Airworthiness Directives; Sikorsky Aircraft Corporation Model S76A, B, and C Helicopters

This amendment adopts a new airworthiness directive (AD) for the specified Sikorsky Aircraft Corporation (Sikorsky) model helicopters that requires removing non-conforming main landing gear brake discs (discs) and replacing them with different part-numbered airworthy discs. It also requires revising the Rotorcraft Flight Manual (RFM) to adjust takeoff and landing distances until the discs are replaced. This amendment is prompted by the manufacture of some discs using inferior materials. The actions specified by this AD are intended to prevent reduced braking performance and subsequent loss of control of the helicopter.