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A quadcopter, also called quadrocopter, or quadrotor is a type of helicopter or multicopter that has four Helicopter rotor.
Although quadrotor helicopters and have long been flown experimentally, the configuration remained a curiosity until the arrival of the modern unmanned aerial vehicle or drone. The small size and low inertia of drones allows use of a particularly simple flight control system, which has greatly increased the practicality of the small quadrotor in this application.
Quadcopters generally have two rotors spinning clockwise (CW) and two counterclockwise (CCW). Flight control is provided by independent variation of the speed and hence lift and torque of each rotor. Pitch and roll are controlled by varying the net centre of thrust, with yaw controlled by varying the net torque.
Unlike conventional helicopters, quadcopters do not usually have cyclic pitch control, in which the angle of the blades varies dynamically as they turn around the rotor hub. In the early days of flight, quadcopters (then referred to either as quadrotors or simply as helicopters) were seen as a possible solution to some of the persistent problems in vertical flight. Torque-induced control issues (as well as efficiency issues originating from the tail rotor, which generates no useful lift) can be eliminated by counter-rotation, and the relatively short blades are much easier to construct. A number of manned designs appeared in the 1920s and 1930s. These vehicles were among the first successful heavier-than-air VTOL vehicles. However, early prototypes suffered from poor performance, and latter prototypes required too much pilot work load, due to poor stability augmentation and limited control authority.
Alternative power sources like hydrogen fuel cells and hybrid gas-electric generators have been used to dramatically extend endurance because of the increased energy density of both hydrogen and gasoline, respectively.McNabb, Miriam (February 2018). US Manufacturer Harris Aerial Launches New Hybrid Gas Electric Drone. Dronelife
The previous Guinness record was was by Samuele Gobbi on 28 February 2025 in Switzerland. and before that it was set by Luke and Mike Bell on 21 April 2024 in South Africa.
Etienne Oehmichen experimented with rotorcraft designs in the 1920s. Among the designs he tried was the Oehmichen No. 2, which employed four two-blade rotors and eight propellers, all driven by a single engine. The angle of the rotor blades could be varied by warping. Five of the propellers, spinning in the horizontal plane, stabilized the machine laterally. Another propeller was mounted at the nose for steering. The remaining pair of propellers functioned as its forward propulsion. The aircraft exhibited a considerable degree of stability and increase in control-accuracy for its time, and made over a thousand test flights during the middle 1920s. By 1923 it was able to remain airborne for several minutes at a time, and on April 14, 1924, it established the first-ever FAI distance record for helicopters of . It demonstrated the ability to complete a circular course "A Successful French Helicopter" Flight 24 January 1924 p47 and later, it completed the first closed-circuit flight by a rotorcraft.
Dr. George de Bothezat and Ivan Jerome developed the de Bothezat helicopter, with six-bladed rotors at the end of an X-shaped structure. Two small propellers with variable pitch were used for thrust and yaw control. The vehicle used collective pitch control. Built by the United States Army Air Service, it made its first flight in October 1922. About 100 flights were made by the end of 1923. The highest it ever reached was about . Although demonstrating feasibility, it was underpowered, unresponsive, mechanically complex and susceptible to reliability problems. Pilot workload was too high during hover to attempt lateral motion.
The Gloster Crop Sprayer project of 1960 was an early example of a quadcopter drone. To be powered by a 105 hp Potez 4E air-cooled flat four-cylinder engine, its 20 gal payload was discharged through a 22 ft spray boom. Two operators carried homing beacons at opposite ends of the spray run, so that the quadcopter would always home in on a beacon and not overshoot. However, despite the much simplified design and operational requirements compared to a piloted machine, the parent company board refused to develop it and it remained a paper project.James, Derek N.; Gloster Aircraft Since 1917, Putnam, 1971, p.413.
The Curtiss-Wright VZ-7 of 1958 was a VTOL aircraft designed by Curtiss-Wright in competition for the U.S. Army Transport and Research Command "flying jeep". The VZ-7 was controlled by changing the thrust of each of the four ducted fan rotors.
The Piasecki PA-97 was a proposal for a large hybrid aircraft in which four helicopter fuselages were combined with a lighter-than-air airship in the 1980s.
Airbus is developing a battery-powered quadcopter to act as an urban air taxi, at first with a pilot but potentially autonomous in the future.
While small toy remote-controlled quadcopters were produced in Japan already in the early 1990s, the first one with a camera to be produced in significant quantities (Draganflyer Stabilized Aerial Video System, retronym Draganflyer I, by Canadian start-up Draganfly) was not designed until 1999.
Around 2005 to 2010, advances in electronics allowed the production of cheap lightweight flight controllers, (IMU), global positioning system and cameras. This resulted in the quadcopter configuration becoming popular for small unmanned aerial vehicles. With their small size and maneuverability, these quadcopters can be flown indoors as well as outdoors.
For small drones, quadcopters are cheaper and more durable than conventional helicopters due to their mechanical simplicity. Their smaller blades are also advantageous because they possess less kinetic energy, reducing their ability to cause damage. For small-scale quadcopters, this makes the vehicles safer for close interaction. It is also possible to fit quadcopters with guards that enclose the rotors, further reducing the potential for damage. However, as size increases, fixed propeller quadcopters develop disadvantages relative to conventional helicopters. Increasing blade size increases their momentum. This means that changes in blade speed take longer, which negatively impacts control. Helicopters do not experience this problem as increasing the size of the rotor disk does not significantly impact the ability to control blade pitch.
Due to their ease of construction and control, quadcopters are popular as amateur model aircraft projects.
Quadcopter drone crime is also occurring in Europe. In August 2021, a police officer in the Czech Republic seized a quadcopter that was transporting a sachet of methamphetamine.
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