Documents / Case file
This is an initial Project Sign progress report dated April 1948, sent from Headquarters, Air Materiel Command at Wright-Patterson Air Force Base to the Chief of Staff, U.S. Air Force. It tabulates about 100 unidentified flying object reports received through February 1948, covering shape, size, number of objects, speed and exhaust trails. Dr. Irving Langmuir found the data insufficient for a positive identification. Headquarters judged that a low aspect ratio aircraft using boundary layer control could reproduce many of the reported characteristics.
From the source:Release of 2026-07-10 Incident: 1948, Various. 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.”
• CONFIDENTIAL e Incident Ho. 25 26 27 28 29 30 ..' S0b 300 SI 32 33 33a B.xhaust Trail Heading Altitude Ft. Wot stated Bast High Bluish-black Not sta.ted Bot stated Bluish-black Not stated 10000 ft. 15 mi. long Not stated Not stated Not stated Not stated 10 flying High north; on reverse course there were only 7 None (ap- West 3000 peared to ha.ve bluish streaks out t'rom aides Five times 1200 Prom .,ery near length ot g?'Ound to 1000 object Small streak 8.8.Wo trailing object Wot stated Kot atated di!teNn.~ al• titudea ; White., heavy West to eut 20000-50000 ft. lone Stationary 3000 tt. lone lone visible Unknolm Jfone 210° from Extremely high Godman Field None Not stated Not stated Speed Effect on Clouds Fast Not stated llot stated Cut a clear path throup cloud• Fast Seemed to out 0loud1 open Did not moveo Seemed to go below horizon Bot stated with rotation of earth 300-400 mph Bot ate.ted Slow Bot stated 500 mph Jlot stated rt. a,tter 1t atartecl to le&"ff n.e1n1ty bceeding Bot ate.ted. 600 aph Jfotionlesa lot stated ~-~------ 600-~00 mph Bot 1ta1;ecl • • Stat1anary "lone nom n.aible Ione Stationary !lone Not stated Bot sta:t;edNND 927545
Case file, from the pursue collection. The PDF is mirrored here; the original link is above. 45 pages are in the text index: search them above, or from the library's search.