Early in World War II, the Mitsubishi Zero—one of the all-time great dogfighters—proved that lightweight fighters were viable. Soon, heavier and more expensive aircraft, like the Grumman Hellcat, would topple the Zero—diminishing the stature of lightweight fighters in the eyes of military planners.

By the 1960's, outmoded dogfighters were being replaced by big, heavy fighters with radar guided air-to-air missiles. But faced with the formidable new MiG 21 in Vietnam, the U.S. Air Force was forced to give lightweight fighters a second look.