Appendices - Hirohito's War
E. Typhoons and Divine Winds: Kamikaze
Developments in Kamikaze Technology and the US Response: As the kamikaze campaign developed so did the weaponry that they used. At first, the airplanes used were Mitsubishi Zero fighters or Aichi D3A dive-bombers loaded with heavy bombs. Later, sophistication was added by the special packing of the Japanese kamikaze aircraft with explosives. In addition Yokosuka D4Y ‘Judy’ bombers and Kawasaki Ki-48s, with their bigger payloads, were converted for use as suicide aircraft. Seven of the latter aircraft were launched from Palembang in Sumatra and aimed at the British fleet on 29 January 1945. Twin-engine Mitsubishi Ki-67 Hiryu ‘Peggy’ bombers based in Formosa were also used.
Special kamikaze aircraft were also developed. Mitsuo Ohta, an ensign, had suggested that a mother plane, a twin-engine ‘Betty’ bomber should launch kamikaze pilots in glider bombs. His idea was taken up by the First Naval Air Technical Bureau in Yokosuka, which developed rockets that could be launched from the underside of Japanese bombers with pilots strapped to them like jockeys, who were provided with rudimentary steering controls. These Yokosuka MXY7 Ohka (cherry-blossom) rocket planes, carrying a ton of tri-nitro-anisol explosive, looked like torpedoes with wings. They were nicknamed Baka bombs (idiot bombs) by American sailors.
They were first used on 11 March 1945. Admiral Mitscher’s interceptor pilots noticed that the ‘Betty’ bombers were slower than usual and looked odd. When intelligence photos revealed that there was a winged bomb under each wing, the American Admiral realized that they had a new kamikaze weapon to deal with. Faster than conventional aircraft, the Ohka could travel at 500 knots and was extremely difficult to shoot down. On the 9 April, at the opening of the Battle of Okinawa, a baka hit the destroyer USS Mannert L. Abele, lifted it out of the water and broke it in two. The US destroyer sank in minutes. In addition a cheaply built wooden framed plane built around a Nakajima engine, the Ki-115 Tsurugi (sabre), was specifically designed for kamikaze pilots. Its simple, non-retractable landing gear, surplus to requirements after takeoff, was jettisoned and could be reused. The Japanese Army began to stockpile Ki-115 Tsurugis on Kyushu Island, the third largest of the home islands, when it became evident that this would be the likely next invasion point for US forces.