SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2022-20-11, Amendment 39-22195 (87 FR 64152, October 24, 2022), (AD 2022-20-11). AD 2022-20-11 applied to certain Bell Textron Canada Limited Model 429 helicopters. AD 2022-20-11 required certain serial-numbered helicopters, an initial and repetitive visual inspection of the rivets at the TR gearbox support assembly for signs of any missing or separated rivet tails, any rivet tails resting at the bottom of the tail boom, and any rivet tails not resting against the tail boom skin. AD 2022-20-11 also required measuring any gaps between the TR gearbox support assembly and the tail boom skin. The FAA issued AD 2022-20-11 to detect failed rivets and rivets with inadequate grip length. The unsafe condition, if not addressed, could result in deterioration of the joint structural integrity, detachment of the TR gearbox support assembly, and loss of helicopter control.

The NPRM was published in the Federal Register on July 23, 2026 (91 FR 46322). The NPRM was prompted by Transport Canada AD CF-2025-60R1, dated January 28, 2026, (Transport Canada AD CF-2025-60R1) (also referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada. The MCAI states that, following reports of numerous failed rivets that were found within the repetitive inspection interval, the manufacturer determined the frequency of repetitive inspections needs to be increased until a terminating action is introduced.

In the NPRM, the FAA proposed to require the same actions as AD 2022-20-11 and reduce the inspection interval.

The FAA is issuing this AD to address the unsafe condition on these products. ( printed page 72771)

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-7227.

Discussion of Final Airworthiness Directive

Comments

The FAA received one comment from an anonymous commenter. The following presents the comment received on the NPRM and the FAA's response to the comment.

Request To Revise the Regulatory Text of the Proposed AD To Include Reporting Results

The anonymous commenter requested that the FAA revise the regulatory text of the proposed AD by removing paragraph (i) of the proposed AD. The commenter stated to maintain robust safety monitoring and ensure foreign type design authorities receive complete fleet usage data, the FAA should remove the no reporting requirement and require operators to submit all required inspection data directly to the manufacturer as specified in the referenced material. The commenter further stated that the proposed AD is designated as an “interim action,” and as such, establishing a centralized data feedback loop directly through the manufacturer is essential for determining whether future design changes or permanent terminating actions are necessary. Additionally, the commenter stated, without structured, mandatory reporting, neither the manufacturer nor foreign civil aviation authorities will have complete visibility into the failure rates occurring across the U.S. fleet. Finally, the commenter stated by suppressing this reporting mechanism it limits the manufacturer's ability to perform comprehensive fleet-wide root-cause analyses, which could hinder the development of long-term terminating modifications.

The FAA disagrees. The FAA is following the actions of the state of design, which did not mandate reporting in Transport Canada AD CF-2025-60R1. Paragraph (i) of this AD is highlighting the fact for operators that they may submit reports, if requested, when accomplishing the service bulletin, but reporting is not being mandated for AD compliance or to address the unsafe condition. The FAA did not change this AD as a result of this comment.

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 Transport Canada AD CF-2025-60R1, which specifies procedures for initial and repetitive general visual inspections and detailed inspections of the affected rivets at the joint between the tail boom skin and the TR gearbox support assembly.

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, the MCAI, and the Referenced Material

Where the material referenced in Transport Canada AD CF-2025-60R1, specifies to obtain an approved Bell structural repair scheme to repair any gaps, this AD requires repairing those gaps in accordance with a method approved by the Manager, International Validation Branch, FAA; or Transport Canada; or Bell Textron Canada Limited's Transport Canada Design Approval Organization (DAO).

Interim Action

The FAA considers that this AD is 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 147 helicopters of U.S. registry.

The FAA estimates the following costs to comply with this AD:

The FAA estimates the following costs to do any repairs that will be required based on the results of the inspection. The agency has no way of determining the number of helicopters that might need this repair:

The FAA has no way to determine the cost estimate of repairing a gap using a method approved by the Manager, International Validation Branch, FAA; Transport Canada; or Bell Textron Canada Limited's Transport Canada DAO.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, ( printed page 72772) 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: