A little something I put together for our Anchorage controllers. We love our winter season up here. Figured I would share one of those little things you might encounter online.
What is RVR:
Runway Visual Range (RVR) is a term used in aviation meteorology to define the distance over which a pilot of an aircraft on the centreline of the runway can see the runway surface markings delineating the runway or identifying its centre line. RVR is normally expressed in feet or metres. RVR is used as one of the main criteria for minima on instrument approaches, as in most cases a pilot must obtain visual reference of the runway to land an aircraft. The maximum RVR reading is 2,000 metres or 6,500 feet, above which it is not significant and thus does not need to be reported. RVRs are provided in METARs and are transmitted by air traffic controllers to aircraft making approaches to allow pilots to assess whether it is prudent and legal to make an approach.
Originally RVR was measured by a person, either by viewing the runway lights from the top of a vehicle parked on the runway threshold, or by viewing special angled runway lights from a tower at one side of the runway. The number of lights visible could then be converted to a distance to give the RVR. This is known as the human observer method and can still be used as a fall-back. Today most airports use Instrumented Runway Visual Range or IRVR, which is measured by devices called transmissometers which are installed at one side of a runway relatively close to its edge. Normally three are provided, one at each end of the runway and one at the mid-point.
RVR in a METAR:
R07R/2600FT Means Runway Visual Range (RVR). Signifies that the runway visual range for runway 07 Right is 2600 feet. The format is R(XXX) Runway Designator including (L)eft ©enter or ®ight /(XXXX) 4 digit visibility in feet.
Some coding pilots may also see for RVR include:
M Indicates that RVR is less than lowest reportable sensor value (e.g. M0600FT)
P Indicates RVR greater than highest reportable sensor value (e.g. P6000FT).
V Variable If the RVR is variable between 2000 and 4000 feet for runway 6L: (R06L/2000V4000FT). May contain up to four RVR reports.
RVR Phraseology:
Provide RVR/RVV information by stating the runway, the abbreviation RVR/RVV, and the indicated value.
Example: Runway Seven Right RVR Two Thousand Six Hundred.
When there is a requirement to issue an RVR or RVV value and a visibility condition greater or less than the reportable values of the equipment is indicated, state the condition as “MORE THAN” or “LESS THAN” the appropriate minimum or maximum readable value.
Example: Runway Three Six RVR more than Six Thousand.
When a readout indicates a rapidly varying visibility condition report the current value followed by the range of visibility variance.
Example: Runway Two Four RVR Two Thousand, variable One Thousand Six Hundred to Three Thousand.
