Nicknamed the "T-Bird," the Lockheed T-33 "Shooting Star" was the world's first operational jet fighter trainer, and its development was critical in training military pilots for the higher performance and unique handling characteristics of newly developed jet aircraft that entered service after World War II. Developed directly from Lockheed's successful P-80 fighter design, the first jet fighter the United States put into operational use, the T-33 was created when designer Kelly Johnson added 41 inches to the fuselage and lengthened the canopy to accommodate a second seat and cockpit for training. First flown in 1948, it became the primary jet trainer used by both the USAF and the U.S. Navy through the 1950s and early 1960s, while the Navy's slightly modified carrier-training version was called the T2V/T-33B "SeaStar." Although newer trainers gradually replaced it, many T-33s remained in U.S. military inventory into the 1980s. While the P-80/F-80 fighter on which it was modeled quickly became obsolete, the T-33 served for nearly four decades and became one of the most important and widespread military jet trainers in history. Only 1,715 P-80/F-80 fighters were built, but more than 6,500 T-33s were produced and used not only by the U.S. but by militaries in more than 30 other nations, with several still in training use by the Bolivian Air Force as of 2015. By lengthening the fuselage and extending the bubble canopy, Lockheed turned the P-80/F-80 into the world's first production jet training aircraft, and the T-33 unexpectedly proved slightly faster than the fighter on which it was based, probably because of improved aerodynamics created by its extended nose and canopy. The Allison J-33 turbo engine that powered both aircraft descended directly from the original turbojet engine designed by Sir Frank Whittle, and in the late 1940s the Soviet Union obtained a J-33 engine and reverse-engineered it to power the MiG-15, its first production jet fighter. This specific aircraft is a Canadian-built unit: of 6,557 total T-33s built, 656 were produced for the Canadian Air Force by Canadair under license from Lockheed, and though identical to American-built aircraft, they were named the CT-133 "Silver Star."