Sighting in Pithiviers, December 2, 1979

At around 6:30 pm, a couple out walking with their children noticed a great many lights of different colors in the sky, some of them flashing. The lights seemed to form a triangle, and a whistling sound could be heard. The phenomena first appeared stationary, then moved across the sky in single file and disappeared from view. Only these two testimonies were collected by the gendarmerie, whose inquiry amounted to retracing the witnesses' route on foot.

A re-examination of the case led to the hypothesis of a convoy of military helicopters heading for air base 123 at Orléans-Bricy. Single-file flight toward that base is typical of a military convoy, the pauses the witnesses mentioned are possible, and the green, red and yellow lights match the regulation lighting of aircraft. The flashing could come from fixed navigation lights seen close to flashing anti-collision lights, or from the geometry between the witnesses and the aircraft. Blue or violet lights, which are not part of mandatory aircraft lighting, may have taken on that tint depending on viewing conditions or the observer's eyesight. The triangular shape, reported by only one witness (the other spoke of three lights arranged in a triangle), is a perceptual illusion: at night, people readily join lights into a solid object. Hearing only a whistle is not impossible, but it cannot be demonstrated forty years later.

The case has weak consistency: no angular measurements, no sketches, no photos or video. This is nevertheless enough to support the hypothesis. The case, formerly classified D, is now classified B: probable observation of helicopters.