AD 2023-24-06

This AD is effective January 31, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 31, 2024.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2023-1889; 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 final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Material Incorporated by Reference:

• For service information identified in this final rule, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu.

• You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at regulations.gov under Docket No. FAA-2023-1889.

Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7241; email: sungmo.d.cho@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2021-25-04, Amendment 39-21847 (86 FR 71129, December 15, 2021) (AD 2021-25-04). AD 2021-25-04 applied to RRD Model Trent 1000-AE3, Trent 1000-CE3, Trent 1000-D3, Trent 1000-G3, Trent 1000-H3, Trent 1000-J3, Trent 1000-K3, Trent 1000-L3, Trent 1000-M3, Trent 1000-N3, Trent 1000-P3, Trent 1000-Q3, and Trent 1000-R3 engines. AD 2021-25-04, which was prompted by EASA AD 2020-0243, dated November 5, 2020 (EASA AD 2020-0243), required revising the ALS of the operator's 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. The FAA issued AD 2021-25-04 to prevent the failure of critical rotating parts, which could result in failure of one or more engines, loss of thrust control, and loss of the airplane.

Since the FAA issued AD 2021-25-04, EASA superseded EASA AD 2020-0243 with EASA AD 2022-0247, dated December 14, 2022 (EASA AD 2022-0247) and then superseded EASA AD 2022-0247 with EASA AD 2023-0115, dated June 7, 2023 (EASA AD 2023-0115).

The NPRM published in the Federal Register on September 18, 2023 (88 FR 63885); corrected on September 27, 2023 (88 FR 66316). The NPRM was prompted by EASA AD 2023-0115 (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 the manufacturer published a revised engine TLM to introduce new or more restrictive tasks and limitations and associated thresholds and intervals for life-limited parts.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2023-1889.

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 tasks and limitations and associated thresholds and intervals for life-limited parts.

The FAA received a comment from The Boeing Company (Boeing). Boeing supported the NPRM without change.

These products have been approved by the 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, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered the comment received, and determined that air safety requires adopting the 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.

The FAA reviewed EASA AD 2023-0115, which specifies procedures for operators to revise 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 service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in ADDRESSES.

Where paragraph (3) of EASA AD 2023-0115 specifies revising the approved Aircraft Maintenance Programme within 12 months after the effective date of EASA AD 2023-0115, this AD requires revising the ALS of the existing approved engine maintenance or inspection program, as applicable, within 90 days after the effective date of this AD.

This AD does not require compliance with paragraphs (1), (2), (4), and (5) of EASA AD 2023-0115.

The FAA estimates that this AD affects 2 engines installed on airplanes of U.S. registry.

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

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.

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.

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

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive 2021-25-04, Amendment 39-21847 (86 FR 71129, December 15, 2021); and

b. Adding the following new airworthiness directive: