A triangle shape in Hautes-Pyr�n�es, France

On October 31, 2017 at 6:05 PM, three witnesses in a garden are astonished to see a bright point due east. The witnesses then notice the presence of three white lights that seem to be at each end of a anthracite-colored object. No noise is heard. The lights go out and the object disappears completely. The witnesses observed an airplane that was on a trajectory long oriented in their direction, which resulted in an appearance of near-stationarity in the sky. The airplane was moving toward them, lights on, and produced a bright glow at dusk (6 PM). This is not a scheduled flight, but an Airbus test flight. The area of operation, altitude, and speed are often unusual for these flights and created the strangeness condition for the witnesses. The intermediate altitude (4000 m) and the test context can explain the flight with lights on; these are very visible from more than 100 km. The attached reconstruction shows the portion of the airplane's trajectory long oriented toward the observation site. This trajectory portion is over a length of more than 60 km, which corresponds to a duration of about ten minutes (for an airplane flying at 200 kt, i.e., 360 km/h). The times and durations are consistent with the witnesses' indications, given the imprecision (a few minutes) of both the airplane position reports and the witnesses' timings. It is verified that the witnesses' observation direction of the UAP (around 103° azimuth, found from the photograph taken by T1 which contains ground references and the Moon) corresponds to the direction from which the airplane is seen. At the beginning of the observation, the airplane is about 100 km away, and at the end of the aligned portion the airplane is about 40 km away. This corresponds, for an airplane flying at about 4000 m altitude, to a height in the sky progressing between 2 and 5°, which can be perceived as near-stationarity by the witnesses. The photo of the UAP next to the Moon at the end of the observation shows a configuration consistent with the respective positions of the airplane relative to the Moon (the Moon is at 18° height when the airplane is at 5°). The attenuation of the UAP's intensity is caused by the beginning of the airplane's heading change and the loss of optimal alignment of the lights. The final extinction corresponds to the complete heading change, the airplane then being less than 30 km away. The witnesses report distinct lights in a triangle at the end of the observation. T1 says "the light went out gradually letting us see that it was three lights in a triangle." The witnesses were able to distinguish the airplane's lights (here an A350/900) since they are spaced about 12.5 m apart for the two on the wings, and the normal eye's separation capability is about 1/3500 of a radian, i.e., 8.5 m at 30 km, and 6 m at 20 km (the trajectory report does not allow knowing precisely what the minimum distance was). In this hypothesis, the third light of the triangle would be that of the light located on the nose gear. In a test flight at this low altitude and speed, it is entirely possible that the landing gear was extended. The triangle formed by the 3 lights has a height of 14.5 m and a base of 12.5 m. When the airplane is at zero pitch attitude, this triangle is tilted downward by 18° because the forward light is 4.5 m lower. But the airplane is seen from the ground at a sky height of 5°, so the triangle is seen at a grazing angle of 13° for an airplane at zero pitch attitude. In this case, the central light has an apparent distance of 7 m relative to the two lateral ones and can be distinguished. It is, however, difficult to detect a central light lower than the others and therefore a triangle, and even less so considering that the airplane may have a nose-up pitch attitude that would thus attenuate or even cancel the grazing angle of vision of the triangle from the ground. Another phenomenon can explain the three bright points. It is noted that they are distinguished when the initial single light dims. This light is then that of the lights, which dims until disappearing due to the airplane's turn. At its altitude of 4000 m, the airplane is still directly illuminated by the sun although located 2° below the local horizon (at 6:05 PM). During the heading change, the rear vertical tail and the two vertical winglets at the wingtips could have been in a mirror position to the sun, whereas previously the airplane presented no flat surface facing the sun. It is also possible that it is the roll angle caused by this turn that puts significant portions of the undersides of the two wings and the horizontal rear tail in a mirror position. The sun reflection hypothesis better explains the ability to distinguish three bright points by the large separation (more than 60 m) between the points and by the shape of a triangle. This explanation has its plausibility; it can neither be proven nor disproven. This element of uncertainty is not capable of invalidating or even weakening the airplane explanation, which corresponds perfectly in geometry and time to the position of the observed UAP. We have three witnesses. Nevertheless, the overall testimony lacks consistency on several points. The questionnaires reflect possibilities of influence between witnesses. There are borrowings of expression and the use of "we." Above all, despite the repeated request from GEIPAN, the witnesses were not able to provide the source files of the photographs with the attached metadata. It was therefore not possible to exploit these photos to, in particular, recover or precisely analyze: - the moments of shooting and observation (key element for deepening the sun reflection hypothesis), which are subject to certain inconsistencies or differences between witnesses. - the position of the UAP in the sky. - the structure (point-like or not) of the light. Consequently, GEIPAN classifies the case as A: observation of an airplane.