> Most people do not know the technical details of airplane autopilot systems, because they are not technical nor are they pilots. Colloquially, autopilot means

> Most people do not know the technical details of airplane autopilot systems, because they are not technical nor are they pilots. Colloquially, autopilot means fully autonomous to most people. That's not how they work or are used in aviation: 1) The pilot in command is solely responsible for the flight, not a device. That's why there's 2 pilots on airline flights, and will be for the forseeable future (ie. decades.) 2) Autopilots are either basic levellers (like automotive cruise control systems), or FMS (computer systems.) In either case, a pilot configures them, and is likely to deactivate or re-program them during flight. There's no confusion who is responsible though - solely the pilot in command. 3) The pilot is not there "for legal reasons" - he's there as the airman responsible and in control of the trip. 4) An airline might have minimum equipment lists (MELs) that require a functioning autopilot for revenue flights, but it depends on the aircraft model. (Because airliners are complex machines, it's not required to have every single piece of equipment working for each flight.) Source: commercially-rated airplane pilot.