NARCAP TR - 6, Part 2



   These difficulties may not in themselves be fatal, but they are significant, and adjusting the time sequence back or forth to compensate has the unsatisfactory effect of introducing damaging discrepancies elsewhere. This fact  invites reappraisal of some other elements of Klass's overall hypothesis. For example, he states that "McClure's records showed no signal for the five minute period between 5:30 A.M. and 5:35 A.M. [CDT - 1030-1035Z]", and argues that this correlates with the null between the two concentric rings of radar coverage formed by the main beam and lower sidelobe. But there is no suggestion whatsoever in the intelligence report that the signal disappeared during this time. (See para. 11 above. If Klass's curious interpretation were good for this entry then it would be good for others, with the result that there would have been no signal in the periods 1035-1038Z, 1052-1057Z, or after 1057Z - to cite but the more obvious - during which periods the aircraft was [ex hypothesi] well within the main beam coverage.)


   The conclusion that all the signal bearings "were pointing in the general direction" of Duncanville is also unacceptable without some reasonable explanation of errors as large as 40 degrees recorded by an experienced operator during straight and level flight. Was the aircraft axis periodically misaligned with its intended 265-degree course due to a drift to port which, perhaps because of faulty instrumentation, was never properly corrected? From the turn at Meridian through 1010Z the position and 265-degree course of the RB-47 can be guaranteed with some accuracy, being fixed by the known map coordinates of the visual event near Winnsboro, and it is a simple matter to show that a mean navigational error of about 20 degrees, applied consistently to port over the period from just before 1030-1042Z, would bring the aircraft to its point of turn somewhere S of Grapelands, Texas, adding several minutes to the existing discrepancy in the times of its passage through the Duncanville radar shadow. (If the southerly drift had begun before Timpson and nearer to Winnsboro, then the aircraft's eventual position and course would be still more problematic. It goes without saying that any substantial, sustained drift off course implies serious error on the part of the navigator and/or failure of numerous aids - magnetic, gyro and radio compasses, charts, clocks, driftmeters and so forth. A deliberate, premature departure from the flight plan to the south makes no sense in terms of a decision to pursue an "object" to the north; and of course a premature departure to the north - a possibility which will be addressed in a later context - is of no present help since it would increase the initial bearing error beyond even 40 degrees.)


   The effect of wind on the axial orientation of the aircraft is negligible during the 265-degree leg, since the eye of the westerly was only a few degrees off to starboard. But it can be noted that correcting for any minimal crabbing angle so induced has the effect of increasing the true error of the signal bearings from Duncanville, since the axis of the aircraft will be rotated into the wind (starboard) to maintain its heading. During the run NW the aircraft may have crabbed measurably to port since the wind would have been from a relative bearing of about 305 degrees, which would have the effect of reducing the measured error; but one would not expect this reduction to be significant in the context of a mean error of 35 degrees.


   The possibility that the values cited in the intelligence summary are errors of dictation or transcription is not very realistic. Such an error might occur once but it is not credible that a whole sequence of such values would be misreported, all skewed systematically in accordance with the independent qualitative description of the operator. There appears to be no good reason to question the competence or honesty of the operator, whose readings were (at least initially, and at the time of the largest "error") reportedly corroborated by  another ELINT officer and an electronically independent monitor subsequent to, and concurrently with, equipment checks performed on known ground radar sites. In short there appears to be no substantial likelihood of systematic error either in navigation or in the chain of detection, observation and reporting during this episode of the event, such as would be required to explain the reported bearing error.


   This leaves the possibility of random errors, periodically corrected, in the flight heading of the RB-47. Some deviations are naturally bound to occur due to microscale fluctuations in the windflow, but at 500 mph at 34,500', well above the lowland topography of Louisiana and East Texas on a summer's night, one would expect these to be small, brief, erratic, and certainly insignificant in terms of, for example, the mean 34-degree discrepancy carried from 1030Z past 1035Z. During the period up to the turn near Palestine at about 1042Z, the monitor(s) would have had about 45-50 separate "looks" at the signal.


   In summary there is a rough but persuasive congruence between the general area of Duncanville's S-band coverage and the general area in which very similar signals were detected, but the claimed accuracy of this match appears to be spurious. Certain anomalies remain unresolved, in particular the sustained gross discrepancies in signal bearing during the portion of the flight path which is most accurately known, and the problem of reconciling known times, speeds and positions of the aircraft with the radiation pattern in the vicinity of Duncanville.


  This latter point bears further emphasis: According to the intelligence report, just before 1050Z when the "huge light" was lost visually, the crew reported its position as 10 nautical miles NW of Fort Worth and this was "immediately confirmed" by Duncanville radar. At 1050Z the "object appeared to stop", the pursuing aircraft "overshot", Duncanville "lost object from scopes at this time" and McClure's monitor "also lost signal" for the first time. The position of the aircraft at this signal loss therefore appears to be fixed some few miles NW of Fort Worth. But according to Klass's interpretation, the Duncanville signal and the visual object had at this point already been reacquired when the aircraft had emerged from the radar shadow northeast of Fort Worth, 25 miles earlier on the track but one or two minutes later in time, having not overflown the light 10 miles NW of Fort Worth but (on his chart) passed a full ten miles to port of its position 16 miles NW of Dallas.


   If this sounds confusing, it is worth pointing out that, particularly from about 1050Z, confusion is by no means unique to Klass's attempt to make sense of the incident, as will be brought out later. The point is that the apparent relationship between the recorded data and the Duncanville pattern breaks down on examination: it is not confirmed by those data. It also bears emphasis that the implied relative angular motion of the source of the signal bearings (in particular from 1030-1042Z) is contrary to the relative motion of Duncanville, and it is only reasonable to admit that this behavior is consistent with what the intelligence report characterises as a "rapidly moving airborne source", a source which the flight crew believed was later in simultaneous visual and ground-radar contact. Therefore, notwithstanding the at-least-equally difficult problems that might be raised by any such hypothesis, the evidence directly and uniquely implicating the normal Duncanville FPS-10 signal can be said to remain somewhat ambiguous, and the possibility of abnormal circumstances (which may or may not be suggested by data we have yet to examine) should not at this stage be dismissed.


    The essential conclusion to be drawn from the aforegoing is that there appear to be latent errors in the reconstruction of the flight path. It is presently unclear where those errors may occur and what their magnitudes may be, and it is therefore also unclear what effect their correction would have upon the balance of negative and positive indications presented above. The reconstruction which we have considered (broadly following Klass) and which we have attempted unsuccessfully to refine is essentially based on dead reckoning from a single time-flagged map location assuming the assigned heading, approximate speeds, and the approximate time of an approximate point of turn. The course appears to be approximately consistent up to about 1050Z, but the indications of breakdown after this time suggest that it might have to be reworked if that breakdown cannot be mended by closer study.


The Final ECM Contacts, NE Texas & S Oklahoma


   As Craig was told by the crew in 1967, it was about half way around the turn W of Fort Worth that the now-familiar ECM signal was reacquired (just before 1052Z) with visual and ground radar contacts regained simultaneously. Chase and McCoid recalled to McDonald that they looked over their shoulders to see the object behind the plane, and continued to turn towards it while Chase requested ground permission to depart from his 34,500' altitude. The object appeared to be stationary, now at an estimated altitude of 15,000', and Chase put the plane into a dive down to 20,000', but at a range estimated at 5 miles the object once again disappeared visually, the signal disappeared from the ECM monitor, and the target disappeared from ground radar.


   The intelligence report supports these recollections quite closely, adding that the first signal bearing was 160 degrees (starboard aft), then at 1052Z "200 degrees relative bearing, moving up [the] D/F scope," that is to say advancing up the port side of the scope, which is broadly consistent with the reported position of the object behind the plane as its relative bearing would change during the port turn. At this time, now several minutes after overflying the object NW of Fort Worth at approximately 1050Z, the aircraft would have been turning S of Mineral Wells when it "began closing on object" to within an estimated 5 nautical miles, at which point the light disappeared at an estimated 15,000' altitude, and ground radar also lost their target. The aircraft would now have been coming back E into the area.


   It was at about this time that McCoid, having presumably asked Hanley (the navigator) for an update on the 'Howgozit' fuel consumption graph, became "a bit worried" and indicated to Chase that due to the departure from the flight plan and the use of extra power during pursuit they would have to turn for home, and so when contact was lost at 1055Z Chase informed Duncanville that they were heading N for Forbes. The intelligence report does not state (though it can be read as implying) that McClure's signal had also been lost when the the object disappeared visually and from radar on this occasion, but both McClure and Chase clearly recalled to Craig, and separately to McDonald, that this had occurred. However at 1057Z, two minutes after Chase had informed Duncanville of their departure for home, McClure regained the signal at a bearing of 300 degrees, indicating a source forward of the port wing at 10 o'clock. Since the aircraft would now be roughly SW of Fort Worth and evidently turning or at least preparing to turn N for home this would be in the general direction of Fort Worth, which is not inconsistent with the fact that 60 seconds  later Chase confirmed "visual contact with object approximately 20 NM northwest of Ft. Worth" at an estimated altitude of 20,000'.


   Klass's construction has the aircraft still westbound towards Mineral Wells at 1055Z, when the object disappeared for the second time, which is thoroughly inconsistent with the statements of the crew and the contemporary report that the aircraft was already turning back when it appeared for the second time. Three minutes earlier at 1052Z, Klass has the aircraft still heading NW directly away from Duncanville, which - on his own interpretation - is inconsistent with the report that the signal bearings were moving up-scope to port at this time. Again, his own interpretation itself requires that the aircraft had already turned back towards the SE when Chase dived to 20,000' in pursuit of this light (which Klass identifies as Rigel, rising at 105 degrees true in the ESE), but this occurred at about 1052Z when his chart has the aircraft still headed NW. By 1058Z, when Klass indicates that this second visual contact was first made prior to the attempted diving interception, the intelligence report states that this object had already long disappeared and the aircraft was turning N for home.


   The reasonable conclusion here is that Klass's attempted reconstruction is seriously flawed as to courses, times and distances flown, a conclusion which is already suggested by discrepancies on the earlier NW leg of the flight towards Dallas. The most serious confusion here arises from his misreading of the intelligence report. He states that from the initial disappearance of the "huge light" at 1050Z nothing at all was seen visually until the final light ("Rigel") was seen at 1058Z, and his belief that the diving interception occurred at 1058Z reveals the origin of this misunderstanding: he has confounded the two separate contacts at 1052 and 1058Z into an amalgam, and is further misled by what appears to be a typographical error in the report of the 1058Z sighting.


   The report states that at this time Chase "regained visual contact with object approximately 20 NM northwest of Ft. Worth, Texas, estimated altitude 20,000 ft at 2 o'clock from aircraft." A location NW of Fort Worth, or anywhere near Fort Worth, being unintelligible in terms of Klass's conviction that the light was Rigel in the ESE, he has elided this statement and fastened onto the ancillary detail that it was seen "at 2 o'clock", which he is able to approximately reconcile with his reconstructed flight path (saving that this, too, has to be fudged as will be shown later). But this reconstruction, which has the aircraft still heading SE then meandering into a starboard turn even further S in a diving pursuit of the light "at 2 o'clock", is plainly in error, and the aircraft was at this time (1058Z) positioning itself to depart N, having advised Duncanville of this necessary manoeuvre several minutes before. The declared position of this new object NW of Fort Worth therefore makes sense, being visible to the departing pilot off the port bow, and it is worth repeating that this position would also not be inconsistent with the ECM signal detected moments before at 10 o'clock from the aircraft. The likelihood is that "2 o'clock" is a transcription error, and it is not ruled out that it should have been 10 o'clock. (Note: Klass offers no specific defense on this point, but does elsewhere [source 199] opine that the intelligence report "contains two obvious errors, one of which may be typographical." He does not indicate them, however.)


   The above discussion turns out to improve Klass's argument in the sense that the up-scope signal movements at 1052Z can now be seen as occurring through the port turn W of Fort Worth, and thus W of Duncanville, so that the broad consistency of the signal bearings with a stationary object in the air somewhere behind the aircraft in the rough direction of Duncanville can also be said to implicate the FPS-10 at Duncanville. But the flight path during this turn cannot be exactly plotted, and the axis of the aircraft co-ordinate system will be tangential to this curve so that its attitude now becomes a significant variable. Neither the Duncanville hypothesis nor the "UFO" hypothesis is therefore testable in respect of these bearings.


   However, when the RB-47 was heading N from the Dallas area towards Forbes AFB, some 20 minutes after the turn S of Fort Worth, yet another signal was picked up which, in McClure's opinion, was due to the Duncanville radar. From about 1120Z the bearing remained off the tail between 180 and 190 degrees until 1140Z when the aircraft was "approximately abeam Oklahoma City", at which point the signal "faded rather abruptly." Why McClure regarded these signals as distinct from those detected earlier is somewhat unclear, but in 1971 he responded to Klass's explanation of the case saying: "I know that once we were near Dallas and [heading] North towards Forbes, the signals were undoubtedly CPS-6B/FPS-10 air defense radars. I do not believe any UFO was emitting these signals." Indeed he had said as much to Craig in 1967:


Limited fuel caused the pilot to abandon the chase . . . and head for his base. As the pilot levelled off at 20,000 ft. a target again appeared on number two monitor, this time behind the B-47. The officer operating the number two monitoring unit, however, believes that he may have been picking up the ground signal at this point. The signal faded out as the B-47 continued flight.


   The times cited are approximately consistent with the FPS-10 pattern at 20,000' for a groundspeed of about 300 mph which would bring the aircraft to approximately Sulphur (about 60 miles S of Oklahoma City) as it exited the lower sidelobe. Presumably Chase had reduced power to conserve fuel, and he did recall that the signal had been lost in southern Oklahoma even though the navigator, Hanley, corroborated the intelligence report, saying that it was not lost until they were right up to Oklahoma City. McClure was unable to recall exactly. Howsoever a mean bearing of 185 degrees is persuasive and the overall match is not unreasonable.


   At this stage the ambiguities in the evidence appear irresolvable. There remains a very strong case for the Duncanville FPS-10 as the source of the signals in terms of the general area of detectability, frequency, period and pulse pattern, and that the FPS-10 output was detectable appears to be confirmed by the operator's opinion that he was receiving it, at least after about 1120Z. A rough correlation of signal bearings with the location of Duncanville can be argued for the periods 1051-1055Z, and 1120-1140Z.


   On the other hand the relationship with the FPS-10 pattern is not without anomaly. The reported location of the aircraft at the time of the initial disappearance of the "huge light" and concurrent loss of ground radar/monitor targets at 1050 is specifically fixed as being close to a position "10 NM northwest of Fort Worth", this being where the "object appeared to stop and aircraft overshot". This has been shown to be consistent with times and bearings along the subsequent flight path, but is clearly inconsistent with the Duncanville radiation pattern since it permits no signal loss at all concurrent with passage through the zenithal radar shadow and indeed requires signal loss to occur when the aircraft has re-entered the main beam. Also the correlation of the 1057Z  signal with Duncanville is doubtful, the probable flight path at this time arguing for a bearing several tens of degrees away from Duncanville. Prior to 1050Z the bearing error is not only greater than can easily be explained but is inversely correlated with the bearings to Duncanville in a manner not symptomatic of electromechanical failure. The ground speed required to get the aircraft from its initial turn SE of Duncanville to Klass's signal-loss location at the required time is grossly excessive, even if this location were to fit the radiation pattern, which it does not; but the actual recorded location of this event, which is a far worse fit still, would require an even more excessive speed based on the assumed location of the turn. Therefore some major reconstruction of at least this portion of the flight path prior to 1050Z is clearly in order on any hypothesis, with results that are presently unpredictable.


   For the moment it would too much to say that the Duncanville hypothesis has irretrievably broken down, but in its simplest form it no longer looks in very good shape, and it is fair to say that the immediate cause of the anomalous signal bearings remains uncertain. At the same time there is for most of the duration what appears on the face of it to be a provoking correlation between the pattern of signal acquisition, motion and disappearance, and events observed visually and by ground radar. Klass believes these concurrent radar-visual events to be explainable in terms of a civil aircraft, two astronomical objects and coincidence. It is to these matters that we now turn.



The Visual and Ground Radar Contacts


   The initial visual sighting occurred at 1010Z during the west leg in the vicinity of Winnsboro, NE Louisiana, before McClure had mentioned the anomalous up-scope signal detected back in S Mississippi. Chase, up front, was the first to spot what he said he at first took to be a rapidly approaching jet with its landing lights on. But it appeared to be at or above their own 34,500' altitude. The "very intense" bluish-white light continued to close fast from about the 11 o'clock position, and Chase called McCoid's attention to it. No navigation lights were visible. At that point Chase warned the crew over the interphone to make ready for a sudden evasive manoeuvre, but before he could take action the light appeared to change direction and shot across the nose of the aircraft at extreme speed to a position which Chase recalled as about 2 o'clock and which the intelligence report refines to "2:30 o'clock". Both men watched the passage of the light and saw it disappear at this point. During the following interphone talk, McClure then brought up the odd radar signal in Mississippi.


   Klass suggests that this object was a fireball meteor, its apparent proximity and change of direction being illusions. This is certainly possible and not without precedent. Interestingly it appears that Blue Book initially explained the very similar "buzzing" of American Airlines flight #655 near El Paso, Texas, on the same night (0330 MST/0930Z) as a fireball, but then changed their minds in favour of flight #966 which had recently departed El Paso for Dallas and would (according to Klass) arrive there at about 1050Z in time to play the role of UFO for the second time on the one trip, as we will see. But the "brilliant green" object or "huge green UFO" which "shot" eastwards past flight #655 on its westward approach to El Paso, appearing out of a clear sky "without warning" and causing the Captain to execute a violent manoeuvre which injured 10 passengers, certainly sounds more like a fireball than another Douglas DC-6. The ambiguous sensitivity of the dark-adapted eye to shades of blue and green is well known, and it would be tidy if this incident and the RB-47 sighting 530 miles away could be explained by the same eastbound fireball.


   The alpha Capricornid radiant would have been low in the SW sky, and although only the outermost fringe of this shower (July 18 - 30) could have been entered on July 17 its meteors do tend to be slow and bright, even though it is not noted for fireballs. (The alpha Cygnid radiant, the other main shower visible during July, would have been far too high in the sky at over 75 degrees terrestrial elevation.) It would not be the first time that pilots have been misled by the sudden brilliance of a fireball into grossly underestimating its range. Unfortunately the fixed times make this impossible, leaving us with either of two somewhat improbable scenarios: two separate fireballs leading to two similar near-collision illusions for two different flight crews within an hour; or one fireball, plus flight #966 which appeared once as a "huge green" UFO near El paso then again (according to Klass) as a "huge red" UFO near Dallas/Fort Worth.


   The next visual sighting of the object in the NW apparently 5000' below the RB-47 at 1039Z, and which Chase pursued in his turn towards the Dallas area, is ascribed by Klass to the star Vega, which he describes as being "brilliant" at a true azimuth of 300 degrees and an elevation of 27 degrees. When the action got closer to the Dallas/Fort Worth area Chase and McCoid started looking at flight #966 in approach to land at Love Field, Dallas, having presumably transferred  their attention from Vega at some point. When flight #966 landed, disappearing visually and from ground radar, the RB-47 overflew its position, banked into a port turn to bring it back over the area, and "regained visual contact" just as ground radar "regained scope contact", but an attempt to close on this object was foiled by another simultaneous radar-visual disappearance. Klass offers no interpretation of these events. But a final light was seen as the RB-47 was beginning its turn N for home. This time, argues Klass, they were looking at the star Rigel. Firstly let us consider the flight #966 hypothesis in the context of the reported radar-visual evidence.


   The event, or sequence of events, for which Klass offers no interpretation is actually of central importance, but due to his misconstruction of the intelligence report (indicated earlier) he allows the reported ground-radar contacts to recede to a single target which appeared "briefly" only once and was, he believes, misinterpreted in "the excitement of the moment". Further, he states that this contact only occurred "according to the crew account", and that it was subsequently denied by the Duncanville commander in a report to ADC with the statement: "HAD NEGATIVE CONTACT WITH THE OBJECT." Rather than "question the veracity of the crew report" Klass proposes that this target, reported briefly just before the over flight and ECM/visual disappearance at 1050Z, was American Airlines flight #966 approaching Love Field, Dallas, ETA 1100Z. Its landing lights would explain the "huge light" which the RB-47 overflew, and as it dropped low on final approach it would coincidentally have disappeared from Duncanville radar. If this target had been identified later as this civil DC-6, then "the commander might be too embarrassed to admit the error and could try to dismiss his station's involvement with a brief  'HAD NEGATIVE CONTACT WITH THE OBJECT.'"


   This ostensible denial is indeed brief, and seems little with which to fill the three pages of report data transmitted by TWX from Duncanville to Air Defense Command Headquarters some four hours after the event. The context of this phrase, which Klass explicates as meaning that no UFO "had been sighted on the radarscopes - at least the one the RB-47 had been chasing", is therefore unclear. However the report of the incident compiled at the instigation of the Director of Intelligence, Headquarters, Air Defense Command, by the COMSTRATRECONWG 55 Wing Intelligence Officer almost a month later was in no doubt that Duncanville ADC radar had scope contact with the "object", and this information was passed to Blue Book by ADC without any denial. Indeed, the information in this report could hardly have been denied since it was based, not on assertions "according to the crew", but on real-time, on-board voice recordings.


   From at least 1048Z (possibly a little earlier) when the ground-radar episode was just beginning, the officer operating the RB-47's #3 monitor, Walter A. Tuchscherer, was "recording interphone and command position conversations". What this means is that the associated equipment designed to record hostile military communications intercepted by this monitor, as well as time-referenced navigational data from the flight deck for post-mission analysis, was now switched on by Tuchscherer and had begun recording the on-board interphone conversations of the crew as well as the radio talk between Chase, in the "command position", and the Duncanville ADC radar controllers. This was evidently the recording which Chase remembered being removed from the aircraft by intelligence personnel when they landed, and equally evidently it informed the report compiled by those personnel.


    Having stated that ECM #3 had now (1048Z) begun recording, that report goes on:


ADC site requested aircraft to go to IFF Mode III for positive identification and then requested position of object. Crew reported position of object as 10NM northwest of Ft. Worth, Texas, and ADC site Utah immediately confirmed presence of object on their scopes.

  At approximately 1050Z object appeared to stop, and aircraft overshot. Utah reported they lost object from scopes at this time, and ECM #2 also lost signal.


   According to Klass, flight #966 was at this time on final approach to the Dallas, Love Field runway with its landing lights on. But according to this report the "object" was the best part of 30 miles away NW of Fort Worth. If flight #966 was not yet on final approach, and was 30 miles away, it would not have had its landing lights on; and if it was on final approach at Dallas with its landing lights on at 1050 (ten minutes before its ETA) when it disappeared from the radar, it would have to have flown at about 900 mph to reach Love Field in the maximum of two minutes since radar "confirmed" its position NW of Fort Worth. Furthermore the object which the RB-47 was pursuing had been initially sighted 11 minutes earlier at 1039Z, appearing then as a "huge light" at 2 o'clock from the aircraft which was then about 100 miles SE of the over flight area (based on the "pursuit" speed of Mach 0.83), and flight #966, approaching this area from the west at, say, 200 mph, would have to have been some 50 miles further away at this time. It is safe to say that, even had its landing lights been unaccountably on at this time, flight #966 could not have appeared as a "huge light", let alone a "huge, steady, red glow", from a range approaching 150 miles. (Klass realises this, which is why he suggests that Chase and McCoid were initially pursuing the star Vega.)


   Klass's model is furthermore internally inconsistent, inasmuch as he indicates flight #966 approaching Love Field being "overflown" by the RB-47, but at the same time indicates the RB-47 on a heading which never passes within 10 miles of it; this makes no sense in terms of the "pursuit" of the "huge light", and still less sense when the aircraft, supposedly having then drawn abeam of the object 10 miles away, rather than turning starboard to correct its approach turns even further away to port and proceeds westwards N of Fort Worth before finally turning back near Meridian some 70 miles from Love Field. This course does, however, make sense if the aircraft is pursuing an object NW of Fort Worth as stated in the contemporary report.


