A rotorcraft is a heavier-than-air flying machine that uses lift generated by wings that revolve around a mast called rotor blades. Several rotor blades mounted to a single mast is referred to as a rotor. Rotorcraft may also include the use of static lifting surfaces, but the primary distinguishing feature being lift provided by one or more rotors. Rotorcraft include helicopters, autogyros, gyrodynes and tiltrotors. In the United States, the Federal Aviation Administration places helicopters, autogyros (which it calls gyroplanes), and gyrodynes in the category Rotorcraft, and tiltrotors in the category Powered lift.
A helicopter is a rotorcraft whose rotors are driven by the engine(s) throughout the flight, to allow the helicopter to take off vertically, hover, fly forwards, backwards and laterally, as well as to land vertically. Helicopters have several different configurations of one or more main rotors.
Helicopters with one driven main rotor require some sort of antitorque device such as a tail rotor, fantail, or NOTAR, except some rare examples of helicopters using tip jet propulsion which generates almost no torque.
Unlike a helicopter, the rotor of an autogyro (sometimes called gyrocopter or gyroplane) is driven by aerodynamic forces alone, and thrust is provided by an engine-powered propeller similar to that of a fixed-wing aircraft.
A Gyrodyne is a rotorcraft with a rotor system that is normally driven by its engine for takeoff, hovering and landing like a helicopter, but which also has an additional propulsion system that is independent of the rotor system. At higher speeds, the rotor system acts similar to that of an autogyro, no longer driving the aircraft but simply providing lift. A technology proposal by Carter Copter Technologies, as well as a research project funded by DARPA both refer to gyrodyne-type concepts as heliplanes.
Various kinds of hybrid between rotary and fixed-wing aircraft have been created:
There are also examples of hybrids between a helicopter and an airship:
Where a rotorcraft has two or more rotors, the rotors may or may not intermesh.
The difference between a ducted rotor and a ducted fan design (which is not a rotorcraft) is that when the rotor is stationary you can see through the rotor disc.
Researchers Submit Patent Application, "Rotorcraft Counter-Torque Control Assembly and Method", for Approval
Jul 24, 2013; By a News Reporter-Staff News Editor at Defense & Aerospace Week -- From Washington, D.C., VerticalNews journalists report that a...