LONGEVILLE-LES-METZ (57) 31.03.2018

At 19:37 on Saturday 31 March 2018, a witness at a window in Longeville-lès-Metz (57) saw an elongated white object moving rapidly and straight through a clear sky, described initially as heading southeast. He filmed it, then returned to his activities after 50 seconds. Only 1 account and its video were collected. GEIPAN identified an aircraft. The video showed it moving transversely across the view from the southeast-facing house. Reconstruction found an aircraft travelling southwest to northeast, parallel to the horizon at about 45° elevation, matching the video. The source's initial southeast direction thus differs from the reconstructed flight direction. The witness failed to recognise it despite aircraft noise audible in the video. He found its apparently low altitude unusual; GEIPAN states it was at 9,000 m, lower than cruise altitude. Its cigar-like shape was another concern. GEIPAN explains that low sunlight strongly illuminating the fuselage from the side, while the visible wing is edge-on to the light, can hide the wings. The source places the Sun due east despite giving an evening observation time; this inconsistency is unresolved. Finally, no contrail was visible, but GEIPAN notes that contrails are not universal and depend on atmospheric conditions and/or altitude. The case was classified A: aircraft.