Sikorsky S-72 Sikorsky S-72 The Sikorsky S-72 was an experimental hybrid helicopter/fixed-wing aircraft developed by helicopter manufacturer Sikorsky Aircraft. The Rotor Systems Research Aircraft (RSRA) was developed by Sikorsky for NASA and the Army. The RSRA was developed to allow the inflight measurement of helicopter rotor characteristics. The airframe was developed using an existing Sikorsky S-61 main rotor, an S-61 roller gearbox, and a highly modified Sikorsky S-67 airframe. The RSRA could be fitted with TF34 turbofans and wings to allow compound helicopter configurations to be experimentally investigated at speeds up to . In addition, it could fly as a fixed-wing aircraft
Igor Sikorsky war-torn Europe, and particularly Russia, ravaged by the October Revolution and Civil War, he immigrated to the United States, arriving in New York on March 30, 1919. In the U.S., Sikorsky first worked as a school teacher and a lecturer, while looking for an opportunity to work in the aviation industry. In 1932, he joined the faculty of the University of Rhode Island to form an aeronautical engineering program and remained with the university until 1948. He also lectured at the University of Bridgeport. In 1923, Sikorsky formed the Sikorsky Manufacturing Company in Roosevelt, New York. He was helped by