Definition
An autopilot or flight director operating state in which the system continuously follows a selected reference, such as a navigation course, glideslope, heading, or altitude, by making ongoing small corrections to keep the airplane aligned with that reference.
Plain English
The mode where the autopilot or flight director is actively staying on a chosen path or value, making constant small adjustments to hold it.
Context Anchor
You see this term when using a flight director or autopilot to follow a selected course, route, or approach path.
Derivation
From the verb 'track,' meaning to follow a path. In aviation, 'tracking' describes the airplane staying on a defined line or reference, so 'tracking mode' is the system state in which it actively does that work for the pilot.
Why Pilots Care
It reduces pilot workload and keeps the aircraft on the intended route or approach centerline without constant manual heading corrections, especially important in crosswind conditions.
Analogy
Like a car’s lane-centering system that keeps the vehicle in the middle of its lane by constantly steering, instead of just holding the steering wheel straight and letting the wind or road push the car sideways.
Intuition Check
Tracking does not mean the system is merely showing or watching the airplane’s position. Here, it means the system is actively guiding the airplane to follow a selected path.
Example Sentence 1
Once the localizer was captured, the autopilot transitioned into tracking mode and held the inbound course to the runway.
Example Sentence 2
Once the localizer was captured, the flight director switched to tracking mode and kept the airplane aligned with the runway centerline.