RS-1

The Sikorsky RS‑1 was an early American rotorcraft developed in the late 1920s as a single‑seat, single‑rotor experimental helicopter. Conceived by Igor Sikorsky while he headed the Sikorsky Aircraft Corporation, the RS‑1 built upon the lessons learned from the earlier VS‑300 prototype. First flown in 1929 at the company's Stratford, Connecticut facility, the machine featured a simple open framework, a 75‑horsepower radial engine mounted behind the pilot, and a two‑bladed wooden rotor with a cyclic pitch control system. Its lightweight design allowed it to achieve a modest 45‑mile‑per‑hour cruise and a maximum altitude of roughly 500 feet, enough to demonstrate controlled hover, forward flight, and autorotation recovery. Although only a single RS‑1 was constructed, the aircraft proved the viability of the coaxial control mechanisms that would become standard in later Sikorsky models. The RS‑1’s successful flights convinced the United States Army Air Corps to fund further development, leading directly to the production of the R‑4, the world’s first mass‑produced helicopter. Consequently, the RS‑1 occupies a pivotal place in aviation history as the bridge between experimental prototypes and operational rotorcraft. Its legacy endures in modern rotorcraft engineering.