AD 2021-05-51 Prompted By The In-Flight Failure Of A 1st-Stage Low-Pressure Compressor (LPC) Blade On A PW4077

The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 model turbofan engines.

This AD was prompted by the in-flight failure of a 1st-stage low-pressure compressor (LPC) blade on a PW4077 model turbofan engine resulting in an engine fire during flight. This AD requires performing a thermal acoustic image (TAI) inspection for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. The FAA previously sent an emergency AD to all known U.S. owners and operators of these engines and is now issuing this AD to address the unsafe  condition on these products. This AD is effective March 24, 2021. Emergency AD 2021-05-51, issued on February 23, 2021, which contained the requirements of this amendment, was effective with actual notice.

Supplementary Information: On February 23, 2021, the FAA issued Emergency AD 2021-05-51 (the emergency AD), which requires performing a TAI inspection for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. The FAA sent the emergency AD to all known U.S. owners and operators of these engines. That action was prompted by the in-flight failure of a 1st-stage LPC blade on a PW4077 model turbofan engine resulting in an engine fire during flight. This condition, if not addressed, could result in 1st-stage LPC blade release, damage to the engine, and damage to the airplane.

FMI: www.regulations.gov