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 in a pusher configuration, that could not lift the aircraft. His second design called the S-2 was powered by a 25 hp Anzani engine in a tractor configuration and first flew on June 3, 1910 at a height of a few feet. On June 30 after some modifications, Sikorsky reached an altitude of "sixty or eighty feet" before the S-2 stalled and was completely destroyed when it crashed in a ravine. Later, Sikorsky built the two-seat S-5, his first design not based on other European aircraft. Flying this original aircraft, Sikorsky earned his pilot license; Fédération Aéronautique Internationale (FAI) license