Donald A. Johnson


Some reports of UFO sightings involve events in which motorized land vehicles experience ignition or electrical system interference in the presence of a UFO; 276 such reports were collected from the UFO literature. These events were analyzed to determine the role played by position of UFO and distance from UFO to vehicle in the severity of the reported electrical system interference. A highly significant relationship (p  .001) was found between position of UFO and severity of effect. A substantial majority of the cases experiencing complete engine failures (stalls) occurred when the UFO was reported either directly in front of or above the witness' vehicle. A significant inverse relationship (p  .03) was found between reported distance from the UFO and severity of effect. A significant interaction between position and distance was discovered (p .04). UFOs appearing in front of or above the witness' vehicle were reported as being closer than those observed behind or off to one side. It was hypothesized that this interaction may be responsible for the correlation between position and severity of effect. Constructing a multidimensional contingency model to test for relative effects was not possible due to incomplete data. It was recommended that investigators of future events make a special effort to obtain distance and position estimates.

The analysis of close encounter cases of the second kind (CE-IIs), i.e., UFO cases involving reported physical effects, offer the potential of the richest rewards to scientific inquiry. Such cases offer the greatest promise for instrumental, quantitative data (Hynek, 1972). Even in cases where there are no lasting physical effects, it may still be possible to sort out physically meaningful information from the qualitative and general testimony of the UFO witnesses (McCampbell, 1976b).

Reports of motor vehicle electrical system interference during a UFO encounter usually involve no lasting physical effects or damage. However, there is one major advantage these reports have to reports involving simple close UFO observations: the presence of a physical device capable of serving as a measuring instrument, namely, the motor vehicle. McCampbell presents this argument in the following way:

A common lament in ufology is the lack of so-called hard, or instrumental, data. Such information is generally lacking in the sighting report. But it should bc observed that an automobile is merely an assemblage of components and circuitry that is reportedly responding to changes in the environment. In other words, the automobile functions as an instrument notwithstanding its design for other purposes. (1976, p. 164)

Viewed in this manner, the reported effect on the motor vehicle could provide us with the means to test certain hypotheses about the physical nature of the interference effect. An essential step is to notice the elements that are common to a large number of independent sightings.

The purpose of this paper is to investigate the role two variables -- position of UFO and distance from UFO -- play in the severity of the reported electrical system interference. These two variables were selected because they appear to have a role in the literature and because they relate to questions of physical causality of the reported effect.

Hall (1960) and McCampbell (1976b) both point to the same pattern in UFO ignition interference reports. The UFOs are reported as being directly ahead of the automobiles and at a low altitude at the time of electrical interference. McCampbell believes that this positioning plays a crucial role in headlight failures, and postulates that intense microwave radiation may be the cause. The radiation would collect on the headlight filament which would increase the resistivity of the tungsten in the filament, thereby reducing the flow of current and extinguishing the lights when the flow of the current becomes too low to keep the filament incandescent (McCampbell, 1976a). Position of the UFO would play an important role because the UFO would need to be within a narrow region directly ahead of the headlights in order for the microwave radiation to be focused by the parabola of the headlamp on the filament (McCampbell, 1976a).

Other hypotheses involving the possible effect of microwave radiation on the timing of the sparks in a standard ignition system vehicle and the resistivity of the tungsten alloy in the distributor points, are offered in explanation for the engine failures. Whether position would have any effect on the cause of these engine failures was not discussed by McCampbell. Nevertheless, there are a great many cases mentioned in the literature where engine failure alone is correlated with the UFO being directly in front or above the vehicle. We can hypothesize that a possible shielding effect occurs whenever too much shielding material (in the form of the roof, trunk, and passengers of the car) is positioned between the UFO and the engine of the motor vehicle.

This is only one hypothesis; other causal explanations could equally well be advanced. The intent of this paper is only to establish whether a statistically significant relationship exists, not to prove its causes.

