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 XP2S Sikorsky XP2S The Sikorsky XP2S was an American biplane patrol flying boat developed for the United States Navy during the early 1930s. After selling a small quantity of PS / RS patrol / transport amphibians to the Navy, Sikorsky (then a division of United Aircraft Corporation) endeavoured to interest the service in a patrol flying boat. Having received a development contract in mid-1930, Sikorsky delivered a complete aircraft for testing in June 1932. The XP2S-1, as the prototype was designated, was a two-bay, equal-span biplane of mixed construction. Its two R-1340 Wasp radial engines were mounted in a single nacelle