Igor Sikorsky On June 27, 1931, Sikorsky filed for a patent for another "direct lift aircraft", and was awarded patent No. 1,994,488 on March 19, 1935. His design plans eventually culminated in the first (tethered) flight of the Vought-Sikorsky VS-300 on September 14, 1939, with the first free flight occurring eight months later on May 24, 1940. Sikorsky's success with the VS-300 led to the R-4, which became the world's first mass-produced helicopter, in 1942. Sikorsky's final VS-300 rotor configuration, comprising a single main rotor and a single antitorque tail rotor, has proven to be one of the most popular helicopter configurations,
Sikorsky S-11 Sikorsky S-11 The Sikorsky S-11 " Polukroogly " (Half Round) was a Russian single engine prototype reconnaissance aircraft completed in July 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division. The S-11 was a two seat mid-wing monoplane with wire-braced wings powered by a Gnome Monosoupape air-cooled rotary engine rated at . It was smaller and lighter than the S-7 on which it was based, and had a conventional wooden fuselage. The cockpit featured side-by-side seating with controls for the pilot only on the left. Originally built with ailerons