Comments Invited The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under the ADDRESSES section. Include "Docket No. FAA-2025-2271; Project Identifier MCAI-2025-01166-R" at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this final rule because of those comments. Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule. Confidential Business Information CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this AD contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this AD, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as "PROPIN." The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this AD. Submissions containing CBI should be sent to Carl Franklin, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5291. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2025-0131, dated June 16, 2025 (EASA AD 2025-0131) (also referred to as the MCAI), to correct an unsafe condition on Leonardo S.p.A. Model A109E, A109LUH, A109S, AW109SP, A119, and AW119MKII helicopters. The MCAI states that the manufacturer's maintenance instructions for the swashplate assembly installation included improper torque values for affected swashplate nuts having part number NAS1805-4 that attach the swashplate support to the main transmission. The FAA is issuing this AD to detect and correct the condition of the swashplate nuts, which if not addressed, could result in failure of the main rotor function and consequent loss of control of the helicopter. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-2271. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed EASA AD 2025-0131, which specifies procedures for repetitive visual inspections of the affected swashplate nuts for cracks, fretting, or slippage marks and, depending on the results, replacement of the affected nuts and reinstallation of the swashplate assembly. EASA AD 2025-0131 also prohibits reinstallation of the swashplate assembly on any helicopter using certain manufacturer maintenance instructions. EASA AD 2025-0131 also specifies that replacement of the affected swashplate nuts and reinstallation of the swashplate assembly constitutes terminating action for the repetitive inspections. 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. FAA's Determination 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 is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. AD Requirements This AD requires accomplishing the actions specified in EASA AD 2025-0131, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this AD. See "Differences Between this AD and the MCAI" for a discussion of the general differences included in this AD. Differences Between This AD and the Referenced Material The MCAI applies to Leonardo Model A109LUH helicopters, whereas this AD does not because that model does not have an FAA type certificate. The MCAI specifies reinstallation of the swashplate assembly within 200 flight hours after a replacement required by any inspection or within 2,400 flight hours after the effective date if replacement is not required. The MCAI states that reinstallation of the swashplate assembly is a terminating action for the inspection requirements of the MCAI. For this AD, the word "reinstallation" means "reconfiguration" as reinstallation of the swashplate is required before return to service. This AD also does not require the 2,400 flight hour swashplate assembly "reconfiguration" as this is considered a long-term action that would allow for prior opportunity for public comment. If replacement is not required, this AD will allow the swashplate assembly reconfiguration and corrective actions as optional terminating action for the inspection requirements of the AD. The FAA may consider future rulemaking with prior public comment on this action. Explanation of Required Compliance Information In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, EASA AD 2025-0131 is incorporated by reference in this AD. This AD requires compliance with EASA AD 2025-0131 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this AD. Using common terms that are the same as the heading of a particular section in EASA AD 2025-0131 does not mean that operators need comply only with that section. For example, where the AD requirement refers to "all required actions and compliance times," compliance with this AD requirement is not limited to the section titled "Required Action(s) and Compliance Time(s)" in EASA AD 2025-0131. Material required by EASA AD 2025-0131 for compliance will be available at regulations.gov under Docket No. FAA-2025-2271 after this AD is published. Justification for Immediate Adoption and Determination of the Effective Date Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq. ) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for "good cause," finds that those procedures are "impracticable, unnecessary, or contrary to the public interest." Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause. An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because improper torque value application on affected swashplate nuts that attach the swashplate support to the main transmission could lead to failure of the main rotor function, which could result in loss of control of the helicopter. The FAA has no information pertaining to the extent of fatigue damage on swashplate nuts that may currently exist in helicopters or how quickly the condition may propagate to failure, therefore, the initial instance of the inspections must be accomplished within 50 hours time-in-service (TIS) after the effective date of this AD. These helicopters average approximately 50 hours TIS a month with some over 100 hours TIS a month. Based on this, the initial inspection compliance time is shorter than the time necessary for the public to comment and for publication of the final rule. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b). In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment. Regulatory Flexibility Act The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this rule without prior notice and comment, RFA analysis is not required. Costs of Compliance The FAA estimates that this AD affects 173 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 Inspect affected swashplate nuts 4 work-hours × $85 per hour = $340 $0 $340 $58,820 The FAA estimates the following costs to do any necessary replacements that would be required based on the results of the inspection. The FAA has no way of determining the number of helicopters that might need these replacements: On-Condition Costs Action Labor cost Parts cost Cost per product Replace affected swashplate nuts and reconfigure swashplate assembly 40 work-hours × $85 per hour = $3,400 $21 $3,421 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 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, and (2) Will not affect intrastate aviation in Alaska. 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 adding the following new airworthiness directive: 2025-18-01 Leonardo S.p.A. Helicopters: Amendment 39-23128; Docket No. FAA-2025-2271; Project Identifier MCAI-2025-01166-R. (a) Effective Date This airworthiness directive (AD) is effective September 25, 2025. (b) Affected ADs None. (c) Applicability This AD applies to Leonardo S.p.A. Model A109E, A109S, AW109SP, A119, and AW119 MKII helicopters, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code: 6220, Main Rotor Head. (e) Unsafe Condition This AD was prompted by a report that certain manufacturer maintenance instructions for swashplate assembly installation specified incorrect torque values for certain swashplate nuts. The FAA is issuing this AD to detect and correct the condition of the swashplate nuts. The unsafe condition, if not addressed, could result in failure of the main rotor function and consequent 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 (EASA) AD 2025-0131, dated June 16, 2025 (EASA AD 2025-0131). (h) Exceptions to EASA AD 2025-0131 (1) Where EASA AD 2025-0131 refers to its effective date, this AD requires using the effective date of this AD. (2) Where EASA AD 2025-0131 refers to flight hours (FH), this AD requires using hours time-in-service (TIS). (3) Where EASA AD 2025-0131 defines Group 1 helicopters as "A109E, A109LUH, A109S, AW109SP, A119 and AW119MKII helicopters, all s/n, as defined in Part I of the applicable ASB", this AD requires replacing this text with "A109E, A109LUH, A109S, AW109SP, A119 and AW119MKII helicopters, all s/n, as defined in Planning Information, paragraph A., Effectivity, Part I, of the applicable SB". (4) Where EASA AD 2025-0131 states "replace the damaged affected nuts with new nuts", this AD requires replacing that text with "replace the damaged affected nuts with unused nuts having part number NAS1805-4". (5) Where EASA AD 2025-0131 states "reinstall the swashplate assembly", this AD requires replacing that text with "reconfigure the swashplate assembly". (6) Where paragraph (3) of EASA AD 2025-0131 requires reinstallation of the swashplate assembly and inspections and corrective actions for certain helicopters within 2,400 FH after the effective date of EASA AD 2025-0131, this AD allows it as optional terminating action for the inspection requirement of this AD. (7) This AD does not adopt the "Remarks" section of EASA AD 2025-0131. (i) No Reporting Requirement Although the service material referenced in EASA AD 2025-0131 specifies to submit certain information to the manufacturer, this AD does not require that action. (j) Special Flight Permits Special flight permits are prohibited. (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 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 local Flight Standards District Office/certificate holding district office. (l) Additional Information For more information about this AD, contact Carl Franklin, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5291; email: carl.j.franklin@faa.gov. (m) 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. (i) European Union Aviation Safety Agency (EASA) AD 2025-0131, dated June 16, 2025. (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 this EASA AD 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 September 4, 2025. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.