The Su-27S (NATO reporting name – Flanker) is a single-seat highly-maneuverable fighter aircraft built by Sukhoi Design Bureau as the Soviet response to the U.S. F-14 and F-15 and entered service in 1985. The primary role of the Su-27 was to provide defense against American bombers, USN ships and provide Soviet bomber escorts. There have been many improvements over the years resulting in numerous variants of the Su-27. The export variant, the Su-27SK was sold to China and eventually developed into the license-built Shenyang J-11.
Su-27SM Flanker B "Black Sea" Blue 26 is one of the aircraft assigned to the Southern Military District’s 4th Air and Air Defence Forces Command headquartered at Rostov-on-Don. The task of this unit is to protect the Black Sea region which is Russia’s smallest military district. One aircraft based there is Su-27SM Blue 26 RF-92417. The Su-27SM looks almost identical to the previous Su-27P but has more advanced technologies, new engines and is considered to be the main aircraft in the region to defend against intruders.

Info: Su-27SM Flanker B "Black Sea" Blue 26, Russian Air Force, 2016