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
Igor Sikorsky No. 64 issued by the Imperial Aero Club of Russia in 1911. During a demonstration of the S-5, the engine quit and Sikorsky was forced to make a crash landing to avoid a wall. It was discovered that a mosquito in the gasoline had been drawn into the carburetor, starving the engine of fuel. The close call convinced Sikorsky of the need for an aircraft that could continue flying if it lost an engine. His next aircraft, the S-6 held three passengers and was selected as the winner of the Moscow aircraft exhibition held by the Russian Army in February