   If the luminous radar target which disappeared at 1050Z had been flight #966 landing at Dallas, however, then it evidently would not explain the luminous radar target which reappeared a couple of minutes later. Klass's exposition here passes on to examine the ECM signals newly acquired by McClure to the rear of the plane at this time, but omits all mention of any further ground radar contact and concurrent visuals, giving particular emphasis to the seemingly damaging contention that "the flight crew had not been able to reacquire visual contact with the light . . . Nor did the unidentified target show up on the Duncanville radar scopes." However, this and the ensuing phase of the incident are recorded in the intelligence report in terms which fully support the recollections of all of the crew that ground-radar, visual and ECM monitor contacts were regained almost simultaneously at this time: "About half way around the turn," Craig was told in 1967, "the target reappeared on both the  monitor and ground radar scopes and visually at an estimated altitude of 15,000 ft.", and McDonald noted that "All of the men recalled the near-simultaneity with which the object blinked on again visually, reappeared on the #2 scope, and was again skin-painted by ground radar at site Utah", shortly to be lost yet again in another simultaneous radio-optical disappearance when Chase attempted to intercept it. "Whenever we'd lose it, we'd all lose it," insisted McClure in 1967. "There were no 'buts' about it, it went off." The 1957 intelligence report, compiled with the aid of recorded intercom and radio traffic between the aircrew and the Duncanville radar site, confirms:


Aircraft began turning. ECM #2 picked up signal at 160 degrees relative bearing. Utah regained scope contact, and aircraft comdr [and copilot] regained visual contact. At 1052Z ECM #2 had signal at 200 degrees relative bearing, moving up his D/F scope. Aircraft began closing on object until the estimated range was 5NM. At this time object appeared to drop to approximately 15,000 feet altitude, and aircraft comdr lost visual contact. Utah also lost object from scopes.


   It is certainly true that the ground radar returns, taken alone, are not able to be evaluated, and in another case the bare report of targets gained, lost and regained would be of little interest. Here, however, a flight crew's report of a visually unidentifiable light was "immediately confirmed" at the given position, which suggests at least a prima facie likelihood that radar and visual observations were of the same object, as Klass is evidently moved to concede. But at this point the idea that flight #966 could be the culprit is already strained for the reasons we have discussed; when the radar-visual disappearance happens to coincide with loss of the ECM signal detected at the object's bearing, due to the aircraft's passage out of the FPS-10 beam, the strain increases; when contemporary records indicate that the plane was at this time, on the contrary, flying deeper into that beam, the strain begins to tell; when visual, radar and monitor contacts are all then regained simultaneously, with no flight #966 now in the air, coincidence is pushed to breaking point; and when contact is yet again simultaneously lost visually, on ground radar, and (according to the crew's testimony) on the monitor, the hypothesis of coincidence must surely collapse.


   There appears to be one possible unifying explanation of the ground/air electronic synchrony. If the Duncanville radar was in fact tracking the RB-47 in the belief that it was the "UFO" then coincidence would no longer be needed. As the plane left the radar coverage its blip would disappear and the onboard ECM monitor would simultaneously lose the radar signal; then as the aircraft turned it could re-enter the radar coverage, its blip would reappear on the Duncanville scopes and the ECM signal would be reacquired. Unfortunately this is untenable. Firstly this offers no explanation for the concurrent visual losses and reacquisition; secondly, radar target and ECM signal loss at 1050 is inconsistent with the westbound flight NW of Fort Worth away from the inner null zone in the radiation pattern; and thirdly, Duncanville had ensured "positive identification" of the RB-47 by requesting that its transponder be switched to send a unique IFF identity code which would distinguish it on-scope from any other target. Having done this Duncanville "immediately confirmed presence of object on their scopes" at the reported visual location.


   The use of IFF here is of some importance. IFF Mode 3, as requested by Duncanville, was the transponder mode for joint civil/military aircraft identification (as opposed to the classified military uses of modes 1 and 2 and a  separate mode for altitude report) and is still designated as such in modern SSR radar systems which evolved from the IFF principle. IFF is a dedicated system separate from the surveillance radar output, exchanging space-coded pulses at frequencies around 1 gigahertz in the middle of the UHF region between an interrogating transmitter piggy-backed on the ground radar and an active transponder in the aircraft. According to the intelligence report, Chase "requested all assistance possible" from Duncanville shortly before 1042Z, but it appears that it was not until around 1048Z that Duncanville "requested aircraft to go to IFF Mode III for positive identification and then requested position of object." Klass finds it suspicious that "despite the light traffic at that early hour [Duncanville] asked Chase for assistance in locating the UFO," presumably  suggesting that they could see nothing substantial until Chase encouraged them to hunt for a target. But this is inconsistent if what they then did "immediately confirm" was the very-substantial American Airlines DC-6 coming in to Dallas on its routine bread-and-butter run from El Paso. This blip, approaching a nearby major airfield in the manner of dozens of identical blips week in week out, should have been straightforward to identify in 6 minutes - if not by interrogation then by simple familiarity - and a delay suggests not that ADC personnel were watching flight #966, so dumbfounded by this "UFO" as to forget for six minutes that the pursuing RB-47 pilot was waiting for "all assistance possible" in order to intercept it, but that they had quite other problems.


   Given that flight #966 was somewhere on-scope, as it presumably should have been since we know that that it left El Paso, the Duncanville operators would doubtless have noted it in response to Chase's preliminary report that he was in pursuit of a UFO in the area, but it would probably be promptly identified, which explains why they did not report back to Chase that they had a "UFO" target on-scope. The operators would be looking for an uncorrelated target to correspond with Chase's quarry in order to begin giving him vectors to intercept, and in order to give this assistance they would need to know the instant position of the RB-47. If they had an uncorrelated target and the RB-47 on-scope this would not be a problem, so the reasonable inference is that at least one of these targets was not on-scope at that time. Now the most obvious target on-scope in conditions of "light traffic" should have been that due to the B-47 bomber hurtling straight towards the area at maximum throttle, yet despite having radio contact with the pilot the operators were so uncertain of the location of the RB-47 even after several minutes that they requested positive identification by IFF Mode 3. Whatever else was or was not displayed on the scopes it is plain that the primary need was not "assistance in locating the UFO", but assistance in locating the RB-47. Why should Duncanville have had this problem? The answer is that the RB-47's northwesterly pursuit past Duncanville had taken it through the zenithal radar shadow above the site, and for several minutes it would itself have been undetectable.


   At about 1048Z when Duncanville confirmed a target at the location 10 miles NW of Fort Worth, approximately over Lake Worth, the closing aircraft would only just have been approaching the point of emergence from the radar shadow and an object moving ahead of the aircraft (at a visually estimated range of 10 miles according to Chase) and at lower altitude would have emerged a little sooner. When Chase had first contacted Duncanville at about 1040Z the aircraft would have been some 70 miles SW of this point of emergence (based on a ground speed of 530 mph, true airspeed 553 mph - Mach 0.83 - wind 50 mph from 300 degrees relative) and would still probably have been on-scope to the SW of Duncanville, approaching the null inside the main beam coverage which  would begin at a ground range of 37 miles from the site. It would not be on-scope for long, however, and an object an uncertain distance ahead of the RB-47 could already have been inside the shadow cone at this time. When, quite shortly after this, the RB-47 blip itself disappeared as it entered the radar shadow, the operators would have been watching the scopes for the uncorrelated target, doubtless noting the inbound scheduled flight on its low-altitude approach NW of Dallas and checking it out. They would have had a plot of the RB-47's NW heading when contacted by Chase, confirmed no doubt by his voice report to them and possibly also by his prior call for permission to the CAA Air Traffic Control Center at Dallas, so that the operators would have a fair idea of where and when to expect its re-emergence. But meanwhile they evidently had no assistance to offer for several minutes as the RB-47 continued through the blind zone overhead. (Note: this perhaps explains Klass's objection that "the [Duncanville] commander denied that a UFO had been sighted on the radarscopes - at least the one the RB-47 had been chasing." Initially, and for several minutes, they would indeed have had "negative contact with the object" which the RB-47 was chasing, and this context interprets an otherwise puzzling remark.)


   Then at about 1048Z, just after Tuchscherer began recording voice traffic at his #3 monitor position, something happened to prompt a query from Duncanville. If a target had then been seen emerging out of the shadow to the NW of the site the operator would need to know if it was the RB-47, and the sure way to identify it would be to request the aircraft to transmit its IFF recognition signal. The operator radioed Chase and asked for "positive identification" by IFF Mode 3; Chase complied, and when the target, now heading to the N of Fort Worth, did not display the recognition signal the possibility would arise that this was the "UFO". Consequently Chase would be asked for the estimated current location of the object, which he gave as 10 nautical miles NW of Fort Worth, and "ADC site Utah immediately confirmed presence of object on scopes." A minute or so later the pursuing RB-47 would itself probably have been painted emerging into the pattern, its transponder signal identifying it as it followed the unknown NW. At this time, recalled Chase, "he began to sense that he was getting closure at approximately the RB-47 speed" and at the same time Duncanville informed him "that the target had stopped on their scopes". He veered the aircraft slightly to avert any danger of collision but found that he was coming over the top of the object, visible below at a depression angle of about 45 degrees. At 1050Z it disappeared "like throwing a switch", Chase overshot, "Utah reported they lost object from scopes at this time, and ECM #2 also lost signal."


   Note that this construction of events interlocks closely with the times and positions relative to Duncanville and Fort Worth for which other arguments have been put forward above. And note particularly that the course of the aircraft through the Duncanville shadow cone immediately prior to 1050Z appears to be confirmed by this internally consistent interpretation of Duncanville's actions at this time. If this is correct then the obvious implication is that the 3000 mHz radar signal being detected by the RB-47 up until 1050Z was not due directly to the Duncanville FPS-10.


   The evident correlation of these and subsequent radar/visual events is rather persuasive evidence of some unusual phenomenon or combination of phenomena. The least one should reasonably conclude is that the report is not convincingly explained by American Airlines flight #966.


    The object seen at 1039Z apparently 5000' below the aircraft's altitude, which Chase had turned NW to pursue, could not even optimistically be interpreted as flight #966, as Klass realised. He therefore tentatively adopts the explanation, suggested by Rober Sheaffer, that this light was the star Vega in the constellation Lyra. Quoting Sheaffer's description of Vega as "a brilliant star, brighter than the first magnitude" he suggests that although an experienced flight crew would not normally mistake a star for a UFO, given the earlier "fireball" and the signal now being detected by the back-end crew they would be "anxious" and "searching for visual contact." At 1039Z Vega would have been about 30 degrees to starboard of their course (1 o'clock), which is perhaps not unacceptably far from the crew estimate of 60 degrees (2 o'clock); but it was at an elevation of 27 degrees, and at no altitude does an aircraft close its distance from a star sufficiently to diminish its angle of elevation! At 34,500' Vega was still 27 degrees above the aircraft's level wing. (Note: the wing would be level unless Chase was already starting a tentative starboard turn towards the light, in which case the angle of bank would increase the apparent elevation above the wing.) Experiments and case-studies demonstrate a marked tendency for even experienced observers to grossly overestimate elevation angles, in addition to which the psychological effect of relating one's judgement to the ground below from an altitude of 6.5 miles would probably be to further exaggerate the estimated elevation. Thus there is no clear reason why a bright but unspectacular star (visual magnitude +0.14; for comparison the star Sirius at -1.58 is almost 5 times as bright, and Venus, which is commonly described as "brilliant", can be more than 50 times as bright) at fairly high elevation almost a third of the way to the zenith should be singled out in the NW sky as a "huge light" 5000' below the aircraft


   Exactly how or when Vega became confused with flight #966 remains obscure. There is no suggestion in the witnesses' testimony or in the intelligence summary that there was anything vague or fugitive about the "huge light" which Chase turned to follow: it was "pursued", "pulled ahead" and appeared to hold a ten mile range in the "perfectly clear" cloudless sky. But at some point, according to Klass, Chase and McCoid ceased looking up at Vega - which would now have been almost dead ahead in the middle of the windshield and compelling enough to appear as a "huge light" - and began looking down at the landing lights of flight #966. According to his own model this transfer of attention must have occurred some time earlier than 1050Z, when the RB-47 flew over the position of flight #966, and, also according to his model, it must therefore have occurred southwest of the position at which the simultaneous ECM signal loss occurred as a result of the plane exiting the FPS-10 radiation pattern. Thus, even with Vega invoked, flight #966 cannot have been closer than about 50 miles away when observed; at this minimum range it would be on top of Dallas airport and would have landed long before the RB-47 got anywhere near it; and, of course, if the RB-47 had got anywhere near it the ECM monitor could not have been receiving the Duncanville signal. Added descriptive details offered by the crew make this scenario even less tenable: the light was a "red glow", a "huge, steady, red glow" which "appeared to emanate from top of object". Vega's elevation of 27 degrees exceeds the critical mirage angle by a factor of fifty, and exceeds even the maximum angle for extreme scintillation by a factor of two. There were no clouds in the NW. Vega therefore could not appear red. DC-6 landing lights are not red.


   When the aircraft had later begun to turn for home at 1058Z after the final radar-visual disappearance the flight crew observed another light, construed as  the same "object", at a position given as 20 nautical miles NW of Fort Worth, apparently at the same 20,000' altitude as the RB-47. As earlier discussed this position is dramatically inconsistent with the cited relative bearing of "2 o'clock", as viewed from any point on the flight path, but the night was "perfectly clear" and the crew reported that they could see "the lights of cities and burn-off flames at gas and oil refineries below" which would be useful pilotage points to confirm Hanley's navigational reckoning. It seems probable that Chase and McCoid knew well enough where they were in relation to Fort Worth, and since on any possible reconstruction of the course a 2 o'clock bearing would at all times since the original approach from Meridian have been on the opposite side of the aircraft from Fort Worth, one is forced to conclude that the figure "2" is an introduced error (possibly mis-transcribed from a spoken "ten" on the ECM #3 recording). However Klass elects to accept this bearing, discounts the declared position NW of Fort Worth without explanation, and mysteriously indicates the "apparent position" of this light some 50 miles SSE of Fort Worth, arguing that it was probably the star Rigel given "an unusual appearance" by some clouds in the south.


   The aircraft "was heading southeast" and Rigel "was in the southeast at an azimuth of 105 degrees" visible at 2 o'clock from the aircraft, argues Klass. But this is a little fudged, since Rigel, at 105 degrees azimuth, was not SE but barely S of E, and if anything it would appear to port (N) of an aircraft on a SE heading, thus nowhere near 2 o'clock, which is 60 degrees to starboard. In fact there is no reason to suppose that the aircraft was on a SE heading, as has been indicated. However at the time of this sighting "Utah had no scope contact", which it presumably should have had if the same "object" was really 20 miles NW of Fort Worth at 20,000'. There is no indication of how long this object was in sight, whether it moved, what it looked like, or how it disappeared. This final sighting therefore remains unresolved for want of information.


Queries and Conclusions


   It is evident that a precise time-flagged plot of the RB-47's off-course movements in the Dallas/Fort Worth area would be the only means of certifying the existence or otherwise of a relationship with the Duncanville FPS-10 radiation pattern. And any original navigational records, wire-recordings, radarscope photographs and so forth which might establish such a plot will, equally evidently, never be available. The course as sketched in the ADC data sheet some weeks after the event by Chase, from which McDonald derived his reconstruction, differs markedly from that favoured by Klass and reportedly refined in correspondence with Chase in 1971. Klass's model can at least be tested, however, inasmuch as it is required to interlock with his FPS-10 hypothesis, and there are seen to be significant timing inconsistencies.


   Considered alone such inconsistencies might not be damning, but in the context of the whole they are irreducibly at odds with times and events which are either fixed by the record or which can be reasonably inferred. To further labour one example, Klass's model requires signal loss at 1050Z to have occurred some 30-40 miles south of Duncanville, coincident with the over flight of an American Airlines DC-6 some 10 miles north of Duncanville, which is clearly impossible and furthermore inconsistent with the contemporary record, which tells us that this over flight occurred somewhere NW of Fort Worth. Klass attempts to elide the difficulty by not indicating the location of the RB-47 at 1050Z since,  on his own model, ECM signal loss at this time could not be consistent with the Duncanville radiation pattern. If one accepts half of the hypothesis, coupling the 1050Z signal loss to the radiation pattern but forgetting about trying to fit in flight #966 (perhaps there was some other large light source 30-40 miles south of Duncanville), then the whole thing comes uncoupled at the other end because the signal was reacquired in about 1 minute (about 1051Z), which cannot be squared with the time required to cross at least 50 miles of radar shadow (the minimum between brief upper sidelobe contacts). If the Fort Worth location is a gross error (perhaps in debriefing or transcription), and the RB-47 therefore did not have to cross the zenithal radar shadow but made its turn to port due south of Duncanville and thus quickly re-entered the radiation pattern nearby, then it could not have been anywhere near Mineral Wells at 1055Z, requiring a further error in the record.


   On the other hand the documented location of radar/visual/signal loss NW of Fort Worth, 60 or 70 miles away, is consistent with the sequence of subsequent events during and after the turn in the direction of Mineral Wells, with the actions of Duncanville ADC including the delay in providing radar assistance and the need for IFF identification of the RB-47, with signal bearings indicating a source in the rough direction of Duncanville from about 1052Z, and with CAVU conditions favourable to good pilotage which would hardly permit confusion between the small towns of the Texas prairies and the lighted conurbations of the Dallas/Fort Worth area. It seems very significant, if bewildering, that signal loss at this location is also grossly inconsistent with the Duncanville radiation pattern.


   This schedule is therefore self-consistent from 1050Z, but still fails to explain the immediate cause of the FPS-10-type signal detected when the RB-47 should not have been directly illuminated by the FPS-10 at Duncanville. It may also not have escaped notice that it is of no help in removing the timing discrepancy between the assumed 1042Z turn from a 265-degree heading and the aircraft's arrival in the Fort Worth area at about 1050Z. When considering Klass's chart of the flight path excessive ground speeds were found to be required during this NW run, which was one of the anomalies which prompted a re-evaluation of his scenario. Therefore, although both Klass's scenario and the present one are about equally embarrassed by this discrepancy and its resolution is not probative in respect of either, it clearly still needs to be addressed, since it has been argued that the initial heading and speed of the RB-47 on its west leg from the area of Meridian are rather well established up until approximately the point of turn. To find out the magnitude and direction of any adjustments that would be required, and to consider whether any are justifiable, it will be necessary to look at this point again in detail. And if any adjustments were both justifiable and useful, how would they affect earlier conclusions about the correlation or otherwise of the 1030-1050Z signal bearings with the bearings to Duncanville?


   Given that the 1050Z over flight location was in the area of Lake Worth one is now in a position to work backwards from a second time-flagged map position towards the first, 1010Z near Winnsboro, Louisiana (actually 32 degrees 00 minutes N, 91 degrees 28 minutes W, about 10 miles east of the small town of Wisner). The straight-line distance between these two points is approximately 325 miles on a heading of about 280 degrees, passing approximately over the top of Duncanville and requiring a mean ground speed of about 487 mph; but we know that this distance has to be increased by an initial heading of 265 degrees followed by a turn to the NW. A position for this turn can, as we have seen, be  extrapolated by assuming a constant Mach 0.75 (about 450 mph) on 265 degrees, which is supported by the intelligence report's statement that only at the time of this turn did Chase "increase speed to Mach 0.83"; but the required mean speed thereafter becomes excessive. Chase, however, recalled that he actually varied speed before the turn in an attempt to change the relative bearing of the signal source, which nevertheless remained constant to starboard. The exact time of this exercise is unknown, but could have been during the period 1030-1035Z, just after the signal was acquired, when the intelligence report shows a negligible variation between 70 and 68 degrees. Whether the mean effect was to retard or advance the aircraft is unknown, but there is the possibility of some latitude in the mean true ground speed at this point.


   Is it possible that Chase actually altered course slightly, too, with the same experiment in mind? When the "huge light" appeared visually off to starboard at 1039Z in roughly the same direction as the signal it would certainly be psychologically consistent if Chase had elected to veer a little from his assigned course by this time, an "unofficial" outing in the interests of mounting curiosity. After all, the likelihood of interfering with any other traffic at 34,500' would be negligible, the night was "perfectly clear", their assigned turn for home near Waco, Texas, would be coming up shortly, and a little premature nudge towards the north might do no harm. When, according to his statement to McDonald, he "overcame his reluctance about calling attention to these peculiar matters" and sought official CAA permission to "ignore flight plan and pursue object", it would not be surprising if he was in fact already somewhat north of the position actually required by that flight plan, now prudently seeking retrospective sanction for a course of action to which he was already committed. By 1040Z when, according to the intelligence report, he received that sanction, one can well imagine that Chase was already inching the RB-47 further to starboard in anticipation, keen to keep the "object" in his sights. And by 1042Z, when he officially "increased speed [and] turned to pursue" he might have been putting on power and coming out of a turn that was already well underway from a start position some miles north of his assigned course. The cumulative effect of a small deviation of this kind over several minutes could well be significant, and could explain why Chase reached the Fort Worth area somewhat earlier than he "should" have done.


   Circumstantial evidence for something of this kind is found in the map of the flight path which McDonald derived from Chase's original 1957 sketch, which does indeed indicate a slight starboard drift beginning west of the Louisiana/Texas border, easing into a less acute turn. Notwithstanding the evident scalar and geographical approximations in this map, this qualitative feature may thus be significant; and given that time needs to be found somewhere on any hypothesis, save the one that the whole report is a tissue of inexplicable yet fortuitously interlocked errors, a premature off-course trend towards the "object" - which is psychologically and tactically plausible - should probably be accepted as the only reasonable explanation.


   However, one immediate effect of slightly "straightening out" the bend in the course by such a deviation is to bring the NW pursuit heading of the RB-47 even closer to a diametric crossing of the Duncanville radar shadow, increasing the duration of the anomalous FPS-10-type signal. That is to say the aid which it supplies to the timing with the one hand it removes with the other, and there appears to be no evading this difficulty. The only course adjustment which would reconcile the anomalous signal with the radiation pattern would be to locate the  point of turn more than 100 miles further on, about due south of Fort Worth in the area of Waco, with a subsequent heading due N passing to the W of Fort Worth and thus avoiding the zenithal shadow; but needless to say this bears no resemblance whatever to the course as recalled by the crew, as sketched originally by Chase, as reconstructed by Klass, or as allowed by the timing. To have reached Waco by about 1042Z would require a mean air speed of some 630 mph during the 32 minutes since Winnsboro, or about 25% greater than that declared, which is inadmissible; the match between the 1030Z signal acquisition and entry into the Duncanville lower side lobe is thereby destroyed; Waco was the scheduled point of turn for the mission, but the intelligence report confirms that an unscheduled "off course" turn was cleared with CAA Air Traffic Control; and the speed required for the N leg to Fort Worth would also remain excessive.


   A second effect of the inferred starboard departure from a 265-degree heading is to rotate the true signal bearings clockwise during the period from commencement of the drift to the turn proper at 1042Z. The bearing errors from Duncanville will therefore change unpredictably by an angle equal to the difference between the true instant heading and the assigned heading of 265 degrees. Since the extent of this (possibly inconstant) difference is unknown, one can do no more than indicate the gross tendency: if the deviation had begun prior to 1038Z (as it probably should have done in order to become substantial) then the large (order of 35 degrees) positive error recorded prior to this time would be increased; but the relatively small negative error from 1038Z through 1040Z (about 8-15 degrees) would be decreased; and the widening negative error after this time would also tend to be slightly decreased. These changes would probably not be large - only a few degrees - and the overall percentage inaccuracy would probably not be much altered; but it is noteworthy that the bearings to Duncanville during a creeping turn could be moving up-scope, and - especially if the turn proper were commenced prematurely - the up-scope movement of the signal between 1030Z and 1042Z would then no longer necessarily be inconsistent (qualitatively speaking) with the Duncanville signal.


   Thus far, then, there is nothing lost and a great deal gained in terms of overall consistency by proposing that Chase tentatively anticipated his official clearance to depart from the flight plan. Some improvement in the match between signal motion and the relative bearing of the Duncanville FPS-10 is achieved, and it becomes possible to get the RB-47 to the Fort Worth area by 1050Z at reasonable speed. But the immediate origin of a signal which was not lost until 1050Z remains unexplained.