If the cause of the interference effect is high frequency electromagnetic radiation, as McCampbell and some others contend (McCampbell, 1976a, then one should expect to observe an inverse relationship between distance and intensity of effect. This expectation would correspond to known physical parameters, such as the inverse-square law. McCampbell argues that such a relationship exists, and mentions some of the better documented cases which appear to reveal a graddational distance effect (1976a). On the other hand, Rodeghier (1978) could find no such relationship between distance and intensity of the interference effect in his analysis of automobile electromagnetic interference data. The lack of such a relationship could argue against a physical basis for the phenomenon, or it could be used to argue that the physical force involved is transient or only applied selectively. It is not clear, however, what type of statistical test Rodeghier applied to his data, or the number of cases on which he based his conclusion. An additional intent of this paper, therefore, is to determine whether proximity to the UFO at the time of the ignition interference plays a statistically important role in the severity of the effect noted.

A final intent of this paper is to shed light on the relative effects of these two factors by examining whether any interaction exists between position and distance, and what the strength of that relationship might be.


A computer-generated listing of all possible cases involving electromagnetic effects in the vicinity of a UFO and also involving a motor vehicle was obtained from the Center for UFO Studies' (CUFOS) computerized catalogue of UFO reports (UFOCAT) in November 1978. This listing contained 570 cases. Working from this and other sources, an eventual file of 276 cases was compiled that involved confirmed reports of motor vehicle ignition or electrical system interference attributable by the witnesses to a close UFO encounter.

These cases involved headlights and engine near failure and complete failure, but were limited to cases involving land vehicles and did not include reports of car radio interference. Because interference cannot be directly linked to a vehicle's electrical system, because it frequently results from a wide variety of mundane causes, and because the reports themselves were sometimes vague about the nature of the radio interference, it was felt it would be better to exclude these more ambiguous cases from the study.

Of the 276 cases, 154 were obtained from books or catalogues published by UFO researchers. The remaining 122 came from periodicals, newspaper accounts, and private investigators' files. Over 100 separate sources were consulted in compiling this file, and for the majority of cases, multiple references existed on the same report to check and compare. Table 1 breaks down the reports by their principal source.

While making no pretensions about this list being totally exhaustive, nevertheless it would be safe to say that due to the extensive nature of the search and the powerful bibliographic assistance provided by UFOCAT, this compilation contains the great majority of cases ever reported.

No discussion or exemplification of particular cases will be presented in this paper. For such a presentation, the reader is referred to Chapter 9 of J. Allen Hynek's book, The UFO Experience (1972).

Description of the Reports

The earliest reported case occurred in 1909 and the latest added to the file occurred in December 1978. Only seven cases occurred before 1954. Reports have been associated with every region of the world with the exception of Japan and the Far East.

Table 2 presents the number of reports for each major region of the world.

All cases were coded in terms of the nature of the effect on the motor vehicle and the type of vehicle involved. Categories of vehicle included 219 (79%) involving automobiles, 36 involving trucks or vans, 12 involving motorcycles, 8 involving farm vehicles, and 1 incident with a snowmobile.

These cases involved collectively over 500 witnesses. Perhaps surprisingly, over 60% of the cases involved multiple witnesses. The number- of-witnesses per incident data can be broken down as: single witness, 112 cases; two witnesses, 73 cases; three witnesses, 28 cases; four or more witnesses, 32 cases; information not given, 31 cases.

For types of electrical interference noted there were 83 incidents where both the engine and headlights of the vehicle died, 124 cases where only the engine was reported stalled, 9 cases where the vehicle had not been in operation but could not be started, 31 cases where the engine faltered and lost power but did not stall completely, and 29 cases where only the headlights failed while the engine performance was unaffected. With the exception of only 16 cases, all of these effects were apparently temporary and in some cases, power returned spontaneously once the UFO had left the area. In many cases, multiple vehicles were involved in the same incident. In particular, on two separate occasions a diesel-powered and a standard-ignition-powered motor vehicle were involved together. (The two cases referred to are the Forli, Italy case, occurring November 14, 1954, and involving two farm tractors, and the Fordingbridge, England case, occurring November 5, 1967, involving a diesel-powered Leyland truck and a Jaguar sports car.) In both instances, the ignition-system-powered vehicle stalled while the diesel-powered vehicle continued to run. For the record, no case involving the failure of a diesel-powered engine has ever been recorded, although at least two more cases involving diesel-powered trucks had reports of head light failures.


