[AERO VLG] DE NANTES (44) VERS ROME (IT.RM) 13.08.2013

On 13 August 2013, a passenger on a Nantes–Rome flight saw a vertical black shape projecting above the clouds several kilometers away to the aircraft's left. He likened it to a matte-black aircraft tail fin. Apparently stationary at first, it then turned horizontal and looked like a very thin black saucer. It disappeared after about a minute, but he photographed it. He estimated it as perhaps three times the size of an airliner or more. The neighboring passenger also saw it but declined to give an account. The witness did not discuss it with other passengers during the flight. Only one account was collected. The apparent strangeness lies mainly in the estimated size (see investigation report). However, the investigation notes that an unfamiliar object's size, distance and speed cannot be rigorously estimated, even by an experienced observer. Strangeness nevertheless remains high. The characterization relies mainly on the account because the photographs are too distant to show the UAP clearly. The case is atypical and unlike GEIPAN's familiar misidentifications. The source argues: - It was not a cloud: a compact black mass, first angular and then elliptical after slowly rotating about its long axis. - It was not an airplane or drone: too large according to the estimated distance and size, and without wings. - It was not a balloon or airship: it remained stationary at airliner-route altitude, stated as 'between 10 and 12, 000 m', apparently meaning 10, 000–12, 000 m. - It was not an asteroid or debris entering the atmosphere: it remained at the same altitude throughout. - It could not be mistaken for a celestial body, given perfectly clear weather, a pure blue sky and an azimuth of 0° relative to the observer's gaze, as expressed in the source. - It did not seem to be the aircraft's shadow on clouds, since such a shadow would appear on nearer clouds. The case rests on one human account, although an investigator's interview supported the witness's reliability. The photographs reveal no decisive detail establishing any flying object. Evidential strength therefore remains only moderate. Given the reported high strangeness, the available evidence does not permit a firm opinion about the sighting's origin. GEIPAN classifies it C: lack of reliable information.