Things You'll Need
Instructions
Tie the string into a loop about the size of a standard rubber band.
Thread the loop between the strands of rubber band that run from the propeller to the back of the plane. The plane will fly best if you center the payload under the wings.
Wind the propeller until the loop is trapped between the strands of rubber band.
Tie or hook the payload to one side of the loop. Leave the other side of the loop alone, so that it will slip free of the rubber strands when they unwind during flight.
Release the propeller and launch the plane. The rubber strands unwind as the propeller spins, and the decreased tension allows the payload to slip free.