Sikorsky S-75 Sikorsky S-75 The Sikorsky S-75 was a proof-of-concept all-composite helicopter. Sikorsky Aircraft used all-composite materials to replace metal to provide greater strength, lighter weight, lower manufacturing costs, and reduce maintenance costs. The Sikorsky S-75 was developed under the US Army's Advanced Composite Airframe Program (ACAP), the goal of which was the development of an all-composite helicopter fuselage, lighter and less costly to build than predominantly metal airframes in support of the Light Helicopter Experimental (LHX) program. In February 1981, contracts were awarded to Sikorsky and Bell Helicopter, with Bell submitting its Model D292. The S-75 flew for the first time
Sikorsky S-35 Sikorsky S-35 The Sikorsky S-35 was an American twin-engined sesquiplane transport later modified to use three-engines. It was designed and built by the Sikorsky Manufacturing Company for an attempt by Rene Fonck on a non-stop Atlantic crossing for the Orteig Prize. It was destroyed in the attempt. The S-35 was designed as a twin-engined transport with a range. During 1926 Rene Fonck, a French First World War fighter ace, was looking for a multi-engine aircraft to enter a competition to be the first to fly non-stop from New York to Paris. The prize was $25,000, offered by Raymond Orteig. Fonck