| When more than 25 % of the runway surface area within the required length and width being used is covered by water, slush, snow or ice more than 3 mm deep |
| When 75 % of the required runway length and width are covered by contaminants such as snow, frost, ice or sand |
| When more than 50 % of the runway surface area within the required length and width being used is covered by water, slush, snow or ice more than 3 mm deep |
| When more than 50 % of the required runway length and width are covered by contaminants such as snow, frost, ice or sand |
EN 