Definition
A ground-based radio navigation aid that transmits signals in the very high frequency (VHF) band, allowing aircraft equipped with a VOR receiver to determine their bearing to or from the station along any one of 360 selectable courses (radials).
Plain English
A ground radio station that lets a pilot tell which direction they are from it. The pilot picks a line out from the station and the cockpit instrument shows whether they are left or right of that line.
Context Anchor
Seen on instrument approach charts, navigation charts, and aircraft navigation radios when a procedure or route is based on a VOR station.
Derivation
‘Omni-directional’ comes from the Latin ‘omnis’ meaning ‘all’ and ‘directional’ from ‘directio’ meaning ‘a setting straight.’ Together it means ‘in all directions’ — the station broadcasts usable signals in every direction from it, so a pilot can fly toward or away from it on any course they choose.
Why Pilots Care
Supplies reliable directional guidance when visual references are limited or unavailable.
Analogy
Think of a lighthouse that sends out 360 invisible spokes, one for each degree of the compass. The cockpit instrument tells the pilot which spoke they are sitting on and whether they are drifting off it.
Intuition Check
Do not read range here as “how far away it reaches.” In this term, range means a radio navigation system that gives direction information from a ground station.
Example Sentence 1
After takeoff, the pilot tuned the VOR and intercepted the 270 radial outbound to join the airway.
Example Sentence 2
During the helicopter approach the crew cross-checked their position against the very high frequency omni-directional range signal.