Tupolev SB

ANT-40 / SB
Finnish captured SB
General information
Type	Fast bomber
Manufacturer	Tupolev
Designer	Alexander Arkhangelsky
Primary users	Soviet Air Forces Czechoslovak Air Force Chinese Nationalist Air Force Luftwaffe
Number built	6,656
History
Manufactured	1936–1941
Introduction date	1936
First flight	7 October 1934
Retired	1950 (Spanish Air Force)
Developed into	Arkhangelsky Ar-2

The Tupolev ANT-40, also known by its service name Tupolev SB (Russian: Скоростной бомбардировщик – Skorostnoi Bombardirovschik – high speed bomber) and development co-name TsAGI-40, was a high speed twin-engined three-seat monoplane bomber, first flown in 1934. The Tupolev design was advanced but lacked refinement, much to the dismay of crews, maintenance personnel, and Stalin, who pointed out that "there are no trivialities in aviation".

Numerically the most important bomber in the world in the late 1930s, the SB was the first modern stressed skin aircraft produced in quantity in the Soviet Union and probably the most formidable bomber of the mid-1930s. It was produced in the Soviet Union and was also built under license in Czechoslovakia. Many versions saw extensive action in Spain, the Republic of China, Mongolia, Finland and at the beginning of World War II against Germany in 1941. It was also used in various duties in civil variants, as trainers and in many secondary roles. Successful in the Spanish Civil War because it outpaced most fighters present (composed mostly of biplanes), the aircraft was obsolete by 1941 as faster fighters (such as the Bf-109) had by then been introduced.^{[clarification needed]} By June 1941, 94 percent of bombers in the Red Army air force (VVS RKKA) were SBs.