Of the 276 cases of ignition or electrical system interference reported in the UFO literature, a total of 176 contain some mention of the position of the UFO relative to the witnesses' vehicle. For these 176cases, the evidence reveals 86 cases (48.9%) where the UFO was reported directly in front of the vehicle at the time of ignition interference, 51 cases (29.0%) where the UFO was reported as hovering above the vehicle, and 39 cases (22.2%) where the UFO was reported as positioned behind or off to one side of the vehicle. Of 18 cases involving headlight failure alone, only 5 occurred when the UFO was directly in front of the automobile. This seems to contradict McCampbell's contention that "UFOs hovering directly overhead, standing or maneuvering off to the side, or chasing cars seldom, if ever, have killed the lights . . ." (McCampbell, p. 168).

A 3X3 contingency table was constructed comparing position of UFO with effect on vehicle's electrical or ignition system. Interference effects were categorized in decreasing degree of severity as (1) incidents where both engine and headlights failure were reported, (2) incidents where only engine failure was reported (obviously encompassing all daytime reports), and (3) incidents where the engine missed or slowed but did not stall completely or where headlights failure was reported. The results are presented in Table 3.

Clearly, a highly significant relationship exists between the reported position of the UFO at the time of the ignition interference and the severity of the effect. The strength of the reported effect appears to be greatly enhanced when the UFO is either directly in front or directly above the motor vehicle. This relationship is even more clearly shown by reducing the number of categories to a 2x2 contingency table. Effect is then categorized as "stall" or "no stall," and position categorized as "in front or above" or "other." This new categorization is shown in Table 4.

With one degree of freedom, the chi-square value is 14.98, indicating a highly significant relationship (p < .ooi). In terms of measures of association, the phi coefficient, which for 2x2 tables is directly translatable into a correlation coefficient, is equal to .31. This indicates a moderately positive relationship between position and effect, with approximately 10% of the variance observed in the ignition interference effect (whether the vehicle stalls or not) attributable to the position of the UFO vis--vis the witnesses' automobile, truck, or motorcycle.

We next turn our attention to the role that distance from the UFO plays in the severity of the ignition interference effect reported. It is well known among perceptual psychologists and other experts that humans are poor judges of distance, and our ability to estimate distances at night - when most of these incidents occur-is especially poor (Haines, 1979. Even under the best conditions, such estimates must be viewed as only rough approximations and not precise statements.

The difficulty in obtaining meaningful distance estimates probably discourages some witnesses from making any estimate at all, and probably further discourages investigators from recording and transmitting them. Only 56 cases contain an estimate (in feet or meters) of the distance from the observer to the UFO. This paucity of data is understandable.

However, estimates of distances, while only crude at best and certainly varying in accuracy from one observer to the next, can nevertheless provide some ballpark notion of whether the presence of the UFO was close by or far away. For this reason, reported distance in this study is treated as an ordinal variable with only three categories: close, intermediate, and far.

Close refers to all reported distances of less than 30 meters. In such instances, the observer should be able to rely on such distance cues as size and features of the UFO, as well as inter- positional cues, for instance, if the UFO was observed between the witness and a nearby tall tree. Such encounters are usually regarded emotionally by the witnesses as close and immediate, and very impressive.

An intermediate distance would be from 30 meters to 120 meters. More cases fall into this category than any other. The observer perceives the UFO to be a close but not overpowering presence, usually no more than a stone's throw away. Interpositional or size cues allow the witness to approximate the distance to be within the length of a large soccer field. A "far" distance would refer to anything beyond 120 meters.

