9th Feb 2008, 07:13
In ATIS broadcast when you hear R/W condition as Dry/Wet/ Wet ; understand it means first 1/3rd of the R/W is Dry and the second and third portion is Wet. Am I correct??
Thanks in advance
9th Feb 2008, 09:57
UK AIP explains it. I gather the reporting for each third of the runway was introduced because JAR-OPS requires an assessment of both touchdown and stop end (as opposed to all the ICAO rules which use one report for the whole runway).
There's a bit more info in another UK doc (CAP 168 I think) which explains about which parts of the runway are assessed for the report. From what I recall, the assessed area does not go right up to the edge of the runway in order that deeper water that collects in what are effectively drainage gutters is not counted.
Hope this helps
Runway Surface Condition Reporting
15.1 The following paragraphs describe the method by which the presence, or otherwise, of water and other contaminants on a runway is reported at UK aerodromes. Additional information relating to runways affected by slush, snow and ice can be found at AD 1.2.2 Snow Plan and guidance on the risks and factors associated with aircraft operations on runways contaminated with snow, slush and water is published in an Aeronautical Information Circular.
15.2 The presence or otherwise of surface water on a runway will be reported on RTF using the following descriptions:
DRY The surface is not affected by water, slush, snow or ice.
Note: Reports that the runway is dry are not normally passed to pilots. If no runway surface report is passed, pilots will assume the surface to be dry.
DAMP The surface shows a change of colour due to moisture.
Note: If there is sufficient moisture to produce a surface film or the surface appears reflective, the runway will be reported as WET.
WET The surface is soaked but no significant patches of standing water are visible.
Note: Standing water is considered to exist when water on the runway surface is deeper than 3mm. Patches of standing water covering more than 25% of the assessed area will be reported as WATER PATCHES.
For JAR-OPS performance purposes, runways reported as DRY, DAMP or WET should be considered as NOT CONTAMINATED
WATER PATCHES Significant patches of standing water are visible.
Note: Water patches will be reported when more than 25% of the assessed area is covered by water more than 3 mm deep.
FLOODED Extensive patches of standing water are visible.
Note: Flooded will be reported when more than 50% of the assessed area is covered by water more than 3 mm deep.
For JAR-OPS performance purposes, runways reported as WATER PATCHES or FLOODED should be considered as CONTAMINATED
15.3 When reported, the presence or otherwise of surface water on a runway will be assessed over the most significant portion of the runway. Details of the assessed area should be available from the aerodrome authority.
15.4 Runway surface condition reports will be given sequentially for each third of the runway to be used, for example, ‘Runway surface is WET, WATER PATCHES, WET’ or ‘Runway surface is WET, WET, WET’.
15.5 A brief description of any water patches greater than 9 mm in depth, which may affect engine performance, will be appended to a runway surface condition report. In such conditions, further information on the location, extent and depth of the water patches will be available from the aerodrome authority.
15.6 A brief description of any notable quantity of water outside the assessed area (eg: water collected at the runway edge) will be appended to a runway surface condition report.
15.7 When the runway surface is affected by dry or compacted snow or ice a braking action report (see AD 1.2.2 SNOW PLAN paragraph 5.4.1) will normally be available.
15.8 When a runway is contaminated by water (ie more than 3 mm), wet snow or slush, a braking action report will not be available due to the limitations of existing friction measuring equipment (See AD 1.2.2 SNOW PLAN, paragraph 5.4.2), however, a runway surface condition report will normally be available (see paragraph 15.2 for runways contaminated with water and AIP AD 1.2.2 paragraph 5 for other contaminants) stating the type of contaminant and its respective depth (See AD 1.2.2 SNOW PLAN, paragraph 5.2 and 6).
15.9 At Government aerodromes, runway surface conditions will be described in plain language, and where a braking action measuring device has been used, braking action will be described as GOOD, MEDIUM or POOR. The report may also include the type of measuring device used and the Mu value.
11th Feb 2008, 06:02
Thank you for a detailed ans