Definition
A combined airborne navigation receiver that processes signals from VHF Omnidirectional Range (VOR) ground stations and from Localizer transmitters, which are the lateral guidance component of an Instrument Landing System (ILS). Both signal types are broadcast in the very high frequency (VHF) band between 108.0 and 117.95 MHz, allowing a single receiver to handle en route VOR navigation and final approach localizer guidance.
Plain English
One radio in the cockpit that can do two navigation jobs: tell you where you are relative to a VOR station along your route, and guide you left or right onto the runway centerline during an instrument landing approach.
Context Anchor
Seen on older or conventional navigation/communication radio panels, especially where one unit is labeled for VOR and localizer navigation use.
Derivation
VHF stands for very high frequency, the radio band used. 'Omni' comes from Latin omnis meaning 'all,' because a VOR sends signals in all directions, letting an aircraft navigate from any bearing. 'Localizer' refers to the signal that locates the runway centerline for approach.
Why Pilots Care
One receiver covering both VOR and localizer signals saves panel space and weight, and it means the same tuning and display equipment is used for en route navigation and for the lateral part of an ILS approach.
Intuition Check
“Omni” does not mean the radio receives every possible signal; here it refers to navigation course information available in all directions from a VOR station. “Localizer” does not give full runway guidance by itself; it gives left-right alignment with the runway path.
Example Sentence 1
She tuned the VHF Omni/Localizer to 110.30 to pick up the ILS for runway 27.
Example Sentence 2
The VHF Omni/Localizer receiver fed both VOR and localizer information to the same course deviation indicator.