DOW-UAP-D100, Air Materiel Command Report on Unidentified Flying Objects, 1947-1948
This file is a collection of U.S. Government memoranda and correspondence relating to “Project Sign,” a 1948 U.S. Air Force program to investigate reports of high-performance airborne objects. The documents characterize some of these reports as being consistent with “real” objects rather than fabrications or resulting from perceptual errors. The U.S. Air Force cites the reported characteristics of the phenomena, e.g., high speed and maneuverability, as exceeding known performance envelopes of U.S. military aircraft and thereby presenting a potential national security threat, if validated. This potential threat prompted the Air Force to call on the Air Materiel Command (AMC), the Service’s Major Command for logistics and procurement from 1946 to 1961, to gather further evidence to assess the validity of the reports. The Air Force emphasized that there was an “imperative need” for such evidence to enable appropriate countermeasures. The stated urgency of this request reflects the strategic environment of the early Cold War, a period characterized by heightened national defense concerns amid rapid global advancements in aerospace design and development. In framing the call for an investigation, the Air Force noted that sustained public interest and persistent inquiries from the press may eventually require an official statement in response. AMC’s investigation found that observers were generally not mistaken when reporting that they had seen an airborne object, but that their characterizations of those objects as unusual was likely a reflection of the “limits of their personal experience.” It identified “a great many” of the objects reported with a rounded appearance as “weather or upper air scientific balloons of some type.” It also identified several cases in which the reported objects were most likely celestial phenomena, such as Venus. AMC found that a small number of reports lacked a “reasonable everyday explanation,” but that “so far, no physical evidence of the existence of the unidentified sightings has been obtained.” AMC expressly considered whether the phenomena may have been “vehicles from another planet,” but found no evidence supporting such an origin. Ultimately, AMC found that “there is as yet no conclusive proof that unidentified flying objects, other than those which are known to be balloons, are real aircraft.” In light of these findings, AMC recommended that the Department of War should avoid publicly commenting on the subject of “flying discs.” Responding to the Air Force’s anticipated concerns regarding public interest in the subject, AMC recommended that the Department should reply in terms that minimize the investigation’s inconclusive findings, focusing on positive determinations in cases assessed to be weather balloons and celestial phenomena.
The summary above is sourced from the released file metadata as published to war.gov. The analysis sections below are original to this tracker.
Text of the document
Machine-extracted from the PDF war.gov published (its text layer or OCR), so expect errors, especially in names, numbers and handwriting; the PDF is the authoritative copy. Lines that did not extract as readable text are left out. Showing about 995 words from pages 1, 2, 3, 5, 7 of 245.
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SUBJECT, Vlying Object Inoid•nta in the United Statea !Os Cc=m.nding General. Air Materiel Command Wright-Patteracc Air Force Bo.ee Dayton. Chio l. By lettcr'datcd 30 Decembor 1947 from the Director of Research and Development,, Headqunrters USAF, your Ileadquartora flying object has been obecrved. I.dontification a.nd the origin or these objects is not diaoernibl~ to this Headquarters. It ia imperat1vo. therefore, that otforte to detennine whether theae object• are or doiaoatic or fore1511 or1i1n must be increaaod until oonolusive evidonoo 1c ,obtained. The needs or national defense require euch evidence 1n order that appropriate countermeaaurea 5. In addition to the imperative nood !'or evldenoe to perm1t oountermasures, ia tho nooosoity ot in:l.'orcdnc the public as to the ato.tus of t:he problem. To de.tc thorc hao boen too 1 ittlo do.ta to present to the public. The pre••• however, h about to take it into its own hands Md der.and to be told what wo do or do not know about the e1tuntion. Silence on our part will not long bo ccoopt 4. Request imnediate information as to your conclusions to date and your reoo=cendations a.a to tha information to be giTen to the preea • Your recamnendat1 on is requestod ala o '18 to whether thn.t infornation ahould be offered to tho press or with hold until it i s actively sought by the press. BY COlWAlm CF THE CHIEF OP S1'.AFF1
