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 Kyiv Polytechnic Institute Igor Sikorsky Kyiv Polytechnic Institute The National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" (NTUU "KPI") is a major university in Kiev, Ukraine. In January 2012 Webometrics Ranking KPI made it into top 1,000 – taking 957th place out of 20,300 universities, 510th (February 2013). The institute was founded on 31 August 1898 as the Kiev Polytechnic Institute of Emperor Alexander II, but its current building complex was not built until 1902. Until then, the institute was renting out its space at the building of Commercial School located on Vorovsky Street. At that time it had four departments: