Technically, wyverns do have wings; they just have two legs instead of four. I think wingless dragons would be called 'wyrms', but I'm not entirely sure on that.



The way you got them all airborne does make sense. As someone else already pointed out, Twilight does know a (very difficult) spell to produce magic wings. Pinkie has gotten herself airborne using balloons at least once, so a 'party-chute' easily fits as well.