Yeah, I couldn't tell what was happening with my planes when they were doing that. I think it was partly wheels, but I also figured that it was partly the flaps, that they weren't all going the same direction when I placed them. There was one set of flaps - I think they went on the wings - which NEVER seemed to go the right direction no matter how I put them on (unless they were right and all the other ones were wrong). In any case, I've had about 2 successful takeoffs in about 30 tries, which is one reason I don't spend a lot of time making space planes, heh