Automatic measuring of upper wind: Belgocontrol enhances security of approaches at Brussels Airport

Too strong a tailwind at high altitude can lead to an aircraft’s non-stabilized approach and can provoke a missed approach with overshoot (go-around procedure). In order to limit that risk Belgocontrol has developed a new tool that informs pilots and air traffic controllers on upper winds.

Wednesday, November 22, 2017 


Upper wind is often stronger than wind measured at ground level. If certain conditions are met (tailwind landings), the wind imposes a higher descent rate with the risk of a non-stabilized approach and the necessity to overshoot (missed approach). 

The wind direction and force at approach are presently transmitted automatically and in real time to the control tower by aircraft approaching Brussels Airport via the Belgocontrol radars. Before, those data were communicated via radio contact between the pilot and the air traffic controller on an ad hoc basis. 

The new tool that Belgocontrol has developed offers a better overview of the upper winds: the wind parameters are calculated by extraction of the mode-S radar data of the aircraft. That way accurate real-time wind measures can be obtained for various altitudes. Over 90% of aircraft landing at Brussels Airport are equipped with mode-S technology, allowing those data to be automatically transmitted. 

Crucial information for both air traffic controllers and pilots

For the past several months the new application has been tested at the Brussels Airport control tower. It will be fully operational at the beginning of December. It will offer the air traffic controllers a better and real-time overview of the situation at high altitude. That way, they will be able to guide the aircraft even more effectively in their landing. Thanks to the permanent observation of the evolution of the upper winds the security of the operations will be increased.

Within a few months Belgocontrol will provide the data on approach wind direction and force to both pilots and airline companies via the ATIS messages. Those coded messages contain crucial information on an airport, like meteorological data, runways in use, available approach and all other information the pilots need. Thanks to the new Belgocontrol tool pilots will be informed systematically and well in advance of the exact upper winds situation around Brussels Airport, even before they start their descent towards the airport. That will also contribute to improving security.