FAA-2025-22344

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-2025-0474; Project Identifier AD-2024-00777-T; Amendment 39-23186; AD 2025-23-03] • RIN 2120-AA64 ( printed page 56986) AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. This AD was prompted by reports of precoolers that failed due to a wear-out condition, combined with latently failed overheat detection thermal switches. This AD requires an inspection for heat damage on the engine strut structure, repetitive tests of the thermal switch temperature and ground wires, replacement of the precooler on Model 757-300 airplanes, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective January 13, 2026. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 13, 2026. ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-0474; 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 Boeing material identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110 SK57, Seal Beach, CA 90740-5600; telephone 562-797-1717; websitemyboeingfleet.com. • You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available atregulations.gov under Docket No. FAA-2025-0474. FOR FURTHER INFORMATION CONTACT: Kathryn Hill, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3626; email: Kathryn.A.Hill@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 The Boeing Company Model 757 airplanes. The NPRM was published in the Federal Register on April 1, 2025 (90 FR 14346). The NPRM was prompted by reports of precoolers that failed due to a wear-out condition, combined with latently failed overheat detection thermal switches. In the NPRM, the FAA proposed to require an inspection for heat damage on the engine strut structure, repetitive tests of the thermal switch temperature and ground wires, replacement of the precooler on Model 757-300 airplanes, and applicable on-condition actions. The FAA is issuing this AD to address the combination of a failed precooler and latently failed overheat detection thermal switches. The unsafe…

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