FILE 037 // PUBLIC RECORD
Project GRUDGE
The Air Force UFO investigation that followed Project SIGN and preceded Project BLUE BOOK.
DOCUMENTATION CONFIDENCE
ModerateOfficial records document the subject, but the available material contains unresolved questions, contested interpretations, incomplete data, or a limited number of primary sources.
CASE OVERVIEW
Project GRUDGE: What the public record documents
GRUDGE evaluated reports with a more skeptical institutional posture and attributed most cases to conventional causes, hoaxes or psychological factors.
EXECUTIVE SUMMARY
The public record identifies Project GRUDGE as a ufo / uap matter associated with U.S. Air Force during 1949–1951. The Air Force UFO investigation that followed Project SIGN and preceded Project BLUE BOOK.
GRUDGE evaluated reports with a more skeptical institutional posture and attributed most cases to conventional causes, hoaxes or psychological factors.
The program illustrates changing official attitudes toward UFO reports. Its conclusions did not end public interest, and renewed reporting led to the creation of Project BLUE BOOK.
The linked source set contains 1 official or primary archival record. Together, these materials establish the responsible organizations, the relevant time period, the reported location, and the official findings or historical conclusions summarized in this file.
Where the underlying records contain allegations, witness statements, preliminary leads, or unresolved observations, this archive identifies them as claims or unresolved material rather than established fact. The appearance of a statement in a government file does not by itself prove that the statement is accurate.
KEY FINDINGS
Documented time period: 1949–1951.
Primary organizations or record holders: U.S. Air Force.
Principal location: Wright-Patterson Air Force Base, Ohio.
Archive topic: UFO / UAP.
Major public release or publication year: 1951.
DOCUMENT ANALYSIS
National Archives — Project BLUE BOOK and predecessor records
Official archival or primary-source recordEstablishes archival provenance, release history, and the official record collection available to the public.
OPEN DOCUMENT ↗SOURCE DOCUMENTS
National Archives — Project BLUE BOOK and predecessor recordsOfficial or primary archival source used to document this file.OPEN SOURCE ↗