# [Amended]
**AGENCY:**
Federal Aviation Administration (FAA), DOT.
**ACTION:**
Notice of proposed rulemaking (NPRM).
**SUMMARY:**
The FAA proposes to supersede Airworthiness Directive (AD) 2021-23-04 which applies to certain Leonardo S.p.A. Model A109E helicopters. AD 2021-23-04 requires repetitive inspections of the intersection of the lateral pylon and floor spar at station (STA) 1815 for cracking and repair, depending on the findings. Since the FAA issued AD 2021-23-04, it was determined that additional helicopter models are affected by the unsafe condition. Additionally, the manufacturer has developed a modification that provides terminating action for the repetitive inspections. This proposed AD would continue to require repetitive inspections of the affected area for cracking and would add additional helicopter models to the applicability. This proposed AD would also require modifying the affected area, which would be terminating action for the repetitive inspections. The FAA is proposing this AD to address the unsafe condition on these products.
**DATES:**
The FAA must receive comments on this proposed AD by November 14, 2025.
**ADDRESSES:**
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
• *Federal eRulemaking Portal:* Go to *regulations.gov* . Follow the instructions for submitting comments.
• *Fax:* (202) 493-2251.
• *Mail:* U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
• *Hand Delivery:* Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
*AD Docket:* You may examine the AD docket at *regulations.gov* under Docket No. FAA-2025-2556; 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 NPRM, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.
*Material Incorporated by Reference:*
• For European Union Aviation Safety Agency (EASA) material identified in this NPRM, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: *[email protected];* website: *easa.europa.eu.* You may find the EASA material on the EASA website at *ad.easa.europa.eu.*
• You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. The EASA material is also available at *regulations.gov* under Docket No. FAA-2025-2556.
**FOR FURTHER INFORMATION CONTACT:**
Dan McCully, Program Manager, International Validation Branch, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; phone: (404) 474-5548; email: *[email protected].*
**SUPPLEMENTARY INFORMATION:**
**Comments Invited**
The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the *ADDRESSES* section. Include “Docket No. FAA-2025-2556; Project Identifier MCAI-2024-00034-R” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, 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 proposal 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 NPRM.
**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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Dan McCully, Program Manager, International Validation Branch, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.
**Background**
The FAA issued AD 2021-23-04, Amendment 39-21802 (86 FR 68892, December 6, 2021) (AD 2021-23-04), for Leonardo S.p.a. Model A109E helicopters. AD 2021-23-04 requires repetitive inspections of the intersection of the lateral pylon and floor spar at STA 1815 for cracking and, depending on the findings, repair, as specified in EASA AD 2020-0256, dated November 17, 2020 (EASA AD 2020-0256). The FAA issued AD 2021-23-04 to address cracking in the intersection of the lateral pylon and floor spar at STA 1815 on the left- and right-hand sides, which, if not addressed, could affect the structural integrity of the helicopter.
**Actions Since AD 2021-23-04 Was Issued**
After the FAA issued AD 2021-23-04, EASA, which is the Technical Agent for the Member States of the European Union, issued superseding EASA AD 2022-0153, dated July 28, 2022 (EASA AD 2022-0153), to correct an unsafe condition for Leonardo S.p.A. Helicopters Model A109E helicopters, all serial numbers (S/N); Model A109S helicopters, all S/Ns up to 22199 inclusive; and Model A109LUH helicopters, all S/Ns. EASA AD 2022-0153 was issued after it was determined that additional helicopters may be affected by the unsafe condition described in EASA AD 2020-0256; therefore, EASA AD 2022-0153 retained the requirements of EASA AD 2020-0253, which was superseded, and increased the applicability by expanding applicable Model A109E helicopters to all S/Ns and adding all Model A109LUH and certain serial-numbered Model A109S helicopters.
After EASA AD 2022-0153 was issued, Leonardo developed a modification which provides terminating action for the repetitive inspections; EASA subsequently issued EASA AD 2024-0004, dated January 5, 2024 (EASA AD 2024-0004) (also referred to as the MCAI), which supersedes EASA AD 2022-0153, retains the inspection requirements of EASA AD 2022-0153, and requires a modification, which consists of a fuselage reinforcement, of the affected area as terminating action for the repetitive inspections. This proposed AD was prompted by reports of cracking in the center fuselage frame assembly in the intersection of the lateral pylon and floor spar at STA 1815 on the left- and right-hand sides and the subsequent development of a modification to that area to prevent cracking. The unsafe condition, if not addressed, could affect the structural integrity of the helicopter.
You may examine EASA AD 2024-0004 in the AD docket at *regulations.gov* under Docket No. FAA-2025-2556.
**Material Incorporated by Reference Under 1 CFR Part 51**
EASA AD 2024-0004 specifies procedures for repetitive inspections of STA 1815 for cracking, fluorescent liquid penetrant inspections of any cracking to determine the extent of the cracking, or other damage, such as deformation or corrosion, and modifying the affected area by reinforcing the fuselage, which would provide 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 (CAA) 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. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
**Proposed AD Requirements in This NPRM**
This proposed AD would require accomplishing the actions specified in EASA AD 2024-0004, described previously as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this proposed AD. See “Differences Between this Proposed AD and the MCAI” for a discussion of the general differences included in this proposed AD.
