Definition
The pilot-operated control on a VOR receiver used to select any one of the 360 magnetic courses (radials) to or from a VOR station. Rotating the OBS turns the course arrow on the VOR indicator and tells the receiver which radial the pilot wants to fly or check. The course deviation indicator (CDI) then shows whether the aircraft is left of, right of, or on that selected course.
Plain English
A knob on the VOR instrument that lets the pilot pick which course line, out of all 360 directions around the station, they want to fly along or measure their position from.
Context Anchor
Seen when using a VOR indicator, especially during a VOR equipment check at a marked ground checkpoint or published airborne checkpoint.
Derivation
Omni- comes from Latin omnis, meaning ‘all.’ Bearing is the direction from one point to another. Select means to choose. So omnibearing select literally means ‘choose any direction’ — fitting, since the knob lets the pilot pick any of the 360 possible courses around the VOR.
Why Pilots Care
It lets the pilot precisely align with a chosen VOR radial for accurate navigation and instrument procedure compliance.
Analogy
Think of the OBS like setting a number on a dial before checking an instrument. If you set the wrong number, the comparison will not tell you whether the instrument is actually accurate.
Intuition Check
Turning the OBS does not turn the airplane and does not change the VOR signal. It only changes the course selected on the cockpit instrument.
Example Sentence 1
After tuning the VOR frequency, the pilot rotated the OBS to 270 to track the radial inbound to the station.
Example Sentence 2
She turned the OBS knob until the course deviation indicator centered on the selected bearing.