Between November 1989 and April 1990, thousands of witnesses across Belgium — primarily in the Eupen and Wallonia regions — reported large, silent, triangular craft with bright lights at their corners. The Belgian Air Force took the reports seriously enough to scramble F-16 fighters on the night of 30–31 March 1990, and Col Wilfried De Brouwer publicly briefed the sightings in a rare military acknowledgement. The wave produced the famous Petit-Rechain photograph, long considered the best evidence of a structured craft — until 2011, when photographer Patrick Maréchal admitted it was a polystyrene model he had painted and photographed. The Society for the Study of Space Phenomena (SOBEPS) conducted two investigations but reached no definitive conclusion about the craft's origin.