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 RRD Model BR700-725A1-12 engines. The NPRM was published in the Federal Register on July 15, 2026 (91 FR 43343). The NPRM was prompted by EASA AD 2024-0136, dated July 11, 2024, issued by EASA, which is the Technical Agent for the Member States of the European Union (EASA AD 2024-0136) (also referred to as the MCAI). The MCAI states that the manufacturer revised the ALS of the existing TLM to introduce new or more restrictive airworthiness limitations and associated thresholds and intervals for life-limited parts.

In the NPRM, the FAA proposed to require revising the ALS of the operator's existing approved engine maintenance or inspection program, as applicable, to incorporate new or more restrictive instructions and associated thresholds and intervals for life-limited parts. 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-2026-7219.

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 Include Non-Destructive Testing Inspections

An individual commenter stated that the FAA focuses primarily on removing parts once they reach the new cycle limit but fails to mandate intermediate non-destructive testing inspections for components approaching the new threshold. The commenter noted that without requiring inspections prior to part removal, the FAA leaves an undetected safety risk for engines that may already have micro-cracks propagating toward failure before reaching the new lower limit. The FAA infers that the commenter is requesting that non-destructive testing inspections be required for parts approaching their life-limit threshold.

The FAA disagrees with this request because the airworthiness limitations section includes inspections at piece part opportunity and life limits which are designed to appropriately mitigate the risk associated with 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 EASA AD 2024-0136, which specifies procedures for revising the ALS of the existing approved engine maintenance or inspection program, as applicable, to incorporate new or more restrictive tasks and limitations and associated thresholds and intervals for life-limited parts. 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

Where paragraph (3) of EASA AD 2024-0136 specifies revising the approved Aircraft Maintenance Programme within 12 months after the effective date of EASA AD 2024-0136, this AD requires revising the ALS of the existing approved engine maintenance or inspection program, as applicable, within 30 days after the effective date of this AD. ( printed page 70778)

Costs of Compliance

The FAA estimates that this AD affects 758 engines installed on airplanes of U.S. registry.

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

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: