I think it is against the rules to shoot something from a plane. There is no mention of shooting at a plane. I have shot paintballs at a plane, and it is fun. You have to lead the target a bunch, and the plane has to be flying real slow. The few hits that occurred did no damage, but it was shot at a competetive open b airframe, so it was reinforced quite well. I bet balsa would disintegrate. I have shot paintballs at plain 2" 15psi building foam, and the balls go right through. sometimes without breaking. They did break on a covered foam wing though.