DOW-UAP-D163: Swedish aircrew account and investigation
A January 1954 U.S. air attaché report translates press coverage of Transair pilot Ulf Christiernsson and crew chief Olle Johansson’s brief sighting near Hässleholm, Sweden. It records their description of a shining, nearly round object and an ongoing Swedish investigation. The file also includes an unnamed acquaintance’s adverse credibility assessment, which remains attributed testimony rather than an established fact about the pilot.
- File
- Document · Release 07
- Date
- Dec 17, 1953
- Location
- Sweden
- Extent
- 3 pages
Search This File
Probed Assessment
The file records a brief aircrew report and an unfinished investigation, with estimated performance and disputed witness credibility.
Key takeaways
- The encounter is conveyed primarily through translated newspaper reporting.
- Speed and range are estimates, not instrument readings.
- Radar inquiries are mentioned without their results.
- Adverse claims about the pilot come from an unnamed acquaintance.
Why it matters
The source layers and unresolved investigation matter as much as the reported appearance.
Corroboration
Two crew members are named, but the released file provides neither raw radar data nor an independent identification.
Open questions
- • What did the Swedish radar inquiry find?
- • Are the original crew statements and investigation conclusions available?
Probed separates this editorial assessment from the source claims below. It summarizes what the released artifact supports; it is not independent verification.
Official Description from War.gov
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.
Preserved verbatim as source metadata. This wording is separate from Probed’s file-specific description and assessment.
File Context
Related entities
Tracker findings
Swedish flight crew supplied the press account
The translated report identifies Transair pilot Ulf Christiernsson and crew chief Olle Johansson as observing an object from their DC-3 at 1437.
Speed and altitude were pilot estimates
Christiernsson estimated the object’s speed at about the speed of sound and its position about 600 meters below his aircraft; these are pilot estimates.
Pilots described an elliptical appearance from below
Christiernsson described a narrow initial silhouette that appeared nearly round and slightly elliptical as it passed below; he reported no exhaust or condensation trail.
The file does not confirm a corresponding radar return
A quoted statement by General Nordenskiöld says investigators were checking what radar stations might have observed; the file supplies no resulting radar confirmation.
The report called for further investigation
Despite those attributed doubts, the report says press accounts described an ongoing Defence Staff investigation and that the attaché office was seeking more information.
Release provenance
- Release
- Release 07
- Official ID
- release-07-file-016-dow-uap-d163-air-intelligence-information-report-sweden-1953
- Cleared
- Oct 23, 2026
Referenced Timeline
Transair crew reports object near Hässleholm
The translated press account places the encounter at 1437 during a Bulltofta–Bromma flight.
Air attaché forwards report and reservations
Rowen’s report distinguishes press reporting from an unnamed acquaintance’s adverse assessment.
Source Claims
Claims are attributed to the released source and remain distinct from Probed’s assessment and tracker findings.
Burt Rowen’s January 13, 1954 report forwards a translated newspaper account of the December 17, 1953 sighting near Hässleholm.
Included is a translation of Captain Christiernsson's description of the incident, as reported in an interview with the local press.
The translated report identifies Transair pilot Ulf Christiernsson and crew chief Olle Johansson as observing an object from their DC-3 at 1437.
Capt. Ulf Christiernsson, and his crew chief, Olle Johansson
Christiernsson estimated the object’s speed at about the speed of sound and its position about 600 meters below his aircraft; these are pilot estimates.
at what I would say was the speed of sound
The reported observation lasted six or seven seconds as the object traveled in the opposite direction and disappeared southwestward.
It was going in a southwesterly direction and disappeared after six or seven seconds.
Christiernsson described a narrow initial silhouette that appeared nearly round and slightly elliptical as it passed below; he reported no exhaust or condensation trail.
I saw that it was nearly round, just slightly elliptical.
The translated Defence Staff communiqué says it knew of no Swedish aircraft in that area at the relevant time and was investigating.
The De- fense Staff does not know o.f any Swedish plane that was in that area at the time in question.
A quoted statement by General Nordenskiöld says investigators were checking what radar stations might have observed; the file supplies no resulting radar confirmation.
what our radar stations might have spotted.
The attaché report attributes doubts about Christiernsson’s credibility to an unnamed lifelong acquaintance in the Royal Swedish Air Board; it does not independently substantiate that assessment.
the source above personally doubts Christiernsson’s story
Despite those attributed doubts, the report says press accounts described an ongoing Defence Staff investigation and that the attaché office was seeking more information.
This office is attempting to obtain further information on the occurrence.
Source Material & Evidence
Research Map
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