The Lockheed-built T-33 originated as the trainer version of the U.S.'s first operational jet fighter, the F-80 "Shooting Star." Sabreliner's contract required the disassembly, remanufacture and modification of 24 surplus USAF T-33 jet aircraft to an attack/trainer configuration. Sabreliner overhauled the aircraft, updated them to incorporate all current Technical Orders, and performed major modifications including installations of improved avionics, .50 caliber guns, and optical sights. The program was accomplished on schedule and within budget.