Sukhoi Su-27UB
The two-seat combat trainer that kept the full Flanker weapon system · First flight 1985 · In service 1986
The Su-27UB (uchebno-boyevoy, "combat trainer") adds a second cockpit in tandem behind the first under a long, raised canopy. Unlike many trainer versions, it retained the radar, infrared search-and-track system, cannon and missile armament of the single-seater, so it could be used as a fighter as well as for conversion training — which is why NATO gave it a separate reporting name, Flanker-C.
The first prototype, T-10U-1, flew in 1985 with Nikolai Sadovnikov at the controls. Series production was moved to the Irkutsk aircraft plant in 1986 and deliveries of production trainers started late that year. The export version, the Su-27UBK, went to China and Vietnam, and Irkutsk's two-seat Flanker line later grew into the Su-30 family.
Ukraine flew its Su-27UBs at Western airshows for years, and Belarus upgraded some to Su-27UBM1 standard. Two demilitarised former Ukrainian Su-27UBs were bought by a private company in the United States and acquired by the US Air Force in 2011; one is now displayed at the National Museum of the United States Air Force.
