The B5M and B5N had closely comparable performance, yet the B5N consistently won out and became the major production type. The B5M functioned as an industrial hedge: a second company and second line could have increased Japanese torpedo-bomber availability. Only 125 B5Ms were built against more than 1,100 B5Ns, and many B5Ms finished as trainers, target tugs, or kamikaze aircraft. Its failure to establish the second line reveals the narrowness of Japan's production capacity even where the design ambition was clear.
Notable Point · 2:35:41-2:40:32
The B5M and Japan's search for a second production line
The Mitsubishi B5M was meant to supplement the Nakajima B5N, showing Japan's attempt to expand carrier-aircraft output through parallel production.