DOW-UAP-D163, Air Intelligence Information Report, Sweden, 1953
This document is an Air Intelligence Information Report (AIIR), a standardized U.S. Air Force reporting form used to record raw information of potential intelligence value for later analysis. The form served as a primary vehicle for U.S. Air Force field intelligence collection throughout the early Cold War, until defense-wide reporting standards were established in the early 1960s. This AIIR records a December 17, 1953, incident near Hässleholm, Sweden, translated from a local media report. At 1437 hours, Transair chief pilot Captain Ulf Christiernsson and crew chief Olle Johansson reported observing an object approaching their DC-3 from the opposite direction, approximately 600 meters (1,969 feet) below their aircraft, which was flying at about 2,150 meters (7,054 feet). The aircrew described a “shining metal spherical elliptical object” and estimated its speed as approximately the speed of sound. Christiernsson described the object as strongly metallic, nearly round, and slightly elliptical. He reported that it remained visible for six to seven seconds, produced no visible exhaust or condensation trail, and initially appeared to him to be a jet or possibly an unmanned “robot.” The Swedish Defense Staff reportedly identified no Swedish aircraft in the area at that time and stated that it would examine possible radar observations. The report also includes a brief character sketch of Christiernsson based on the account of a personal contact, who characterized him as “most untrustworthy,” and notes that Swedish authorities had begun an investigation into the incident. All descriptive and estimative language contained in this report reflects the reporter’s subjective interpretation at the time of the event. Such characterizations should not be interpreted as a conclusive indication of the presence or absence of any intrinsic object features or performance characteristics. AARO Comment: Based on the reported aircraft altitude and relative separation, the object’s reported altitude was approximately 1,550 meters (5,085 feet). Under standard atmospheric conditions, the speed of sound at that altitude is approximately 748 mph.
The summary above is sourced from the released file metadata as published to war.gov. The analysis sections below are original to this tracker.
Text of the document
Machine-extracted from the PDF war.gov published (its text layer or OCR), so expect errors, especially in names, numbers and handwriting; the PDF is the authoritative copy. Lines that did not extract as readable text are left out. Showing about 992 words from pages 1, 2, 3 of 3.
PAGE 1
AF FORM 112
COUNTRY REPORT NO.
AIR INTELLIGENCE INFORMATION REPORT
nny1ng Saucertt Sighted By S1red1sh Pilot
AREA REPORTED ON FROM (..49=CV)
SWeden OAirA, Stockholm, Sweden
DATE OF REPORT DATE OF INFORMATION l
PREPARED BY ( Office,) SOURCE
BURT R()VEN Ma or USAF MC IPress and P rsonal Contact
SUMMARY: (Ellter omcise ~mmar11 of report. Gwe •lgnlftcanu Infinal 0110-,ente11« paragraph. Li& lnclorure• at lower le/I. B PAGE 2 AF FORM 112-PART II
r • 'AIR INTELLIGENCE INFORMATION REPORT
FROM (Agencu) REPORT NO.
PAGE OF PAI.ES
1. On Thursday, 17 December 1953., while flying near HHssleholm, SWeden, Captain
Ulf Christiernsson sighted an 11 unknown" object. The follorring is the translation of
a newspaper account of the incident:
"The chief pilot of Transair, Capt. Ulf Christiernsson, and his crew
chief, Olle Johansson, had a strange meeting over HHssleholm at 1437 hours
Thursday. A shining metal spherical elliptical object came toward them
traveling in the opposite direction from their machine at an estimated speed
of sound and approximately 600 meters below their DC-3, which was on its way
from Bulltofta to Bromma. It was visible six to seven seconds; Capt. Chris
tiernsson, who had good silhouette recognition, stated that what he saw was
something absolutely new, possibly an unmanned robot.
11The Transair plane was automatic controls when the meeting occurred.
Capt. Christiernsson did not have time for any measures other than to report
to Bulltofta and the Defense Staff, which later sent out the following com
" •'rhe air crew of a civil aircraft observed on Thursday at 1437 hours
over the area of HRssleholm an unknown object moving in the opposite direction
from the airplane. The object was observed for six to seven seconds. At that
time and altitude the weather was clear. Because of the low lying cloud for
mations the object is not thought to have been seen from the ground. The De
fense Staff does not know o.f any Swedish plane that was in that area at the
time in question. An investigation is being conducted.•
"Previously I have been extremely skeptical about all the stories of
mysterious objects -- called flying saucers -- that have been seen at diverse
points, said the Captain. Now I don't know exactly what to think; but it did
seem to me that we had seen a robot of some kind. When I first caught sight
of the object, which like us was in the civil air corridor, I thought it was a
jet. We had, however, received no word that any such thing was on the way.
"The object came toward us at what I would say was the speed of sound;
we were flying at an altitude of approximately 2,150 meters and the object was
around 600 meters below us. It was going in a southwesterly direction and
disappeared after six or seven seconds.
•tThe object had a strong metal shine; the crew chief, Johansson, who coulc
see it longer than I, thought it was almost phosphorescent. The flying weathel
was excellent above the clouds, which were at an altitude of about 1500 meters,
and the sun was shining brightly. The object was proceeding just above the
"The first silhouette I got diagonally from the right was narrow. When
it was nearly directly under us, however, I saw that it was nearly round, just
slightly elliptical.
