sentences:  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 in July 1984.