The SB-2 was a typical twin-engined monoplane when compared to other World War II era twin-engined bombers. Early SB-2s used two M-100 engines (which were licence built Hispano-Suiza engines), while later models used 2 improved M-103 engines. The former delivered about 830 hp, and the latter delivered 950 hp. These engines propelled the aircraft to a speed of 255 mph (410 kph) in the earlier aircraft and 280 mph (451 kph) in later aircraft. The aircraft was armed with four 7.62 (0.3 in) ShKAS machine guns. Two machine guns were in the nose position, one was in a dorsal position and one was in the ventral position. The Tupolev plane's payload was limited to 2,200 lb (998 kg). The typical crew for a bombing mission in the SB-2 was composed of a pilot, a nose gunner, and a dorsal gunner. The SB-2 was an advanced aircraft for the time, but it lacked refinement. This came to the disappointment of pilots and ground crew, but to the satisfaction of Stalin who said, "there are no trivialities in aviation".
- ANT-40- Light Bomber Prototype.
- SB-2- Second prototype, after second prototype this became the product designation all future Light Bomber Types.
- SB-2M100-first production SB-2 equipped with M-100 engines. 
- SB-2M100A-Production SB-2 with M-100A engines delivering (860 hp) each.
- SB-2bis-Improved SB-2 with three bladed, variable pitch propellers as well as improved fuel capacity and range.
- PS-40- Transport Version.
- PS-41- Transport Version.
- B.71- SB-2 produced under license by Czechoslovakia. Note, the Arkhangelsky Ar-2 (also known as the SB-RK) was a SB-2bis converted into the Dive Bombing role but will have its own separate article.
The SB-2 was first introduced into service in February 1936. In October of that same year, the SB-2 was selected to be exported Spain to assist the embattled Republican forces fight off Nationalist rebels. The SB-2 was the first Soviet warplane sent to Republicans, and the bombers were to be manned by Soviet crews. For the majority of the Spanish Civil War, the SB-2 was untouchable to the Italian Fiat CR.32 and German Heinkel He 51 fighters being used by Franco's Nationalist Forces. The SB-2 was able to outrun most of these biplanes with relative ease. The only way these aircraft could intercept the Tupolev machine was dives from high-altitude. The SB-2 success in Spain would continue until the SB-2 faced stern fighter opposition in 1938. Much of the difficulty the SB-2 had when dealing with fighters later in the war is because of the new Messerschmitt Bf 109B. When the Spanish Civil war ended, a total of 210 SB-2s were delivered to Spain. Total claims of SB-2s shot down over Spain was 14 by the Nationalists, an unknown amount (but close to the Nationalists number) by Germans, and 48 by Italians. 19 SB-2s were captured by the Nationalists at the end of the war. These were used to create a bomber squadron. The SB-2 would suffer from a lack of spare parts. By April 1943, 3 SBs were airworthy in Spain. These would be replaced by Junkers Ju 88s in December of that year, and the remaining aircraft were used in a limited number of training flights before being scrapped in 1948.
On August 21st, 1937, the Soviet Union signed the Sino-Soviet Nonaggression pact. As part of that agreement, the Soviets supplied large amounts of military equipment, and the pact also called for the deployment of Soviet aircraft units crewed by Russian volunteers. The SB-2 was among the Soviet aircraft provided to the Chinese, with the first batch of 62 SB arriving in September-October, 1937.The SB-2 served with other Russian bombers suchs as the Tupolev TB-3 and the Ilyushin DB-3. The first combat action by SB-2s occured on December of the same year, with attacks being launched on Japanese Ships on the Yangtze River. An additional 60 SBs were delivered to China in early 1938. These additional planes were used in large numbers during the Battle of Wuhan to attack Japanese troops.. Heavy losses forced the SB-2 to be temporarily withdrawn from combat. Soviet units were re-equipped with the DB-3, and the SB-2 was transferred to Chinese units. Before signing the Soviet-Japanese Neutrality Pact in 1941, the Soviets provided another 100 SB-2s.
Czechoslovakia and the Soviet Union signed a agreement in 1937, which gave Czechoslovakia the license to produce the Tupolev SB as the Avia B.71.
- Ludeke, Alexander. Weapons of World War II. Bath, United Kingdom: Ludeke, 2012.
- Bishop, Chris. The Encyclopedia of Weapons of World War II. London: Amber Books Ltd, 2018.