Above: Amelia Earheart and an Autogyro close up
the propeller pulls it through the air, the helicopter blades weren't powered and started spinning as the plane acquired forward momentum, and provided lift... notice that there aren't wings on the planes in the top and bottom photos. .a helicopter works by forcing the rotor blades through the air, pushing air downwards, the autogyro rotor blade generates lift in the same way as a glider's wing by changing the angle of the air as it moves upwards and backwards relative to the rotor blade. The free-spinning blades turn by autorotation; the rotor blades are angled so that they not only give lift, but the angle of the blades causes the lift to accelerate the blades' rotation rate, until the rotor turns at a stable speed with the drag and thrust forces in balance. http://en.wikipedia.org/wiki/Autogyro