Airworthiness Directives; Pratt & Whitney Engines
Key claim: The FAA proposes requiring operators of certain Pratt & Whitney engines to repeatedly inspect compressor rotors for wear from stator-vane contact and replace a bushing set, or remove affected engines from service.
Abstract
(Proposed Rule · Transportation Department, Federal Aviation Administration) The FAA proposes to adopt a new airworthiness directive (AD) for all Pratt & Whitney (PW) Model PW1519G, PW1521G, PW1521GA, PW1521G- 3, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1919G-RC, PW1921G, PW1921G-RC, PW1922G, PW1923G, and PW1923G-A engines with a certain high-pressure compressor (HPC) module installed. This proposed AD was prompted by six reports of clashing found on either the HPC 2nd stage rotor or 3rd stage rotor caused by contact with the corresponding HPC variable stator vanes (VSV). This proposed AD would require initial and repetitive borescope inspections (BSIs) of the HPC 1st stage, 2nd stage, and 3rd stage rotor rear rim surfaces for evidence of wear, scratching, or contact with the corresponding HPC VSV inner locating ring and, depending on the results, removal from service and replacement. This proposed AD would also require replacement of the HPC VSV bushing set as terminating action to the initial and repetitive BSIs of the HPC 1st stage, 2nd stage, and 3rd stage rotor rear rim surfaces. The FAA is proposing this AD to address the unsafe condition on these products.
Why this matters
Compressor rotor wear from stator-vane contact can progress to rotor failure and in-flight engine problems, so the FAA is codifying a recurring inspection and bushing-replacement regimen for the affected Pratt & Whitney models. The proposal continues a steady cadence of engine ADs targeting manufacturing-quality and wear issues on in-service turbine engines.