Ohka

It was a small flying bomb[?] that was carried underneath a bomber to within range of its target, where it would be released and the pilot would fire the Ohka's engine and begin his dive towards the target.

The first operational Ohkas (Type 11 and Type 21) were powered by solid fuel rocket motors, which provided great speed but only very limited range. This was problematic, since it meant that the carrier aircraft would have to get too close to the targets, where they were extremely vulnerable to fighter defences.

The Ohka Type 22 was designed to overcome this problem by using a thermojet style jet engine, the Tsu-11[?]. This engine was successfully tested, and Ohkas had been built to accept this engine, but none appear to have been used operationally.

The final stage in Ohka development was the Type 43, which was intended to be powered by an Ne-20[?] turbojet. Two trainer versions were also under development for this version, the K-1 and the K-1 Kai, the former being a glider, and the latter fitted with a single rocket motor.

Some 850 were built, mostly Type 11. Surviving Ohkas include:

• Type 11 - Royal Air Force Museum[?], Cosford[?]
• Type 11 - Fleet Air Arm Museum[?], Yeovilton[?]
• Type 11 - Manchester Air and Space Museum[?], Manchester
• Type 11 - Defence Explosives Ordinance School[?], Kent
• Type 11 - Indian Air Museum[?], New Delhi
• Type 11 - Iruma Air Force Base[?], Saitama
• Type 11 - USMC Air Ground Museum[?], Quantico[?]
• Type 22 - Smithsonian National Air and Space Museum[?], Washington DC (recently restored)
• Type 43 K-1 (rebuilt to represent a Type 11) - USAF Museum[?], Dayton,
• Type 43 K-1 - Navy Memorial Museum[?], Washington DC
• Type 43 K-1 Kai - Smithsonian National Air and Space Museum[?], Washington DC

Operational History

March 21, 1945 - fifteern Ohka carrying Betty bombers escorted by about thirty Zeros fly to attack Taskgroup 58.1 (USS Hornet, USS Bennington, USS Wasp, USS Belleau Wood[?]). Attack force intercepted and destroyed some 70 miles from the target. None of the Bettys return.

April 1, 1945 - Six Bettys attack the US Fleet off Okinawa. At least one makes a sucessful attack, with its Ohka hitting one of the 16" turrets on the USS West Virginia, causing extensive damage. USS Alpine[?], USS Achernar[?], and USS Tyrrell[?] are also hit by kamikaze aircraft, but it is unclear whether any of these were Ohkas from the other Bettys. None of the Bettys return.

April 12, 1945 - nine Bettys attack the US Fleet off Okinawa. [[USS Mannert L Abele]] is hit, breaks in two, and sinks. USS Jeffers[?] destroys an Ohka with AA fire fifty yards from the ship, but the resulting explosion is still powerful enough to cause extensive damage, forcing the Jeffers to withdraw. USS Stanly[?] is targeted by two Ohkas. One strikes just above the waterline, with the charge punching through the other side of the hull before detonating, causing little damage to the ship, and the other Ohka narrowly missed (collecting the Stanly's ensign!) and crashed into the sea. One Betty returns.

April 14, 1945 - seven Bettys attack the US Fleet off Okinawa. None return. None of the Ohkas appear to have been launched.

April 16, 1945 - six Bettys attack the US Fleet off Okinawa. Two return, but no Ohkas hit their targets.

April 28, 1945 - four Bettys attack the US Fleet off Okinawa at night. One returns. No hits.

May 4, 1945 - seven Bettys attack the US Fleet off Okinawa. One Ohka hits the bridge of the USS Shea[?], causing extensive damage and casualties. Vessel judged beyond repair. The USS Gayety[?] is also damaged by a near-miss by an Ohka. One Betty returns.

May 11, 1945 - Four Bettys attack the US Fleet off Okinawa. USS Hugh W Hadley[?] is hit, suffers extensive damage and flooding. Vessel judged beyond repair.

May 25, 1945 - eleven Bettys attack the US Fleet off Okinawa. Bad weather forces most of the aircraft to turn back, and none of the others score hits.

June 22, 1945 - six Bettys attack the US Fleet off Okinawa. Two return, but no hits were scored.

Technical Summary