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.
Plain English
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.
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.