AD 2023-26-04

This AD is effective February 7, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of February 7, 2024.

AD Docket: You may examine the AD docket at regulations.gov under Docket No.FAA-2023-1892; 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-2023-1892.

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 by adding an AD that would apply to all 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. The NPRM published in the Federal Register on September 29, 2023 (88 FR 67121). The NPRM was prompted by EASA AD 2023-0087, dated April 26, 2023 (EASA AD 2023- 0087) (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 RRD engine time limits manual (TLM) provides instructions for visual inspection of the IP8 and HP3 air transfer tubes and front bearing housing IP8 air feed tubes for cracking, damage, or air leakage wear at intervals consistent with critical part life assessments. Also, certain inspection intervals mandated by the MCAI, and not previously included in the TLM, are shorter than the engine shop visit intervals. Thus, more frequent visual inspections of the IP8 and HP3 air transfer tubes and front bearing housing IP8 air feed tubes are necessary. The manufacturer issued service information that provides instructions for visual inspections of the IP8 and HP3 air transfer tubes and front bearing housing IP8 air feed tubes.

In the NPRM, the FAA proposed to require initial and repetitive visual inspections of the IP8 and HP3 air transfer tubes and front bearing housing IP8 air feed tubes for cracking, damage, or air leakage wear, and replacement, if necessary. 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-2023-1892.

The FAA received one 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 2023-0087, which specifies procedures for performing initial and repetitive visual inspections of the IP8 and HP3 air transfer tubes and front bearing housing IP8 air feed tubes for cracking, damage, or air leakage wear, and replacement if necessary.

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 ADDRESSES.

The FAA estimates that this AD affects 16 engines installed on airplanes of U.S. registry.

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

The FAA estimates the following costs to do any necessary replacements that would be required based on the results of the inspection. The agency has no way of determining the number of aircraft that might need these replacements:

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.

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 adding the following new airworthiness directive: