Helicopters are aircraft whose lift comes from a large propellor rotating above the body of the aircraft. There are, actually, two rotors to balance each other. There is also a tail-mounted rotor which provides stability to the helicopter. In 1480 Leonardo da Vinci designed a helicopter, though some scholars believe that a Chinese book from the fourth century describes a rotary flying machine. Whatever the history the first helicopter to fly was in 1907 in France, when the Breguet brothers managed to lift a helicopter off the ground for one minute, though it only hovered at about two feet off the ground, although it had to be held steady by four men standing on the ground. The first "true" helicopter flight was the next year, 1908, when another Frenchman, Paul Cornu, managed to hover at a similar height for about 20 seconds, though as his craft was not held by anyone on the ground it was he world's first free flight of a helicopter.

Progress was then slow and it was not until the 1920s that further development took place. An Argentinian, Raúl Pescara, designed and flew a craft that could, by changing the pitch of the rotors, adjust the flight of the helicopter. In 1923 a Spaniard, Juan de la Cierva created a craft that would be the basis of all future helicopter development. Engineers in Italy, France and Russia continued to develop the ideas and eventually the helicopter industry was born, the final accolade on the road to development going to the German Focke-Wulf company in 1936.

Helicopters were used by the German forces in World War II to a small degree, and in the USA Igor Sikorsky was developing his response. Sikorsky went on to become a famous name in helicopters; but simultaneously Arthur Young, working for the Bell Aircraft Corporation, was busy on his designs.

The Bell helicopters went on to become the main force in the industry as well as the first helicopters to be granted a passenger-carrying licence in the USA. Helicopters have since gone on to prove their worth in wars, where they can land in difficult terrain where a conventional fixed-wing aircraft could not land; and, of course, they can also hover at low altitudes, a factor that has made them vital in air-sea rescues, for example. Police and ambulance forces now use them worldwide for this type of work. The oil production industry has also made extensive use of helicopters to ferry personnel and supplies to offshore oil rigs, for example.

A helicopter has four main flight controls: the cyclic, the collective, the anti-torque pedals, and the throttle. The cyclic control is usually located between the pilot's legs and is similar to a joystick and this changes the pitch of the rotor blades cyclically. The control tilts the rotors in a particular direction, allowing the helicopter to move in a particular direction. If the pilot pushes the cyclic stick forward, the rotor disk tilts forward, and produces a thrust in the forward direction. If the pilot pushes the cyclic to the side, the rotor disk tilts to that side and produces thrust in that direction, causing the helicopter to hover sideways.

The collective pitch control or collective is located on the left side of the pilot's seat (in helicopters pilots sit on the right, unlike fixed-wing aircraft where the main control is on the left) with a friction control to prevent inadvertent movement.

The collective changes the pitch angle of all the main rotor blades collectively and independently of their position. Therefore, if a collective input is made, all the blades change equally, and the result is the helicopter increasing or decreasing in altitude. The anti-torque pedals are located in the same position as the rudder pedals in a fixed-wing aircraft, and control the direction in which the nose of the aircraft is pointed. Application of the pedal in a given direction changes the pitch of the tail rotor blades, increasing or reducing the thrust produced by the tail rotor and causing the nose to yaw in the direction of the applied pedal. The pedals mechanically change the pitch of the tail rotor altering the amount of thrust produced.

Helicopter rotors are designed to operate at a specific RPM. The throttle controls the power produced by the engine, which is connected to the rotor by a transmission. The purpose of the throttle is to maintain enough engine power to keep the rotor RPM within allowable limits in order to keep the rotor producing enough lift for flight. In single-engine helicopters, the throttle control is a motorcycle-style twist grip mounted on the collective control, while dual-engine helicopters have a power lever for each engine.