"The object, which could definitely not have been a meteor, gave off no
waste gases or condensation traces.
11Was I afraid? No, but curious, very curious, concluded Captain Chris
ItChristiernsson has seen just about everything in aviation and has very
good silhouette recognition. From 1942 to 1946 he was a volunteer serving in
NOTE: THIS DOCUMENT CONTAINS INFORMATION AFFECTING THE NATIONAL DEFENSE OF THE UNITED STATES WITHIN THE MEANING OF THE ESPIONAGE ACT. 50 U. S. C.-
3I AND 32. AS AMENDED. ITS TRANSMISSION OR THE REVELATION OF ITS CONTENTS IN ANY MANNER TO AN UNAUTHORIZED PERSON IS PROHIBITED BY LAW.
IT MAY NOT BE REPRODUCED IN WHOLE OR IN PART, BY OTHER THAN UNITED STATES AIR FORCE AGENCIES, EXCEPT BY PERMISSION OF THE DIRECTOR OF
INTELLIGENCE. USAF. PAGE 3 'AIR INTELLIGENCE INFORMATION REPORT
FROM (Aomcr) REPORT NO.
OAirA. Stockholm, Sweden m.-12 PAGE OF 3 PA~ES
the Royal Air Force. He finished as a captain in the British Air Force, after
making some thirty raids in a Mosquito against enemy territory, in both North
Africa and Italy.
"Air Force Chief, General Nordenskiild, announced that it had been ascer
tained that the object could not have been any Swedish aircraft.
•• 'We are now investigating/' he continued, 'what our radar stations might
2. Captain Christiernsson is 41 years of age and was born in sl
Where this file fits in the PURSUE archive
This file is one of DoD's 282 files in the Trump PURSUE disclosure. Within the DoD agency block it ranks #169 of 282 by Anomalousness Index. Across the entire 478-file archive it ranks #293 of 478.
That places it in the lower-scoring band of the archive (293 of 478 by score), typical of investigative-record style files where the report is paper-based rather than instrumented.
Anomalousness Index: 56/100
Evidentiary weight that this encounter remains unexplained after conventional analysis. Not a probability of extraterrestrial origin - that number is not honestly computable from the released files and this tracker refuses to publish it.
🤖 AI-ASSISTED SCORING · methodology
The six rubric components break down for this file as follows. Each component has a weighted contribution to the final score; the per-component explanation below describes what this file's particular value on that component means in the rubric's framework.
No sensor, camera, or instrument backs this observation - it is testimony, relayed through the Department of War, and scored on the rubric's lowest sensor-quality tier for that reason. That doesn't bear on the witness's credibility (a separate axis); it reflects only that nothing beyond human perception recorded the event.
Reported by trained U.S. military personnel during an operational mission (12/17/1953) - a high witness-credibility tier, ranked in the rubric below astronaut, trained-aviator, and federal-agent testimony. This profile is shared across the AARO-submitted infrared-capture cluster that anchors the archive's densest scoring band, at 66.
On corroboration, this file from the Department of War - like every single-tier file in the PURSUE archive - is a single-witness or single-instrument capture per the released metadata. The rubric doesn't infer multi-witness confirmation the summaries don't actually establish; this score reflects the honest limit of what was released, not a judgment about the underlying event.
The released file contains no speed, acceleration, or vector data precise enough to score on the kinematic axis - and that's true archive-wide, not specific to this file. The rubric declines to infer kinematic anomaly from a witness's narrative estimate of how fast something moved; that itself says something about what PURSUE actually released: descriptive accounts, not flight-path telemetry.
Every file in the archive, including this one, scores this tier: a conventional explanation was considered in the released record but isn't treated as dispositive. That's a pattern in how war.gov's own summaries are written - they consistently hedge against strong conclusions either way - and the rubric takes that hedging at face value rather than resolving it for them.
This file was released as open by the Department of War after a formal review process concluded - not simply logged and left pending. That's a stronger disposition signal than 'unresolved, no review': a review actually happened, and remaining open is the Department of War's own published conclusion from it, not an absence of one.
Bottom line on the score: the Anomalousness Index of 56/100 reflects evidentiary weight that this specific file's encounter remains structurally unexplained by the rubric's six axes - it is not a claim that the underlying event involved anything non-conventional, and it is not comparable across rubrics that use different weights. For the full per-axis weights and the rubric JSON, see /methodology.
Related files in DoD
Other PURSUE files in the same category, ranked by Anomalousness Index.
DOW-UAP-PR024, Unresolved UAP Report, Middle East, 2023
DOW-UAP-PR072, "ADMINISTRATIVE REVISION: IIR 1777 J0032 22 Kazakhstan - UAP in the vicinit…
DOW-UAP-PR106, Unresolved UAP Report, Eastern United States, 2020
DOW-UAP-PR108, Unresolved UAP Report, Western United States, 2020
DOW-UAP-PR109, Unresolved UAP Report, Eastern United States, 2015
DOW-UAP-PR110, Unresolved UAP Report, Eastern United States, 2020
Verification
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