The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engined, all-weather stealth multirole fighters. The fifth-generation combat aircraft is designed to perform ground-attack and air-superiority missions. It has three main models: the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short take-off and vertical-landing (STOVL) variant, and the F-35C carrier-based catapult-assisted take-off but arrested recovery (CATOBAR) variant. The F-35 descends from the Lockheed Martin X-35, the winning design of the Joint Strike Fighter (JSF) program. It is built by Lockheed and many subcontractors, including Northrop Grumman, Pratt & Whitney, and BAE Systems.