Definition of Slot


The aviation industry knows 2 different types of slot which are not related to each other:

  • The air traffic control (ATC) slot is needed by each ATC regulated departing flight on the actual day of operation to avoid congested airways. This slot is only valid for this specific flight and for a specific departure time window of 15 min. In Europe the ATC slot is centrally coordinated and allocated by EuroControl in Brussels.
  • The airport slot is mandatory at coordinated airports for each movement (arrival AND departure) and is valid for a specific time at a specific weekday and for a specific period applied for. It is a permission given by the coordinator for a planned operation to use the full range of airport infrastructure necessary to arrive or depart at a coordinated airport on a specific date and time.
    Allocated slot times are based on the planned on-block (arrival) and off-block (departure) times. Actual times of arrival and departure may vary due to operational factors.

"Series of Slots"

A "series of slots"’ shall mean at least five slots having been requested for the same time on the same day of the week regularly in the same scheduling period and allocated in that way or, if that is not possible, allocated at approximately the same time. Only "series of slots" are eligible for later historic precedence;  requests or changes other than "series of slots" are considered "adhoc slots" and are not eligible for historic precedence.