The Sikorsky Aircraft Corporation is an American aircraft manufacturer, a business unit of United Technologies Corporation, and is based in Stratford, Connecticut. Founded in 1925 by Igor Sikorsky, the company began production of aircraft in Roosevelt, New York, in that same year. Sikorsky moved to its current headquarters in 1929 and became part UTC (named United Aircraft and Transport Corporation at the time) in July of that year. In the United States, Sikorsky largely concentrated on the development of multi-engined landplanes, and then on amphibious aircraft. Sikorsky merged with Vought Aircraft and began development on helicopters. Sikorsky remains one of the leading manufacturers of helicopters to this day.