Friday, January 12, 2018

Some thoughts about the Calvine UFO incident.

The "Calvine UFO Incident" is one of Scotland's most celebrated UFO cases and thought to be one of the best reports of anomalous aircraft sightings in the UK.


For background I would recommend this article by Dr David Clark from which this summary is taken:

The.... incident occurred at 9pm on 4 August 1990, at Calvine, a remote hamlet on the A9 near Pitlochry in Scotland. According to the scanty details released by the MoD, two men saw a large diamond-shaped UFO hovering for about ten minutes before it disappeared upwards at great speed. During the incident military aircraft were seen making a number of low-level passes. One of the men had a camera and obtained six colour photographs showing both the UFO and at least one of the jets. The negatives were sent to the RAF Pitreavie and the Scottish Daily Record who passed them to the MoD.
The images were scrutinised by the MoD who identified the jet as a Harrier. They were also able to spot a second Harrier, but were unable to identify the large object clearly visible on the prints.....
In the event, it appears the Daily Record decided not to publish the story..... Nick Pope was the civilian opposite number of the DI55 desk officer during this period (1991-94) and he was the first to publish a brief account of the incident in his book Open Skies Closed Minds (1996). Pope described the photographs as “one of the most intriguing [UFO] cases in the MoD’s files”. He also describes how he kept an enlargement of one of the Calvine pictures on his office wall until it was taken down by his head of department.

The event came to prominence in 2009 when papers relating to it were released by the National Archive. There is no actual photograph, just a photocopy of a tracing of the photograph that was used for aircraft identification purposes:

Nick Pope did a reconstruction of the image he had seen which you can find along with a short video here.


I decided to apply my analytical skills to this case. For me this means looking at issues surrounding a story rather than the contents of the story itself. Doing this type of contextual analysis is something I learned at university (I studied Divinity) and it in the case of the Calvine UFO incident it highlights a number of issues with the story as it was originally presented.


First of all I looked at the date of the incident: 4th August 1990. This was a Saturday, an ideal time for two men to be out walking in the hills, but it also a significant historical date because only two days earlier Iraq had invaded Kuwait in what would become the first Gulf war. The US had started sending naval forces to the region on Friday 3rd August, the day before this UFO was sighted.

However, there is no independent evidence that the photo was taken on 4th August. The incident could have happened some time earlier and been misunderstood by the reporter.


The claim is that the photograph was taken at 9pm. However, when I looked up the time of sunset, the sun actually set at 9:17pm that night in Perthshire. Would there have been sufficient light to take the photograph as it has been described? The photograph described by Nick Pope is not typical of something taken around sunset in Scotland. The reconstruction (below) looks more like a typical  afternoon photograph. And another question: would two walkers have wanted to be up there knowing they had to come back down in the dark? I considered the possibility of a tourist getting caught out, but sunset in London that day was at 8:44pm so anyone from further south would have expected itt o get dark sooner.

If the time is wrong this does not bring the photograph into question but it does bring the recording of the story, and the alleged date, into question.

Identity of the known aircraft in the picture

The MoD apparently identified the aircraft as a Harrier, but did not indicate where it had come from - information that was bound to be recorded somewhere. Given that the number of Harrier's in service was finite I decided to track down as many of them as I could. This turned out to be simpler than I thought because a lot of information relating to the first Gulf war is in the public domain in the UK and US. The Harrier was mainly sold to the UK, US and Canadian military.

As far as I can tell their were seven British Naval and RAF operators of Harriers during that period. Here is a list of them and their statuses on 4th August 1990 as I understand them:

801 Naval Air Squadron, HMS Illustrious
This ship was a helicopter carrier and was not Harrier capable until 2003.

1 Sqdn (based at Wittering, Then Cottismore)
Most of their aircraft were onboard HMS Ark Royal which left Portsmouth on 3rd August to take part in an exercise called Operation TEAMWORK off the coast of Norway (see article here).

3 Sqdn - based in Germany, served in Bosnia

4 Sqdn based in Gutersloh, Germany
Was in the process of converting from Harrier GR3 to GR7 with some crew undergoing training at Dunsfold and some in Arizona (see this article here). They were not deployed to the Gulf and were not in full operation readiness until February 1991 (see this article here).

No 20 sqdn - Germany

1417 Flight - Based in Belize
No evidence that any of their aircraft were in the UK at this time.

1453 Flight - Based in Falkland Islands
This comes up in lists of Harrier deployments but the flight was actually disbanded in 1985.

Other sightings of Harriers in the UK
In addition to this Harrier's were occasionally reported by plane spotters at RAF Leuchars in Fife, which served as a refuelling stop over for RAF and friendly air forces as having its own operations. Part of the reason for this was the low flying ban which was in force in Germany at that time. 4 Squadron had regularly sent pilots to the UK to practice low flying. Most of this was around Salisbury Plain and was probably after the full conversion to GR7 aircraft:
As mentioned before, the low flying ban in Germany has caused some scrabbling around for flying of high training value. To this end, two detachments to RAF Kinloss have taken place, both successful. Pilots spend at least one night away a week somewhere in UK to take advantage of the now almost unique UK Low Flying System. Much FAC training now takes place on Salisbury Plain instead of LFAs 1, 2, 3 as in the good old days. The Dutch low flying routes are still available, but are of only limited value being totally flat and only one mile wide. (source)
Aircraft of all types came back to the UK at that time for low flying training and this included in Scotland.

