Sukhoi Su-17

The Sukhoi Su-17 (NATO reporting name: Fitter) is a Soviet variable-sweep wing fighter-bomber developed from the Sukhoi Su-7. It enjoyed a long career in Soviet, later Russian, service and was widely exported to Eastern Bloc, Arab air forces, Angola and Peru as the Su-20 and Su-22. It is the first variable-sweep wing of Russian/Soviet origin. The Su-17 set a number of world records.

Development

Seeking to improve low-speed and take-off/landing performance of the Su-7B fighter-bomber, in 1963 the Sukhoi OKB with input from TsAGI created a variable-sweep wing technology demonstrator. The Su-7IG (internal designation S-22I, NATO designation "Fitter-B"), converted from a production Su-7BM, had fixed inner portions of the wing with movable outer segments which could be swept to 28°, 45°, or 62°. A fixed inner wing simplified construction, allowing the manufacturer to retain the Su-7 landing gear and avoiding the need for complex pivoting underwing hardpoints, and it minimized the shift in the center of pressure relative to the center of mass with change in wing sweep. The new wing also had extensive leading-edge slats and trailing-edge flaps. Su-7IG first flew on 2 August 1966 with V. S. Ilyushin at the controls, becoming the first Soviet variable geometry aircraft. Testing revealed that take-off and landing speeds had decreased by 50–60 km/h (31–37 mph) compared to the conventional Su-7.