No, it’s not helicopters. Speech will go today about snakes. You ask: can l find something in common between these very different devices? It is possible… the fact that the serpent flies by created any element of the lifting force, be it habitual plate, box frame, covered with paper, or something else. In short — you need a lifting force. And for its creation can be as “something else” to come and propeller similar to a helicopter, or the wheel of Magnus. What kind of wheel? Explain in more detail.
German scientist G. Magnus in 1852 discovered the effect of air flow in the rotating pipe: the incident on the pipe transversely to the axis of the jet is deflected in the direction of the seam. There were even attempts to use this effect on the ship: regular sails tried to replace the tall hollow tubes. They move with the propulsion system, and lateral wind deflected back cylinders-sails, have created a kind of jet thrust.
But the snake put the engine seems to be useless, so we need to solve the problem — how to get the reels spinning. Again we turn to history and remember that Savonius was known as the inventor of the self-rotating drum. He cut the cylinder in half along the axis and displaced by these halves relative to each other. Thus it is said spinner, one part where the air flows about and the other as if it rakes in his “pocket”, creating resistance. This difference causes the drum to spin. At the same time manifested the effect of education lift.