The Yokosuka B4Y1 three-seat carrier attack bomber was designed to meet a requirement of 1934, the evaluation of five prototypes with different power-plant being followed by 205 production aircraft built during 1937-38. Designated officially as the Navy Type 96 Carrier Attacker, these aircraft were used as advanced trainers after Pearl Harbor but, as the Allies believed they were still in first-line service, the type was allocated the code-name 'Jean'.
