The Complete Sighting Report of Kenneth Arnold with Comments and Analysis

Maccabee, B. S.: Publication #246, 24 juin 2001

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The sources of information

Summaries of Arnold's sighting report have been published in a number of books (1,2,3,4,5,6,7,8,9) including his own (10). Unfortunately these books leave out some of the details that must be known in order to properly evaluate (and reject!) the explanations which have been proposed. I, too, do not have space to reproduce his sighting report (11) verbatim. However, I will present most of the information so that the reader will have a good understanding of what happened.

What was he doing before the sighting ?

According to Mr. Arnold, at 2:00 PM, June 24, 1947 he took off from Chehalis, in the state of Washington, in his small plane after completing a business trip (he sold and installed fire fighting equipment). He planned to spend about an hour searching for a lost C-46 Marine transport plane that had crashed in the mountains west-southwest of Mt. Rainier. (There was a $5,000 reward for finding the plane.) After searching for about an hour and not finding anything he turned east toward his next destination, Yakima, Washington. He was near Mineral, Washington, about 22 miles west-southwest of Mt. Rainier and Yakima was about 80 miles ahead of him along a flight path that would take him just about 12 miles south of peak of Mt. Rainier. He levelled out onto his new flight path he was at approximately a 9,200 ft altitude. His sighting began within a minute or two of the turn. Sentences and paragraphs taken from his Air Force letter (11) are preceded by (L) and statements from his book (10) are preceded by (B). As you read the following story please keep in mind that this is history. It actually happened!

****** (L) "The air was so smooth that day that it was a real pleasure flying and, as most pilots do, when the air is smooth and they are flying at a higher altitude, I trimmed out my airplane in the direction of Yakima, which was almost directly east of my position and simply sat in my plane observing the sky and terrain. There was a DC-4 to the left and to the rear of me approximately fifteen miles distance, and I should judge, at 14,000 ft. elevation. ******

COMMENT: The time was about 3:00 PM and the sun was just slightly to the southwest of being directly overhead (this was only two days after the summer solstice). It is important to notice how Arnold's attention was first drawn to the presence of strange flying objects because his initial observation rules out any explanation that is based on things in the sky which are not shiny (reflective, like a mirror) such as, for example, birds. It also rules out atmospheric effects.

******* (L) "The sky and air was as clear as crystal. I hadn't flown more than two or three minutes on my course when a bright flash of light reflected on my airplane. It startled me as I thought I was too close to some other aircraft. (B) I spent the next twenty to thirty seconds urgently searching the sky all around - to the sides and above and below me - in an attempt to determine where the flash of light had come from. The only actual plane I saw was a DC-4 far to my left and rear, apparently on its San Francisco to Seattle run. My momentary explanation to myself was that some lieutenant in a P- 51 had given me a buzz job across my nose and that it was sun reflecting off his wings as he passed that had caused the flash. Before I had time to collect my thoughts or to find a close aircraft, the flash happened again. This time I caught the direction from which it had come. I observed, far to my left and to the north, a formation of very bright objects coming from the vinicity of Mt. Baker, flying very close to the mountain tops and traveling at tremendous speed. (L) I observed a chain of nine peculiar looking aircraft flying from north to south at approximately 9,500 ft elevation and going, seemingly, in a definite direction of about 170 degrees. *******

COMMENT: Mt. Baker (altitude, 10,000 ft) is about 130 miles north of Mt. Rainier. Even if the objects were not as far away as Mt. Baker the flashes must have been very bright to be visible over a great distance. This suggests that the flashes were reflections of sunlight from mirror-like (specular) surfaces, i.e., a polished metal surfaces. Anything less would be invisible over such a distance in the bright sky. Since the sun was nearly overhead, some portion of the object's surface must have been momentarily at an angle of nearly 450 to the vertical (or horizontal) in order to cause a reflected sun ray to travel nearly horizontally in the atmosphere from the object to Arnold's plane.

******* (B) "At first I couldn't make out their shapes as they were still at a distance of over a hundred miles. I could see that the formation was going to fly in front of me. I watched as these objects approached the snow border of Mt. Rainier, thinking all the time that I was observing a whole formation of jets. In group count that I have used in counting cattle and game from the air, they numbered nine. They were flying diagonally in echelon formation with a larger gap in their echelon between the first four and last five. What startled me the most was the fact that I could not find any tails on them. I felt sure that, being jets, they had tails, but figured they must be camouflaged in some way so that my eyesight could not perceive them. I knew that the Air Force was very artful in the knowledge and use of camouflage. I observed the objects' outlines plainly as they flipped and flashed against the snow and also against the sky.

(L) Anyhow, I discovered that this was where the reflection had come from, as two or three of them every few seconds would dip or change course slightly, just enough for the sun to strike them at an angle that reflected brightly on my plane.

(B) As they were traveling perpendicular to my path I was in an excellent position to clock their speed and I determined to make an attempt to do so.

(L) I had two definite points I could clock them by. (Note: by this he means Mt. Rainier and Mt. Adams, about 47 miles to the south). The air was so clear that it was very easy to see the objects and determine their approximate shape and size at almost fifty miles that day. I remember distinctly that my sweep second hand on my eight day clock, which is located on the instrument panel, read one minute to 3 PM as the first object of this formation passed the southern edge of Mt. Rainier.

