The Sikorsky S-76 is a medium-size commercial utility helicopter designed and produced by the American helicopter manufacturer Sikorsky Aircraft. It is the company's first helicopter specifically developed for the civilian market. The S-76 was developed during the mid-1970s, originally being designated S-74 but renamed in honor of the U.S. Bicentennial. Drawing upon its recently-developed S-70 helicopter, it features twin turboshaft engines, four-bladed main and tail rotors, and retractable landing gear. On , the prototype performed its maiden flight. The initial production variant was the S-76A, the first deliveries of which took place on . Several improved models were produced over time, including the S-76 Mk II launched in 1982, and the S-76B in 1987. Development of the S-76D was particularly troubled, being delayed by four years of delays due to flight envelope issues; it was finally certified for operation on . The S-76 initially encountered strong demand from the off-shore oil drilling industry; later on, demand shifted towards the VIP sector of the market. It performed several noteworthy flights, such as the first circumnavigation of the world in an east-to-west direction by a helicopter, and an autonomous demonstration flight during 2016. Sikorsky also used individual helicopters, often heavily modified for the purpose, for experimental purposes and to support other programmes. Demand for the S-76 waned during the 2010s, newer helicopters such as the AgustaWestland AW139 proved to be stiff competition. During March 2022, Sikorsky halted new orders for the S-76, but stated that it was looking at opportunities for future overseas manufacturing with foreign partners. Development The development of the S-76 commenced during the mid-1970s as the S-74. The S-74 was subsequently redesignated the S-76 in honor of the U.S. Bicentennial. The company had set the design goal of producing a medium helicopter suitable for corporate transportation and the oil drilling industry. Sikorsky's design work on the S-70 helicopter (which was selected for use by the United States Army as the UH-60 Black Hawk) was utilized in the development of the S-76, incorporating S-70 design technology in its rotor blades and rotor heads. It was the first Sikorsky helicopter designed purely for commercial rather than military use. On , the prototype performed its maiden flight. On , initial US Federal Aviation Administration type certification was granted, while the first customer delivery took place on . During late 1978, the S-76 was officially named "Spirit", however, this name was officially dropped