Project Sign usually turns up attached to a story about a bold conclusion that got shelved. The archive here holds plainer material. Two Sign files cover most of 1948 from the Air Force side of the desk: DOW-UAP-D097, the progress report the Air Materiel Command sent to Washington in the spring, and DOW-UAP-D100, a bundle of letters from the autumn, when headquarters started asking for answers and the command had to say what it actually had. Neither file mentions the legend. (The step before Sign is the Twining memo of 1947.)
The spring report, DOW-UAP-D097
The first paragraph dates everything. It calls itself "an initial report on unidentified flying objects as directed by Hq, USAF letter dated 30 December 1947, signed by General L. C. Craigie." Quarterly reports were to follow from 1 July 1948. Paragraph two gives the machinery: a project activated on 26 January 1948, and Technical Instruction 2185, dated 11 February 1948. The extracted text carries a date of 23 April 1948 for the report itself.
Paragraph three is the one I keep coming back to. Before any theory, somebody at the headquarters secured the schedules of "lighted night-flying advertising blimps" and cross-checked them as a possible source of incident reports. It is the first piece of actual checking the report describes.
Then a short list of what the memo calls "interesting observations" from the case files:
- A "high rate of climb," plus an apparent ability to "remain motionless or hover for a considerable length of time."
- Objects described as oval, disc or saucer shaped. The count does not survive text extraction.
- Associated sound reported only a handful of times. The figure comes through as 11.
- Sizes from a coin up to a couple of hundred feet across, and from "a pursuit plane" to "the bulk of six B-29 airplanes."
- 77 sightings of a single object, with 21 and 8 in the two larger groupings.
- "Exhaust trails were reported 23 times."
- Speed estimated "throughout the entire range from very slow or hovering to supersonic."
Hovering and supersonic, same list, no attempt to reconcile them. Possibly the most honest line in the file.
Paragraph seven is the only outside consultation. Representatives visited Dr. Irving Langmuir at the General Electric research laboratories in Schenectady. His opinion, as recorded: "present available data does not encompass sufficient information to enable a positive identification to be made," and he "was reluctant to consider the so-called 'flying discs' as a reality."
The command's own view follows immediately, and it is an engineering view. Headquarters believed it "possible to construct a low aspect ratio aircraft that would duplicate many of the appearance and performance characteristics of reported 'flying discs'," and "experts have agreed that this would be possible through the intelligent application of boundary layer control." Colonel H. M. McCoy signs for the commanding general as Chief of Intelligence.
The 100-incident tabulation
Inclosure 1 is a tabulation of all available reports through 1 February 1948, numbered to 100 with lettered sub-entries. Most of the dates are June and July 1947. The first rows are Muroc Air Field in California, then a run of Portland, Oregon.
The occupations column is the best part. Air Force ranks from private first class to colonel, Portland police patrolmen, a United Airlines captain, a lieutenant governor, a judge, a farmer, a sign painter, an astronomer, an insurance adjuster, a colonel of the Kentucky State Police, and one entry that just reads "Hungarian Peasants."
The maneuvers column has the prose. A prospector's object was "standing on edge and banking in the clouds." A trout farm operator watched one that "rode up and down over the hills and hollow of the canyon floor." Another entry has discs that "would oscillate and sometimes a full disc would be visible, then a half-moon shape, then nothing at all." Most rows say "Not stated," which is also information.
After the table comes a notes page, and the command was grading its witnesses too. For Incident 18, it says the photograph and story were definitely determined to be a hoax carried out for publicity and money. For Incident 8, the person reporting was judged excitable, very talkative, possessed of an exaggerated imagination, and inclined to impress people with continuous chatter.
The Phoenix photographs and the Aeroplane article
The cover memo says inclosures 2 and 3 are enlargements of photographs from Incident 40, which the tabulation logs as 7 July 1947 in Phoenix, Arizona, one object, seen from the ground. Inclosure 4 is the headquarters evaluation, dated 19 February 1948, of the film forwarded for examination. It concludes the image is photographic in nature and not due to imperfections in the emulsion or a lack of development, and notes the report put the object at approximately 2,000 feet.
The memo invites attention to the "marked similarity" between the photos and inclosure 6, the last on the list. That is a magazine piece: "The Biology of the Flying Saucer," subtitled "The Story of Low Aspect Ratio Aircraft," by A. R. Weyl, from The Aeroplane of February 13, 1948. Its opening is drier than anything in the government pages: flying saucers had "ceased to be news. Presumably, they have all landed."
Inclosure 5, just before it, is listed as "Horten Parabola." That word comes back later.
November: headquarters wants answers, DOW-UAP-D100
The autumn file opens with a letter from Major General C. P. Cabell, Director of Intelligence, dated 3 November 1948, to the commanding general of the Air Materiel Command. It points back to the same 30 December 1947 letter that set up Project "SIGN," then gets blunt:
"The conclusion appears inescapable that some type of flying object has been observed. Identification and the origin of these objects is not discernible to this Headquarters."
The pressure is partly public. "The press, however, is about to take it into its own hands and demand to be told what we do or do not know about the situation. Silence on our part will not long be acceptable." Cabell asks for conclusions to date and a recommendation on whether information should be offered to the press or "withheld until it is actively sought by the press."