   Three further anomalies remain to be mentioned. When Roy Craig first interviewed McCoid and McClure in 1967 he was told that the RB-47 navigator, Hanley, had received returns on his airborne radar (as opposed to the emitted signals which McClure was detecting) from a target at bearings coincident with those of the visual object, the signal on the passive monitor(s) and the ground radar target. Chase did not recall this and Hanley, on active service in Vietnam at the time, was not available to be interviewed. However the contemporary intelligence report contains no mention of airborne radar contact. McDonald did later reach Hanley by telephone, and although the former's exposition of the case indicates that Hanley's minimal input was supplementary to more exhaustive interviews with the principal participants, it is nevertheless noteworthy that it contains neither confirmation nor denial; McDonald makes no mention whatever of airborne radar contact. In view of these facts little weight can be attached to the recollections of McCoid and McClure, although it is fair to point out that  Craig's summary draws attention no less than five times to the importance attached by them to this issue.


   Then there is the brief appearance at 1040Z and again at 1042.5Z of a second signal on the #2 monitor: on each occasion McClure had a signal at 40 degrees relative bearing, each time consistent with the trend indicated by bearings immediately before and after; but additional signals were both times displayed for a short period at 70 degrees, a wide departure from the trend. As Klass points out, the ALA-6 manual cautions that weaker secondary signals can sometimes be displayed due to scattering of radar energy from an efficient ground reflector. Curiously the 1957 intelligence summary states that at 1040Z when McClure reported having two signals on-scope "Aircraft comdr and co-pilot saw these two objects at the same time with same red colour." Equally curiously neither Chase nor McCoid had any recollection of having seen more than one object simultaneously, and none of the men, including McClure, recalled the simultaneous appearance of two signals on the monitor. In the first interviews with Craig in 1967, however, McClure did recall that on more than one occasion the signal source abruptly disappeared and reappeared at a different bearing before returning, and McCoid agreed that there were simultaneous abrupt dislocations of the visual object, possibly explaining the 1957 statement. If this explanation were correct then the secondary signal - whose strength of presentation is unfortunately not described in the report - would have been displayed not concurrently but alternately, and thus would not be adequately explained as a reflection. However, evidence of another cause is not wholly persuasive and the issue remains unresolved.


   A final point concerns the signal characteristics originally determined by McClure's ALA-5 pulse analyser back in Mississippi and which, according to the intelligence report, were exactly the same as the characteristics of the signal later detected over Texas. On the first occasion McClure had not made a permanent record, but when the signal appeared a second time over Texas he wrote down the exact characteristics: the pulse length was once again 2 microseconds, which is twice the length of the 1-microsecond pulse from a CPS6B/FPS-10 radar. This could indicate that radar energy was reaching the monitor by two routes - direct radiation and secondary reflection - the longer path length of the latter resulting in its delayed arrival. If this reflected path length is 984 feet (0.186 mile) longer than the direct line of sight then the reflected energy will arrive exactly 1 microsecond later and cause smearing of the detected pulse to 2 microseconds. Such a reflection could be due to energy incident on the ground around the radar site, but would be a transient effect sensitive to small local variations; a 1-microsecond smear would not be expected to be constant between one site and another and over ground distances of many tens of miles with considerable changes of slant range and elevation. If the signal detected over Texas did indeed have the same 2-microsecond pulse length as that detected in Mississippi, therefore, and especially if it remained at 2 microseconds, the probability of smearing due to ground-incident energy would be very small indeed. This discrepancy is thus possibly significant but not probative. (Note: one might speculate here that this was one symptom which caused McClure to differentiate between the "UFO" signal and the normal ground radar signal - presumably with a 1 microsecond pulse - which he believed he was detecting during the flight home towards Forbes.)


   To try to weigh and summarise the implications of all the aforegoing is a daunting prospect. Happily there is no one scenario totally consistent with all the  evidence, which relieves one of the burden of having to marshal any final proofs. It will be sufficient to indicate a few salient conclusions, invite attention to the more obvious residual anomalies, and indulge in some brief speculation. Some conclusions are:


1) The most detailed, ingenious and influential attempt to explain the ground-radar and visual observations (Klass 1974) is unsatisfactory on a number of counts. Specific arguments leading to this conclusion have been offered in their place, and one should also consider the cumulative improbability of a scenario involving four different, consecutive visual misinterpretations (five, counting the episode which Klass overlooks) together with coincidental, simultaneous radar-visual acquisition or loss on three different occasions.


2) The radar signals detected by the ELINT monitor(s) are very similar to - if not proveably quite identical to - the output of CPS-6B or FPS-10 ADC radars.


3) Evidence that such a source may have been operating in S Mississippi is at best ambiguous, but an FPS-10 is known to have been operating at Duncanville, Texas, and during the later events the RB-47 would for much of the time have been in a position to detect the Duncanville signal. (Note: according to Air Defense Command records checked by Klass no other CPS-6Bs were operating in the South Central region and three other FPS-10s - all in Texas - were out of range of the action near Dallas.)


4) The bearing and motion of the Mississippi signal are difficult to equate with the probable position of the aircraft in relation to a CPS6B which might have been operational at Keesler AFB.


5) First detection and final loss of the Texas signal are broadly congruent with the maximum drum of the Duncanville FPS-10, but the bearings to the source are at certain times inconsistent to a degree requiring explanation and the signal was retained for a significant period at times when the RB-47 cannot, on any workable reconstruction, have been flying within the FPS-10 vertical-center radiation pattern.


6) Apart from two brief episodes which can possibly be interpreted as ground reflections, the ALA-6 never displayed two consistent signal sources which could correspond to both the FPS-10 and, simultaneously, a second emitting or reflecting "UFO" source.


7) The core radar-visual episode from approximately 1039-1055Z is unexplained but consistent with the observation of an unidentified object or phenomenon which was a periodic emitter and reflector at optical and radar wavelengths respectively. During this episode ALA-6 signal loss and reacquisition was also repeatedly simultaneous with air-visual and ground-radar indications in a manner which cannot be explained.


   Point 7 summarises the most puzzling features of the entire sequence and warrants a few more words. If the conclusion to which it appears to point is accepted for the sake of argument, then we have an object which was visually observed in the rough direction of Duncanville, pursued in the rough direction of Duncanville, overflown when it stopped so that it then appeared behind the aircraft in the rough direction of Duncanville, and finally reacquired after the turn, again appearing in the rough direction of Duncanville. Plainly this is all generally consistent (quantitative discrepancies notwithstanding) with the rough relative bearing of Duncanville, and put thus appears to be a strong prima facie case for Duncanville as the source of signals which were believed to relate to the "object". But the bearings are also roughly consistent with the reported motion and positions of an object which was seen visually and tracked by ground radar in the area, and these elements of the case put a deal of strain on the prima facie interpretation. Given that the contemporary USAF intelligence investigation of the case carries any weight at all, it is worth reminding oneself at this point that, based on interrogations and records studied at the time, the Director of Intelligence of the 55th Strategic Reconnaissance Wing concluded with "no doubt" that "the electronic D/F's coincided exactly with visual observations by the aircraft comdr numerous times, thus indicating positively the object being the signal source."


   The movements of this putative "object" as pursued in the rough direction of Duncanville, stopping, then being overflown by the RB-47 on another roughly radial heading away from Duncanville, before being reacquired in the turn and re-engaged during a second inbound pass, are reasonably natural and consistent (uncertainties about exact courses and positions notwithstanding). And if this scenario were correct then it is entirely possible that the bearings to the "object" and to Duncanville would at all times coincide within the practical limits of resolution of the ALA-6 monitor. If this were the case then the monitor display(s) would fail to discriminate between the direct signal from the FPS-10 itself (when this was detectable) and a reflected or re-radiated FPS-10 signal received from the "object". This obviously invites description as a coincidence, but if one might hijack Klass's defense of his own scenario one can observe that coincidences do happen. One might also be tempted to add that an "object" followed in the direction of Duncanville then lingering in the vicinity - as indicated by concurrent air-visual and ground-radar reports - is an elegant, economical and intelligible explanation of that coincidence, whereas the several coincidences required by Klass not only fail satisfactorily to address the radar-visual evidence but are collectively less elegant, less economical and less intelligible.


   Neither scenario directly explains the radar signals detected for several minutes during transit of the radar shadow, unless one proposes that a "UFO" was emitting simulated FPS-10 pulse trains with a simulated 15-second period. Of course this is possible. Klass objects that "a spaceship from another world" outfitted with a "large, powerful" FPS-10 radar "simply to play mischievous games with the RB-47" would have caused "intense" interference on terrestrial radar scopes, but this is really word-play: given the premise, the emitter would not have been built by General Electric! It would not necessarily be large, or powerful, or omnidirectional; variable tuning over a couple of dozen mHz is a well understood earthly technique of minimising mutual interference between adjacent similar radars; and the concept of mischief is anthropomorphic. Nevertheless the underlying point is well made and one hesitates to address the implications of this startling idea.


    One can more comfortably accept that, in both scenarios, this circumstance could be said to indicate what we might neutrally call abnormal propagation conditions in the FPS-10/RB-47 environment. Anomalous propagation (AP) as normally understood does not seem to apply here, since during the portion of the flight in question the elevation of the aircraft from Duncanville moves from a minimum of 9-12 degrees (normal top edge of main beam coma lobe or upper side lobe) through about 30 degrees (on Klass's model) or more (assuming the slightly revised course discussed above). AP due to abnormal vertical gradients of refractive index such as commonly occur in the stratified calm air of a summer night is minimal at grazing angles as high as 10 degrees, and subrefractive upward bending of ray paths by a further 20 degrees or more is out of the question in terms of conventional theory. It is believed by some radar meteorologists, however, that there may exist atmospheric layers or more discrete structures with very extreme refractivity gradients and power reflection coefficients which are close to or above the threshold of detectability, by sensitive radars, even at near-normal incidence. Therefore although such phenomena may currently be at or just beyond the horizon of atmospheric physics, some analogous structure cannot be ruled out in this case.


   In this regard, the distinguished Chicago University radar meteorologist Dr. David Atlas wrote in 1970 that "while some of the UFO observations require almost incredible atmospheric structures for their explanation on the basis of [radar] propagation phenomena . . . I fully expect that these still incredible atmospheric structures will be found to be entirely reasonable some years hence when our observational capacity can demonstrate their existence." [Sagan & Page 188] Almost all of the propagation phenomena which are really well understood at present are anisotropic in the vertical plane and of some lateral extent - that is, they are due to layers of refractive discontinuity forming roughly parallel with the surface of the earth. Sometimes high reflectivity coefficients occur due to dielectric inhomogeneities associated with atmospheric turbulence in the clear air, particularly in the 20-40,000' altitude region where the turbulence can disturb aircraft, and these layers have been found to show fine structure such as hexagonal convective cells, thermals, travelling waves and even "breaking" waves. It is legitimate to suppose that other phenomena analogous to hydrodynamic boundary effects may occur rarely, and that some of these may be dynamically stable, localised, and possibly often mobile along the interface (one thinks here of eddies and standing waves). The limits of extreme local abnormality in the atmosphere have presumably not yet been discovered, and one thinks back to the contentious models proposed by Menzel in the '50s and '60s in which extraordinarily discrete atmospheric "lenses" were assumed to be responsible for radio/optical "UFO" mirages of a degree and nature so incredible as to be roundly dismissed at the time by atmospheric physicists across the attitude-spectrum from academics such as McDonald to USAF weather specialists.


   If one were free to hypothesise an "incredible structure" to account for the phenomena observed over NE Texas in 1957, one would be tempted to suggest that the microwave output from a primary source - the FPS-10 - was somehow being refracted due to a secondary phenomenon analogous to a discrete "bubble" or "lens" of sharp refractive discontinuity, which also perhaps refracted a reddened visual mirage image of city lights. This structure would be required to have high specular reflection efficiency in the 10-centimetre region to present as a ground-radar target, but probably only at incidences on the order of 80 degrees from the normal, and certainly a refractive "lensing" effect of enormous efficiency at incidences closer to the normal so as to intercept and, as it were,  "duct" the low power density in the zenithal radar shadow which would be present due to leakage of the FPS-10 output into minor vertical lobes. Its optical image appeared to be below the aircraft, suggesting the possibility of a physical locus which would be in a region of power density higher than that irradiating the aircraft in proportion to the square of its proximity to the transmitter; but the aircraft may have been within the lensing layer, detecting weak radar energy focussed along its upper boundary by a mechanism qualitatively analogous to (although quantitatively unlike) Raman brightening. (Such a position within the layer could be consistent with the presence of ground returns on the airborne radar via the same path, although its low power would make these less likely and it seems probable that no such returns were received.) Thus during the RB-47's transit of the shadow the "lens" would not have the reflectivity to return these weak pulses to the ground radar, but would perhaps continue to gather and focus them into a signal detectable by the ALA-6. The radio "blurring" incurred during this process could perhaps account for the smearing of 1-microsecond pulses into 2-microsecond pulses.


   This structure would therefore have the properties of: 1) specular reflection of detectable 10-cm radar pulses; 2) refraction of weak 10-cm energy with extreme efficiency suggestive of amplification by the focussing/interference of radar wavefronts; 3) extremely efficient refraction/reflection (presumably of city lights) at optical wavelengths, tending to the red end of the spectrum; 4) visual and radar behavior approximating that of a discrete domain exhibiting continuous apparent movement, generally ahead of the aircraft in the manner of a receding rainbow but at least once showing apparent closure to a steep visual depression angle followed by radio-optical disappearance, then reappearance for an episode of apparent near stationarity. In all cases the understood maximum grazing angles would appear to be exceeded by a very large margin, and it is safe to say that no such structure is presently known to atmospheric physics.


   The foregoing is not offered as an explanation of the case but merely as an indication of the kind of form which a unifying explanation might be required to take if projected from current knowledge. It is merely picturesque as it stands and clearly constitutes no solution, but "incredible" is of course the very definition of future knowledge, and in that future the spectrum of available explanatory options is always widening. The simple dichotomy "explained-or-alien" is a response to an invalid question, and cases such as this graphically illustrate the wisdom of funding what Hynek called our "poverty of hypotheses", even at the risk of borrowing beyond our security.


   In conclusion, whilst there are features of this report for which conventional explanations of varying probability can be suggested individually, the resulting structure is inelegant, unintelligible, cumulatively highly improbable, and most importantly glosses over central features for which no explanation exists. In particular the radar-visual episode near Dallas/Fort Worth invites interpretation in terms of a novel aerial phenomenon, and it is only even-handed to point out that the simultaneous radio-optical disappearances at this time seemed to relate to the approach of the pursuing aircraft on two separate occasions in circumstances which (due to the evident range and altitude differences) are probably not interpretable as due to the mixing and disruption of an atmospheric structure by the passage of the aircraft. The reported movements of the object can generally be interpreted as reactive to the presence of the aircraft in a manner analogous to evasive, rational action. Although strictly speaking there is insufficient information on the radar aspects of this case, it would be churlish to deny the existence of some suggestive evidence of unusual phenomena, and the case should therefore still be carried as an unknown pending further study.


[ADDENDUM. This analysis was prepared without the benefit of knowing the very extensive and detailed work of Brad Sparks which addresses some of the same issues raised here. In particular the issue of the Biloxi radar and the apparent anomaly in the charted flight path. Sparks' research appears to have established, consistent with the time-distance-bearing arguments discussed above, that the Biloxi radar was not in fact operational. The upscope signal is therefore not only anomalous in behavior (for an electromechanical ambiguity) but appears to lack an obvious conventional source. Sparks' study of the flight plan also provides independently a convincing rationale for a course deviation essentially the same as that hypothesised above on time and distance grounds, which considerably strengthens the inference drawn here that the claimed correlation between the UFO signal(s) and the Dallas area radar pattern is probably unsound. See: Brad Sparks, RB-47 RADAR/VISUAL CASE, in: The UFO Encyclopedia, Jerome Clark ed., 1998, pp. 761-790.]


STATUS: Unknown



13.  DATE: July 25, 1957               TIME: 0025 local                 CLASS: R/V ground
                                                                       radar/ground visual

LOCATION:            SOURCE: Thayer, Condon 1970 145

Niagara Falls, N.Y.

                                                       RADAR DURATION: 3 minutes

EVALUATION: Blue Book/Thayer - balloon


PRECIS:  Observers (number unspecified) saw a "circular brilliant white object with pale green smaller lights around its perimeter" travelling slowly at nearly constant altitude. Conditions were "clear with excellent visibility". The object went into a "fast steep climb", disappearing from sight in five to eight minutes. The object was also tracked on a CPS-6B radar for some three minutes in a NE heading.


NOTES:  Thayer points out that: 1) the rate of climb could not have been very great if the object remained in sight for 5 to 8 minutes; and 2) the NE heading of the target agreed with "the prevailing winds in the area". It appears that the Blue Book file on this case may be even less complete than usual.  This fact combined with the above arguments prompted Thayer to concede by default "the official Air Force view that the object was a lighted balloon". But it would appear that no specific balloon release was identified and that the actual winds aloft at the time (as opposed to those prevailing) are unknown. There are several points to be made about this hypothesis.


It is interesting that apparently no attempt was made to interpret the radar target as anomalous propagation, the standard Blue Book default position during this period. The radar and visual sightings are accepted as sightings of one and the same object. This could mean either that it was simply too implausible to invoke AP in this case or that it was unnecessary in this case because radar target and "balloon" were strongly correlated.


A convincing target on a CPS-6B is a priori not especially likely to be due to causes such as AP, interference, internal noise or component failure. The reason is that in addition to the surveillance beam the CPS-6B had integral height-finding by means of two further diverging beams. Measurement of the transit time of a target between these two beams, combined with the range rate fed to the surveillance PPI, yielded the target's approximate altitude. Each of these electronically independent transceivers operated at very different frequencies, and AP effects are frequency-sensitive. If a normal-appearing point target had been tracked in both plan position and altitude by a CPS-6B it would be consistent with Blue Book's decision to opt for a real radar-reflective object - hence the "balloon".


The available information is sparse. Even the exact locations of the radar and visual sites are unknown, for example. Despite the considerable room for conjecture, however, the balloon hypothesis can be criticized if one is allowed to draw some inferences.


It is not specified in the report that the visual observers were service personnel, but it is perhaps likely given that the CPS-6B would have been a USAF Air Defense Command radar and given that the "balloon" was evidently seen at very low level, which implies proximity to the radar site. The reasoning here expands as follows: Weather balloons are not large visual objects. The intercepted arc is undetectable to the naked eye in daylight beyond about 20,000' slant range, and the 1.5 candle lamp of a nocturnal lighted balloon at altitude would be no more than a point source. The object in this case was visually resolved as a disc with a perimeter defined by a number of secondary lights, and if it was a balloon it was inferably no more than a few thousand feet slant range from the observers and at a very low altitude. This implies, in turn, that the "balloon" was close to the radar site where it was detected, because of the way that minimum detectable altitude varies with range.


That Blue Book rather easily dismissed the case as a probable weather balloon, evidently without much attempt to gather confirming data, can be taken to suggest that it took place at or close to a known balloon launch site. This is consistent with the inference in the previous paragraph, and indeed a map of the >100 routine radiosonde launch sites in the US (source, p.146) identifies an airfield a few miles from Niagara, which it is suggested could well be the location of both the radar and the visual observers.


If this chain of inference is correct then several conclusions follow:


1)  the balloon was seen by personnel at a site where radiosonde balloons were being launched 4 times a day, 365 days a year, yet they failed to recognize it as a balloon;

2)  if it was their own balloon and was seen climbing from a low level (at a typical 1000-1200 fpm) it had been released no earlier than a few minutes and was currently being tracked;

3)  records of the release time and weather data would be available, yet after investigation local base intelligence personnel failed to identify the object as their own balloon, forwarding a report of a UFO through channels at a time when there were strong disincentives to do this - including the specific instruction to clear up as many reports as possible at the base level; and

4) Blue Book themselves did not identify the object with any specific balloon launch, despite their suspicion that the object was a balloon, when this should have been easy to do.


Granted there is some supposition here, but it should be noted that the visual description of the object is not strikingly like a balloon. In particular, the ring of green peripheral lights corresponds to no known kind of balloon lighting. The color could be ascribed to an optical contrast effect if the central disc had been described as red or reddish; but this was described as "brilliant white". Scattering of sunlight through the translucent stretched neoprene of a balloon at high altitude can create an unusual glowing appearance near dusk or dawn: but the green color is inappropriate, the time was past midnight, and this "balloon" was at low altitude. Moonlight is a possible source, but a low altitude radiosonde would not be very distended and thus should be essentially opaque; again there is no convincing explanation for either the brilliance of the central disc or the ring of green lights. If a balloon was being tracked whilst illuminated by a searchlight for some reason this simply increases the strangeness of so noteable an experiment being unknown to base intelligence officers. The only likely source seems to be the balloon's own tracking light, but as has been mentioned these 1- or 2-candle lamps are scarcely "brilliant" and would at best very faintly illuminate the undersurface of the balloon (note that pilots in close encounters with balloons have typically mistaken these lamps for small "UFOs" precisely because the fabric of the balloon itself was invisible); there is essentially no likelihood that this lamp would also be bright enough to generate an array of discrete specular reflections disposed around the periphery of the balloon, and no obvious reason why they should appear green if it did.


This last point raises the suggestion that what was seen was a very large research balloon at great altitude, unconventionally illuminated for who knows what special purpose. When stretched by internal gas pressure at high altitude, the orange-like segmentation caused by the seams of such balloons can be very visible, and it is possible to imagine that the peripheral lights were highlights on a reflective material. But it is difficult to square steady balloon drift at a great height either with the eyewitness descriptions of a "fast steep climb" or with the fact that the CPS-6B only had the target on scope for 3 minutes.


The motion of the object, at least during the 3 minutes of radar tracking, was from SW to NE. The prevailing wind at Niagara is generally SW. This is really the only strong point of similarity between the object and a balloon. The report does not contain any estimate of the speed or kinetics of the radar target, but the visual observers estimated that the object's movement was slow and at a level altitude until it went into "a fast steep climb". Qualitatively speaking this does not sound like behavior typical of a balloon.


Thayer questions the implied rate of climb by pointing out that if it remained visible for 5 to 8 minutes then it cannot have climbed very fast, suggesting that this is consistent with a balloon. However, this argument is not entirely valid. It is an example of a theory-dependent argument: A balloon light isn't very bright; if this light wasn't very bright it can't have climbed high and fast, otherwise it would not have been visible for several minutes; it was visible for several minutes, therefore it must have climbed low and slow. Ergo, it was a balloon.


Firstly, it should be said that there are no data on the intrinsic luminosity of "a UFO", and therefore it cannot be said to what altitude such an object might be visible; hence it is not possible to conclude that the rate of climb implied by a duration of 5 to 8 minutes must have been low. Secondly it can on the other hand be argued that this time is far too short for a balloon. A lighted weather balloon climbing at an average 1100 fpm from an initially very low altitude (ex hypothesi) for a mean estimated 6.5 minutes would only have reached an altitude somewhat above 7000' and should have remained visible - in the "clear" sky with "excellent visibility" - as a source of magnitude in excess of +3, that is, brighter than an average star. (A 1-candle source at 1000 meters has a visual magnitude of +0.8, from which it may be calculated that a 1.5-candle source would be visible to over 15,000' as a 5th magnitude light - that is, still more than  twice as bright as a faint star - and could have been seen for about 15 minutes. Indeed, some balloon lamps are 2 candle, so the above values should be taken as minima.)


Conversely, a light which was described as "brilliant" when closest to the observers might be thought brighter than a small lamp of 2 candle or less. At a slant range of only a couple of thousand feet, for example, a 1.5 candle radiosonde lamp would have a brightness of about -1.5, some 5 times fainter than the planet Jupiter at opposition and about 10 times fainter than Venus which is commonly described as "brilliant". Of course these comparisons are only illustrative, since the relative magnitude of a balloon lamp is very sensitive to distance owing to the inverse square relation, and the true distance is not known (without the full radar report). Nevertheless it is fair to say that for a balloon lamp to appear "brilliant" it has to be very close, which means that the start of its visible ascent would be very low, reinforcing the argument that it should have stayed visible from the ground for appreciably longer than 5 to 8 minutes. If the intrinsic luminosity of the source were much brighter, of course, then a visible ascent of this duration implies a proportionately rapid rate of climb to a propor-tionately greater altitude.


