In 1948, because of the heavy losses of early jet fighters and their pilots, Lockheed Aircraft Corporation began using its own funds to modify the F-80 Shooting Star into a jet trainer by lengthening the fuselage for a second seat and fully equipped cockpit, adding a seven-foot clamshell canopy, reducing the fuselage fuel tank, and cutting armament to two .50 caliber machine guns. The Air Force, impressed by the aircraft's characteristics, began awarding contracts in April 1948, and in 1949 designated the trainer the T-33A, while the Navy and Marine services called it the T-33B or T-2V. Powered by a 5,400 lb. static thrust Allison J-33A-35 turbojet, with the addition of Fletcher wing tip tanks for extra fuel as its only major design change, the aircraft became central to pilot training, in which students received 500 hours of ground instruction, 100 hours of basic flight training, and then 75 hours in the T-33A before moving on to fighter aircraft. Lockheed built 5,691 T-33s before production ended in August 1959, and the T-33A served as the Air Force's principal advanced trainer for three decades; an estimated 90 percent of the free world's jet pilots trained in it during the 1950s and 1960s. Known as the T-Bird, it was later replaced by the Cessna T-37 but remained widely used by the Air Force until the last active T-33 squadron retired in 1988, ending nearly 40 years of service. This T-33A was built by Lockheed and delivered to the Air Force on 30 July 1952, then assigned to Pinecastle Air Force Base, Florida, with the 3540th and 4240th Flying Training Wings, stationed at Tyndall AFB, Florida, from 1954 to 1957 with the 3625th FTW, moved in 1958 to Lackland AFB, Texas, with the 3700th Military Instruction Wing, and finished its career in 1961 at Kelly AFB, Texas, before being dropped from inventory as surplus in July 1962.