Passenger jet's near-miss with UFO above Kent

A passenger jet coming in to land at Heathrow Airport in 1991 had a near miss with an unidentified flying object, according to newly-released Ministry of Defence files. The Alitalia captain was so concerned that he shouted "look out" to his co-pilot after seeing a brown, missile-shaped object shoot past the airliner.

The mysterious incident near Lydd in Kent was investigated by the Civil Aviation Authority and the military. Having determined that the object was not a missile, weather balloon or space rocket, the Ministry of Defence closed the inquiry and left the matter unsolved.

The unexplained close encounter is one of many recounted in military UFO documents made available online today by the National Archives. The 19 files, covering sightings from 1986 to 1992, include a US Air Force pilot's account of being ordered to shoot down a UFO that appeared on his radar as he flew over East Anglia. They also reveal that the MoD told Army and Navy helicopter pilots not to photograph crop circles for fear of undermining the official line that it did not investigate unexplained phenomena, and a letter from a woman claiming to be from the Sirius system who said her spacecraft, containing two "Spectrans" with "Mr Spock ears", crashed in Britain during the Second World War.

Perhaps the most intriguing episode is the near-miss involving the Alitalia jet at about 8pm on 21 April, 1991. The McDonnell Douglas MD80 was en route from Milan to Heathrow at 22,000ft with 57 people on board when the pilot, Achille Zaghetti, saw a strange object 1,000ft above him. He reported: "At once I said, 'Look out, look out' to my co-pilot, who looked out and saw what I had seen. As soon as the object crossed us I asked to the area control centre (ACC) operator if he saw something on his screen and he answered 'I see an unknown target 10 nautical miles behind you'."

Radar images showing the UFO were initial labelled "cruise missile?" but it was quickly established that it was not a military weapon. By 2 July, the MoD had concluded that the object did not come from Army firing ranges in the Lydd area and there was no known "space-related activity" that night.

An unnamed Whitehall official wrote: "It is our intention to treat this sighting like that of any other UFO and therefore we will not be undertaking any further investigation." There were, however, a number of other similar incidents recorded the same year.

The files can be accessed at www.nationalarchives.gov.uk/ufos