Definition
Runway Visual Range is the maximum distance, measured in feet, at which a pilot at the approach end of a runway can see the runway surface markings, the runway edge lights, or the centerline lights. RVR is determined by transmissometers or forward-scatter sensors positioned alongside the runway and reported automatically rather than estimated by an observer.
Plain English
It is a measurement of how far down a runway a pilot can actually see at the moment of landing or takeoff. The number comes from instruments next to the runway, not from a person looking out a window.
Context Anchor
Pilots encounter RVR in airport weather reports, control tower information, and low-visibility takeoff or landing requirements.
Derivation
The phrase 'visual range' was adopted because the value represents the distance a pilot can see along the runway, not the general weather visibility reported for the airport as a whole. The word 'range' here means 'reach of sight,' the same sense used in 'visual range' for ships at sea.
Why Pilots Care
RVR determines whether visibility meets the minimums required for a particular instrument approach procedure, directly affecting go/no-go decisions in fog or haze.
Intuition Check
RVR is not a general guess at how clear the whole airport looks. It is a runway-specific measured distance, usually reported in feet, for seeing markings or lights along that runway.
Example Sentence 1
Tower reported RVR 2400 for Runway 27, which was above the minimum required for the ILS approach.
Example Sentence 2
Controllers provide updated RVR readings to pilots on final approach when visibility is changing rapidly.