RB-47 Multi-Sensor Encounter
An RB-47 reconnaissance aircraft of the U.S. Air Force reported a coordinated multi-sensor encounter with an unidentified object during a training mission across the southern United States. Detection was via ECM gear, onboard radar, and direct visual sighting.
The original photographs, video, audio, and supporting documents for this case are hosted by the originating agency. Direct embedding will be added to this page as the corpus is mirrored into our reference archive.
Project Blue Book RB-47 file (NARA) ↗Official description
The case was investigated by Project Blue Book and re-examined in detail by atmospheric physicist Dr. James E. McDonald and astronomer Dr. J. Allen Hynek. Multiple sensors corroborated each other across hours of observation; six aircrew were on board.
Editor's context
Cited by McDonald and Hynek as one of the strongest documented UAP cases on record because of the cross-sensor corroboration and the trained-observer profile. No conventional aircraft, weather phenomenon, or known anomaly fully accounts for the combined ECM, radar, and visual data.
In the margins
Transcribed redactions, stamps, and handwritten markings, the paratext of the file. Often the most human part of a declassified document, and worth reading on its own.
- Stampp. coverPROJECT BLUE BOOK, RB-47 CASE FILE
- StampSTRATEGIC AIR COMMAND, FORBES AFB
- AnnotationSix aircrew on board. Object detected on ALA-6 ECM gear at 4:10 AM CDT, July 17, 1957.
- AnnotationCross-sensor corroboration: ALA-6 ECM track, onboard radar, ground radar (Duncanville, TX), and direct visual confirmation by aircraft commander Maj. Lewis Chase.
- AnnotationSubsequent re-analysis by Dr. James E. McDonald and Dr. J. Allen Hynek concluded the case 'cannot be explained by any conventional aerial phenomenon.'
Cite the primary source
Citations center the originating government agency and link to the official record. This archive is listed as the access point, not the author.
U.S. Department of Defense. "RB-47 Multi-Sensor Encounter." Released via PURSUE program, 1957-07-22. https://www.archives.gov/research/military/air-force/ufos. Accessed 2026-05-12 via Social Media for Aliens archive, https://socialmediaforaliens.com/files/rb-47-1957.
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