SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2021-23-04, Amendment 39-21802 (86 FR 68892, December 6, 2021) (AD 2021-23-04), which applied to Leonardo S.p.A. Model A109E helicopters. AD 2021-23-04 required repetitive inspections of the intersection of the lateral pylon and floor spar at STA 1815 for cracking and, depending on the findings, repair. 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. Since the FAA issued AD 2021-23-04, it was determined that additional helicopter models are affected by the unsafe condition.

The NPRM was published in the Federal Register on September 30, 2025 (90 FR 46768). The NPRM was prompted by EASA AD 2024-0004, dated January 5, 2024 (EASA AD 2024-0004) (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 Leonardo developed a modification to prevent cracking in the intersection of the lateral pylon and floor spar at STA 1815 on the left- and right-hand sides.

In the NPRM, the FAA proposed to continue to require repetitive inspections of the affected area for cracking and add additional helicopter models to the applicability. The NPRM also proposed to require modification of the affected area, which would be terminating action for the repetitive inspections. The FAA is issuing this AD to address the unsafe condition on these products.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-2556.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from the Citizens Rulemaking Alliance. The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Issue an NPRM or Justify Forgoing Notice and Comment

The Citizens Rulemaking Alliance requested that the FAA either convert this action to an NPRM or provide its justification for finding good cause to bypass notice and comment procedures, reopen the comment period for at least 60 days, and commit to promptly superseding the AD with an NPRM while suspending enforcement of non-time-critical provisions pending comment. The commenter asserted the FAA has not adequately justified use of the good cause exemption to bypass notice and comment and the 30-day delayed effective date.

The FAA notes the comment was submitted in response to an NPRM for which the FAA provided a 45-day comment period. This final rule is effective 35 days after its publication in the Federal Register . Therefore, no change to this AD is necessary.

Request To Consider Impact on Small Entities

The Citizens Rulemaking Alliance requested that the FAA either provide the factual basis for its Regulatory Flexibility Act (RFA) certification that the AD will not have a significant economic impact on a substantial number of small entities or prepare an initial regulatory flexibility analysis and consider less burdensome alternatives for small operators. The commenter stated that the FAA should also reopen the comment period for at least 60 days to allow comment on that analysis.

The FAA has considered the AD's impact on small businesses and provides the following factual basis for its RFA certification.

The Regulatory Flexibility Act of 1980, Public Law 96-354, 94 Stat. 1164 (5 U.S.C. 601-612), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (Public Law 104-121, 110 Stat. 857, Mar. 29, 1996) and the Small Business Jobs Act of 2010 (Public Law 111-240, 124 Stat. 2504, Sept. 27, 2010), requires Federal agencies to consider the effects of the regulatory action on small business and other small entities and to minimize any significant economic impact. The term “small entities” comprises small businesses and not-for-profit organizations that are independently owned and operated and are not dominant in their fields, and governmental jurisdictions with populations of less than 50,000.

Small Entities to Which This AD Applies

The FAA used the definition of small entities in the RFA for this analysis. The RFA defines small entities as small businesses, small governmental jurisdictions, or small organizations. In 5 U.S.C. 601(3), the RFA defines “small business” to have the same meaning as “small business concern” under section 3 of the Small Business Act. The Small Business Act authorizes the Small Business Administration (SBA) to ( printed page 26903) define “small business” by issuing regulations.

The SBA (2023) has established size standards for various types of economic activities, or industries, under the North American Industry Classification System (NAICS). These size standards generally define small businesses based on the number of employees or annual receipts. The following table provides the SBA size standards for all industries with at least 1 entity impacted by this AD. Note that the SBA definition of a small business applies to the parent company and all affiliates as a single entity.

To identify small entities, the FAA first identified the primary NAICS of the entity or parent company, and then used data from different sources ( e.g., company annual reports, Bureau of Transportation Statistics) to determine whether the entity meets the applicable size standard. The FAA provides the estimated number of small entities affected by this AD:

Projected Reporting, Recordkeeping, and Other Compliance Requirements

The FAA estimates operators will incur either an inspection cost of $1,394 annually or a one-time modification cost of $25,860 per helicopter. Once an operator incurs the one-time modification cost, the operator will no longer incur annual inspection costs. The FAA cannot estimate when each operator will incur this modification cost. In addition, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. The FAA analyzes the cost of each compliance method relative to the annual revenue of each small entity. The following table shows the estimated compliance costs by each NAICS industry. ( printed page 26904)

