Vought-Sikorsky VS-300 Vought-Sikorsky VS-300 The Vought-Sikorsky VS-300 (or S-46) is a single-engine helicopter designed by Igor Sikorsky. It had a single three-blade rotor originally powered by a 75 horsepower (56 kW) engine. The first "free" flight of the VS-300 was on 13 May 1940. The VS-300 was the first successful single lifting rotor helicopter in the United States and the first successful helicopter to use a single vertical-plane tail rotor configuration for antitorque. With floats attached, it became the first practical amphibious helicopter. Igor Sikorsky's quest for a practical helicopter began in 1938, when as the Engineering Manager of the Vought-Sikorsky Division
Sikorsky S-20 because it was viewed as inferior to newer enemy aircraft, and no series production was undertaken. As such, only five aircraft were ever produced. Sikorsky S-20 The Sikorsky S-20 (named after its designer) or RBVZ S-XX (named after its manufacturer) was a Russian single-bay unequal span two-seat biplane designed by Igor Sikorsky in 1916. Displaying some Nieuport influence, it saw very little service during World War I. Five S-XX aircraft were built in September 1916, with the first two powered by the 100 hp Gnome rotary engine which had powered its predecessor, the RBVZ S-XVI. However, the other three were