Sikorsky S-72 RSRA

The first of two Sikorsky S-72 helicopters (NASA 545) developed under contract to NASA and the US Army made its maiden flight on 12 October 1976. Known as a rotor systems research aircraft (RSRA), these two machines are test-bed aircraft for a wide variety of rotor systems. Intended for a wide variety of rotor systems, both have turboshafts but can add fixed wings and turbofan engines to test rotors too small to support the helicopter in flight.