(L) I watched these objects with great interest as I had never before observed airplanes flying so close to the mountain tops, flying directly south to southeast down the hog's back of a mountain range. I would estimate their elevation could have varied a thousand feet one way or the other up or down, but they were pretty much on the horizon to me which would indicate that they were near the same elevation as me. 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 seemed to hold a definite direction but rather swerved in and out of the high mountain peaks. I could quite accurately determine their pathway due to the fact that there were several high peaks a little this side of them as well as higher peaks on the other side of their pathway. *******

COMMENT: These statements about how they flew with respect to the mountain peaks are very important because they provide information on the distance from Mr. Arnold. These mountain peaks lie along a wide north-south line extending southward from Mt. Rainier to Mt. Adams. These peaks were about 20 miles east of Arnold at the time. These statements also provide the altitude of the objects. To Arnold they appeared to be approximately at his altitude because they seemed to be "pretty much on the horizon to me." Since he was flying at 9,200 ft, this implies that they were close to that altitude. (Arnold actually stated his letter that they were at 9,500 ft.) However, the mountain peaks south of Rainier generally are 5,000 to 7,000 ft high, with the higher ones being farther away (more to the east) from Arnold. Hence his statement that there were higher peaks on the far side of the pathway indicates that the objects were definitely lower than about 7,000 ft. Furthermore, he stated that they went behind some (or at least one) of the lower, closer peaks. Geological survey maps show that mountain peaks which the objects could have disappeared behind have altitudes of 5,000 to 6,000 ft. Hence it appears that they were lower than 6,000 ft and that Arnold overestimated their altitude.

Is it reasonable to assume that he could have made an error of several thousand feet in estimating their altitude? The answer to this question lies in the fact that Arnold inferred the altitude by observing that the objects appeared to be almost exactly on his horizon (i.e., level with his altitude). But it is very difficult to determine the exact horizon from an airplane. In this case, the angle (the "depression angle") between exact horizontal and his downward sighting line to the mountain peaks south of Mt. Rainier was very small. The depression angle from Arnold's plane at 9,200 ft altitude to the top of a 5,500 ft high mountain at a distance of 20 miles (105,600 ft) was about 20. Such a small angle would be difficult to detect from an airplane. So the answer is yes, he could easily have made an error of 4,000 ft in estimating the altitude of the objects. Perhaps if he had looked up the actual altitudes of the mountain peaks south of Mt Rainier he would have revised his statement.

While Arnold was timing the flight he observed the objects carefully. According to his letter, " I observed these objects not only through the glass of my airplane but turned my airplane sideways where I could open my window and observe them with a completely unobstructed view. (Without sun glasses.)"

******* (B) "They didn't fly like any aircraft I had ever seen before. In the first place their echelon formation was backward from that practiced by our Air Force. The elevation of the first craft was greater than that of the last. They flew in a definite formation but erratically. As I described them at the time their flight was like speed boats on rough water or similar to the tail of a Chinese kite that I once saw blowing in the wind. Or maybe it would be best to describe their flight characteristics as very similar to a formation of geese, in a rather diagonal chain-like line, as if they were linked together. As I put it to newsmen in Pendleton, Oregon, they flew like a saucer would if you skipped it across the water. They fluttered and sailed, tipping their wings alternately and emitting those very bright blue-white flashes from their surfaces. At the time I did not get the impression that the flashes were emitted by them, but rather that it was the sun's reflection from the extremely highly polished surface of their wings.

(L) What kept bothering me as I watched them flip and flash in the sun right along their path was the fact that I couldn't make out any tail on them, and I am sure that any pilot would justify more than a second look at such a plane. The more I observed these objects the more upset I became, as I am accustomed and familiar with most all objects flying whether I am close to the ground or at higher altitude. Even though two minutes seems like a very short time to one on the ground, in the air in two minutes time a pilot can observe a great many things and anything within his sight of vision probably as many as fifty or sixty times. Of course, when the sun reflected from one or two or three of these units, they appeared to be completely round; but, I am making a drawing to the best of my ability, which I am including, as to the shape I observed these objects to be as they passed the snow covered ridges as well as Mt. Rainier. When the objects were flying approximately straight and level, they were just a black thin line and when they flipped was the only time I could get a judgement as to their size. These objects were holding an almost constant elevation; they did not seem to be going up or coming down, such as would be the case of artillery shells. 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 types of planes I know. *******

COMMENT: In his letter Arnold included a sketch which shows the leading edge being nearly a semicircle, with short parallel sides and with the rear being a wide angle convex (protruding) V shape that comes to a rounded point at the trailing edge. His drawing suggests that the objects were nearly circular overall. He wrote on the sketch that "they seemed longer than wide, their thickness was about 1/20th of their width." His suggestion that their width (or length) was about twenty times greater than their thickness may be an exaggeration. The sketch he drew of how they appeared"on edge" has the dimensions 4 mm wide by 45 mm long (approx.) which suggests a ratio closer to 1/11. (It is typical for people to overestimate length to width ratios.) Although he did not mention it in his letter, he later stated (e.g., in his book) that one of the objects had a somewhat different shape. His book shows an illustration in which the object has a semi-circular front edge and a read edge that consists of two concave edges that join at a rearward pointing cusp at the center of the rear edge.

