Northrop YF-5A Freedom Fighter The F-5 was a supersonic fighter that combined low cost, ease of maintenance and great versatility. The U.S. Air Force procured more than 2,000 of these aircraft for use by allied nations. The F-5, which closely resembled the USAF Northrop T-38 trainer, was suitable for various types of ground-support and aerial intercept missions, including those conducted from unpaved fields in combat areas. The F-5 first flew in July 1959, and deliveries to the Tactical Air Comm