DOW-UAP-D097: The First Project Sign Progress Report - The First Hundred Sightings, 1948

Source file: DOW-UAP-D097_Project-Sign-Progress-Report_1948.pdf Originating agency: Headquarters, Air Materiel Command, U.S. Air Force, Wright-Patterson Air Force Base, Dayton, Ohio Document type: Initial progress report, with incident tabulation, photographs, photographic analysis, and an aviation-press enclosure Date: April 23, 1948 (enclosures dated February 19 to March 19, 1948) Classification: CONFIDENTIAL (declassified; release authority NND 927545) Page count: 45 (all read) VIRIN: 260710-D-D0360-1082 PURSUE Release: 4

Summary

This is the first official report of Project Sign, the U.S. Air Force's first program for investigating unidentified flying objects. The letter, sent on April 23, 1948 from Headquarters, Air Materiel Command at Wright-Patterson Air Force Base to the Chief of Staff of the Air Force in Washington (attention: Director of Intelligence), is signed by Colonel H. M. McCoy, the command's Chief of Intelligence, for the Commanding General. It opens with the words that define its status: "This is an initial report on unidentified flying objects," pursuant to the Headquarters USAF letter of December 30, 1947 signed by General L. C. Craigie under the subject "Flying Discs."

The core of the document is Inclosure 1: a detailed tabulation of the first one hundred incidents collected through February 1, 1948, recording date, hour, location, number of objects, observer's occupation, maneuvers, weather, color, shape, size, sound, exhaust trail, heading, altitude, and speed for each incident. Entries include the July 1947 series of sightings at Muroc Air Field, California; a June 24, 1947 observation over Mount Rainier whose particulars match Kenneth Arnold's famous report; and the series of observations at Godman Field, Kentucky on January 7, 1948 — the day pilot Thomas Mantell crashed while pursuing an unidentified object (observer names do not appear in the tabulation).

The report also includes two photographs from Incident No. 40 (Phoenix, Arizona, July 7, 1947) and a laboratory analysis dated February 19, 1948 which concluded that "the image is of true photographic nature" and estimated the object's diagonal at 44 to 55 feet. Alongside these, the command attached a photograph of the German "Horten Parabola" glider and a three-part article series from the British periodical The Aeroplane, "The Biology of the Flying Saucer," on the history of low aspect ratio aircraft. The command's bottom line: scientist Irving Langmuir remained skeptical, but the headquarters believed an aircraft could be built that would duplicate many of the characteristics of the reported "flying discs."

Research Article

From Craigie's Directive to the First Report: How Project Sign Began

The opening letter reconstructs the founding chain of the first official investigation program. On December 30, 1947, at the height of the public reverberations of the summer 1947 sighting wave, General L. C. Craigie, the Air Force's Director of Research and Development, signed a directive under the subject "Flying Discs" tasking Air Materiel Command with investigating the phenomenon. In its wake, McCoy reports, "Project HT-304 was activated on 26 January 1948 and Technical Instruction 2185, dated 11 February 1948, was published." The document notes that the project files consolidate reports received directly by Headquarters, AMC with those forwarded by the Director of Intelligence, USAF, and that quarterly reports would be submitted beginning July 1, 1948.

A small, telling detail: the command secured the schedules of lighted night-flying advertising blimps and cross-checked them against the reports to determine whether they might account for some incidents. Even at this early stage, the document projects the working posture of a systematic investigative body — filtering out mundane explanations before confronting the harder questions.

One Hundred Incidents in a Single Table: Anatomy of the 1947 Wave

Inclosure 1, the heart of the document, spreads the first hundred incidents (with sub-lettered entries, more than 110 rows in practice) across 28 pages, and from it come the statistics McCoy summarizes in the letter: the object was described as oval, disc, or saucer-shaped 31 times; associated sound was reported only 11 times; exhaust trails were reported 23 times; and 77 of the incidents involved a single object (21 incidents of 2 to 5 objects, 8 of 5 to 10, and 9 of more than ten). Reported sizes, in the document's words, "varied from that of a 25-cent piece to 250 feet in diameter, and from the size of a pursuit plane to the bulk of six B-29 airplanes." Speeds range "from very slow or hovering to supersonic," and a summary diagram of reported flight directions shows a dominance of northwest (63 objects) and north (38).

