The Airbus A320 was making its final approach to Glasgow Airport on 2 December when an object passed about 300ft underneath it.
The pilot of the aircraft said the risk of collision with the object, which did not show up on radar, had been "high".
A report by the UK Airprox Board said investigators were unable to establish what the object had been.
The A320 was flying with its landing lights on, in clear conditions and at an altitude of about 4,000ft above the Baillieston area of Glasgow, when the pilot and non-flying pilot saw an object "loom ahead" at a range of about 100m .... http://www.bbc.co.uk
