Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Résumé

We are adopting a new airworthiness directive (AD) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-76C helicopters. This AD requires installing an improved throttle stop and a wider trigger on the engine control levers (ECL). This AD was prompted by a bird-strike to the windshield that resulted in unintended movement of the engine control levers from the forward position and towards the flight-idle position, which reduced power on both engines. These actions are intended to prevent unintended movement of the ECLs, resulting in main rotor speed decay and subsequent loss of control of the aircraft.