The cutpoints for these categories were derived in part experientially as described above, and in part by looking at the data to derive categories of approximately equal size. To check for any spurious effects caused by the choice of cutpoints in the results reported below, the data were recalculated at cutpoints of 15 meters and 200 meters. Practically identical results were obtained. The ignition interference effects were dichotomized as either a complete engine stall or not. The results arc presented in Table 5.

An appropriate test of significance, more powerful than the chi-square test which makes rank order distance from close to far, is the nonparametic statistic called the Jonckheere test with tics (Leach, 1979). For our data, we will regard our explanatory variable (distance) as having the three ordinal values we discussed. We will treat every observation within a category as a tie. The test statistic, S, is the same as used in the Wilcoxon Rank-Sum test, and it is evaluated-- after a continuity correction is made--by approximation to the normal curve. Since our alternative hypothesis is that the data should conform to the "inverse square law" of effect over distance common to all physical forces, this will properly be a one-tailed test.

Our results show a significant relationship (p < .03) between severity of the ignition interference effect and the distance to the UFO. The likelihood of a vehicle stalling out consistently increases as the distance between the vehicle and the UFO becomes small.

As a measure of association, Goodman and Kruskal's gamma statistic was found to equal .48. This can be given a probabilistic interpretation by noting that the probability of a vehicle not stalling, given that it is further away from the UFO, is .74, while the probability that it would stall is 26. Gamma is then the difference of these two probabilities (Leach, 1979).

The logical next step in the analysis is to look for any interaction between position and distance which might further account for the association of both variables with severity of ignition interference effect. if no interaction is found, then we can conclude that each variable contributes to the interference effect independent of the other. If, on the other hand, a positive association between position and distance is found--"positive" defined in terms of close proximity being associated with advantageous positioning--then we must allow for the possibility that the position effect may only be an artifact caused by the proximity effect, or vice versa.

The test to use in this situation is again the Jonckheere test with ties. Since we are only interested in the alternative hypothesis that position and distance are positively associated, our test will legitimately be in the one-tailed direction only. The results are presented in Table 6 and we find that the relationship between position and distance is significant at the .04 level.

At this point we have conducted tests for all two-way interactions by summing over the third variable. Unfortunately, this method is not sufficient to allow any statements about the relative effects of position and distance on severity of effect. Indeed, to base our analysis solely on two- dimensional tables is risky, as situations of partial or conditional independence may arise where a two-dimensional treatment of the data alone could be misleading (Everitt, 1977).

The preferred course of analysis would have been to have developed a three-dimensional table of position x distance x effect. Such a multidimensional table would have allowed for testing the relative contributions of position and distance to severity of effect as well as testing for the possibility of a second order or three-way interaction. Unfortunately, due to a great lack in the number of distance estimates reported in the literature, the number of cases remaining in the analysis (N=52) is too few to perform such an analysis. With a 3X2X2 table, a chi-square test of mutual independence, with seven degrees of freedom, fails to achieve significance (Pearson's chi-square = 10.66, p < .20). One concludes that further analysis of the table would be unfruitful.


In reviewing the evidence for headlight failures only, we find that 13 out of i8 cases occurred when the UFO was situated somewhere other than in front of the car. It appears that we need to provide another causal model for these 13 cases, as McCampbell's tungsten resistivity hypothesis is not sufficient to explain all the evidence.

On the other hand, position of UFO seems in extricably linked to the phenomenon of vehicle electrical system failure. One hundred sixteen cases, or nearly two-thirds of those cases describing the position of the UFO, list it as directly in front or directly above the automobile. The criteria applied in coding these observations was quite strict and refers to a very limited area around the automobile: "directly in front" of the vehicle refers to exactly that, usually on or hovering low over the roadway and barring the way; "directly above" refers to the situation when the UFO hovers or passes directly over the hood or the roof of the car. Hall (1960) and McCampbell appear to have correctly alerted our attention to this relationship. Whether there exists a causal relationship between position and effect is difficult to assess, particularly since the position variable is confounded with proximity to the UFO. The position variable, however, might help explain those cases where a UFO passes in close proximity to a motor vehicle and no interference effect is noticed.

