CIA Official Record Copy: Project Blue Book Special Report No. 14 — Analysis of Reports of Unidentified Aerial Objects (1955)

Source file: CIA-UAP-015-Project_Blue_Book_Special_Report_No_14.pdf Originating agency: Air Technical Intelligence Center (ATIC), Wright-Patterson Air Force Base, Ohio (held as CIA Official Record Copy) Document type: Special Report (Project No. 10073) Classification: FOR OFFICIAL USE ONLY (AFR 190-16) (Approved for Release 2026 under Section 1842 of the NDAA FY2024) Date: 5 May 1955 Total pages in CIA copy: 312 (cover, TOC, Summary, Introduction, key analytical sections, and Conclusions read) VIRIN: 260508-O-D0360-1092 PURSUE Release: 3

Summary

Project Blue Book Special Report No. 14 is the most comprehensive statistical study of UFO sightings ever produced by the United States government. Prepared by the Air Technical Intelligence Center (ATIC) at Wright-Patterson Air Force Base and dated 5 May 1955, it analyzed approximately 4,000 unidentified aerial object reports filed with the Air Force between June 1947 and December 1952 (with supplementary tracking of 1953-1954 cases). Data were reduced to IBM punched-card form and subjected to statistical analysis by a panel of consultants drawn from both military and civilian scientific fields.

The study is held in CIA records as an "Official Record Copy," with a CIA cover sheet and a handwritten note on the first page. A marginal annotation notes the document was reviewed by "RJ Warsh" on 11/21/94, with handwritten notes indicating clipped items were entered into computer. The CIA's official blurb states that, except for the handwritten note, the document's contents have previously been available on the CIA's public website; the release of this copy constitutes declassification of the CIA's own custodial record.

The report's central finding: it was "highly improbable" that any of the unidentified cases represented observations of technological developments outside the range of present-day scientific knowledge. However, the study found that approximately 22 percent of cases evaluated through 1952 remained UNKNOWN after full analysis — a fraction that the study acknowledged could not be explained away and that drove significant follow-on investigation.

Research Article

Origins and scope

The study began in 1953 following the unprecedented surge in UFO reports during 1952, which tripled the accumulated Air Force caseload. By the time analysis was complete, approximately 4,000 reports spanning June 1947 to December 1952 had been evaluated. Reports came from a cross-section of the US population: scientists, housewives, farmers, students, military personnel, and technically trained members of the armed forces. The study explicitly acknowledged that most reports were submitted by "serious people, mystified by what they had seen and motivated by patriotic responsibility."

The principal challenge was subjectivity. Sighting reports were impressions and interpretations rather than scientific measurements. To address this, ATIC developed a series of standardized questionnaires (three successive versions, the final being the US Air Force Technical Information Sheet) and a master coding plan for IBM punched-card data reduction. A Work Sheet (later the Card Bible) allowed simultaneous transcription by multiple workers. The CODES system, included as Exhibit B4 in the report, translated non-numerical observational data into numerical form.

Methodology

Three types of sighting categories were defined to support statistical analysis:

• ALL SIGHTINGS: one report per observer (including both single and multiple observers)
• UNIT SIGHTINGS: one report per sighting event
• OBJECT SIGHTINGS: one report per phenomenon (the assumed actual number of objects)

Evaluation of each report assigned it to one of ten identification categories: Balloon, Astronomical, Aircraft, Light Phenomenon, Birds, Clouds/Dust/etc., Insufficient Information, Psychological Manifestations, Unknown, or Other.

The analytical process involved three steps: deduction of discrete facts from subjective data; rating of the observer and report reliability; and determination of the probable identification of the observed phenomenon.

Key statistical findings

The 1953-1954 supplementary tracking (854 individual reports) produced the following classification breakdown:

• Balloons: 16%
• Aircraft: 20%
• Astronomical: 25%
• Other: 13%
• Insufficient Information: 17%
• Unknown: 9%

For the January-May 1955 period (131 reports received), the breakdown was:

• Balloons: 26%
• Aircraft: 21%
• Astronomical: 23%
• Other: 20%
• Insufficient Information: 7%
• Unknown: 3%

The trend across both periods showed decreasing UNKNOWN percentages as investigation procedures improved, particularly after the establishment of AF Reg. 200-2 (Subject: Unidentified Flying Objects Reporting, short title UFOB, dated 12 August 1954), which established the 4602d Air Intelligence Service Squadron (Air Defense Command) as the primary field investigation unit.

