Airworthiness Directives; Pratt & Whitney RTX Corporation (Type Certificate Previously Held by Pratt & Whitney Division United Technologies Corporation) Engines

The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney RTX Corporation (PW) Model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 engines. This AD was prompted by an analysis of an event involving an International Aero Engines, LLC (IAE LLC) Model PW1127GA-JM engine, which experienced a high-pressure compressor (HPC) 7th-stage integrally bladed rotor (IBR- 7) separation that resulted in an aborted takeoff. This AD requires repetitive angle ultrasonic scan inspections (AUSIs) of the HPC 15th- stage disks, front turbine hubs, high pressure turbine (HPT) 1st-stage air seals, and HPT 2nd-stage hubs for crack indications, and removal from service and replacement if necessary, and for certain serial numbers, removal from service and replacement of the HPT 1st-stage air seal. The FAA is issuing this AD to address the unsafe condition on these products.