Ohka – Kamikaze Plane
The Yokosuka MXY7 Ohka was the only purpose-built suicide aircraft ever deployed. Other suicide aircraft were designed and built for other purposes. The MXY7 was rocket powered. It had a 1,200-kilogram warhead. A modified Mitsubishi G4M2e Model 24[i] bomber would fly to within about 40 kilometers (25 miles) of the target ship. The bomber would drop the Ohka and the Ohka pilot would start the rocket engine and attempt to crash the Ohka into an allied ship. In Japanese “Ohka” means “Cherry Blossom”. U.S. Navy sailors nicknamed the aircraft “Baka” which is Japanese for “Fool”.which is Japanese for “Fool”.
[i] The G4M2e modified to carry the Ohka had the nicknames “Otsu” and “Hei”. The Allied codename for the G4M2 was “Betty”.
Development and Combat
The Ohka made its first unpowered flight in October 1944 and made the first powered flight in November.[i] The Ohka was a simple plane to fly. Pilots were given one or two unpowered training flights.
The first mission for the Ohka was March 21, 1945. U.S. Navy F6F Hellcats shot down the 16 bombers carrying the Ohkas before they were close enough to the fleet. The Hellcats also shot down the two bombers used for radio and navigation and 15 of the 30 Zero escorts.[ii] The Japanese carried out massive kamikaze, including Ohka, attacks off Okinawa on April 1. The kamikazes sank and damaged many ships. it’s uncertain if any damage was from an Ohka attack. The battleship USS West Virginia was one of the ships damaged. A least one source claims an Ohka struck the USS West Virginia[iii] but this doesn’t seem consistent with reports of the attack that caused the damage.
On April 12, 1945 an Ohka struck and sank the destroyer USS Mannert L. Abele. The ship had a crew of over 300, 73 of the USS Abele crew died in the sinking.[iv] The USS William N. Jeffers shot down an Ohka. The exploding Ohka caused enough damage to force the USS Jeffers to withdraw.[v] Two Ohka attacked the destroyer USS Stanly. One struck the USS Stanly but caused little damage.[vi]
On May 4 an Ohka struck and heavily damaged the minesweeper USS Shea. The attack killed 27 crew members and wounded 91.[vii] The USS Gayety shot down an Ohka. The kamikaze crashed and exploded close to the USS Gayety. Shrapnel from the explosion wounded three sailors and disabled a 40mm gun.[viii] The last successful Ohka attack was on the destroyer USS Hugh W. Hadley. The USS Hadley was hit by 2 bombs and 3 kamikazes, at least one was an Ohka. The USS Hadley was damaged beyond repair. The attacks killed 30 and wounded 121 of the Hadley crew.[ix]
[i] Aces Flying High, https://acesflyinghigh.wordpress.com/2015/09/02/yokosuka-mxy7-ohka-the-height-of-kamikaze-madness-in-1945/, last accessed, 10/13/19.
[ii] Indiana Military.org, Fuji Kokuki K.K. Baka (Jet) N50, http://www.indianamilitary.org/FreemanAAF/Aircraft%20-%20Japanese/N%200050%20Jet%20Baka/Jap%200050.htm, last accessed 10/13/19.
[iii] Aces Flying High, https://acesflyinghigh.wordpress.com/2015/09/02/yokosuka-mxy7-ohka-the-height-of-kamikaze-madness-in-1945/, last accessed, 10/13/19.
[iv] Unofficial U.S. Navy Site, USS Mannert L. Abele, https://www.navysite.de/dd/dd733.htm, last accessed, 10/13/19.
[v] Everything Explained Today, USS William N. Jeffers Explained, https://everything.explained.today/USS_Jeffers_(DD-621)/, last accessed, 10/16/19.
[vi] History.Navy.mil, USS Stanly (D-478), https://www.history.navy.mil/research/histories/ship-histories/danfs/s/stanly.html, last accessed, 10/16/19.
[vii] U-Boat.net, USS Shea (DM30), https://uboat.net/allies/warships/ship/2108.html, last accessed 10/16/19.
[viii] HistoryCentral, Gayety AM-329, https://www.historycentral.com/navy/Minelayer/Gayety.html, last accessed 10/16/19.
[ix] USS Hadley Memorial Website, https://usshadley.net/battle-damage/, last accessed 10/16/19.
Further Development and What Might Have Been
Range was the Ohka 11’s major shortcoming. The Ohka’s rocket engines gave it great speed at the expense of range. Kugisho developed the Ohka 22. The Ohka 22 used a hybrid motor-jet engine. The Ohka 22 range was 81 mils (130 km). It also had a smaller warhead, 1,323 lbs. (600 kgs). It was modified to fit the Yokosuka P1Y1 Ginga[i]. The Ginga was faster than the Mitsubishi G4M which carried the Ohka 11. Kugisho completed 50 Model 22 airframes and three engines before the war ended.[ii]
The Japanese were also developing launch ramps so they could launch the Ohkas from land to attack invading ships. The Japanese were preparing for the Allies invasion of the home islands. The Japanese military believed if they caused enough allied casualties in the initial invasion the Allies would accept a negotiated settlement. While the Japanese Army’s plans seemed unrealistic, there is historical precedence before and after World War II. A combination of high casualties and a war’s long duration could mean political trouble in America, Japan’s main adversary. In any case an invasion of Japan’s main islands would have been costly to both sides.
The Allies planned to invade the Kyushu Island in November 1945. The Allies planned to invade Honshu Island in the Spring of 1946. The Japanese military hoped to have 10,000 aircraft available for the Allied invasion. Almost all of these aircraft were going to fly kamikaze missions.[iii] The primary targets for the Kamikazes were going to be the transport ships. This means the smaller warhead of the Ohka 22 would be adequate for the task.
How many Ohkas would have been available for the invasions? How well would the Ohka 11 and Ohka 22 have performed? Thankfully these questions, and questions about how the allied invasion of Japan would have played out, is in the realm of alternate history.
[i] On April 2, 1945 a Yokosuka P1Y Ginga kamikaze struck the attack transport USS Henrico (APA-45). The attack killed the ship’s captain, Captain William C. France, and 48 others, including 14 soldiers. Many more were wounded. Henrico.org, Kamikaze Memorial, http://henricoapa45.org/kamikaze-memorial/, last accessed 10/19/19.
[ii] Smithsonian Air & Space Museum, Kugisho MXY7 Ohka (Cherry Blossom) 22, https://airandspace.si.edu/collection-objects/kugisho-mxy7-ohka-cherry-blossom-22, last accessed 10/19/19.
[iii] Operation Olympic.com, Japanese Defenses, http://www.operationolympic.com/p1_defenses.php, last accessed 10/19/19.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2019 Robert Sacchi