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-9 Sikorsky S-9 The Sikorsky S-9 "Kruglyj" (Rounded One) was a Russian single engine prototype aircraft completed in the spring of 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division. The S-9 was a three-seat mid-wing monoplane with constant-chord wire-braced wings originally powered by a Gnome air-cooled rotary engine rated at . It was the first monocoque monoplane built in Russia and the cylindrical tapered fuselage was constructed of plywood 5 mm thick in the forward section and 3mm thick aft. Construction was completed in the spring of 1913. Upon