Superseded. This AD was superseded by AD 2021-22-14. Verify which one applies to your serial and effectivity before any maintenance action.
AD 2021-05-16
Effective 05/07/2021 · Published 04/02/2021
Airworthiness Directives; Pratt & Whitney Division Turbofan Engines
Summary
The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4164, PW4164-1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model turbofan engines. This AD was prompted by several reports of low-pressure turbine (LPT) 4th- stage vane cluster assemblies leaning back and notching into the rotating LPT 4th-stage blades, causing some blades to fracture and release. This AD requ…