There is not real reason to put skis on a plane if there is no snow. It is set up by using a single axis pivoting frame with a child of a fuselage. To make the ski go nose high in flight and "level out" to the ground when it is touching it. there is no real other way and the skis cannot be touching the ground in to places it makes them go nuts. so it needs wheels to hold the weight.
I think I am the only one who has used the single axis Pivoting frame. Some other people may have use it a couple of times But I think I have used it the most