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CIA-UAP-015, Project Blue Book Special Report No. 14 (Analysis of Reports of Unidentified Aerial Objects)

Central Intelligence Agency · 312 pages · text from the file's own layer

This CIA archives copy, released in 2026, holds Project Blue Book Special Report No. 14 (Analysis of Reports of Unidentified Aerial Objects). The Air Technical Intelligence Center at Wright-Patterson Air Force Base issued it on 5 May 1955. The study reduced about 4,000 sighting reports from 1947 to 1952 to IBM punched cards, with 3,201 cases charted, and applied chi square tests to compare known and unknown sightings. It concludes that it is highly improbable the reports represent technological developments beyond present-day scientific knowledge.

From the source:Release of 2026-06-12 This is the USAF Project Blue Book with a CIA cover sheet stating the document is "Official Record Copy." With the exception of the handwritten note on the first page, the content of this document has been available on CIA's public website.

  • p. 96 …approach the speed of a jet before it disappeared. No propulsion was apparent. Time of observation…
I
I
I UNKNOWNS with sufficiently detailed description would be called II good
UNKNOWNS", while the remainder would simply be called UNKNOWNS.
One hundred sixty-four folders of a total of 186 OBJECT SIGHTINGS in
I Groups 1, 2, 3, 6, and 7 were examined. There were 18 possible aircraft,
20 possible balloons, 7 good UNKNOWNS, 100 UNKNOWNS, and 19 others
which were identified as being possible KNOWNS of various types. It is
interesting to note that two of these were established as mock suns on the
I basis of the angle of sun elevation and the sun bearing angle, together with
the direction of the object from the observer. In addition, the UNKNOWNS
I in angle-of-sun-elevation Groups 4 and 5 (nighttime sightings) were scanned
with no attempt at identification, but to find any possible "good UNKNOWNS".
There were five sightings that could be put into this category.
I
I Of the UNKNOWNS, there were approximately 20 sightings that were
observed in such a way that they should have been recognized easily if they
had been familiar objects, that is, there was little possibility that their
shapes, as seen, could have been distorted sufficiently by one cause or
I another to render them unrecognizable. There were a very few that would
have been identified as guided missiles or rockets, but that were not so
identified because of the geographical location in which they were seen.
I
I All of the remaining UNKNOWNS were classified as such solely be
cause they were reported to have performed maneuvers that could not be
ascribed to any known objects. In these cases, the shape might have been
unrecognizable also, but it was felt that this was because of distortion and
I distance, or because of darkness.
This is a very important point. To put it differently, if these
I UNKNOWNS, which represent all but about 40 of the UNKNOWN SIGHTINGS,
were reported to have performed maneuvers which could be ascribed to
I known phenomena, they would pro~ have been identified as KNOWNS.
With the exception of some radar sightings, all of these maneuvers were
observed visually. The possibilities for inaccuracies are great because
I of the inability of an observer to estimate visually size, distance, and
speed.
I Reports of sightings by radar usually were of high-speed objects,
some at extremely high altitudes. Some were identified as UNKNOWNS
I because there was no object to be seen visually at the point indicated by the
radar set. It cannot be said with any assurance what these radar sightings
mean, but the most logical explanation is that they are ground targets re
I flected by an atmospheric temperature inversion layer. The validity of this
I statement cannot be established. It is felt that radar sightings in this study
are of no significance whatsoever unless a visual sighting of the object also
1s made.
I Taken in conjunction with the Chi Square Tests discussed earlier,
I
the results of the re-evaluation of reports identified as UNKNOWN
SIGHTINGS would seem to indicate that the majority of them could easily
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Cases discussed

About this file

Case file, from the pursue collection. The PDF is mirrored here; the original link is above. 312 pages are in the text index: search them above, or from the library's search.