The SR.N4 hovercraft was a large passenger and vehicle carrying hovercraft built by the British Hovercraft Corporation (BHC). BHC was formed by the merger of Saunders-Roe and Vickers Supermarine in 1966. Work on the SR.N4 began in 1965 and the first trials took place in early 1968. Power was provided by four Rolls-Royce Proteus marine turboshaft engines each driving its own lift fan and pylon-mounted steerable propulsion propeller.