Summary
We propose to adopt a new airworthiness directive (AD) for certain serial number GE Aviation Czech s.r.o. M601E-11, M601E-11A, and M601F turboprop engines. This proposed AD was prompted by the determination that wear or cracking, and subsequent misalignment of the quill shaft of the engine and the power turbine (PT) shaft, may lead to rupture of the quill shaft, overspeed of the PT, and uncontained engine failure. This proposed AD would require inspection of the reduction gearbox and supporting cone. We are proposing this AD to prevent misalignment and rupture of the quill shaft, which could lead to overspeed of the PT, uncontained engine failure, and damage to the airplane.