Definition
A ground-based radio navigation aid that transmits VHF signals allowing a suitably equipped aircraft to determine its bearing to or from the station along any of 360 selectable courses, called radials. The pilot tunes the station's frequency, identifies it by its Morse code identifier, and uses the cockpit indicator to fly toward, away from, or along a specific radial.
Plain English
A radio beacon on the ground that lets a pilot find their direction to or from it. The pilot picks one of 360 invisible lines radiating out from the station and uses the cockpit instrument to follow it.
Context Anchor
Seen on instrument charts, navigation radios, and instrument approach procedures, including procedures used to guide a helicopter toward an area near a VFR heliport.
Derivation
VHF refers to the radio band the station broadcasts on. Omni-directional comes from Latin omnis, meaning all, combined with directional — the station sends usable signals in every direction at once, so a pilot anywhere around it can use it. Range here means a navigation aid that gives bearing information, not distance.
Why Pilots Care
Provides reliable directional guidance that keeps the helicopter on the intended track until visual references are acquired.
Grounding Statement
Picture a ground radio station sending direction information outward in every direction, and the aircraft equipment using that signal to help the pilot stay on the intended path.
Intuition Check
Do not read range here as distance. A basic VOR gives direction information relative to the station; distance requires another source, such as distance-measuring equipment or GPS.
Example Sentence 1
After passing the final approach fix, the pilot tracked inbound on the 270 radial of the VOR to the missed approach point.
Example Sentence 2
Once the VOR indicated the helicopter was on the inbound radial, the crew began the descent to the heliport.