[D160] de FERRIERE (LA) (85) vers ROCHE-SUR-YON (LA) (85) 13.01.2017

On Friday 13 January 2017 at 17:45, a motorist traveling on the D160 from La Ferrière (85) toward La Roche-sur-Yon (85) noticed an intense white light in the clear sky. It disappeared for 15 to 20 seconds, then reappeared brighter than before. The sighting recurred a little farther along the route. Only 1 account was collected. GEIPAN considers these very probably reflections of sunlight from aircraft. The witness himself suggested this but was surprised by the small amount of apparent movement, while acknowledging that movement was hard to judge at a distance. He wrote that they seemed stationary but that distance might make their movements difficult to perceive. GEIPAN also notes that he was driving. The geometry was favorable for aircraft to reflect the Sun like mirrors. That evening, successive aircraft were flying in the same direction as the witness, heading toward the Sun at approximately 240°. The aircraft, Sun and witness were thus almost in the same plane. With the Sun on the horizon, its light could reflect from the underside of the fuselages, and particularly the wings, toward the witness. This effect depends on viewing geometry; changes as the aircraft moved could explain the appearances and disappearances. The 20-second interruption probably marked the end of the reflection from one aircraft and its appearance on another. The accumulated sighting lasted several minutes, but probably no more than 1 or perhaps 2 minutes continuously involved the same aircraft or group of aircraft. An aircraft initially observed at a 30° angle, according to the witness, would descend in apparent elevation to 20° after 1 minute and 15° after 2 minutes. This angular change is small and could have gone unnoticed. The attached reconstruction reproduces the final phase with 2 aircraft, one farther away and farther south than the other, matching the witness's description of a UAP lower down and farther left. GEIPAN therefore classifies the case as A: observation of aircraft, with the lights attributed to reflected sunlight.