The aircraft carried several designations across its life. ANT-40 was the Tupolev design-bureau prototype designation (ANT for Andrei Nikolaevich Tupolev). In service it became the إس بي — from the Russian Skorostnoi Bombardirovshchik, “fast bomber” — and is widely referred to as the SB-2 in Western sources, with sub-variants such as the SB-2M-100, SB-2M-103 and the improved SB-bis. In Republican Spain it earned the nickname “Katiuska” (after a popular operetta of the day). Civil and transport conversions were designated PS-40 و PS-41. Designations and exact figures vary between sources, so treat sub-type numbers as approximate.

The SB was influential out of proportion to how it is remembered today. Its combination of monoplane layout, retractable undercarriage, all-metal construction and high speed pointed directly at the shape of the medium bombers that would fight the Second World War. It gave the Soviet Union a modern strike aircraft years before many rivals, and its performance in Spain forced fighter designers everywhere to take the “fast bomber” threat seriously. That the SB was then overtaken so completely by 1941 does not diminish how genuinely advanced it had been in 1934 — it simply shows how fast the pace of aviation was in that decade.

The SB’s engines trace directly to the Hispano-Suiza 12Y, licence-produced in the USSR by the Klimov works. Early aircraft used the M-100 (about 750–860 hp); later production switched to the more powerful M-103 (commonly cited around 960 hp), giving the definitive SB-2M-103 / SB-bis its best performance. The water-cooled V12s were relatively light and streamlined, which suited the fast-bomber concept, but their radiators and coolant lines were vulnerable to battle damage — a weakness that told heavily once fighters could catch the SB. Power figures vary by source and variant; treat them as approximate.

Because the design assumed speed would keep it safe, the SB carried only a handful of rifle-calibre machine guns, no meaningful armour for the crew, and unprotected fuel tanks. When it could no longer outrun its attackers — against the Bf 109 in Spain, Finnish fighters in the Winter War, and the Luftwaffe in 1941 — those economies became lethal. Unescorted daylight formations were especially exposed, and losses in the opening phase of Barbarossa were among the heaviest suffered by any bomber type of the early war. The SB is often cited as a textbook example of how quickly an “untouchable” aircraft can become obsolete.

Unlike modern jets, the SB has no reliably recorded unit price or cost-per-flight-hour in accessible Western sources — Soviet 1930s industrial accounting was opaque, and figures that survive are inconsistent. What is clear is that the SB was deliberately designed for mass, low-cost production: it was simple enough to be turned out in the thousands at Factories No. 22 (Moscow) and No. 125 (Irkutsk), and cheap enough to be exported and licence-built abroad. For that reason we list its cost rows as “not reliably recorded (1930s)” rather than publish a spurious number.

Major variants included the early SB-2M-100 و SB-2M-100A; the improved SB-2M-103 / SB-bis with more power and refined aerodynamics; the transport conversions PS-40/PS-41; and the dive-bomber development Arkhangelsky Ar-2 (a deeper redesign sometimes treated as a separate type). Abroad, Czechoslovakia licence-built the SB as the Avia B-71, and examples later served with Bulgaria, Slovakia and — as captured aircraft — Finland and Germany. Variant designations and production splits differ between sources; the figures here are approximate.