except you are not required to send any information to Airbus Helicopters. If the vibration level between 11.7 Hz and 12.7 Hz is more than 0.08g (0.40 IPS), before further flight, revise the helicopter configuration by removing the dual hoist system or removing the blade de-icing harnesses in accordance with instructions of section 4.5 through 4.5.2.1 of ASB AS332-04-00-0001. (h) Optional Method of Compliance For helicopters without Airbus Helicopters modification 0722907 installed: Revising the rotorcraft flight manual for your helicopter by inserting the information specified in Appendix 4A, 4B, or 4C of EASB AS332 01.00.96, as applicable to your helicopter model and configuration, and installing a locally made placard on the instrument panel, in accordance with the instructions of section 3.B.1 of EASB AS332 01.00.96, is an acceptable method for compliance with the requirements of paragraph (g)(1) of this AD. (i) 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 responsible Flight Standards 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 (j) 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 responsible Flight Standards Office. (j) Additional Information For more information about this AD, contact Matthew Williams, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4134; email: matthew.t.williams@faa.gov. (k) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) 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. (3) The following material was approved for IBR on April 17, 2026. (i) Airbus Helicopters Alert Service Bulletin ASB AS332-04-00-0001, Issue 002, dated December 4, 2024. (ii) [Reserved] (4) The following material was approved for IBR on May 20, 2020, (85 FR 30589, May 20, 2020). (i) Airbus Helicopters Emergency Alert Service Bulletin AS332 01.00.91, Revision 1, dated December 4, 2019. (ii) Airbus Helicopters Emergency Alert Service Bulletin AS332 01.00.96, Revision 0, dated December 4, 2019. (5) For Airbus material identified in this AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-0000 or (800) 232-0323; fax: (972) 641-3775; or at airbus.com/en/products-services/helicopters/hcare-services/airbusworld. (6) 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. (7) 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 4, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.