**Differences Between This Proposed AD and the MCAI**
The MCAI applies to Model A109LUH helicopters, whereas this proposed AD would not because that model is not FAA-type certificated. Where the MCAI provides credit for only initial inspections, this proposed AD would provide credit for any inspections.
**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 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, the FAA proposes to incorporate EASA AD 2024-0004 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2024-0004 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2024-0004 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 2024-0004. Service material required in EASA AD 2024-0004 for compliance will be available at *regulations.gov* under Docket No. FAA-2025-2556 after the FAA final rule is published.
**Costs of Compliance**
The FAA estimates that this AD, if adopted as proposed, would affect 119 helicopters of U.S. Registry. The FAA estimates the following costs to comply with this proposed AD.
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. |
| --- | --- | --- | --- | --- |
| Inspection | Up to 6 work-hours × $85 per hour = $510 per inspection cycle | $0 | Up to $510 per inspection cycle | Up to $35,700 per inspection cycle. |
| Modification | 120 workhours × $85 per fuselage side | 2,730 | $3,100 per fuselage side | $368,900 per fuselage side. |
The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators.
**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 determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
(1) Is not a “significant regulatory action” under Executive Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment**
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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
2. The FAA amends § 39.13 by:
a. Removing Airworthiness Directive 2021-23-04, Amendment 39-21802 (86 FR 68892, December 6, 2021); and
b. Adding the following new airworthiness directive:
*Leonardo S.p.A.:* Docket No. FAA-2025-2556; Project Identifier MCAI-2024-00034-R.
**(a) Comments Due Date**
The FAA must receive comments on this airworthiness directive (AD) by November 14, 2025.
**(b) Affected ADs**
This AD replaces AD 2021-23-04, Amendment 39-21802 (86 FR 68892, December 6, 2021).
**(c) Applicability**
This AD applies to Leonardo S.p.A. Model A109E and Model A109S helicopters, certificated in any category, as identified in European Union Aviation Safety Agency (EASA) AD 2024-0004, dated January 5, 2024 (EASA AD 2024-0004).
**(d) Subject**
Joint Aircraft Service Component (JASC) Code 5300, Fuselage structure.
**(e) Unsafe Condition**
This AD was prompted by reports of cracking in the center fuselage frame assembly in the intersection of the lateral pylon and floor spar at station 1815 on the left- and right-hand sides and the subsequent development of a modification to that area to prevent cracking. The FAA is issuing this AD to address this cracking which, if not addressed, could affect the structural integrity 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, EASA AD 2024-0004.
**(h) Exceptions to EASA AD 2024-0004**
(1) Where EASA AD 2024-0004 requires compliance in terms of flight hours, this AD requires using hours time-in-service.
(2) Where EASA AD 2024-0004 refers to “[the effective date of EASA 2020-0256]”, this AD requires using the effective date of AD 2021-23-04, which is January 10, 2022.
(3) Where EASA AD 2024-0004 refers to its effective date and August 11, 2022 (the effective date of EASA AD 2022-0153, dated July 28, 2022), this AD requires using the effective date of this AD.
(4) Where paragraphs (3) and (4) of EASA AD 2024-0004 specifies damage, for the purposes of this AD, damage can be indicated by, but not limited to, corrosion or deformation.
(5) Where paragraph (5) of EASA AD 2024-0004 specifies contacting Leonardo for approved repair instructions and accomplishing those instructions accordingly, this AD requires corrective action must be done in accordance with a method approved by the Manager, International Validation Branch, FAA; or EASA; or Leonardo S.p.A. Helicopters' EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.
(6) Where paragraph (7) of EASA AD 2024-0004 applies to initial inspections, for this AD, replace that text with “any inspection”.
(7) Where paragraph (8) of EASA AD 2024-0004 allows credit for repairs accomplished in accordance with the applicable Leonardo approved repair instructions, whereas this AD does not allow that credit.
(8) Where the material referenced in EASA AD 2024-0004 specifies discarding parts, this AD requires removing those parts from service.
(9) This AD does not adopt the “Remarks” section of EASA AD 2024-0004.
**(i) No Reporting Requirement**
Although the service material referenced in EASA AD 2024-0004 specifies submitting certain information to the manufacturer, this AD does not include 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: *[email protected].*
(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 Dan McCully, Program Manager, International Validation Branch, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; phone: (404) 474-5548; email: *[email protected].*
**(m) Material Incorporated by Reference**
(1) The Director of the Federal Register approved the incorporation by reference of the service material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service material as applicable to do the actions required by this AD, unless this AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2024-0004, dated January 5, 2024.
(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: *[email protected];* website: *easa.europa.eu.* You may find the EASA material 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 Pkwy., 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 *[email protected].*
Issued on September 26, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.