gyrodyne

thumb|upright=1.35|A Fairey FB-1 Gyrodyne

A gyrodyne is a type of VTOL aircraft with a helicopter rotor-like system that needs to be driven by its engine only for takeoff and landing, and includes one or more conventional propeller or jet engines to provide thrust during cruising flight. During forward flight the rotor is unpowered and free-spinning, like an autogyro (but unlike a compound helicopter), and lift is provided by a combination of the rotor and conventional wings. The gyrodyne is one of a number of similar concepts which attempt to combine helicopter-like low-speed performance with conventional fixed-wing high-speeds, including tiltrotors and tiltwings.