A wave of sightings began on November 29, 1989, just outside of a small town of Eupen, Belgium, near the German border. Police officers Heinrich Nicoll and Euber Von Montige were on a routine patrol when they spotted strange lights in the sky. Pulling over, they saw a large triangular platform with large headlights lighting up a field below. They watched for over thirty minutes, until a second, similarly shaped object appeared and both flew away.

Thus began a wave of similar sightings over the next few months. Civilians reported a strange series of lights in the sky near Brussels. Suspecting it might be an experimental American aircraft being tested in Belgian skies without permission, the Belgian government made inquiries of the American embassy. The American embassy issued a statement, declaring that there were no unauthorized flights of American aeroplanes in Belgian airspace.

The most significant encounter took place on the night of March 30h, 1990. Following UFO reports and radar confirmation from multiple stations, two F-16s were scrambled to investigate. As they approached, the pilots saw two of the triangular objects, their lights shifting in color and an irregular sequence. The jets tried to lock onto the objects and succeeded briefly several times, but each time the UFOs would accelerate away at extraordinary speed.

In April of 1990, an anonymous man came forward claiming to have photographed one of the objects. In 2011, a man named Patrick M. came forward and publicly stated the photograph was a hoax created by him and some friends.

Wilfried de Brouwer, Air Force Major General (Ret.), was tasked with handling the official response to Belgian UFO wave. He wrote a chapter recounting his experience in UFOs: Generals, Pilots and Government Officials Go On the Record by Leslie Kean (2010).