gyrodyne

A gyrodyne is a type of VTOL aircraft with a helicopter rotor-like system that is driven by its engine for takeoff and landing and also includes one or more conventional propellers to provide forward thrust during cruising flight. Lift during forward flight is provided by a combination of the rotor, like an autogyro, as well as conventional wings. Due to a number of issues, there is some confusion over the term "gyrodyne", and the terms compound helicopter and compound gyroplane are frequently used to describe the same design. The gyrodyne is one of a number of similar concepts which attempt to provide helicopter-like low-speed performance and conventional fixed-wing high-speeds, including tiltrotors and tiltwings.