The Northrop T-38 Talon is a twin-engine supersonic jet trainer. It was the world's first supersonic trainer and is also the most produced. The T-38 remains in service as of 2011 in air forces throughout the world.
The United States Air Force (USAF) is the largest operator of the T-38. In addition to training USAF pilots, the T-38 is used by NASA. The US Naval Test Pilot School is the principal US Navy operator (other T-38s were previously used as USN aggressor aircraft until replaced by the similar Northrop F-5 Tiger II), as well as some NATO pilots participating in joint training programs, also fly the T-38.