The F-20 Tigershark (initially F-5G) was a privately financed light fighter, designed and built by Northrop. Its development began in 1975 as a further evolution of Northrop’s F-5E Tiger II, featuring a new engine that greatly improved overall performance, and a modern avionics suite including a powerful and flexible radar. Compared with the F-5E, the F-20 was much faster, gained beyond visual range air-to-air capability, and had a full suite of air-to-ground modes capable of firing most U.S. weapons. With these improved capabilities, the F-20 became competitive with contemporary U.S. fighter designs like the F-16 Fighting Falcon, but was much less expensive to purchase and operate.
Much of the F-20’s development was carried out as part of a U.S. Department of Defense (DoD) project called “FX”, which intended to sell less-advanced fighter designs to U.S. allies to limit the possibility of front-line U.S. technology falling into Soviet hands. FX developed out of a general re-working of U.S. military export policy started under the Carter administration in 1977. Although Northrop had high hopes for the F-20 in the international market, changes in policy following Ronald Reagan’s election left the F-20 competing for sales with front line fighters like the F-16. No F-20 orders were ever placed, and the development program was eventually abandoned in 1986 after three prototypes had been built and a fourth partially completed.