Sikorsky X2 Sikorsky X2 The Sikorsky X2 is an experimental high-speed compound helicopter with coaxial rotors developed by Sikorsky Aircraft. Sikorsky developed the X2 helicopter on a $50 million budget. The design includes expertise gathered from several earlier design projects. The S-69/XH-59A Advancing Blade Concept Demonstrator had shown that high speed was possible with a coaxial helicopter with auxiliary propulsion (two jet engines), but that vibration and fuel consumption was excessive; the Cypher UAV expanded the company's knowledge of the unique aspects of coaxial flight control laws with a fly-by-wire aircraft; and the RAH-66 Comanche developed expertise in composite rotors and advanced
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