In 1927, the Japanese company Mitsubishi commissioned the British aircraft manufacturer Blackburn Aircraft to design an aircraft, which would be built under licence by Mitsubishi if successful, to enter a competition held by the Imperial Japanese Navy for a carrier-based reconnaissance and torpedo bomber to replace its B1M. Blackburn developed a design, the Blackburn T.7B, which was an enlarged development of their Ripon, which was under development for Britain's Fleet Air Arm.[1] The T.7B was a three-seat biplane of steel tube construction and with high aspect ratio wings fitted with Handley Pageslats, powered by a 466 kW (625 hp) Hispano-Suiza 12Lbr engine.
The design was declared the winner of the competition, with a prototype (referred to as the 3MT4) being ordered from Blackburn. This first flew on 28 December 1929 at Blackburn's factory at Brough, Yorkshire,[1] and was shipped to Japan in February 1930.[2]
Three development prototypes were built by Mitsubishi in Japan before the aircraft was adopted as the Navy Type 89-1 Model 1 Carrier Attack PlaneorMitsubishi B2M1.[3]
The B2M1 entered service with the Imperial Japanese Navy in March 1932,[3] serving aboard the carriers Akagi, Kaga and Hōshō. Modifications to improve maintainability resulted in the B2M2orNavy Type 89-2 Carrier Attack Plane, which otherwise showed little improvement in performance over the B2M1. Production of both versions totalled 204 aircraft.[3]
B2Ms were extensively used for high- and low-level bombing attacks against China at the start of the Second Sino-Japanese War in 1937.[3][4]
1 X as second letter is for experimental aircraft or imported technology demonstrators not intended for service,
2 Hyphenated trailing letter (-J, -K, -L, -N or -S) denotes design modified for secondary role, 3 Possibly incorrect designation, but used in many sources
Japan
