Project Sign Progress Report, 1948
🏛️ Department of War
This file contains an initial report from the Air Materiel Command regarding Project Sign. Project Sign was a 1948-1949 U.S. Air Force program to investigate the nature and origin of unidentified flying objects (UFO). The report details 100 UFO sightings from 1947-1948. The file also contains an article excerpted from “The Aeroplane,” an aviation-focused periodical magazine published between 1911 and 1968, titled “The Biology of the Flying Saucer.”
Key points
- 🏛️ Official U.S. government release — batch 4 (Jul 10, 2026)
- Official file: DOW-UAP-D097
- When: 1948
- Where: Various
📖 In the encyclopedia
Read it yourself
The description above is the government’s own, from the official release. The official file is linked on this page.
Department of War. (1948). Project Sign Progress Report, 1948. https://www.war.gov/medialink/ufo/071026/release_04/documents/DOW-UAP-D097_Project-Sign-Progress-Report_1948.pdfRelated records
Department of the Air Force Committee to Review Project Bluebook, 1966-1967
Department of War
This file documents the 1966-1967 deliberations and recommendations of the U.S. Air Force (USAF) Scientific Advisory Board’s Ad Hoc Committee to Review Project Blue Book. Project Blue Book was a 1952-1969 USAF program to investigate the nature and origin of unidentified flying objects (UFO). The Committee recommended that the USAF contract a scientific team composed of university-affiliated representatives to investigate selected UFO sightings. The USAF subsequently adopted the Committee’s recommendation.
Correspondence Relating to Project Blue Book, 1955
Department of War
This file contains correspondence relating to Project Blue Book, a 1952-1969 U.S. Air Force program to investigate the nature and origin of unidentified flying objects (UFO). The correspondence includes letters and memoranda sent between various departments and agencies of the U.S. Government, the Legislative Branch, and private citizens concerning UFO sightings and the research and findings of Project Blue Book.
Joint U.S.-Canadian Aviation Projects and UFO Sighting Reports, 1954-1955
Department of War
This file contains reports, memoranda, and correspondence concerning various then-developmental vertical take-off and landing (VTOL) aircraft. The file includes assessments of the experimental potential of the “Avro Project Y2,” a joint U.S.-Canadian near-circular VTOL aircraft that is similar in appearance to contemporary popular descriptions of unidentified flying objects (UFO). A 1954 memorandum opines that VTOL aircraft with a circular planform may be mistaken for UFOs to observers unfamiliar with such technologies. It also recommends that UFO reports in the vicinity of Soviet military operations or assets be re-examined to assess whether they may be attributable to previously unknown advanced VTOL aircraft of foreign design. The file also contains correspondence relating to a UFO incident involving a U.S. Air Force (USAF) KC-97 flying near Newfoundland, Canada in July 1955. A USAF committee found that the characteristics described in the report were inconsistent with those of known Soviet, American, or Canadian military systems. The committee was also “unable to explain the simultaneous ground radar returns and aircrew visual sightings.” It also contains correspondence relating to the potential value of data from incidental radar collection of meteors entering the atmosphere. USAF Air Research and Development Command recommended using that data to improve the performance of the AN/FPS-17 radar system. Finally, the file contains correspondence indicating support for the Communications Instructions for Reporting Vital Intelligence Sightings (CIRVIS) program, a joint U.S.-Canadian civil-military program to standardize reporting methods for unusual or unidentified airborne and maritime hazards and threats.
Analysis of Flying Object Incidents in the United States, 1949
Department of War
This file contains a U.S. Air Force (USAF) Air Intelligence Division study, “Analysis of Flying Object Incidents in the United States,” Study No. 203, dated 04/28/1949. The analysis includes an assessment of various reported unidentified flying object (UFO) incidents and theories to account for their nature and origin. Overall, the study assesses that “it appears that some object has been seen; however, the identification of that object cannot be readily accomplished.” The study offers that two “reasonable” origins might account for the phenomena: technologies of a domestic or foreign origin. It also suggests that, if foreign, it is prudent for the United States to assume that UFO observations are attributable to scientific, military, or intelligence activities of the Soviet Union, and, in that case, to take seriously the threat such objects may pose. The file also contains selected contemporary UFO reports and examples of experimental “flying wing” type aircraft planforms that might account for certain commonly reported UFO characteristics. AARO Comment: This file appears to be a later revision of the file contained in DOW-UAP-D093, whose content is substantively similar.