Distance and severity of ignition interference effect appear to have an established relationship in a manner compatible with what would be expected from a high frequency, electromagnetic force. The closer the UFO, the more likely the vehicle responds with complete engine failure. These conclusions are compatible with those observations of MeCampbell (1976a) but contradict those of Rodeghier (1981). A possible reason for Rodeghier's conclusions could be that his test simply lacked statistical power due to inappropriate design, small sample size, or the choice of the wrong test statistic.

The most attractive interpretation of the interaction found to exist between position of UFO and distance to UFO, from the point of view of someone who would like to show that a physical force is responsible for the engine and headlights failures, is the viewpoint that ascribes all of the interference effect to the close proximity of the UFO. The position effect is seen simply as an artifact of proximity and of no real importance. This argument would hold that since UFOs appearing in front of cars are actually closer, there is no great mystery in why more of these cars are stalling.

This view would be in accord with the results. It should be pointed out that the distance effect might still someday be accounted for by the position effect (or another variable not even considered here). Or, as is usually the case, the truth may be somewhere in the middle.

One criticism that might be made of the data and of UFO reports in general is that the events are not independent. Put another way, the possibility exists that the witnesses fabricated their reports or colored their own testimony so that it would be in line with the commonly "known" description of how a UFO should look and behave. Lack of independence violates a critical assumption of the statistical tests we have employed.

At least two considerations argue against this type of interpretation. First, I had hoped to show by including the data on region-of-world that the phenomenon is global in nature. Reports were contributed by witnesses from a wide variety of educational and professional backgrounds from just about every major cultural language group in the world. It is unlikely that witnesses in one culture would be familiar with testimony of similar events in other areas of the world, particularly when the news has to cross language barriers. Surprising as it may seem to those unfamiliar with the field of UFO research, the details of these events are simply not considered newsworthy by the international press. One must also keep in mind that it appears there is little that could be gained from fabricating a UFO encounter.

Second, a wide range of descriptions are obtained about such variables as color, size, shape, number of objects, the lack or presence of noise, as well as such subjective assessments as inferred intent on the part of the UFO. This seems to argue against the assumption that the witnesses are adopting a conventional story line.

An obvious direction for future research would be to compare ignition interference UFO events to other events involving UFOs with witnesses in automobiles where no electrical system interference is noted. Data for the variables position and distance would be compared.

In view of the findings of this report, it is recommended that all investigators conducting investigations of similar cases in the future make a special effort to obtain position and distance estimates.


Everitt, B.S. The Analysis of Contingency Tables. New York: John Wiley and Sons, 1977.

Haines, Richard F. Observing UFOs: An Investigative Handbook. Chicago: Nelson~Hall, 1979.

Hall, Richard H., editor. Electro-magnetic Effects Associated with Unidentified Flying Objects (UFOs). Washington, D.C.: Subcommittee of NICAP and UFO study groups of Cleveland and Akron, Ohio, June 1960. Published in limited quantity.

Hendry, Allan. The UFO Handbook; A Guide to Investigating, Evaluating and Reporting two sightings. New York: Doubleday, 1979.

Hynek, J. Allen. The UFO Experience: A Scientific Inquiry. Chicago: Regnery, 1972.

Leach, Chris. Introduction to Statistics; A Nonparametric Approach for the Social Sciences. New York: John Wiley and Sons, 1979, pp. 178-204.

McCampbell, James M. UFO Interference with Automobile Electrical Systems, in Proceedings of the 1976 CUFOS Conference, Evanston, III., 1976, pp. 164-182.

McCampbell, James M. Ufology. Milibrac, Calif.: Celestrial Arts, 1976.

Rodeghier, Mark. R. UFO Reports Involving Vehicle Interference. Evanston: Center for UFO Studies, 1981.

Source: 1983. Journal of UFO Studies, (old series volume 3).

This web page was created by Francis Ridge for the NICAP web site and the paper was the work of Dr. Donald A. Johnson.

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