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-5 Sikorsky S-5 The Sikorsky S-5 was an early Russian single seat biplane design by Igor Sikorsky, completed in late April 1911. The S-5 was powered by a Argus water-cooled engine turning a propeller Sikorsky designed and built himself. The fabric covering the wooden wings was tightened with pure alcohol and glue mixed with boiling water while the fuselage structure was left exposed. Instead of separate levers to control the elevator and ailerons as in his previous aircraft, Sikorsky designed a single control lever with a wheel allowing control of pitch and roll. This "control column" included a button switch to