An “eloquent” criterion for the general public due to its apparent simplicity, airport capacity (aircraft or passenger flows the airport is capable of handling) has become one of the major issues in the airport development and planning debate. Capacity studies can have various aims:

  • In the context of infrastructure planning, they serve to establish long-term forecasting and regulation documents and provide the opportunity to decide whether short and mid-term projects are appropriate (new runways, relief lanes or service lanes, creation of parking areas, etc.).
  • Being included in airport coordination, they are performed in application of the EU regulation. In this case, the study aims to determine whether or not it is possible, within a very short time (less than 6 months) to alleviate saturation at peak times by adapting flight times. It must, where appropriate, enable the “scheduling” capacity available for the assignment of time slots to be determined.
  • The studies can also diagnose events that hinder traffic fluency (crossovers, direction of traffic, placement of de-icing pads, car park management, spacing due to wake turbulence, etc.).
  • They can be used to find out the environmental impact of traffic on the ground and in airspace, by calculating the fuel consumption and/or contaminant emissions.
  • Finally, a capacity study can provide a decision-making aid for choosing a new airport’s construction projects.

The capacity to challenge or to support the appropriateness of a project can thus be put forward. It is also a big selling point in the competition between the main airports. For example, the development capacity represented by the difference between an airfield’s maximum capacity and its current traffic has the potential to attract a company wishing to develop a hub.

Airport capacity is also a determinant parameter of the airport development project. Indeed, it is the observation that current capacity is not sufficient to absorb the known traffic that triggers new investments. Similarly, it is the comparison between the evolution of the capacity and the traffic forecast that allows upcoming investments to be programmed. The capacity calculation therefore occurs upstream of any big airport project - with technical, environment and financial studies - as a decision-making criterion for the appropriateness of making investments.

Airport capacity can also be used to demonstrate that only the coordination of flights can, in a very short space of time (placement of a hub, for example) provide satisfactory access to an airport to airline operators.

Expressed in a simple way, the capacity criterion must nevertheless be presented cautiously. Three main stumbling blocks should be avoided:

  • “Aren’t the hypotheses over-simplified?” The parameters constituting the airport capacity are numerous and complex. We must check that all the local parameters have been taken into account, and in particular we must content ourselves with an estimation based only on the description of the infrastructures.
  • “Are the results presented really comparable?” We must distinguish between several types of capacity: theoretical, operational and declared.
  • “Is the relationship between peak time traffic and annual traffic known?” We don’t go uniformly from an annual capacity (generally expressed in number of passengers per year) to peak time capacity (generally expressed in number of aircraft movements per hour).

Updated on February 2 2018