Bentwaters–Lakenheath

What the file holds

Project Blue Book’s papers on this night make up one unit in the National Archives catalogue, “Bentwaters-Lakenheath, England, August 1956” (NAID 28966873, 44 images):

• the Project 10073 record card, with the comments of the Air Technical Intelligence Center (ATIC) (images 1–3);
• report IR-1-56 of the 81st Fighter Bomber Wing, dated 31 August 1956, on what was seen at Bentwaters between 2120Z and 2220Z on 13 August (images 4–9);
• an analysis by AFOIN-4E1 of 31 August 1956, signed by Colonel Gordon C. Hoffman (image 33);
• a memorandum of 17 October 1956 by Dr. J. Allen Hynek, “USAF UFO Scientist-Consultant” (images 27, 26 and 25, filed in reverse order);
• the two teletype messages that ATIC cites, “BOI-485, 16 Aug 56” from Lakenheath and “IDO-7335, 21 Aug 56” (images 36–43, out of order, most of them too faint to read on the scan);
• a letter that the retired watch supervisor of the Lakenheath radar centre wrote to the Condon study after 1 April 1967 (images 11–14);
• a hand-drawn plot of the sightings (image 44).

The Condon report of 1968 printed a transcription of Lakenheath’s message and of the supervisor’s letter, with the place names replaced by letters (Case 2). Where the scan of the message cannot be read, this page quotes that transcription and says so.

Bentwaters, 2120Z to 2220Z on 13 August

Report IR-1-56 (image 4):

“Most significant are the reports of three courses of UFOBS tracked on the Bentwaters GCA Radar. These UFOBS flew courses as follows: 1 group of 12 to 15 UFOBS FROM a point 8 miles SW of Bentwaters to approximately 40-45 miles NE of Bentwaters at an estimated speed of 80 to 125 miles per hour; a single UFOB was tracked by the Bentwaters GCA from approximately 25 miles SE of Bentwaters to approximately 15 miles NW of Bentwaters at a speed estimated at more than 4,000 miles per hour; a third UFOB was reported as tracked by the Bentwaters GCA from approximately 30 miles E. of Bentwaters flying a westerly course to about 30 miles west of Bentwaters at an exceptionally high speed.”

“The GCA Operators making these radar sightings were of the opinion that malfunctions of the GCA Equipment did not cause these radar sightings.” (image 4) The airman who put the single target’s speed “in the vicinity of 4000 miles per hour” added a second way to measure it: “each time the GCA antenna completed a revolution the Blip from this object moved 4 to 5 miles on the radar screen. The GCA antenna completes a revolution once every two seconds.” (image 8) Four to five miles every two seconds would be 7,200 to 9,000 miles per hour; that is our calculation, not the report’s.

Visually, the control tower shift chief at Bentwaters watched “An amber-colored object” through “7 X 50 binoculars” for “approximately 1 hour” (card, image 2). IR-1-56 puts his sighting “between 2120Z and 2220Z” and adds that “He was also aware that the Bentwaters GCA was tracking Unidentified Flying Objects by radar at this time.” (image 5) Two pilots of the 512th Fighter Interceptor Squadron, coming back from a T-33 flight, were sent to search for about 45 minutes and found nothing. “Both officers reported that they observed a bright star on the horizon to the east of Bentwaters which might have been mistaken for an Unidentified Flying Object by the visual observer.” (image 8) The report ends: “No physical evidence of the sightings is available.” (image 9)

Lakenheath’s message opens with another Bentwaters track: at 2255Z on 13 August Bentwaters’ GCA had a target cross from thirty miles east of the station to thirty miles west of it at 2,000 to 4,000 miles per hour, and the tower and the pilot of an aircraft overhead reported a bright light passing at the same time (image 41, legible only in part, and the Condon report’s transcription). IR-1-56, Bentwaters’ own report, covers 2120Z to 2220Z.

Lakenheath, 0010Z to 0330Z on 14 August

The record card (image 1): “Bentwaters station alerted RAF radar unit at Lakenheath. On 14 Aug the RAF unit reported objs were observed intermittantly from 0010Z to 0330Z, going from W to SW, stopping for 5 minutes, thence NW, disappearing from scope at 0330Z.”

