The Antonov A-40 Krylya Tanka (Russian: крылья танка, meaning "tank wings") was a Soviet attempt to allow a tank to glide into 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. This vehicle is sometimes called the A-40T or KT.
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 the 1940 occupation of Bessarabia, light tanks may have been dropped from a few metres by TB-3 bombers, allowing them to roll to a stop with the gearbox in neutral.

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 needn't appear over the battlefield. So the Soviet Air Force ordered Oleg Antonov to design a glider for landing tanks.
TB-3 bomber carrying a T-27 tankette, 1935

Antonov was more ambitious, and instead of building a glider added a detachable cradle to a T-60 light tank, bearing large wood and fabric biplane wings and 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 Tupolev TB-3. The tank was lightened for air use by removing armament, ammunition, 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). A-40 was piloted by the famous Soviet glider experimental pilot Sergei Anokhin. The T-60 landed on 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 sufficiently-powerful aircraft to tow it at the required 160 km/h, the project was abandoned.