Definition
The distance ahead of a course change at which a pilot or flight management system must begin a turn so that the aircraft rolls out precisely on the new course. It depends on groundspeed, bank angle, and the angle of course change, and is calculated to account for the curved path the aircraft follows during the turn rather than turning directly over the waypoint.
Plain English
How far before a turning point you need to start the turn so you end up lined up correctly on the next leg, instead of overshooting it.
Context Anchor
Seen in GPS or flight management system route planning, especially when the system leads a turn before the next route point.
Derivation
From 'anticipation' (Latin anticipare, 'to take before') -- the turn is begun before reaching the waypoint, not at it. The word captures the key idea: act early so the aircraft arrives on course rather than passing the point and then correcting.
Why Pilots Care
Prevents overshooting course changes, keeps the aircraft on protected airspace, and maintains accurate arrival timing on approaches and arrivals.
Analogy
It is like starting to steer before a bend in the road, instead of waiting until the front of the car is already at the corner.
Intuition Check
Do not read this as the total distance flown during the turn. It means the lead distance before the route point where the turn should begin.
Example Sentence 1
At higher groundspeeds the distance of turn anticipation increases, so the FMS commanded the turn well before the waypoint.
Example Sentence 2
The pilot waited until the GPS showed the distance of turn anticipation before rolling into the standard-rate turn.