Airworthiness Directives; Sikorsky Aircraft Corporation Model S-92A Helicopters

This amendment adopts a new airworthiness directive (AD) for the Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This action requires replacing a certain part-numbered tail gear box output housing that has 600 or more hours time-in-service (TIS) with an airworthy part. Also, this AD revises the Airworthiness Limitations section of the maintenance manual by reducing the life limit of the tail gear box output housing. This amendment is prompted by the premature failure of the tail gear box output housing during fatigue testing by the manufacturer. The actions specified in this AD are intended to prevent fatigue failure of the tail gear box output housing, loss of tail rotor drive, and subsequent loss of control of the helicopter.