In aviation, the allocation of slots used (Eng. niche, or " slots ") of the rationing of scarce air transport infrastructure. This airport slots and Airwayslots be distinguished.
An airport slot (german airport slot ) denotes a time window during which an airline may use an airport for takeoff or landing of an aircraft. Airport slots are awarded before the scheduling period.
The number of available airport slots depends on the capacity of the airport, which depends inter alia on the type and number of start and runways, the nature and duration of the passenger handling, weather conditions, and of temporal or spatial flight bans. The amount to be allocated slot is defined by so-called Eckwertsysteme that are set for a scheduling period in advance based on historical findings in consultation procedures with the participating institutions in Germany by the Federal Ministry of Transport, Building and Urban Development ( BMVBS).
The need for the coordinated allocation of slots is for airports with more aircraft movements are in demand as a result of the capacity are possible and which are therefore heavily used. Examples of such coordinated airports are London Heathrow and Paris Charles de Gaulle. In Germany, the airports in Berlin, Dusseldorf, Frankfurt, Munich and Stuttgart are coordinated.
Airport slots form the central basis of the timetable creation of airlines, as without the appropriate takeoff and landing rights, no flight can be conducted.
Airport slots are the most organized under a State authority airport coordinators for one season (summer season 30 weeks winter season 22 weeks) awarded. For a daily scheduled service 14 Slot series are necessary because each one slot for departure and approach is needed seven days a week. After the award of the slots can be traded to one between the airlines, but are not sold in the ratio of 1. Uses an airline the respective slot series for an individualized service to at least 80 %, it is entitled to the same airport slot in the next equivalent scheduling season ( summer or winter). This claim is also referred to as the " grandfather rights ".
In Europe, the slot allocation in the EU Regulation (EEC ) No 95/93, most recently supplemented by the EU Regulation (EC ) 545 /2009 regulated. Worldwide application have the IATA Worldwide Slot Guidelines.
During operation, it may lead to rationing of available air space or it is foreseeable that a destination airport will be overloaded. The reason for such a congestion can be for example bad weather. Then imposed centralized traffic flow control DNM ( Directorate Network Management, formerly CFMU ( Central Flow Management Unit )) of the Euro Control in Brussels called Airwayslots (also ATC slots). On the award of Airwayslots airlines have no control. Airwayslots have to start preparing aircraft ever a start time window in which the particular flight may start. In this way, the threat of capacity constraints held in the air to wait for economically and ecologically correct at the bottom of the departure airport. In operation, the airport slot, although the basis for planning the flight movements is, however, the possession of a Airwayslots forces may disobeying the scheduled departure time.