A passenger plane came close to crashing into a UFO in the skies above Glasgow.
An unidentified flying object rattled crew on the Airbus A320 as they came in to land at Glasgow airport in December.
According to testimony from the pilot, the UFO passed only 200ft beneath the plane while it was 4,000ft above the city.
Crew would have had no time to take avoiding action to avert a mid-air disaster had the UFO been on a collision course. By the time crew registered the unidentified craft, it had already passed below
Aviation experts are baffled by the incident because the UFO did not show up on radar on the Airbus or at airport control.
That means it is very unlikely to have been a winged aircraft or a helicopter, according to an investigation by the Civil Aviation Authority Airprox (air hazard proximity) department.
A hot air balloon has been discounted as a serious possibility because they avoid flight paths - especially near busy airports.
Small hang-gliders and para-motor craft would show up on radar.
The transcript of dialogue between the Airbus cockpit and an air traffic controller has been released.
A320 crew: "We just had something pass underneath us quite close [1255:30] and nothing on TCAS [traffic collision avoidance system]. Have you got anything on in our area?"
Ground Control: "Er, negative, er, we've got nothing on, er, radar and we're not talking to any traffic either."
A320: "Er, not quite sure what it was but it definitely, er, quite large [1255:40] and it's blue and yellow."
Ground Control: "OK, that's understood. Do you have an estimate for the height?"
A320: "Maybe, er [1255:50], yeah, we were probably about, erm, 400 to 500ft above it so it's probably about three and a half thousand feet."
The plane landed safely at Glasgow where the pilot revealed how close his craft was to a midair disaster.
He said: "We seemed to only miss it by a couple of hundred feet. It went directly beneath us. Wherever we were when we called it in it was within about 10 seconds. Couldn't tell what direction it was going but it went right underneath us."
The Airprox report concluded: "Investigation of the available surveillance sources was unable to trace any activity matching that described by the A320 pilot. Additionally, there was no other information to indicate the presence or otherwise of activity in the area.
"Members were unable to reach a conclusion as to a likely candidate for the conflicting aircraft and it was therefore felt that the board had insufficient information to determine a cause or risk".