Airworthiness Directive · Amendment 39-9226 · Sikorsky Aircraft Corporation Helicopters
Sikorsky Aircraft Corporation Helicopters
This AD applies to Sikorsky Aircraft Corporation S-58A, S-58B, S-58BT, S-58C, S-58D, S-58DT, S-58E, S-58ET, S-58F, S-58FT, S-58G, S-58H, S-58HT, S-58J, 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 adopts a new airworthiness directive (AD), applicable to Sikorsky Aircraft Model S-58 and S-58T series helicopters, that requires the removal and replacement of the transmission main gear box ring gear (ring gear) within certain time intervals, and establishes a retirement life for the ring gear. This amendment is prompted by reports of failures of the ring gear due to slow-growth fatigue cracks. The actions specified by this AD are intended to prevent failure of the ring gear, failure of the main transmission, 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.
Aircraft
