FONTRAILLES (65) 31.10.2017

On 31 October 2017 at 18:05, 3 witnesses in a garden were surprised by a luminous point due east. They then noticed 3 white points apparently at the extremities of an anthracite-gray object. No sound was heard. The lights went out and the object disappeared completely. The witnesses observed an aircraft whose flight path remained directed toward them for a long time, making it appear nearly stationary. It approached with its landing lights on, producing a bright glow at nightfall, around 18:00. This was an Airbus test flight, not a scheduled service. Test flights often have unusual operating areas, altitudes and speeds, which created the witnesses' impression of strangeness. The intermediate altitude of 4,000 m and test-flight context may explain the use of landing lights, which are highly visible from over 100 km away. The attached reconstruction shows the long section of flight path directed toward the viewing location. It extends for over 60 km, corresponding to about 10 minutes at 200 kt, or 360 km/h as given in the source. Times and durations agree with the accounts within the uncertainty of a few minutes in both aircraft position reports and witness timings. The witnesses' UAP viewing direction, around azimuth 103°, reconstructed from T1's photograph containing ground landmarks and the Moon, matches the aircraft's direction. At the beginning the aircraft was about 100 km away, and at the end of the aligned section about 40 km away. At an altitude of approximately 4,000 m this corresponds to an elevation increasing from 2° to 5°, which the witnesses could perceive as near-stationarity. The end-of-sighting photograph of the UAP beside the Moon matches the aircraft's position relative to the Moon: the Moon was at 18° elevation and the aircraft at 5°. The UAP dimmed when the aircraft began changing heading and its landing lights lost their optimal alignment. The final disappearance of the lights corresponds to completion of the turn, with the aircraft then less than 30 km away. The witnesses reported distinct lights in a triangle near the end. T1 said, “The light gradually went out, letting us see that it was 3 lights in a triangle.” They could have resolved the aircraft's landing lights, on an A350/900 in this case: the 2 on the wings are about 12.5 m apart, while normal eye resolution is about 1/3,500 radian, or 8.5 m at 30 km and 6 m at 20 km. The plotted flight path does not establish the exact minimum distance. Under this hypothesis, the third light would be on the nose landing gear. During a test flight at this low altitude and speed, the gear could indeed have been extended. The triangle formed by the 3 lights has a height of 14.5 m and a base of 12.5 m. With zero aircraft pitch, the triangle tilts downward by 18° because the forward light is 4.5 m lower. But the aircraft is seen from the ground at 5° elevation, so the triangle is viewed at a grazing angle of 13° at zero pitch. In this configuration, the central light has an apparent separation of 7 m from the 2 lateral lights and can be distinguished. However, detecting that it is lower, and thus perceiving a triangle, is difficult, particularly if the aircraft has a nose-up attitude that reduces or even cancels the grazing viewing angle from the ground. Another phenomenon could explain the 3 points. They were distinguished as the initially single light faded: these were the landing lights fading from view as the aircraft turned. At 4,000 m altitude, the aircraft was still directly illuminated by the Sun, although the Sun was 2° below the local horizon at 18:05. During the heading change, the vertical tail and the 2 vertical wingtip winglets could have reflected sunlight like mirrors, whereas previously no flat aircraft surface faced the Sun. Alternatively, the bank angle during the turn might have positioned substantial areas of both wing undersides and the horizontal tail to reflect sunlight. Sunlight reflection better explains the ability to distinguish 3 points, with their greater separation of over 60 m and triangular arrangement. This is plausible but can neither be proved nor disproved. The remaining uncertainty cannot invalidate or even weaken the aircraft explanation, which matches the UAP's geometry and timing perfectly. There are 3 witnesses, but the overall account lacks substantiation in several respects. The questionnaires suggest possible mutual influence, with borrowed expressions and the use of “we.” Above all, despite repeated GEIPAN requests, the witnesses could not provide the original photograph files with attached metadata. The photographs therefore could not be used to establish or analyze precisely: - the picture-taking and observation times, essential for examining the reflection hypothesis further, which contain some inconsistencies or differences between witnesses; - the UAP's position in the sky; - whether the light was point-like or had a discernible structure. GEIPAN therefore classifies the case A: observation of an aircraft.