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-6 Sikorsky S-6 The Sikorsky S-6 was a Russian single engine experimental aircraft similar to the S-5, built in 1911 by Igor Sikorsky. Construction of the first S-6 was started in August 1911. The three bay biplane was powered by an Argus 4-cylinder water-cooled engine producing . Initial flight tests in late November were disappointing, revealing a long take-off run and poor climb performance. Sikorsky disassembled the aircraft and took it home where substantial modifications were undertaken, including lengthening the wingspan and reducing aerodynamic drag by enclosing the fuselage with wood veneer. Ailerons on the lower wing were removed and strut