Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4000-94 inch and PW4000-100 inch model turbofan engines. This AD was prompted by a report of a crack found in the high-pressure compressor (HPC) 10th stage disk. This AD requires performing an ultrasonic inspection (USI) or an eddy current inspection (ECI) of the HPC 10th stage disk. We are issuing this AD to prevent failure of the HPC 10th stage disk, uncontained disk release, damage to the engine, and damage to the airplane.