The Nakajima B5N (Allied codename: “Kate”) was a single-engine, carrier-based torpedo bomber flown by the Japanese Navy in the first years of World War II. In 1941, it was considered the best torpedo plane in the world.
In 1935, the Japanese Navy announced a competition for a fast, single-engine torpedo bomber. Aircraft companies Mitsubishi and Nakajima both submitted designs, but Nakajima won the contract, and the B5N first flew in 1937. The new bomber was very advanced for its time, with retractable landing gear, a variable pitch propeller, integral wing tanks, and folding wings to save space. The plane carried a three-man crew (pilot, navigator/bombardier, radio man/rear gunner). A Nakajima, air-cooled, 800 hp engine gave it a top speed of 217 mph. Over 1100 B5Ns were produced.
The Kate first saw action in the Second Sino-Japanese War as a level bomber. The plane performed well, but deficiencies cropped up in combat operations, and the Kate underwent a refinement in 1939. The new version, the B5N2, had a more powerful engine and better performance. By late 1941, the B5N2 had largely replaced its predecessor, although some older Kates still served in front-line units and others were used for training.
The Kate established its reputation immediately. At Pearl Harbor, a B5N2 dropped the armor-piercing bomb that set off the battleship Arizona’s ammo magazine, sinking her with almost all hands. Kates played pivotal roles in the battles of Wake Island, Coral Sea, Midway, and Santa Cruz, although they suffered heavy losses in the latter.
By 1943, the Kate’s replacement, the B6N “Jill”, had started to come off the Nakajima assembly lines for deployment to Navy units. However, some Kates were still in front-line service onboard carriers as late as the Battle of the Philippine Sea, where they served as scout planes. Some were also used in anti-submarine and maritime reconnaissance duties
- The Illustrated Encyclopedia of Combat Aircraft of World War II, by Bill Gunston, Salamander Military Press, 1990
- Complete book of World War II Combat Aircraft, by Enzo Angelucci and Paolo Matricardi, VMB Publishers, 2006
- Clash of the Carriers: the True Story of the Marianas Turkey Shoot of World War II, by Barrett Tillman, New American Library, 2005
- Nakajima B5N Kate