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SUBJECT, Flying Objeot Incident• in the United State• TO, Co ndin Gen ral, Air toriel Co D yton, Olio l. By letter dated 30 December 1947 tro the Director of Research and Development, Headquartera USAF, your Headquart ra waa required to eat bliah Project 'SIGN". - ' 2. The conolu ion pp are ineaoapabl'e that e typo of flying objeot baa been oba rved. Identifio :tion nd the origin ot theae objects ia not discernible to this Headqu rtera. It ia imperativo, therefore, that ei't'orta to determine wh ther these objects are or om etic or foreign origin uat be increaa d until conolu ive e ideno ie obtained. The need• or national defense require auoh evidence 1n ordor that appropriate countermeaaurea :y bo taken. 3. In addition to the imperative need for evidence to permit counter aaur 1, ia t oeaaity of informing the public aa to the stat • or the problem. To dat ther ha. be n too little data to presen to th publio. The pres , awever, ia •bout o t ke it illto its n hand and dei:and to be told •hat we do or do not know bout th aituation. Silence our p rt will not long be accept ,. Request diate info tion aa to your concl udona to date and your r co ondationa as to the infor tion to be iv n to the pres. Your recommsndation is requested lao as to whether that infor ation ahould be orrero to the pr 11 or with hel9 until it ii actively sought by the pr as. BY CO OF THI CHI F OP STAFFi lajor Oe:oeral, USAI Oftloe of Director o t Stat! OperatioDS
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DEPARTMENT OF THE AIR FORCE HEADQUARTERS UNITED STATES AIR FORCE SU ..,..,CT: Flylne; Object Incidents ir. the 'Jnitod Sio.tes Du. ton, C,hio cone uo·vo videnco i ... obt ined. 71e needs of national dofenso ro 1uire ouch evidonco i."l order that appropr· to oounterneo.sures int., •to o,, h nds unu de .:i.nd to be iolu , ut uo tlo or do rot know lfajor C..iuc- al, USU Director of Intolligenoo. Ottice ot Deputy Cbiet ot Sta.ft, OperatiODS
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C-OVER 'SHEET a. ' RECORD OF BASIC CORRESPONDENCE OR REQUEST FROM: DATE: ASGD BY ________ DATE RECEIVED DIR/INT NO. c. SPECIAL INSTRUCTIONS - REMARKS (Use other side this sheet for additional remarks) d. TO BR. TO TO DIV. TO TO DIR/ INT TO DOWN UP DOWN UP DOWN UP 0 IP-FL AFOIP ASST EXEC 0 IR-CO ASST EXEC OIR-AA AFOIR OAI-AE AFOA I DISPATCHED BY ~ TO e.C--
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the United States" Hq AMC, Wright-Patterson Air Force Base, Dayton, Ohio. 8 Nov 48 TO, Chief of Staff, United States Air Force, Washington 25, D. ATTNs 1. In attempting to arrive at conclusions as to the mture of uniden tified .flying object incidents in the United States, this Command ha.a me.de a study of approximately 180 such incidents. Data derived from initial re ports have been supplemented by.further information obtained from check lists submitted by mail, from interrogations of other field agencies, and by personal investigation by personnel of this Command in the case of in cidents that seem to indicate the possibility of obtaining particularly significant information. 2. The objects described fall into the following general classifica tion groups, according to shape or physical configuration, a. Flat disc of circular or approximately o:l.rcular shape. b. Torpedo or cigar shaped aircraft, with no wings or fins visible in flight. c. Spherical or balloon shaped objects. d. Balls of light with no apparent form attached. 3. Some of the objects sighted have definitely been identified, upon further investigation, as weather or upper air scientific balloons of some type. A. great many of the round or balloon shaped objects indicated in paragraph 2c above are probably of the same nature, although in most cases, definite confirmation of that fact has been impossible to obtain. 4. Some of the objects have been identified as beiilg astro-physical in nature. For example, in daylight sightings, the planet Venus has been reported as a round, silvery object at extremely high altitude. Action is being taken to obtain the services of a prominent astro-physicist as a oon• sultant, to study all of the incidents to determine l'lhether some can be identified as meteors, planets or other manifestations of astral bodies. Arrangements for accomplishing a study of the psychological problans involved in this project are being made in coordination with the Aero-Medical Laboratory at this Headquarters. The possibility that some of the sightings are halluoir:a tions, optical illusions or even deliberate hoaxes has been con-
Where this file fits in the PURSUE archive
This file is one of DoD's 257 files in the Trump PURSUE disclosure. Within the DoD agency block it ranks #157 of 257 by Anomalousness Index. Across the entire 450-file archive it ranks #281 of 450.
