It is the kind of idea that should never have left the napkin. Take a small tank, weighing roughly 5.5 tonnes. Bolt on a biplane-style wing and a twin-boom tail. Tow the assembly into the air behind a heavy bomber. Cast it off over enemy lines. Let the tank glide down. Have the crew, sitting inside the running tank, jettison the wings on landing and drive into combat.

This is the Antonov A-40 — also known as the Krylya Tanka, "Tank Wings" — and the Soviet Union actually built it. It actually flew. Once.

A Problem Looking for an Idea

By 1941, the Soviet Union had a partisan-supply problem. Operating behind German lines required either parachute-dropping individual soldiers (slow, dispersed) or landing transport aircraft on hastily-cleared strips (suicidal). What partisan forces actually needed were vehicles — small, armoured, mobile vehicles that could go directly from airdrop to combat.

Oleg Antonov, then a 36-year-old glider designer who would later run the Soviet Union's premier transport-aircraft bureau, proposed the obvious-once-you-saw-it solution. Make the tank itself fly.

The Aircraft

The A-40 paired a stripped-down T-60 tank — armament and ammunition removed, fuel strictly limited — with a detachable wing/tail unit. The wings were big: nearly 60 feet across, biplane configuration, fabric-covered, very simple. A twin-boom empennage gave control surfaces a long arm. The tank's tracks were the landing gear. The tank's driver was the pilot, sitting in the normal driver's seat and operating the glider's controls through a converted yoke.

The intended sequence was elegant. A heavy bomber would tow the assembly to altitude, head deep into enemy territory, release the A-40 on a glide path toward partisans below. The tank would glide down, touch its tracks to the ground, slow to a stop, the crew would jettison the wing assembly with a mechanical release, and the tank would drive off to fight.

The Flight

On 2 September 1942, test pilot Sergei Anokhin climbed into the driver's compartment. A Tupolev TB-3 — four engines, slow, draggy, and the largest tow aircraft in the Soviet inventory — wound up its engines and pulled. The A-40 lifted off. It actually flew.

And then the TB-3's engines started overheating. The combined drag of the tank-with-wings was simply too much. The tow pilot, watching his oil-temperature needles climb past the red, told Anokhin he was being released. Anokhin cast off and glided down. He landed in a field, applied the brakes (the tank's tracks were now his rollout brakes), came to a stop — and then did exactly what the design intended.

Anokhin jettisoned the wing and tail assembly, and the T-60 drove back to its base under its own power. It was the only time the trick was ever performed: there was no Soviet tow aircraft powerful enough to tow the A-40 operationally, and the program was quietly cancelled.

Why It Still Matters

The A-40 is one of aviation's great "what if" moments. The idea was sound — an armoured vehicle dropped intact into a battle is a force multiplier — but the tow technology of the 1940s could not match the ambition. Within a decade, helicopters would solve the same problem more elegantly.

Oleg Antonov went on to design every major Soviet transport aircraft of the post-war era, up to and including the An-225 Mriya, the largest aircraft ever built. The A-40 stayed an experiment, a fine entry in the long list of ideas the Soviet Union tested anyway. It flew once. That is more than most ideas like it ever managed.

The full story of the Soviet flying tank — Antonov A-40.

Sources: Antonov Design Bureau archives, “OKB Antonov: A History of the Design Bureau” (Yefim Gordon), declassified Soviet test reports.