Definition
An automated system that controls engine thrust by moving the throttle levers to maintain a commanded airspeed, Mach number, or thrust setting selected by the pilot or driven by the flight management system.
Plain English
A system that pushes and pulls the throttles for you to keep the engines at the right power setting, so you don't have to do it by hand.
Context Anchor
Seen in FMS and automated flight discussions, especially when managing speed, climbs, descents, and approaches in aircraft equipped with automatic engine-power control.
Derivation
Auto comes from Greek 'autos' meaning 'self.' A throttle is the lever that controls engine power. Together, 'auto-throttle' means a self-acting throttle — one that moves on its own to manage thrust.
Why Pilots Care
Reduces workload and improves speed precision, which supports fuel efficiency and stable approaches.
Analogy
Like cruise control in a car: you set the speed you want, and the system manages the throttle to hold it.
Intuition Check
Auto-throttles do not fly the airplane by themselves, and they do not remove the need to monitor power. They control engine power; the pilot must still confirm the selected mode, target speed or power, and actual engine response.
Example Sentence 1
After leveling off in cruise, the crew engaged the auto-throttles to hold the selected airspeed.
Example Sentence 2
With the auto-throttles active, the FMS could reduce thrust smoothly as the aircraft leveled off at the assigned altitude.