The Pan Adria Incident is one of the most famous UFO cases from the former Yugoslavia. It reportedly occurred on 16 August 1977, when a Pan Adria Airways aircraft flying the route Zagreb → Belgrade → Titograd (now Podgorica) encountered a mysterious glowing object that allegedly remained alongside the aircraft for hundreds of kilometers.
The flight crew noticed a bright red-orange spherical light flying parallel to their aircraft and reportedly maintained a constant distance and altitude, matching the aircraft’s movements. The crew informed civilian air traffic control, which allegedly confirmed an unusual radar contact. Also military radar stations were reportedly alerted, and the object was also said to have appeared on military radar systems.
Witnesses interviewed years later, including former radar operators and military personnel claimed that the object displayed extraordinary acceleration.
According to later witness testimony, the Yugoslav Air Force scrambled MiG-21 interceptors to investigate but the UFO easily outmaneuvered the MiG-21 fighters, and one or more interceptors experienced serious problems, eventually a MiG-21 crashed and its pilot was killed after the encounter. However, this part of the story has never been independently verified through official military records and remains controversial.