FAA Issues Airworthiness Directive NPRM for Sikorsky S-92A

The FAA is proposing to adopt a new airworthiness directive for certain Sikorsky Model S-92A helicopters requiring the installation of 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 software that includes an aural annunciation of a complete oil pressure loss condition. The proposed 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.