Brussels Overflight: 40 Years of Conflict, 450,000 Affected Residents

The conflict in brief

Brussels Airport (Zaventem), located 12 km from the centre of Brussels, has been at the heart of a conflict spanning more than 40 years between the airport's economic interests (24,000 direct jobs, 64,225 total jobs, 5.4 Bln EUR in added value) and the quality of life of 670,600 Brussels residents exposed to aircraft noise. The Superior Health Council estimates the health cost at more than 1 billion EUR per year.

The structural problem: prevailing winds (south-west, 70% of the time) require take-offs on runway 25R towards Brussels, overflying densely populated neighbourhoods. When the wind blows from the east, landings on runway 07L bring aircraft over the north-west of the city. And when the wind blows from the north, runway 01 brings aircraft over the east of Brussels.

In 2025, the airport handled 24.4 million passengers (+3.3% vs 2024) and 795,000 tonnes of cargo (+8.5%). Belgium has paid ~25 million EUR in cumulative penalties for aircraft nuisance.

The three runways and their noise corridors

Brussels Airport has three runways:

Canal Route (runway 25R)

Departures following the axis of the Brussels canal, impacting the centre and north of the Region. This is historically the most-used route (54% of all movements).

Crucke Route / RNP-07L

The most controversial route. Activated in summer 2025 as a "temporary alternative procedure" during airport works, it uses satellite navigation (RNP — Required Navigation Performance) for straight-in approaches on runway 07L. Unlike previous curved approaches, it concentrates 100% of flights on the exact same corridor, amplifying the nuisance.

Key data:

• 96% of RNP-07L flights violate Brussels noise standards
• 64 violation reports issued in a single month (January 2026)
• 450,000 Brussels residents affected (estimate by the mayors' joint front)
• Route extended until 31 October 2026 (repeated extensions since summer 2025)

The federal minister describes the RNP-07L as a "purely alternative procedure" rather than a "preferential route". Critics note it is activated even in moderate easterly winds (4-6 knots).

Runway 01: the eastern corridor

Runway 01/19 is the diagonal runway (south-north). Landings on runway 01 overfly Woluwe-Saint-Pierre, Kraainem, Sterrebeek and Wezembeek-Oppem at low altitude. Until 2004, runway 01 was only used exceptionally for landings.

The sharp increase is linked to the modification of wind thresholds (see section below). In December 2023, 1,400 residents of the eastern corridor won their case in court: 6M EUR in damages + 20,000 EUR/day in penalty payments as long as the situation persists.

Royal Castle of Laeken exclusion zone

Since 1954, a 1,500 m perimeter around the Royal Castle prohibits overflights. This prohibition, never challenged, forces flight paths to divert around Laeken — shifting the nuisance onto neighbouring municipalities. In 2024, the N-VA proposed lifting this exclusion during the Arizona negotiations; MR and Les Engagés refused.

Wind thresholds and Preferential Runway System (PRS)

The federal government imposes a Preferential Runway System (PRS) to distribute noise. The preferential runways are 25R, 25L and 19 (facing the prevailing south-westerly winds). Runways 01, 07L and 07R are non-preferential — they should only be used exceptionally.

The switching criterion is the tailwind threshold on runway 25: beyond the threshold, sKeyes activates a non-preferential runway. This threshold is at the heart of the controversy.

Chronology of threshold modifications

Key legal point: the Brussels Court of Appeal ruled on 22 October 2020 that the Wathelet instruction of 17 July 2013 is "the only legal, lawful instruction that does not violate any aviation regulation". All subsequent instructions were declared illegal. The State did not appeal to the Court of Cassation (March 2021). Yet in practice, sKeyes continues to apply the parameters from the illegal instructions.

Anticipation: sKeyes can activate a non-preferential runway up to 2 hours before wind conditions actually deteriorate, based on weather forecasts. This anticipation mechanism amplifies the use of runways 01 and 07L.

Timeline of court convictions

The Belgian State has been convicted 5 times in 20 years over Brussels overflight. The total penalties paid amount to ~25 million EUR:

The Brussels Court of Appeal also ordered the federal government to revise flight routes within two years, ruling that the current air traffic organisation harms public health and does not equitably distribute noise pollution.

