Definition
The Runway Visual Range value reported from a sensor located near the approach end of the runway, in the area where landing aircraft first touch down. It is the controlling RVR for most instrument approaches to that runway and is the primary visibility value used to determine whether an approach may be initiated or continued to landing under low-visibility minimums.
Plain English
It is the visibility reading taken at the part of the runway where airplanes are expected to land. Pilots use this number to decide if they have enough visibility to legally fly the approach.
Context Anchor
Seen in instrument procedure discussions, weather reports, approach minimums, and operations specifications that state what visibility is required before beginning or continuing a landing.
Derivation
RVR stands for Runway Visual Range, which is a measured horizontal distance a pilot can expect to see down the runway. 'Touchdown zone' refers to the first 3,000 feet of runway beyond the threshold, where aircraft are intended to land. Combining the two gives a visibility measurement specifically at the spot that matters most for landing.
Why Pilots Care
It directly affects whether a helicopter can continue an instrument approach to a landing or must execute a missed approach in low-visibility conditions.
Intuition Check
Do not read “touchdown zone” as the whole runway. It means the defined landing area near the runway threshold. Do not read RVR as general airport visibility. It is the reported seeing distance along a specific runway area.
Example Sentence 1
Tower reported TDZ RVR 2400, which was above the 1800 minimum for the approach, so the crew continued inbound.
Example Sentence 2
With the reported TDZ RVR below minimums, the helicopter crew initiated the missed approach procedure.