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 Kiev Polytechnic Institute. After the academic year, Sikorsky again accompanied his father to Germany in the summer of 1908, where he learned of the accomplishments of the Wright brothers' Flyer and Ferdinand von Zeppelin's dirigible. Sikorsky later said about this event: "Within twenty-four hours, I decided to change my life's work. I would study aviation." By the start of World War I in 1914, Sikorsky's airplane research and production business in Kiev was flourishing, and his factory made bombers during the war. After the Bolshevik revolution began in 1917, Igor Sikorsky fled his homeland, because the new government threatened to