SECTION 2: CHAPTER 7 WET RUNWAYS

Question 1

Wet Runways

1. Introduction

Answer 1

It is recognised that a need exists to warn pilots of the presence of water on a runway.

1. 2 The Aerodrome Operator is responsible for assessing runway surface conditions.
2. 3 When the presence of water on a runway is brought to the attention of the controller, the information shall be passed to aircraft.

Question 2

Reporting Wet Runways

Answer 2

The presence or otherwise of surface water on a runway is to be reported on the RTF and ATIS, in plain language, using the following descriptions:

Question 3

DRY

Answer 3

The surface is not affected by water, slush, snow, or ice.
Note: Reports that the runway is dry are not normally to be passed to pilots. If no runway surface report is passed, pilots will assume the surface to be dry.

Question 4

DAMP

Answer 4

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.

Question 5

WET

Answer 5

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.

Question 6

WATER PATCHES

Answer 6

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 3mm deep.

Question 7

FLOODED

Answer 7

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 3mm deep.

Question 8

When reported, the presence or otherwise of surface water on a runway will be assessed over the most significant portion of the runway, i.e.

Answer 8

the area most likely to be used by aircraft taking-off and landing. This area may differ slightly from one runway to another but will approximate to the central two-thirds of the width of the runway extending longitudinally from a point 100 m before the aiming point to 100 m beyond the aiming point for the reciprocal runway. The assessed area may be different on runways with a displaced threshold or other unusual configuration, e.g. starter extension. The Aerodrome Operator is responsible for determining the exact dimensions and location of the area that is assessed.

Question 9

Reports of the runway to be used include, sequentially, the conditions in each third of the assessed area. For example

Answer 9

“Runway surface is wet, water patches, wet” or “Runway surface is wet, wet, wet”.

Question 10

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

Answer 10

In such conditions, further information on the location, extent and depth of the water patches will be available from the Aerodrome Operator.
2.5 A brief description of any notable quantity of water outside the assessed area, e.g. water collected at the runway edge, will be appended to a runway surface condition report.

Question 11

Unofficial Observations

Answer 11

Pilots of aircraft may report, or observations from the aerodrome control tower may indicate, that the amount of water present or runway surface condition is different from that being reported. Under no circumstances are controllers to pass to pilots information that suggests that the runway surface condition is better than the official report. However, when a pilot’s report or an observation from the aerodrome control tower indicates a worse runway surface condition this information is to be passed and identified as such.

Question 12

CALIBATED RWYS - Wet-surface friction characteristics of the runways at certain aerodromes have been calibrated to ensure that they are of an acceptable quality. If the quality deteriorates below an acceptable level the particular runway will be notified as liable to be slippery when wet.

Answer 12

When a runway, other than one notified as liable to be slippery when wet, is reported as damp or wet, pilots may assume that an acceptable level of wheel braking is available. When a runway is reported as having water patches or being flooded, it can be expected that pilots will make the necessary operational adjustments as wheel braking and control may be affected by aquaplaning.