These arguments are hardly conclusive, since the start altitude of the ascent cannot be accurately inferred and, more importantly, the "disappearance" of the light may not have been due entirely to its dimming below the level of perceptibility; it may, for example, merely have become indistiguishable from the surrounding stars. The reports of duration could be wrong also. But the match with the behavior of a lighted balloon is hardly conclusive either, and the prior motion of the object has to be taken into account. If it was a balloon then its initial horizontal motion would be best explained by a leaking balloon with a near-neutral buoyancy; but such a balloon could not spontaneously become buoyant again and ascend rapidly out of sight. And anyway, a balloon with less than maximum buoyancy would have a slower rate of climb still less consistent with the mere 5 to 8 minutes during which it was observed visually. It is possible for such a balloon to be caught up by a local updraft, but whether it could remain in such an updraft (in the clear weather of a summer night, let us remember), losing buoyancy all the while, for several minutes until it was borne upwards out of sight is to say the least debatable.


In conclusion, it appears likely that the same object was seen visually by multiple military observers and tracked rather unambiguously on ADC radar for 3 minutes (although there is insufficient information to prove this). The balloon hypothesis is not very strong as it stands. The reported motions of the object can only in part, and inconclusively, be compared to a balloon. The object has not been identified as a specific balloon despite evidence suggesting that it should have been easy for base intelligence officers to do so. Data on the actual winds-aloft conditions at the time were apparently not obtained, so that the only direct correlation invoked in support of a balloon is suppositious. The reported visual appearance of the object, as described by witnesses who might be expected to be familiar with local balloon launches, is not consistent with a balloon. No other conventional object or phenomenon accords with the description of a brilliant disc encircled with green lights, which reportedly displayed considerable angular motion and appears to have been a radar reflector.


In terms of the information available the case is an "unknown". However, in view of the shortcomings of the Blue Book file - in particular the absence of crucial weather and radar date - it is judged reasonable only to carry the case as "insufficient information", with the rider that it would appear to warrant further study.


STATUS: insufficient information



14.  DATE: August 30, 1957                 TIME: night                            CLASS: R/V air radar/air

LOCATION:                                       SOURCES: Thayer (Condon 128)

Chesapeake Bay

Nr. Norfolk, Virginia                           RADAR DURATION: unspecified


EVALUATIONS: Thayer - unknown


PRECIS: A Capital Airlines pilot with 17 years & 3,000,000 miles logged was flying a Viscount at 12,000' approaching Norfolk, Va., with a Northeast Airlines DC-6 "directly above" on the same heading at 20,000. The Viscount pilot saw a "brilliant" object which "flew fast and then abruptly halted 20 mi. in front of us at 60,000 ft. altitude." The Northeast pilot tried to acquire the object on radar: with the antenna at 0 degrees elevation nothing was detected, but with the antenna elevated to 15 degrees he acquired "an excellent blip right where I told him to look for the object." According to the Viscount pilot, the object "dissolved right in front of my eyes, and the crew above lost it from the scope at the same time. They said it just faded away." The entire incident lasted "several minutes".


NOTES: Thayer points out that if the DC-6 radar at 20,000' painted the target at 15 degrees elevation, range 20 miles, this would place the object at a little less than 50,000', not at the 60,000' estimated visually by the Viscount pilot. This might be thought a good match within the limits of observation and second-hand reportage (the DC-6 pilot did not apparently report his radar contact officially), and perhaps does not warrant Thayer's remark that the pilot's visual estimate was "in error". Further, the vertical coverage of the DC-6 radar would be at least several degrees and would paint a target with the antenna boresight aligned to a point somewhat below its real elevation (15 degrees quite possibly being the maximum antenna tilt limit), so it is not excluded that the match between visual- and radar-altitude indications was exact. Thayer's conclusion that the real visual elevation angle from the Viscount was 19 degrees, therefore, appears unwarranted, even if we accept the tacit assumption that radar and visual observations were of the same "object".


   However, following Thayer's reasoning for the sake of argument, his analysis concludes that 19 degrees is too steep an angle for any temperature inversion to produce an optical mirage of a celestial body; and the above qualification of that reasoning increases the possible angle beyond 19 degrees, so further lessening the likelihood of mirage. Thayer also dismisses partial inversion reflection of ground targets at optical or radar wavelengths, concluding that the incident must be considered an "unknown".


    Nevertheless, a question mark remains over the apparent absence of any visual sighting from the DC-6 of the "brilliant" light being watched from the Viscount. The DC-6 had to be "told where to look" in order to pick up the radar target; they did so, but apparently still saw nothing. Without an independent report from the crew of the DC-6 it is difficult to resolve this discrepancy. As it is, one must consider the possibility that the Viscount crew were watching  something in local airspace which they mistook for a brilliant object at altitude, whilst the DC-6 radar indication was coincidental despite the reasonable match in reported position and time of disappearance. Individually, the visual report could be explained as an initial meteor plus (say) a nearby a/c turning its landing lights on and off, whilst the radar contact could have been system noise, interference, or a high-altitude ice-laden cloud which left radar coverage due to the plane's forward movement. The DC-6 crew, meanwhile, would have been following Viscount's directions and looking up, thus either not seeing a lit a/c below their altitude or assuming it was the Viscount (itself invisible directly below).


   The above explanation may be less than probable, particularly given a visual duration of several minutes ("brilliance" of an a/c's forward-facing landing lights would imply a heading significantly away from that of the Viscount, and thus a fairly rapid relative motion), nevertheless it illustrates that the two sightings are insufficiently reported to evaluate with confidence. One possible explanation of the major part of the incident would be a high-altitude research balloon carrying an instrument payload. Such a balloon might reflect the sun brightly even in dark-sky conditions, and might appear suddenly from behind obscuring high clouds. When cut down it would rapidly collapse or shatter ("it dissolved right in front of my eyes") and its radar-reflective payload would fall away under gravity until its chute opened, thus possibly dropping out of the DC-6 radar pattern quite quickly if it were near the lower limit of coverage. However this explanation is quite speculative: a) the time would require to be near dusk or dawn, but the time is not known; b) the a/c heading would have been roughly NS and the object was "in front", thus in the S sky and not ideally placed (i.e., not on the W horizon) to reflect the sun if sky conditions were "night" as reported; c) radar reportedly confirmed the object at less than 60,000', which is low for optimum chance of noctilucence and low for cut-down, which would normally take place at float altitudes above 100,000'; d) there is no explanation for the high-speed initial sighting without assuming a coincidental bright meteor; d) this construction requires a fortuitous distribution of cloud to explain why the illuminated balloon was seen for several minutes from the Viscount, but was at no time visible to the DC-6 crew flying 8000' above.


STATUS: Insufficient information



15.  DATE: November 4, 1957      TIME: 2245 local               CLASS: R/V ground radar/
                                                                                                               multiple ground visual

LOCATION:                                        SOURCES: McDonald (Symp. 115)

Kirtland AFB                                                            Hynek (1978) 76

Albuquerque,                                                             Thayer (Condon 141)

New Mexico

                                                              RADAR DURATION: several minutes

                                                                     (two episodes separated by approx. 20 mins.)


EVALUATIONS: Blue Book/Thayer - aircraft


PRECIS: Two CAA tower controllers observed a white light travelling E at an estimated speed of 150-200 mph, estimated altitude approximately 1500' on low altitude airway Victor 12. When the light reached the E end of Runway 26 it turned and came down SW in a "sharp descent" towards the tower. The object was at this time believed to be an aircraft confused about its landing pattern (conditions were darkness, scattered clouds and a high overcast, with good visibility despite some light rain over the airfield). A LOGAIR C-46 had just called in for landing instructions, and the tower queried the unknown traffic without response. The object then proceeded across the airfield towards the tower at an estimated altitude of a few tens of feet, at which point it was observed with 7x binoculars and appeared as an approximately egg-shaped body, 15'-18' on its major vertical axis, somewhat like "an automobile on end" with no features or control surfaces and a single white light on its base. It approached a B-58 service pad near the NE corner of Area D (a "brilliantly floodlighted" restricted area S of the EW runway), slowed to approximately 50 mph, then stopped completely, estimated range 3000' ENE from tower. It remained stationary for an estimated 20-60 seconds then began moving again at a modest speed on a heading E away from the tower at 200-300'. At this point the object was approximately over the E perimeter, and in case it might be a helicopter in distress one controller gave it a green light from the tower. It veered SE into an abrupt climb at a speed estimated as approximately Mach 1 (45,000' fpm) and disappeared into the high overcast, a manoeuvre which in the opinion of the observers exceeded the performance of any jet.


   At this time the controllers called CAA Radar Approach Control and asked for verification of a fast target to the E. The RAPCON operator confirmed a target on the PPI of the CPN-18 surveillance radar on a 90-degree azimuth approximately over the E perimeter on a heading SE. At an unspecified range the target "reversed in course" taking up a W heading which took it towards the Kirtland low-frequency range station. At this point (a position E of S from the radar site) the target began to orbit for a period of minutes, then moved off on a NW heading "at a high rate of speed" to a position 180 degrees azimuth from radar site (S) range 10 miles, where it was lost.


  20 minutes later the operator "scanned radar to the south" as an Air Force C46 (4718N) was taking off W on the EW runway and making a left (S) turn. He saw a target which he took to be the same unknown over the outer marker approximately 4 miles S of the end of the NS runway. The target approached N at "a high rate of speed" to a position 1 mile S of the EW runway, made an  "abrupt" W turn and fell into trail with the C-46 on a S heading, maintaining an approximate -mile separation for some 14 miles. The target then turned back on a N heading to hover over the outer marker for 1-1 minutes, then "faded" from the scope.


NOTES:  The above precis removes certain inaccuracies from the principal published accounts (Macdonald, quoting partial Blue Book file + witness interviews and site visits; Hynek, quoting partial Blue Book file). Hynek's account misconstrues the timing of events as a simultaneous radar-visual, introducing discrepancies in the attempt to relate radar and visual course descriptions. McDonald's account is clearer in this regard but does not draw on the original radar operator's report, and thus confounds the later radar event with the former, introducing minor azimuth errors and erroneously stating that the target followed the C-46 off-scope. Thayer's account confuses by stating that the object disappeared from view "behind some buildings" when it came down in Area D, whereas McDonald established (from site visit & base records) that there had never been any such buildings in Area D, only chain-link fencing, and (from witness interview) that the object never in fact disappeared from view. The problem appears to originate with the Blue Book summary, which states that the object "disappeared behind a fence", presumably based on witness statements that the object descended behind a [chain-link] fence.


   The Air Force investigation noted that the two tower observers, who had 23 years of aircraft control experience between them, were mature, well-poised, of well above average intelligence, thoroughly consistent and cooperative, unshakeably convinced of the accuracy of what they reported, and were believed to be "completely competent and reliable".


  This is a very interesting case despite the evident fact that radar and visual observations were at no time simultaneous. Visual disappearance and radar acquisition were immediately consecutive and fairly consistent as regards target location and heading. The behavior of both visual and radar targets is convincingly non-random, and in many ways does suggest a piloted vehicle, but the Blue Book evaluation of "possible aircraft" (endorsed by Thayer) is less than satisfactory, doing violence to the visual descriptions as well as to certain aspects of the radar track. A helicopter would be more plausible if it were not for the visually-observed Mach 1+ climb out; presumably it was this factor, and possibly the unquantified "high rate of speed" observed on radar, that forced Blue Book to opt for a fixed-wing aircraft. Similarly, Thayer suggests "a small, powerful private aircraft, flying without flight plan, that became confused and attempted a landing at the wrong airport." However, the object was seen visually to maintain station at very low altitude in Area D for a period approaching 1 minute whilst under observation with binoculars, and the target tracked during the second radar episode exhibited the same behavior at least once, "hovering" for somewhat more than 1 minute. The object was observed visually for nearly six minutes, both with binoculars and the unaided eye, in "good" visibility, and for a time close to the ground in a brilliantly floodlit area at a range of 1000 yards, by two experienced observers who declared firmly that it in no way whatsoever resembled an aircraft.


   The visual description is more like a partially deflated balloon than anything else. A leaky radiosonde with a tracking light, perhaps released from Kirtland itself, might have drifted around the airfield in a gusty breeze (surface winds  were "variable at 10 to 30 knots"). Such a balloon would not be 15'-20' in size since this would be its fully inflated diameter at many thousands of feet, but in conditions of darkness and occasional light rain it might be possible for observers to overestimate its distance, size and speed. However, it has to be said that such experienced control tower operators would be very familiar with balloons in all conditions, and to watch a radiosonde for several minutes with binoculars believing it to be an unfamiliar object travelling between 0 and 700 mph+ would be an unlikely aberration in the circumstances. If the subsequent radar track had been consistent with a radiosonde one might be willing to accept this order of unlikelihood; but although a period of "circling" is not unlikely for a balloon climbing through variable winds, the target's "high rate of speed" and very marked changes of course render the probability negligible, even disregarding the behavior of the very similar target reacquired 20 minutes later.


   This lapse of time is also of relevance to the "confused aircraft" hypothesis: granted that there is no continuity of tracking to certify the identity of these two targets, nevertheless it is valid to observe that the same pilot is unlikely to have still been flying around "confused" after 20 minutes, whereas to assume a second, unrelated "UFO" with very similar characteristics adds another order of unlikeliness. It does seem reasonable to treat the two radar contacts as related.


   In general, the ordered and continuous movements of the radar target(s) are unlike those typical of anomalous propagation, and although no refractivity profile is available the gross conditions (winds gusty and variable, scattered clouds with a high overcast and light rain in November) are not very conducive to atmospheric stratification. Multiple-trip returns from an airborne target beyond the unambiguous range seem improbable given the target's movement over a 90-degree sector, at least in part at "high" speed, punctuated by a period of "orbiting", although it is noteworthy that the specified high-speed portion of track from a position E of S on a heading NW (the geometry is very rough) could be construed as approximately radial, which is the heading on which a multiple-trip target's true speed would be displayed (lateral movements being displayed at spuriously slow speed). This positive match is however not a very strong indication given the general context, and would usually require super-refractive conditions for which there is no evidence; also the orbital behavior does not suggest the kind of distorted courses and speeds typically displayed by multiple-trip (although such behavior is conceivable); and furthermore, the second radar episode combines stationarity with "high" speeds unambiguously, which is difficult to equate with any mobile target displayed by multiple-trip returns. No side lobe leakage effects, internal electronic artefacts, RFI, birds, insects or CAT are relevant to such a target. "Interceptions" of a/c by targets in the manner of the second radar episode are often qualitatively similar to "ghost" reflections caused by returns from a secondary ground target via the a/c as primary reflector, but it is readily apparent that the required reflection geometry (with the ghost always on the same azimuth as the a/c and at greater range) does not apply in this case.


   In summary the a priori likelihood that radar and visual observations related to the same real target does not seem to be reduced by analysis. This conclusion is reinforced by the ordered nature of the target behavior, both radar and visual, in relation to a number of significant ground installations around the airfield: The (visual) object turned at the end of the EW runway as though on an approach; it came to a halt over a service pad in restricted Area D; it made its rapid ascent once it reached the E base perimeter, coincident with the green  light from the tower. The radar target(s) then proceeded from the base perimeter to the low-frequency range station, where it orbited; it reappeared over the S outer marker; it then moved into trail with the C-46; and finally went directly to the (S?) outer marker where it disappeared (possibly by descending below the radar). These are persuasive indications of rational, intelligent behavior, which a priori favour a piloted aircraft or helicopter. The kinetics and appearance of the object, however, are not individually or collectively consistent with any type of conventional aircraft or helicopter. The possibility of some sort of experimental VTOL aircraft or early RPV cannot be ignored, although this is presumably unlikely around a busy facility adjacent to Albuquerque Airport - without warning, yet open to observation by CAA and other non-military witnesses for twenty minutes or more - given the availability of secure test facilities such as White Sands 150 miles to the S.


STATUS: Unknown



16.  DATE: November 5, 1957          TIME: 0510 local                 CLASS: R/V  shipboard
                                                                                                                        radar/deck visual

LOCATION:                                    SOURCES: Thayer, Condon 165

Gulf of Mexico                                           Mebane (app. Michel FSSLM '58 242)

                                                                              Lorenzen SEIOS 1966 101

                                                           RADAR DURATION: 27 mins. (intermittent)

EVALUATION: Blue Book - Venus/aircraft

                            Thayer - aircraft/AP/meteor


PRECIS: At 0510 the U.S. Coast Guard Cutter Sebago was in the Gulf of Mexico some 200 miles S of the Mississippi delta at 25 degrees 47' N, 89 degrees 24' W on a heading of 23 degrees true, when a radar target was acquired on a 290 degree true azimuth at a range of 14 miles, heading S. The target turned in towards the ship, closing to 2 miles, then returned N along the ship's port side. The target was lost at 0514, and average speed was calculated as 250 mph.


   Two minutes later at 0516 a second target was picked up, bearing 188 degrees, range 22 miles, and was plotted to a position 190 degrees, 55 miles, where it was lost. Departure speed was measured at 650 mph.


   At 0520 a stationary target was displayed at 350 degrees, 7 miles range. At 0521 a visual object "like a brilliant planet" was observed from the deck for about 5 seconds travelling S-N at 31 degrees elevation between 270 & 310 degrees azimuth. At about the same time the radar target moved slowly NE, and finally accelerated rapidly, moving off the scope at 0537, 15 degrees, 175 miles range.


NOTES: The most reliable published source is Thayer, drawing directly on the Blue Book case file, and the above precis reflects this. The 1958 account by Mebane appears to contain some errors of timing. Certain circumstantial details in Mebane are of interest, however, drawn from a press report and a radio interview broadcast by WBZ, Boston, on the following day.


   The initial explanations offered for the Sebago report in USAF press releases on November 15 & 17 were the planet Venus, two unspecified aircraft - a piston-engine light plane and a jet - plus some possible "false" targets. According to Thayer, the first radar target "behaved generally like an aircraft", and he inclines to accept the Air Force view that it probably was an aircraft, possibly from Eglin AFB to the N. No specific flight could be identified as the culprit, however. The second target, which Blue Book apparently concluded was probably a jet, is attributed by Thayer to anomalous propagation. Thayer also explains the third target as AP, and the concurrent visual as "undoubtedly a meteor".


   Whilst these coincidences may on the face of it seem improbable, and the whole melange a little desperate, Thayer points out that radio refractivity data for Key West, Florida (the nearest applicable soundings) show the possibility of unusual propagation conditions, with marked temperature/humidity stratification conducive to partial reflection echoes. Further, he argues that since the moving visual object appears to have been seen at a time when radar showed a  stationary target, and apparently at a different azimuth, the two events cannot be related, and the brevity of the visual sighting is suggestive of a meteor. It is only prudent to point to some reservations about this scenario, however.


   An alternative and quite plausible explanation of the visual sighting (in fact proposed by Tulane University astronomer Dr. J. F. Thompson in an interview for the New Orleans Times-Picayune as early as November 6 1957) is Sputnick 2. The second Soviet satellite had been launched on November 3 into an inclined 65-degree elliptical orbit with a perigee of 140 miles, and would have been visible west of the Sebago's position travelling roughly NNW at about that time.


   Thayer relates from the report that "the third radar target remained stationary for about 1 min." before moving off to the NE. It is implied that this minute elapsed after the visual object had been observed at 0521, and thus the target movement would have begun not earlier than 0522. But the statement is ambiguous. The stationary target was acquired at 0520; if it then "remained stationary for about 1 minute" its movement would be consistent both in time and approximate heading with the moving object observed visually. This is a moot point, but it might also be noted that times are only given to the minute, and the difference between approximately 0521 and approximately 0522 could only be seconds. Therefore, given that the visual observation was made by members of the crew other than the radar operator - four hands who had gone up to the bridge to look for the object; given the possibility of small errors in independent timing; given that times are only cited to the minute; given that the precision of a phrase like "about one minute" is a debatable estimate of elapsed time; and given that the material discrepancy is only about a minute - then to conclude that the visual and radar movements were definitely inconsistent as to time may be to expect too much of the information available.


   The visually observed heading S-N at 31 degrees above the horizon might, as we have said, be consistent with the radar heading SW-NE. However, the visual report has the object moving from 270 degrees to 310 degrees, whereas radar reports the target moving from 350 degrees to 015 degrees. How accurate are these values, and how significant is the discrepancy?


   The radar bearings are given "true" - that is, in relation to true longitudinal north. These true values can be read off directly from the bearing ring if the heading marker - a bright scope trace - is aligned to the ship's true course (so-called "north-up" presentation). With the heading marker aligned to 0 degrees ("heading-up"), indicated bearings will be relative to the ship and would have to be corrected by the operator. Furthermore it is essential that the heading marker is continually stabilised to the true course if true readings are to remain true. This can either be done manually by using a picture-rotate control, or automatically by a linkage with the ship's gyro compass; but even if automatically stabilised it is advisable to check picture orientation from time to time, since the compass will only correct it relative to its initial setting. With the heading marker switched off an operator might conceivably become confused, momentarily, as to whether displayed bearings were true or relative. And on a manually aligned scope an excited operator might neglect to correct bearings for yaw. Therefore there are possible sources of error. However, given that this was a Coast Guard vessel and that the operator would presumably be well-trained, there is no reason not to assume that the marker was correctly set on an automatically stabilised display. The bearings cited are probably accurate.


    But the possibility exists that the visual bearings are translated from positions off the bow, which is quite common practice at sea. The figure of 270 degrees might be taken as supporting this guess, since this would correspond to exactly 90 degrees to port and is the kind of "cardinal point" approximation that might well be given by a visual observer recalling a fleeting observation off the port beam and offering a rough guess as to the start-point of a trajectory which was initially seen out of the corner of his eye. If this were the case, then the quoted values would have to be increased by the 23-degree heading of the ship to give true azimuths, yielding bearings of 293 degrees and 333 degrees true. Some allowance might also be made here for what is, ex hypothesi, an approximation of the bearing angles of a transient light seen in the pre-dawn dark, and it is well known that even experienced observers can be quite inaccurate in estimating visual angles, even in relaxed conditions. Perhaps the most that ought to be said is that a light was noticed heading approximately N somewhere off the port (W) bow, and it is far from certain that this is inconsistent with the initial position of the radar target some 33 degrees off the port bow.


   There is a fairly important inconsistency in reported speeds, however. According to the radar report, the target moved off relatively slowly from a range of 7 miles, only accelerating rapidly towards the end of its track some minutes later. But the visual observers estimated that the light travelled 40 degrees in five seconds: at a constant range of 7 miles, an angular rate of 8 degrees a second translates to a speed of 3600 mph. And this figure does not allow for the significant radial vector of the target, which - if light and target were one and the same - would drive the true speed very much higher still. We will show later that the mean speed of the radar target was about 650 mph, which, given that it accelerated from zero to its maximum speed shortly before going off-scope, demands that its initial "slow" speed was significantly lower than this figure. Thus, radar-visual consistency would demand that the visual witnesses made at least a factor ten error in their estimate of angular rate.


   As regards the hypothesis of partial radar reflection from inversion strata, which Thayer suggests to explain the second and third targets, it should be noted that the refractivity data quoted were indeed, as he concedes, "taken at some distance from the ship's position" - in fact, some 400 miles from the ship's position, and even given that subtropical atmospheric patterns of this sort "tend to extend in rather homogeneous form over large horizontal distances", one has to admit that there is a good deal of speculation here. Furthermore, the refractivity profile on which Thayer concentrates as being especially likely to generate strong partial reflections was taken at 1800 CST on the following evening; the stratification of the more relevant 0600 CST Key West profile, whilst still significant, is not nearly so marked.


   Thayer adduces support for the AP hypothesis from the fact that the two latter targets appeared "suddenly" on the radar, well inside its maximum range (at 22 miles and 7 miles respectively), suggesting thereby that these were probably phantom echoes. However, all three targets appeared well within range, including the first (at 14 miles) which Thayer nevertheless believes was probably an aircraft. This behavior - which can be explained in terms of targets entering the top edge (this being a marine radar) of the radiation pattern - cannot therefore be held to be uniquely diagnostic of AP. His assertion that the targets "were, with the possible exception of the first one, erratic and unpredictable in their movements" finds no clear basis in the report; the latter two targets  moved on roughly constant headings, the third being tracked NNE to the maximum range of the display (175 miles), whereas the first - the "aircraft" - meandered south, then east, and then roughly north. The latter two targets displayed high speeds during departure, and one appeared to accelerate from a standing start, but it is mischievous to describe such movements as "erratic and unpredictable", and the first target was at least no less "erratic".


