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-19 Sikorsky S-19 The Sikorsky S-19 was a Russian twin engine experimental prototype aircraft built late in 1916 by the Russian Baltic Railroad Car Works while Igor Sikorsky was chief engineer of the aircraft manufacturing division. The S-19 was a two bay sesquiplane powered by two Sunbeam Crusader water-cooled V-8 engines installed in push-pull configuration. Arranged as a twin-boom aircraft, it had a large rudder located in the center of the empenage. Two crewmembers occupied cockpits in the foreword most section of the booms in front of the lower wing and served as pilot and machine gunner. Flight testing revealed sluggish