Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2026-09-02, which applies to certain Pratt & Whitney RTX Corporation (PW) Model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 engines. AD 2026-09-02 requires repetitive angle ultrasonic scan inspections (AUSIs) of the high-pressure compressor (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. Since the FAA issued AD 2026-09-02, the FAA was notified that a certain part number was omitted from AD 2026-09-02 and the applicability of the optional terminating action was matched to an unrelated requirement. This proposed AD would require repetitive AUSIs of the HPC 15th-stage disks, front turbine hubs, 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 proposing this AD to address the unsafe condition on these products.