Airworthiness Directives; Pratt & Whitney RTX Corporation (Type Certificate Previously Held by Pratt & Whitney Division United Technologies Corporation) Engines
Key claim: The FAA proposes to replace a recent safety order on certain Pratt & Whitney PW4000-series jet engines so operators must keep inspecting specified compressor and turbine parts for cracks and replace them if needed, after the earlier order left out a part number and misstated which engines could stop the inspections.
Abstract
(Proposed Rule · Transportation Department, Federal Aviation Administration) 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.
Why this matters
Airworthiness directives occasionally need corrective supersedures when the original rule misses a part number or misstates which engines can stop inspecting. This proposal keeps PW4000-series operators on the same inspection regime while closing a gap that could have let defective parts escape oversight. It is a routine but illustrative example of how FAA iterates on engine ADs after errors are identified.