Take off from the ground and fly away! Leonardo da Vinci's dream only became a reality centuries later when aviation pioneers like Otto von Lilienthal finally understood the laws of flight. This led to a development that, within a few decades, even made supersonic flights possible. While airplanes can never remain stationary in the air, helicopters can. They can land effortlessly on a small spot. But how does a rotor work, and what is the purpose of the small tail rotor?.