Dr. Willy Smith:


On the night of February 24, 1959 a scheduled American Airlines flight from Newark to Detroit encountered three lights over Pennsylvania. The initial detection took place at 8:20 PM when the aircraft was 13 miles west of Williamsport. and the lights remained at about the 9 o'clock position for 40 minutes, providing an opportunity for many of the 35 passenger to observe them. They were also observed by the crews of two other planes flying much farther to the south, as well as by the tower operators in Pittsburgh. PA. 

The information content of this sighting is low, as all we have is three non-point lights changing relative position and separation, with intensity fluctuating from bright to fade-out and color variable from yellow-orange to brilliant blue white. 

The case made headlines and threw the Air Force into a frenzy, with an escalation of explanations which included the suggestion that those who report flying saucers--including Capt. Killian and his passengers-- usually had one too many. The refueling mission explanation was finally adopted; containing some attractive features, it was accepted by the press and the case passed into oblivion. However, a scientific and more detailed re-examination of the BB files shows that the Air Force was more eager to produce an explanation, any explanation, than to find out what really happened. 


The lights reported by Capt. Killian on February 24, 1959 were explained by Blue Book as having a very simple cause: a refueling mission. But we know after years of studying the files that the Air Force had a knack for picking out from all the tentative explanations the one that was practically impossible. This leads me to the following question: postulating that a mission was on that night: do the data provided by Capt. Killian and other pilots support that hypothesis? 

Before discussing the pros and cons for the reality of the refueling mission, we start with two pieces of information which so far have not been disputed, even by biased investigators like the late Dr, Menzel (Ref. 10) 

The first one is the statement by Capt. Killian that "the altitude of the objects was 30 degrees above my horizon" (Ref. 1). The second is the information that KC-97 refueling missions are flown at 17,000 ft. It is then easy to make an order of magnitude calculation to determine the distance "a" from the plane to the lights reported by Capt. Killian, without any precise knowledge of the exact position of the aircraft or the lights. We can assume with a small error that "a" is the hypotenuse of a right triangle in which the distance from the lights to the ground is h = 17000 ft. while A is the angle between the line of sight and the tangent to the horizon. 

We then construct the following table: 

The value A = 15 degrees was included because it is mentioned sometimes in the literature, as for example in Ref. 8, where one can find some rough attempt at a similar analysis. The other values are added for completeness, to show how little an error in angular elevation affects the results. 

The Refueling Mission Explanation

The third column expresses the distance from Capt. Killian's plane to the lights in nautical miles, which for none of the cases exceeds 35 nm. In other words, whatever the source was, it was not too far away, certainly not the almost 120 statute miles (104 nm) that would be necessary for the refueling mission to be seen from Capt. Killian's plane at 8:45 PM from the vicinity of Bradford, PA (Ref. 8, p. 117), and at about the same time (8:40 PM) be reported by the tower operators over Pittsburgh (Ref. 4). There is no doubt that a refueling mission was flown that night, but it was not what Capt. Killian saw, if the AF assertion that they are flown at 17.000 ft. is correct (Ref. 2) 

Another approach is to consider the resolution of the human eye, defined as the angular separation that must exist between two objects to be perceived as distinct. It has a value of a = 0.25 milliradians, and the linear separation d is obtained using the formula: d = aa, where a is the distance between the objects and the eye, 

The values in the last column of the table are obtained using that formula. But the fact is that the wing span of a B-47 is 116 ft., while for the KC-97 tanker it is 141 ft., so in all cases the lights of the planes would have been resolved and the aircraft positively identified. This was not the case, as all that was described by Capt. Killian and the other witnesses on Flight 139 were three lights in loose formation. Of course, if the planes were far enough away, the lights of each would have appeared blended into one, but the numbers in the table indicate that the distance required is of the order of more than thirty nautical miles, which does not satisfy the data. It could be argued that Capt. Killian committed a gross error in estimating at 30 degrees the elevation of the lights above the plane, but even if the elevation was only 10 degrees, the distance was about 16 nm and the lights would have been resolved. Moreover, we are told of three lights, not four, although there were four aircraft. The inescapable conclusion is that the refueling mission, if any, was either much higher and/or much farther away than stated. This is not possible either, as for the refueling both aircraft must decrease speed which can only be accomplished by decreasing altitude. The stated altitude of 17,000 ft. is in agreement with the design parameters of the aircraft involved. 