The "Flying Saucer" model analysis

A critical section of the report attempted to derive a verified model of a "flying saucer" from the 12 best UNKNOWN cases that contained descriptions detailed enough to permit diagrams. These 12 cases were categorized by shape: propeller (Case I), aircraft (Cases II-III), cigar (Cases IV-V), and elliptical or disc (Cases VI-XII).

The study concluded that no consistent model could be derived. Each of the 12 good UNKNOWN cases failed to satisfy at least one of four conditions required for model validity: that the shape fit many other UNKNOWNS, that the observer and report be reliable, that the report eliminate familiar explanations, and that the model be derivable from two or more non-conflicting good UNKNOWNS.

Case XII (Serial 3601.00) is among the most striking individual cases described: on the morning of August 25, 1952, a radio station musician driving to work stopped his car when he noticed an object hovering about 10 feet above a field. The object, described as approximately 75 feet long and 45 feet wide, shaped like two oval meat platters placed together with a dull aluminum surface, bore a row of small propellers around its outer edge and windows in its midsection, through one of which the head and shoulders of a motionless figure facing forward were visible. The object ascended vertically when the observer approached, and investigation of the area found some evidence of vegetation disturbance. Observer reliability was rated "good."

Conclusions

The report's formal conclusions are quoted verbatim in the document:

"It is emphasized that there was a complete lack of any valid evidence consisting of physical matter in any case of a reported unidentified aerial object."

"Thus, the probability that any of the UNKNOWNS considered in this study are 'flying saucers' is concluded to be extremely small, since the most complete and reliable reports from the present data, when isolated and studied, conclusively failed to reveal even a rough model, and since the data as a whole failed to reveal any marked patterns or trends."

"Therefore, on the basis of this evaluation of the information, it is considered to be highly improbable that any of the reports of unidentified aerial objects examined in this study represent observations of technological developments outside the range of present-day scientific knowledge."

The conclusions also acknowledged a psychological dimension: repeated reading of UFO reports produced a saturation effect among the study personnel, replacing initial fascination with skepticism, and the authors warned that popular books and articles cited only "more lurid-sounding reports," creating a false impression of the overall dataset.

The CIA's custodial record

The value of this document in the PURSUE release lies partly in the CIA's possession of it as an "Official Record Copy." This confirms CIA interest in and retention of the most significant Air Force UFO statistical analysis — consistent with the agency's parallel ongoing investigations and its coordination with ATIC during this period. The handwritten note on the first page and the 1994 review annotation suggest the document remained in active CIA records use for decades after its production.

Key People

Locations

Incidents

Notable Quotes

"Reports of unidentified aerial objects (popularly termed 'flying saucers' or 'flying discs') have been received by the U.S. Air Force since mid-1947 from many and diverse sources. Although there was no evidence that the unexplained reports of unidentified objects constituted a threat to the security of the U.S., the Air Force determined that all reports of unidentified aerial objects should be investigated and evaluated to determine if 'flying saucers' represented technological developments not known to this country." — Summary, page vii

"It must be emphasized, again and again, that any conclusions contained in this report are based NOT on facts, but on what many observers thought and estimated the true facts to be." — Origin and Nature of Data, page 3

"It is emphasized that there was a complete lack of any valid evidence consisting of physical matter in any case of a reported unidentified aerial object." — Conclusions, page 94

"Therefore, on the basis of this evaluation of the information, it is considered to be highly improbable that any of the reports of unidentified aerial objects examined in this study represent observations of technological developments outside the range of present-day scientific knowledge." — Conclusions, page 94

"It is a definite fact that upon reading a few reports, the reader becomes convinced that 'flying saucers' are real and are some form of sinister contrivance. This reaction is independent of the training of the reader or of his attitude toward the problem prior to the initial contact." — Flying Saucer Model section, page 93