https://www.planetminecraft.com/project/su-27-s-1-5-1/

Development of the Su-27 began at the Sukhoi Design Bureau in early 1971. In 1977, the first prototype was built for testing. Due to a change in the concept of future aircraft, the team of aircraft manufacturers had to design an essentially new aircraft, only partially using the developments of the original project. The new prototype was ready by the end of 1980, and its flight tests began in the spring of 1981. The first Su-27s began to enter service with the armed forces in 1984, even though tests of a number of systems had not yet been completed. Today, Su-27 fighters of various modifications are in service with Russia, China, Ukraine, Kazakhstan, Uzbekistan and other countries.