The Kenneth Arnold Sighting

What the file holds

Project Blue Book’s papers on the case are one unit in the National Archives catalogue, “Mt. Rainer, Washington, June 1947” (NAID 28929152, 61 images). Among them:

• the record card (image 1), an undated summary in two typings (images 13, and 9 and 3) and the check-list for incident 17 with its narrative (images 18–19);
• the Air Materiel Command’s teletype of 10 July 1947 and Arnold’s telegram of 12 July 1947 (images 16–17);
• the memorandum of the CIC agent who interviewed Arnold on 12 July 1947 (image 31), and Arnold’s own written account with his drawing (images 35–41);
• J. Allen Hynek’s analysis and a note signed by him (images 5, 6, 2 and 10), and pages of the Project Grudge report (images 4, 7–8 and 12);
• press clippings, most of them of June and July 1947 (images 53–61), and galley proofs headed “THE WORLD OF FLYING SAUCERS” with two related pages (images 44 and 47–50).

Blue Book’s index lists the case on image 12 of NAID 28921348. The FBI’s file 62-HQ-83894 holds the Fourth Air Force report of 18 July 1947 with an unredacted copy of the CIC memorandum and of Arnold’s account (Section 2, pp. 159–167).

The sighting, in Arnold’s account

Arnold wrote his account at Wright Field’s request. On 10 July 1947 the Air Materiel Command thanked him “FOR PHOTO, BIOGRAPHICAL MATERIAL, AND FULL ACCOUNT OF UNIDENTIFIED AIRCRAFT INCIDENT” (image 16), and on 12 July he wired: “THIS REPORT WAS SENT TO YOU AT REQUEST SOME DAYS AGO.” (image 17) On 12 July he gave the CIC agent “a written report of exactly what he had seen”, attached to the agent’s memorandum as Exhibit A (image 31). The copy in the Blue Book file (images 35–41) carries no date; the FBI’s copy is headed “BY KENNETH ARNOLD” (Section 2, pp. 164–167).

It begins: “The following story of what I observed over the Cascade mountains, as impossible as it may seem, is positively true.” (image 35) After a flash on his plane, “I looked to the left and the north of Mt. Rainier where I observed a chain of nine peculiar looking aircraft flying from north to south at approximately 9,500 foot elevation” (image 36). He judged them to be between “twenty to twenty-five miles” away (image 37), measured the ridge between Mount Rainier and Mount Adams that the chain passed, “approximately five miles” long, and clocked the flight between the two mountains at “one minute and forty-two seconds” (image 38). His whole observation lasted “around two and one-half or three minutes” (images 38–39). Of what he saw he wrote: “it is just as much a mystery to me as it is to the rest of the world.” (image 41)

Shape and motion, in his words

• Shape. He calls them “saucer like objects” (image 38), and: “when the sun reflected from one or two or three of these units, they appeared to be completely round” (image 39). In level flight “they were just a black thin line” (FBI file, Section 2, p. 166). His drawing shows another outline: “They seemed longer than wide, their thickness was about 1/20th of their width”, with the notes “Mirror Bright” and “They did not appear to me to whirl or spin but seemed in fixed position, traveling as I have made drawing.” (image 41)
• Motion. “They flew like many times I have observed geese to fly in a rather diagonal chain-like line as if they were linked together.” They held a direction “but rather swerved in and out of the high mountain peaks”, and he watched them “flip and flash in the sun” (image 37). “I thought it was very peculiar that I couldn’t find their tails” (image 36).
• What he took them for. “I am convinced in my own mind that they were some type of airplane, even though they didn’t conform with the many aspects of the conventional type of planes that I know.” (image 39)

The check-list and the speed

The check-list for incident 17 records “Time in sight 2-1/2 to 3 minutes”, “Size Approximately that of DC-4 - 45 to 50 ft” and “Shape Approximately circular” (image 18). Its narrative says: “Clocked speed and found it to be approximately 150 MPH.” (image 19) That does not agree with the account, which has the objects cross from Mount Rainier to Mount Adams in one minute and forty-two seconds; Hynek’s analysis gives that speed as “approximately 1700 MPH” (image 2). The files do not explain the difference. The record card has the objects “heading west” (image 1); the account and the check-list have them flying from north to south (images 18, 36).

Where “saucer” comes from in the files

The words about a saucer skipping on water are not in Arnold’s account. They appear in two places:

• The undated Blue Book summary, which cites an interview the file does not hold: “In a subsequent interview Mr. [blacked out] described the objects as appearing like saucers skipping on water. This description was shortened to ‘Flying Saucers’ by newspaper men and resulted in the popular use of this term.” (image 13)
• The proofs of a book, which give no source: “Talking with a reporter that evening, Arnold said that the objects ‘flew like a saucer would if you skipped it across the water.’” (image 47)

The earliest press in the file attributes a shape to him. The Associated Press, in the Dayton Daily News of 26 June 1947: “Arnold described the objects as ‘flat like a pie pan,’ and so shiny that they reflected the sun like a mirror.”, with a motion “like the tail of a kite” (image 57). A clipping dated by hand June 27, 1947: “nine saucer-shaped, shiny objects dipping and skimming through the sky between Mt. Rainier and Mt. Adams” (image 61).

