The Belgian UFO Wave: When a Country's Air Force Chased Triangles

On the evening of November 29, 1989, two Belgian gendarmes (federal police officers) named Heinrich Nicoll and Hubert Von Montigny were on routine patrol near the town of Eupen, close to the German border. They noticed a field alongside the road was illuminated so brightly it looked like a football stadium at night. When they pulled over and looked up, they saw a massive triangular object, dark and silent, with bright white lights at each corner and a pulsating red light in the center. It moved slowly, barely faster than walking speed, before accelerating and disappearing.

They weren't alone. That same evening, approximately 140 people in eastern Belgium reported seeing the same thing. Among them were at least 13 other police officers. Over the next several months, sightings continued to mount. By the time the wave subsided in April 1990, the Belgian Society for the Study of Space Phenomena (SOBEPS) had investigated over 650 cases and recorded 400 hours of witness testimony. The Belgian Air Force had scrambled F-16 fighter jets. And Major General Wilfried De Brouwer, Chief of Operations of the Belgian Air Staff, had gone on record saying his country had no explanation for what thousands of its citizens had seen.

The Belgian UFO wave remains one of the most well-documented mass UFO events in history, and one where the military response was unusually transparent.

What You'll Learn

• •Timeline: November 1989 to April 1990
• •What Did Witnesses Describe?
• •The Night of March 30, 1990: F-16s Scrambled
• •What Did the Radar Show?
• •The Belgian Military's Response
• •Was It a Secret American Stealth Aircraft?
• •The Skeptical View: Mass Hysteria and Misidentification
• •The Petit-Rechain Photo: Hoax Confirmed
• •Why the Belgian Wave Still Matters
• •Frequently Asked Questions

Timeline: November 1989 to April 1990

November 29, 1989: The wave begins. Approximately 140 sightings are reported in a small area of eastern Belgium around Eupen, Verviers, and the German border region. Witnesses include police officers, civilians, and a group of about 70 people in Eupen who watched the object for extended periods. The Belgian Gendarmerie takes the reports seriously and forwards them to the military.

December 1989: Sightings continue but become more scattered across Belgium. SOBEPS, a civilian UFO research organization, begins systematically collecting and investigating reports. The Belgian Air Force begins monitoring the situation.

January to February 1990: Sightings persist. Reports consistently describe a large, dark triangular or diamond-shaped craft with three or four bright lights. Witnesses emphasize the object's silence and slow movement. Some report the craft hovering before accelerating to extraordinary speeds.

March 30-31, 1990: The climactic event. Multiple radar stations detect unidentified targets in Belgian airspace. Two F-16 fighting Falcons are scrambled from Beauvechain Air Base to intercept. The jets obtain radar lock on targets multiple times but can't maintain contact. No visual sighting is made by the pilots. This event generates the most detailed technical data of the entire wave.

April 1990: Sightings gradually taper off. The wave effectively ends, though sporadic reports continue for some time. SOBEPS continues its investigation and eventually publishes two detailed volumes analyzing the evidence.

What Did Witnesses Describe?

The consistency of witness descriptions across hundreds of independent reports is one of the most striking aspects of the Belgian wave.

Shape: The object was almost universally described as triangular or delta-shaped. Some witnesses described it as more diamond-shaped or as having a flat underside with slightly raised edges. The size estimates varied, but many witnesses described it as very large, with some estimating a wingspan of 30 to 50 meters.

Lights: Three bright white or yellowish lights at the corners of the triangle, with a pulsating or rotating red or orange light in the center. Several witnesses described the lights as being powerful enough to illuminate the ground beneath the craft.

Sound: Virtually all witnesses reported that the object was silent or nearly silent. A few described a very faint humming sound at close range. This was particularly noteworthy because a conventional aircraft of the reported size would produce significant noise, especially at the low altitudes described.

Movement: The object's behavior was its most unusual feature. Witnesses described it hovering motionlessly, moving at walking speed, making sharp turns without banking, and then accelerating to extraordinary speeds with no visible exhaust or propulsion. The transitions between slow and fast movement were described as instantaneous, with no gradual acceleration.

Altitude: Reports varied, but many described the craft as being at very low altitude, sometimes just a few hundred feet above the ground. Several witnesses described it passing directly overhead at rooftop height.

The first night alone produced reports from over a dozen police officers, including some who observed the object for over an hour and coordinated their observations by radio.

The Night of March 30, 1990: F-16s Scrambled

The most dramatic event of the Belgian wave occurred on the night of March 30-31, 1990. Multiple radar stations, both military and civilian, detected anomalous returns over Belgium. Calls from citizens reporting the triangular craft confirmed that something was in the sky.

The Belgian Air Force scrambled two F-16 Fighting Falcons from Beauvechain Air Base at approximately 11:00 p.m. The jets were directed toward the radar contacts by ground control.

