The first aerosans may have been built by young Igor Sikorsky in 1909–10, before he built multi-engine airplanes and helicopters. They were very light plywood vehicles on skis, propelled by old airplane engines and propellers.

Military aerosans

Military use of the aerosan goes back to at least the 1920s. During the 1939–40 Winter War against Finland, some were equipped with a machine-gun ring mount on the roof. They could carry four to five men, and tow four more on skis. The aerosans were initially used for transport, liaison, and medical evacuation in deep snow, and mostly used in open country and on frozen lakes and rivers because of their poor hill-climbing ability and limited manoeuvrability on winding forest roads.

During WWII, aerosans were found to be useful for reconnaissance and light raiding in northern areas, thanks to their high mobility in deep snow (25–35 km/h, where many vehicles couldn't move at all). Responsibility for aerosans was transferred to the Soviet Armoured Forces (GABTU) and orders were submitted for design and fabrication of lightly-armoured versions, protected by ten millimetres of steel plate on front. They were organized into transport or combat battalions of 45 vehicles, in three companies, often employed in co-operation with ski infantry. Troops were usually carried or towed by transport aerosans, while fire support was provided by the heavier machine gun-armed, armoured models. Aerosans were not used for direct assault because of their vulnerability to explosives such as mortar rounds.

The ANT-I through ANT-V were a successful series of aerosans of the 1920s and ’30s, designed by aircraft engineer Andrei Tupolev. The first military aerosans used in Finland, the KM-5 and OSGA-6 (later called NKL-6), were initially built at the Narkomles Factory in Moscow. During WWII, improved NKL-16/41 and NKL-16/42 models were built, and production started at the ZiS and GAZ car factories, and at smaller industries such as the Stalingrad Bekietovskiy Wood Works. In 1941 the armoured NKL-26, designed by M. Andreyev, started production at Narkomles. The following year, Gorki Narkorechflota developed the smaller, unarmoured GAZ-98, or RF-8, powered by a GAZ-M1 truck engine and durable metal propeller. There was also an ASD-400 heavy assault sled used in WWII.

Reference:

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