The Air Materiel Command wrote of the case’s influence: “There are strong indications that this report and its attendant publicity is largely responsible for subsequent reports.” (image 4) Project Grudge adds that two of its remaining unexplained reports “would not have been made had the witnesses not read of the Mt. Ranier incident (Incident No. 17)” (image 12).

What the file says about its label

The record card concludes “Other (MIRAGE)”, and Blue Book’s index has “24 Mt Ranier, Washington ... Other (MIRAGE)” (NAID 28921348, image 12). The undated summary: “It is the Air Force conclusion that the objects of this sighting were due to a mirage.” (image 13) It draws this from Arnold’s words about the air: his statement “concerning how smooth and crystal clear the air was is an indication of very stable conditions”, and such conditions “are associated with inversions which increase the refraction index of the atmosphere” (image 3). The file holds no weather data for the day.

What the other papers in the file say:

• The CIC agent, 16 July 1947. “It is the personal opinion of the interviewer that Mr. [blacked out] actually saw what he stated that he saw.” Having checked an aeronautical map, he found that the statements on “distances involved, speed of the objects, course of the objects and size of the objects, could very possibly be facts.” (image 31)
• Hynek, undated. “There appears to be no astronomical explanation for this classic incident” (image 5). He finds the reported distance and size “mutually contradictory” and concludes: “In all probability, therefore, objects were much closer than thought, and moving at definitely ‘sub-sonic’ speeds.” (image 10) His analysis ends: the objects “may, therefore have been some sort of known aircraft” (image 2).
• The Air Materiel Command, undated. “The entire report of this incident is replete with inconsistencies.” And: “The report cannot bear even superficial examination, therefore, must be disregarded.” (image 4)
• Project Grudge, undated. Hynek’s index puts incident 17 under “Evidence offered suggests no explanation” (image 8), and the report lists it among the remaining unexplained incidents (image 12).

Arnold himself rejected a mirage: “A number of news men and experts suggested that I might have been seeing reflections or even a mirage. This I know to be absolutely false” (image 38). No document in the file proposes birds.

The papers disagree about the case, so its status is disputed. They hold no instrument record of the objects: the distance, the size and the timing are Arnold’s own estimates, and Hynek showed that they contradict one another. The mark ◆ does not apply.

Evidential value

One observer, no photograph and no radar. There is a record all the same: Arnold’s written account with his drawing, made within a few weeks, and the check-list made from it. And the geometry has been worked out twice: the CIC agent checked Arnold’s distances against an aeronautical map and found that they “could very possibly be facts” (image 31), while Hynek recomputed size and speed from Arnold’s figures (image 6) and called them “mutually contradictory” (image 10).

Tacoma, July 1947

Arnold also appears in the FBI’s file on the Maury Island fragments: on 22 July 1947 Raymond A. Palmer of the Venture Press offered by letter to pay his expenses for a trip to Tacoma, where Harold A. Dahl and two other seamen were said to have seen six discs near “Murry Island” [sic], because he wanted someone “to find out if these boys are on the up and up”. Arnold went, and on 19 August 1947 he told the FBI in Boise what he had heard there.

Where it was

The check-list gives the place of observation as “Near Mineral, Washington” (image 18). Arnold was over the Cascade Range; the objects, first seen to the north of Mount Rainier, passed its southern edge and then a ridge between Mount Rainier and Mount Adams (images 36–38). No document gives coordinates. The pin is OpenStreetMap’s point for Mineral (node 150959545, 46.7171° N, 122.1809° W), rounded to 46.72° N, 122.18° W. It marks the place named on the check-list, not the position of the aircraft or of the objects.

Why this scores where it does

Witnesses: 2. One witness, an experienced private pilot, who wrote his account within weeks and was interviewed by a CIC agent. Not higher: no second witness is in the file, and the Air Force’s analysts found the account “replete with inconsistencies” (image 4) and its figures “mutually contradictory” (image 10).

Radar: 0. None.

Optics: 0. No photograph of the objects; the drawing is not an imaging record.

Physical trace: 0. None.

Multi-channel: 1. One observer; the press repeats him.

Documentation: 4. The account, the check-list, the CIC memorandum, the teletype and the telegram, Hynek’s analysis, the Grudge pages, the summary and the index can all be opened, and the FBI holds an unredacted copy. Not 5: the evaluations contradict one another, the card gives the wrong direction, and the interview the summary cites is not in the file.

Anomaly: 2. Hynek’s calculation undoes the speed of about 1,700 miles an hour; what remains are tailless objects that flipped and flashed, by one witness.

Data today: 2. Arnold’s figures can be recomputed, as Hynek did, and checked against a map, as the CIC agent did; there is no instrument record.

The overall is 1.3: class D, testimony only.

What would settle it

• The “subsequent interview” that the Blue Book summary cites for the saucers skipping on water (image 13).
• The agency dispatches of 25–26 June 1947, beyond the two clippings in the file.
• The date of Arnold’s written account.
• The photograph for which the Air Materiel Command thanked him on 10 July 1947 (image 16), which the file does not identify.