The MiG-15 was a high-subsonic jet fighter developed by the Soviet Mikoyan Design Bureau. When the design of the model began in 1946, it was deeply influenced by the captured Nazi German Ta183 (code name: Raven) jet aircraft, but the overall design was completed by Soviet designers. The Soviet Union began research on gas turbine engines as early as the 1920s, but progress was far behind that of Britain and Germany. In May 1945, after Germany's defeat and surrender, the Soviet Union seized a large amount of research data on jet engines. According to these materials, the most famous Yakolev Design Bureau and Mikoyan Greevich Design Bureau ("MiG Design Bureau") of the Soviet Patriotic War simultaneously launched the development of jet aircraft, using German jet engines and Soviet-made aircraft bodies respectively, developed the Yak-15 and MiG-9 jet fighters. On April 24, 1946, both aircraft made their first test flight and passed the certification.