Significant Alternatives Considered

The FAA evaluated the alternative of not promulgating this AD but ultimately deemed that this alternative would create a significant safety hazard. Since the issuance of AD 2021-23-04, which affected certain Leonardo S.p.A. Model A109E helicopters, it has been determined that the risk of structural cracking at the intersection of the lateral pylon and floor spar extends to additional helicopter models. Relying on the existing requirements would leave these additional models unmonitored. By expanding the applicability and requiring the modification, this AD addresses the unsafe condition and prevents potential structural failure, ensuring a level of safety that the alternative of no action could not provide.

RFA Conclusions

Based on average compliance costs, the FAA has determined that the financial impacts of this AD are not disproportionate to small entities. Therefore, the FAA did not change this AD as a result of this comment.

Request To Comply With the Paperwork Reduction Act (PRA)

The Citizens Rulemaking Alliance requested that the FAA revise the AD to comply with the PRA if reporting is required or make any reporting provisions voluntary until PRA requirements are satisfied.

The FAA notes that paragraph (i) of this AD specifies that this AD does not require reporting. If an AD were to require reporting, the preamble of the AD would include a paragraph titled “Paperwork Reduction Act” that would provide the applicable OMB control number, required PRA statements, and the estimated time to collect the required information (burden). Any costs associated with the reporting requirement would be included in the Costs of Compliance section in the preamble of the AD. Therefore, the FAA did not change this AD as a result of this comment.

Request To Make Incorporation by Reference (IBR) Materials Reasonably Available

The Citizens Rulemaking Alliance stated that the FAA's current practices for IBR frequently fail to meet the legal and regulatory standards for reasonable availability. The commenter called on the FAA to guarantee that all IBR materials are easily and freely accessible to the public and affected parties for the duration of the comment period and to reopen the comment period for at least 60 days to accommodate this access.

The FAA's practices comply with 5 U.S.C. 552(a) of the Administrative Procedure Act and 1 CFR part 51. The FAA makes IBR materials available in the AD docket when the final rule is published in the Federal Register , following formal approval of the IBR by the Office of the Federal Register. Materials may only be posted before the final rule's publication if they are already publicly available or if there is written consent from the owner of the IBR material. All relevant materials incorporated by reference will be accessible in the AD docket on Regulations.gov, which the public can access without registration or fees.

The FAA also provides summaries and access details in the preamble and regulatory text, makes materials available for inspection at FAA and National Archives and Records Administration (NARA) offices, offers publisher contact information, and obtains formal IBR approval from the Office of the Federal Register. These efforts are intended to ensure that all IBR materials meet the “reasonably available” standard required by 1 CFR part 51. Therefore, the FAA did not change this AD as a result of this comment.

Request To Provide the Regulatory Evaluation

The Citizens Rulemaking Alliance requested that the FAA add to the AD docket the regulatory evaluation of the proposed AD and reopen the comment period for at least 60 days to allow for public input on the additional cost information.

The FAA's practice is to add the regulatory evaluation of the proposed AD in the NPRM, not as a separate document in the AD docket.

In the Costs of Compliance section of the NPRM, the FAA disclosed the estimated number of work hours, the number of helicopters affected on the U.S. registry (which has been updated in this final rule), estimated parts cost, and the aggregate costs for the U.S. fleet. The FAA has revised the Costs of Compliance section to clarify costs of this AD. Since the FAA provided the regulatory evaluation in the NPRM, and the commenter did not provide additional information for the FAA to consider in its analysis, it is not necessary to reopen the comment period or provide additional information in the AD docket.

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 ( printed page 26905) 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 EASA AD 2024-0004, which 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 provides 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.

Costs of Compliance

The FAA estimates that this AD affects 81 helicopters of U.S. Registry. The FAA estimates that operators will incur an annual inspection cost of $1,394 ($510 per inspection cycle) until they make the modification, and then they will incur a one-time modification cost of $25,860 per helicopter ($12,930 per fuselage side). Once an operator incurs a one-time modification cost, the operator will no longer incur inspection costs. The FAA does not estimate when operators would need to modify their helicopter.

The FAA recognizes that operators might incur additional costs, such as helicopter downtime. However, the FAA cannot quantify these costs. According to the manufacturer, some of the costs of this 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 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.

The Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: