Airworthiness Directives; Pratt & Whitney Division (PW) Turbofan Engines
We are adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines. This AD was prompted by an in-flight failure of a 1st-stage low-pressure compressor (LPC) blade. This AD requires initial and repetitive thermal acoustic imaging (TAI) inspections for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. We are issuing this AD to address the unsafe condition on these products.