The reply is a first indorsement from AMC, dated 8 November 1948 and signed by McCoy, now Chief of the Intelligence Department. The count has grown to "approximately 180 such incidents," supplemented by "check lists submitted by mail," interrogations of other field agencies, and personal investigation. The objects fall into four groups: flat discs, torpedo or cigar shapes "with no wings or fins visible in flight," spherical or balloon shapes, and "balls of light with no apparent form attached."
Some of it is resolved. A great many of the round objects are probably weather or upper air balloons. In daylight sightings, Venus "has been reported as a round, silvery object at extremely high altitude." Hallucinations, optical illusions and "even deliberate hoaxes" have been considered.
Then the residue: "there remains a certain number of reports for which no reasonable everyday explanation is available. So far, no physical evidence of the existence of the unidentified sightings has been obtained."
Langmuir appears again, and his position reads a little differently in the retelling. The November letter says that in an early interview he "indicated that these incidents could be explained, but insufficient data were available." A second interview is planned, in the hope he will offer an opinion on the "balls of light."
The rest, briefly:
- All available information "indicates that the discs, the cigar shaped objects, and the 'balls of light' are not of domestic origin." Disc or wingless aircraft could fly, but would have "relatively poor climb, altitude and range characteristics" on the power plants of the day.
- "The possibility that the reported objects are vehicles from another planet has not been ignored," but tangible evidence is "completely lacking." Incidents were plotted against the approaches of Mercury, Venus and Mars, and a periodic variation turned up that "may be purely a coincidence."
- Paragraph nine cites "The Books of Charles Fort," the 1941 Henry Holt edition, and observes that similar phenomena "have been noted and reported for the past century or more." An Air Force intelligence letter footnoting Charles Fort. I did not expect that.
The conclusions are careful. Observers mostly saw some flying object they could not classify as an aircraft "within the limits of their personal experiences." There is "as yet no conclusive proof that unidentified flying objects, other than those which are known to be balloons, are real aircraft." Their nature cannot be established until physical evidence, "such as that which would result from a crash," is obtained.
On the press, the advice is to say nothing about what cannot be identified, and if reporters insist, to tell them many objects "have been identified as weather balloons or astral bodies."
October: the CIA, Rand, and the airlines
The same file holds the paperwork from the weeks before. On 7 October 1948, McCoy wrote to the Central Intelligence Agency, routed through Air Force headquarters, asking for any evidence that the objects were of domestic origin. The closing line: "Your cooperation in so doing might greatly assist in identifying our own domestic developments from possible inimical foreign achievements." A 27 October memorandum for the Director of Central Intelligence repeats the request, floating "test vehicles in various stages of development."
So in October the Air Force was asking the CIA whether the objects were ours, and in November AMC told Cabell the available information said they were not. Both are in the same folder.
There is also a request, signed by Colonel W. R. Clingerman as acting chief of the Intelligence Department, for a Rand study. The attached requirements say the command has considered that some objects "may have been experimental spaceships," and add: "if such craft actually have been sighted, it is believed more likely that they represent the effort of a foreign nation, rather than a product from beyond the Earth."
The airline thread is where the checklists come in. A 9 September 1948 request asks that JANAP 146 be amended "so as to include commercial domestic airlines within its provisions." An AMC indorsement dated 26 October 1948 asks for help getting airlines to use an "Essential Elements of Information" check list alongside JANAP 146. The check list itself does not appear in the extracted text. Only the covering letter does.
One small item is filed with everything else. A letter dated 14 September 1948 from Mrs. Ruth Shook in Georgia asks the War Department what "the people in North Georgia have been seeing," things "some what like a giant cigar" with "a motor that sounds like a motorcycle." Then: "If they are American military machines I do not need to know about them."
Study 203
McCoy's November letter says a summary report was "nearly complete." The archive's next document on the subject is Air Intelligence Division Study No. 203, "Analysis of Flying Object Incidents in the U.S.," in two versions. DOW-UAP-D093 is dated 10 December 1948. DOW-UAP-D094 is catalogued as 28 April 1949 and described by AARO as a later revision, though its extracted text still carries the date 10 December 1948.
Study 203 counts "approximately 210 incidents." It lists "two reasonable possibilities," domestic devices or foreign ones, and says a foreign source would most logically be Soviet. It names the German Horten 229 as particularly resembling some descriptions, and notes that "as early as 1924 Tscheranowsky developed a 'Parabola' aircraft." Same word as the April inclosure list, now attached to a Soviet designer. The files do not connect the two, and I will not either.
The D094 version also has the scoreboard. AMC had "definitely established the identification of 18 of approximately 210," about nine percent. Three were hoaxes, two came from unreliable witnesses, and the other 13 turned out to be celestial bodies, balloons, or "airborne cosmic ray experimental equipment."
Its summary lands close to where AMC was in November: "it appears that some object has been seen; however, the identification of that object cannot be readily accomplished." Related disc reports across the release are collected on the disc and saucer sightings topic page.
Tallying across the files: 100 incidents in April, about 180 in November, about 210 in Study 203, with 18 of those explained. The explanations did not keep pace with the count. The blimp schedules, at least, got checked.