General Information
Type Su-8, 'B', DDBSh
Function Long-range strike aircraft
Year 1943
Crew 2
Powerplant
Type 2*M-71F
Power at takeoff 2*2200hp
Power at 3600m 2*1900hp
Size
Length 13.5m
Height m
Wingspan 20.5m
Wing area 60.0m2
Tailplane area 10.2m2
Tailfins area 6.6m2
Weights and loads
Empty 9180kg 9218kg
Normal Takeoff 12425kg 12736kg
Overload 13380kg
Wing load (normal) 207 212
Wing load (overload) 223
Power load (normal) 3.27 3.35
Power load (overload) 3.52
Speed
at 0m 485km/h
at 4600m 550km/h
Landing 140km/h
Roll
Landing 350m
Takeoff 350m
Operational Range
Full load 600km
Without bombs 1450km
Ceiling
Ceiling 9000m
Climb
3000m 7.3min
5000m 9min
Payload
Fuel+Oil 2370kg
Armament
Guns (offensive) 4*37mm NS-37 4*45mm NS-45
8*7.62mm ShKAS
Guns (defensive) 1*12.3mm UBT
1*7.62mm ShKAS
Bombs 4*150kg

Su-8 ('B', DDBSh) long range attacker by P.O.Sukhoj

Su-8 attacker
Su-8 photo, seen at almost any publication about Soviet Air Force
Courtesy of Thomas Heinz

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.

P.O.Sukhoj was ordered to build two prototypes. But under desperate conditions of industry evacuation little could be done, and aircraft 'B' (factory designation) was built only in 1943.

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.

Defensive armament included dorsal 12.3mm UBT mounted in the rear cockpit (some source put it into small power-driven turret) and ventral 7.62mm ShKAS machinegun.

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.

Trials were abruptly cancelled during the second half of 1944. Version with AM-42 engines remained on drawing boards.

PredecessorsModifications
None None
ReferencesLinks
  • "History of aircraft construction in the USSR", Vol.2 p.259-361;
  • "Russian aircraft since 1940", p.334
  • "Russian Civil and Military aircraft 1884~1969" by Heinz J.Nowarra and G.R.Duval, p.147;
  • Su-8 at Virtual Aircraft Museum
  • Su-8, Sukhoi
  • The Ultimate Shturmovik: Sukhoi's Long-Ranging Su-8

  • Created January 25, 1996
    Modified February 21, 2000
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