Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

We are adopting a new airworthiness directive (AD) for Sikorsky Model S-92A helicopters. This AD requires installing a main gearbox (MGB) failed pump sensor and vacuum switch wiring, installing an MGB oil auto bypass system, activating Aircraft Management System (AMS) 7.1 software to show a new visual warning, and installing updated enhanced ground proximity warning system (EGPWS) software that includes an aural annunciation of a complete oil pressure loss condition. This AD also requires inserting a Rotorcraft Flight Manual (RFM) Supplement into the applicable RFM. This AD was prompted by investigation results of in- service oil leakage incidents. The actions are intended to alert and prevent MGB oil loss, which could lead to failure of the MGB and subsequent loss of control of the helicopter.