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 Ilya Muromets washroom on board. During World War I, it became the first four-engine bomber to equip a dedicated strategic bombing unit. This heavy bomber was unrivaled in the early stages of the war, as the Central Powers had no aircraft capable enough to rival it until much later. The Ilya Muromets (Sikorsky S-22) was designed and constructed by Igor Sikorsky at the Russo-Baltic Carriage Factory (RBVZ) in Saint Petersburg in 1913. It was based on his earlier S-21 "Russky Vityaz", which started out as the twin-engined "Le Grand", then as the twin tandem-engined "Bolshoi Baltisky" before placing all four of the