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
Sikorsky S-29-A Sikorsky S-29-A The Sikorsky S-29-A was a twin-engine biplane airliner, first flown in 1924. It was the first aircraft that aviation pioneer Igor Sikorsky designed and built after coming to the United States, hence the special "-A" suffix signifying "America". The pilot and mechanic sat in an open cockpit between the upper wing and the tail, while up to 16 passengers were accommodated within the streamlined fuselage. With the airline industry only just emerging in the United States at that time, the S-29 failed to attract the customers that Sikorsky had hoped. It was eventually sold, however, and had a