****** (L) I knew they must be very large to observe their shape at that distance, even on as clear a day as it was that Tuesday. In fact I compared a zeus fastener or cowling tool I had in my pocket - holding it up on them and holding it up on the DC-4 - that I could observe at quite a distance to my left, and they seemed smaller than the DC-4; but I should judge their span would have been as wide as the furtherest engines on each side of the DC-4.

(L) I observed the chain of these objects passing another snow-covered ridge in between Mt. Rainier and Mt. Adams, and as the first one was passing the south crest of this ridge the last object was entering the northern crest of the ridge. As I was flying in the direction of this particular ridge, I measured it and found it to be approximately five miles so I could safely assume that the chain of these saucer like objects were at least five miles long.

(L) As the last unit of this formation passed the southern most high snow covered crest of Mt. Adams, I looked at my sweep second hand and it showed that they traveled the distance in one minute and forty-two seconds. Even at the time this timing did not upset me as I felt confident after I would land there would be some explanation of what I saw. I might add that my complete observation of these objects, which I could even follow by their flashes as they passed Mt. Adams, was around two and one-half or three minutes--although, by the time they reached Mt. Adams they were out of my range of vision as far as determining shape or form. *******

COMMENT: Arnold provided an estimate of size in an indirect way: he stated that they appeared to be comparable to the spacing of the engines on a DC-4 (4 engine propellor driven, 117 ft wingspan, 94 ft length, 27 ft height) which he had seen at a distance which he estimated as 15 miles. He estimated the engine spacing to be 45 - 50 ft, although 60 ft would have been a better estimate. By this means he was essentially providing an angular size for the objects: the equivalent of about 60 ft at 15 miles. He reported the size of the objects as 45 - 50 ft by comparison with the airplane as if the plane had been at the same distance as the objects. However, the plane was not at the same distance, so a correction for the distance difference is necessary.

It is possible to make an estimate of the size of the objects assuming his estimate of the distance to the DC-4, 15 miles, was (approximately) correct. (Here comes some math and geometry, so if you are squeemish about such subjects, skip over the next four sentences.) Using the outer engine spacing as 60 ft, the angular size at his estimated distance is 60/(15 x 5280) = 0.00076 radians or about 2.6 minutes of arc (1 degree = 60 minutes = 0.0174 radians). Projecting this angle to 20 miles, the rough distance of the objects, would yield a size of about (20 x 5280 x 0.00075 = ) 80 ft. Had he overestimated the distance to the DC- 4 (if it had been less than 15 miles away) the calculated angular size, and hence the calculated object size would increase. If he underestimated the distance to the DC-4, then the calculated size would decrease. My own suspicion is that he overestimated the distance and that therefore the objects were larger than 80 ft in length. Unfortunately no investigator pursued this size estimate at the time and with Arnold's death many years ago it is no longer possible to improve the size estimate.

Using the dashboard clock in his airplane Arnold measured the time from when the first object passed the flank of Mt. Rainier until the last object passed Mt. Adams. The distance from the flank of Mt. Rainier to the peak of Mt. Adams is about 45 miles (depending upon where on the flank one picks as the starting point). Since the length of the "chain" of objects was about 5 miles (paragraph H above), the leading object was about 5 miles south of Mt. Adams when the last object passed Mt. Adams. Hence the total distance it (and the others) traveled was about 50 miles in 102 seconds. This corresponds to a speed of about 1,760 mph. (Arnold intentionally underestimated this speed, saying that it was 1,200 mph or more, which was still faster than any aircraft of the day. Chuck Yaeger was the first person to "break" the "sound barrier" at about 700 mph several months after Arnold's sighting.)

Arnold estimated that he had the objects in view for a total of about 2.5 to 3 minutes, during which time they may have traveled 80 to 90 miles, from a location about 30 or 40 miles north of Mt. Rainier where Arnold first saw them (not from the 100 miles distance of Mt. Baker, as Arnold had thought) to some distance south of Mt. Adams, where they disappeared from view.

When Arnold landed at Yakima, Washington, he told some of the people at the airport about these amazing high speed aircraft.

******* (L) When I landed at Yakima, Washington airport I described what I had seen to my very good friend Al Baxter, who listened patiently and was very courteous but in a joking way didn't believe me. ******

COMMENT: Arnold then left the airport to fly to Pendleton, Oregon on a business trip. The discussion of his sighting presumably would have ended in Yakima if it hadn't been for the fact that someone at the airport contacted the press to report that some new, high speed aircraft had been sighted. When Arnold arrived at Pendelton he was surprised to find a number of reporters eager to learn about the new aircraft. Arnold told them about the sighting and his (under)estimated speed of 1,200 mph. He then described how they flew: they wobbled and flipped, like saucers skipping on the water. A reporter, hearing the description, coined a name for the new aircraft, a name which we have been stuck with ever since: FLYING SAUCERS.