Breakdown of the 25M EUR in penalties: Brussels Region ~13M EUR, 5 Flemish municipalities ~3.2M EUR, residents of the eastern corridor (runway 01) ~9.5M EUR.

Municipalities take action (March 2026)

Brussels municipalities

Mayors' joint front (9 February 2026): Schaerbeek, Molenbeek and Koekelberg demand:

• An effective ban on night flights between 11 PM and 7 AM
• The rerouting of heavy freight away from Brussels
• Priority for flight paths avoiding residential areas

Legal proceedings:

• Koekelberg (unanimous motion, 16 March 2026): first municipality to launch legal proceedings. Demands the abolition of the RNP-07L, a night ban from 10 PM to 7 AM, compliance with Brussels noise standards.
• Molenbeek joins the proceedings (19 March 2026).
• Jette (motion 4 March 2026, Ecolo-Groen/LBJette/MR-VLD majority): demands a return to the wind standards of the Wathelet instruction (17 July 2013) and has launched two legal actions — an environmental cessation action + a challenge to the permit before the Raad voor Vergunningsbetwistingen.

Flemish municipalities

Grimbergen, Machelen, Meise, Vilvoorde and Wemmel won their case in court against the State. Since May 2021, Belgium pays 50,000 EUR/week in penalty payments (3.2M EUR cumulative by July 2023). The Court of Appeal ruled that the current noise distribution constitutes a threat to public health.

Walloon Brabant municipalities

La Hulpe and Waterloo have also voted motions against overflight.

Citizen mobilisation

• Petition "No to intensive overflight of Northern Brussels": 6,500+ signatures (Change.org).
• Protest march on 8 March 2026 in Brussels against aircraft noise.
• 754 complaints for aircraft noise received by Brussels Environment in 2025 — nearly 4 times more than the previous year.
• 32,777 complaint cases filed with the federal mediator in 2025 (14.6M cumulative over 24 years).

Federal mediator crisis (March 2026)

Philippe Touwaide, federal airport mediator since 2001, was suspended for one month on 10 March 2026 by Minister Crucke.

Grounds:

• Conflict of interest: director of UBCNA (anti-noise association) from 2002 to 2015, while serving as mediator
• Conviction in June 2024 for harassment and defamation against the airport management (suspended sentence). Appeal to be heard in November 2026 by the Court of Appeal
• Hearing of 4 March 2026 (57th chamber of the Brussels criminal court): the prosecutor sought 2 years in prison. The defence pleaded acquittal. Verdict on 1 April 2026 at 9 AM

The minister also announced a review of the mediator's status (contractual vs. statutory).

Complaint for illegal works

On 18 February 2026, Touwaide filed a complaint against Brussels Airport for unauthorised extension works on a runway turning area during the summer of 2025. Brussels Airport acknowledged that the absence of a permit resulted from a "misinterpretation of the regulations".

Infringements 2025

In 2025, 6,075 infringements were recorded around Brussels Airport:

Breakdown of federal infringements:

• Aircraft banned at night
• Missing time slots
• Non-compliance with quiet night procedures
• Daytime departure procedures used at night

Boeing 777 cargo scandal: 200 entirely illegal night-time take-offs. Actual measured noise level: QC 10.7 (legal limit: 8.0). The aircraft used a fictitious QC of 7.7 to obtain authorisation. Subject to a judicial investigation.

Night flights without a slot: 1,032 (558 landings + 474 take-offs), down 29% over 3 years.

Health impact

Noise — Superior Health Council (May 2024)

The SHC published a scientific opinion on the health effects of air traffic. The health cost is estimated at more than 1 billion EUR per year around Brussels Airport:

• 160,000+ residents at increased health risk in Brussels
• Aircraft noise is more disruptive to sleep than road or rail noise at equivalent decibel levels
• Documented effects: sleep disorders, cardiovascular diseases (hypertension, myocardial infarction), stress and depression, reduced lung function, learning difficulties in children, pregnancy complications, increased risk of type 2 diabetes
• Recommendation: ban on flights between 11 PM and 7 AM

Ultrafine particles (air quality)

Beyond noise, air traffic emits ultrafine particles (UFP) that pose a distinct health risk.

