In 1942 the Sikorsky R-4 became the first helicopter to reach full-scale production. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL (Vertical TakeOff and Landing) aircraft cannot perform. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors.
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