FAA-2025-03459

Document Headings Document headings vary by document type but may contain the following: • the agency or agencies that issued and signed a document • the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to • the agency docket number / agency internal file number • the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of Transportation Federal Aviation Administration • 14 CFR Part 39 • [Docket No. FAA-2024-2424; Project Identifier AD-2024-00416-E; Amendment 39-22970; AD 2025-04-12] • RIN 2120-AA64 AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) Model LEAP-1A, LEAP-1B, and LEAP-1C engines. This AD was prompted by a manufacturer investigation that revealed a quality escape for low-pressure turbine (LPT) disks made from forgings with nonconforming grain size. This AD requires removal and replacement of the LPT stage 4 and stage 5 disks. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective April 8, 2025. The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of April 8, 2025. ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2024-2424; 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, 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 CFM material identified in this AD, contact CFM, GE Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH 45215; phone: (877) 432-3272; email:aviation.fleetsupport@ge.com. • You may view this material 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 atregulations.gov under Docket No. FAA-2024-2424. FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7743; email: mehdi.lamnyi@faa.gov. 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 certain CFM Model LEAP-1A, LEAP-1B, and LEAP-1C engines. The NPRM published in the Federal Register on November 8, 2024 (89 FR 88681). The NPRM was prompted by a report of a quality escape on LPT disks made from forgings with nonconforming material grain size on certain CFM Model LEAP-1A and LEAP-1B engines. The supplier assessed the duplex micro-structure using an arithmetic average grain size instead of considering the coarsest grain size. After a re-check of all forgings, the supplier has identified a number of parts with a coarse grain size that is below the drawing requirement. In the NPRM, the FAA proposed to require removal and replacement of the LPT stage 4 and stage 5 disks at the next piece-part exposure or before exceeding between 2,400 and 19,000 cycles since new, depending on the applicable thres…

Fonte: Federal Register (federalregister.gov). Texto original em inglês. Conteúdo sanitizado por segurança.