The Northrop F-5A/B Freedom Fighter and the F-5E/F Tiger II are part of a supersonic light fighter family, initially designed in the late 1950s by Northrop Corporation. Being smaller and simpler than contemporaries such as the McDonnell Douglas F-4 Phantom II, the F-5 cost less to both procure and operate, making it a popular export aircraft. The F-5 started life as a privately funded light fighter program by Northrop in the 1950s.