Airworthiness Directive · Amendment 39-8935 · Sikorsky Aircraft Corporation Helicopters
Sikorsky Aircraft Corporation Helicopters
This AD applies to Sikorsky Aircraft Corporation S-58BT, S-58DT, S-58ET, S-58FT, S-58HT, S-58JT.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment supersedes an existing airworthiness directive (AD), applicable to Sikorsky Aircraft Model S-58T series helicopters, that currently requires a one-time inspection of the engine drive shaft assembly (drive shaft assembly) for cracks and loose balance weights. This amendment requires initial and repetitive visual and florescent penetrant inspections of the drive shaft assembly for cracks and improperly installed rivets. This amendment is prompted by three reported incidents of loose or missing drive shaft assembly balance weights and two reported incidents of fatigue cracks on the drive shaft assembly near the balance weight rivet hole. The actions specified by this AD are intended to prevent failure of the drive shaft assembly, loss of power to the rotor system, and a subsequent forced landing 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.
Aircraft
