Glasgow A320 near miss with a blue and yellow object over Baillieston

Sunday, 2 December 2012. An Airbus A320 was inbound to Glasgow Airport. Air traffic control was guiding it onto the approach for runway 23. It was descending through 4,000 feet at 240 knots. The sky was clear. Visibility was more than 10 kilometres. The sun was behind the aircraft.

At 12:56 GMT, over Baillieston on the city's eastern edge, both pilots saw something "loom ahead". It was about 100 metres away. It showed a small frontal area. Both agreed it was blue and yellow, or silver, and "bigger than a balloon".

It was over in moments. The object "passed directly beneath before either of the crew had time to take avoiding action or had 'really registered it'". The pilot estimated it went 300 feet below, with no horizontal separation at all, and rated the risk of collision as "High".

The pilot called Glasgow. "Er yeah we just had something pass underneath us quite close and nothing on TCAS have you got anything on in our area." The controller answered. "Negative. We've got nothing on radar and we're not talking to any traffic either." Asked about a glider, the pilot suggested "well maybe a microlight" but added that "it just looked too big for a balloon."

The UK Airprox Board took the case as Report 2012166. Investigators found "no surveillance data to suggest a detectable object passing underneath the A320". The Glasgow unit's own radar replay showed nothing in the immediate vicinity.

The Board worked through the candidates. Without a primary radar return, a fixed-wing aircraft, a helicopter or a man-carrying balloon seemed unlikely. So did a glider, given the constrained airspace and the lack of thermal activity. Press summaries said meteorological balloons, hang-gliders, para-motors, para-gliders and parascenders were discounted too.

Members "were unable to reach a conclusion as to a likely candidate for the conflicting aircraft". The cause was logged as "Sighting report". The risk was graded D, the category for too little information. The crew had called it High.

The report surfaced in spring 2013. The Daily Mail, The Scotsman, The Courier, Gulf News, IrishCentral and IBTimes Australia all ran the story. The Daily Mail called the object "quite large" and said the Airbus could carry "up to 220 people", the type's capacity rather than a passenger count. IrishCentral brought in Carl Nally, founder of UFO and Paranormal Research Ireland, as an outside voice. Later, The Black Vault, run by John Greenewald, archived the Daily Mail text in a casefile dated 1 April 2015. Read against that date, the phrase "December 2 last year" has led to the encounter being misdated to 2014.

No photograph, video or released radio recording exists. Neither the pilots nor the airline were ever named. No one has alleged a hoax, and no specific debunking has appeared. The pilot's own guess, a microlight, remains the most down-to-earth suggestion on record.

Other cockpits would report similar moments. In July 2013 a Thomas Cook A320 crew near Heathrow saw a silver, rugby-ball-shaped object pass within a few feet, a case David Clarke wrote about. In May 2017 another Glasgow A320 met an orange light on final approach. The 2012 encounter remains what the Board called it. A sighting report. No candidate was ever found.