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.
Engine: Shvetsov M-82FN radial, 1,850hp and 1 x Korolyov-Glushko RD-1KhZ bi-fuel rocket motor, 300kg thrust
Max take-off weight: 4340 kg / 9568 lb
Wingspan: 13.50 m / 44 ft 3 in
Length: 9.60 m / 32 ft 6 in
Wing area: 26.00 sq.m / 279.86 sq ft
Max. speed: 680 km/h / 423 mph
Range: 1240 km / 771 miles
Sukhoi Su-7 (I)