Brussels Airport study (Atmospheric Environment, 2025): four measurement sites around the airport recorded concentrations of 6,500-14,000 particles/cm3 linked to aircraft, with peaks of 65,000-80,000 particles/cm3 during periods of high activity. Particles of 10-20 nm account for up to 65% of the total number. Taxiing and take-off contribute 50-64% of concentrations. The impact persists up to 7 km from the airport.

At the European level (Transport & Environment, 2024): UFP from aircraft are associated with 280,000 cases of hypertension, 330,000 cases of diabetes and 18,000 cases of dementia. 52 million Europeans — more than 10% of the population — live in particularly exposed areas. The particles, smaller than 100 nanometres, penetrate deep into the body: they are found in the blood, brain and placental tissue.

The SHC deliberately broadened its 2024 analysis beyond noise to include this dimension.

Recent international studies

• JACC (February 2025): people exposed to night-time aircraft noise show 7% greater left ventricular mass and 4% thicker cardiac walls, indicators of increased cardiac risk.
• Cardiovascular meta-analysis (2024): cardiovascular risk increases by +1.6% per 10 dB of aircraft noise. Atrial fibrillation: +2.7% per 10 dB. Heart failure: +2.3% per 10 dB.
• EEA (2025): transport noise in Europe causes 66,000 premature deaths/year, 50,000 new cardiovascular cases/year and 22,000 new type 2 diabetes cases/year. Noise is the 3rd environmental health threat in Europe, after air pollution and heat effects.

Fines: less than 20% collected

Of the ~32 million EUR in fines issued by the Brussels Region since 2000 (1,580 fines):

• ~6M EUR actually collected (less than 20%)
• 10.8M EUR definitively unpaid (abandoned)
• 6.3M EUR "unrecoverable" (but recoverable for 10 years)
• ~8M EUR under dispute

This collection rate raises questions about the effectiveness of the regional sanctions system. The Brussels government agreement provides for a direct fine recovery regime to address this.

Brussels government position

The 2026-2029 government agreement contains specific commitments on overflight:

• Extension of the night-time period to 10 PM-7 AM (currently 11 PM-7 AM)
• Tonnage limits for aircraft overflying Brussels
• Epidemiological study on the health effects of overflight
• Compensation fund for acoustic insulation of overflown buildings
• Creation of an independent noise monitoring body
• Direct fine recovery regime

The acoustic insulation fund is not yet operational. Unlike other European airports (Frankfurt: house buyouts and compensation within 350 m; Liege: insulation programme + buyouts; Berlin-Tegel: insulation forms for all residents; Dublin: targeted residential insulation aiming for -5 to 10 dB), Brussels Airport has no comparable residential acoustic insulation programme.

Federal-Flemish protocol (December 2025)

On 9 December 2025, the FPS Mobility and the Flemish Ministry of the Environment signed a cooperation protocol to reduce noise around Brussels Airport. Key elements:

• Joint steering committee + technical working group with BAC and sKeyes
• Formal channel for resident consultation
• Measures under study: revised flight paths, stricter night-time rules, incentives for quieter aircraft, acoustic insulation investments
• Stated objective: "reduce noise without hindering growth"

New night-time restrictions

• Summer 2025: noisiest aircraft banned from night-time operations
• Summer 2026: quiet night landings (1 AM-5 AM, weekends) authorised only for aircraft with QC ≤ 2

Alternatives and potential solutions

Freight transfer to Liege

Liege Airport handled 1.324 million tonnes of cargo in 2025 (+14%), operates 24/7 and is already Belgium's largest cargo airport. During disruptions at Brussels, operators already redirect to Liege. DHL transferred its European hub to Leipzig in 2008 after the refusal to extend night flights at Brussels — a departure that cost up to 1,700 jobs.

Continuous Descent Operations (CDO)

Continuous Descent Operations reduce noise by 1 to 5 dB per flight on the ground by keeping the aircraft higher for longer. sKeyes tested them in 2022 (runways 25R/25L, 11 PM-6 AM) with Brussels Airlines, TUI, Ryanair and DHL. European potential: 150,000 tonnes of kerosene saved/year.

Fleet modernisation

The Airbus A320neo is ~6 dB quieter than the A320ceo — equivalent to: 4 neo take-offs = the noise of 1 ceo take-off. Brussels Airport aims for 63% next-generation aircraft by 2032. The A350 and 787 operate several dB below the ICAO Chapter 14 minimums.

