Plain English Meaning
A short line on the controller's radar screen that shows where an aircraft will be in the next minute or two if it keeps flying as it is now.
Full Definition
A line drawn on an air traffic controller's radar display that indicates the projected path of an aircraft over a short period, based on its current heading and groundspeed. The length of the line typically represents how far the aircraft will travel in a set number of minutes, helping the controller anticipate position and separation.
Context Anchor
Used in discussions of air traffic control sectors, where controllers watch aircraft symbols on a display and manage traffic within their assigned area.
Derivation
From Latin 'vector' meaning 'carrier' or 'one who conveys' — in navigation and math, a vector carries both direction and magnitude. The 'line' on the radar carries that same idea: it shows direction (where the aircraft is heading) and magnitude (how far it will go in a given time).
Why Pilots Care
Following the correct vector line prevents deviations from assigned routes and maintains separation from other traffic.
Grounding Statement
Picture an aircraft symbol on a controller’s screen with a small line pointing ahead of it, showing the direction it is currently traveling.
Intuition Check
Do not confuse a vector line with an ATC vector. An ATC vector is an instruction to fly a heading; a vector line is a display aid showing an aircraft’s present or predicted movement.
Example Sentence 1
The controller noticed two vector lines beginning to converge and issued a heading change to maintain separation.
Example Sentence 2
On the sector display, the vector line helped visualize the turn onto the downwind leg.