Airworthiness Directives; McDonnell Douglas Helicopter Systems Model 369D, 369E, 369FF, 500N, AH-6, and MH-6 Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to McDonnell Douglas Helicopter Systems (MDHS) Model 369D, 369E, 369FF, 500N, AH-6 and MH-6 helicopters. This action requires visual inspections of the overrunning clutch retainer, carrier, housing, and pin for wear from spinning of the bearing outer race. This amendment is prompted by a report of inflight vibrations and subsequent investigations of three other overrunning clutches, which indicated wear of the bearing carrier due to spinning of the bearing outer race. The actions specified in this AD are intended to detect wear of other clutch components, excessive vibration which could lead to failure of the overrunning clutch, wear on the bearing carrier, and subsequent loss of power to the helicopter rotor drive system.