Sikorsky S-72

The Sikorsky S‑72, built by Sikorsky Aircraft Corporation in the late 1970s, was a pioneering research helicopter that explored the concept of compound‑helicopter flight. Developed as a follow‑on to the earlier S‑61 program, the S‑72 first flew on 12 May 1978 from Stratford, Connecticut, and served as the testbed for a new propulsion arrangement that combined a conventional main rotor with a rear‑mounted pusher propeller and auxiliary lift surfaces. Its key features included a rigid three‑blade main rotor, a turbofan‑derived pusher engine delivering 1,200 shaft horsepower, and a slender fuselage equipped with small forward‑swept wings to generate additional lift at high speed. The aircraft achieved a maximum speed of 210 knots, more than twice the cruise speed of contemporary utility helicopters, and demonstrated stable handling in the transition between hover and forward flight. Though only one prototype was built, the S‑72’s technology directly influenced later Sikorsky programs such as the X‑2 and the S‑97 Raider, establishing the foundation for modern high‑speed compound rotorcraft. Its legacy endures as a critical stepping stone that reshaped expectations for rotary‑wing performance and opened new possibilities for rapid, long‑range vertical‑lift operations.

Sikorsky Aircraft Corporation

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