The same limitations on the distances are equally valid for the other aircraft reporting lights that night. For example, Capt. Yates' plane was too far south to see the lights of a refueling mission observed at the same time by Capt. killian. Yet he reported that at 9:00 PM something heading northwest crossed his flying path near Youngstown. OH (Ref. 8. p. 116). In addition. observers in the ground near Akron, OH reported lights moving east to west west at 9:15 PM (Ref. 8). from the official files we know that a refueling operation was over Pittsburgh at 8:40 PM, (Ret. 4) and a look at the map indicates that the three observations fit quite well; thus, what Capt.Yates saw and reported was very likely that specific refueling mission. 

Another negative aspect for identifying the lights seen by Capt. Killian and his passengers as aircraft is that the colors reported do not match what one would expect from the position lights of planes. Also. the lights were too powerful to be associated with jets. What made the explanation attractive, that is, until a more rigorous analysis is performed, is the relative motion of the lights, although Capt. Killian characterized it as too erratic to be jets 

Before he was silenced - and there is no question about that either (Ref. 9, p. 15) Capt. Killian provided quite a bit of information expanding on his original statements. In one of them (Ref. 9, page 3) he says: " At first, I estimated that the objects were not over a mile from us. This was just an impression: / be/ieve now that they were not that close". No. they weren't that close. but they were not very far away either, if we can trust the AF data about refueling missions! 

In this same interview Capt. Killian adds a numerical bit: "they appeared to be like the apparent size of the moon". Well, as everyone knows, the size of the full moon is 32' of arc or 9.3 milliradians; let's compare this with other statement made by Capt. Killian to Major Werkmeister many weeks after the facts (Ref. 3): the lights were each "the size of a quarter at arm's length". The diameter of a quarter is 7/8 of an inch, and the arm's length is ambiguous, but taking it to mean 30 inches, then the quarter subtends an angle of 29 mrad, i.e, three times the diameter of the moon, which I don't find credible. If we use those two values and calculate the diameter of one object at the distance of 5.6 nm corresponding to the reported elevation of 30 degrees, we obtain: 

moon size:                         d = 316 ft. 
quarter at arm's length:       d = 987 ft.

diameters which seem a bit too large, for had they been planes, with a constellation of lights to boot, at a distance of 5.6 nm the identification would have been immediate. Perhaps Capt. Killian was bad at estimating angular sizes, or perhaps he was trying to express that the lights were not point sources. But what is clear is that he did not observe a refueling mission near or far. 

The most damaging argument against the refueling mission hypothesis is the manner in which the AF changed its explications for the incident. In the first release (Feb. 28), the lights were the Belt of Orion, simply because Capt. Killian had used it as a model of what he saw. A few days later (March 1), some nasty remarks were made to the press about inebriation and UFO sightings (Ref. 11). And the third story was the refueling mission, released March 16, although the files show that the AF knew about it since March 2 at least (Ref. 4). 

Somehow the AF felt threatened by Capt. Killian's persistence that he had seen what he saw. After a point his statements to the press stopped, but his wife was not silenced, and she revealed that pressure had been exerted on American Airlines and that the company had ordered Capt. Killian to cease and desist, which he did. 

Other testimonies

The Blue Book files are silent about the testimony by other commercial pilots, and the information provided by other sources (Ref. 8) is not detailed enough for evaluation; besides, our purpose is to analyze the incident based only on the official information. 

The official files contain, nonetheless, a report that has some bearing on this matter. On the evening of February 2, 1959, about three weeks prior to the Killian incident, a distinguished professor at the University of Michigan and his wife were driving on the Ohio Turnpike near Sandusky. OH. The sighting was reported to the FBI in Detroit, which transmitted the information to the Air Force in Washington DC, and then to Selfridge AFB in Michigan, which in turn, passed it on to ATIC in Dayton, OH, on February 25, 1959. Evidently, on that precise date ATIC was not very receptive to any information supporting even remotely the Killian incident (Ref. 6). 

