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They have been fitting skis to planes pretty much since the beginning of airplanes. All the C-130 Hercules Aircraft that supply McMurdo in antartica have skis.

Labled for re-use and wiki-commons:

New York 109th Airlift Wing LC-130 Hercules

howdy sir bashadow! well I knew they had skis for water but I never thought about having them for ice and I still don't know how they keep from spinning around or going sideways! lol.

And I never knew that planes THAT big were fitted with skis! wow.
thanks for the education sir bashadow!