Airworthiness Directives; GKN Westland Helicopters Ltd., 30 Series Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to GKN Westland Helicopters Ltd. (Westland) 30 series helicopters. This action requires determining the total hours time-in- service (TIS) of the six tail rotor drive shafts (drive shafts), creating a component history card or an equivalent record for each shaft, and replacing those drive shafts that exceed a certain TIS with an airworthy drive shaft. This amendment is prompted by findings of drive shaft attachment flange cracks on similar British military model helicopters. This condition, if not corrected, could result in failure of the drive shaft coupling attachment flanges that could result in loss of power to the tail rotor and subsequent loss of control of the helicopter.