United States Air Force
The Northrop T-38 Talon is a two-seat, twinjet 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 2018 in several air forces.
The United States Air Force (USAF) operates the most T-38s.
In addition to training USAF pilots, the T-38 is used by NASA.
The U.S. 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).
Pilots of other NATO nations fly the T-38 in joint training programs with USAF pilots.
As of 2018, the T-38 has been in service for over 50 years with its original operator, the United States Air Force.