An autogyro (from Spanish autogiro), also known as gyroplane, gyrocopter, or rotaplane, is a type of rotorcraft which uses an unpowered rotor in autorotation to develop lift, and an engine-powered propeller, similar to that of a fixed-wing aircraft, to provide thrust. While similar to a helicopter rotor in appearance, the autogyro's rotor must have air flowing through the rotor disc in order to generate rotation. Invented by the Spanish engineer Juan de la Cierva to create an aircraft that could safely fly at slow speeds, the autogyro was first flown on 9 January 1923, at Cuatro Vientos Airfield in Madrid. De la Cierva's aircraft resembled the fixed-wing aircraft of the day, with a front-mounted engine and propeller in a tractor configuration to pull the aircraft through the air. Under license from Cierva in the 1920s and 1930s, the Pitcairn & Kellett companies made further innovations.
According to Carter Aviation Technologies, the Texas based company developing the CarterCopter the maximum theoretical speed of the craft is an incredible 500 mph (800 km/h), the current prototype reached a much more modest speed of 173 mph (270 km/h). Carter Aviation has no plans to manufacture a commercial version of the craft at this stage and is still working on perfecting the technology and hope to license the technology to experienced aircraft manufacturers in the future.