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.”
10 15 20 25 30 •Incident ObaerTer' s •oo Ocoupad.on Ka.neunra Weather Capt, United Airlines Straight-away horizontal flight lot stated ll 12 lS 14 16 17 18 19 21 22 23 24 26 27 28 29 30a Coast Guard Deputy Sheriff !lot stated Sot ste.ted Jot stated Mot stated Private pilot llot stated Farmer lot stated lot stated Wot stated !lot stated lot stated Not stated llecba.nic TWA Representative Lt Governor ffest Coe.st Pi lot. 7000 hrs. Ca.pt. USAF. Asst Operations Officer VHF/DJ' Operator Horizontal flight Mot stated Not stated FUppi ng around Not stated Hot stated Straight horizontal flight Horizontal fli ght Straight course - were flying about a city block apart. one behind the other Straight course Single file Flashing Horizontal flight Shooting up and down Hori&ontal flight lot atated llot stated lot stated Bot stated Climbing and descending ver- tioally Hovering, made three 3600 turns around one place. Moved to another position and circled more. Turns required 30-40 seo. Diaaeter estimated at 2 miles. Kot stated Not stated Bot stated Mot stated Iot stated Mot stated Clear as crystal Clear Cloudless and sunny lot stated Rot stated Bot stated •ot stated Clear Bright moonlight Not stated Clear Kot stated lot stated Solid overcast Overcast. 1000 ft.
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.