The Bell Aircraft Corporation was an aircraft manufacturer of the United States, a builder of several types of fighter aircraft for World War II but most famous for the Bell X-1, the first supersonic aircraft, and for the development and production of many important civilian and military helicopters. Bell also developed the Reaction Control System for the Mercury Spacecraft, the North American X-15 and the Bell Rocket Belt. The company was purchased in 1960 by Textron, and lives on today as Bell Helicopter.