Lakenheath’s message, in the Condon report’s transcription, lists “TS-ID, CPS 5, and CPN4 radars” on the ground and “Round white lights” seen by ground observers, who also reported “unusual amount of shooting stars in sky”, adding that “the objects seen were definitely not shooting stars as there were no trails behind as are usual with such sightings.” On the scan, the fighter is “BELIEVED TO HAVE BEEN A VENOM” (image 43). The passage on the intercept is on image 38:

“LAKENHEATH RATCC VECTORED HIM TO A TARGET 10 MILES EAST OF LAKENHEATH AND PILOT ADVISED TARGET WAS ON RADAR AND HE WAS ‘LOCKING ON’. PILOT REPORTED HE HAD LOST TARGET ON HIS RADAR. LAKENHEATH RATCC REPORTS THAT AS THE VENOM PASSED THE TARGET ON RADAR, THE TARGET BEGAN A TAIL CHASE OF THE FRIENDLY FIGHTER. RATCC REQUESTED PILOT ACKNOWLEDGE THIS CHASE. PILOT ACKNOWLEDGED AND STATED HE WOULD TRY TO CIRCLE AND GET BEHIND THE TARGET.”

The next page, image 39, cannot be read on the scan. The Condon report’s transcription goes on: “Pilot advised he was unable to ‘shake’ the target off his tail and requested assistance. One additional Venom was scrambled from the RAF Station. Original pilot stated; ‘clearest target I have ever seen on radar.’ Target disappeared and second aircraft did not establish contact. First aircraft returned to home Station due to being low on fuel.”

The chase was seen on the radar at Lakenheath and reported by its controllers; what the pilot said reaches the file only through their message. No statement by either Venom crew is in the file, and the record card does not mark “Air-Intercept Radar” among the types of observation (image 1).

The officer who wrote the message concluded, in the transcription: “My analysis of the sightings is that they were real and not figments of the imagination. The fact that three radar sets picked up the targets simultaneously is certainly conclusive that a target or object was in the air.” On the scan that part of the message is too faint to read.

What the file says about its label

The record card enters its conclusion on the “Other” line: “Anam. [sic] Propagation” (image 1). ATIC’s comment beneath it starts from the timing:

“At first glance, the 2 messages (TT Msgs BOI-485, 16 Aug 56 and IDO-7335, 21 Aug 56) reporting this sighting may give the impression that observations, radar, ground and air, were simultaneous. A review of detailed report IR-1-56, dtd 31 Aug 56, indicates that, although the observations took place within the periods given, they cannot be considered as concurrent.” (image 1)

“This is confirmed by the original report BOI-485, which states that the radar sightings occurred at a later time than the ground sightings.” (image 2) The comment then reads the radar tracks as “characteristic of weather returns and changing atmospheric conditions” (image 2), matches the amber object seen from the tower to Mars, cites the bright star that the two pilots said “could be mistaken for a UFO by visual observers”, and says of the Perseid meteors: “This undoubtedly accounts for some of the statements of ground observers” (image 3). It ends:

“CONCLUSION: On the basis of the above, and the limited data provided, there is no compelling reason to conclude that the radar UFO sightings were other than the result of anomalous propagation, which coincided with visual observations during this period. The inadvertant attempt to relate all the observations is not considered valid.” (image 3)

AFOIN-4E1 had written on 31 August 1956 (image 33):

“From the incomplete information submitted, it is impossible to make a definite determination of the sources of these sightings. Certain facts which are available, however, do tend to indicate that the targets were due to weather conditions.”

“The fact that the visual and radar sightings were not simultaneous tends to preclude the possibility of the targets being material targets.”

It named what was missing: “scope photographs, weather information indicating presence or lack of temperature inversion, moisture lapse data, and an accurate tabulation of related times and places of sightings (as between visual and electronic sightings).”

Hynek’s memorandum of 17 October 1956 opens: “It is to be regretted that so unusual a sighting report did not contain more factual material on which to base an evaluation.” He notes that the report “does not state whether it was definitely established that visual and electronic sightings referred to same object or even if they occurred precisely simultaneously” (image 27). On the meteors: “It seems highly unlikely, for instance, that the Perseid meteors could have been the cause of the sightings” (image 27). Hynek had discussed the case with Dr. F. L. Whipple, “director of Smithsonian Astronomical Observatory” (image 27), who pointed out the statement that “radars reported these facts to occur at later hours than the ground observers”; the memorandum says it “needs clarification inasmuch as it contradicts other portions of the report”, and reports Whipple as saying “that as far as the report at hand is concerned, no obvious physical solution is suggested.” (image 26)

