Defense Glossary

A quadrotor, commonly called a quadcopter, is a four-rotor multicopter that achieves vertical takeoff and landing, stable hovering, and highly responsive maneuvering by precisely varying the speed of each propeller. Its simplified mechanical design, which eliminates traditional helicopter swashplates, makes it widely used for surveillance, logistics, and recreational drones, with flight control achieved through differential motor speeds and counter-rotating rotors that balance torque while governing altitude, pitch, roll, and yaw.