An aerosan (literally 'aerosleds') is a type of propeller-powered snowmobile, running on skis, used for communications, mail deliveries, medical aid, emergency recovery and border patrolling in northern Russia, as well as for recreation. Aerosans were used by the Soviet Red Army during the Winter War and the Second World War. 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 vehic… (More on Aerosan)