The "Aerosans" were light sled vehicles, propelled across the ice and snow by aircraft engines and propellers.

The Red Army had several Aerosan detachments that were employed with relative success in winter operations against the Finns during the Winter War.
They were used primarily for maintaining communications between units and formations, and ferrying ammunition, provisions, and petroleum products to forces operating at great distances from their supply bases. These sleds also evacuated the wounded from the battlefield.
Sometimes aerosled detachments executed combat missions; launching surprise attacks against the enemy.

With the beginning of the Great Patriotic War, all the aerosleds that existed in the country were mobilized into the Red Army.
Improved versions, the NKL-16/41 and NKL-16/42 were produced at the Narkomlets Factory in Moscow and proved so useful that production control was taken over by central authorities.
Production continued at the GAZ and ZiS automotive factories, as well as at smaller woodworking firms.
In December 1942, the Narkomlets Factory was commissioned to design an armoured version for scouting and raiding in areas barred by the terrain to tanks or armoured cars.

The result was the NKL-26 armoured aerosan.

Actually, armoured is a slight exaggeration since 10mm plate was only carried on the front surface, due to the inability of the vehicle to propel any more weight.
The NKL-26 aerosled was intended for the transport of a crew of two persons - the vehicle commander who simultaneously fulfilled the function of gunner in a combat environment, and the mechanic-driver.
The hull of this aerosled was made of wood and fully enclosed.
It had four independently suspended controllable skis.
Steering of the aerosled was accomplished with the aid of a steering wheel, mounted in the driver's compartment.
Through a system of levers and ropes the steering effort was imparted to all four skis, which rotated in pairs in opposite directions.

Aerosans were deployed in battalions. 3 companies of 15 each. The larger NKL-26 were normally deployed in company strength.
All these vehicles were used in frozen northern areas, especially on lakes and rivers because of the limited ability of negotiating much of a slope.