A helicopter is an aircraft that is supported and propelled by one or more horizontal rotors, each consisting of two or more blades. Helicopters are classified as rotating-wing aircraft, to distinguish them from fixed-wing aircraft, because helicopters create lift with blades that rotate around a vertical axis.The word “helicopter” derives from the French term helicoptère, coined by the Aviation pioneer Gustave Ponton d'Amécourt in 1863 from the Greek word ελικόπτερος, helix / helik- (helix) and pteron (wing).
The main advantage of helicopters is given by the rotor, which provides lift without the aircraft moving. This allows vertical take-offs and landings without the need for a runway. For this reason, helicopters are often used in congested or isolated areas where airplanes cannot take off or land. The lift of the rotor also makes it possible for the helicopter to keep flying in an area much more efficiently than another VTOL (vertical take-off and landing) aircraft could, and being able to perform tasks that a fixed-wing aircraft could not.
The first take-off and controlled vertical landing is the merit of the Argentine inventor Raúl Pateras de Pescara, who, on February 21, 1920, patented in Spain his helicopter design with counter-rotating blades. It was the first autogyro capable of being controlled in flight, unlike its predecessors who had no practical use for suffering from uncontrolled vibrations and turns shortly after taking off. Raúl Pateras de Pescara was also a pioneer in the use of self-rotation for safe landings in the event of a helicopter breakdown.
Mount Everest is the highest mountain on planet Earth, with an altitude of 8,848 meters (29,029 feet) above sea level. It is located on the Asian continent, in the Himalayas, specifically in the sub-mountain range of Mahalangur Himal; it marks the border between China and Nepal, considered the highest border in the world.  The massif includes the neighboring Lhotse peaks, 8516 m (27 940 ft); Nuptse, 7855 m (25,771 feet) and Changtse, 7580 m (24,870 feet).