2022-22061

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-2022-0467; Project Identifier AD-2022-00174-E; Amendment 39-22196; AD 2022-20-12] • RIN 2120-AA64 AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) GEnx-1B and GEnx-2B model turbofan engines. This AD was prompted by the detection of melt-related freckles in the forgings and billets, which may reduce the life of certain compressor discharge pressure (CDP) seals, interstage seals, high-pressure turbine (HPT) rotor stage 2 disks, and stages 6-10 compressor rotor spools. This AD requires revising the airworthiness limitations section (ALS) of the applicable GEnx-1B and GEnx-2B Engine Manual (EM) and the operator's existing approved maintenance program or inspection program, as applicable, to incorporate reduced life limits for these parts. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective November 16, 2022. ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov by searching for and locating Docket No. FAA-2022-0467; 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. FOR FURTHER INFORMATION CONTACT: Alexei Marqueen, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781) 238-7178; email: Alexei.T.Marqueen@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 GE GEnx-1B54/P2, GEnx-1B58/P2, GEnx-1B64/P2, GEnx-1B67/P2, GEnx-1B70/P2, GEnx-1B70C/P2, GEnx-1B70/72/P2, GEnx-1B70/75/P2, GEnx-1B74/75/P2, GEnx-1B75/P2, GEnx-1B76/P2, GEnx-1B76A/P2, and GEnx-1B78/P2 (GEnx-1B) and GEnx-2B67, GEnx-2B67B, and GEnx-2B67/P (GEnx-2B) model turbofan engines. The NPRM published in the Federal Register on June 1, 2022 (87 FR 33071). The NPRM was prompted by the engine manufacturer notifying the FAA of the detection of melt-related freckles in the forgings and billets, which may reduce the life of certain CDP seals, interstage seals, HPT rotor stage 2 disks, and stages 6-10 compressor rotor spools (life-limited parts (LLPs)). The manufacturer's investigation determined that, as a result of such freckles forming in the forgings and billets, certain LLPs may have undetected subsurface anomalies that developed during the manufacturing process, resulting in reduced material properties and a lower fatigue life capability. Reduced material properties may cause premature LLP fracture, which could result in uncontained debris release. As a result of its investigation, the manufacturer determined the need to reduce the life limits of certain LLPs. To reflect these reduced life limits, the manufacturer revised the ALS of the affected GEnx-1B and GEnx-2B EMs. In the NPRM, the FAA proposed to require operators to update the…

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