Summary
The FAA proposes to adopt a new airworthiness directive (AD) for PW models JT9D-7, -7A, -7AH, -7H, -7F, and -7J turbofan engines. This proposed AD would require initial and repetitive borescope inspections of the 2nd stage high-pressure turbine (HPT) rotor and stator assembly. This proposed AD results from an uncontained failure of a 2nd stage HPT rotor disk that caused the engine to separate from the airplane. We are proposing this AD to prevent failure of the 2nd stage HPT rotor disk, which could result in uncontained engine failure, damage to the airplane, and the engine separating from the airplane.