The tabulation also reveals the range of witnesses: Air Force officers from lieutenant to colonel, a United Airlines captain, Portland police patrolmen (some of them former pilots), an astronomer, a judge, the Lieutenant Governor of Idaho, a Coast Guardsman, engineers, and even "Hungarian peasants" from an incident in Budapest. The geography extends beyond the United States: Toronto and Newfoundland in Canada, Germany, Hungary, the North Sea off the Dutch coast, a ship at sea near Australia, and two incidents in Finland from January 1948. Most incidents cluster in the summer 1947 wave, but the records run into January 1948, and one incident (No. 31) dates back to mid-December 1946.

Two notes appended to the tabulation attest to early quality control: Incident No. 18 from Toronto was declared fraudulent ("both the photograph and story were a hoax, perpetrated for publicity and money"), and the reporter of Incident No. 84 was judged "an excitable person" with "an exaggerated imagination." The willingness to disqualify reports, alongside meticulous documentation of the rest, is what gives the tabulation its evidentiary weight.

Foundational Sightings Within the Table: Mount Rainier, Muroc, and Godman Field

Three clusters of entries in the tabulation record the foundational incidents of the early UFO era. Incident No. 17, from June 24, 1947 at 1500 hours over Mount Rainier, Washington, describes a private pilot who observed from the air nine "mirror bright" objects, "approximately circular, no tail," with a diameter "equal to distance between outboard engines of DC 4," in straight horizontal flight from north to south at 9,500 feet, in weather "clear as crystal." The particulars match, point for point, the report of Kenneth Arnold — the sighting that coined the term "flying saucers" — though his name appears nowhere in the document.

Incidents 1 through 4 record the observations at Muroc Air Field, California (later Edwards Air Force Base) on July 7 and 8, 1947: Air Force officers and sergeants watched silvery disc-like objects, one of which, per the entry, "descended from an intermediate altitude in an oscillating fashion almost to the ground, then started climbing again to a very high altitude and moved off slowly in the distance." Incident No. 4 describes an object with a "distinct oval outline," 50 feet across, with two projections on its upper surface.

The most dramatic cluster is the 33 series (33 through 33g): eight entries from January 7, 1948 at Godman Field, Kentucky and its vicinity. The witnesses include officers at the base, a colonel of the Kentucky State Police, and an Air Force captain identified in the table as a flight leader. The descriptions: a metallic or white object, "round tending to be conical," "1/4 size full moon," stationary at extremely high altitude at 210 degrees from Godman Field; entry 33f records 15,000 feet and 500 mph, and entry 33g, from Madisonville, describes a cone 100 feet high and 43 feet across. This was the day Captain Thomas Mantell, a National Guard pilot who took off to intercept the object seen over Godman Field, lost consciousness at high altitude and crashed. The document neither names him nor mentions the crash, but this series of entries is the official statistical record of that day, made just three months after the event.

Incident 40 and the Photo Analysis: "True Photographic Nature"

Inclosures 2 through 4 are devoted to Incident No. 40: an amateur photographer (whose surname the document spells "Rhoades"; in the research literature he is known as William A. Rhodes) photographed a gray elliptical object 20 to 30 feet across in Phoenix, Arizona on July 7, 1947. Per the tabulation, it appeared from the northeast, spiraled downward from 5,000 to 2,000 feet, then climbed away at a 45-degree angle at an estimated 400 to 600 mph. The witness reported a "noise like jet aircraft prior to its appearance," but no sound was heard while the object was in view.

The analysis memorandum of February 19, 1948 (Inclosure 4) is one of the earliest official examinations of a UFO photograph: "It is concluded that the image is of true photographic nature, and is not due to imperfections in the emulsion, or lack of development." The analysts further found that the "tail" in the image conformed to the type of shutter, the speed of the object, and the fixed shutter speed. Working from a 620 camera and a reported distance of 2,000 feet, they computed two scenarios for the object's diagonal: approximately 44 feet (4-inch focal length) or approximately 55 feet (5-inch focal length), with measurement points marked on an enlargement labeled Exhibit "A." In the cover letter, McCoy invites attention to "the marked similarity" between the Phoenix photographs and the Horten Parabola photograph in Inclosure 5, as well as the configurations illustrated in Inclosure 6.