   The behavior of the two later targets is interesting in the context of partial reflection echoes, which tend to move at twice the wind-speed at the layer, generally with the wind or at an acute (<90 degree) angle to the wind. At least, the direction of movement will have some component vector related to the heading of the wind. The headings of the radar targets can be reconstructed from the range and bearing data given: In the case of the second target, its heading was 192 degrees, or about SSW; the heading of the third target detected a couple of minutes later was diametrically opposite, 17 degrees or about NNE. Further, the measured speed of the second target was 650 mph, which would equate to winds of over 300 mph, and whilst this might be dismissed as a misreading of sporadic echoes on a relatively fleeting track the third target was painted in movement for some 15 or 16 minutes, which yields an average speed over the 170 mile track of, coincidentally, about 650 mph. Finally, the third target maintained station for one or two minutes before moving off and accelerating, which is not easy to explain as an effect of strong winds driving waves on the surface of an inversion layer.


   To summarise so far, some elements of the AP explanation are questionable, and it is not proven that the visual sighting was unrelated to the approximately concurrent radar target although they are markedly inconsistent in terms of estimated speeds.


   The visual sighting could have been a meteor or Sputnick 2, and the first radar track apparently did not display any characteristics which could not equate with an aircraft, even though no responsible aircraft could be identified. The radar targets could possibly be explained as noise tracks, although more information about scope presentation and movement would be desirable and the duration of track 3 is possibly excessive. Track 2 could possibly have been a jet flying at high altitude, entering and leaving the top edge of the radiation pattern (a low altitude jet would probably be displayed for longer by a radar designed principally to detect shipping and coastal features). Track 3, with a stationary episode, was almost certainly not a jet as this would require a steep climb or dive on a radial heading which preserved constant slant range and azimuth for as long as 2 minutes, a highly improbable circumstance. (Multiple-trip echoes from a jet beyond the unambiguous range could give a spuriously high ratio of displayed minimum/maximum speeds if, for example, it turned from a tangential onto a radial heading. Any non-radial motion would be slower than true, since the angular rate is preserved but at spuriously short displayed range. However, given an angular rate which was imperceptible on the scope for one or two minutes at typical mid-'fifties US marine radar scan-rates of 15-20 rpm, yielding at least 15 consecutive paints, a jet-speed target would have to be at such an immense range that one doubts if it could possibly return a detectable signal on such a navigation radar, of low power typically on the order of 30-40 kW or less. If one supposes a target with a proportionately immense radar cross section - say a flight of several large, well-aspected military transports or bombers, integrated below the resolution of the display - then an inconsistency emerges with the displayed speed of 650 mph. The actual true speed of such a  multiple-trip target with a non-radial vector would be significantly in excess of this figure.)


   The speed of track 3 rules out a helicopter, and no VTOL jets were flying in 1957. Birds, insects, meteor-wake ionisation, CAT, balloons or other wind borne objects are inappropriate. Multiple-trip echoes of Sputnick 2 at a true slant range of (at least) several hundred miles are highly unlikely on a low-power marine radar, and anyway could not explain the extended stationarity and subsequent extreme acceleration of the target. Multiple reflection "ghosts" offer no useful explanation of an echo which was stationary for up to 2 minutes and then accelerated through Mach 1 with a 25-degree change in azimuth: the possible reflection geometries of "ghosts" are complex, but suffice it to say that this behavior requires, amongst other conditions, at least one moving aerial reflector (i.e., aircraft) in the radiation pattern, which as the primary reflector would present a stronger echo than the "UFO" blip itself and would appear to be "shadowing" the UFO at slower speed closer to the ship. No such target was reported. Whatever secondary reflector we might hypothesise (another aircraft, ship etc.), it is highly improbable that this kind of reflection geometry could be maintained for upwards of 15 minutes. And finally, the stationary episode cannot be explained by the same "ghost" echo, requiring either a quite different primary reflector or another explanation altogether.


   As a postscript, it is worth adding that another incident involving the ship SS Hampton Roads took place that evening not far (about 180 miles) from the location of the Sebago incident. The ship was at 27 degrees 50' N, 91 degrees 12' W when a "round glowing object" was sighted at apparently high altitude at 1740 LST. It was observed for 10 minutes, and was lost to sight as dusk drew on at 1750. This object was explained by Blue Book as a probable balloon drifting with the upper winds, which is certainly plausible. In the absence of more detail, it is also possible that this was another sighting of Sputnick 2, disappearing as it moved into the earth's shadow.


   In conclusion, although a conventional explanation of the Sebago sightings might require a series of coincidences, and although some elements of that explanation remain open to question, nevertheless the visual sighting in particular is of low strangeness, and its correlation with the radar track is somewhat doubtful. Considered alone the radar data available, whilst interesting, cannot be said to strongly support an unconventional interpretation.


STATUS: Insufficient information



17.  DATE: May 5, 1965              TIME: 0110 local                        CLASS: R/V shipboard
                                                                                                                      radar/ deck visual

LOCATION:                                SOURCES: Hynek (1972) 81

Philippine Sea

                                                     RADAR DURATION: 6 minutes


EVALUATIONS: Blue Book - "aircraft" & "insufficient data"


PRECIS: The official report states:


At 060910, in position 20 degrees 22 minutes north, 135 degrees 50 minutes east, course 265, speed 15, leading signalman reported what he believed to be an aircraft, bearing 000, position angle 21. When viewed through binoculars three objects were sighted in close proximity to each other; one object was first magnitude; the other two, second magnitude. Objects were travelling at extremely high speed, moving toward ship at an undetermined altitude. At 0914, 4 moving targets were detected on the SPS-6C air search radar and held up to 6 minutes. When over the ship, the objects spread to circular formation directly overhead  and  remained  there  for  approximately  3  minutes. This maneuver  was observed both visually and by radar. The bright object  which  hovered  over  the  starboard  quarter  made  a  larger presentation  on  the  radarscope.  The objects  made  several  course changes during the sighting, confirmed visually and by radar, and were tracked at speeds in excess of 3,000 (three thousand) knots. Challenges were made by IFF but were not answered. After the three-minute hovering maneuver, the objects moved in a southeasterly direction at an extremely high rate of speed. Above evolutions observed by CO, all bridge personnel, and numerous hands topside.


The report carried an addendum:


During the period 5-7  May, between the hours 1800 and 2000, several  other  objects  were  sighted. These objects  all  had  the characteristics of a satellite, including speed and [presumably visual] presentation. These are reported to indicate a marked difference in speed and  maneuverability between these assured satellites and the objects described above.


NOTES: This report, as usual in Blue Book reports, implies a very great deal of missing  information.  In  terms  of  the  information  available,  however,  the unequivocal  statement  that  very  particular  movements  were  several  times confirmed visually and on radar makes it of interest. There are minor questions as to the date, which Hynek lists as May 6 in his appended catalogue, and the duration, which he lists in the same appendix as 8 minutes, whereas the report states that the radar targets were held for 6 minutes beginning 4 minutes after visual acquisition, making 10 minutes overall.


The ship would have been about 150 miles S of the Tropic of Cancer steaming at 15 knots on a heading a little S of W towards the northern tip of the Philippine island of Luzon, 900 miles away across open ocean. The first visual sighting  was  dead ahead at an elevation of  21  degrees. The distance to land rules out an optical mirage of shore lights, and the elevation exceeds the critical grazing angle by a factor of forty, ruling out a  mirage of shipboard lights. Further,  the  approach  at  "extremely  high  speed"  towards  the  ship  implies (although it doesn't guarantee) that this initial elevation increased during the four minutes. Presumably the light seen was white (as no colour is mentioned, and the comparison made with the visual appearance of satellites mentions no dramatic  distinction  due  to  colour)  and  presumably  did  not  notably  flash, scintillate or wander erratically even as viewed through binoculars. It resembled a steady aircraft light and was initially so identified. There seems no reason to suspect any atmospheric-optical component to the initial visual sighting.


Through  binoculars the  light resolved  into  3  sources, one of the 1st magnitude, two of the 2nd, which, visually integrated, would imply a naked-eye object of no great brilliance but brighter than most of the stars. No estimate of visual  magnitudes  is offered  for the  objects  as  later seen  "directly  over the ship",  but  it  is  implied  that  the  overall  "presentation"  of  the  lights  was dissimilar  to,  and  therefore  presumably  brighter  than,  that  of  satellites. Nevertheless,  they  do  not  at  any  time  appear  to  have  been  more  than moderately bright point sources without noticeable detail or extension.


How the 3 objects first seen visually relate to the 4 objects subsequently seen visually and tracked on radar is not clear. The bearing of the first radar acquisition is not stated, but the 4 targets reduced range from 22 miles to "over the ship", and it is at least implied that this approach bore a natural relation to the visual approach of the 3 lights first seen 4 minutes earlier. The 4 radar targets "spread  to circular formation directly overhead", implying  a compact initial configuration not inconsistent with the visual observation, and one of the targets made a larger scope presentation than the rest consistent with visual sightings made previously and concurrently.


The SPS-6C is described as an "air search radar" and was probably a moderately long range S-band instrument used for aircraft detection, wavelength in the range 6-20cm, with the normal toroidal scan volume (possibly a sea-going cousin  of  the  CPS-6  multiple-beam  search  radar).  Such  a  radar would  have sensitive clutter  rejection characteristics  to contend  with sea clutter and the motion of the ship, and frequency agility to combat jamming. It was not a tactical targeting radar, and the report does not mention any other radar being used.  This  being  the  case,  the  report  of  targets  which  "spread  to  circular formation directly overhead" may be in need of some interpretation due to the zenithal radar shadow. One of the 4 targets was "off the starboard quarter", and the clear implication is that the center of the circular formation was directly over the ship with the targets disposed around it at elevations significantly less than 90 degrees. No altitude data are quoted, but it might be inferred from this geometry that if the targets were real radar-reflective objects then they were not at extreme altitude, but in relatively local airspace as is also suggested by their initial acquisition at a slant range of only 22 miles. Visually and on radar, it would seem  that  the target  manoeuvres bore  a  relation to the presence of the ship consistent with this assumption.


The 3 minutes of stationarity rules out fixed wing aircraft, but might be consistent with  reconnaissance  helicopters  from  another  vessel  (presumably "hostile" given the absence of IFF response). However there are objections to this hypothesis: 1) the targets were observed visually by all bridge personnel and "numerous hands topside" whilst disposed around the ship, and with a quiet deck in the middle of the night 4 helicopters hovering in the vicinity would possibly be heard given that at any moment at least one would be upwind; 2) the initial visual  sighting  noted the  "extremely  high  speed"  of  approach,  independent  of subsequent radar tracking, a phrase employed again to describe the objects' radar-visual departure; 3) the radar targets "were tracked at speeds in excess of 3,000  (three thousand)  knots" - about 3450  mph; 4)  given that the period of stationarity occupied 3 minutes of a total 6  minutes radar duration, then even neglecting departure time entirely we are left with a window of 3 minutes for the  targets  to  close  from  an  initial range  of  22  miles,  which  leads to  an absolute minimum target speed during approach of 440 mph relative to the ship (425 mph true), not consistent with the performance of helicopters.


Birds, insects, balloons or other wind borne objects are clearly not appropriate to this  case. The  duration of several minutes is alone sufficient to rule out meteor-wake ionisation. Multiple-trip returns from an artificial satellite could not account for 3 minutes of stationarity or the  manoeuvring of 4  distinct targets,  nor  could  multiple-trip  returns from  any single  reflector account for simultaneous targets at opposite scope azimuths. Distant ships might be displayed at  spuriously  close  ranges  due  to  super-refractive  conditions,  and  the  circular disposition of the targets might result from multiple-trip returns from four such ships detected via an isotropic elevated duct; but the approach and departure of the 4 targets at high speed on narrow azimuths separated by about 135 degrees conflicts with this hypothesis.


The targets apparently approached head on from the W and departed SE, two essentially  radial  headings  which  taken  in  isolation  might suggest  an  internal noise source or RFI, possibly radar pulses from other ships or even (initially) a land-based radar site near Aparri in the Philippines detected due to anomalous propagation. A distant search radar with a pulse length and PRF similar to the SPS-6C but a scan rate slightly out of phase with that of the receiver might be detected as a target reducing range with each scan; a distinct radar source on a ship  at sea to the  SE  might similarly generate  a receding target (air radar operates at very different frequencies and pulse rates). However the scenario is at best  fanciful,  requiring  a  great  deal  of  coincidence  including  radars  with almost identical scan  rates  rotating relative  to  one  another such that the orientations of the receiving and (two) sending antennae coincide near peak gain, and more importantly it does not explain 4 distinct targets arriving, spreading over the ship, and then departing.


A more complex hypothesis would be short-pulse signals arriving with a much longer PRF than the receiver and displaying, not as an integrated target arc but as a number of smaller spots distributed on non-adjacent trace radii. If the input PRF were close to a whole multiple of that of the receiver, then these small "point echoes" could appear at similar ranges forming a group of "targets". If the "scan rate" of the source were, as in the previous scenario, slightly out of phase with that of the SPS-6, then this group could approach scope centre. However, due to the convergence of trace radii such spot arrays will converge to an integrated arc as they approach scope center, not diverge to "spread over the ship", so that a superadded explanation is required.


It  is  qualitatively  speaking  possible  that  if  the  "scan  rates"  of  the  first source and receiver came into phase then the integrated blip could slow and stop, and if at this time the received signal strength were fortuitously enhanced (say, by worsening AP conditions)  the same signal might be spuriously displayed at widely  separate azimuths  due to side lobe-gain as the antenna rotated, the result  being  a  distributed  set  of  apparently  different  targets  at  the  same displayed range with one (corresponding to the peak gain of the antenna) giving a much brighter presentation, as reported. Such an effect, however, would seem to  require  yet  a  third  source  of  RFI  pulses,  since  the  bright  target corresponding,  ex  hypothesi  to  the  peak  summed  gain)  was  displayed  to starboard (N) and thus on an azimuth 90 degrees from the initial signal; also, the  same  constant  source  could  not  generate  rapidly  moving  blips  and, consecutively, stationary blips for as long as 3 minutes; this mechanism does not explain the subsequent movement of the blips away into the opposite sector; furthermore the required signal characteristics (pulse length, wavelength and scan rate all comparable to the SPS-6, but PRF several times that of the SPS-6) do not  correspond  to  any  likely  radar system.  And  finally, the  small spots of excitation produced on the tube in this fashion would (during "approach" and

"departure") in no way resemble the presentation of real targets.


Sporadic  noise sources  seem  highly improbable: very  great variations in measured  speed  from  hundreds  to  thousands  of  knots  could  result  from intermittent noise signals jumping discontinuously between different trace radii on successive scans, but in the absence of detailed scope photos or diagrams one can only say that the likely random behavior of such blips conflicts with the ordered sequence of events reported. Cyclic noise sources local to, or internal to, the transmitter or receiver circuitry are a possible source of ordered blips, but several of the objections raised against remote RFI sources also apply here. In general, any such electronic or propagation artefact must be seen in the context of  specifically  reported  visual  corroboration  of  target  movements  during  the whole incident, and it should be noted that the radar report of targets broadly "over the ship" does not imply the low elevation angles required for anomalous propagation of surface returns or signals from distant radars.


Partial reflection from wind-driven waves on an inversion layer could account for  target  clusters  at  moderate speeds,  but here  too there  are problems:  1) target heading changed by about 50 degrees; 2) the reported maximum speed, as well as the  minimum speed derived from  time and distance data quoted, are impossibly excessive for the 2 x windspeed behavior of such echoes; 3) the 3-minute period of stationarity cannot be explained; 4) such echoes reduce in intensity as the 6th power of the cosecant of the elevation angle, leading to signal strengths proportional to range, and would not be displayed approaching to high elevations in proximity to ("over") the ship.


In summary, it might be possible to conceive a number of highly speculative atmospheric structures and noise/interference effects which, combined with an initial sighting  of  aircraft,  led  to  a  coincidental  sequence  of  radar  and  visual misinterpretations of false blips, stars and meteors by an overexcited crew. But the probability is far too low to constitute a solution. Given the clear statement of  radar-visual concurrence,  and observations by the  Commanding Officer,  all bridge  personnel  and  numerous  hands,  the  very  great  strain  required  to deconstruct  the  coherent  sequence  of  events  reported  into  a  conventional interpretation  seems  unwarranted  and  uneconomical.  There  are  persuasive indications of ordered behavior on the part of self-luminous, radar-reflective objects  which  appear  to  have  had  some  rational  intent  with  regard  to  the presence  of  the  ship,  which  objects  exhibited  speed  and  manoeuvrability inconsistent with the performance of any vehicle known to have been flying in 1965.


STATUS: Unknown





18.  DATE: May 4, 1966        TIME: 0430 local (0340 -Thayer)      CLASS: R/V ground/air
                                                                                                             radar/multiple air visual

LOCATION:                          SOURCES: Hynek (1978) 73

Nr. Charleston                                              Thayer (Condon 163)

W. Va.

                                               RADAR DURATION: 5 minutes


EVALUATIONS: Blue Book - a/c landing lights


PRECIS: At 0340 (or 0430 - Hynek) a Braniff Airlines Flight 42 707 pilot heading E on jet airway 6 at 33,000' saw a bright descending light off to his left which was also painted by the Boeing's airborne radar. He called Charleston ARTC center and asked if radar showed any traffic for his flight. The Charleston high altitude sector controller was distracted by a 'phone call and hadn't seen the appearance of the target, which he now noticed, 11 o'clock from Braniff, range 5 miles. It was a "raw" target (no transponder, which would give on-screen data on flight ID and altitude), and the controller advised Branniff that it must be an aircraft in the low sector below 24,000' as the only other traffic under his control was an American Airlines flight 20 miles behind him. Braniff replied that the object was definitely above him and now descending through his altitude. The controller suggested that it might be a military research aircraft of some sort and asked Braniff for a visual. Braniff replied that it was not an aircraft but was "giving off brilliant flaming light consisting of alternating white, green and red colours". At this time ground radar showed the target closing range to within 3 miles at 10 o'clock from Braniff; Braniff then advised that it was now turning away from him, and the controller saw the radar target execute a smallradius 180-degree turn and reverse its track NW away from Braniff at approx. 1000 mph. Braniff confirmed this and reported that the object was 20 degrees above the horizon and still descending (Braniff's airborne radar indications at this time are not known).


   A sighting of what may have been the same object was made by the pilot of the American Airlines flight 20 miles behind (W of) Braniff: a bright light at 9 or 10 o'clock observed for 3-4 mins. According to the controller, American had been monitoring his communications with Braniff and called the latter, asking if he had his landing lights on. When the controller asked him to amplify, American "politely clammed up". American submitted no report and later disclaimed seeing anything other than what looked like an aircraft with its landing lights on.


NOTES: The likelihood of a real radar-reflective target is in this case quite strong, since correlating returns were reportedly displayed by ground and airborne radars concurrent with matching visuals from (at least) one aircrew. The Blue Book explanation that the object was an aircraft is based on this fact, together with the American Airlines pilot's opinion and the comment that the object displayed no performance beyond the capabilities of an aircraft of the period. No specific identification was offered of the aircraft involved.


   According to Thayer's summary of the Blue Book file, the object was first reported by Braniff at a time of 0340 LST, it was picked up at his 8:30 or 9:00 position, the speed of the ground radar target was 750-800 mph with "no unusual maneuvers", and it disappeared off-scope to the SW after making a "sweeping turn". According to the ARTC controller's account (quoted verbatim in Hynek), the incident began at 0430, the target appeared at 11 o'clock from Braniff moving to 10 o'clock, the speed of the target was approximately 1000 mph, and it left to the NE after making "a complete 180-degree turn in the space of five miles, which no aircraft I have ever followed on radar could possibly do." The controller had 13 years experience with USAF and FAA air traffic control, observing all types of civilian and military aircraft including SR-71's. His account is extremely circumstantial as to Braniff's flight number, VHF frequency, altitude, air lane number and heading, and augmented by a diagram (unpublished) showing the geographic locations of the UFO and the aircraft under his control.


   There seems no good reason to question the controller's statement that Braniff was "eastbound on jet airway 6", which means that a target closing from 9 or 10 o'clock (N or NW) and retreating on a similar course after a turn, however "sweeping", could not possibly be on a heading off-scope to the SW. Either Thayer's summary, or the Blue Book file, or both, are here inconsistent, whereas the controller's first hand account is not. According to that account, the combined speed and manoeuvrability of the target were outside of his experience, also contradicting the Blue Book file which appears to base its assessment of performance (the origin of the 750-800 mph figure is uncertain) on a statement obtained from the reluctant American Airlines witness: " . . . to me it only appeared to be an airplane at some distance, say six or eight miles, who turned on his landing lights . . . . I thought nothing further of it." This also is inconsistent, inasmuch as the object was well in front of Braniff and thus significantly in excess of 20 miles from American, so that American's estimate of landing light brilliance and distance would be out by a factor of 3 or 4. The same pilot speculated: "I presume it was the air force refuelling." Air-refuelling tankers are indeed always brightly lit, but no such operation would normally be in progress close to a commercial airlane, still less on a descending course through it. An Air Force refuelling operation would, presumably, not be difficult for the Air Force to trace; yet no such operation was discovered by Blue Book despite a witness suggesting it. A possible explanation might be a cover-up of a military flight conducted in error; but the radar target could not possibly relate to a refuelling tanker on the basis of speed alone. A military fighter could account for the speed, and for the rapid departure when the pilot realised he was straying close to commercial traffic, but presumably not for the tight 180 degree turn.


   The visual from Braniff of a brilliant light with multicoloured scintillation is more akin to a bright celestial body seen through a sharp inversion layer than anything else, but not on a descending course through his altitude. (Note: Braniff reports the object descending through his altitude, then somewhat later reports it still in a "descending configuration" at 20 degrees above the horizon. This could be interpreted as an inconsistency, inasmuch as 20 degrees seems a rather high elevation for an object to be seen at a depression angle even from 33,000', and this might imply that the object was less mobile in elevation than suggested. However observers almost always grossly overestimate elevation angles, and there tends to be a visual "quantum" of 10 degrees.) A fireball meteor could fit the "flaming" appearance and gross trajectory, flaring and dying to give the illusion  of an object which approached Braniff and then receded; but no trail was reported, and a fireball which was in sight for five minutes would be a very remarkable phenomenon in itself, probably spawning a great many reports, in addition to which the ATC radar track, mimicking the illusory visual approach of the meteor, would become a highly improbable coincidence.


   On ground radar a "ghost" echo from a ground target with Braniff as the primary reflector could simulate an "intercepting" target of this nature: it would appear beyond Braniff and always on the same azimuth, closing as Braniff approached the ground reflector and then receeding in a manner qualitatively similar to that described, although the exact geometry would have to be established. However, Braniff was flying at 33,000' so that such a "ghost" could not be displayed closer than 6.25 miles to the a/c. The unknown target approached to 3 miles. A "ghost" produced by secondary reflection from an airborne target, for example an aircraft passing above or below Braniff, could mimic this behavior, and if we assume that the secondary a/c reflector was itself outside the ATC radiation pattern then it would not itself be tracked on the ground - only its ghost would be displayed. The air radar contact and the visual sighting could have been this a/c, since without the ATC radar track we no longer have to suppose extraordinary performance - merely a fast jet with an unusual lighting pattern, possibly viewed through an inversion at Braniff's altitude. The ground-displayed speed of 1000 mph would be the relative speed of the two reflecting aircraft, not implausible for a military jet flying by a 707 on a near-reciprocal heading.


   However, the hypothetical a/c would be flying as close to Braniff as its displayed ghost (approx. 15,000' of range or altitude) and thus could hardly be outside the overall ATC radiation pattern (the a/c could hardly have remained in a null zone between radar lobes for several minutes); no other aircraft were currently under ATC control except American, 20 miles away; and 5 minutes is a very long time indeed for such sensitive reflection geometry to be maintained between aircraft separating at better than Mach 1.3.


   Further, this hypothesis does not explain the correlation of visual and radar kinetics, and for an inversion layer to explain the abnormal colour scintillations of the light it would have to be viewed at a rather narrow range of relative elevation angles on the order of 1.0 degree, which is inconsistent with a source which was seen descending at speed for several minutes. Other more complex and less homogeneous atmospheric structures might be hypothesised, but the exercise would be highly speculative and unconvincing.


   A similar radar track might be produced on the ATC scope by multiple-trip returns from meteor wake ionisation, although typical ATC wavelengths of 10-50 cm are far from optimum and signal strengths would be low; but the duration is far too long, and Braniff's shorter-wave airborne radar would not have anything like the power output (around 40 kW, or some 5% of typical ATCR output) required for such returns. In general no radar propagation or electronic anomaly can easily explain concurrent, corresponding returns on two very different and physically remote instruments, and the visual observations effectively reduce the probability of anomalous propagation to near-zero.


