Sikorsky Aircraft and it became a part of [[United Aircraft and Transport Corporation]] (now [[United Technologies Corporation]]) in July of that year. [[File:Sikorsky Aircraft Corporation ad Model S-42 Clipper Flying Boat 1937.jpg|thumb|left|upright|Advertisement for [[Sikorsky S-42]] Clipper flying boat from 1937]] In the United States, Igor Sikorsky originally concentrated on the development of multi-engined landplanes and then amphibious aircraft. In the late 1930s, sales declined and United Aircraft merged his division with [[Vought Aircraft]]. He then began work on developing a practical helicopter. After first flying the [[VS-300]] he developed the [[Sikorsky R-4]], the first stable, single-rotor, fully controllable [[helicopter]] to enter full-scale
Sikorsky S-7 Sikorsky S-7 The Sikorsky S-7 was a Russian single engine experimental prototype aircraft built by the Russian Baltic Railroad Car Works shortly after Igor Sikorsky became chief engineer of the aircraft manufacturing division. The S-7 was two place wire-braced monoplane powered by a Gnome air-cooled rotary engine. Construction began in early summer of 1912 and completed in July. The pilot sat in the rear cockpit with a passenger seated in a forward compartment in a tandem arrangement. The fuselage was enclosed in plywood and the aircraft used components taken from the S-6A including the main wing, tail and landing gear.