Winter conditions

Winter weather presents particular challenges for everyone involved in aviation safety.

Air traffic control adjusts the airfield’s capacity according to the availability and condition (including icing) of runways, taxiways and parking areas and the provision of de-icing facilities.


The airport operator makes sure that infrastructure is cleared of snow and ice. In particularly severe weather, some infrastructure may be taken out of service. Clearance plans are drawn up in consultation with air traffic control and the airlines. The number of available runways, taxiways and aircraft parking areas is a critical factor in determining airfield capacity.


In snow or freezing temperatures, departing aircraft have to be de-iced. This is a treatment to remove any accumulated snow and ice and to prevent moving parts from freezing. Heavier or lighter forms of de-icing are used, depending upon the severity of the conditions. Which method is employed and the capacity of the de-icing facilities restrict the number of aircraft able to depart.


In wintry weather, it is important that the numbers of landings and take-offs remain roughly equal. This is to ensure that there are not more aircraft on the ground than the airport infrastructure (parking areas and so on) can cope with. Capacity limits are determined in consultation with all concerned – air traffic control, the airport, the de-icing contractor and the airlines – and they adjust their processes accordingly. In this situation, air traffic control usually follows the needs of the other parties.