What to take into account in the management of slots according to the season

July 2018

Slot management at airports is carried out through biannual planning which is separated into two seasons: winter and summer. The Worldwide Slot Guidelines of the IATA (International Air Transport Association) set the standard guidelines worldwide for the allocation of slots to airlines, establishing a timetable that all the stakeholders must respect in order to ensure the optimization of airport operations; in other words, ensuring that the airport makes use of all available resources without reaching saturation.

In this task it is key to have powerful software for coordinating slots, such as Condor de Ikusi, which allows users to plan seasonal slots, monitor their compliance and make changes in real time.

WSG annual calendar for slot management

In general, the WSG determine the following guidelines for managing slots in the winter and summer seasons (northern hemisphere):

a) Slot management calendar for the winter season

  • April: in this month slot coordination agencies publish the list of slots with historical rights that are handed in to the airlines and collected from the airports which coordinate the possible changes in the limits of the capacity of the resources. In parallel, the airlines outline the slots they plan to apply for the following winter.
  • May: deadline for airlines to carry out their request for slots.
  • June: the coordinators close an initial proposal for granting slots, combining historical rights with the wishes of the airlines.
  • July: the IATA slot conference is held.
  • Mid-August: deadline for airlines to return slots they do not intend to use.
  • End of August: the coordinators carry out the relocation of possible slots on the waiting list or allocation of new slots based on the release of capacity for their return. The historical baseline is generated and will be used for the next equivalent season.
  • End of October: start of the winter season at airports.

b) Slot management calendar for the summer season

  • September: internal design of the slot agenda by airlines and communication of slots with historical rights by the coordination agencies.
  • October: open period for airlines to request slots.
  • November: slot coordinators make a provisional first distribution, before the IATA conference when the final planning will be set.
  • Mid-January: airlines return the slots they do not plan to use.
  • End of January: reassignment and generation of the historical baseline by the coordination agencies.
  • End of March: summer season begins.

Winter vs. Summer: what changes in slot management?

For the designation of slots in each season, the precedents of the previous equivalent season are taken into account. Thus:

• Airlines will lose their historical right to a series of slots if they have not operated at a minimum of 80% at the end of the season.

• Airlines can freely exchange the slots that have been allocated to them. This operation will be subject to the confirmation of the coordinating agency.

On the other hand, slot management incorporates certain distinctive features depending on whether it applies to the winter or summer agenda. Examples of these special features would be:

  • The widespread custom of transferring unused slots from the winter season to the summer season. It is worth recalling the recent case in the Amsterdam-Schiphol airport, in which they decided not to do so in order to better manage air traffic during peak periods in the summer; and that they have been ordered by the court to respect this tradition.
  • The typical winter season meteorological incidents that affect airport operations. For these contingencies, there is a winter airport plan that tries to prevent snow or ice accumulations, or to eliminate them as soon as possible, so that the airlines can comply with the stipulated flights.