Sukhoi Su-7 (I)

Chronologically, the Su-7 mixed-power high-altitude interceptor preceded the Su-5, being based broadly on the single-seat Su-6(A) assault aircraft. Intended to fulfil a 1943 requirement, the Su-7 retained the single-spar metal wing of the experimental shturmovik, mated to a new all-metal semi-monocoque fuselage. It was proposed that the fighter be powered by the 2,200hp Shvetsov M-7118-cylinder two-row radial engine with paired TK-3 turbo-superchargers, but non-availability of this power plant led to the decision to install a 14-cylinder two-row Shvetsov M-82FN radial engine rated at 1,850hp and supplemented by a Korolyov-Glushko RD-1KhZ bi-fuel rocket motor developing 300kg thrust with a burn time of four minutes. Flight testing of the Su-7 with the rocket motor commenced in the late summer of 1944. Although the unstable nature of the rocket power plant motivated against adoption of the Su-7, flight testing revealed that it boosted maximum speed by 83km/h at 7,500m and by 195km/h at 13,000m. Armament comprised two wing-mounted 20mm cannon, and the sole rocket-powered Su-7 prototype was being prepared for the first post-World War II air display over Moscow in 1945 when the rocket motor exploded, killing the pilot and destroying the aircraft.

3-View

A three-view drawing (1665 x 1210)