Summary
This document proposes the adoption of a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S76A, B, and C helicopters. The AD would require removing non-conforming main landing gear brake discs (discs) and replacing them with different part-numbered airworthy discs. It would also require revising the Rotorcraft Flight Manual (RFM) to adjust takeoff and landing distances until the discs are replaced. This proposal is prompted by the manufacture of some discs using inferior materials. The actions specified by the proposed AD are intended to prevent reduced braking performance and subsequent loss of control of the helicopter.