   In conclusion, the target appears to have been a real object emitting brilliant, corruscating light which descended into an Air Route Traffic Control sector at better than Mach 1, passed within 3 miles of a commercial airway in complete  radio silence, executed an abnormally sharp 180-degree turn at speed and flew away. The probability of a conventional aircraft seems small: the visual appearance and the radar-tracked turn are the key elements of this report, neither of which were within the experience of the observers. Whilst of relatively low strangeness, therefore, the report must be classified unknown.


STATUS: Unknown



19.  DATE: January 13, 1967             TIME: 2200 local           CLASS:R/V  ground radar/
                                                                                                                      multiple air visual

LOCATION:                                   SOURCES: Hynek (1978) 72

Air Traffic Control

Center, Albuquerque, N.M.

                                                         RADAR DURATION: 25 mins.


EVALUATIONS: official not specified


PRECIS: The pilot of a Lear jet flying near Winslow, Arizona, reported a red light at their 10 o'clock position that flashed on and off and several times quadrupled itself vertically, appearing to "retract into itself the lights below the original light". A National Airlines pilot in the area was queried by Albuquerque control tower, and after initially denying any sighting confirmed that they had been watching the object "doing exactly what Lear jet said" approximately 11 o'clock from their position. Albuquerque radar painted an unidentified target in a position consistent with the visual report, and for much of the 25 minutes during which the object was watched from the Lear, Albuquerque maintained radio conversation with the pilot. Whenever the red light was "on", ground radar painted a single target, but whenever it was visually "off" radar painted nothing. Radar apparently did not detect any changes coinciding with the quadrupling of the light. After a while radar showed the target closing range with the Lear, and the tower warned the pilot, who reported that the object began "cat-and-mouse" manoeuvres with his a/c involving rapid accelerations. At 2225 the object began a 30-degree ascent with great acceleration and was watched by the Lear pilot for 10 seconds until it was out of sight. At this time Albuquerque radar lost the target from their scope. Both Lear and National declined to officially report a UFO.


NOTES: Much of the significance of this case depends on details of the "catand-mouse" manoeuvres and the degree to which the radar target movements correlated during this episode. Unfortunately this information is lacking.


   The downward "quadrupling" of the light is very suggestive of a multiple inferior mirage due to highly stratified atmospheric conditions, and celestial bodies can appear dramatically reddened, particularly when near setting. Since the critical grazing angle for an optical mirage is on the order of 0.5 degree this would presumably indicate a light source above the horizon for an aircraft at altitude, and would require the same (vertical) viewing angle from both aircraft. Thus Lear and National need to have been at roughly similar flight altitudes with, probably, a bright celestial body near the horizon. The visual disappearance of the object might be due to its setting below the critical angle, and the rapid "cat-and-mouse" movements of the object (in the absence of detailed description) could be due to sudden excursions of the mirage image (on the order of 1 degree) due either to movements of the aircraft relative to the refractive layer or to local discontinuities in the layer. Unfortunately we do not know the relative altitudes of the two aircraft, or the true azimuth at which the light was observed. However, it can be noted that the radar target which appeared to confirm the object near Winslow would have been due west from Albuquerque and thus not necessarily inconsistent with the azimuth of a setting star or planet viewed due west from Winslow. The same sharp inversion/lapse  strata responsible for such a mirage might be expected to favour anomalous propagation of radar energy and thus the possibility of false echoes.


   There are some problems with this hypothesis, however: 1) During 25 minutes of observation a celestial body above the western horizon would have declined by some 6 degrees, or at least 10 x the critical grazing angle for a mirage, and this makes some unlikely demands on the changing altitudes of the mirage layers and the two aircraft over the duration of the sighting; 2) to keep a celestial body in view for 25 mins the Lear was presumably flying a roughly straight course, during which it probably covered on the order of 100 miles at least - a great distance over which to remain in the same inversion domain; 3) the visual departure of the object, moving upwards at a 30-degree angle for ten seconds at a considerable angular rate, is inconsistent with the optical geometry of any mirage; 4) the repeated flashing of the light on and off suggests an intermittent superior mirage of a celestial body otherwise invisible below the horizon, which is at odds with the consistent downward multiplication of the image suggesting an inferior mirage of a source above the horizon.


   An intermittent source would more aptly explain the flashing off and on, such as a beacon on a radio mast, which would also to some extent evade the problem of maintaining the critical mirage angle for many minutes. However, there is also the general question of the repeated simultaneous radio and optical disappearances of the source: this cannot be explained by an intermittent ground light, and optical disappearance of a celestial body due to the Lear's altitude departing from the optimum mirage angle or flying in and out of localised inversion/lapse domains cannot explain simultaneous signal loss at the radar site. In general it might be noted that the rather extreme atmospheric stratification required for the multiple mirage images would be expected to generate a great deal of AP clutter, and is not usually so anisotropic as to generate a unitary target over a narrow range of azimuths for 25 mins. In summary, the radiooptical AP hypothesis is superficially attractive but conjectural, and suffers from several serious deficiencies.


   Other explanations of the radar target have to address the simultaneous radio-optical disappearances, which argue strongly for a real radar-reflective body. The object would be an anisotropic reflector and emitter - that is, an object with a high radar aspect-ratio in elevation (i.e., side-on:tail-on), zigzagging, rotating, or oscillating, and carrying a light which was visible to Lear only when it presented its greatest radar cross-section to Albuquerque. One could imagine a slowly spinning balloon with an underslung radar-asymmetrical instrument package bearing a red running light, if this could explain 25 minutes of jet-pursuit. A very large research balloon at high altitude over the horizon might be "pursued" for 25 minutes, and (improbably, given small radar crosssection at extreme range) might be painted by second-trip returns which displayed it in spurious proximity to the Lear over Winslow. But this could not explain the high-acceleration 30-degree visual ascent and disappearance, and the lights required to be carried by such balloons during night launches would hardly be prominent at the implied distant ground range and float-altitude of over 100,000'.


   The illusion of a high-acceleration manoeuvre might be created by a small weather balloon near the a/c, but such a balloon could not be pursued at jet speed for 25 minutes. Furthermore weather balloon lights are not red; the quadrupling of the light would still require the superadded improbability of a rare  optical mirage with a fortuitously maintained altitude relationship between the aircraft, the rising balloon and a slowly canting inversion layer; and the final radar-visual disappearance would remain unexplained and coincidental.


   Visually, a reddish light could be explained as the tail-pipe of a jet, and periodic disappearance could relate to a circling or zig-zagging flight pattern which would present a changing aspect with a factor 5 or 10 fluctuation in radar cross-section (10-20 sq. m. down to 2-3 sq. m. for a small fighter). Close to the operational maximum range of the set, the returned signal might drop below the noise threshold as the a/c turned tail-on, and the distance between Albuquerque & the area of Winslow is >200 miles which would be consistent with the action occurring near the limits of an ATC surveillance radar. On this hypothesis the Lear would have been proceeding N or S with the jet ahead, tail-on to the Lear and side-on to the radar whenever it was visible. Such a jet could explain the final ascent and radar/visual disappearance by a climb and turn, tail-on to the radar and out of the pattern. This hypothesis is speculative, however, without knowing the frequency of the light's on-off cycle, the Lear's heading, the displayed speeds of the radar target, and the nature of the "cat-and-mouse" episode. 25 minutes is very a long time for a military jet to be flying at high speed (ahead of the Lear) in such an unusual fashion. Finally, the repeated quadrupling of the red light observed from two aircraft with only a single target appearing on radar is entirely unexplained without recourse to a superadded mirage phenomenon which is itself very rare and which renders the whole scenario too improbable to be convincing.


   In conclusion, the raw visual description alone is strongly suggestive of mirage, although most other features of the case - qualitative and quantitative - argue against mirage as normally understood, and the simultaneous on/off radar-visual periodicity confirmed by radio between the observers as it was happening does argue quite strongly that the radar target and visual object(s) were related. The case should therefore be classified as "unknown" pending further investigation.


STATUS: Unknown



20.  DATE: November 8, 1975    TIME: 0053 MST            CLASS: R/V ground radar/
                                                                                                                            ground visual

LOCATION:                                      SOURCES: Fawcett & Greenwood 30

Malmstrom AFB                                                Klass (1983) 101


                                                            RADAR DURATION: unspecified



PRECIS: National Military Command Center (NMCC) "Memorandum for the Record", 0600 EST, November 8 1975, subject: "Unidentified Sightings":


1) From NORAD Command Director: At 0253 EST [0053 local] 8 Nov, Malmstrom AFB, Montana received seven radar cuts on the heightfinder radar at altitudes between 9,500 and 15,500 feet. Simultaneous ground witnesses observed lights in the sky and the sound of jet engines similar to jet fighters. Cross-tell with FAA revealed no jet aircraft within 100 NM of the sighting. Radar tracked the objects over Lewistown, Montana, at a speed of seven (7) knots. Two F-106 interceptors from the 24th NORAD Region were scrambled at 0254 EST [0054 local], and became airborne at 0257 EST [0057 local]. At the time of the initial voice report, personnel at Malmstrom AFB and SAC sites K-1, K-3, L-3 and L-6 were reporting lights in the sky accompanied by jet engine noise.


2) 0344 EST From NORAD Command Director. Objects could not be intercepted. Fighters had to maintain a minimum of 12,000 feet because of mountainous terrain. Sightings had turned west, increased speed to 150 knots. Two tracks were apparent on height-finder radars 10-12 NM [nautical miles] apart. SAC site K-3 reported sightings between 300 feet and 1000 feet, while site L-4 reported sightings 5 NM from [NW of] their position. Sightings disappeared from radar at position 4650 N/10920 W at a tracked speed of three (3) knots.


3) At 0440 EST, NMCC initiated contact with the NORAD Command Director who reported the following: at 0405 EST [0205 local], Malmstrom receiving intermittent tracks on both search and heightfinder radars. SAC site C-1, 10 NM SE of Stanford, Montana, reported visual sightings of unknown objects.


At this time, as noted in a subsequent NORAD report to NMCC logged at 0522 EST that morning:


At 0405 EST [0205 local] SAC site L-5 observed one object accelerate and climb rapidly to a point in altitude where it became indistinguishable from the stars.


The main report continues:


 0420 EST [0220 local]: Personnel at 4 SAC sites reported observing intercepting F-106s arrive in area; sighted objects turned off their lights upon arrival of interceptors, and back on upon their departure. 0440 EST [0240 local]: SAC site C-1 still had a visual sighting on the objects.



NOTES: There are some insignificant differences in the transcription of this message in the two sources. The only material ones are in  para. 2, where Klass notes a range and bearing for the L-4 visual (interpolated above) omitted by Fawcett & Greenwood, and appears himself to misquote the minutes of latitude for the radar coordinates. (It should also be noted that F & G give a separate narrative of what appears to be the same sequence of events at Malmstrom on the same date [source 30, para.3] but with different times, altitudes and SAC site locations. The source of this confusion is uncertain.)


   NORAD reported to the NMCC Deputy Director for Operations that the possibility of height-finder tracks being caused by auroral ionisation had been considered and rejected after a check with weather services "revealed no possibility of Northern Lights." The 0522 EST addendum to NORAD's initial reports, in part interpolated above, reads in full as follows:


At 0405 EST SAC site L-5 observed one object accelerate and climb rapidly to a point in altitude where it became indistinguishable from the stars. NORAD will carry this incident as a FADE remaining UNKNOWN at 0320 EST [0120 local], since after that time only visual sightings occurred.


   This is the extent of the known official evaluation. The meaning of FADE is uncertain: Klass interprets it as "radar target fading out"; F & G also suggest this, but add that another Air Force code-term, "Faded Giant" meaning an incident involving tampering with nuclear weapons, might be relevant in the context of a Sabotage Alert situation. However, in the context of the NORAD message neither of these interpretations is convincing, and FADE is probably an acronym.


   Klass interprets this 0522 EST message as indicating that NORAD had since concluded that the "intermittent" search and height-finder radar tracks being reported at 0205 local were caused by anomalous propagation conditions. This is quite possible, if speculative given that the message is hardly unambiguous. But on this interpretation 0120 local would presumably be the time of disappearance of the two earlier radar tracks described in para. 2 above, and it is certainly useful to consider the case as two distinct sequences of events.


   Accepting that NORAD had discounted the 0205 radar tracks, Klass proposes that concurrent and subsequent visual reports were of bright celestial bodies. He notes that Venus was "particularly bright", rising about 0230 local time. Reports of the objects "turning off their lights on arrival of the interceptors, and back on again upon their departure" he interprets as due to observers focussing their dark-adapted eyes on the "intense glow" of the F-106s' jet exhausts and being temporarily distracted from the "distant" celestial objects which "would be much fainter and, comparatively, dark." (source 103-4) This is a little strained, however. The report does state (although brevity breeds ambiguity) that personnel at four separate missile sites described this behavior: how many would  be looking up the jet-pipes of the F-106s, and for what proportion of their unknown flight paths? Further, para. 2 states that the mountainous terrain forced the interceptors to fly above 12,000': how "intense" is a jet exhaust viewed at a slant range of several miles, as compared with a "particularly bright" Venus? Klass's hypothesis may be correct, but it is not without some supposition.


   As regards the 0205 radar tracks, these may have been exactly or approximately concurrent with visual sightings from SAC site C-1; and if they were exactly concurrent they may or may not have been consistent with the reported visual position and movement of the "unknown objects". With so little information the report cannot be treated as a radar-visual incident. There is also insufficient information to diagnose the target(s) as anomalous propagation: if, for example, the target detected on search radar correlated with the heightfinder indication, then AP might be less attractive because such effects are frequency-dependent and the two instruments would probably operate at different frequencies. The description of both displayed targets as "tracks" may suggest a coherent sequence of paints, or multiple random blips on the two scopes. It should be noted, however, that "intermittent" tracking is not of itself diagnostic of AP as Klass implies: a real radar-reflective target can be painted intermittently for various reasons including nulls between radar lobes, variations in aspect, variations in range, variations in altitude near the bottom of the beam, weather, shadowing, and ground clutter.


   Turning to the earlier events the picture appears to be slightly more coherent, and if NORAD's apparent disregard of the radar tracks after 0120 local means that they had been explained as AP, then by the same token its retention of the earlier tracks as UNKNOWN implies that these had not. Klass appears to come to the same conclusion, and suggests that these "few intermittent radar targets" (source 101) and "very slow-moving radar targets" (source 103) could have been due to migrating flocks of birds. It is true that even single birds could be detected by sensitive search radars, and flocks can have an integrated radar cross-section as large as an aircraft. But two points need to be made:


   1) Klass's statement that these earlier targets were "intermittent" should be ignored as the insinuation it is. They are nowhere stated to have been intermittent, and If we extract the radar events and times from the report in clear sequence we have the following reconstruction:


0053: height-finder displays targets between 9,500' and 15,500'. During the next minute, personnel check flight plans with the FAA, radar displays the targets moving over Lewistown at 7 knots, and NORAD considers scrambling interceptors.


0054: NORAD issues scramble authority.


0057: 2 F-106s airborne and vectored towards targets, but could not fly safely below 12,000' and were unable to intercept. Meanwhile two targets were being tracked, 10-12 miles apart, which turned onto a W heading and accelerated to 150 knots, eventually slowing to 3 knots.


0120: the targets disappeared from radar in the vicinity of the 8000' Big Snowy Mountains, some 20 miles S of Lewistown.


 There are many questions raised by this narrative, but there is no suggestion that the radar tracks were "intermittent".


   2) Birds might account for targets at 7 knots, but could not then accelerate to 150 knots ( >170 mph) and decelerate again to 3 knots without transiently encountering severe hurricane-force winds, and the indicated target altitude on the height-finder at this time was evidently some way below the minimum safe 12,000' level of the F-106s since it was for this reason that the "objects could not be intercepted". This is not inconsistent with concurrent visual estimates of < 1000', which cannot be relied upon as accurate but do indicate low altitude. Winds on the order of 150 mph at only a few thousand feet, in clear, starry conditions conducive to flying, are not to be thought of. Moreover, the bird hypothesis fails to address concurrent visual sightings of lights and engine noise (reported, it should be emphasised, before the interceptors were launched).


   It would make more sense to interpret such targets as multiple-trip returns from aircraft flying beyond the unambiguous range. It would be possible for such echoes to display spuriously slow speeds changing proportionally to the tangential vector. But again the concurrent visual and aural reports are inexplicable in terms of jets which would have to be at second-trip, or more probably > thirdtrip ranges, as required both by the gross speed distortion and by the absence of any known jets within 100 nautical miles.


   It is noteworthy that "at the time" when the NORAD Command Post received "the initial voice report" from the radar site, "simultaneous" reports were being received from Malmstrom AFB and 4 SAC missile sites of "lights in the sky accompanied by jet engine noise." Personnel plainly believed that the targets were jet aircraft (a sound very distinct from helicopter rotor noise), which is why they queried the FAA about jets in the area. And this is the nub of the incident: jets were heard, lights were seen, and radar showed uncorrelated targets simultaneously in the same area: yet Malmstrom had no jets in the area; according to the FAA there were no other jets in the area; and there are very few jets in the world even today that can fly at 3 knots. (Spuriously slow displayed speeds are possible briefly on a surveillance PPI if an a/c on an inbound radial heading were to climb tangentially to the antenna, thus maintaining similar slant range; but probably neither repeatedly nor for extended periods. The same anomaly cannot occur with a height-finder, however, whose fan beam scans in elevation.)


   The absence of clearly reported search radar paints at this time is noteworthy but inconclusive. In mountainous terrain there would be a groundclutter problem, and the search PPI would certainly have been fitted with MTI (Moving Target Indicator) or analogous signal processing designed to suppress stationary ground clutter. This system could also suppress targets moving at only 3-7 knots. The height-finder's horizontal fan beam, scanning between operatorselectable elevation limits, does not constantly radiate high levels of groundincident energy and so does not have the same permanent clutter problem, which means that it can operate with relative effectiveness without the use of MTI. It is therefore possible that these very slow targets could be preferentially detectable on the height-finder. Search radar may have displayed the targets during part of this incident, since they were reported at 150 knots for a time, but this is far from clear.


    In summary, some later events of the night are ambiguous and could have been misinterpretations of astronomical or other phenomena, although this is conjecture and open to some criticism. The initial radar/visual/aural detection of some kind of lighted, apparently jet-powered aircraft is convincing, however, and the failure of SAC Malmstrom, NORAD and the FAA to identify any aircraft, either by radio, by transponder codes, by interception or by flight plan, is quite puzzling. The implied performance of the aircraft is also extraordinary for any fixed-wing jets other than vertical takeoff and landing (VTOL) aircraft, which would have to be U.S. or Canadian military and thus presumably known to NORAD. Helicopters would better fit the performance, but personnel at several sites independently reported identifying the sound of jets, not rotor noise. There is no obvious explanation of these facts, and some weight has to be given to NORAD's decision to carry this phase of the incident as "UNKNOWN". The reports that the objects sounded like jets certainly invite the legitimate suspicion that they may have been jets, despite these counterindications; but the balance of the evidence argues quite strongly that they were not jets, and subsequent visual reports (with ambiguous radar corroboration) from several sites, describing objects with unusual lighting and flight patterns, do borrow some added credibility from that conclusion.


STATUS: Unknown



21.  DATE:  September 19, 1976          TIME: 0030 local              CLASS: R/V  air radar/

                                                                                                                            ground visual

LOCATION:                                         SOURCES: Klass (1983) 111

Nr. Tehran,                                                               Fawcett & Greenwood 82


                                                               RADAR DURATION: unspecified

EVALUATIONS: No official


PRECIS: The principal source for this case is a memorandum-for-the-record prepared by Lt. Col. Olin R. Mooy, USAF, executive officer to the chief of the USAF section, Military Assistance & Advisory Group (MAAG), Tehran. The report contains information supplied by Iranian officials in addition to details obtained in a debriefing of one of the Imperial Iranian Air Force (IIAF) aircrews involved, which was attended by Mooy and Colonel J. R. Johnson, USAF, at the invitation of Iranian officials. The debriefing was also attended by, amongst others, Lt. Gen. Abdullah Azerbarzin, IIAF Director of Operations. The debriefing took place on September 19, the day of the incident. Mooy's report was distributed to several US agencies, and copies classified CONFIDENTIAL (some with minor edits in prefatory paragraphs) appear in the files of the State Department, CIA, USAF and DIA (Defense Intelligence Agency), the latter with an appended Defense Information Report Evaluation. The complete version follows:


  1. At about 12:30 AM 19 September 1976 the IIAF Command Post received a telephone call from the ADOC [Air Defense Operations Center] representative at Mehrabad [a joint civil-military airport near Tehran]. He said that Mehrabad had received four telephone calls from citizens living in the Shemiran area [of Tehran] saying that they had seen strange objects in the sky. One lady described them as a kind of bird, while another lady said, "Please tell this helicopter with a light on to get away from my house because I'm scared." (There were no helicopters airborne at the time.) The citizens were told it was probably stars.

  2. The Command Post called Brigadier General Yousefi, assistant deputy commander of operations. After Yousefi talked to Mehrabad tower and determined Babolsar and Shahroki radars did not have the object, he decided to look for himself. He noticed an object in the sky similar to a star but bigger and brighter. He decided to scramble an F-4 from Shahroki to investigate.

  3. The F-4 took off at 01:30 AM and proceeded to a point about 40 NM north of Tehran. Due to its brilliance the object was easily visible from 70 miles away. As the F-4 approached a range of 25 NM he lost all instrumentation and communications (UHF and Intercom). He broke off tghe intercept and headed back to Shahroki. When the F-4 turned away from the object and apparently was no longer a threat to it the aircraft regained all instrumentation and communications.

  4. A second F-4 was launched at 01:40 AM. The backseater [radar operator] acquired a lock-on at 27 NM, 12 o'clock high position with  the Vc (rate of closure) at 150 MPH. As the range decreased to 25 NM the object moved away at a speed that was visible on the radar scope and stayed at 25 NM.

  5. The size of the radar return was comparable to that of a 707 tanker. The visual size of the object was difficult to discern because of its intense brilliance. The light that it gave off was that of flashing strobe lights arranged in a rectangular pattern and alternating blue, green, red and orange in colour. The sequence of lights was so fast that all colours could be seen at once.

  6. The object and the pursuing F-4 continued a course to the south of Tehran, when another brightly lighted object, estimated to be 1/2 to 1/3 the apparent size of the moon, came out of the original object. This second object headed straight towards the F-4 at a very fast rate. The pilot attempted to fire an AIM-9 missile at the object but at that instant his weapons-control panel went off and he lost all communications (UHF and Interphone). At this point the pilot initiated a turn and negative-G dive to get away. As he turned the object fell in trail at what appeared to be about 3-4 NM. As he continued in his turn away from the primary object the second object went to the inside of his turn, then returned to the primary object for a perfect rejoin.

  7. Shortly after the second object joined up with the primary object another object appeared to come out of the other side of the primary object going straight down, at a great rate of speed. The F-4 crew had regained communications and the weapons-control panel and watched the object approaching the ground anticipating a large explosion. This object appeared to come to rest gently on the earth and cast a very bright light over an area of about 2-3 kilometers.

  8. The crew descended from their altitude of 26M [26,000'] to 15M [15,000'] and continued to observe and mark the object's position. They had some difficulty in adjusting their night visibility for landing so after orbiting Mehrabad a few times they went out for a straight-in landing. There was a lot of interference on the UHF and each time they passed through a Mag. bearing of 150 degrees from Mehrabad they lost their communications (UHF and Interphone) and the INS [Inertial Navigation System] fluctuated from 30-degrees to 50-degrees. The one civil airliner that was approaching Mehrabad during this same time experienced communications failure in the same vicinity (Kilo Zulu) but did not report seeing anything.

  9. While the F-4 was on a long final approach the crew noticed another cylinder shaped object (about the size of a T-bird [a small jet trainer] at 10 NM) with bright steady lights on each end and a flasher in the middle. When queried, the tower stated there was no other known traffic in the area. During the time that the object passed over the F-4 the tower did not have a visual on it, but picked it up after the pilot told them to look between the mountains and the refinery.

