An helicopter is a vertically launching and landing aircraft that transmits engine power to one or more rotors for boost and propulsion. These operate as rotating wings or wings, which is why helicopters count to the rotor blades.

The word helicopter, or heli for short, is composed of ancient Greek ἕλιξ hélix “winding, spiral” and πτερόν pterón “wing” (rotary wing).

Helicopters does not include mixed aircraft with rotor blades, for example hybrids from rotary and fixed-wing aircraft or aircraft without a main main rotor such as a helicopter.

1487 Leonardo da Vinci had already sketched a helicopter around 1487-1490 in his so-called “Paris manuscripts,” but only in the twentieth century did the technical realization of this idea succeed. Pioneers of the helicopter development were, among others, Jakob Degen, Étienne Œhmichen, Raúl Pateras Pescara, Oszkár Asbóth, Juan de la Cierva, Engelbert Zaschka, Louis Charles Breguet, Alberto Santos Dumont, Henrich Focke and Igor Sikorski.

1907 Paul Cornu lifted his ground with his 260 kg flying bike for 20 seconds from the ground; It was the first documented free manned vertical flight. He used tandem rotors powered by a 24 hp V8 engine.

1910 Boris Nikolayevich Yevyev solved some theoretical and constructive problems of stability and drive and developed the swash plate.

1913 The Dresden engineer Otto Baumgärtel constructed a vertical starter, which was able to carry out forward movements without shifting the center of gravity without special propellers.

Towards the end of the First World War, the designers Stephan Petróczy of Petrócz, Theodore of Kármán and Wilhelm Zurovec commissioned the k.u.k. Army successful flight tests with the PKZ-1 and PKZ-2 screw-type fasteners named after them. By such vertically ascending aircrafts, the hitherto customary balloon for enemy observation should be replaced. The PKZ-2 reached an airport of about 50 m, which was a record at that time. In a demonstration flight on 10 June 1918 in Fischamend, the unit crashed. The ending war prevented further development.

1922 On November 11, Étienne Œhmichen launched his first Noct.2, the first documented and reliably flying man-carrying vertical starter, a quadrocopter.

1923 In the development of his Autogiro, Juan de la Cierva (Spain), in 1923, obtained important solutions for stabilizing the rotors of a rotary wing, such as the striking joints.

1924 The Pescara No. 2, developed by Raúl Pateras Pescara, earns world record for rotorcraft by doubling, using a cyclic blade adjustment for the first time to use the main rotor for propulsion.

1933 Louis Charles Breguet and René Dorand built the first long-term stable flying helicopter with the Gyroplane Laboratoire. He had coaxial rotors and from June 1935 held all international records for helicopters.

1936 The Focke-Wulf Fw 61, which used two laterally arranged rotors, was able to break a series of world records in helicopters during the air parade in June 1936. It was also the first practical helicopter.

1941 The German Focke-Achgelis Fa 223 remains the first series-built helicopter, also with two laterally arranged rotors. This was followed by the Flettner Fl 282, also with twin rotor, in 1943.

1944 The Sikorsky R-4 “Hoverfly” starts its service. It uses, like its predecessor, Sikorsky VS-300,  a single rotor together with a tail rotor.

1946 The Bell 47 Bell Aircraft Corporation, a light two- or three-seat helicopter, became the first civilian helicopter to be licensed in the United States. Its variants were to be found worldwide until the 1980s and beyond.

1955 The French company Sud Aviation equipped its Alouette II helicopter with a 250 kW Turbomeca Artouste shaft turbine, thereby building the first helicopter with gas turbine engine, which is now used by almost all commercial manufacturers. Only Robinson Helicopter (Robinson R22 and Robinson R44), Brantly (Brantly B-2 and Brantly 305) and Sikorsky (Swiss 300C) still produce helicopters with piston engines.

1956 The helicopter family, the Bell 204 – military Bell UH-1, with its 16,000 copies to date, was launched on 22 October 1956 for its maiden flight.

1967 The German Bölkow Bo 105 was equipped as the first helicopter with an articulated rotor head together with GFK rotor blades, which had been used for the first time in the Kamov Ka-26. The Eurocopter EC 135 as the current successor uses a further developed form, the so-called articulated and bearingless rotor head. There, the bearings for the blade angle adjustment were also replaced by a drilled control element consisting of glass fiber reinforced plastic with control box.

1968 began with the Soviet Mil Mi-12 the largest ever built helicopter. It has rotors arranged side by side, a maximum take-off weight of 105 t with a maximum payload of 40 t and 196 passenger places. After three prototypes, which produced a series of records, production was discontinued.

1977 the first flight of the largest series-built helicopter took place, the Mil Mi-26, which is still produced and used today.

1983 A Boeing-Sikorsky RAH-66 Comanche was developed from 1983 with a new camouflage technology, but the production was halted shortly before reaching the deployment stage in 2004 due to escalating costs.

1984 For the first time, the Sikorsky X-wing flew, whose rotor is stopped and determined during forward flight, and then serves as an additional support surface. As with other VTOL concepts, better flight performance is to be achieved in comparison to pure rotor blades. However, a prototype remained.

2008 The Sikorsky X2 demonstrated the suitability of the latest optimized coaxial rotor in combination with a thrust propeller – the principle of earlier helicopters. Two years later he reached the development goal with 250 knots of True Airspeed (463 km/h), thus surpassing the previous speed record by 15%. Also other manufacturers tested similar new high-speed patterns, like the Eurocopter the X³ and Kamov Ka-92.

2011 the world’s first manned flight with a purely electrically powered helicopter took place with the Volocopter.