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-16 Sikorsky S-16 The Sikorsky S-16, or RBVZ S-XVI (named after its manufacturer), was a Russian equi-span single-bay two-seat biplane designed by Igor Sikorsky in 1914-15. Conceived in response to demand for an escort fighter for the Ilya Muromets bombers, it was noteworthy in that it was one of the first aircraft to possess synchronisation gear for its 7.7 mm machine gun. The first S-XVI was completed on 6 February 1915 with an 80 hp engine instead of the intended 100 hp because of supply problems. On 17 December 1915, the Russian government placed an order for 18 aircraft, these being