An autogyro is a type of aircraft characterized by a free-spinning horizontal rotor that turns due to passage of air upward through the blades. Whereas a helicopter achieves lift with powered rotor blades that push air downward, an autogyro’s rotor is driven by aerodynamic forces alone. Invented by Spanish engineer Juan de la Cierva and first flown in 1923, the autogyro gained popularity before it was eclipsed by the more practical helicopter. What is the top speed reached by an autogyro? Discuss
Source: The Free Dictionary