The Bell X-14 (Bell Type 68) was an experimental VTOL aircraft flown in the United States in the 1950s. The main objective of the project was to demonstrate horizontal and vertical takeoff, hover, transition to forward flight, and vertical landing.
Bell constructed the X-14 as an open-cockpit, all-metal monoplane. It was powered by two Armstrong Siddeley Viper turbojet engines equipped with thrust deflectors sited at the aircraft's centre of gravity. The engines are fixed in position; transition from vertical to horizontal flight is achieved with a system of movable vanes that control the direction of engine thrust. Top speed was 180 miles per hour with a service ceiling of 20,000 feet. The X-14 was designed using existing parts from two Beech aircraft: wings, ailerons, and landing gear of a Bonanza and the tailcone and empennage of a T-34.