F-20 Tigershark was a privately financed fighter aircraft, designed and built by Northrop in the USA, starting in 1975. It was a further evolution of Northrop's F-5 Freedom Fighter (in fact it was originally designated F-5G), although ultimately it shared little more than a strong family resemblance to that aircraft. The main change was the replacement of the F-5's two General Electric J85 engines with a single F404 engine, increasing its total thrust by 60%. Like the F-5, however, it was designed as a low-cost, high-performance fighter plane that was easy to maintain. It could reach speeds of Mach 2 and had a range of 1880 nautical miles.
The F-20 made its first flight on August 30, 1982, and a total of three prototypes were created. It was intended for sale to foreign countries and militaries, but the market for the plane never developed, as President Ronald Reagan relaxed the restrictions on selling figthers such as the F-16 Fighting Falcon to other countries. After six years and no major buyers, Northrop cancelled the $1.2 billion project.
The last existing F-20 is on display at the California Science Center. The other two prototypes were lost due to crashes during world sales tours. The crashes were caused by pilot error, and were not linked to any malfunction of the planes.