Igor Sikorsky being used in most helicopters produced today. Igor Sikorsky was also on the board of directors for the Tolstoy Foundation Center in Valley Cottage, New York. 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 after the October Revolution. In 1923, Sikorsky's sisters immigrated to the US, 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 died at his home in Easton, Connecticut, on
Sikorsky S-20 because it was viewed as inferior to newer enemy aircraft, and no series production was undertaken. As such, only five aircraft were ever produced. Sikorsky S-20 The Sikorsky S-20 (named after its designer) or RBVZ S-XX (named after its manufacturer) was a Russian single-bay unequal span two-seat biplane designed by Igor Sikorsky in 1916. Displaying some Nieuport influence, it saw very little service during World War I. Five S-XX aircraft were built in September 1916, with the first two powered by the 100 hp Gnome rotary engine which had powered its predecessor, the RBVZ S-XVI. However, the other three were