Technical Report "Unidentified Aerial Objects, Project SIGN," February 1949 — NARA Record Group 341

NARA Report landing 1940s Official link verified

Summary

AI-assisted summary — not an official document and not authoritative. It condenses the machine-extracted text; the original is the only authoritative source. Generated by summary:claude-opus-4-8@v1; last reviewed 2026-06-02.

The February 1949 U.S. Air Force technical report of Project Sign, the first organized U.S. military study of unidentified flying objects (begun 1948) and the predecessor of Projects Grudge and Blue Book. Held in National Archives Record Group 341.

Project Sign was the first organized U.S. Air Force study of unidentified flying objects, established in 1948. This record is its February 1949 technical report, "Unidentified Aerial Objects — Project SIGN," held in National Archives Record Group 341 (Records of Headquarters U.S. Air Force). Sign examined early postwar UFO reports and did not reach a single definitive public conclusion about their nature; the program was reorganized later in 1949 as Project Grudge, which in turn preceded Project Blue Book (1952–1969). The archive links to the National Archives Catalog entry for this report and does not host the document.

Common questions

What was Project Sign?
It was the first organized U.S. Air Force study of unidentified flying objects, established in 1948 and the predecessor of Projects Grudge and Blue Book.
What is this record?
It is Project Sign's February 1949 technical report, "Unidentified Aerial Objects — Project SIGN," held in National Archives Record Group 341.
What came after Project Sign?
Project Sign was reorganized as Project Grudge in 1949, which in turn preceded Project Blue Book (1952–1969).

Source & Classification

Record metadata

Record type
Report landing
Decade
1940s
Review status
published
Publication status
published

Official source link

https://catalog.archives.gov/id/461456722

Documents are linked to official source pages; copyright and license notes are recorded per source. This archive does not embed PDFs or videos.

Cite this record

National Archives and Records Administration (NARA). "Technical Report "Unidentified Aerial Objects, Project SIGN," February 1949 — NARA Record Group 341". 1940s. Official source: https://catalog.archives.gov/id/461456722. Cataloged by the independent UAP Records Archive (not an official or government source): https://uap-archive.org/uap/records/nara-rg341-project-sign-technical-report-1949/.

BibTeX

@misc{uaprecords_nara-rg341-project-sign-technical-report-1949,
  title  = {Technical Report "Unidentified Aerial Objects, Project SIGN," February 1949 — NARA Record Group 341},
  author = {National Archives and Records Administration (NARA)},
  year   = {1940s},
  howpublished = {Official source: https://catalog.archives.gov/id/461456722},
  note   = {Cataloged by the independent UAP Records Archive — not an official or government source},
  url    = {https://uap-archive.org/uap/records/nara-rg341-project-sign-technical-report-1949/}
}

Evidence

License note (source-level)

U.S. Government records (U.S. Air Force), generally public domain under 17 U.S.C. §105; held in NARA Record Group 341 (Records of Headquarters U.S. Air Force (Air Staff)). Referenced via the official National Archives Catalog entry only; not self-hosted by this archive.

Archivist note

This record is the February 1949 U.S. Air Force technical report titled “Unidentified Aerial Objects — Project SIGN.” Project Sign was the first organized U.S. Air Force study of UFO reports and a predecessor to Projects Grudge and Blue Book; the report is held in National Archives Record Group 341 (Records of Headquarters U.S. Air Force (Air Staff)). This archive links to the official National Archives Catalog entry and does not self-host the document.

Uncertainty / Limits

Archive state (this release)

Record status
Official link verified
Review status
published
Publication status
published
Archive URL
Not archived in U3
Local copy
Not stored in U3
Summary
Not published
Translation
Not published

U3 does not download or locally store source files.

Translation

Translation: not published in this release.

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