The principle that this toy is based on is how rubberbands store energy, aerodynamics, and the concept of flight.

The child will interact with the toy by winding up the propeller of the plan, adjusting the tail for desired motion, and then throwing it to help with the desired motion. I came up with this design by kind of looking at the old school toy wind up planes and the foam ones they have these days that do tricks, so i thought i would combine them to get the propeller drived version forprolonged flight. I guess the cost of construction will be pretty cheap, since it's basically made out of inexpensive parts (foam, rubberband, plasitc, etc), and the child puts it together himself. It is pretty safe since there are not sharpe edges and the propeller won't have much change of cutting since powered by a rubberband. The toy is a little less durable than plastic toys since it's made out of styrofoam, but if they break it they can always buy replacement parts.