Quadcopter

A quadcopter, also called a quadrocopter, or quadrotor is a type of helicopter or multicopter that has four rotors. These small flying machines are very interesting because they can move up, down, and in many directions easily.

Although quadrotor helicopters and convertiplanes have been tested for a long time, they were just curious ideas until modern unmanned aerial vehicle or drone technology arrived. The small size and low inertia of drones makes it easy to control their flight, which has made small quadrotors very useful, especially for things like delivering packages or taking pictures from the air.

Design principles

Each rotor helps the quadcopter fly by creating lift and turning force, as well as pushing air back to slow it down. Quadcopters usually have two rotors turning one way and two turning the opposite way. This helps control how the quadcopter moves up and down, and turns.

Unlike regular helicopters, quadcopters do not change the angle of their blades while spinning. In the early days, people thought quadcopters might solve some problems with flying straight up and down. Some designs from the 1920s and 1930s were among the first to do this, but they were hard to control and not very good.

When all four rotors spin at the same speed, one way and the other the opposite way, the quadcopter does not twist. This means it does not need a tail rotor like regular helicopters. Turning the quadcopter is done by changing how hard the rotors spin.

All quadcopters follow the same air rules as other flying machines with rotors.

The main parts of a quadcopter are its body, four rotors, and motors. The motors and propellers are placed the same distance apart for the best performance.

In some designs, each arm has two motors turning in opposite directions to make the quadcopter stronger and more stable but lighter.

Operations

Autonomous flight

The quadcopter is easy to program for flying on its own. This has led to fun experiments where many quadcopters work together, using simple sensors to notice nearby drones.

Records

Endurance

A battery-powered quadcopter once flew for 2 hours, 31 minutes, and 30 seconds. This record was set in 2016 by Ferdinand Kickinger from Germany. He used special batteries and made the quadcopter very light to help it stay in the air longer. Other ways to make quadcopters fly longer include using hydrogen fuel cells or hybrid gas-electric generators.

Speed

The fastest quadcopter ever flew at a speed of 657.59 km/h (408.61 mph). This record was set by Luke and Mike Bell in Cape Town, South Africa on December 11, 2025. To set the record, they measured the average speed of two 100-meter runs in opposite directions to balance out any wind.

History

Pioneers

The first heavier-than-air aerodyne to take off vertically was a four-rotor helicopter designed by Louis Breguet. It was tested only in short flights and reached only a few feet in height. In 1908 it was reported to have flown several times, though details are limited.

Etienne Oehmichen experimented with rotorcraft designs in the 1920s. One of his designs, the Oehmichen No. 2, used four two-blade rotors and eight propellers, all powered by one engine. This aircraft showed good stability and control for its time, making over a thousand test flights. By 1923 it could stay in the air for several minutes, and in 1924 it set the first distance record for helicopters by flying 360 meters.

Dr. George de Bothezat and Ivan Jerome developed the de Bothezat helicopter, which had six-bladed rotors on an X-shaped frame. This helicopter made its first flight in October 1922 and about 100 flights followed. It reached a height of about 5 meters. Though it showed that the design was possible, it had problems with power and control.

Postwar era

The Convertawings Model A Quadrotor was meant to be the first of many larger helicopters. It had two engines powering four rotors and could fly forward successfully starting in 1956. However, there were no orders for it, so the project ended. Convertawings planned a larger model that could carry heavy loads over long distances.

The Gloster Crop Sprayer project in 1960 was an early idea for a quadcopter drone. It would use a small engine and carry crop spray. Operators with beacons would guide it to avoid going too far. But the company decided not to build it, so it stayed only on paper.

The Curtiss-Wright VZ-7 from 1958 was a special aircraft for the U.S. Army. It could take off and land vertically by changing the power of its four fan rotors.

The Piasecki PA-97 was a plan in the 1980s to combine four helicopter bodies with an airship.

Recent developments

The Bell Boeing Quad TiltRotor idea combines a quadcopter with a tilt rotor to make a large military transport.

Airbus is working on a battery-powered quadcopter to use as a city air taxi, which might fly on its own in the future.

Drones

In the early 2000s, the four-rotor design became popular for small unmanned aerial vehicles or drones. This design is simple but reliable and easy to control. Research continues to improve drones so they can work together and explore new places.

Although small remote-controlled quadcopters were made in Japan in the early 1990s, the first one with a camera made in large numbers was created in 1999.

From about 2005 to 2010, better electronics made it possible to produce cheap, light quadcopters with cameras. Their small size and ability to turn quickly let them fly both inside and outside.

For small drones, quadcopters are cheaper and safer than helicopters because they have fewer moving parts. Their small blades also cause less damage if they hit something. Guards can be added around the blades to make them even safer. But as quadcopters grow larger, they can become harder to control quickly compared to helicopters.

Because they are easy to build and control, quadcopters are popular projects for hobbyists.

Military use

Small drones began being used by Ukrainian and Russian forces during the conflict in Ukraine starting in 2022. They were first used to gather information from the air and later as small bombers.

Main article: Drone warfare § Russian invasion of Ukraine