The Condon report, 1968

The case study ends: “In conclusion, although conventional or natural explanations certainly cannot be ruled out, the probability of such seems low in this case and the probability that at least one genuine UFO was involved appears to be fairly high.” (Section IV, chapter 1, Case 2)

Gordon Thayer, in the report’s chapter on radar and optical analyses: “The probability that anomalous propagation of radar signals may have been involved in this case seems to be small.” And: “In summary, this is the most puzzling and unusual case in the radar-visual files.” (Section III, chapter 5)

How the story grew

• 1956, Lakenheath’s message. The fighter is “BELIEVED TO HAVE BEEN A VENOM” (image 43). The pilot reports the target on his radar, “LOCKING ON”, and then loses it; the tail chase is what Lakenheath’s controllers saw on their own radar (image 38).
• 1967 or 1968, the supervisor’s letter. Written after he retired on 1 April 1967 (the Condon report says it arrived in “winter 1968”), it puts the night “sometime between January and September (I can’t remember the exact date or month)” and has “Sculthorpe GCA Unit” make the first call (image 11), where the 1956 papers have Bentwaters; the Condon report notes that “he seems to have confused the identity of location C with B”. In the letter the pilot says: “Roger, Lakenheath, I’ve got my guns locked on him.” (image 12)
• 1971. COMETA quotes the end of an article by Thayer in Astronautics and Aeronautics: “it is also certainly one of the most disturbing UFO incidents known today.” (RG 255 413270, p. 17) The article itself is not among the documents this page can open.
• 1999, COMETA. “The pilot acquired the target visually and on radar, then lost it. The center then directed the plane 16 km to the east of Lakenheath; the pilot again acquired the target and said, ‘my machine guns are locked onto him.’” (p. 17) In the 1956 message the pilot is “LOCKING ON” his radar; guns appear only in the letter written more than ten years later.

Where it was

The pin is OpenStreetMap’s point for RAF Lakenheath (way 102826331), rounded by us to 52.40° N, 0.56° E. Lakenheath’s message, in the Condon report’s transcription, gives the station’s position as 52°24′ N, 0°33′ E. Bentwaters’ tracks ran up to about 45 miles from Bentwaters (IR-1-56, image 4), and the Venom was sent to a target 10 miles east of Lakenheath (image 38). The pin marks the station, not a position of any target.

Why this scores where it does

Witnesses: 4. Radar operators at both stations, the Bentwaters tower chief and two pilots, each placed by unit in the file; IR-1-56 rates its sources “usually reliable” (image 4). Not 5: the Lakenheath controllers and the Venom pilot speak in the file only through Lakenheath’s message, and the supervisor’s own account was written more than ten years later.

Radar: 3. Ground radar at both stations, with the operators’ own courses and speeds, and the Venom pilot’s reported contact on his radar. Not higher: no scope photograph, log or recording is in the file, and ATIC and AFOIN-4E1 both read the tracks as typical of weather returns.

Optics: 0. The card marks “Photos” as “No” (image 1).

Physical trace: 0. “No physical evidence of the sightings is available.” (image 9)

Multi-channel: 3. Ground radar at two stations, an airborne radar contact as reported, and sightings from the ground and the air. Not higher: by ATIC’s reading of IR-1-56 the observations “cannot be considered as concurrent”.

Documentation: 4. The card, Bentwaters’ report, two analyses and the consultant’s memorandum can be opened. Not 5: Lakenheath’s message is mostly too faint to read on the scan and is known in full only from the Condon report’s transcription.

Anomaly: 3. Speeds put at more than 4,000 miles per hour, targets stopping and starting, and a target that Lakenheath’s controllers saw follow the Venom. Each rests on one radar and one set of operators, and the file holds nothing to test anomalous propagation against.

Data today: 2. No scope photographs, logs or soundings. In 1956 AFOIN-4E1 already listed “scope photographs, weather information indicating presence or lack of temperature inversion, moisture lapse data” as missing.

The overall is 2.3: class C, material gaps.

What would settle it

• Atmospheric soundings for the night over both stations: the “weather information indicating presence or lack of temperature inversion, moisture lapse data” that AFOIN-4E1 asked for in 1956.
• “an accurate tabulation of related times and places of sightings (as between visual and electronic sightings)”, which would show whether the radar and visual sightings coincided.
• The logs of the Lakenheath radar centre and the RAF’s own records of the two Venom sorties. Neither is in the Blue Book file.