The Orly Airport Incident (1956)
On the night of February 17-18, 1956, Orly airport's radar locked onto an echo twice the size of the largest aircraft then in service, though no flight was scheduled. The object swung from complete stillness to 2,500 km/h, without any required navigation lights. For three hours, several crews — including one DC-3 briefly escorted by it — described a blinking light maneuvering at extreme speeds around their aircraft.
Witnesses
Air traffic controllers, pilots
Why it endures
A radar AND visual target simultaneously confirmed by several professional crews, with performance no aircraft of the era could match.
Official version (contested)
No convincing explanation was accepted by civil aviation. The file remains among France's unidentified cases.