Documents / Case file
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 ISINGLE OBSERVATION - A SIGHTING consisting of a single report from ( 1) one OBSERVER with no knowledge of additional OBSERVERS of the same phenom Ienon, or (2) a group of witnesses of the same phenomenon, each cognizant of the others. The witness who made the report is called a SINGLE IOBSERVER. IMULTIPLE OBSERVATION - A SIGHTING consisting of several reports from OBSERVERS of the same phenomenon who were cognizant of each other. IThe witnesses who made reports are called MULTIPLE OBSERVERS. I ALL SIGHTINGS - ( 1) The group of reports consisting of one report for each OBSERVER, including both ISINGLE and MULTIPLE OBSERVERS. (2) The questionnaire, work sheet, and IBM card representing the report from each OBSERVER - Iin other words, the representation of each report accepted for the statistical study. I UNIT SIGHTINGS - ( 1) The group of reports consisting of one report for each SIGHTING, including all the Ireports of SINGLE OBSERVATIONS and the one most representative report from each MULTIPLE OBSERVATION. (2) The questionnaire, work Isheet, and IBM card representing the report for each SIGHTING accepted for the statistical study. I A major serial number (four digits) was assigned to each sighting, segregating the year of occurrence by selection of limits for each year, as Ifollows: I0001 to 0500 reserved for 1947 0501 to 1000 reserved for 1948 1001 to 1500 reserved for 1949 I150lto2000 reserved for 1950 2001 to 2500 reserved for 1951 2501 to4900 reserved for 1952 I While this scheme would serve to identify any individual sighting, identifi Ication of each report and its subsequent forms was necessary. The minor subserial numbers ( two digits) fulfiiled this requirement. For all SINGLE OBSERVATIONS, a major serial number followed by two (2) zeros, for Iexample, 2759. 00, was sufficient identification. For MULTIPLE OBSER VATIONS, the major serial number followed by a series of two-digit num bers ranging from 00 to 99 was used to identify the individual reports. In Igeneral, the most complete report from the most reliable observer of that I8 I
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.