Runway visual range vs visibility explained: how RVR is measured and reported, why values differ, and which applies to landing minima.
In aviation and real-world flying, visibility describes the general horizontal distance at which objects can be seen and identified, while runway visual range (RVR) estimates how far a pilot on a specific runway's centreline can see its markings or lights. Visibility covers the aerodrome area; RVR is runway-specific and operationally focused.
RVR vs visibility at a glance
The practical distinction is that visibility describes the surrounding weather, whereas RVR describes the visual environment along a particular runway.
| Feature | Visibility | Runway visual range |
|---|---|---|
| Area represented | Broad conditions around the observation point or aerodrome | A specific runway, sometimes divided into touchdown, midpoint and rollout sections |
| Visual target | Suitable objects or lights in the surrounding area | Runway markings, edge lights or centreline lights viewed along the centreline |
| Reported units | Metres, kilometres or statute miles, depending on the reporting system | Metres or feet |
| Main operational use | General weather reporting and procedures whose minima specify visibility | Low-visibility take-off, approach and landing operations |
RVR is not the amount of runway visible from an aircraft on final approach, nor is it the runway length remaining. Its formal concept is the distance over which a pilot positioned on the centreline could see the markings or lights defining that runway.
How are RVR and visibility measured?
Visibility is observed or derived for the aerodrome and is intended to represent general horizontal conditions. Depending on the country and reporting system, a METAR may provide prevailing visibility and may also identify significant directional or minimum visibility.
RVR is normally calculated from calibrated optical sensors beside the runway. The system accounts for atmospheric transmission, background brightness and runway-light intensity, so it is not simply ordinary visibility measured in different units. Airports may have separate sensors near the touchdown zone, midpoint and rollout end.
In a METAR, R27/0600 commonly indicates an RVR of 600 metres for runway 27, while R27L/2400FT reports 2,400 feet for runway 27 Left. Prefixes such as M and P mean below or above the system's reporting limit; some formats also show variable values or increasing, decreasing and steady trends. Our guide to decoding visibility and RVR groups in METARs covers the wider report format.
A missing RVR group does not automatically mean unrestricted visibility. The aerodrome may not provide RVR, the equipment may be unavailable, or conditions may be above the threshold at which RVR is included.
Why can RVR and visibility be different?
RVR and reported visibility can disagree without either report being wrong because they use different locations, visual targets and calculation methods.
- Runway lighting: Bright centreline and edge lights may be detectable through haze or darkness at a greater distance than ordinary objects, producing an RVR higher than general visibility.
- Localised weather: A fog bank, shower or drifting snow over one part of a runway can reduce its RVR while the aerodrome's prevailing visibility remains better.
- Sensor position: Touchdown, midpoint and rollout sensors sample different sections, so one runway can have several substantially different RVR values.
- Background brightness: Daylight, darkness and surrounding light affect the contrast calculation used for RVR.
The lights involved are operational visual references, not decoration. Our explanation of how pilots use runway edge, threshold and centreline lights shows why their intensity and placement matter in poor visibility.
Which value controls an approach or take-off?
The published procedure and applicable operating rules determine whether RVR or visibility is controlling. If a procedure specifies an RVR minimum, pilots cannot normally substitute a more favourable general visibility figure unless their regulations and approved procedures explicitly permit a conversion.
Likewise, converting 600 metres into feet does not turn RVR into meteorological visibility. It only converts the unit. Any authorised equivalence between visibility and RVR must come from the applicable regulatory table or operating approval.
Low-visibility procedures may also specify which runway positions are controlling. The touchdown-zone value is often central to an approach, while midpoint or rollout values may matter for very low visibility or take-off; the precise requirement varies by authority, operation and aircraft approval. Never select whichever sensor gives the best number.
RVR is only the horizontal visual requirement. Decision altitude, decision height or minimum descent altitude remains a separate vertical limit, as explained in our guide to applying approach minima and deciding whether to continue. Lower-category operations generally demand better visual conditions than specially approved CAT II or CAT III operations, but the exact values depend on the procedure and equipment; see the operational distinctions between ILS categories.
How should flight-simulator pilots use RVR?
Use an explicitly reported RVR against an RVR minimum and reported visibility against a visibility minimum. If the weather source supplies only general visibility, do not invent a precise runway-specific RVR from it.
Many consumer simulators render one airport-wide visibility layer rather than modelling every RVR sensor and runway segment independently. Bloom, monitor contrast, runway-light settings and weather-engine behaviour can also make the visual runway appear easier or harder to see than the reported figure suggests. For a procedural simulation, the weather report and charted minimum should govern the decision rather than a visual estimate from the screen.