2022-13088

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-2022-0589; Project Identifier AD-2022-00376-E; Amendment 39-22084; AD 2022-12-12] • RIN 2120-AA64 AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for comments. SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4062 model turbofan engines. This AD was prompted by a report of a manufacturing quality escape due to insufficient cooling of the low-pressure turbine (LPT) stage 5 air seal resulting in a reduction of the low-cycle fatigue (LCF) life limit. This AD requires removal and replacement of the LPT stage 5 air seal with a part eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective July 5, 2022. The FAA must receive comments on this AD by August 1, 2022. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: (202) 493-2251. • Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Examining the AD Docket You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0589; 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 street address for Docket Operations is listed above. FOR FURTHER INFORMATION CONTACT: Carol Nguyen, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781) 238-7655; email: carol.nguyen@faa.gov. SUPPLEMENTARY INFORMATION: Background The FAA received a report from the manufacturer of a quality escape, resulting in a life reduction of the LPT stage 5 air seal installed on certain PW4062 model turbofan engines. Subsequent investigation by the manufacturer revealed that insufficient cooling after heat treatment resulted in non-conformance to the design specifications. This non-conformance lowers the LCF capability in a section of the LPT stage 5 air seal that already has an LCF life limit, resulting in a reduction in the LCF life limit from 15,000 cycles to 8,240 cycles. This condition, if not addressed, could result in the uncontained release of the LPT stage 5 air seal, damage to the engine, and damage to the airplane. The FAA is issuing this AD to address the unsafe condition on these products. FAA's Determination The FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. …

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