autopilot
n. C / Un. a system that steers a plane or ship without a human pilot. You can also use it to describe doing something without thinking because you have done it many times before.
n. a device or system used to control the path of a vehicle without constant manual intervention. Often used metaphorically to describe a state of performing tasks automatically or without conscious thought.
The pilot turned on the autopilot once the plane reached a safe altitude.
After working the same night shift for three years, he often found himself driving home on autopilot.
Modern aviation relies heavily on sophisticated autopilot systems to maintain precise headings and altitudes, though pilots must remain vigilant to intervene during unexpected turbulence or system failures.
From auto- + pilot.
Commonly used in the prepositional phrase 'on autopilot' when referring to habitual or mindless behavior.