Capacity and Runway Predictions

Whatever the weather: improving capacity and runway predictions 

The KLM Operations Control Centre (OCC) is the nerve centre of KLM. It’s here that all flights are planned and monitored, day and night. The OCC prevents delays and deploys smart tactics to eliminate them so that the timetable can be carried out as punctually as possible. Even in poor weather. This means that thorough insight into weather conditions is crucial, allowing the OCC to know in due time how many runways can be used and how. The new To70 system is a useful tool here.

High winds? Snow? Poor visibility? These can all cause delays. How can you predict runway use and capacity at Schiphol for the next 30 hours? The KDC asked To70 to develop a prototype system to this end. KLM’s OCC is its first user.

What will the weather be like today?

Schiphol has six runways for take-off and landing. Three different factors determine use of these runways: the weather, traffic and environmental regulations. In principle, it is therefore possible to predict how these runways will be used based on these factors. However, nothing is as unpredictable as the weather. And that’s why the Royal Netherlands Meteorological Institute (KNMI) issues a probability forecast for Schiphol. This probability forecast is a detailed weather report and includes the probability of reduced visibility and the uncertainty relating to the forecast wind direction and speed.

How do you deal with uncertainty?

The probability figure in weather forecasts determines the level of certainty with which you can predict runway use and capacity. This is why when developing the system we opted for a probability forecast for runway use and capacity. Users then receive a bandwidth of possible runway combinations. The system is accessible via a website and comprises two sections: a dashboard and a runway use model. The dashboard presents expected runway use based on the weather as input for the runway use model. The runway use model establishes the link between the conditions, the weather and the resulting runway use. 

A simple dashboard…

Arjen de Leege, Senior Aviation Consultant at To70, explains exactly how the system works. “The dashboard was developed in conjunction with KLM employees. We examined what information is relevant and how you can best display this.” The dashboard shows users at a glance an overview of the most probable runway capacity for the next 30 hours. “Users can then request detailed information per 20-minute period: how likely is it that a runway will be used?” 

… and a smart runway use model

To70 developed a smart model to come up with probability forecasts for runway use. “The model ‘learns’ by monitoring which runways are used in practice under specific weather conditions. This enables it to make a probability forecast for runway use and capacity based on the weather forecast.”  

The system enables us to work in a more targeted manner

The model has been extensively tested. Employees at KLM Flight Dispatch conducted simulations on the prototype system for five days from the past year. “Storms, snow and poor visibility affected runway use and capacity on these days. Flights were cancelled and aircraft required extra fuel in order to stay airborne longer.” The aim of the experiment was to compare the decisions users made based on the prototype and the decisions they made in practice. And what was the result? “The decisions taken in the experiment were more targeted than those in practice. Users could quickly see the times at which there was potentially insufficient capacity. And this allowed them to respond in a targeted manner.”

A major improvement!

The KDC and To70 are currently reviewing the options for further developing the prototype and expanding the number of users. To be continued! 

Figure 1 Dashboard – probability forecast for runway use and capacity

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