Changes

In 1928, Sikorsky became a naturalized citizen of the United States. The Sikorsky Manufacturing Company moved to Stratford, [[Connecticut]] in 1929. It became a part of the United Aircraft and Transport Corporation (now United Technologies Corporation) in July of that year. The company manufactured flying boats, such as the S-42 "Clipper", used by Pan Am for transatlantic flights.

In 1928, Sikorsky became a naturalized citizen of the United States. The Sikorsky Manufacturing Company moved to Stratford, [[Connecticut]] in 1929. It became a part of the United Aircraft and Transport Corporation (now United Technologies Corporation) in July of that year. The company manufactured flying boats, such as the S-42 "Clipper", used by Pan Am for transatlantic flights.

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, being used in most helicopters produced today.

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. The helicopter continued testing throughout [[World War II]] and did not see action until the [[Korean War]] in the early 1950s. 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, being used in most helicopters produced today.

Sikorsky was married to Olga Fyodorovna Simkovitch in the Russian Empire. They were divorced and Olga remained in Russia with their daughter, Tania, as Sikorsky departed following the [[Bolshevik Revolution]] in 1917. In 1923, Sikorsky's sisters immigrated to the U.S., bringing six-year-old Tania with them. Sikorsky married Elisabeth Semion (1903–1995) in 1924, in [[New York]]. Sikorsky and Elisabeth had four sons; Sergei, Nikolai, Igor Jr. and George.

Sikorsky was married to Olga Fyodorovna Simkovitch in the Russian Empire. They were divorced and Olga remained in Russia with their daughter, Tania, as Sikorsky departed following the [[Bolshevik Revolution]] in 1917. In 1923, Sikorsky's sisters immigrated to the U.S., bringing six-year-old Tania with them. Sikorsky married Elisabeth Semion (1903–1995) in 1924, in [[New York]]. Sikorsky and Elisabeth had four sons; Sergei, Nikolai, Igor Jr. and George.