Runway contamination

Water = 3 mm

Ice or compacted snow = measurement not given

There is a limitation of when you cannot take off;

Dry ice/ dry snow/ wet snow

How much?

More than 15 mm of WET SNOW or WATER

More than 60 mm of DRY SNOW

More than 80 mm of VERY DRY SNOW

115% of runway is required if the runway is contaminated for destination.

3 types of hydroplaning;

1) Dynamic

2) Viscous

3) Reverted Rubber (eat on your own tyre)

For non-rotating tyre;

Viscous; 7.7 x square root of the tyre pressure in PSI

Dynamic; 9 x square root of the tyre pressure (if in bars x 14.7)

Coefficients of Friction

0.4 and above = good = 5

0.39 to 0.36 = medium to good = 4

0.35 to 0.30 = medium = 3

0.29 to 0.26 = medium to poor = 2

0.25 and below = poor = 1