I used to enjoy making balsa and tissue paper planes, and flying them. There is an association for them, Flying Aces International with a home base in Erie, PA. I used to belong and go to the meetings and FAI meets. The planes were powered by rubber bands, which came in difference thicknesses and several strands used in the plane. There is a lot of science in the sport, and knowing just how many twists to put in the rubber band is crucial. The idea is to keep the plane flying for as long as it will. Too many twists and the bands break and destroy your plane. That was a very discouraging occurrence, and happened too often to me.