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 (crater) named after Igor Sikorsky, a Russian-American aviation pioneer. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Sikorsky. Sikorsky (crater) Sikorsky is a crater on the far side of the Moon. It is situated behind the southeastern limb of the Moon, just out of sight from the Earth. It lies to the northwest of the huge walled plain Schrödinger. To the northwest is the smaller crater Moulton. In 1967 the Lunar Orbiter 4 photographed this region in high resolution, discovering a 310-km-long gouge cutting through