An autogyro, or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. While similar to a helicopter rotor in appearance, the autogyro's unpowered rotor disc must have air flowing upward across it to make it rotate.
A modern, closed-cabin, pusher-propeller autogyro in flight
The rotor head, pre-rotator shaft, and Subaru engine configuration on a VPM M-16 autogyro
Russian Gyroplanes Gyros-2 Smartflier
Montgomerie Merlin single-seat autogyro
A rotorcraft or rotary-wing aircraft is a heavier-than-air aircraft with rotary wings or rotor blades, which generate lift by rotating around a vertical mast. Several rotor blades mounted on a single mast are referred to as a rotor. The International Civil Aviation Organization (ICAO) defines a rotorcraft as "supported in flight by the reactions of the air on one or more rotors".
A Bell 47 helicopter, an early example of a powered rotorcraft
A Bell UH-1 Iroquois helicopter
A Magni M-16 Tandem Trainer autogyro
A Fairey Rotodyne prototype gyrodyne