The first flight of the prototype took place in 1977. In 1982, aircraft began to enter aviation units, their operation began in 1985, and was put into service on August 23, 1990. Su-27 is one of the main aircraft of the Russian Air Force, its modifications are in service in the CIS countries, India, China and others. On the basis of the Su-27, a large number of modifications have been developed: the combat training Su-27UB, the carrier-based fighter Su-33 and its combat training modification Su-33UB, multi-role fighters: Su-30, Su-27M, Su-35, front-line bomber Su -34 and others. Aircraft of the Su-27/30 series for 2019 occupied the third place in terms of number among the most common combat aircraft in the world, being the most common Russian-made combat aircraft.