At a time when the triumphs of the B5N were still almost three years in the future, the Japanese navy issued a specification for a replacement, recognizing that only limited overall design improvement of the B5N could be achieved in the B5N2. Accordingly design went ahead in 1939 of the Nakajima B6N and, despite the navy's preference for the Mitsubishsi Kasei radial, a Nakajima Mamoru was selected for the prototype which flew early in 1941. Superficially the B6N Tenzan (heavenly mountain) resembled the earlier aircraft, but the much increased power and torque of the big engine and four-blade propeller was found to impose considerable directional stability problems, demanding that the vertical tail surfaces be offset to one side. Flight trials dragged on, and were further delayed by troubles during carrier acceptance tests; then Nakajima was ordered to stop production of the Mamoru engine, so modifications had to be introduced to suit installation of the Kasei. In due course B6N1 aircraft (of which only 133 were built) were embarked in the carriers Shokaku, Taiho, Hiyo, Junyo and Zuikaku, and took part in the great Battle of the Philippine Sea of June 1943, many being lost when the three first-named carriers were sunk. In that month production started of the slightly improved B6N2 (of which 1,133 were produced before the end of the war), but the heavy losses among Japanese carriers resulted in the 'Jill' being largely deployed ashore, particularly after the Battle of Leyte Gulf. Thereafter many BSNs were consigned to the kamikaze role.

3-View

A three-view drawing (752 x 963)