SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus Helicopters Deutschland GmbH Model MBB-BK 117 D-3 helicopters. The NPRM was published in the Federal Register on September 15, 2025 (90 FR 44347). The NPRM was prompted by EASA AD 2025-0029, dated February 7, 2025 (EASA AD 2025-0029) (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 an occurrence of excessive vibrations in flight was reported. The MCAI further states that subsequent investigations revealed that an incorrect installation of the angular ball bearing of the control ring assembly caused wear of the axial bearing seat. This condition, if not addressed, could result in axial play between the swashplate bearing ring assembly and the control ring assembly and consequent reduced control of the helicopter.

In the NPRM, the FAA proposed to require a one-time inspection of the affected swashplates and, depending on the results of the inspection, corrective actions. The NPRM also proposed to prohibit the installation of an affected swashplate on a helicopter unless certain requirements are met, as specified in EASA AD 2025-0029.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-2540.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from two commenters. The commenters were an individual who supported the NPRM without change, and the Citizens Rulemaking Alliance. The following presents the comments received on the NPRM from the Citizens Rulemaking Alliance 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. 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, 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 remove any reporting provisions 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.

The FAA clarifies that this AD only incorporates by reference EASA AD 2025-0029, not the manufacturer service information referenced in that EASA AD. The FAA posted EASA AD 2025-0029 to the AD docket when the NPRM was published in the Federal Register . The material referenced in EASA AD 2025-0029 may only be posted before the final rule's publication if it is already publicly available or if there is written consent from the owner of that material. Additionally, the FAA provided notice in the NPRM that the material referenced in EASA AD 2025-0029 will be available in the AD docket after this AD is published.

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. ( printed page 33597)

Request To Consider Impact on Small Entities

The Citizens Rulemaking Alliance requested that the FAA prepare an initial regulatory flexibility analysis that takes into account parts, labor, aircraft downtime, and specific small entity impacts. Additionally, the commenter requested that the FAA adopt less burdensome alternatives for small operators, such as explicit AMOC alternatives, temporary ferry flight allowances, and flexible compliance intervals.

The FAA has considered the AD's impact on small entities and provides the following factual basis for its Regulatory Flexibility Act (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 (Pub. L. 104-121, 110 Stat. 857, Mar. 29, 1996) and the Small Business Jobs Act of 2010 (Pub. L. 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 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. Note that the SBA definition of a small business applies to the parent company and all affiliates as a single entity.

This AD impacts 21 entities, including 6 small entities. The table below displays the industries with affected entities, along with the number of affected entities and the number of small entities impacted in each industry.

The following table displays the high-case cost impact of the AD on all six small entities.

RFA Conclusions

While the FAA has determined that this AD affects a substantial number of small entities, the high-case compliance cost of the AD requirements relative to each small entity's annual revenue is minimal. In the high-case scenario, the AD's cost as a percentage of annual revenue imposes a cost no greater than 1.88 percent. Therefore, as provided in section 605(b), the FAA certifies that this AD will not result in a significant economic impact on a substantial number of small entities. The FAA did not change this AD as a result of this comment. ( printed page 33598)

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 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 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 2025-0029, which specifies procedures for a one-time inspection of swashplates having part number D623M2050102 and a serial number up to 0487 inclusive and, depending on the inspection results, accomplishing corrective actions and contacting Airbus Helicopters for approved repair instructions. Corrective actions include inspecting the control ring assembly and, depending on the results, repair or replacement of the control ring assembly or repair of the surface protection of the control ring assembly.

The MCAI also allows the accomplishment of corrective actions using the instructions of the applicable Aircraft Maintenance Manual (AMM) 62-32-00, 6-7. Corrective actions specified in the applicable AMM include the examination of bolts, single row ball bearings, bushings, and washers and, depending on the results, repair or replacement of these parts, as applicable.

Additionally, the MCAI allows the installation of an affected swashplate on a helicopter if it is inspected before it is installed, and if any corrective actions are completed in accordance with the instructions of the service material.

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.

Differences Between This AD and the MCAI

The MCAI applies to Model MBB-BK117 D-3m helicopters, whereas this AD does not because that model does not have an FAA type certificate. The MCAI requires reporting inspection results to the manufacturer, whereas this AD does not. The MCAI does not apply to helicopters where it cannot be determined that a swashplate has been inspected, whereas this AD applies to those helicopters.

Costs of Compliance

The FAA estimates that this AD affects 55 helicopters of the U.S. registry. The FAA estimates that following costs to comply with this AD.

The FAA estimates the following costs to do any necessary on-condition actions that would be required based on the results of any required actions. The FAA has no way of determining the number of helicopters that might need these on-condition actions. However, the FAA estimates the low- and high-case costs for each helicopter. If a helicopter only incurs required costs (low-case scenario), each helicopter will incur $340 in compliance costs. If a helicopter incurs all required and on-condition costs (high-case scenario), each helicopter could incur up to $9,420 in compliance costs.

( printed page 33599)

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,

(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:

91 FR 33595