Airworthiness Directive · Amendment 39-11036 · McDonnell Douglas Helicopter Systems Model 369D, 369E, 369FF, 369H, MD500N, and MD600N Helicopters
McDonnell Douglas Helicopter Systems Model 369D, 369E, 369FF, 369H, MD500N, and MD600N Helicopters
Model 369D, 369E, 369FF, 369H, MD500N, and MD600N helicopters, with input shaft coupling assemblies, part number (P/N) 369F5133-1, serial number (S/N) 030829-0126 through 030829-0207, installed on main transmission, P/N 369F5100-503, and on overrunning clutch, P/N 369F5450, certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to McDonnell Douglas Helicopter Systems (MDHS) Model 369D, 369E, 369FF, 369H, MD500N, and MD600N helicopters, that requires a one- time visual inspection of certain input shaft coupling assemblies for pitting. This amendment is prompted by three operators' reports of discovering pitting on the internal spline teeth. The actions specified by this AD are intended to prevent failure of the spline teeth in the input shaft coupling assembly, loss of drive to the main rotor system, and subsequent loss of control of the helicopter.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
