The US Federal Aviation Administration has published a proposal in the Federal Register to replace Airworthiness Directive 2026-09-02, which covers certain Pratt & Whitney RTX Corporation PW4000-series engines, including the PW4074, PW4077, PW4084D and PW4090 models and their variants. The existing directive calls for repeated angle ultrasonic scan inspections of several rotating parts to look for cracks: high-pressure compressor 15th-stage disks, front turbine hubs, high-pressure turbine 1st-stage air seals and high-pressure turbine 2nd-stage hubs. Parts showing crack indications must be removed from service and replaced. The excerpt does not detail what the superseding directive would change.