The Soviet flying tank A-40

The Antonov A-40  was a Soviet attempt to allow a tank to glide onto a battlefield after being towed aloft by an airplane, to support airborne forces or partisans. A prototype was built and tested in 1942, but was found to be unworkable. Instead of loading light tanks onto gliders, as other nations had done, Soviet airborne forces had strapped T-27 tankettes underneath heavy bombers and landed them on airfields. In the 1930s there were experimental efforts to parachute tanks or simply drop them into water. During the1940 occupation of Bessarabia, light tanks may have been dropped from a few meters up by TB-3 bombers, which as long as the gearbox was in neutral, would allow them to roll to a stop.

The biggest problem with air-dropping vehicles is that their crews drop separately, and may be delayed or prevented from bringing them into action. Gliders allow crews to arrive at the drop zone along with their vehicles. They also minimize exposure of the valuable towing aircraft, which need not appear over the battlefield. So the Soviet Air Force ordered Oleg Antonov to design a glider for landing tanks. Antonov was more ambitious. Instead of building a glider, he added a detachable cradle to a T-60 light tank bearing large wood and fabric biplane wings and a twin tail. Such a tank could glide into the battlefield, drop its wings, and be ready to fight within minutes.

One T-60 was converted into a glider in 1942, intended to be towed by a Petlyakov Pe-8 or a Tupolev TB-3. The tank was lightened for air use by removing its armament, ammunition and headlights, and leaving a very limited amount of fuel. Even with the modifications, the TB-3 bomber had to ditch the glider during its only flight, on September 2, 1942, to avoid crashing, due to the T-60's extreme drag (although the tank reportedly glided smoothly). The A-40 was piloted by the famous Soviet experimental glider pilot Sergei Anokhin. 

Sergei Anokhin, test pilot (1910-1986)

The T-60 landed in a field near the airdrome, and after dropping the glider wings and tail, the driver returned it to its base. Due to the lack of a sufficiently-powerful aircraft to tow it at the required 160 km/h (99 mph), the project was abandoned.

You may found more about A-40 in following books:

1. Gunston, Bill (1995). The Osprey Encyclopedia of Russian Aircraft 1875–1995. London: Osprey.

2. Zaloga, Steven J.; James Grandsen (1984). Soviet Tanks and Combat Vehicles of World War Two. London: Arms and Armour Press.