What does Runway Visual Range (RVR) indicate?

Runway Visual Range (RVR) specifically measures the horizontal distance that a pilot can see down the runway from the approach end. This is crucial for pilots during takeoff and landing phases, especially in low visibility conditions. It provides a standardized measurement that indicates how far ahead the pilot can visually identify the runway environment, including runway markings and lights, which are essential for safe landings and takeoffs.

Understanding RVR is particularly important in aviation because it helps to determine if conditions are suitable for certain operations, such as whether an approach can be made under instrument flight rules (IFR). In lower visibility situations, knowing the RVR allows pilots to assess the safety of the approach and to make informed decisions about whether to proceed or to divert.