The Institutional Hypothesis: Low Aspect Ratio and "The Biology of the Flying Saucer"

The letter's final paragraph exposes the interpretive debate inside the establishment as early as spring 1948. Command representatives visited Dr. Irving Langmuir, Nobel laureate in chemistry, at the General Electric Research Laboratories in Schenectady, New York. Langmuir held that the available data were insufficient for positive identification, and was "reluctant to consider the so-called 'flying discs' as a reality." The headquarters, however, staked out a position of its own: "it is possible to construct a low aspect ratio aircraft that would duplicate many of the appearance and performance characteristics of reported 'flying discs'" — through "the intelligent application of boundary layer control."

That hypothesis explains the final two enclosures. Inclosure 5 is a photograph of the Horten Parabola, a tailless crescent-shaped German glider built by the Horten brothers. Inclosure 6 is a three-part series from the British periodical The Aeroplane (February 13, March 5, and March 19, 1948) by aeronautical engineer A. R. Weyl: "The Biology of the Flying Saucer." The series surveys fifty years of experimentation with low aspect ratio, circular, and annular wings — from Gustave Koch's "turbine flying machine" (1893), through "Kitchen's doughnut" (1911) and Huth's annular biplanes, to Charles Zimmerman's NACA wind-tunnel work, the American Chance Vought V-173 and XF5U-1 experimental aircraft, German wartime delta developments, and ram-jet propulsion (the "Athodyd"). Weyl himself remained sober about identifying the saucers with secret aircraft: "it is inconceivable that whole squadrons of such unconventional aircraft could already be observed at air exercises." Attaching a trade-press article to an official intelligence report shows how strongly the "secret aircraft" hypothesis shaped the command's thinking — a line of analysis that would culminate in the "Analysis of Flying Object Incidents" studies of late 1948 and 1949 (see DOW-UAP-D093 and D094 in this collection).

Significance

This is the founding document of the official investigation: the first report produced by a dedicated government UFO program, just three months after its establishment. It fixes the earliest institutional statistics of the phenomenon (77 single-object sightings, 31 disc descriptions, speeds up to supersonic), records in real time the incidents that shaped the public conversation — from Mount Rainier to Godman Field — and contains the first official authentication of a UFO photograph, whose finding of "true photographic nature" stands unrebutted within the document.

No less important, the document captures the moment the institutional working hypothesis crystallized: not blanket denial, but an attempt to harness the aeronautical knowledge of the era (circular wings, low aspect ratio, boundary layer control) to explain the phenomenon. The tension between Langmuir's skepticism, the command's confidence in engineering feasibility, and data inconsistent with any known aircraft would accompany Project Sign until its closure in 1949, and its successors Grudge and Blue Book after it.

Key People

Locations

Incidents

Notable Quotes

"This is an initial report on unidentified flying objects as directed by Hq, USAF letter dated 30 December 1947, signed by General L. C. Craigie, subject: 'Flying Discs'." -- page 1

"High rate of climb, as well as the apparent ability to remain motionless or hover for a considerable length of time." -- page 1

"Reported sizes have varied from that of a 25-cent piece to 250 feet in diameter, and from the size of a pursuit plane to the bulk of six B-29 airplanes." -- page 1

"Dr. Langmuir was reluctant to consider the so-called 'flying discs' as a reality. However, it is believed at this Headquarters that it is possible to construct a low aspect ratio aircraft that would duplicate many of the appearance and performance characteristics of reported 'flying discs'." -- page 2

"It is concluded that the image is of true photographic nature, and is not due to imperfections in the emulsion, or lack of development in the section in question." -- page 33

"It has now been definitely determined that both the photograph and story were a hoax, perpetrated for publicity and money." -- page 29