EPINAY-SUR-SEINE (93) 04.05.2015

On 4 May 2015, a date confirmed by the witness, at about 04:00, a witness who had just woken up was intrigued by a triangular shape crossing the sky, inferred from lights at its corners. The UAP passed at a right angle in front of his terrace, at the apparent height of a low-flying aircraft. He heard the sound of an aircraft flying low. No other account was collected. The phenomenon had many aircraft characteristics: steady white-yellow lights, flashing red and white lights, apparent size and sound. However, the witness could make out neither fuselage nor wings and perceived a triangle, which made the object seem strange. When observers see a group of points of light, they often interpret them as outlining an object. This shape or contour illusion can occur with independent lights, such as sky lanterns, or with aircraft whose wings are hard to see. The observer mentally reconstructs a dark volume bounded by the visible lights. The wings and fuselage may have been invisible because of the viewing angle, with the wings seen edge-on, or, more probably, because the aircraft was very dark, as large military transport aircraft can be. The extended centerline of one Le Bourget airfield runway passes through Épinay-sur-Seine, 7.5 km away. Météociel recorded a southwest wind at Roissy; the source therefore infers aircraft departures toward the west, in Épinay's direction (see the Météociel record). GEIPAN classifies the case B: probable aircraft sighting. Unfortunately, it did not process the case soon enough to check with air traffic control whether a flight had occurred at that time.