The aircraft was 6.07 metres long. It carried a 1,200-kilogram warhead in its nose. The cockpit held only rudimentary instruments — an airspeed indicator, an altimeter, an attitude indicator — and the controls to fire three solid-fuel rocket motors. There was no landing gear. There was no parachute. The pilot was never expected to return.

The Yokosuka MXY-7 Ohka — Japanese for “cherry blossom” — was the first purpose-built suicide aircraft in history. The Allies, who fought it from March 1945 until the end of the war, called it Baka. The word translates as “fool.”

A Weapon Born of Desperation

By autumn 1944 Japan was losing on every front. The American B-29 raids were accelerating. Allied submarine warfare had cut off Japanese oil supplies. Conventional kamikaze pilots — fighters loaded with explosives and flown directly into Allied warships — were achieving real results, but the aircraft were obsolete and slow. American carrier-based combat air patrols were shooting them down before they reached their targets.

A junior officer, Ensign Mitsuo Ohta, proposed a different approach, developed by the Yokosuka Naval Air Technical Arsenal — the Kugisho: build an aircraft optimised purely for the suicide mission. Cheap. Fast. Hard to intercept. Carried to the target by a conventional bomber. The pilot would only have to fly the last few minutes — the part where speed and inevitability mattered most.

How It Worked

An Ohka mission began with a Mitsubishi G4M “Betty” twin-engine bomber, modified with an Ohka clamped under the bomb bay. The Betty climbed to altitude and approached the target fleet. At roughly 30 to 35 kilometres from the target, the Ohka pilot — who rode in the bomber and climbed through the bomb bay into his cramped cockpit shortly before the attack — was released.

The Ohka glided downward, building speed. Once aligned with the target, the pilot ignited the rocket motors. The little aircraft accelerated to 650 km/h horizontally, then transitioned into a terminal dive approaching 1,000 km/h — faster than any Allied fighter could catch. The warhead was fused to detonate on impact.

One Ohka strike on the destroyer USS Mannert L. Abele on 12 April 1945 killed 84 men and broke the ship in half. It was the first warship in history sunk by a piloted missile — and the only one the Ohka ever sank outright.

The Allied Counter

The American counter-strategy was simple: kill the bombers before they could release. The Ohka had no usable range without its mothership. The G4M Betty, weighed down by an Ohka, was 50 km/h slower than normal and could not manoeuvre. American F6F Hellcats and F4U Corsairs were given strict instructions to focus fire on Bettys carrying Ohkas, and to ignore unloaded escort fighters until the Ohka was destroyed.

The strategy worked. Of the roughly 300 Ohkas available for the Okinawa campaign, only 74 were ever carried into action, and just seven US ships were sunk or damaged by them. The vast majority were destroyed in their motherships before release.

The Pilots

The Ohka programme drew its pilots from the same pool as the conventional kamikaze units. Most were university students conscripted in 1944. Their training was minimal — the aircraft was, after all, designed for one flight only. Many never got to make even that flight; their motherships were shot down before release, killing the Ohka pilot along with the bomber crew.

More than a dozen Ohkas survive in museums today, from Tokyo to London to Washington. Each is small, neat, and unsettlingly cheerful in appearance — a reminder that the most cruel weapons in aviation history are not always the largest.

Sources: Imperial War Museum, National Air and Space Museum, “Suicide Squads” by Richard O’Neill.