What does runway visual range (RVR) indicate?

Runway visual range (RVR) specifically refers to the distance at which a runway or its associated lights can be seen by a pilot from a specific point, typically at the threshold of the runway. It is a critical measurement in aviation as it informs pilots about the visual conditions they can expect during landing and takeoff, ultimately influencing their decisions regarding safety and approach.

RVR is vital, especially in low visibility conditions such as fog or heavy rain, where traditional visibility measurements might not accurately reflect the actual visual information a pilot has. The RVR value is usually determined by sensors or optical devices that measure how far down the runway the pilot can see and is expressed in meters or feet.

The other options describe different visibility or distance concepts that are not specific to the runway context. For instance, the greatest distance visible in a specified sector pertains to general visibility data rather than the specific measurement of runway visibility. Visibility from an observation point might indicate environmental conditions but does not focus on the needs and perspective of a pilot on the runway. The maximum distance into total obscuration deals with how far one can see under complete fog or haze, which does not align with the specific operational importance of RVR. Thus, the choice that encapsulates the essence of runway visual