******* (L) I did not accurately measure the distance between these two mountains (Note: Rainier and Adams) until I landed at Pendleton, Oregon, that same day where I told a number of pilot friends of mine what I had observed and they did not scoff or laugh but suggested they might be guided missiles or something new. In fact several former Army pilots informed me that they had been briefed before going into combat overseas that they might see objects of similar shape and design as I described and assured me that I wasn't dreaming or going crazy. .....A former Army Air Forces pilot ...(told me)..."What you observed, I am convinced, is some type of jet or rocket propelled ship that is in the process of being tested by our government or even it could possibly be by some foreign government."


The official Air Force explanation is that Arnold saw a mirage. Having read the previous material you may wonder how the Air Force could justified that explanation. The answer is not straightforward. Initially the Air Force intelligence officers who were collecting saucer reports treated the sightings, including Arnold's, seriously. This was, at least in part, a result of the fact that a number of Air Force pilots reported seeing flying saucers. Arnold's sighting was included as unexplained in the Top Secret intelligence memorandum (3). However, in the fall of 1948 General Hoyt Vandenburg rejected the conclusion expressed in the "Estimate of the Situation" that saucers were interplanetary vehicles. The only alternative, that the Russians had made immense improvements on German aircraft developed during WWII and were flying their new aircraft over the United States, was too much for the intelligence analysts to accept. Therefore they had no alternative but to explain each sighting in some conventional way. The "urge to explain" carried over into Projects Sign and Grudge.

Explanations for Arnold's sighting were proposed by two scientists with close connections to the Air Force project. Their explanations have had the most impact on the final Air Force evaluation of the sighting. These skeptical scientists were Dr. J. Allen Hynek and Dr. Donald Menzel. Dr. Hynek, a professor at Ohio State University and then at Northwestern University, was the astronomy consultant to the Air Force's UFO projects starting with Project Sign in 1948 and continuing through the end of Project Blue Book in 1969. Although his specialty was astronomy he was asked to suggest explanations for all types of sightings. Dr. Menzel was an astrophysicist and director of the Harvard Observatory during the same time period. Dr. Hynek, who died in 1986, reversed his skeptical stance toward UFO reports in the late 1960's and, in 1973, founded the Center for UFO Studies, headquartered in Chicago, Illinois. Dr. Menzel, who died in 1976, never retreated from his published opinion that all sightings by credible observers could be explained, many as meteorological phenomena.

In 1948 Dr. Hynek (who was not aware of the Top Secret Air Intelligence Report (3)) was hired to analyze sightings and to decide which ones could be catagorized as misidentified astronomical phenomena. As a "side benefit" to the Air Force he also gave his opinion on the other sightings, including Arnold's. (9)

Hynek began his analysis of the sighting by assuming that at least part of what Arnold said was true: that Arnold could see the overall shape of the objects, that he could see them edge-on, and that he thought their width was about twenty times greater than their thickness. Hynek decided to try to calculate their size based on the basic visual capabilities of the human eye. He pointed out that the angular resolution of the human eye is typically about 3 minutes of arc (1 minute of arc = 1/60 of a degree = 0.00029 radians; the angular size of the moon is about 1/2 degree or about 30 minutes of arc). He then argued that if the angular size, i.e., thickness, were substantially less than this then Arnold couldn't have seen them. Hence, Hynek concluded that the thickness must have been at least 3 minutes of arc which is about one tenth of the apparent size of the moon. Hynek calculated that this angular size corresponds to a thickness of about 100 feet at the greatest distance estimated by Arnold, 25 miles. Therefore, if Arnold's 20:1 ratio of length to thickness were correct, then the objects were about about 2,000 ft long, a size that seemed to Hynek to be just too ridiculously large.

But Arnold had estimated that the objects were the size of fighter aircraft with typical lengths of 40 to 50 ft. Aha, said Hynek...a contradiction! There is an error somewhere. Hynek calculated that, if, indeed, they had been this short then they would have been too small for Arnold to see any details. Furthermore, if the 20:1 ratio were correct, they would have been too thin to see edge-on if 25 miles away. Thus Hynek noted an inconsistency in Arnold's report: if the objects' size and distance were as estimated by Arnold he could not have seen any details of their shape because he could not have been seen them at all!

Hynek decided to resolve the inconsistency by ignoring both Arnold's distance and size estimates. Instead, Hynek argued that if the objects were a more reasonable size, say, the size of the largest known aircraft, roughly 400 ft long and 30 feet high, then they must have been much closer to Arnold in order for them to be seen "edge on." Hynek estimated their distance at 6 miles. At this distance the aircraft could appear (from the position of Arnold's plane) to travel past Mt. Rainier and then past Mt. Adams in 102 seconds if their speed were only about 400 mph. Hynek concluded as follows: "in view of the above (calculations) it appears probable" that Arnold saw "some sort of known aircraft."

If you reread the above analysis you will see that Hynek explained Arnold's sighting by assuming the objects were the size of ordinary large aircraft and then concluding that the objects probably were ordinary aircraft. Clever!

