Oval object seen in Allonne

Summary

On October 9, 2013, two witnesses in Allonne (Oise) observed a dark object in the sky. They described an oval shape on top and a cylindrical shape on the bottom, at about 50 meters altitude, moving slowly and silently. Given the west wind that day, blowing at around 15 km/h, GEIPAN investigators considered it could be a helium balloon, perhaps one given to children. These balloons often have varied shapes and, when seen against the light, usually appear black. Due to its unusual but consistent appearance with known objects, the case was classified as category "B", meaning likely a helium balloon.