Definition
A Runway Visual Range value of 150 feet, meaning the horizontal distance a pilot can expect to see down the runway from the approach end is 150 feet. In the context of ILS approach categories, RVR 150 feet is the lowest landing minimum associated with Category IIIc operations, which require specially certified aircraft, crew, and ground equipment. RVR is measured electronically by transmissometers or forward-scatter sensors positioned alongside the runway and is reported in feet (or meters internationally).
Plain English
The pilot can only see about 150 feet ahead down the runway. That is roughly half the length of a football field. At this visibility, landing is only allowed with the most advanced autoland systems and trained crews.
Context Anchor
Seen in ILS approach category tables and low-visibility landing minimums, especially for Category III operations.
Derivation
RVR stands for Runway Visual Range. The term came into use as instrument approaches advanced in the mid-20th century and pilots needed a measurement of visibility taken right at the runway, rather than the general airport visibility reported in a METAR. 'Range' here means viewing distance, not a distance to fly.
Why Pilots Care
Determines whether a pilot may continue an approach to landing or must execute a missed approach in extremely low visibility.
Grounding Statement
Imagine standing on a runway in dense fog and being able to see only halfway to the next runway light before everything disappears into white. That is what RVR 150 feet looks like.
Intuition Check
RVR 150 feet is not the length of the runway and not cloud height. It is the reported distance a pilot can see along the runway surface.
Example Sentence 1
With RVR 150 feet reported on Runway 27L, only Category IIIc-certified aircraft and crews could legally continue the approach to landing.
Example Sentence 2
With reported RVR at 150 feet the crew confirmed rollout guidance was available before continuing the approach.