What does RVR stand for in aviation terms?

RVR stands for Runway Visual Range, which is a critical measure in aviation that indicates the distance a pilot can see along the runway. This measurement is particularly important during low visibility conditions, such as fog or heavy rain, as it directly impacts the ability to take off or land safely.

Runway Visual Range is typically determined by taking readings from transmissometers located at the runway to assess the visibility over the length of the runway. RVR is essential for pilots and air traffic controllers because it helps in making informed decisions regarding aircraft operations in varying weather conditions, ensuring safety during critical phases of flight.

In contrast, the other options refer to concepts that do not exist or are not standard terminology in aviation. For instance, Required Vertical Radius and Runway Velocity Report lack established definitions in the context of aviation operations, and while a Real-time VFR Report might suggest reporting on Visual Flight Rules, it does not specifically correspond to any recognized aviation standard. Thus, the clarity and established usage of Runway Visual Range affirm its correctness in this context.