The Lockheed Martin F-35 Lightning II is a single-seat, single-engine, stealth-capable military strike fighter, a multi-role aircraft that can perform close air support, tactical bombing, and air-to-air combat. The F-35 is descended from the X-35 of the Joint Strike Fighter (JSF) program. Its development is being principally funded by the United States with the United Kingdom and other partner governments providing additional funding. It is being designed and built by an aerospace industry team led by Lockheed Martin with Northrop Grumman and BAE Systems as major partners. Demonstrator aircraft flew in 2000, with the production model first flying on 15 December 2006.