The Northrop T-38 Talon is an American supersonic jet trainer. It was the world's first supersonic trainer and to date, is also the most produced. It remains in service as of 2011 in air forces throughout the world.
The United States Air Force (USAF) is the largest user. In addition to USAF pilots, the T-38 is used in the United States by NASA astronauts, with the aircraft bailed to NASA from USAF. The U.S. Naval Test Pilot School is the principal U.S. Navy operator (other T-38s were previously used as USN aggressor aircraft until replaced by the similar F-5 Tiger II), as well as some NATO pilots participating in joint training programs, also fly the T-38. A few are also under civilian ownership.