Most Northrop T-38s built were of the T-38A variant, but the USAF also had a small number of aircraft that had been converted for weapons training. These aircraft (designated AT-38B) had been fitted with a gunsight and could carry a gunpod, rockets, or bombs on a centerline pylon. In 2003, 562 T-38s were still operational with the USAF and are currently undergoing structural and avionics programs (T-38C) to extend their service life to 2020. The fighter version of the T-38 was eventually selected for the US Military Assistance Program and produced as the F-5 Freedom Fighter. Many of these have since reverted to a weapons training role as various air forces have introduced newer types into service.(Wikipedia)