As a result of Hynek's discussion of the discrepancy between Arnold's estimates of the distance and size of the objects, the Air Force officers who wrote the final report of Project Grudge in the spring of 1949 decided that "the entire report of this incident is replete with inconsistencies" and cannot bear even superficial examination." (9)

So, what about Hynek's argument that the objects would have been too thin to be visible, based on his claim that the human eye can't see something smaller than 3 arc minutes in angular size? Does it make any sense at all? The answer to this question is no, and it comes in two parts. First, the fact is that many people can "see" objects smaller than 3 arc minutes in angular size, especially if they are larger than this in one dimension (e.g., like a long cylinder viewed from the side). The second part of the answer comes directly from Arnold's report to the Air Force. Although it would have been "nice" if Arnold could have taken an eye test to provide Hynek with actual visual acuity data, the fact is that some information in his report, information that Hynek ignored, provides us with a clue as to Arnold's visual acuity. He said he was able to see a DC-4 at 15 miles (estimated distance) and he compared the spacing of the engines on the plane with the apparent size of the saucers. With its visible height of about 23 ft, the vertical angular size of the DC-4 at that distance was about 0.00034 radians or about 1 arc minute. (Even if Arnold overestimated the distance and it was really 10 miles away then vertical angular size would still have been less then 2 arc minutes.) Hence, by Hynek's criterion, Arnold should not have been able to see the DC-4, and certainly he wouldn't have been able to see the engines and thereby to see the spacing of the engines. But Arnold said that he did see the airplane and its engines and Hynek did not dispute that statement. Therefore Hynek's objection...the "inconsistency"... must be rejected.

Had Dr. Hynek tested his hypothetical explanation - "known aircraft" - against the information in Arnold's report he might have rejected his own explanation. To test Hynek's explanation assume that the unknown objects were ordinary large aircraft six miles away and ask the following question: why wasn't Arnold able to identify them, to see their engines, tails, wings, etc., even though Arnold was able to identify another aircraft that was about 15 miles away? Evidently Hynek did not notice the inconsistency in his own analysis. Had Hynek done what skeptics usually fail to do, that is, to thoroughly test his suggested explanation against the data, he would have seen that his hypothetical solution failed.

It is amusing to imagine what would have happened if Hynek had accepted Arnold's distance estimate. Then he would have been forced to accept the high velocity (about 1,700 mph), in which case it is conceivable that the early history of the UFO subject would be different from what actually occurred. But instead, Hynek, for "good scientific reasons", I presume, chose to take the road more traveled reject important parts of Arnold's sighting...and that has made all the difference (with apologies to Robert Frost!). The handwriting was on the wall, but Hynek looked the other way.

Dr. Hynek's work was done secretly for the Air Force and his discussion of Arnold's sighting was not published, although his conclusion was mentioned in the "Project Saucer" report published by the Air Materiel Command at Wright Field (now Wright- Patterson Air Force Base) on April 27, 1949. Few civilian scientists had access to Air Force files and so there was no dispute of Hynek's analysis until Dr. Donald Menzel decided to write about Arnold's sighting in his first book on UFOs20, which was published in 1953. This was the first flying saucer book by a scientist and, because of his stature in the field of astrophysics, it was treated very seriously. It received favorable reviews, although there were some atmospheric scientists who questioned Menzel's use of weather phenomena to explain sightings. Libraries and scientific organizations throughout the United States and in other countries ordered the book and it became the main reference for scientists in the following years. In retrospect this is unfortunate since, as I will demonstrate, Menzel did not provide accurate descriptions of the sightings and he apparently slanted the data as necessary to make his explanations fit, beginning with Arnold's sighting.

Although he was an avowed skeptic, Menzel criticized the Air Force for accepting Hynek's explanation. He gave a brief description of Arnold's sighting and mentioned Arnold's estimate of distance and total sighting duration (3 minutes). Menzel wrote, "He clocked the speed at about 1,200 miles an hour, although this figure seems inconsistent with the length of time that he estimated them to be in view. From his previous statement they could scarcely have traveled more than 25 miles during the three minutes that he watched. This gives about 500 miles an hour, which is still a figure large enough to be startling.." Menzel did not tell the reader that Arnold had timed the flight of the objects between two points. Instead, Menzel substituted a travel distance which he got out of "thin air," 25 miles, and implied that this distance was covered in 3 minutes (180 seconds). Hence he was able to assign a much lower, although "startling," speed of 500 mph.

Menzel went on to "solve" the mystery of Arnold's sighting: "Although what Arnold saw has remained a mystery until this day, I simply cannot understand why the simplest and most obvious explanation of all has been overlooked.... the association of the saucers with the hogback (of the mountain range).... serves to fix their distance and approximate size and roughly confirms Arnold's estimate of the speed." (my emphasis; note that Menzel, unlike Hynek, accepted Arnold's distance estimate). Menzel then went on to suggest that Arnold saw "billowing blasts of snow, ballooning up from the tops of the ridges" caused by highly turbulent air along the mountain range. According to Menzel, "These rapidly shifting, tilting clouds of snow would reflect the sun like a mirror...and the rocking surfaces would make the chain sweep along something like a wave, with only a momentary reflection from crest to crest."

