MULHOUSE (68) 18.12.2015

In 2017, a witness reported a sighting from 18 December 2015 around 19:45–20:00. Near central Mulhouse (68), a fluorescent fuchsia light moved in a straight line, stopped, then resumed movement. No particular sound or object shape was discernible. It disappeared behind surrounding roofs. Only one account was collected. The case has adequate evidential strength, with a good description and a photograph reconstructing the sighting. Analysis suggests a recreational drone fitted with lights, operated under conditions the source describes as unauthorized: at night over a built-up area (see investigation report). The analytical text uses plural 'witnesses' despite the single account described at the start. Two main points support a drone: - Straight flight, an abrupt stop and immediate resumption at the initial speed are typical. Distance and low inertia would prevent small incidental movements during stopping and restarting from being resolved. - Fuchsia is a decorative color unlike conventional aviation lighting, fitting owner-customized drone lights. Distance, moderate motor noise, wind carrying sound away and surrounding traffic noise could explain silence. Distance and small size would also hide the drone's shape, leaving only its light. The source comments that fitting lights would not excuse violating night-flight and built-up-area restrictions, and that some owners take excessive risks of property damage or injury without appreciating the danger. These comments form part of the source's assessment of the proposed explanation. GEIPAN classifies the case B: probable observation of a recreational drone.