The B2M combines imported components with Japanese production

Japan asked Blackburn for a larger, customized development of the Ripon torpedo bomber, with different wings and a different engine. The selected Hispano engine performed well when maintained, although engines of this family had a reputation for requiring considerable maintenance. The design also used Handley Page slats, combining components from different suppliers. Blackburn built the T7B prototype, and Mitsubishi built three more prototypes to verify its manufacturing work before production. Later changes reduced the wingspan and enlarged the tail. The B2M proved reliable and easy to fly, making it useful for torpedo training and bombing over China. Its quoted range supported an estimated strike radius of roughly 450 nautical miles if the target's position was known and the aircraft could fly directly out and back.