  10. During daylight the F-4 crew was taken out to the area in a helicopter where the object apparently had landed. Nothing was noticed at the spot where they thought the object landed (a dry lake bed), but as they circled off to the west of the area they picked up a very noticeable beeper signal. At the point where the return [sic] was loudest was a small house with a garden. They landed and asked the people within if they had noticed anything strange last night. The people talked about a loud noise and a very bright light - like  lightning.

  11. The aircraft and the area where the object is believed to have landed are being checked for possible radiation. More information will be forwarded when it becomes available.


NOTES: Whatever further information may have "become available" is unfortunately not available in the public domain. According to Fawcett & Greenwood, "reliable" US govt. sources acknowledged privately that the official file on this case was 1" thick, but no agency has admitted possession of documents pursuant to FOIA requests. Whilst this is currently hearsay, there does seem to be no good reason why information which was promised should not have been forwarded; and if it was not volunteered by MAAG, there is at least some evidence that it would have been actively sought.


   The only known official US response to the Mooy message is a one-sheet DIA Defense Information Report Evaluation, which allows an analyst to check multiple-option replies to standard questions on the reliability, value and utility of the information with a section for general remarks. The DIRE form indicated that the DIA analyst processing the report considered it to have been "Confirmed by other sources"; that he thought its value to be "High", which the form defines as "Unique, Timely, and of Major Significance"; and that he thought the information was "Potentially Useful". Under "Remarks" the analyst wrote:


An outstanding report. This case is a classic which meets all the criteria necessary for a valid study of the UFO phenomenon:

a) The object was seen by multiple witnesses from different locations (i.e., Shemiran, Mehrabad, and the dry lake bed) and viewpoints (both airborne and from the ground).

b) The credibility of many of the witnesses was high (an Air Force general, qualified aircrews, and experienced tower operators).

c) Visual sightings were confirmed by radar.

d) Similar electromagnetic effects (EME) were reported by three separate aircraft.

e) There were physiological effects on some crew members (i.e., loss of night vision due to the brightness of the object).

f) An inordinate amount of maneuverability was displayed by the UFOs.


   Once again, no further information on the progress of the report through the DIA evaluation chain is available. But given that it was flagged as prima facie of potentially major significance one would expect some attempt to be made to secure an update, either actively through MAAG or, more probably, through inhouse intelligence channels and such sources as NSA communications intercepts. There is thus every possibility that more, unacknowledged hard-copy has existed on this incident, and Fawcett & Greenwood's "reliable sources" may well have been correct. It might be noted that the DIRE form's commentary on the original message states: "Confirmed by other sources", which would also be consistent with this inference.


   However, the MAAG memo is the only available direct official source, supplemented by newspaper stories which have only limited value. The following analysis is based pricipally on the Mooy document, with additional reference to published quotes from a transcript of the F-4s' radio communications with Mehrabad Tower. [Note: The most influential public analysis of the case was  published by Klass, and since he proposes a scenario - quite widely respected - which purports to undermine the reliability of the report as a whole, a detailed commentary on his 11-page polemic is included as an appendix to this entry.]


   The core episode is the interception by the second F-4. The radar target in this case appears to have had a very strong scope presentation, comparable to a Boeing 707. A specific estimate of radar cross-section is difficult to derive from this comparison, owing to typical fluctuations due to aspect of as much as two orders of magnitude; but assuming the operator to have meant that the target compared with a 707 under similar conditions, then given that the target was moving ahead of the F-4 we have a tail-on figure of between 20-50 square metres. A 707's side-on cross section, however, might exceed 1000 square metres, so that the above figure should be taken as indicating only a rough minimum due to the uncertainty about the operator's assumptions.


   This strong target was not fleeting, but appears to have been held for a period somewhat in excess of 1 minute. After the initial lock-on at 27 nautical miles range the F-4 closed with a Vc of 150 mph to 25 n. miles, which alone would have taken some 50 seconds. Subsequently the Vc reduced to zero and the target "stayed at 25 NM" for an unspecified period. According to an account of the pilot's UHF transmissions it was during this period that he armed his weapons and made ready to engage:


[The pilot] told the control tower that it [the target] had reduced speed. The pilot said the plane was working well and he was preparing to fire missiles at the UFO. After a moment's silence he said he had seen a 'bright round object, with a circumference of about 4.5 metres, leave the UFO.' [Tehran Journal, September 21, quoting transcript of tapes released to Persian-language Ettela-at]


   The debriefing record states that this object had a visual angular subtense of between 10 and 15 minutes of arc, but although angular measure must be more reliable than subjective estimates of "circumference" there is insufficient detail to infer anything from these figures. If, as the raw account appears to imply, this angular measure applies to the object as it appeared on separation from the primary object, and if the primary object was at the time at a range of 25 miles, then the secondary object would be on the order of 500 feet in diameter. This conflicts dramatically with the value quoted (admittedly second-hand) from the control tower tapes, and probably suggests that the estimate of angular subtense relates to the period when the object had approached the F-4. The only distance value quoted here is the 3-4 miles at which the object appeared to trail the F-4. At 3 miles the subtense implies an object some 50 feet or more in diameter, with a circumference on the order of 150 feet, which is still in excess of the quoted size estimate by a factor of 10. Whilst one might assume that a typographical error somewhere in the chain of translation and quotation has changed "45 metres" to "4.5 metres", which would rather too neatly tie up these figures, it is preferable to accept that the crew misjudged the size and/or angular subtense of the secondary object. Such misjudgements are typical of visual reports even from quite skilled observers. All that should be concluded is that the secondary object appeared to have noticeable extension (unlike a stellar point-source) and was rather bright.


   It is not specifically stated that this secondary object was also detected on radar. A radar target would not be indispensable for fire-control purposes, the  AIM-9 "Sidewinder" being a fire-and-forget infrared-guided missile. (One version of Sidewinder, the AIM-9C, was radar-guided, but it was withdrawn from service due to unreliability and it is safer to assume that the missiles in question here were a commonly-used IR-guided version.) Radar range information would be desirable in order to usefully deploy the AIM-9 in ideal circumstances, owing to its close air-combat range limitations; but in the present case the object was approaching the F-4 from near dead-ahead "at a very fast rate", and this is far from an ideal circumstance. Seeing something approaching, and knowing that the head-on rate of closure could be extreme, the pilot could be justified in deciding to launch a missile even without the benefit of accurate radar range updates from his backseater. Therefore, although there is no reason to conclude that this target was not on radar, and although the "very fast rate" cited may have been measured on radar, it is also possible that this target was only visual.


   Howsoever, at this point the F-4's weapons-control electronics failed and the pilot, unable to use his missiles, executed an evasive turn and dive, at which point the primary target would presumably have been lost from the scan limits of the AI radar although, again, this is not specifically stated. Nevertheless it is clear that the primary target was held for a period probably well in excess of 1 minute during this episode. It was a strong target comparable to a large jet and was displayed on the scope in a position that at least approximately corresponded with the "intensely brilliant" strobing lights.


   It is possible for airborne radars to display ground targets. If the F-4 were heading N over Tehran during pursuit (as was the first F-4) then two possibilities present themselves as causes of false targets: 1) an isolated high peak of the Alborz coastal range (up to >18,000') could be detected as a large target just within the lower elevation limit of the AI radar; 2) a ship on the Caspian Sea, perhaps detected by anomalous propagation, could present a strong target. However, although the second F-4 must have approached the area from the S or SW (from Shahroki), that it was on a N heading during the pursuit is arguable: the report states that the "object and the pursuing F-4 continued a course to the south of Tehran" (emphasis added). Further, no sea or ground target detected in this way could be displayed moving ahead of the intercepting aircraft. The following points are relevant to these and similar hypotheses.


   During pursuit the aircraft would presumably have been climbing towards its target, since initial acquisition was at "12 o'clock high", and the report states that the F-4 subsequently descended from 26,000' to 15,000', implying that the attempted interception took place at or above 26,000'. Thus, considering the likely rate-of-climb of the F-4 during a minute or so of pursuit, this radar-visual episode would have taken place with the aircraft between about three and five miles high and, for much of the time, in a nose-up attitude. A target displayed at "high" elevation, or with the aircraft nose-up, (inexactitude notwithstanding) is unlikely to be due to superrefractive AP of ground echoes due to the rather narrow grazing angle requirement, even neglecting displayed "airspeeds". If the elevation were only a few degrees then partial reflection of radar energy from a sharp inversion layer above the F-4's altitude could be scattered back from distant ground reflectors; but with the aircraft flying over a ground track of some 10-12 miles (at Mach 1) such an echo would not be expected to display as a distinct spot target - resembling an aircraft and good enough to give a radar lock-on - for more than a minute, given likely inhomogeneities in the inversion layer and the changing reflection efficiency of discontinuous terrain. Direct specular returns from layers or localised domains of  very extreme refractivity can occur, and such specular returns could evade the grazing angle requirement and the problems of discontinuously reflecting terrain; but such phenomena are normally only detectable on very sensitive search radars, and even if a specular clear-air echo could produce a very strong and persistent spot target on a low-power AI radar the target could not move ahead of the pursuing aircraft as described.


   Spurious internal signals or RFI are possible causes of false blips, and where the noise input pattern is such as to simulate a scanned target would be most likely to display essentially linear motion on a radial vector (as in this case) rather than complex non-radial tracks. However the description of target motion is sketchy, and a consistent spot target displayed for a significant duration is far from being the most probable symptom of such effects. According to Klass, IIAF maintenance technicians reported no indication of internal radar faults when the F-4 returned to Shahroki (source 119). Also, the coincidence of a somewhat striking concurrent visual sighting is relevant to all the hypotheses considered above.


   In general, the probability of any such false radar indication occurring during a particular flight must be inherently low - that is, very much less than unity; the probability of a celestial body such as Jupiter (see attached commentary on the analysis by Klass) coinciding with the azimuth of the false target, and exhibiting the reported appearance due to mirage, haze-scattering or extreme convective scintillation, is also much less than unity; and the probability of this scenario will be the still-smaller product of these two fractional values. It must also be considered that the first F-4 may have acquired a radar target (although this is not specifically stated), since the report quotes a range of 25 nautical miles for the object at the point when the intercept was broken off due to communications/electronics failure -  the same range at which the second F-4 experienced the same reported failure. If so then the probability would drop by a further fractional multiple. (The paraphrased newspaper account based on the audio tape of the first F-4's communications with Mehrabad does not clarify this point, although at one point the pilot is quoted as saying: "Something is coming at me from behind. It is 15 miles away . . . now 10 miles away . . . now five miles . . . . . It is level now, I think it is going to crash into me. It has just passed by, missing me narrowly . . . ." This sounds like radar ranging information, but plainly not from the nose-mounted AI radar, and the rearward-facing passive RWR sensors on the F-4Es which made up the bulk of the IIAF Phantom fleet at this time cannot indicate range. The IIAF did have a handful of RF-4E reconnaissance versions with APQ-102 side-looking radar but, other objections apart, these aircraft carried only a small mapping radar instead of the AI radar in the nose and were unarmed. It seems likely that the pilot was offering visual estimates of range.) It is pointless to pursue this exercise quantitatively, but it is legitimate to say that an interpretation which does not rely on improbable coincidence might be more attractive.


   Prima facie the most likely cause of such a target is another aircraft, and concurrent visual observation of an object bearing what might be construed as one or more strobing beacons is possibly support for this hypothesis. The radar operator stated that the target was comparable to a 707 tanker, and air refuelling operations are always brightly lit, so the question arises: could the object have been an air refuelling tanker such as a KC-135 (an adapted 707 airframe) - perhaps part of some US operation which the IIAF were unable to trace? The secondary light appearing to detach from, and then reattach to, the  primary object might be explained as the position lights and/or glowing jetpipe(s) of one or more refuelling aircraft. The vivid strobing colours of the primary object could have been a mirage effect due to an inversion along the line of sight.


   The main problem with this hypothesis is target velocity. The report does not contradict the reasonable assumption that the F-4 was doing its best to intercept a potentially hostile intruder, and would therefore have been using its speed to attempt to close within weapons range (the audio tapes disclose that the first F4 made its approach at Mach 1, but there is no specific airspeed cited for the second F-4). Even at maximum speed a Stratotanker is not capable of much above 450 knots, and would therefore have been going hell-for-leather even during the first phase of the intercept when the F-4 was able to close at a Vc of 150 mph for some 50 seconds. To subsequently pull ahead "at a speed that was visible on the radar scope" and then maintain separation from a pursuing Phantom, capable of better than Mach 2 at altitude, would be impossible for any tanker. There is no propagation mechanism which would cause such a target to be displayed at spuriously high speeds, and it is also true to say that this hypothesis cannot readily cope with other, and rather specific, elements of the visual description - for example, the second "emitted" object which approached the ground and illuminated its surroundings. Generally speaking it is highly improbable that any such military activity would have been taking place over Tehran without the knowledge of the IIAF or USAF officials working with the Military Assistance Advisory Group. If MAAG/USAF did know something then Mooy's report of the incident, and the DIA's response to it, may have been disingenuous, which leaves open the possibility that some more sensitive military activity was taking place.


   It is possible that such a radar target could have been generated by deception jamming techniques. The technical specifications of the Westinghouse radar installed on the IIAF F-4 would be required to evaluate this with confidence, but in 1976 it may have been a conical scan pulse-Doppler system vulnerable to velocity track breaking (which can manipulate the range and hence speed of a false target) and bearing deceptions related to the "inverse gain" jamming which can generate targets at false azimuths on surveillance scopes. By analysing the incoming radar signal and feeding back false frequency-modulated signals, an aircraft equipped with a jamming pod can "steal" its own blip from the attacking radar and create in its place a fake target with spurious bearing, velocity and scope presentation. Such techniques are much more difficult to apply to later monopulse radars, but similar deceptions are effective against most analogue or digital time-domain or frequency-domain systems. The reported disruption of communications and weapons-control functions on the F-4s, as well as UHF on a civil airliner, might superficially suggest that some such jamming deception was involved - perhaps a blind test of a new system in simulated operational conditions. Further circumstantial support for the idea that Tehran's electromagnetic environment was being widely jammed might be drawn from the fact that, according to Klass (source 115), "the Mehrabad radar was inoperative at the time", which might be construed as implying a malfunction. On this hypothesis the secondary objects emitted by the primary target might be interpreted either as infrared flares, deployed in order to decoy the F-4's AIM-9 IR-guided missiles when the target's own radar-warning receivers detected a hostile lock-on, or alternatively as photoflash cartridges or flares dispensed to illuminate the terrain for photoreconnaissance purposes.


    However it would seem unnecessary for the US to test any such system in foreign airspace, and extremely risky for anyone to test it in real combat against lethally-armed interceptors! If it were a covert reconnaissance penetration by an aircraft of a hostile foreign power, the crew would have to be very confident of their electronic/IR defenses to meander around the skies over Tehran for upwards of 60 minutes. A secondary body which appeared to approach the F-4 at speed, fall in trail, then turn back for a "perfect rejoin" with its parent object, cannot be interpreted as a flare without considerable strain, and anyway IR flares are normally deployed in clusters. (Another type of decoy in use at the time was the ADM-20 "Quail", a tiny pilotless jet carried by USAF B-52s. Released from the bomb bay, the Quail carried ECM equipment to simulate a fake B-52 radar signature and could fly for around 30 minutes at 500 mph. It was expendable, however, and obviously was not designed to hang around the parent aircraft, let alone return to it. Numerous other expendable drones and "harrassment vehicles" are known to have been developed for various reconnaissance, ECM and tactical assault roles. A few are recoverable, but not by the parent aircraft.) Furthermore, no covert operation would be advertised with aircraft lighting of "intense brilliance". And finally, whilst jamming of communications and radar are both possible there is, even today (1994), no known EW technology capable of remotely disabling fire-control electronics, which fact leaves this element of the report dangling as an uncomfortable coincidence. In general, the jamming deception hypothesis is a poor fit to the overall sequence of events, and since it itself presupposes some type of unidentified aerial intrusion there appears to be no advantage in pursuing it as an explanation for the reported radar target.


   It was noted above that the Mehrabad radar was reportedly "inoperative" during the incident, for reasons unspecified. It is not unusual for an airport radar to be switched off if there is no expectation of inbound traffic. The Mooy memo states that, according to IIAF assistant deputy commander of operations Brig. Gen. Yousefi, he was informed at some time shortly after 0030 that Babolsar and Shahroki radars (presumably IIAF air-defense radars) "did not have the object" which had recently been reported by civilian observers in the Tehran area. This information relates to a time-frame some while before the launch of the first F-4. Is this reported absence of ground radar confirmation significant?


   Babolsar is actually located about 100 miles NE of Tehran on the Caspian coast, and on the far side of the Alborz Mountains which rise to about 18,000' in the line of sight. Shahroki is about 130 miles SW of Tehran, and assuming normal refractivity (4/3 earth) a 1 lower beam edge elevation would give a radar horizon at this range of some 20,000'. Even a 0.1 horizon would be almost 10,000'. Therefore, assuming that Mooy's phrase, "did not have the object", means that the Shahroki and Babolsar radars were operational yet did not display an uncorrelated target near Tehran at the time of Yousefi's inquiry, then the significance of this report depends on several variables. If a target were at low altitude (say, a few thousand feet) it might well be below the radar horizon. Also, an air-defense search radar would certainly have pulse-Doppler MTI to eliminate stationary ground clutter, and a stationary target (i.e., hovering) could be rejected along with the clutter. There are thus several reasons why a target could be unreported by a radar at Shahroki yet be visible in the sky from Tehran. By far the most likely reasons for extended undetectability would be low altitude or true stationarity. (Certainly, since Shahroki and Babolsar were at different ranges and bearings from Tehran then MTI vagaries such as blind speeds and tangential fades become very unrealistic explanations.) If the visual sightings at this time were of a real, radar-reflective object, therefore, we should expect them to be consistent with an object that was either not moving or at an altitude of no more than a few thousand feet, or both.


   The information is very sketchy indeed. One civilian thought it was a light attached to a helicopter which, it is implied, appeared to be hovering nearby for an extended period since he desired it to "get away from my house", whilst another described "a kind of bird". Brig. Gen. Yousefi described an object "similar to a star but bigger and brighter." A Mehrabad tower controller was quoted (Tehran Journal September 20 1976) as saying that it was flashing coloured lights over the south of the city at about 6000' altitude. Whilst there is obviously very little to be said about these statements, nevertheless they are collectively not inconsistent with an object which was stationary in the sky and/or at low altitude.


   As for the later phases of the incident, the report simply does not state whether or not any IIAF ground radars were involved. (The target range information cited for first F-4 could, in the absence of clear reference to an AI target, be interpreted as having come from GCI radar, but this is speculative.) Note that only in the case of the second F-4's intercept do we have any information about target altitude, where it is implied that the object was by this time at about 26,000', travelling fast, and thus a definite potential ground radar target; but given a launch time of 0140 the F-4's ETA over Tehran at Mach 1 would be about 0155, or a good half-hour after Yousefi's decision to scramble and perhaps as long as 45 minutes after Mehrabad tower informed him by telephone that Babolsar and Shahroki "did not have" a target. It is quite possible that by this time these radars did have a target, but there is no record that Mooy asked about this or that information was volunteered. At the time of Mooy's attendance at the second F-4 crew's debriefing, a matter of hours after the event, it is presumably possible that full reports from (say) Shahroki or Babolsar were currently in preparation, in the process of transmittal, or sitting in someone else's "in" tray, and might well have been amongst the "more information" which Mooy undertook to forward when available, but apparently never did. The absence of reported ground radar confirmation in Mooy's memo therefore raises an unresolved question, but does not constitute probative evidence.


   In summary, the radar-visual core of the incident reduces to an AI lock-on to a strong target, held for upwards of a minute, with a correlating visual observation of strobing coloured lights sufficiently brilliant to impair night vision. The radar target presentation was comparable to a 4-engine jet, with implied maximum airspeed probably well in excess of Mach 1. Such a target is not explainable as birds, insects, CAT, balloons or other wind-borne objects. The probability of superrefractive AP or partial scattering seems low in this case. Random RFI, sporadic internal noise or deception jamming are all possible if improbable explanations of such a target, but none is compelling in the overall context. There is nothing about the primary radar target itself which positively rules out an aircraft, even though indications of a very large radar-reflecting area are somewhat inconsistent with fighter-type performance. In the context of the visual description and the behavior of associated secondary objects, however,  there is no plausible explanation in terms of conventional aircraft. The visual report can be interpreted as a misperception of an abnormally scintillating celestial body and a couple of coincidental meteors, but this seems rather contrived and contradicts several features of the visual report, as well as requiring the added coincidence of an improbable radar anomaly (some aspects of the visual descriptions are further considered in the Appendix to this entry).


   In conclusion, although several peripheral aspects of the incident are difficult to evaluate and some questions about the core radar-visual episode remain unanswered, in terms of the not-insignificant quantity of information available it is judged reasonable to carry the incident as an unknown.




















Commentary on Philip J. Klass's "UFOs Over Iran"

See: Klass, P., "UFOs, The Public Deceived", Prometheus Books 1983, chapter 14.

The following commentary relates to page & paragraph numbers:


p. 113 para. 1: "If the flight crew's report was accurate in all details, then clearly this UFO was outfitted with an exotic weapon that could induce electrical-electronic failure . . . . Yet this posed a curious anomaly: If the UFO did indeed have such a remarkable defense at its disposal, why had it seemingly fired a rocket-missile against the F-4, which already had been rendered harmless? Did this mean that UFOs suddenly had turned aggressive and hostile?"


Comment: The "curious anomaly" seems to be a straw man erected to be knocked down. "Exotic weapons" and "rocket-missiles" are mere science fiction, and the argument is neither logically sound nor pertinent.


p. 113 paras. 2 & 3: "If there were any truth to the oft-repeated claims [that the US military or the government know UFOs to be extraterrestrial] this Iranian incident should have generated an appropriate response. Presumably the USAF would itself have launched an all-out investigation, importing a team of specialists from the United States and the late Shah would have been asked to impose official secrecy to keep all news of the incident out of the press. Yet none of these things happened.[original emphasis]

  "Mooy's memorandum-for-the-record was not even classified (that is, stamped 'Top Secret') in the MAAG files. Later, when a copy was sent back to the U.S. and distributed to a number of agencies . . . [it] was classified "Confidential" - the lowest security level. There was no followup investigation of the incident by the USAF or MAAG personnel, according to Mooy. Nor were there any further MAAG dispatches on the subject from Tehran, although the incident was widely publicised in Iranian newspapers. Perhaps the best indication of how seriously the U.S. government was concerned . . . is that a copy [of the memo] was leaked to NICAP [National Investigations Committee on Aerial Phenomena] soon after it was received in the U.S. . . . .


Comment: Whilst speculation about US government attitudes in hypothetical circumstances is not pertinent to the facts of the case, this theme is relevant to the later development of Klass' argument and therefore must be addressed.


   Firstly, the absence of acknowledged follow-up information from Tehran is a point addressed in the attached case evaluation: this absence is ambiguous, and could be held to support a variety of interpretations. The stated absence of any US investigation is a conclusion based on one interpretation of the fact that no further information on the affair is available. This conclusion depends on the collateral assumption that such investigation would be conducted by local MAAG/USAF personnel, and conveyed in further unclassified dispatches from Tehran. These assumptions are questionable, and indeed conflict with Klass's own  proposition that if US authorities had taken the UFO incident seriously then imported specialists would have been brought in to investigate under a security blanket so tight that total press-censorship, even in Iran itself, would have been an option. This scenario is perhaps a little extreme, but a level of secrecy could be inferred from the fact that when the second F-4 (which had had the major role to play in the incident) returned to Shahroki it was quarantined in an outlying revetment, and local USAF personnel and technical representatives of both McDonnell Douglas & Westinghouse were prevented from approaching it (see later). If something like the scenario which Klass believes ought to have been enacted was in fact enacted, then it would be highly unlikely that local company representatives or local USAF personnel would be invited to participate, and it would be entirely consistent if they were actively excluded. Of course there is no direct evidence that such a secret investigation did occur, which is why Klass states that it did not; but equally, if it was secret then by definition one would not expect there to be direct evidence. As regards Klass's hypothesis that the US would have asked the Shah to impose press censorship in Iran: 1) Klass states that the Shah was in fact not asked, although how he could know this is unclear; 2) all of the Iranian press stories which Klass quotes were published within about 36 hours of the incident - some within about 12 hours, and thus probably in preparation before Mooy was even able to prepare his memorandum - so that these are not counterinstances to the censorship hypothesis; 3) U.S.-instigated press censorship from a later date, even if considered as an option, would probably have been adjudged belated and to little purpose; 4) if any stories were censored it follows that they were not published - i.e., it is impossible to prove a negative; 5) Klass's assertion that censorship is a necessary condition of serious U.S. government interest is unfounded speculation.


