The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters undergoing final development and testing for the United States and partner nations. The fifth generation combat aircraft is designed to perform ground attack and air defense missions. The F-35 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. On 31 July 2015, the first squadron of F-35B fighters was declared ready for deployment after intensive testing by the United States Marines.
On 2 August 2016, the U.S. Air Force declared its first squadron of F-35A fighters as combat-ready. The F-35 is descended from the X-35, which was the winning design of the Joint Strike Fighter (JSF) program. It is being designed and built by an aerospace industry team led by Lockheed Martin. Other major F-35 industry partners include Northrop Grumman, Pratt & Whitney and BAE Systems. The F-35 took its first flight on 15 December 2006. The United States plans to buy 2,457 aircraft. The F-35 variants are intended to provide the bulk of the manned tactical airpower of the U.S. Air Force, Navy and the Marine Corps over the coming decades. Deliveries of the F-35 for the U.S. military are scheduled to be completed in 2037 with a projected service life up to 2070.