To whom should I address questions and/or complaints with regard to air traffic?
The airport Mediation Service is responsible for collecting, analysing and replying to complaints from local residents and communities concerning air traffic to and from Brussels Airport
What is a "Runway-in-use"?
The term “runway-in-use” indicates the runway or runways that, at a particular time, are considered by the control tower to be the most suitable for use by the types of aircraft expected to land or take off at Brussels Airport following applicable regulations.
Separate or multiple runways may be designated runway-in-use for arriving aircraft and departing aircraft.
What is a Preferential Runway System?
The term "Preferential Runway System" indicates the runway(s) to be used whenever possible as runway in use for arriving and departing aircraft at a defined time of the week. Various runway combinations are part of the preferential runway system depending of the time of the week (see topic “info on the runway”).
Who draws up the Preferential Runway System?
The Preferential Runway System is set by the federal authorities.
What could be a reason(s) for a deviation from the PRS ?
Deviation from the PRS may occur for various reasons:
Where is the surface wind measured?
Because wind conditions may vary, for topographical and obstacle reasons (e.g. buildings), the wind speed and direction are measured on different locations, especially near the thresholds of the various landing runways.
What is wind aloft?
Wind at low altitudes, in practice it is the wind the aircraft experiences right before landing.
What is Local MET Report?
Met Report is a routine observation message for a specific airport drawn up in “ICAO abbreviated plain language”. Those messages are only distributed at the airport itself and are destined for aircraft landing and taking off.
Why are cumulonimbus clouds (CB) and thunderstorms (TS) a reason for taking a different landing runway?
CB clouds cause severe turbulence; that is why they must be avoided at all times so as to not compromise flight safety.
Another phenomenon that is regularly (but not always) associated with a CB cloud, is lightning strike (LS). It is evident that a lightning strike on an aircraft may give cause to all kinds of technical problems.
If CB clouds are observed at the approach paths to the airport, ATS will choose the safest runway configuration in order for aircraft to avoid CB clouds as much as possible.
What is METAR?
METAR are routine observation messages for a specific airport drafted in WMO METAR code. Those messages are distributed internationally, updated every 30 minutes and destined for flight planning.
What is TAF?
The TAF (terminal aerodrome forecast) is a weather forecast product for a specific airport and is distributed internationally so that every pilot may be informed of the expected weather, wind, visibility and cloud conditions at the airport.
What is AMF/ACMET?
AMFs (Aerodrome MET Forecasts) are weather forecasts for a specific airport and for a specific period.
The Airport Capacity MET (ACMET) forecast indicates the expected capacity of the airport. It contains the information already mentioned in the AMF plus the cross and tailwind. Colour codes indicate whether a certain forecasted value is above or below the previously set limit value.
The wind values forecasted in the AMF/ACMET is the 10 minute average wind speed (and associated maximum) for the whole airport. So no separate forecasts are drawn up for each landing runway. Based on this value however, the cross and tailwind components per landing runway are calculated.
There is almost no wind but the aircraft still land on a runway that should not be in use according to the PRS
Not only wind speed and direction at the earth’s surface are taken into account. The wind in the lowest layers of the atmospheres is also very important. That is the so-called wind aloft.
How does the noise monitoring network at Brussels Airport work?
The 21 noise monitoring terminals permanently register the ambient noise on their location. An NMT does not only register noise from overflying aircraft but also from other noise sources such as road traffic, wind, voices, birds, …
To be able to distinguish aircraft noise from that of other noise sources a threshold value is set on each NMT. If the registered noise exceeds this threshold value during 10 seconds, we refer to it as a noise event. A noise event ends when the registered noise remains below the threshold value for 5 seconds.
A noise event is characterised by the time at which it occurred, the duration and maximum noise value attained.
To know whether or not a noise event was caused by an aircraft the central computer system that manages the noise monitoring network links the registered noise events to the radar data that were recorded in the vicinity of the NMT at the time of the noise event. This way we can find out what flight caused a specific noise event.
What are noise contours? Where can I find more information?
Air traffic to and from the airport causes a certain noise pressure. Depending on the distance from the noise source, its level can vary strongly between points.
Noise contours are lines of equal sound pressure. These Lines connect the points where equal sound pressure is measured or calculated. The noise contours with the highest levels are closest to the noise source. Further away from the noise source the sound level of the noise contours is lower.
In compliance with the stipulations in its environmental permit, Brussels Airport Company has the noise contours measured every year by an institution that is recognised by the Flemish Government for its expertise in the noise discipline. The annual noise contour reports since 2000 are available for consultation on http://www.brusselsairport.be/nl/env/noise_contours/.
Why does the website only provide data for 17 out of 21 BAC noise monitoring terminals?
The noise monitoring network managed by Brussels Airport consists of 21 noise monitoring terminals. The terminals NMT 1-2, NMT 3-3, NMT 15-3 and NMT 23-1 are located on the airport grounds and/or in the immediate vicinity of the runways or airport installations.
The noise events registered by these terminals also include ground noise, noise from overflying traffic or a combination of both. The attribution of the noise events registered by these NMT to specific flight movements is not always reliable. This is why the results of these noise monitoring terminals are not included on the website.
Who determines the flight paths?
The flight paths are determined by the Minister of Transport and/or the Belgian Civil Aviation Authority. The flight paths are communicated by means of instructions to Belgocontrol, which publishes them in the AIP (Aeronautical Information Publication)