This first explanation by a scientist with the reputation of Dr. Menzel may seem slightly convincing, but only until one realizes that (a) the sighting occurred at 3:00 PM when the sun was high in the sky and somewhat west of Arnold, (b) snow cannot reflect light rays from the overhead sun into a horizontal direction "like a mirror" to create the very bright flashes that Arnold reported, (c) there are no 1,200 mph or even 500 mph winds on the surface of the earth to transport clouds of snow (fortunately!), (d) there are no winds that would carry clouds of snow all the way from Mt. Rainier to Mt. Adams (Arnold saw the objects pass Mt. Adams before they were lost to his view), (e) Arnold flew south of Mt. Rainier minutes later and surely his plane would have been strongly buffeted (and perhaps destroyed!) by such high winds, but he reported, instead, very calm conditions, (f) an atmospheric oscillation wave can't bend or reflect light over an angle of nearly 900, which would be necessary to make it appear as if the sun had been reflected by objects nearly at Arnold's altitude, and (g) an atmospheric oscillation wave with a "phase velocity" of 1,200 mph is unlikely, but in any case, when traveling southward its crests would be oriented east-west, so if it reflected any sunlight at all (highly unlikely), the reflection would be in the north-south direction and not westward toward Arnold's plane. Furthermore, even if such amazing atmospheric phenomena had occurred, it is difficult to imagine how Arnold could have failed to realize that he was just seeing snow blowing from the mountain tops, especially since he flew over the mountains about 12 miles south of Mt. Rainier on his way east just a few minutes after the sighting.

In case the first explanation wasn't sufficiently convincing, Menzel offered "another possibility:" he suggested that perhaps there was a thin layer of fog, haze or dust just above or just below Arnold's altitude which was caused to move violently by air circulation and which reflected the sunlight.20 Menzel claimed that such layers can "reflect the sun in almost mirror fashion." Menzel offered no substantiation for this claim. Perhaps he was thinking in terms of a "reflection" from an atmospheric layer when the sun is so low on the horizon that the light rays make a "grazing angle" with the layer. If so, then that explanation as applied to the Arnold sighting makes no sense since the sun was almost overhead (and slightly behind) Arnold. Furthermore, layers form under stable conditions and violent air circulation would tend to break them up so there would be no "reflections" of sunlight. Again, one wonders how Arnold could have failed to notice that he was just seeing the effects of a haze layer.

Ten years after his first book, Dr. Menzel offered his third, fourth and fifth explanations in his second book (written with Lyle Boyd): mountain top mirages, "orographic clouds" and "wave clouds in motion". To support the third explanation he presented a photograph of mountain top mirages taken by a photographer many years earlier, and proposed by the photographer, as the explanation for Arnold's sighting. The mirages appear as vague images above the tops of the mountains. (Actually the mirage is an inverted image of the top of the mountain.) These mirages can be seen under proper atmospheric conditions (requiring a stable atmosphere) when the line of sight from the observer to the mountain top is tilted by no more than one half of a degree above or below horizontal. Unintentionally (or intentionally?) Menzel failed to report in his book the following information in Arnold's report: as they traveled southward he saw them silhouetted against the side of Mt. Rainier which is 14,400 ft high, much higher than the altitude of the saucers. Since mountain top mirages occur above the mountain peaks these objects were far below any mirage of Mt. Rainier. Of course, mountain top mirages stay above the tops of the mountains, so the mirage theory cannot explain the lateral high speed movement of the objects reported by Arnold.

Menzel's fourth explanation was that Arnold saw orographic clouds which can assume circular shapes and often form in the lees (i.e., downwind of) mountain peaks. The clouds would, of course, be large but, as Menzel notes in his book, they "appear to stand more or less motionless." The lack of motion, as well as the lack of bright reflections, rules them out so, why did he even mention them? Also, Arnold would have realized they were just clouds as he flew past Mt. Rainier only minutes later.

Menzel's fifth explanation, wave clouds, is comparable to his first suggestion of "billowing blasts" of snow except that this time he proposed clouds of water vapor instead of snow. This explanation was supported by a photograph of such a cloud taken by a newspaper photographer. However, this explanation, too, fails to account for the very bright reflections reported by Arnold, for distinct semi-circular shapes and for the high lateral speed. Again, Arnold surely would have recognized a cloud as he flew past Mt. Rainier. In his third and last UFO book (written with Dr. Ernst Taves in the early 1970's, just before Menzel died), which is subtitled "The Definitive Explanation of the UFO Phenomenon," Menzel again discussed Arnold's sighting and offered his sixth (and last) explanation: Arnold saw water drops on the window of his aircraft. To support this explanation Menzel described a sighting of his own that turned out to be water drops that had condensed on the outside of the window of an aircraft in which he was flying. They moved slowly backwards from the front of the window. They were so close to his eyes as he looked out the window that they were out of focus and he thought they were distant objects moving at a great speed until, after a few seconds, he refocused his eyes and discovered what they were. In comparing his "sighting" with Arnold's Menzel writes: "I cannot, of course, say definitely that what Arnold saw were merely raindrops on the window of this plane. He would doubtless insist that there was no rain at the altitude at which he was flying. But many queer things happen at different levels in the earth's atmosphere."