What happened next became the subject of intense analysis:

The F-16s' onboard radar detected targets on several occasions. According to the Belgian Air Force's official report, the jets obtained radar lock on objects that displayed extraordinary behavior. The targets appeared to accelerate from near-hovering speeds to over 1,000 km/h in seconds, change altitude rapidly (dropping from 3,000 meters to near ground level in moments), and make sharp directional changes that would be impossible for any known aircraft.

However, the pilots themselves never achieved visual contact with any object. They were chasing radar returns, not visible craft. The entire engagement lasted about 75 minutes before the targets disappeared from radar entirely.

The Belgian Air Force recorded the F-16 radar data and later made it publicly available, an unprecedented level of transparency for any military in dealing with UFO events.

What Did the Radar Show?

The radar evidence is both the strongest and most contested element of the Belgian wave.

The case for anomalous objects: The F-16 onboard radar locked onto targets multiple times. Ground-based radar stations also detected returns in the same general area. The apparent behavior of the targets (extreme acceleration, altitude changes, directional shifts) far exceeded the capabilities of any known aircraft. If the radar data is taken at face value, something was in Belgian airspace that could outperform every military aircraft on Earth.

The case against: The Belgian Air Force's own subsequent analysis raised significant caveats. The report noted that atmospheric conditions that night could produce false radar returns through a phenomenon called Bragg scattering, where temperature inversions in the atmosphere create layers that reflect radar beams and generate phantom targets. These false returns can appear to move, change altitude, and even accelerate, because they're reflections of the radar energy off moving atmospheric layers.

Furthermore, a critical detail emerged: on at least three occasions when the F-16s achieved radar lock, they were later determined to have locked onto each other. The "extraordinary maneuvers" recorded on those passes were simply the other F-16 doing normal flying.

The radar data is ultimately ambiguous. It might show genuinely anomalous objects performing impossible feats. Or it might show radar artifacts created by atmospheric conditions, combined with occasional locks on friendly aircraft. Without visual confirmation from the pilots, there's no definitive way to distinguish between these interpretations.

The Belgian Military's Response

What made the Belgian wave unusual wasn't just the sightings themselves. It was how the Belgian military responded.

Major General Wilfried De Brouwer, who served as Chief of Operations of the Belgian Air Staff during the wave, took the reports seriously from the beginning. Rather than dismissing the sightings or classifying the evidence, the Belgian Air Force cooperated with SOBEPS (the civilian research organization), released its radar data publicly, and allowed De Brouwer to speak openly about the events.

De Brouwer's initial hypothesis was that the objects were American stealth aircraft being tested over Belgium. He contacted American authorities, who, according to De Brouwer, "confirmed that no USAF stealth aircraft were operating in the Benelux area during the periods in question." NATO allies similarly denied any involvement.

In his later public statements, De Brouwer was careful not to claim the objects were extraterrestrial. He said: "The Air Force has arrived at the conclusion that a certain number of anomalous phenomena has been produced in Belgian airspace. The numerous observations, which have been confirmed by the reports of the Gendarmerie and by more than 400 hours of interrogation by SOBEPS, have led to the conclusion that the reported phenomenon cannot be attributed to a trivial cause."

This measured, transparent approach stood in stark contrast to the American government's standard response to UFO reports during the same period, which was typically to deny, deflect, or classify. The Belgian military essentially said: "We saw something, we investigated it, we can't explain it, and here's the data."

Was It a Secret American Stealth Aircraft?

The most popular conventional explanation is that the triangular objects were advanced American military aircraft, specifically the F-117 Nighthawk stealth fighter or possibly a prototype of what later became the B-2 Spirit stealth bomber.

In favor: The F-117, which had been operational since 1983 but was only publicly acknowledged in 1988, is a dark, angular aircraft that could appear triangular from certain angles. American military aircraft did operate from European bases. The triangular shape matches broadly, and a new or experimental variant might explain some unusual flight characteristics.

Against: The F-117 is loud. Witnesses consistently described silence. The F-117's maximum speed is about 1,000 km/h, it can't hover, and it can't make the sharp-angle turns witnesses described. The American government denied operating stealth aircraft over Belgium, and testing a classified aircraft over a densely populated allied nation would be an extraordinary diplomatic risk. De Brouwer specifically investigated this possibility and was reportedly satisfied that the Americans were not responsible.

The B-2 Spirit is a flying wing, not a triangle with distinct lights at the corners. And no known aircraft, classified or otherwise, can hover silently and then accelerate to supersonic speeds.

The Skeptical View: Mass Hysteria and Misidentification

Some have proposed several explanations for the wave:

Helicopters and conventional aircraft. Some analysts have suggested that the initial sightings could have been misidentified helicopters (which can hover and move slowly) or small aircraft with unusual light configurations. At night, in the absence of clear reference points, it's easy to misjudge the size, distance, and speed of lit objects in the sky.

Stars and planets. Belgian skeptic Marc Hallet argued that many sightings could be attributed to bright stars or planets (Venus was prominent during the wave period) viewed through atmospheric turbulence, which can make them appear to change color and move.

