Meet the rocket-powered kamikaze: the Yukosuka MXY7 Ohka

It was a human-guided rocket bomb.
Christopher McFadden
The Yukosuka MXY7 Ohka must have been a terrifying sight. National Air and Space Museum

One of the most iconic images of the war in the Pacific during WW2 is the strategy employed by the Empire of Japan, which involved the sacrifice of some of its young pilots in suicide ramming missions on Allied surface fleets. Over 3,000 kamikaze pilots are thought to have been specially trained and prepared for this courageous task, and Kamikaze attacks sank 34 ships and damaged hundreds of others during the war. However, many either missed their targets, aborted their attach, or were intercepted and destroyed by Allied fighters and anti-aircraft defenses. 

However, too many did make it through, resulting in the Allies losing around 7,000 naval personnel. Most of you are probably familiar with the use of the iconic Mitsubishi A6M "Zero" as the plane of choice, but, towards the end of the war, pilots began to use a new kind of rocket-powered aircraft specially built for suicide attacks and launched from bombers - the Yukosuka MXY-7 Ohka.

A seemingly insane idea on the surface, these planes were actually developed, built, and thrown against the defenses of the mighty Allied fleets of the Pacific theatre. 

But were they effective? Let's find out.  

What was the name of the Japanese Kamikaze Rocket?

The infamous Japanese kamikaze rocket was called the Yokosuka MXY-7 Ohka (meaning "cherry blossom"). The aircraft was also dubbed "Baka Bombs" by Allied troops. "Baka" comes from the Japanese for "foolish" or "idiotic", since the strategy of using them was, in the view of the Allies, foolhardy. 

ohka stripped down
Image of U.S. personnel disarming an Ohka, circa 1945. Note the size of the warhead. Source: Makthorpe/Wikimedia Commons

It was a purpose-built, rocket-powered human-guided kamikaze attack aircraft developed and used by Japan against Allied ships during World War II's Pacific War. Despite its high speed, the Ohka's relatively low range required it to be carried into battle as a "parasite aircraft" by a larger aircraft, like the Mitsubishi G4M2e Model 24 "Betty" bomber.

This proved to be a severe weakness as it made them very susceptible to carrier-borne fighter interception.

Once released from the carrier aircraft, the Ohka would first glide towards its target, and when they got close enough, the pilot would fire up the craft's three solid-fuel rockets. This could be done one at a time or all in unison.

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With the rocket ignited, the pilot would then fly the missile towards the ship he intended to destroy and do everything they could to hit it. This was, needless to say, a lot harder than it sounds. 

But, for the target, the high speed that the rockets provided made it very difficult to counter the threat. Because the aircraft could reach speeds over 400 mph (650 kph) in level flight and 580 mph (930 kph) or greater when in a dive, it was challenging for defenders to zero in and knock out the incoming guided missile.

However, Ohkas could sink or damage some escort vessels and transport ships during the Battle of Okinawa in 1945, but no large warships were ever sunk. Improved versions that sought to address the plane's flaws were created too late to be deployed. 

For example, on April 12, 1945, the Allen M. Sumner-class destroyer USS Mannert L. Abele became the first Allied ship casualty of the Ohka as it lurked in the waters off Okinawa. Over the entire operational history of the craft, Ohkas managed to sink or damage three ships beyond repair and badly damaged three more, racking up a total of seven U.S. ships damaged or sunk by Ohkas during the war.

ohka model 22
A surviving example of a later model, a Model 22. Source: Sanjay Acharya/Wikimedia Commons

Throughout the war, somewhere in the region, 34 Allied ships were sunk (a mixture of destroyers, mine sweepers, and some larger capital ships and support ships). While hundreds of others were damaged using kamikaze attacks—a paltry sum for the loss of thousands of young lives spent. 

Several variants of the Ohka were designed, built, and tested, but, by far, the most numerous were the Ohka-11 variant. 

This was, essentially, a 2,600 pound (1,200-kilogram) bomb with wooden wings, powered by three Type 4 Model 1 Mark 20 solid-fuel rocket engines. Of all the Ohka built, somewhere in the region of 755 Ohka-11 were built. 

Other variants were developed with mixed success, but only the Ohka-11 actually saw active service. Later versions of the Ohka were intended to be launched from coastal air bases and caves and submarines with aircraft catapults, although none were ever utilized in this manner.

Vital states of the Yokosuka MXY-7 Ohka

Since there were a series of variants, we'll provide the details for the most common version, the Ohka-11. 

First flight: First unpowered flight March 1944, first powered flight November 1944

Introduction: 1945

Retirement: 1945

Wingspan: 16 feet and 10 inches (5.12 meters)

Length: 19 feet and 11 inches (6.066 meters)

Propulsion: 3 no. Type 4 Mark 1 Model 20 solid-propellant rocket motors, 588 pounds/foot (2.62 kN) thrust each

Top speed: 403 mph (648 kph) at 11,483 feet (3,500 meters) altitude

Range: 23 miles (37 km)

Armament: One 2,600 pound (1,200 kg) Ammonal warhead in the nose. Ammonal is an explosive made up of ammonium nitrate and aluminum powder. 

Crew: 1 kamikaze pilot

Number built: Circa 852

Notes: Classified as a piloted (suicide) anti-ship aircraft/human-guided missile

What is a kamikaze-style attack?

During World War II, kamikaze ("divine wind") style attacks were a Japanese suicide bombing strategy used to destroy opposing surface ships (the attacks were also used against the B-29 Superfortress, but with very little success).

Pilots would fly their specially adapted aircraft (like the Mitsibushi "Zero") intentionally towards and into enemy ships. 

ohka mark 11
A surviving example of Ohka Model 11. Source: Planes of Fame Air Museum

Suicide attacks by Japanese pilots were also observed in the earlier stages of the War in the Pacific, but more as a kind of last-ditch, desperate sacrifice once their aircraft was mortally wounded. For example. During the Attack on Pearl Harbor in 1941, several pilots used their damaged aircraft as ad hoc flying explosives. 

But these were not kamikaze attacks. In fact, Allied and Luftwaffe pilots are also known to have done similar things with their damaged planes. It was rare, but it did happen. 

"True" kamikaze attacks, that is, attacks using specifically trained pilots in specially adapted aircraft, didn't really begin until around the fall of 1944. 

At this point in the war, the tides of war had turned against Imperial Japan. Japanese forces were experimenting with many tactics to attempt to cause as much damage as possible to advancing Allied forces with the dwindling resources they had. 

Kamikaze attacks, including those using Yokosuka MXY-7 Ohka, ultimately had little impact on the war's outcome. While a fearsome attack to face as the defender, tactics were quickly developed to counter them, rendering the entire endeavor completely reckless, or "Baka", as the allies would come to mockingly call it. 

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