1. Propeller Toy Wow it really flies, indoors and outside! Just move your hands in opposite directions and the lightweight and durable propeller toy flies into a fast vertical flight. A great demonstration of the physics of lift and flight

2. How do helicopter propellers work? The Main rotor blades of a helicopter are basically airfoils that are kept in constant motion by rotating around a central shaft. Like wings on an airplane they use Bernoulli's principle to generate lift. The upper surface of a helicopter blade is curved while the lower surface is flat. This means air has a longer distance to travel when it flows over the top of the blade. since the air has longer to travel over the blade than under it, air generally moves faster when it's pushed over the top of the blade. this creates a low pressure area on top of the blade, which generates lift ( high pressure on bottom of blade tries to move to low pressure on top of blade).

3. This classic Flying Propeller was well known wooden toy when Leonardo da Vinci was a child. Leonardo speculated that man could fly with similar screw mechanisms!

4. Orville and Wilbur Wright played with versions of this toy when they were boys. Their first flight used this propeller shape to pull the Wright Flyer into history.

5. How do mini Helicopters fly http://www.minihelicopter.net/howd ohelicoptersfly/index.htm

6. The Helicopter A good basic source on how helicopters work in the book By David Macaulay called The Way Things Work. Look for the section on The Helicopter, Single Rotor Helicopter and Twin Rotor Helicopter. He does a good job of explaining the basics.

7. http://www.stefanv.com/rcstuff/qf200203.ht ml http://www.stefanv.com/rcstuff/qf200203.ht ml