Curiously enough, the files contain only a retyped copy of the original FBI report (Ref. 7), where we learn that the witnesses described what they saw as a "yellow thing", which had an upper part much like the top of a sphere, while the lower part was rather level or flat. Other tantalizing details are provided, such as the presence of the silhouette of a conventional aircraft departing in the opposite direction. 

This report is relevant for at least three reasons: 1) the location is in the area of the 24 Feb. sightings, as shown on the map appearing on page 116 of reference 8; ii) because the witnesses are unimpeachable; this I know firsthand, as I was acquainted with the professor many years ago when I was a student at the University of Michigan; and iii) and perhaps the more important, the expedience with which the AF dismissed the incident without remorse (Ref. 6). 


The above discussion has shown that the incident described by Capt. Killian was almost certainly not a refueling mission, although it is easy to understand the irresistible appeal that such a solution had for the Air Force analysts, in their ignorance of the possible methods for testing its viability. It is a beautiful example of the underhanded techniques used by the Air Force to discredit reliable witnesses. 

The official explanation is therefore untenable, and the proper classification for this incident should have been "UNEXPLAINED". 

                    Dr. Willy Smith
                    UNICAT Project
                    November 10, 1992


The following documents are part of the BLUE BOOK FILES (RoIl 35) 

(1) Memo prepared by Capt. Killian dated February 24, 1959 with reference to Flight 139 and transmitted to the Air Force by AMERICAN AIRLINES.
This Memo has been reproduced many times, but often with the last paragraph omitted (Example; UFO EVIDENCE, p. 116). or with two paragraphs added emphasizing the refueling mission explanation (Example: enclosure in Ref. 5). The original document ends with the words "Distance away is unknown" and is not signed. The important item is: "The altitude of the objects was 30 deg. above my horizon."
(2) Letter addressed to Mr. Fred A. Kirsch dated 19 March 1959 and signed by Lawrence J. Tacker. Major USAF, Public Information Division.

Provides details about refueling missions, indicating inter alia that KC-97's fly at an altitude of 17000 ft. at 230 knots TAS. 

(3) Memo to ATIC dated 14 Aug.1959 and signed by R. F. Werkmeister, Major USAF. Administrative Officer.

This document reproduces (1) above, and adds a telephone conversation with Capt. Killian, where mention is made of the size of the lights [each individual light was the size of a quarter at arm's length]. It is also the first direct contact between the Air Force and Capt. Killian 

(4) Undated Memo addressed to ATIC Commander, Dayton, Ohio, signed by William D. Hostutler. Capt. USAF, Administrative Officer.

This document is in reply to a telephone call received at 08:20 on March 2, 1959, and confirms that at 20:40 hrs, 24 February (0140Z, 25 Feb.) three B-47's from the 772nd ACW Sq. were on a refueling mission near Pittsburgh, PA as reported by the tower operators. 

(5) Letter to Ms. Frances Ryan dated 24 June 1959 and signed by Lawrence J. Tacker. Major USAF. Public Information Division.

(6) Memorandum to ATIC Commander, Dayton. OH. dated 25 Feb.1959 and signed by P.E. Chancy, Major, USAF, Administrative Officer. 

(7) Memorandum to SAC by S.A. Coghlan dated February 4, 1959. 

Coghlan apparently was an FBI agent in Detroit. The document now in the BB files is not the original, but an unsigned retyped copy. 

Other non-official references.

(8) Hall, R.; THE UFO EVIDENCE, 1964, p. 116 and p.42 

(9) REPORT ON UFOs observed Feb.24, 1959 by AMERICAN-UNITED airline pilots. Compiled by Unidentified Flying Objects Research Committee, Akron. OH. undated.

This report is reproduced in toto in the Blue Book files 

(10) Menzel, Donald H. and Boyd, Lyle G: THE WORLD OF FLYING SAUCERS.

The final galley proofs of the pages dealing with the Killian case are part of the official Blue Book records. 

(11 ) "'Flying Saucers' Sightings Still Get Air Force Study", in the March 1, 1959 issue of the New York Herald Tribune under the byline of Ralph Chapman.