Helicopter

A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway. In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production. Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter, not to be confused with the single-blade monocopter) has become the most common helicopter configuration. However, twin-main rotor helicopters (bicopters), in either tandem or transverse rotors configurations, are sometimes in use due to their greater payload capacity than the monorotor design, and coaxial-rotor, tiltrotor, and compound helicopters are also all flying today. Quadrotor helicopters (quadcopters) were pioneered as early as 1907 in France, and along with other types of multicopters, have been developed mainly for specialized applications such as drones. The English word helicopter is adapted from the French word hélicoptère, coined by Gustave Ponton d'Amécourt in 1861, which originates from the Greek helix (ἕλιξ) "helix, spiral, whirl, convolution" and pteron (πτερόν) "wing". For various reasons, the word is often erroneously, from an etymological point of view, analysed by English speakers into heli- and copter, leading to words like helipad and quadcopter. English language nicknames for "helicopter" include "chopper", "copter", "heli", and "whirlybird". In the United States military, the common slang is "helo" pronounced with a long "e". A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more horizontally-spinning rotors.