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
Sikorsky Russky Vityaz Sikorsky Russky Vityaz The Sikorsky Russky Vityaz (), or Russian Knight, previously known as the Bolshoi Baltisky () "(The Great Baltic)" in its first four-engined version, was the first four-engine aircraft in the world, designed by Igor Sikorsky and built at the Russian Baltic Railroad Car Works ("Russo-Baltiiskyi Vagonnyi Zavod" or "R-BVZ") in Saint Petersburg in early 1913. Sikorsky conceived the S-21 design in 1911, when no known aircraft could lift more than . The carrying capacity record belonged to the French pilot Ducis, who had flown with a load of . On hearing about the construction of the "Russky