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
Igor Sikorsky in a pusher configuration, that could not lift the aircraft. His second design called the S-2 was powered by a 25 hp Anzani engine in a tractor configuration and first flew on June 3, 1910 at a height of a few feet. On June 30 after some modifications, Sikorsky reached an altitude of "sixty or eighty feet" before the S-2 stalled and was completely destroyed when it crashed in a ravine. Later, Sikorsky built the two-seat S-5, his first design not based on other European aircraft. Flying this original aircraft, Sikorsky earned his pilot license; Fédération Aéronautique Internationale (FAI) license