RC aircraft with impeller

Impeller

— a kind of substitute for a propeller, used mainly in copies of jet aircraft. The impeller is a wheel of small narrow blades enclosed in a ring; such a device can be hidden in a dummy turbine, giving the device a complete external resemblance to a jet prototype. There are other applications for the impeller — for example, on top of a flying wing — but they are rare, because. such propellers are more complicated and more expensive than conventional propellers.