|Type||Su-8, 'B', DDBSh|
|Function||Long-range strike aircraft|
|Power at takeoff||2*2200hp|
|Power at 3600m||2*1900hp|
|Weights and loads|
|Wing load (normal)||207||212|
|Wing load (overload)||223|
|Power load (normal)||3.27||3.35|
|Power load (overload)||3.52|
|Guns (offensive)||4*37mm NS-37||4*45mm NS-45|
|Guns (defensive)||1*12.3mm UBT|
Shortly after the New Year 1942 first on-ground strategic success of Anti-Hitler coalition was enjoyed by the Soviet Army: German attack on Moscow was put to halt, and following counter-offense pushed group 'Center' backwards 100...250km.
In this situation Kremlin planners were already preparing for future full-scale offensive over vast areas of Western Russia. In this situation, close-range front-line 'Stormoviks' (Il-2 and Su-6) needed a supplement of long-range partner, capable to perform deep penetration attacks on retreating enemy troops and heavily defended supply lines. Specifications were put together in the DDBSh request.
Su-8 (as the built aircraft was designated) emerged as the most powerful, most heavily armed, best protected attacker of the war. The designers set out to build the smallest airframe that could carry requested fuel and armament. Two of the most powerful available engines were fitted M-71F.
Crew of two and large fuel tank were contained in fully structural armored (1600kg up to 15mm thick) shell. Engines and oil coolers were also armored. Extensive bullet-proof glazing provided pilot with very good view for this class of aircraft. Twin fins and rudders provided redundancy in case of combat damage and gave gunner a better field of fire.
But it was an offensive weapons the aircraft was about. The main armament was arranged in a single shallow underbelly battery. First prototype carried four 11-P-37 (later known as NS-37) 37mm cannons, capable to knock out ether Tiger or Panther tanks with 735g shells (900m/sec muzzle velocity, 250shots/min). Those shells could penetrate 40mm armor at angle up to 45°.
Second prototype received even more firepower: NS-45 anti-tank gun was essentially same NS-37, but with larger bore and shorter barrel. 1065g shells were fired at same rate (850m/sec muzzle velocity) and guaranteed penetration of 58mm armor. Both first and second prototype had a clip-feeding for big guns (50 rounds clips were served by the gunner/radio-operator), but fully-automatic feeding was already in test. Salvo of those guns reached 1ton/min, a record for any war time aircraft.
For sighting and soft target attacks, eight ShKAS machineguns were housed in outer wing panels. A total 5900 rounds were provided for machineguns (what about cannons??) And four 150kg bombs could be carried in the in-wing armored bomb bays between the engines and fuselage.
Most (if not all) armored aircraft of the WW-II which emerged overweight and ill-handling. Even the best of those (like the Il-2) were tolerated for their utilitarian virtues, but not loved for their flying qualities. But the Su-8 proved to be an excellent airplane, with first-rate handling at all design weights. This was achieved by careful balancing of different material (from aluminum alloys and armor to wooden elements).
Su-8 entered trials in late 1943. But its time was already past in the eyes of the officialdom. Soviet Union was already winning the war, and nobody was willing to interrupt well-established production of existing war-winning aircraft. Given the outcome, it was a right decision. But there is no doubt that many Soviet soldiers could be saved when Soviet quickly advancing spearheads often meet elephantine heavy tanks hundred kilometers away from the airfields.
|Created January 25, 1996
Modified February 21, 2000