What Is A Slot

The Network Manager covers the whole of Europe – from Ireland to Armenia and from Morocco to Finland. It handles over 10 million flights a year with summer peaks of over 34 thousand a day. That means an aircraft is taking off or entering European airspace every three seconds. Inevitably, there are bottlenecks. These may be in particularly busy bits of airspace or at some airports at some times of day. Any disruption, such as a runway out of action, fog, a thunderstorm or technical failure, can result in difficulties.

The Network Manager receives flight plans for all the commercial flights in its area and also receives the declared capacity limits for air traffic control centres and airports across the continent. So for example if an airport has snow or fog, it may reduce the rate at which aircraft can land. This is called a regulation.

The Network Manager then looks at the whole picture and problem areas are identified – where the demand is greater than the capacity.

One solution of course is to see if the capacity can be increased. So if a controller is covering a large area and the traffic is expected to be at the limit of how many aircraft can safely be handled at a single controller position, then that area might be split into two sectors, with two controllers/teams of controllers each covering part of the traffic.

However, there are limits to this process as sectors need to be large enough so controllers and pilots are not continuously handing over from one sector to another. You also need to have enough trained controllers to handle all the sectors. There are about 1,750 possible sectors across Europe.

The Network Manager will work with the local Air Navigation Service Provider to identify capacity constraints, sometimes well ahead, in order to optimise the sector configuration. One good example of this occurred recently when a new ATC system was being introduced in the southwest of France, in Bordeaux Area Control Centre. Neighbouring areas made sure that they had enough controllers to cope, with Spain providing summer levels of capacity in November. The result was that relatively few delays occurred.