Document · February 1949
Unidentified Aerial Objects: Project “SIGN” (Air Materiel Command, Technical Report No. F-TR-2274-IA, February 1949)
Also known as Project Sign report, F-TR-2274-IA, Project SIGN report 1949
The report of Project Sign, the U.S. Air Force's first formal UFO study, prepared by the Technical Intelligence Division of Air Materiel Command at Wright-Patterson Air Force Base and released in February 1949. It summarises 243 domestic and 30 foreign reports, sorts the objects into four kinds, assesses what aerodynamics and propulsion they would need, and includes appendices by the astronomer J. Allen Hynek's Ohio State team, G. E. Valley of the Scientific Advisory Board and James Lipp of the Rand Project.
Its conclusions are cautious: no definite evidence either way, proof unlikely without the remains of a crashed object, many reports from reliable witnesses but none conclusive, and a recommendation to continue at a minimum level. Its appendices include an early official discussion of the idea that visitors might be drawn by atomic explosions, which the Rand study put at a thousand to one against. Our copy is the scan published on Wikimedia Commons, OCR'd for search; the OCR is imperfect.
Sources: Air Materiel Command, Project Sign report (1949)
Facts and claims
- documented The report states that Project “Sign” was initiated by the Technical Intelligence Division, Air Materiel Command, as project number XS-304 on 22 January 1948, under a letter from the Deputy Chief of Staff, Materiel, of 30 December 1947, subject “Flying Disks”, with Ohio State University analysing reports for astronomical causes and the Rand Project studying “the remote possibility that some of the observed objects may be space ships or satellite vehicles”. Source: doc-project-sign-report-1949.pdf
- documented Its results are “based on data derived from reports of 243 domestic and thirty (30) foreign incidents”. It sorts the objects into flying disks, torpedo or cigar shapes, spherical or balloon shapes, and balls of light. Source: doc-project-sign-report-1949.pdf
- documented Conclusions: “No definite and conclusive evidence is yet available that would prove or disprove the existence of these unidentified objects as real aircraft of unknown and unconventional configuration. It is unlikely that positive proof of their existence will be obtained without examination of the remains of crashed objects.” In this copy the word “without” is underlined by hand. Source: doc-project-sign-report-1949.pdf
- documented It adds that “Many sightings by qualified and apparently reliable witnesses have been reported”, but each has unsatisfactory features, and that “Based on experience with nuclear power plant research in this country, the existence on Earth of such engines of small enough size and weight to have powered the objects described is highly improbable.” Source: doc-project-sign-report-1949.pdf
- documented In an appendix, G. E. Valley of MIT, a member of the Air Force's Scientific Advisory Board, writes that if an extraterrestrial civilization exists, “Such a civilization might observe that on Earth we now have atomic bombs and are fast developing rockets. In view of the past history of mankind, they should be alarmed. We should, therefore, expect at this time above all to behold such visitations”, and that some relation should be expected between the times of A-bomb explosions and of the sightings. Source: doc-project-sign-report-1949.pdf
- documented In another appendix, James Lipp of the Rand Project examines visits from Mars or Venus, notes that the first objects were seen in the spring of 1947 after five atomic explosions, and concludes that space travel from elsewhere in the Solar System is “possible but very unlikely. Odds are at least a thousand-to-one against it.” The report itself judges that this solution is “extremely improbable” and will not be further explored unless other solutions are eliminated. Source: doc-project-sign-report-1949.pdf
Connected files
Programs
- Project Sign (produced by)
Documents
- Twining memo: AMC Opinion Concerning “Flying Discs” (follows) — Sign was set up after the September 1947 Air Materiel Command opinion signed by Twining
Mentioned in this file
- Wright-Patterson Air Force Base (Place)
- J. Allen Hynek (Person)
More documents
- GAO report on the Roswell crash records (B-262046, July 28, 1995)
- Hearing transcript: Symposium on Unidentified Flying Objects — House Committee on Science and Astronautics (July 29, 1968)
- Hearing transcript: Unidentified Flying Objects — House Armed Services Committee (April 5, 1966)
- Project Blue Book case file: Lincoln, New Hampshire, September 1961 (the Hill case)
- Transcript of a presentation by Captain Edward J. Ruppelt, March 1952 (DOW-UAP-D154)
- Hearing transcript: Department of the Air Force FY2025 budget request — House Armed Services Committee (April 17, 2024)
Links
- Wikimedia Commons — Project Sign report (PDF)
- Department of Defense FOIA reading room copy (archived)