There were also US operators of Harrier jets and at the time the US Air Force had bases and personnel in Scotland.

US Marine Corps
They called the Harrier the AV-8B. The AV-8B saw extensive action in the Gulf War of 1990–91. Aircraft based on USS Nassau and Tarawa, and at on-shore bases, initially flew training and support sorties, as well as practicing with coalition forces. However on 4th August 1990 The USS Tarawa was in the western Pacific and then sailed to Iraq (source). The USS Nassau was in the Philippines on that date as part of 4th Marine Expeditionary Brigade and had gone there directly from the USA (source). In addition to this the US AV8-B and many of the Royal Navy's Sea Harriers had been fitted with extra fuel tanks that hung beneath the wings. These are not visible in the photocopied line drawing which edges the likelihood towards this being RAF aircraft rather than a Naval one.

Harriers on test
With new GR7 Harriers being delivered around this time it is possible that new aircraft were sent out on test from Dunsfold.If this happened it is far more likely they would have been tested over Salisbury Plain rather than flying all the way to Scotland, but this is just speculation.

I think the two first questions that needs to be answered is "why a Harrier?" and "is the date correct?".

There were no Harriers based in Scotland on 4th August 1990. However, this was only two days after Iraq had invaded Kuwait - which could explain why the Daily Record never published the story. Newspapers were full of the Kuwait invasion at that point.

We know that 4 squadron, and other squadrons based in Germany, were sending pilots and aircraft to the UK for low flying exercises at this time. Mostly round Salisbury Plain, but it is entirely possible they had sent some pilots to Leuchars for a few days. Flying over the Scottish mountains at low altitude was considered much more realistic to combat situations and there were far fewer restrictions than there are today.

Having accounted for most of the British Navy's Harriers and all of the US ones were on exercise and were then sent straight to Iraq. This leads to another question: "Who was the pilot of the Harrier?" Nobody has ever spoken out about this incident.

Identifying the "UFO"

As relates to the unidentified object in the original photo it is hard to tell from the sketch version, but there is no scale so we don't know if it is a small object close to the camera or a large one further away. Because we are comparing it to the Harrier and we know how big it is then the object seem to be very large, but it might not be. You can see this problem in the reconstructed version of the image:

Could it have been an experimental aircraft on test? This did not seem like a possibility because of the remote location until I checked out all the Scottish RAF bases of 1990. RAF Edzell, which was quite close to this location in flight terms, was home to the 17th Space Surveillance Squadron of the US Air Force which operated their Low-Altitude Space Surveillance System. It is thought that Edzell’s detection system was used for testing stealth features on aircraft as well as for detecting potential incoming missiles. However, this was out of action from June 1990 to 1993 (as far as I can find out). So nothing definitive, but it certainly can't be ruled out.

There are known diamond shaped aircraft. Here is an example found on Google Earth (source of story):

List of possible explanations

1. This is an unidentified man made aircraft, possibly secret. It might even be a smaller unmanned aircraft close to the camera. Nick Pope has been clear that he was told that it was neither Russian or American, but given the secrecy they may not have told him. In this scenario the presence of the Harrier is purely coincidental. Both might have flown through the same low flying area from different locations (Edzell and Leuchars). I would give this explanation a 50% probability.

2. Hoax. The photographer could have hoaxed the photograph. Nick Pope saw a copy of it and it seemed real to him. The MoD also analysed it and felt it was genuine. When the Daily Record did not run the story the photographer did not go elsewhere for publicity which is something a hoaxer would surely have done? I can't rule out a total hoax, but it does not seem very likely, maybe 35% probability.

3. Disinformation. I know, I know, I know. I am not a conspiracy nut, but during a war it might have been necessary to pass off some sightings as "little green men" rather than disclose their real purpose. The photographers have never come forward, but if it was government disinformation it would not have been referred for MoD investigation. I think this explanation is probably 25% probability.

4. A real anomalous aircraft or UFO. This is entirely possible and I would put it at 50% probability.

Possible further investigation

I think there are a number of possible avenues for continued investigation of this incident without needing any access to official files:

  • Identify the photographer
  • Find out if the location it was taken from was a common route for walkers
  • Identify the Harrier pilot and the aircraft's origin
  • Look at any aircraft in production from around 2000 that look like the claimed UFO
  • Identify the journalist and find out what happened (although this is now 27 years later)
  • Check any files at the Daily Record if they have them


I think this shows the value of this kind of contextual analysis in cases like this. It is possible to find out a lot about a historical mystery by looking at the historical and social context. 

Update 2022: The Mystery is Finally Solved

Dr David Clarke has conducted a full investigation into this case and concluded that it was a US secret military aircraft. Amongst other bits of information he has been able to verify is that the photographers were poachers - which explains why they were on the hill at the time, and that there may have been a D Notice preventing the Daily Record from publishing. You can read his full article here:

The aircraft photographed probably went out of service in 1994 after a hard Landing at RAF Boscombe Down (article here).

Anyone interested in other diamond shaped aircraft might like to look up the earlier Lockheed Hopeless Diamond.