The rubberband-powered helicopter is easy to construct, and with a little practice it can be flown 20+ feet into the air!
How It Works:
1. Energy is stored in the sport rubber by winding the propeller.
2. When flown, the rubberband rapidly releases its energy by unwinding, which turns both the propeller blade and the paper cutout.
3. The paper cutout pushes against the surrounding air, which creates horizontal air resistance, or drag. This makes it harder for the cutout to spin. Because the cutout does not spin as easily, more energy from the rubberband is released into the propeller, which is much easier to turn. In this way, the paper acts like the rear rotor of a real helicopter
4. As the propeller spins rapidly, it begins to create lift by pushing air downward. With enough energy, the helicopter will fly in whatever direction it is pointing.