Media amplification. The wave received extensive media coverage in Belgium, which Some have suggested could have created a self-reinforcing cycle: media reports primed people to look for triangular objects, and once primed, they interpreted ambiguous stimuli (planes, satellites, stars) as UFOs. Each new report generated more media coverage, which generated more sightings.

Social contagion. Psychologist Marc Oremus proposed that the wave exhibited characteristics of mass psychogenic illness (commonly called mass hysteria), where the expectation of seeing something unusual causes people to genuinely perceive it. This doesn't mean witnesses were lying; it means human perception is more susceptible to suggestion than most people realize.

The skeptical case is strongest for the wave's later, more scattered sightings. It's weaker for the initial November 29 event, where trained police officers observed a structured object at close range for extended periods, and for the March 30 event, where radar stations independently detected anomalous returns.

The Petit-Rechain Photo: Hoax Confirmed

For years, the most famous piece of evidence from the Belgian wave was a photograph taken on April 4, 1990, in the town of Petit-Rechain. It showed a dark triangular object with three bright lights and a reddish center, matching witness descriptions perfectly. The photo was published worldwide and became an icon of the UFO phenomenon.

In July 2011, the photographer, identified only as "Patrick," confessed that the image was a hoax. He had photographed a painted Styrofoam triangle with embedded flashlights. SOBEPS, which had used the photo extensively in its publications, acknowledged the hoax and stated it didn't affect the rest of their investigation.

The Petit-Rechain hoax is an important cautionary element. It demonstrates that even organizations dedicated to serious investigation can be deceived by fabricated evidence. It also doesn't disprove the thousands of eyewitness reports, the police observations, or the radar data, but it removed what had been considered the wave's strongest physical evidence.

Why the Belgian Wave Still Matters

The Belgian UFO wave matters for several reasons beyond the question of what the objects were.

Military transparency. The Belgian Air Force's decision to publicly share its data and cooperate with civilian researchers set a precedent that influenced how other nations approach the UFO question. When the U.S. government began releasing its own UAP (Unidentified Aerial Phenomena) data in the 2020s, the Belgian model was frequently cited as an example of constructive transparency.

Scale of evidence. With over 650 investigated cases, thousands of witnesses (including trained observers like police officers and military personnel), radar data, and F-16 flight records, the Belgian wave represents one of the densest concentrations of UFO evidence ever assembled. Whether any of it proves the existence of unknown technology is debated, but the volume and quality of documentation is remarkable.

Unanswered questions. Over 35 years later, the Belgian wave still lacks a comprehensive conventional explanation. Individual sightings can be explained by misidentification or atmospheric phenomena. The radar data may reflect atmospheric effects. But no single explanation accounts for all the evidence, particularly the initial police observations on November 29 and the correlated radar/visual sightings across the wave period.

For another case where military pilots encountered objects performing impossible maneuvers, explore the Tic Tac UFO encounter involving USS Nimitz pilots in 2004. The Phoenix Lights of 1997 offer a similar pattern of mass sightings by thousands of credible witnesses. And the Rendlesham Forest incident represents another case where military personnel reported a close encounter with an unidentified object on European soil.

Frequently Asked Questions

How many people witnessed the Belgian UFO wave?

Estimates vary, but SOBEPS formally investigated over 650 cases involving at least 2,600 documented witnesses. The total number of people who saw something unusual is likely much higher, since many sightings went unreported. On the first night alone (November 29, 1989), approximately 140 sightings were reported in eastern Belgium.

Did the F-16 pilots see the UFO?

No. Despite multiple radar contacts and several radar locks, the F-16 pilots never achieved visual contact with any unknown object. They were pursuing radar returns, not visible targets. This is a crucial distinction: the radar data is ambiguous (potentially showing atmospheric artifacts), and without visual confirmation, the nature of the targets can't be determined with certainty.

Was the famous triangle photo real?

No. The Petit-Rechain photograph, taken on April 4, 1990, was confessed as a hoax by its creator in 2011. It showed a Styrofoam triangle with embedded flashlights. While the photo was widely published and became iconic, it was fabricated. Its exposure as a hoax doesn't affect the thousands of eyewitness testimonies but did remove the wave's most recognizable piece of physical evidence.

Could it have been the American F-117 stealth fighter?

This was the Belgian military's initial theory, but it was ruled out after American authorities denied operating stealth aircraft over Belgium. Additionally, the F-117 produces significant engine noise (witnesses reported silence), can't hover (witnesses reported hovering), and its maximum speed doesn't match the extreme accelerations reported by witnesses and suggested by some radar data.

Why did the Belgian government take the sightings seriously?

Belgium had a tradition of relatively open investigation of anomalous aerial phenomena, and the scale and credibility of the witnesses (including numerous police officers) made dismissal politically and practically difficult. Major General Wilfried De Brouwer has stated that the military felt an obligation to investigate reports that involved potential violations of Belgian airspace, regardless of what the objects turned out to be.