Fifth Air Force Intel Summaries, June 1952: UFOs and Balloons Over Korea

What this record is

This is a month of Korean War operational intelligence: the numbered Daily Intelligence Summaries (DINTSUMs) issued by Headquarters Fifth Air Force “by command of Lieutenant General Barcus” from about 1 to 30 June 1952, with their daily flak supplements, airfield serviceability reports and vehicle-sighting tables. The PDF has 384 pages, many of them blank, and the summaries run in reverse order, from late June at the front to 1 June at the back. They were classified SECRET, and the file came to the Air Force Historical Research Agency as a copy from National Personnel Records Center holdings (index card, page 1 of the PDF, call number K720.059-48).

The bulk of it is war work: MiG sightings along the Yalu, F-86 and F-51 air combat, B-29 Shoran bombing of rail bridges, counts of trucks and locomotives on the roads and railways at night, rail cuts and bridge damage, flak positions, prisoner interrogations and estimates of enemy air strength. Dozens of entries concern “unidentified aircraft”, which in context are night intruders, enemy light planes or unplotted friendly aircraft. They are not counted as UFO material here. The index card’s abstract lists among the contents an “unidentified flying object… possibly balloon used as decoy or as means of orientation or signals by enemy ground troops”, and that, with a few other entries, is why the file is in the UAP transfer.

What it says about UFOs

About nine of the 384 pages carry UFO material, spread across six of the daily summaries. The pages are 37 and 39, 85 and 87, 131 and 133, 199, 247 and 373 of the PDF. They cover three separate subjects.

Two “unidentified flying objects”, 6 and 23 June. The fullest entry is paragraph 7c of DINTSUM No. 49 of 24 June (pages 85 and 87 of the PDF), headed “Unidentified Flying Objects”. It reports two similar sightings. The first was a ground observation at 1123 local time on 6 June at K-14, the Kimpo airfield near Seoul. The object looked like a coin, dull silver with a dark blue edge, about seven times as long as it was thick, and appeared to be spinning clockwise. It was reported moving at an estimated 300 knots, alternately turning through 360 degrees in seven seconds and then travelling on a spinning course for about 12 seconds. It approached K-14 from the north, paused, rose straight up for six seconds and disappeared into the sun. A few seconds later a second person at the same spot saw it moving rapidly south to north at about a 45-degree angle, pausing and returning, each time passing in front of the sun, and taking three seconds for each leg.

The second sighting was made at 1606 on 23 June by a pilot of the 18th Fighter-Bomber Group. His object was similar but black. It descended irregularly from 12,000 to 6,000 feet, flew level for six or seven seconds, came within about 1,500 feet of him and disappeared into cloud. He estimated its speed at about 250 mph and put its diameter at up to 20 feet (the lower figure of the range is lost at the page break). The Fifth Air Force intelligence comment says that no further information had been obtained, that no identification could be made and that Detachment 1 of the 6004th Air Intelligence Service Squadron was continuing to investigate “this unusual type of sighting”.

DINTSUM No. 52 of 27 June (pages 37 and 39 of the PDF) returns to both cases with a comment from Far East Air Forces intelligence, citing FEAF INTSUM No. 29 of 25 June. It says no logical explanation could definitely be given. The noon sighting overhead at K-14 suggested the possibility of refracted images of the sun through haze layers, and the pilot’s sighting could possibly be due to light reflecting on clouds, though the report did not say whether the clouds were above or below the aircraft. Detachment 1, 6004th AISS was trying to assemble complete information on “all such sightings”.

An F-94 and a brilliant light, 31 May. DINTSUM No. 26 of 1 June (page 373 of the PDF), at the back of the file, reports that at 0345 local time on 31 May, near grid reference CT 3510, a ground controller vectored an F-94 night fighter toward an unidentified object at 8,000 feet. The controller had no radar contact, but guards on duty at the station could see the object. The F-94, using its afterburner, traded quartering head-on passes with it, and neither could get behind the other. The two then circled in Lufbery manoeuvres to high altitude (the figure is partly illegible but appears to be 30,000 feet) and exchanged more passes for a few minutes. The “bogie” then accelerated to about 400 knots and was last seen heading 045 degrees. The encounter lasted 10 minutes, and the pilot kept contact only by a brilliant white light that also prevented him from seeing its outline, although he believed it was circular. He came within 500 yards and at times approached the speed of sound, in unlimited visibility. The summary suggests the bogie kept track of the F-94 by its silhouette against the dawn and by its afterburner flame, notes that an earlier report from the ground controller had described a circular object flying in the area, and says the 6004th AISS was investigating further.

