C7/8 Wet Runways / Snow and Slush

Question 1

Who is responsible for assessing runway surface conditions?

Answer 1

The Aerodrome Operator

Question 2

What are the reporting terms for wet runways and what do they mean?

Answer 2

DRY - not affected by water, slush, snow or ice
DAMP - surface shows a change of colour due to moisture
WET - surface is soaked but no significant patches of standing water are visible
WATER PATCHES - significant patches of standing water (>25% covered at a depth >3mm)
FLOODED - extensive patches of standing water (>50% covered at a depth >3mm)

Question 3

What different surface deposits are there?

Answer 3

Ice - in all forms
Dry snow - blown if loose
Compacted snow - resists further compression, holds or breaks into chunks
Wet snow - compressed into solid mass and sticks together
Slush - water saturated snow
Associated standing water - standing water produced as a result of melting

Question 4

What changes relating to snow and ice runway conditions are significant?

Answer 4

• change in surface deposit (water to ice, snow to slush etc)
• changes in depth: >20mm dry snow, >10mm wet snow, >3mm slush
• change in length or width of runway by 10% or more
• change in type or extent of deposit (reclassify NOTAM)
• change in distance of snowbanks
• change in serviceability of runway lighting
• other conditions significant according to local circumstances