New ICAO standards (CAEP/13, February 2025)

Future aircraft must be at least 6 dB quieter (-30% noise). Effective date: 1 January 2029. A new Chapter 15 requires supersonic aircraft to meet standards equivalent to subsonic aircraft.

Balanced Approach procedure (EU)

On 27 January 2026, the Balanced Approach procedure (EU Regulation 598/2014) was launched, jointly led by the federal and Flemish governments. This mandatory procedure includes:

• A public consultation
• An opinion from the European Commission
• Assessment of 4 measures: noise reduction at source, land-use planning, operational procedures, operating restrictions

Quantified target: reduction of 30% of highly annoyed people and 30% of people with severely disturbed sleep by 2032 (compared to 2019).

It was triggered by the annulment of the environmental permit in July 2025. Flanders must re-decide by June 2029.

European context

Schiphol ruling (11 March 2026)

The Dutch Council of State (highest administrative court) annulled the cap of 478,000 flights/year imposed by the government on Amsterdam Schiphol Airport. Reason: insufficient justification for the measure. The night-time cap of 27,000 movements remains in force. In March 2024, a court had ruled that the treatment of Schiphol residents constituted a violation of the European Convention on Human Rights.

Comparative night curfews

International compensation

• Japan: 70 airports with noise charges. Kadena (Okinawa): 30.2 Bln JPY (~266M$) to 22,020 residents
• United States (FAA): more than 10 Bln$ invested in acoustic insulation, 143,000+ homes soundproofed
• 298 airports worldwide apply noise-based charges (including 143 in Europe)

WHO thresholds (2018, still in force)

The WHO recommends: Lden 45 dB (day-evening-night) and Lnight 40 dB (night-time). These thresholds are 10 dB stricter than the European Directive (Lden 55 dB, Lnight 50 dB). In Brussels, 670,600 people exceed the WHO Lden 45 dB threshold.

EU Zero Pollution target

Target: -30% of people chronically disturbed by 2030. Progress: only -3% since 2017.

Distribution of competences and community dimension

This is an emblematic case of Belgian institutional complexity: the airport is in Flanders, noise is a Brussels regional competence, aviation is federal, and the municipalities bear the consequences.

The linguistic dimension runs through the dossier: in October 2023, Flanders invoked a conflict of interest at the Concertation Committee against new routes, arguing that they shifted noise towards Flemish municipalities "without intergovernmental consultation". The Court of Appeal rejected the Flemish objection. IATA opposes a total curfew, citing Belgium's role as a European cargo hub. Les Engagés advocate banning night flights and the noisiest aircraft.

Citizen tools

Residents have several tools to inform themselves and take action:

• InfoBruit.brussels: regional noise information portal, including an aviation section
• BATC (batc.be): real-time flight radar (15-minute delay), noise data, noise contours, runway usage
• Bruxelles Environnement: network of 17 fixed stations of which 9 specifically measure aircraft noise (24/7)
• Complaints: electronic form via IrisBox (with eID) or PDF form by post/email. Complaints are recorded in a register that is analysed and regularly transmitted to the minister
• Airport mediation service (airportmediation.be): federal questions and complaints service

Issues to watch

• Touwaide verdict: 1 April 2026, 9 AM (Brussels criminal court)
• sKeyes study on alternatives to the RNP-07L: results expected April 2026. Impartiality contested by the municipalities
• Noise impact study: to be submitted by mid-2026 (court order)
• Concrete action plan: required by October 2026
• RNP-07L extension: currently until 31 October 2026 — will it be renewed?
• Return to the Wathelet instruction: demanded by Jette — only instruction ruled legal. Application in practice?
• Municipal legal actions: Koekelberg, Molenbeek, Jette in court; Flemish municipalities accumulating penalty payments
• Acoustic insulation fund: promised in the Brussels government agreement, not yet operational
• Balanced Approach: public consultation + European Commission opinion (horizon 2032 for -30% annoyance)
• Environmental permit: Flanders must re-decide before June 2029
• Night cargo flights: 200 cargo take-offs (Boeing 777) under judicial investigation. Transfer to Liege?
• Industry opposition: IATA, DHL and Singapore Airlines Cargo oppose a total curfew