2022-28091

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-2022-1306; Project Identifier AD-2022-01040-E; Amendment 39-22289; AD 2022-27-04] • RIN 2120-AA64 AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all Pratt & Whitney (PW) PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-3, PW1525G, and PW1525G-3 model turbofan engines. This AD was prompted by an uncommanded dual engine shutdown upon landing, resulting in compromised braking capability due to the loss of engine power and hydraulic systems. This AD requires removal from service of certain electronic engine control (EEC) full authority digital engine control (FADEC) software versions and replacement with updated software. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective January 31, 2023. ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov by searching for and locating Docket No. FAA-2022-1306; 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: Mark Taylor, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781) 238-7229; email: Mark.Taylor@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 all PW PW1519G, PW1521G, PW1521G-3, PW1521GA, PW1524G, PW1524G-3, PW1525G, and PW1525G-3 model turbofan engines. The NPRM published in the Federal Register on October 25, 2022 (87 FR 64397). The NPRM was prompted by a report that an airplane experienced an uncommanded dual engine shutdown upon landing, resulting in compromised braking capability due to the loss of engine power and hydraulic systems. A subsequent investigation determined that the sequence of the auto-throttle increasing throttle to maintain Mach number, immediately followed by pilot command to decrease throttle to idle, caused a transient disagreement between actual and commanded thrust. This disagreement triggered the thrust control malfunction (TCM) detection logic and resulted in dual engine shutdown once the weight on wheels signal was activated upon landing. The installed EEC FADEC software version latches the fault and allows the engine to continue operation as commanded but shuts down the engine upon landing. The manufacturer identified the situations that could trigger the TCM logic erroneously and updated the EEC FADEC software. This software update makes corrective improvements to the TCM logic, including revised criteria for triggering the TCM logic and establishing criteria that permit the TCM logic to unlatch during flight. In the NPRM, the FAA proposed to require removal from service of certain EEC FADEC software versions and replacement with a software version eligible for installation. The FAA is issuing this AD to address the unsafe condi…

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