Sikorsky S-76 ERASikorsky S 76 ERA Helicopter model. Increasing needs for transport helicopters to support offshore energy projects prompted Sikorsky to conduct global market research and identify operator requirements. In 1975, Sikorsky launched development of a 14 seat commercial helicopter, the Sikorsky S 76, later called Spirit. The first of four prototypes took flight on March 13, 1977. The enhanced S 76B features Pratt & Whitney PT6B 36 turboshaft engines, while