T-CAS alert with no visible object on Air France flight over Jazeneuil

Summary

On July 14, 2007, at 14:35, the captain of an Air France flight received a T-CAS collision-avoidance alert indicating a very close object. A red dot appeared on the cockpit screens at 55 kilometers and 100 meters altitude, yet no crew member could see anything despite excellent visibility. Air traffic control detected nothing on radar either.

The preliminary inquiry pointed to a false echo, and GEIPAN's subsequent analysis supported a malfunction of the T-CAS system itself. Such false alerts, while uncommon, are not unheard of in modern aviation. The case was classified as B, with no elements suggesting an unexplained phenomenon.