Su-27 Flanker

The Su-27 came out of the Soviet Union's 1970s "future frontline fighter" requirement, aimed squarely at the American F-15. The first T-10 prototype flew in 1977, but testing exposed serious aerodynamic and structural problems, and Sukhoi did something rare for the era: started over. The T-10S that flew in 1981 was very nearly a new aircraft — and became the Su-27.

Its downstream influence may exceed that of any other fourth-generation fighter. The J-11, Su-30, Su-33, Su-34, and Su-35 all descend from this airframe, and the Su-57's central lifting body continues the same line of thinking. Derivatives remain frontline equipment in China, India, and Vietnam today.

The integrated aerodynamic layout is the Su-27's defining idea: wing and fuselage have no clear boundary but blend into one continuous lifting surface, with two widely spaced engines and a fuselage section between them that itself generates lift. That thinking passed directly to the Su-57.

Vortex lift from large leading-edge extensions keeps it controllable at high angles of attack; combined with relaxed static stability and fly-by-wire, it produced post-stall manoeuvres such as Pugachev's Cobra. Those have limited combat value, but they do reflect genuine control margin in the low-speed, high-alpha regime.

Internal fuel reaches 9.4 tonnes, giving a combat radius far beyond the contemporary F-16 at the cost of much greater empty weight and size. The mechanically scanned N001 radar has a large aperture and long detection range, but its multi-target capability lagged Western sets of the period — a general weakness of Soviet electronics, and the main thing later Flanker variants set out to fix.