The autopilot system relies on a series of sensors around the aircraft that pick up information like speed, altitude and turbulence. That data are ingested into the computer, which then makes the necessary changes. Basically, it can do almost everything a pilot can do.

Are planes always on autopilot?

Not all of the passenger aircraft flying today have an autopilot system. Older and smaller general aviation aircraft especially are still hand-flown, and even small airliners with fewer than twenty seats may also be without an autopilot as they are used on short-duration flights with two pilots.

What does autopilot actually do?

An autopilot is a software or tool that can only manage the aircraft under certain conditions using the vehicle's hydraulic, mechanical and electronic systems. This system, which can follow the flight plan, can stabilize speed and height as well as the location of the front of the aircraft (heading).