The Mitsubishi B5M 'Kate' was a torpedo bomber developed alongside the more successful Nakajima B5N, but that also entered production and saw some limited front line service.
Both aircraft were developed in response to a 10-Shi specification for a carrier attack aircraft. While Nakajima introduced a number of innovations on their aircraft, Mitsubishi went for a more conventional design. The B5M had a fixed undercarriage in streamlined fairings, manually folded wings from the start and simple flaps. In contrast the original B5N use Fowler flaps, hydraulically folded wings and a retractable undercarriage, although production machines only kept the last of these.
The B5M was powered by a 1,000hp Mitsubishi Kinsei engine, and out-performed the B5N1. It had a top speed of 235mph, compared to the 229mph of the Nakajima aircraft, and better take-off performance. Despite these advantages, the Mitsubishi aircraft was judged to be inferior to the Nakajima design, although both were ordered into the production. A total of 125 B5Ms were built, all during 1937, and entered service as the Navy Type 97 Model 2 Carrier Attack Bomber. Nakajima won the mass production contracts, partly because their aircraft had more potential for development and partly because Mitsubishi was already busy with the A5M Navy Type 96 Carrier Fighter and the upcoming Zero fighter.
The B5M was used for anti-submarine patrols from Southern China and Hainan in the early part of the Pacific War, but it was soon moved to secondary duties. It was so similar to the Nakajima aircraft that both were given the Allied code name 'Kate'.
Engine: Mitsubishi Kinsei 43
Wing span: 50ft 2 3/8in
Length: 33ft 10 15/32in
Loaded Weight: 8,818lb
Max Speed: 237mph at 7,220ft
Range: 1,367 miles
Armament: One flexibly mounted 7.7mm machine gun
Bomb-load: 1,764lb of bombs or one torpedo