Definition
A flight management system feature in which the aircraft automatically adjusts engine thrust to maintain a target airspeed, Mach number, or thrust setting selected by the pilot or commanded by the autopilot or flight management computer.
Plain English
The aircraft moves the throttles by itself to hold the speed or power setting the pilot has chosen, instead of the pilot pushing the levers manually.
Context Anchor
Seen in discussions of LNAV/VNAV equipment and instrument approaches where the aircraft must manage both lateral guidance and a planned vertical path.
Derivation
Auto- comes from the Greek autos, meaning self. Throttle refers to the control that regulates engine power. Together it means the engine power lever operates itself, under system command.
Why Pilots Care
It reduces pilot workload and helps maintain precise speed control during instrument approaches and descents.
Analogy
It is similar to cruise control in a car: the system can adjust power to help hold a target speed, but the driver—or pilot—still remains responsible for monitoring and taking over when needed.
Intuition Check
Auto-throttle does not mean the airplane is flying the whole approach by itself. It only means the system can adjust engine power; the pilot still controls, monitors, and remains responsible for the flight.
Example Sentence 1
With the auto-throttle engaged, the aircraft held the approach speed precisely as it descended toward the runway.
Example Sentence 2
Before accepting an RNP approach clearance, the pilot confirmed the airplane had auto-throttle capability coupled to the flight director.