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 and was under development for Britain's
Fleet Air Arm. The T.7B was a three-seat
biplane of steel tube construction and with high
aspect ratio wings fitted with
Handley Page slats, 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
3MR4) being ordered from Blackburn. This first flew on 28 December 1929 at Blackburn's factory at
Brough,
Yorkshire Three development prototypes were built by Mitsubishi in Japan before the aircraft was adopted as the
Navy Type 89-1 Model 1 Carrier Attack Plane or
Mitsubishi B2M1. ==Operational history==