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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.

I
IGraphical Presentation
Graphical representation of the important information contained in Ithe tables is presented in Figures l through 38. These figures present the
distributions of the important variables only by the total nu.mber of cases Iin each identification category, since no significant differences were found
between the distributions of "Certain'' and "Doubtful" identifications of
objects with respect to the variables. A chronological study of these Ifigures will afford a broad picture of the tabulated information, without the
necessity of a detailed study of the tables.
IA critical examination of the figures will show that no trends, patterns,
or correlations are to be found, with the exception of Figures 18 through 30. IThe apparent similarity of the distributions shown by these mirror graphs,
Figures 18 through 23, was tested by statistical methods which showed that
there was a low probability- that the distributions of the KNOWNS, and IUNKNOWNS by these characteristics were the same. These tests and their
interpretation are discussed in the following section. For purposes of this Istudy, the strategic areas, shown in Figures 32 through 38, and Tables
A223 through A240, Appendix A, were designated on the basis of concen
tration of reports of OBJECT SIGHTINGS in an area. No other interpre Itation of the tables or remaining charts was deemed necessary.
IAdvanced Study of the Data
I
It was recognized that the lack of any patterns or trends, as shown by
the tabulations and graphs, provided an insecure basis for drawing definite Iconclusions. Accordingly, shortly before the sorting and tabulation pro
gram was concluded, a program of study of the data was developed to
utilize statistical and other mathematical methods, which could lead to a Imore concrete interpretation of the problem.
I
Position of the Sun Relative to the Observer
IThe first thing that was done was to calculate the angle of elevation of
the sun above the horizon and its bearing from true north as seen by the Iobserver at the time of each sighting. With this information, it could then
be determined whether there was a possibility that the reported object
could have been illuminated by light from the sun. In addition, it could be Idetermined whether an object could be a mock sun ( sun dog) or whether
there was a possibility of specular reflection from an aircraft at the posi
tion of the object, which would give the appearance of a "flying disc". I
A program of computation was set up and carried out to obtain the Iangle of elevation and the bearing of the sun for each sighting. All informa
tion needed for this calculation was available on the deck of IBM cards.
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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.