 An old method of powering free flight models is Alphonse Pénaud's elastic motor, essentially a long rubber band that is wound up prior to flight.It is the most widely used powerplant for model aircraft, found on everything from children's toys to serious competition models.The elastic motor offers extreme simplicity and survivability, but suffers from limited running time, and the fact that the initial high torque of a fully wound motor drops sharply before 'plateauing' to a more steady output, until finally declining as the final turns unwind.