Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

The FAA is superseding Airworthiness Directive (AD) 2019-03-01 and AD 2021-05-51 for certain Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 model turbofan engines. AD 2019-03-01 required performing initial and repetitive thermal acoustic image (TAI) inspections for cracks in certain 1st- stage low-pressure compressor (LPC) blades and removal of those blades that fail inspection. AD 2021-05-51 required performing a one-time TAI inspection for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. This AD was prompted by three in- flight failures of a 1st-stage LPC blade, with one failure resulting in an engine fire during flight, and subsequent manufacturer publication of service information specifying improved inspections for three critical locations on the 1st-stage LPC blade. This AD requires initial and repetitive ultrasonic (UT) inspections and TAI inspections for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. The FAA is issuing this AD to address the unsafe condition on these products.