The light over Hill 1290: a balloon. The third subject shows how such reports could be resolved. DINTSUM No. 36 of 11 June (page 247 of the PDF), under the heading “Enemy Balloons”, reports several sightings in the area of grid DT 204396 of an unidentified airborne object, white changing to red and then green. They were seen on 10 May and on 4, 6 and 7 June, between about 2120 and midnight, usually egg-shaped or round and at estimated heights of 1,000 to 10,000 feet. In one case it seemed to move very fast horizontally: tracked through a battery commander’s scope, it was measured over 10 miles of travel, and the operator could not traverse fast enough to follow it. On 7 June two intelligence specialists, one of them from Ordnance technical intelligence, watched it for an hour and five minutes. On 9 June a forward observer went to the area and saw a balloon being raised and lowered on a cable. The comment judges it a possible decoy for night-flying aircraft or a means of orientation or signalling for enemy ground troops.

DINTSUM No. 40 (page 199 of the PDF, mid-June) adds that the light was seen again at the same point near Hill 1290, with two enemy light planes that seemed to fly toward it after crossing friendly lines. Ground force opinion was that it was a light hung from a balloon as a checkpoint for enemy aircraft, or possibly a reference point for patrols. DINTSUM No. 46 of 21 June (pages 131 and 133 of the PDF) reports the interrogation of a captured soldier who, from his bunker on 25 May at about midnight, saw “a strange luminous object” apparently suspended about 500 metres above the top of Hill 1290, for about five minutes. Other soldiers saw it too, and none of them could explain it. The intelligence staff took this as corroboration of the captive-balloon explanation. Detachment 1, 6004th AISS was investigating.

Context

The summaries come from the build-up to the summer 1952 UFO wave, a few weeks before the Washington sightings in July. In Korea the Air Force had a field unit able to follow up: the 6004th Air Intelligence Service Squadron, whose Detachment 1 is named in every UFO entry here. The Kimpo and F-94 entries are the kind of raw field reports that passed up to Far East Air Forces and eventually to Project Blue Book at Wright-Patterson. Another Korean War sighting on the site, from October 1952, is recorded in FBI files on the western Korean front.

Status

These are front-line intelligence notes written within days, which gives them value and sets their limits. The summaries themselves offer mundane possibilities for two of the three subjects: a sun-glint or haze effect over Kimpo, reflections off cloud for the pilot’s sighting, and a tethered balloon with a light for the Hill 1290 sightings, which a forward observer confirmed. The balloon case is instructive. Trained observers with instruments recorded apparent speeds and manoeuvres that a cable-tethered balloon cannot perform, which is a warning about how much weight measured “performance” can bear in a night sighting.

The F-94 encounter is the hardest to dismiss from the page alone. Ten minutes of head-on passes with a light the pilot could not see past, seen from the ground by guards, is a vivid account. But the summary records no radar contact, no silhouette and no result from the 6004th’s investigation, and bright lights at night are notoriously hard to judge for distance and speed. Night pursuits of bright lights have sometimes turned out to be chases of planets or stars, and nothing on this page confirms or rules out that explanation. The file records what the Fifth Air Force was told and what it thought. The outcome of the investigations is not in it.

Sources

• National Archives catalog entry: https://catalog.archives.gov/id/659965426
• PDF of the record: https://catalog.archives.gov/medialz/electronic-records/rg-615/656595571/01135781_Fifth_Air_Force_Daily_Intel_Summary.pdf
• Series: Records from the Department of the Air Force Relating to Unidentified Anomalous Phenomena: https://catalog.archives.gov/id/656595571
• National Archives, Record Group 615 UAP records: https://www.archives.gov/research/topics/uaps/rg-615