Do your skis retract up and rest against the belly of the plane or are they fixed?
If they're fixed, I'm sure there's a way to tuck them up so they would lay flat against the belly 'eh? There's quite a speed gain with the gear up and I would say at 20km or maybe more!

My buddy saw this thread and he was talking about putting skis on his "Moooover" that I built last winter. We just might have to do it!
Myles