That places it in the lower-scoring band of the archive (281 of 450 by score), typical of investigative-record style files where the report is paper-based rather than instrumented.
Anomalousness Index: 56/100
Evidentiary weight that this encounter remains unexplained after conventional analysis. Not a probability of extraterrestrial origin - that number is not honestly computable from the released files and this tracker refuses to publish it.
🤖 AI-ASSISTED SCORING · methodology
The six rubric components break down for this file as follows. Each component has a weighted contribution to the final score; the per-component explanation below describes what this file's particular value on that component means in the rubric's framework.
Reported by a witness with no instrumented record. The lowest tier in the rubric's sensor axis. Eyewitness perception in field conditions, even when the witness is highly credentialed, scores below capture by any instrumented modality. This report reached the federal record through the Department of War.
Trained U.S. military personnel reporting from an operational mission context. A high witness-credibility tier, ranked in the rubric below astronaut, trained-aviator, and federal-agent testimony. This is the witness profile shared by the entire AARO-submitted infrared-capture cluster that anchors the 66-point score band.
Single-witness or single-instrument capture. This is the corroboration tier for the overwhelming majority of the PURSUE archive on the released metadata - the rubric records the honest limit of the underlying record rather than inferring multi-witness corroboration that the released summaries do not establish. A small number of files with an independent second witness or instrument score on the multi-witness/multi-instrument tier above this one.
No kinematic measurements - speed, acceleration, vector - are published in the released file with sufficient precision to score on the kinematic axis. The rubric does not infer kinematic anomaly from narrative observer estimates. Every file in the archive carries this value, which is itself an observation about the disclosure: kinematic-grade telemetry was not part of what was released.
A conventional candidate explanation has been considered but is not dispositive. Every file in the archive scores this way - reflecting that the underlying release metadata systematically caveats strong determinations in either direction. The released summaries warn against reading them as conclusive analytical judgments, and the rubric respects that.
Released as open after formal review by the originating agency. The file passed through a review process and was published in that posture - a stronger disposition signal than 'unresolved with no review,' because review has occurred and the open status is the agency's published conclusion.
Bottom line on the score: the Anomalousness Index of 56/100 reflects evidentiary weight that this specific file's encounter remains structurally unexplained by the rubric's six axes - it is not a claim that the underlying event involved anything non-conventional, and it is not comparable across rubrics that use different weights. For the full per-axis weights and the rubric JSON, see /methodology.
Related files in DoD
Other PURSUE files in the same category, ranked by Anomalousness Index.
DOW-UAP-PR024, Unresolved UAP Report, Middle East, 2023
DOW-UAP-PR072, "ADMINISTRATIVE REVISION: IIR 1777 J0032 22 Kazakhstan - UAP in the vicinit…
DOW-UAP-PR106, Unresolved UAP Report, Eastern United States, 2020
DOW-UAP-PR108, Unresolved UAP Report, Western United States, 2020
DOW-UAP-PR109, Unresolved UAP Report, Eastern United States, 2015
DOW-UAP-PR110, Unresolved UAP Report, Eastern United States, 2020
Verification
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