Although no one would argue with Menzel's claim that "queer things" happen at different levels of the atmosphere, this fact is irrelevant. Had Menzel bothered to carefully read Arnold's report to the Air Force he would have seen Arnold's statement that he turned his plane sideways and viewed the objects through an open window to be sure that he was getting no reflections from window glass. (Fortunately Menzel did not propose water drops on Arnold's eyes!)


As fate would have it, a second witness saw the same objects as Arnold just as Arnold was losing sight of them near Mt. Adams. (Dr. Hynek evidently was not aware of this because he indicated in his analysis of the Arnold sighting that there were no other witnesses.)

In the latter half of August the Air Force received an unsolicited letter (12) dated August 20, 1947, which reads as follows (the errors in the original letter are preserved):

***** Sir. Saw in the portland paper a short time ago in regards to an article in regards to the so called flying disc having any basis in fact. I can say am a prospector and was in the Mt Adams district on June 24th the day Kenneth Arnold of Boise Idaho claims he saw a formation of flying disc. And i saw the same flying objects at about the same time. Having a telescope with me at the time i can asure you they are real and noting like them I ever saw before they did not pass verry high over where I was standing at the the time. plobly 1000 ft. they were Round about 30 foot in dimater tapering sharply to a point in the head and in an oval shape. with a bright top surface. I did not hear any noise as you would from a plane. But there was an object in the tail end looked like a big hand of a clock shifting from side to side like a big magenet. There speed as far as i know seemed to be greater than anything I ever saw. Last view I got of the objects they were standing on edge Banking in a Cloud. Yours Respectfully (Fred Johnson) *******

(Note: the Blue Book file page which contains this letter is labelled "A TRUE COPY" that was authenticated by Lt. Col. Donald Springer. I assume that the errors in the above letter were in the original letter and were not simply errors in copying.)

At this time during the summer of 1947 the FBI was actively investigating sightings, at the request of the Army Air Force, to determine whether or not any such reports could be part of subversive activities carried on by enemies of the United States. (The FBI ended these investigations, having found no evidence of subversion, in the fall of 1947.) Therefore, at the request of the Air Force, an FBI agent interviewed Mr. Johnson. He sent a copy of his report to FBI headquarters in Washington, DC, where a copy was found filed with other reports labelled "REPORTS OF FLYING DISCS, SECURITY MATTER -X." (Note: these are the real X- Files!) These reports were discovered when the FBI responded to a Freedom of Information Act request made in 1976 for any documents concerning flying saucers, UFOs, etc. The FBI found well over 1,000 pages of material relating to the Air Force investigation of UFOs, internal memoranda and sightings reported to FBI. The FBI report on Johnson's sighting (13) reads as follows (I have emphasized important statements):

******* (Fred Johnson, resident of) First Avenue, Portland (Oregon), reported without consulting any records that on June 24, 1947, while prospecting at a point in the Cascade Mountains approximately five thousand feet from sea level, during the afternoon he noticed a reflection, looked up, and saw a disc proceeding in a southeasterly direction. Immediately upon sighting this object he placed his telescope to his eye and observed the disc for approximately forty-five to sixty seconds. He remarked that it is possible for him to pick up an object at a distance of ten miles with his telescope. At the time the disc was sighted by Johnson it was banking in the sun, and he observed five or six similar objects but only concentrated on one. He related that they did not fly in any particular formation and that he would estimate their height to be about one thousand feet from where he was standing. He said the object was about thirty feet in diameter and appeared to have a tail. It made no noise.

According to Johnson he remained in the vicinity of the Cascades for several days and then returned to Portland and noted an article in the local paper which stated in effect that a man in Boise, Idaho, had sighted a similar object but that authorities had disclaimed any knowledge of such an object. He said he communicated with the Army for the sole purpose of attempting to add credence to the story furnished by the man in Boise.

Johnson also related that on the occasion of his sighting the objects on June 24, 1947 he had in his possession a combination compass and watch. He noted particularly that immediately before he sighted the disc the compass acted very peculiar, the hand waving from one side to the other, but that this condition corrected itself immediately after the discs had passed out of sight.

Informant appeared to be a very reliable individual who advised that he had been a prospector in the states of Montana, Washington and Oregon for the past forty years. *******

Mr. Johnson's letter to the Air Force indicates that he was in the right area at the right time to see the objects which Arnold reported. Johnson, just as Arnold had, reported that his attention was attracted to them by a reflection, presumably a flash of light on the rocks he was examining. He reported only five or six, but it is likely that he missed seeing the others as he concentrated on his telescopic view of a single one. (Also, he was recalling the event almost two months after it occurred, so he may well have forgotten some details, such as the exact number of objects.) Adding his estimated distance of the objects above him, 1,000 ft, to his estimated altitude, 5,000 ft, yields an altitude for the UFOs, about 6,000 ft, which is consistent with the altitude indicated by Arnold's claim that they were traveling "in and out" of the mountain peaks south of Mt. Rainier.

