According to Wikipedia: "The Northrop F-5A/B Freedom Fighter and the F-5E/F Tiger II are part of a family of widely used light supersonic fighter aircraft, designed and built by Northrop. Although less complex and advanced than some contemporary aircraft such as the McDonnell Douglas F-4 Phantom II, it was significantly cheaper to procure and operate, and the type became a popular aircraft on the export market. While not procured in volume by the United States, it was perhaps the most effective air-to-air fighter possessed by the U.S. in the 1960s and early 1970s. The aircraft had a compact size, high maneuverability, favorable flying qualities, low accident rate, and high sortie generation rate. As with the similar Soviet Mikoyan-Gurevich MiG-21, these positive qualities led to many F-5s remaining in service into the 21st century. In terms of pilot opinion of flying qualities, the F-5 ranks highly, comparable to the North American F-86 Sabre and the General Dynamics F-16 Fighting Falcon. "