The Northrop F-20 Tigershark was a related development of the F-5 Tiger, leading to the aircraft initially being designated as the F-6G.
In terms of performance, the Tigershark was inferior to the F-16 Fighting Falcon, so the US Air Force did not order the F-20 and the program was cancelled.
The design of the F-20 is based on the F-5, but this time an Electronic Flight Instrument System (EFIS) cockpit was included. To reduce unit and maintenance cost, it was equipped with only one General Electric F404-GE-100 engine, which is more powerful then the twin-engines of the F-5. Even if the two prototypes were lost, the F-20 has a reliability of 97 per-cent. The F-20 showed much greater performance than its precursor, the F-5, and even better than expected.
At first, three aircraft were built; the first fitted with a standard F-5 style canopy and nose radome, while the second and third examples each had a larger blown canopy and larger nose radome for the GE G-200 Radar unit. The flight of a prototype was in August 1982. After two aircraft were lost, Northrop started building a fourth prototype. But after the US Air Force selected the F-16 Fighting Falcon, development was cancelled.
Other countries including Germany and Switzerland were interested in the aircraft, primarily due to an export ban on production standard F-16As which was lifted by the Regan administration in the early 1980s. South Korea and India tried to buy the rights and designations of the aircraft. However, the United States Congress prevented a technology transfer because that would lower the export chances of the F-16 Fighting Falcon. Shortly after, Northrop gave up on the F-20 Tigershark program.