A balloon helicopter is a toy helicopter made of a latex balloon

Balloon

A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

 and a plastic propeller

Propeller (aircraft)

Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...

. The most important feature is the hollow propeller hub which directs air into a passage in each propeller blade. The air passages channel air to the blade tips such that air escapes in a fine jet tangentially. The air jets on the blade tips causes the entire toy to spin, the blades have a positive angle of attack so the blades experience a lifting force as they push air downwards. It can attain a height of approximately 12 meters (40 feet). Full-scale helicopters have been built around this tip jet configuration.

External links

• http://video.google.com/videoplay?docid=1410167926297575940 Physics teacher Robert Douglas discusses Newton's Third Law and understanding force pairs with this demonstration using the Balloon Helicopter
• http://www.youtube.com/watch?v=rtBWcSkpC3k A demonstration video of assembly and launch.