Johnson claimed that he watched one disc for 45 to 60 seconds. Assuming that they were traveling at the speed calculated previously, about 1,700 mph, in 45 seconds they would travel about 20 miles. Although it may have been possible that Johnson could see the objects over a distance of 20 miles from his location, it seems more likely that he saw them for less time. However, even if it were only for 30 seconds with his telescope, we may assume that he was able to discern many details that Arnold couldn't see, such as the point on the front and the "tail" waving side to side "like a big magenet" in the rear. (Here I presume Johnson is comparing it with the magnetic needle in a compass which swings left and right before reaching equilibrium.) He claimed that the objects were "round" and also "oval," thus generally agreeing with Arnold's description of nearly round objects (certainly they they weren't square or triangular or T shaped) and he estimated that they were 30 ft in diameter, a value that is smaller than Arnold's estimate and smaller than the previously calculated value, suggesting that Johnson underestimated the size. He also stated that the speed was "greater than anything I ever saw", which is consistent with the speed calculated from Arnold's sighting. He heard no noise. He observed that while the objects were in sight the needle of his compass waved from side to side. The waving stopped after the objects were out of sight.

The last statement in Johnson's letter provides important confirmation of Arnold's claim that he was able to see flashes of sunlight reflected from the objects. In the previous discussion of Arnold's sighting I pointed out that for the objects to reflect sun toward Arnold it would be necessary for some portion of each shiny object to tilt at least to an angle of about 450. This amount of tilt is supported by Johnson's claim that when he last saw the objects they were "standing on edge" while "banking in a cloud."

Aside from the apparent confirmation of Arnold's sighting, Johnson's sighting is unique as being the first to include a report of a physical effect during sighting (the apparent effect on the needle of his compass).

Dr. Hynek, in reviewing all the sightings for Project Grudge in 1949, did not offer an explanation for this sighting. Dr. Menzel, on the other hand, claimed to have explained it while analyzing the early sightings for his 1953 book. Menzel began his review of the sighting by pointing out that it occurred on the same day as Arnold's. However, he did not tell his readers that it took place at the same time in the afternoon, nor did he mention that Johnson was near Mt. Adams at the time and thus in the area where Arnold last saw the objects (flying past Mt. Adams). Thus the reader of his book would not have known, as Menzel probably did (Menzel had access to the Air Force files), that Johnson said he saw the objects reported by Arnold!

Menzel accepted Johnson's sighting as real (i.e., not a hoax, not a delusion), but explainable. After pointing out that Johnson observed the objects through his telescope for nearly a minute Menzel stated his explanation: "The behavior of the saucers... is distinctive enough to label them as probably a true sighting. Bright reflections from patches of clouds were the most likely cause."

One wonders how Menzel could seriously suggest that Johnson could fail to realize that the objects were merely clouds after viewing them for many seconds through a telescope as they traveled by rapidly and were last seen banking into a cloud. Menzel also dismissed the wobbling compass effect, arguing that in his excitement Johnson was not able to hold the compass steady. This is essentially saying that Johnson, who had about forty years of prospecting experience at the time, would not realize that the compass would wobble if he didn't hold it steady.

It is resoundingly not a tribute to science that Dr. Menzel's explanations carried a considerable weight with the scientific community. Scarcely anyone complained about his atmospheric explanations. Instead the book was complimented on bringing a measure of sanity to the field of flying saucer research. I helped establish the TRADITION which we live under today, that flying saucers/ufos, are all mistakes or hoaxes or delusions and certainly nothing to worry about. Note that TRADITION is important... so important that you could write a song about it! However, careful analyses sightings such as these by Kenneth Arnold and Fred Johnson show that this tradition is like a house built on sand... and it is crumbling.


  1. Daniel S. Gilmour, Ed., The Scientific Study of Unidentified Flying Objects, Chapter 5, Section 1; AFOSR contract study F44620-67-C-0035; Edward U. Condon, Director, 1968; Bantam Books Edition, New York, NY, 1969, pg. 481
  2. David. M. Jacobs, The UFO Controversy in America, Indiana University Press, (1975)
  3. Air Intelligence Report # 100-203-79, "Analysis of Flying Object Incidents in the U.S.," Directorate of Intelligence (of the Air Force) and Office of Naval Intelligence, 10 Dec. 1948; classified TOP SECRET until declassification on March 5, 1985; available from the Fund for UFO Research
  4. Edward J. Ruppelt, The Report on Unidentified Flying Objects, Doubleday and Co., Garden City, NJ (1956) and Ace Books, NY (1956)
  5. Donald Menzel, Flying Saucers, Harvard University Press, Cambridge, Mass., 1953
  6. Donald Menzel and Lyle Boyd, The World of Flying Saucers, Doubleday and Co., Garden City, NY, 1963
  7. Donald Menzel and Ernest Taves, The UFO Enigma, Doubleday and Co., Garden City, NY, 1977
  8. Documents found in the files of Project Blue Book at the National Archives
  9. Ted Bloecher, The UFO Wave of 1947, (NICAP, 1967) 30.) J. Allen Hynek, The Hynek UFO Report, Dell Pub. co, NY, 1977
  10. Kenneth Arnold, The Coming of the Saucers, privately published (1953)
  11. Kenneth Arnold, letter to the Army Air Force in the files of Project Blue Book (National Archives)
  12. Letter found in the files of Project Blue Book
  13. Document found in the files of the FBI released under the Freedom of Information and Privacy Act