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.

The S-75 mated an entirely new composite airframe with the twin turboshaft engines, transmission, and main and tail rotors of Sikorsky's S-76A civil transport helicopter.

[1] The S-75's floors, roof and most exterior surfaces were of more ballistically-resistant Kevlar, while most of the aircraft's basic load-bearing structure was built of graphite or a graphite/epoxy blend.

The machine was equipped with specially designed impact-resistant crew and passenger seats and high-strength pneumatic shock absorbers on its fixed tricycle landing gear, in keeping with the Army's requirement that the ACAP aircraft meet or exceed all existing military crashworthiness standards.

The S-75 underwent a 50-hour evaluation by the Army, and was found to have exceeded the weight- and cost-saving criteria set in the original ACAP specification.