Was it a bird? Was it a spaceship? No, it was a secret US spy plane (over Britain!)

Is it a bird? Is it a spaceship? No, it's a secret US spy plane
The Guardian

· Sightings of flying object over Britain worried MoD
· Questions threatened to strain relations with US

It is the stuff of internet conspiracy theorists' dreams. A top secret, hypersonic, cold war spy plane that was allegedly flown by the Americans in UK airspace without the government's permission.Publicly, the UK government played down newspaper stories about people who reported seeing UFO-like phenomena. But documents released under the Freedom of Information Act suggest the Ministry of Defence took the rumours much more seriously. Its investigations even threatened to strain the special relationship. "It does show that they were concerned that this thing did exist and the Americans were flying it around willy-nilly over the UK," said David Clarke, a social scientist at Sheffield Hallam University, who obtained the documents. "It certainly suggests that the British government suspected that they were being kept in the dark."

The United States has never confirmed the existence of the mysterious aircraft, called Aurora, which was supposedly designed to sneak at very high speed over the Soviet Union and take covert snaps of what the enemy was up to. It was rumoured to be capable of flying at up to mach 8 and so could reach anywhere on the planet in less than three hours. In the early 1990s there were a string of supposed sightings and strange sounds over Scotland which some bewildered locals attributed to UFOs. Rumours in the press that Aurora was operating secretly out of RAF Machrihanish on the tip of Kintyre prompted Scottish MPs to ask questions in parliament.

Briefing notes given to the then defence secretary Tom King on March 4 1992 show that civil servants did give the idea credence. "There is no knowledge in the MoD of a 'black' programme of this nature, although it would not surprise the relevant desk officers in the Air Staff and [Defence Intelligence Staff] if it did exist."

The response suggested to an MP's question was rather less revealing: "The existence of any such project (or operation) would be a matter for the US authorities." The Americans denied everything, but the reports kept coming.

The most credible witness was Chris Gibson, who had 12 years' experience with the Royal Observer Corps and was an expert on recognising aircraft. He saw a triangular plane flanked by two US fighters being refuelled in flight by tanker while he was working on the Galveston Key oilrig in 1989. The plane was unlike anything he had ever seen. "There was no precedent for this," he said. "I kind of sussed out that it was something I shouldn't have seen." He reported the sighting to Jane's Defence Weekly in 1992.

On December 22 1992, the air attache to the British embassy in Washington wrote to the assistant chief of the Air Staff in London explaining US reaction to renewed MoD questions prompted by Mr Gibson's sighting. "Secretary of the Air Force, the Honorable Donald B Rice, was to say the least incensed by the renewed speculation, and the implied suggestion that he had lied to Congress by stating that Aurora did not exist.

"As you will have gathered, the whole affair is causing considerable irritation within HQ [US Air Force], and any helpful comments we can make to defuse the situation would be appreciated."

"The sort of prickly reaction to people not believing their denials is pretty unusual," said Bill Sweetman, an expert on top secret US black projects with Jane's Defence Review. "They generally don't deny things actually because it generally doesn't hurt them too much if somebody thinks they have a capability they don't."

A further batch of sightings on March 31 1993 over Devon, Cornwall, South Wales and Shropshire prompted another investigation by the MoD. These turned out later to be a Russian rocket re-entering the atmosphere, but the MoD investigators at the time suspected Aurora. "There would seem to be some evidence on this occasion that an unidentified object (or objects) of unknown origin was operating over the UK ... If there has been some activity of US origins which is known to a limited circle in MoD and is not being acknowledged it is difficult to investigate further." Mr Sweetman suspects that by the end of the decade the MoD knew about Aurora. Another document from 2000 on the MoD's investigations into UFO sightings -or unidentified aerial phenomena as they prefer to call them - states that "some UAP reports can be attributed to covert aircraft programmes".

The section, which discusses other covert US aircraft such as the SR-71 Blackbird, contains two paragraphs and two illustrations which were censored before its freedom of information release last month. Codes next to the removed material indicate that it was excised in the interests of international relations. "Certain viewing angles of these vehicles may be described as saucer-like," the document says.