- Yes
- No
TL;DR:
Tactical bomber, Czechoslovak SB 2M-100A with different (worse) defensive armament.
Overview:
In 1935 Czechoslovakia and the Soviet Union signed a mutual assistance pact. Included with the treaty was military cooperation, one of which was technology transfer. In 1936 the Soviets acquired licenses for production of Czechoslovak artillery, and in turn the Czechoslovaks acquired the new Tupolev SB bomber, which was the fastest bomber in the world at the time and had proved effective during the Spanish Civil War. The Soviet Union delivered 61 SB bombers to Czechoslovakia and provided a license for local production.
The SB was designated the B-71, and the first one arrived from the Soviet Union in December 1937 for evaluation, with mass delivery taking place in April 1938. The first B-71 was modified after testing with Avia Hispano-Suiza 12Ybrs engines (technically the same engine used in the SB), vz.30 machine guns, and Czechoslovak bombing sights, radios, and other minor equipment. The main deliveries would include these modifications before transfer (and some modifications would also be adopted by the Soviets in later SB variants). In service the Czechoslovaks found some issues with the aircraft, including malfunctioning landing gear and unreliable brakes, but compared to the standard Soviet SB 2M-100A, the Czechoslovak engines had more than double the operating hours of the Soviet M-100A. The B-71s equipped four aviation regiments: two bomber regiments and two recon regiments.
Local production of the B-71 was to be done by Avia with secondary production by Aero and Letov, with a planned 160 aircraft in total. During production Avia also worked on improving the design, a modified engine cowling similar to later SB models and improved radiators. However, that was interrupted by the Munich Crisis, and soon enough in March 1939 Germany would completely occupy Czechoslovakia, seizing the majority of the Czechoslovak military with the rest falling to Hungary and newly independent Slovakia. Very few or even none of the locally produced B-71s would be completed before the occupation, but that did not stop production with Avia ending up delivering most of the B-71s to the Luftwaffe, with a total of 111 being built. The Germans converted most of the B-71s to target towing aircraft, designated the B-71A and B-71B. During the German invasion of the Soviet Union some B-71s would also be used as Ersatz SBs for reconnaissance and dropping saboteurs into Soviet territory. Additionally 24 were sold by Germany to Bulgaria and a B-71 was acquired by Slovakia. None survive, save for a single rudder.
Specifications:
Weight:
Empty: ~4138kg
Take-off: ~5748kgDimensions:
Length: 12.273m
Wing Span: 20.3m
Wing Area: 56.7m²
Height: 3.6mEngine:
2x Avia-HS 12Ybrs inline V-12 engines
760 hp
860 hp takeoff
Fuel: 1130kg
Liquid cooledPerformance:
Max Speed:
372km/h at sea level
424km/h at 4000m
Ceiling: 9560m
Range: 2150km
Rate of Climb: 525m/minuteCrew: 3
Armament:
3x1 7.92mm vz.30 in defensive turretsOrdnance:
500 - 600kg of bombs (unknown what bombs they used)
Images:
The vz.30 replacing the twin ShKAS shown in the first imported B-71
A production B-71 nose, note the lack of the shell ejection chute compared to the previous image
The navigator/bombardier’s station
The same (early) B-71 crash landed, due to aforementioned landing gear issues
Apparently a large number of B-71s had an incorrect roundel orientation (Soviet pre-painting?)
A surviving rudder of a B-71
Drawings:
A camo scheme diagram
Sources:
Stapfer, H. (2004). Tupolev SB in Action (pp. 12. 15-22). Squadron/Signal Publications.
Maslov, M. (2004). Tupolev SB Soviet High Speed Bomber (pp. 126-129, 189). Icarus Aviation.
Gunston, B. (2006). Tupolev Aircraft Since 1922 (p. 93). Putnam.
Nemecek, V. (1986). The History of Soviet Aircraft from 1918 (p. 147). Collins Willow.
https://www.airwar.ru/enc/bww2/b71.html