Plain English Meaning

A system that flies the airplane for you when you set it up correctly. You tell it what heading, altitude, or course to hold, and it moves the controls to keep the airplane doing that — but the pilot still has to monitor it and stays responsible for the flight.

Full Definition

An aircraft system that automatically controls the flight path of an airplane by adjusting the flight controls to hold or capture a selected attitude, heading, altitude, vertical speed, or navigation course. Autopilots range from simple wing-levelers (single-axis) to two-axis that also , and three-axis systems that add . Modern autopilots typically integrate with the aircraft's navigation and systems and require at all times.