AVIATION ROUTING WEATHER REPORT (METAR)

Runway Visual Range Group
(RDRDR/VRVRVR VRFT
or
RDRDR/VnVnVn VnVVxVxVxVxFT)

Index

Definitions and Standards for Observing and Reporting Runway Visual Range
Summary of RVR Observing and Reporting Standards
Coding and Interpreting Coded Runway Visual Range Groups

Definitions and Standards for observing and reporting Runway Visual Range

Runway Visual Range (RVR)
The runway visual range is the maximum distance at which the runway, or the specified lights or markers delineating it, can be seen from a position above a specified point on its centerline. This value is normally determined by visibility sensors located alongside and higher than the center line of the runway. RVR is calculated from visibility, ambient light level, and runway light intensity. It is common practice to use a transmissometer or forward scatter meter as the RVR visibility sensor. A transmissometer measures the transmittance of the atmosphere over a baseline distance while a forward scatter meter measures the extinction coefficient of the atmosphere. RVR is then derived from equations that also account for ambient light (background luminance) and runway light intensity based on the expected detection sensitivity of the pilot's eye.

Observing Positions
The location of the RVR visibility sensor should be within 500 feet of the runway centerline and within 1,000 feet of the designated runway threshold.

Day-Night Observations for Transmissometers
The day scale shall be used in the evening until low intensity lights on or near the airport complex are clearly visible. The night scale shall be used in the morning until these lights begin to fade. Alternately, a day-night switch may be used to determine which scale should be used.

Multiple Runway Visual Range Sensors
At automated stations where it is applicable, RVR values for as many as four designated runways can be reported for long-line dissemination. At manual stations, only RVR for the designated runway shall be reported.

Units of Measure
RVR is measured in increments of 100 feet up to 1,000 feet, increments of 200 feet from 1,000 feet to 3,000 feet, and increments of 500 feet above 3,000 feet to 6,000 feet.

Runway Visual Range Based on a Transmissometer
Ten-minute extreme values (highest and lowest) of transmittance shall be reported. Manually reported RVR shall be based on light setting 5 for either day or night time conditions, regardless of the light setting actually in use. One RVR value shall be reported if the ten-minute high and low value are the same.

Table A-5 summarizes the runway visual range observing and reporting standards.

Table A-5 Summary of RVR Observing and Reporting Standards
RVR Observing and Reporting Standard
Number of RVRs Up to 4a
RVR Light Setting 5 for transmissometer systems
When Reported When visibility less than or
equal to 1 statute mile
AND/OR
RVR less than or equal to 6,000 feet
a. Manual Observations shall contain only one RVR

Coding and Decoding the Runway Visual Range Group

  1. RVR shall be coded in the format, RDRDR/ VRVRVRVRFT, where R indicates that the runway number follows, DRDR is the runway number (an additional DR may be used for runway approach directions, such as R for right, L for left, and C for center), VRVR VRVR is the constant reportable value, and FT indicates that units of measurement are feet. A solidus "/" without spaces separates the runway number from the constant reportable value. For example, an RVR value for runway 01L of 800 feet would be coded

    R01L/0800FT.

  2. RVR that is varying shall be coded in the format, RDRDR/VnVnVn VnVVxVxVxVxFT, where R indicates that the runway number follows, DRDR is the runway number (an additional DR may be used for runway approach directions, such as R for right, L for left, and C for center), VnVnVnVn is the lowest reportable value in feet, V separates lowest and highest visual range values, VxVxVxVx is the highest reportable value, and FT indicates that units of measurement are feet. A solidus "/" without spaces separates the runway number from the reportable values. For example, the 10-minute RVR for runway 01L varying between 600 and 1,000 feet would be coded

    R01L/0600V1000FT.

  3. The values shall be based on light setting 5 at manual stations regardless of the light setting actually in use.

  4. RVR values shall be coded in increments of 100 feet up to 1,000 feet, increments of 200 feet from 1,000 feet to 3,000 feet, and increments of 500 feet from 3,000 feet to 6,000 feet.

  5. Manual RVR shall not be reported below 600 feet. For automated stations, RVR may be reported from up to four designated runways.

  6. If the RVR is less than its lowest reportable value, the VR VRVRVR or VnVnVnVn groups shall be preceded by M. If the RVR is greater than its highest reportable value, the VRVRVR VR or VxVxVxVx groups shall be preceded by a P. For example, an RVR for runway 01L of less than 600 feet will be coded

    R01L/M0600FT.

    An RVR for runway 27 of greater than 6,000 feet will be coded

    R27/P6000FT.

Note: ICAO standards indicate runway visual range is reported in meters when visibility is less than 1500 meters. The designator i in the ICAO format is the RVR tendency, either a U (for increasing) or a D (for decreasing) if during the 10 minutes preceding the observation the runway visual range showed a tendency to increase or decrease. If no change occurred, it is omitted.

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