UFO reported by pilots in Vienne in 2007

Summary

On July 14, 2007, at 14:35 UTC, the captain of an Air France flight reported a T-CAS alert indicating a very close traffic. On the pilots' screens, a red dot appeared 55 km away and 100 meters above the aircraft, but no object was visually detected, despite excellent visibility conditions. Air traffic control also failed to detect any unknown traffic on radar. The preliminary investigation concluded the phenomenon was a false echo, and the GEIPAN analysis pointed to a possible malfunction of the onboard traffic alert and collision avoidance system (T-CAS).

This case was classified as "B" by the GEIPAN, indicating there were not enough elements to consider it an unexplained phenomenon. Although the pilots experienced an unusual situation, there was no visual or radar confirmation of an unidentified object. The most plausible explanation points to a malfunction in the aircraft's electronic systems, which is not uncommon in modern aviation, where false alerts can occasionally occur.