   As regards the fact that a copy of the Mooy memo was allowed to "leak" from a US government source, this could be taken to indicate that, as Klass suggests, the memo was not regarded as a highly sensitive document, a conclusion supported by the low-security classification assigned to it by agencies in the US. Whether the fact that the memo was not regarded as highly sensitive should be taken as meaning that the incident was not regarded as very important is another matter. By the time the copies of the memo were being processed through the in-trays of the CIA, DIA etc. the story was already widely known through the Iranian press, including English-language newspapers, who published articles describing all its essential features as early as September 20 - the following day. It is debatable if Mooy's memorandum-for-the-record, prepared subsequent to a debriefing which took place sometime on September 19, was by then even lodged in MAAG files, let alone transmitted abroad. Given that it had not been classified by MAAG at this time, and considering the extent of simultaneous IIAF press contact (partial transcripts of both F-4s' taped radio communications were published almost immediately in the Persian-language Ettela'at and reprinted in English in the Tehran Journal the next day, September 21), the likely estimate of US agencies at a later date would be that the document, which anyway was only a preliminary summary of complex events, had been effectively compromised as a source of secure intelligence. There would be no point in classifying it "Top Secret", and indeed such a move might be counterproductive, only fuelling suspicions of a cover-up. Whether any additional material was in fact covered up is of course impossible to prove without evidence which, ex hypothesi, would be subject to that cover-up. The "national security" exemptions of the Freedom of Information Act allow government agencies the latitude to withhold information from public access by defining it as an issue of "national security", a fact which Klass implicitly concedes when he argues that the availability of even one unclassified memo and the absence of total press-censorship points to a lack of government concern.


p. 114 para.1: "[Major General Kenneth P. Miles, USAF, chief of MAAG, Tehran, forwarded, at Klass's request] a photocopy of the unclassified Mooy memorandum, as well as several articles on the incident . . . . Miles added: 'I share your view that there is no evidence to suggest that the earth is being visited by extraterrestrial spaceships.'"


Comment: Neither the view which Miles endorses, nor the assumptions underlying the view which he and Klass dispute, are pertinent to the facts of the case.


p. 114 para.2: "One of the [Tehran newspaper articles] quoted a Mehrabad airport controller as saying that the UFO was flying at an altitude of about 6,000 feet over the southern part of sprawling Tehran, alternately flashing red, blue and green lights. Yet Mooy's memorandum, based on information offered by the second F-4 crew, said the first F-4 had been 40 nautical miles north of Tehran when that airplane encountered mysterious electrical-electronic problems."


Comment: Klass is incorrect to state that Mooy's memorandum is based only on information supplied by the second aircrew at their debriefing, and there is no justification for the assertion that the description of the first intercept is based on the second-hand recollection of this second aircrew. Klass does this because he wants to suggest, and later develop, the idea that the second aircrew were untrained, sleepy, confused and prone to make mistakes. By nurturing the impression that the entire memo rests on their recollections, he is then later free to imply that several details are questionable. The information noted by Mooy in his paras. 1, 2 & 11, for example, plainly comes from other IIAF documents, or operations officials - such as Director of Operations Lt. Gen. Azerbarzin himself - who were conducting the debriefing, and details of the first intercept may presumably have come from the same sources.


   The Mehrabad controller's statement re-quoted by Klass comes from a newspaper story. Klass will elsewhere, and correctly, decline to credit newspaper stories in preference to the official memorandum, and should in conscience do so here.


   However, granting the accuracy of the newspaper story insofar as it goes, the indicated contradiction is false. Firstly, the sequence of ground and air observations covered by the Mooy memo spans something like 1 hours, and the newspaper quotation does not state the time at which "the UFO" was flying over the south of Tehran (Klass's adjective, "sprawling", is a journalistic device to maximise the impression of distance). Secondly, even if the quoted visual sighting over the south of Tehran does relate to a time when one of the F-4s was in pursuit there is no justification for the assumption that it was the first F-4; and according to Mooy's memo the second F-4 "continued a course to the south of Tehran" in pursuit of the object. Thirdly, the first visual sightings (there were many) were relayed by Mehrabad tower to the IIAF Command Post at 0030; the first F-4 took off from Shahroki (130 miles SW of Tehran) at 0130; and at Mach 1 the aircraft would have taken until about 0145 to reach the intercept point 40 miles N of Tehran, or nearly 1 hours after the first visual reports from the Shemiran area. Thus, there is no suggestion of simultaneity and the contradiction  proposed by Klass does not exist. If the same "UFO" first sighted visually was subsequently intercepted by the first F-4 the implication is of an object heading N from Tehran at this time, which is consistent with:


p. 114 para.3: ". . . Based on these tapes [of the first F-4's radio communications with Mehrabad as paraphrased in a newspaper article] the first F-4 flew over Tehran at the speed of sound . . . and the pilot called the Mehrabad tower when he first spotted the UFO. [Lieutenant] Jafari drescribed the UFO as being 'half the size of the moon . . . It was radiating violet, orange and white light about three times as strong as moonlight.' Although the pilot was flying at maximum speed, he said that 'on seeing him coming the UFO increased its speed,' that is, he was unable to close on the bright light."


Comment: Note that the F-4 approaches over Tehran, that is, on a N heading in pursuit of the object, which appears to accelerate ahead of him. Note also, however, that this account is based on a partial quotation of an article in the English-language newspaper the Tehran Journal, which itself is quoting in translation an article from the Persian-language paper Ettela'at which, in turn, is a blend of quotation and paraphrase is from a transcription of the audio tapes.


p. 114 para.4 "[According to the same article] Mehrabad tower told him [Jafari] to return to base if he could not close on the object and the pilot agreed to do so, but a few moments later he radioed: 'Something is coming at me from behind. It is 15 miles away . . . now 10 miles away . . . now 5 miles . . . . It is level now, I think it is going to crash into me. It has just passed by, missing me narrowly . . . .' The newspaper said that 'the disturbed voice of the pilot . . . then asked to be guided back to base. It was at this time that a second plane was ordered to take off.' This account indicates that there was not any mysterious malfunction of the electrical-electronics equipment aboard the first F-4, contrary to the account in the Mooy memorandum. The explanation for this discrepancy is that Mooy and Johnson sat in on the debriefing only of the second F-4 crew, and this misinformation must necessarily have resulted from the fact that the two crews had not had a chance to compare notes prior to the debriefing."


Comment: Again we have the suggestion that an error, if error there was, can be laid at the door of the second F-4 crew. There is no basis for this in the Mooy memorandum. Mooy states that the first F-4 lost instrumentation and communications and the error, if error there was, could as well have been Mooy's. If Klass were right and the aircrews "had not had a chance to compare notes" then the information stated by Mooy in the same paragraph - that the first crew had visually acquired the object at 70 miles and closed to 25 miles  - could not have come from the first F-4 crew via the second F-4 crew. Even if we suppose that all the information in this paragraph did come from the second F-4 crew, then there are really only four possibilities: a) they were relaying accurate information from the other crew or an intermediate source; b) they were relaying inaccurate information in good faith; c) they were lying; d) they were the source of the information but it was misunderstood, by Mooy and/or someone else. If the newspaper account is to be taken as the whole truth, then they were not relaying accurate information. Presumably the airmen did not  make up a story out of whole cloth, so that if the electronics malfunction did not occur, and if they stated that it did, then someone else gave them inaccurate or ambiguous information. Alternatively, information relating to the second aircrew's own intercept may have been mistakenly interpolated by Mooy into his account of the first intercept. Wherever the information originated there is no basis whatever to infer any failure of judgement or honesty on the part of the debriefed aircrew, and the newspaper story should be interpreted with caution.


p. 114 para.4 cont.: "It also is important to note that the glowing object that Lieutenant Jafari reported seeing was 'coming at me from behind.' Since he, presumably, was chasing the bright light in the sky at the time, which would have been dead-ahead of him, the object coming at him from the rear seemingly was quite unrelated to the object he was chasing."


Comment: This is "important" to Klass because he regards it as inconsistent or in some other way diagnostic of error or untruth. Why this should be so is unclear; if Jafari is reporting two separate UFOs, then he is reporting two separate UFOs. But there are other interpretations: Jafari could have meant, for example, that a secondary object was 'coming from behind' the primary object, not from behind his aircraft, similar to the behavior later reported by the second F-4; the context of the translated quotation would have to be studied to exclude this interpretation. In fact, however, the sequence of events bears closer scrutiny. The pilot was advised to turn back to Shahroki and stated that he was complying, then "a few moments later" he reported the object coming from behind. Given the chain of quotation, translation and interpretation leading up to this account, Klass's "few moments" could well have been enough time for the pilot to have initiated his turn before reporting the object on his tail. There is no justification for Klass's assumption that he was still watching the primary object "dead-ahead" at this moment.


p. 115 para.1: [According to the Tehran Journal's paraphrase of its translation of the second F-4's radio transcript] 'the pilot reported having seen the UFO and told the control tower that it had reduced speed. The pilot said the plane was working well and he was preparing to fire missiles at the UFO. After a moment's silence he said he had seen a "bright round object, with a circumference of about 4.5 meters, leave the UFO." A few seconds later the bright object rejoined the mother craft and it flew away at many times the speed of sound.'


Comment: Klass points out that there is no mention here of the communications and weapons control failure reported by the aircrew in their debriefing, nor any mention of the radar contact so specifically described in the same debriefing. In particular he argues that if the F-4 had lost UHF contact with the tower as reported it would have interrupted these radio communications. As Klass later admits (p.116 para.1) it must be "prudent" to give more credence to the official memorandum of the debriefing than to a newspaper account. It is therefore unclear what point he is making. However, for the sake of argument it should be noted that according to the debriefing the electronic failure did not occur until after the secondary object described above had approached the F-4, and thus is outside the timeframe of the radio talk quoted. The fact that the newspaper chooses to collapse the entire sequence of subsequent events into one bland sentence is hardly evidence of anything except the perennial failings of  journalese. The newspaper paraphrase of the tapes may add colour to the first-hand debriefing record, but it is plain that it should not be taken as a complete and authoritative source, omitting as it does a great many other aspects of the incident, and conflicting as it does with other newspaper stories quoting other "official sources", vide:


p. 116 para.1: "Despite this disclaimer from an unidentified 'official source,' it seems prudent to put more credence in the Mooy memorandum, since it is based on notes taken during the debriefing of the second F-4 crew, although it is clear from the Mehrabad tower tape recording that the second crew's account of what happened to the first F-4 contains serious errors."


Comment: Klass has just quoted at length an article in the newspaper Kayhan International, September 21, which, on the basis of an unattributed government statement, contradicted almost everything that other newspapers had so far reported about the affair as well as a great deal of the Mooy memorandum (which at this time was not yet in the public domain). According to this account, all that happened was that one of the F-4 pilots saw a light which soon disappeared; there were no electronic outages, no secondary objects, no pursuit of the aircraft, and neither pilot made any attempt to open fire. The account of radio communications published in Ettela'at 'left the official "frankly puzzled."' Klass's gesture in the direction of "prudence" is less than wholehearted, but one can quite see why he shrinks from endorsing this particular newspaper story when it calls in question the radio transcript against which he has found the second aircrew's debriefing account so wanting. The story is quoted to foment doubt about the Mooy memo, then irresolutely disowned, with Klass - appearing by sleight of hand to have his cake and eat it - conceeding that there are indeed doubts. An inadmissible line of questioning has been stricken from the court record, but its effect lingers in the minds of the jury.


pp. 116 para.2 to 117 para.1: Klass details his attempts to obtain information on any follow-up investigation that might have taken place, seeking contacts with "IIAF officials who might be willing to assist in my investigation." He writes to Colonel John Wilson, USAF, who had been in Iran at the time; Wilson can add nothing. He writes to IIAF vice-commander Azerbarzin (who had been Director of Operations at the time and present at the debriefing), telling him that he is sceptical of the report; Azerbarzin does not reply. He writes to the Iranian Ambassador in Washington, Ardeshi Zahedi, telling him that he is sceptical; Zahedi never replies. A letter to an Iranian science writer is returned "seemingly unopened". He writes to a professor of astronomy at Tehran University who had been quoted in a Tehran Journal article about the affair, telling him that he thought there was a "prosaic explanation"; the professor does not reply. He writes to a McDonnell Douglas technical representative in Tehran, but receives no reply. A letter to a Tehran executive of E-Systems Inc. is answered; but the "brief" response says that the writer can add nothing.


Comment: Klass becomes suspicious that this reticence is significant, and later (p.120 paras. 2 & 3) develops a conspiracy theory. The IIAF, he observes, was the multi-billion-dollar pride and joy of the Shah, and if (as Klass proposes) shoddy maintenance was leading to electronic glitches whilst aircrew training was so poor that pilots were "rattled" by bright stars and radar operators didn't know how to use their equipment, then "this would have been very embarrassing to IIAF officials - and to the Shah if it became public knowledge. This might also explain why USAF officials had not paid undue attention to the incident." To save embarrassment, suggests Klass, the authorities played up the UFO angle and made sure that the real problem was kept quiet.


   Earlier, Klass has argued that if Iranian or (more particularly) US authorities had taken the "UFO" incident seriously there would have been a widespread clamp-down on information; this didn't happen, therefore the authorities did not take the "UFO" incident seriously. Now he is suggesting that there was indeed a widespread clamp-down on information, but this does not lead him to re-evaluate the logic of his own argument. Instead it is further evidence that the "UFO" incident was not taken seriously.


p. 117 paras. 2 & 3: Ambassador Zahedi was pictured in the National Enquirer smilingly accepting a cheque for charity worth $5000 on behalf of the F-4 crews, selected by a panel of scientists as prizewinners for "the most scientifically valuable UFO case" of the year. The paper also stated: "Earlier this year Lieutenant General Abdullah Azarbarzin . . . told the Enquirer that virtually all communications, navigation and weapons control systems aboard the two Phantom jets were jammed by the UFO."


Comment: According to this newspaper the IIAF vice-commander, more than a year after the event, was personally certifying that the report of electronic anomalies in both F-4s, as given in Mooy's contemporary record, was correct. Klass italicises these words, stopping short of accusing Azarbarzin of a falsehood but implying confabulation at a high level. "It would be far less embarrassing . . . . Instead of possible humiliation, the IIAF flight crews later would be honoured for the best UFO case of the year by America's largest-circulation newspaper." (p.120 para.3) The most one can say is that this is speculation.


p. 117 para.3: "[Remote interference with fire-control electronics would be of] obvious import . . . . Yet USAF officials on the scene, who should have been gravely concerned if they accepted the IIAF crew's account at face value, seemingly were oblivious to the matter."


Comment: Whether or not any USAF personnel in Tehran accepted the account at face value is irrelevant to the facts of the case. And recording the facts as reported within hours of the event and forwarding them to interested US authorities with a promise of updated information when available is not being "oblivious to the matter." It has already been pointed out that, on Klass's own hypothesis, if US authorities took the report at face value it would not have remained the responsibility of personnel at the local level but would have become the subject of a more secure intelligence operation. Further, we note again that USAF and company personnel on the scene were not "even allowed to get close to the [quarantined F-4 at Shahroki], let alone being asked to check it over" (p.118, para.2), which can be taken as meaning that they would have liked to, but that such unilateral local initiatives were prevented.


   Klass's conspiracy theory has by now become quite sweeping, implicating Ambassador Zahedi, Gen. Azarbarzin, a Tehran University professor, a science writer, Middle East reps. of McDonnell Douglas and E-Systems, IIAF personnel all the way from Shahroki maintenance workshops to the vice-commander - even  perhaps the Shah! - none of whom seem able or willing to help Klass in pursuit of his "prosaic explanation". He manages to contact Mooy by 'phone, but he only confirms that there was no further local action by USAF or IIAF personnel "that I am aware of", and certainly does not disclaim any part of the information in his original memorandum (p. 117 para.1). All of this is open to various interpretations. But if Klass is right in suspecting a cover-up, is the reason which commends itself to him the most plausible? His evidence comes from two anonymous employees of Westinghouse Electric (manufacturer of the F-4's radar) who had been in Tehran and Shahroki at the time:


p. 118 para.2 "The Westinghouse tech rep [at Shahroki] told me that only the second F-4 was briefly 'quarantined' when it returned to the base by being placed in a remote revetment . . . . This confirms that only the second F-4 experienced any seemingly mysterious UFO-induced effects."


Comment: This is speculation. What it confirms is that for whatever reason the second F-4 was quarantined in a remote revetment at Shahroki. His conclusion, that the report as written up by Mooy and endorsed by Aazarbarzin is false, is a non sequitur. However, having noted that no local US specialists were allowed near this F-4, Klass's interpretation of this proceeds by hearsay, ellipses and insinuations:


   The F-4 was "briefly" quarantined, then "less than a week later . . . returned to active duty, seemingly none the worse for its UFO encounter." IAAF maintenance crews, according to what Klass's Westinghouse informant was told, "'claimed that . . . the only thing they found wrong was that one of the radios had some static in it,'" which is "not an unusual complaint", adds Klass, implying that no unusual aftereffects of the UFO encounter can be brought as evidence. But then we have a change of tone, preparatory to the argument that poor maintenence must have caused the reported electronics outage, as well as the radar contact: the same tech rep was called in about a month later to adjust the plane's radar, which according to Klass implies that the radar might not have been working properly on September 19, causing a false target; also, it turned out that this F-4 allegedly had a history of power outages, so that it must have been quarantined in order to fix embarrassing glitches out of sight of foreign eyes. The suggestion is now that there was a great deal wrong with the F-4 when it flew back to Shahroki! This tells us more about Klass's journalistic technique than it tells us about the facts of the case - which here reduce increasingly to opinions quoted from Klass's anonymous Westinghouse informants whose own position in this affair is unknown. Indeed, reading carefully discloses that the story of the F-4's poor service history comes from an anonymous rep in Tehran who looked into events at Shahroki "as far as he could", and is in turn relating what he had heard from an anonymous McDonnell Douglas rep at Shahroki. Thus Klass's account is itself based on a story retold at second hand, whose ultimate source (a McDonnell Douglas employee) has by implication already been called in question - because when the McDonnell Douglas rep in Tehran had failed even to answer Klass's letter about the incident this was one of the many "frustrating" rebuffs which caused Klass to suspect a cover-up! Indeed, what would these manufacturers' reps' vested interest be here when approached by a senior editor of Aviation Week & Space Technology with a predatory eye to exposing faulty avionics in their products? It would be to disarm any suspicion of design or manufacturing defects by passing the buck to IIAF maintenance technicians with stories about probable sloppy workmanship and  inept aircrews. This is exactly what Klass's informants do: he quotes yet another anonymous company source to the effect that the IIAF was no more than a "flying country club for the sons of rich families"; the Shahroki electrical shop was "notorious for poor performance" offers another; pilots had almost no training at all in night flying; radar operators were "not too knowledgeable", were "not really trained" to use the radar or fire-control instrumentation and only wanted to "move into the front seat", argues a Westinghouse rep; and so on. And all this in the Shah's "pride and joy"! It seems a wonder that the IAAF were ever able to get two planes into the air in the first place.


p. 119 para.4: "One thing is evident: the second F-4 crew was clearly 'rattled'. This is obvious from their report that the target on their radar scope was at a range of twenty-five miles, but they were preparing to fire an AIM-9 air-air missile whose maximum range is only a couple of miles. . . . Thus their missile could not possibly have reached the 'target-blip' appearing on their radar."


Comment: Mooy's debriefing record clearly states that the primary target was at 25 miles when "another brightly lighted object . . . came out of the original object. This object headed straight toward the F-4 at a very fast rate. The pilot attempted to fire an AIM-9 missile at the object . . . ." [Emphases added] Klass's confusion stems from his interpretation of a story published in the Tehran Journal which is too vague and compressed to be relied upon even if it did clearly contradict the debriefing - which it does not. This third-person narrative is based on translation of the Persian-language newspaper account of the taped radio communications and reads as follows: "[The] pilot reported having seen the UFO and told the control tower that it had reduced speed. The pilot said the plane was working well and he was preparing to fire missiles at the UFO. After a moment's silence he said he had seen a 'bright round object, with a circumference of about 4.5 meters, leave the UFO.' A few seconds later the bright object rejoined the mother craft and it flew away at many times the speed of sound." Klass concludes that "preparing to fire missiles" means that the pilot was at that instant about to push the button and engage the object at a range of 25 miles; but, even allowing that this phrase is a precise quotation of the pilot's words (for which there is no justification), "preparing" in this context is no more than a declaration of intent to open fire - which would suggest reasonable caution and may even have been required by the IIAF rules of engagement. When the secondary object unexpectedly headed straight towards his aircraft and the pilot did decide to launch a missile at it, he would have been unable to do so had he and his weapons-control panel not both been primed - i.e., "prepared".


p. 119 para.4: "Later I would be told that this second F-4 crew had been awakened out of a sound sleep and dispatched on the UFO mission, so it is entirely possible that their judgements may have been clouded by not being fully awake."


Comment: This is pure nonsense. No doubt if the crew had been wide awake for hours at the time of their 0140 scramble Klass would have argued that they must have been fatigued after a long day and ready to nod off!


   And now (p.120 para.5 et seq.) we see why Klass has persisted in his quaint description of the secondary object reportedly emitted as a "rocket-missile" and a "missile-like object", although the report describes a highly manoeuvrable  object which "fell in trail" with the F-4 at a distance of 3-4 miles as the pilot executed an evasive turn and dive, then "went to the inside of his turn" and headed back to the primary object "for a perfect rejoin." The phrase "missiles or rockets" is one used by an Eastern Airlines captain over Virginia in 1975 to describe what, according to the FAA, were "probably" fireball fragments, and Klass now quotes this case in illustration of the fact that pilots can sometimes report bright meteors as UFOs.


p. 121 para. 4 et seq.: "Is it possible that the missile-like objects reported by both of the Iranian F-4 pilots, and the glowing objects reported by ground observers near Tehran to have fallen from the sky or flitted across the sky, might have been meteor fireballs?" Klass then embarks on a discussion of other sightings from Morocco and Lisbon on the same night as the Tehran event that he takes to have been probably one-and-the-same fireball meteor.


Comment: This is pureed red-herring as, eventually, Klass admits, because these reports "would not coincide with the timing of the missile-like objects reported by the two Iranian F-4 pilots, which would have occurred several hours earlier." Furthermore both Lisbon and Morocco are some 3,500 miles west of Tehran! Once again, the "missile-like" image is reinforced to help the reader follow his argument. He notes that an abnormal number of "fireball" sightings that night would be expected because there were two meteor showers underway at the time. Aside from the fact that there is a meteor radiant in any observer's sky on any night of the year (see B.A.A. Handbook, 1922), and neither the September Aquarids nor the Southern Piscids are major North Hemisphere showers, the reported fireball trajectories were W-E according to Klass; but the two object reported as "buzzing" the F-4s from ahead and behind (allowing that their trajectories would have been in part straight) would have been heading approximately N-S and S-N. The first F-4 was heading N when, according to Klass, the object passed him from behind (although, as has been argued, the aircraft at this point appears to have already turned back for Shahroki, which would suggest a heading N-S); and the second F-4 was pursuing the object on "a course to south" when a secondary object headed "straight" for him. Klass describes an "object coming at him [the first F-4] from behind (from the west) that passed overhead", although there is no justification for these details in the report. The pilot only described an object "coming from behind [his a/c or the UFO]", and indeed the phrase "level with me now" implies the object flanking him if anything, and certainly does not imply that it passed "overhead". Klass wants to paint a picture that fits with his meteor theory, including inventing the E instant heading of the F-4, because the (possible) meteor sightings were of objects travelling W-E. In fact he even fudges this: the Moroccan "fireball", he says, was reported ". . . coming out of the W or SW on a NE heading similar to the [W-E] trajectory reported [from Portugal]." The Moroccan reports describe a heading either NE or north of NE, generally paralleling the Moroccan Atlantic coast; Klass inserts the "west or southwest" for effect.


   Finally, the identification of the earlier Morocco-Portugal reports as meteor sightings is less than certain since consistent reports from numerous areas stretching in a rough line along the western Moroccan coastal zone, from Agadir in the south to Fez in the north, spanned about one hour. A typical sighting was made by a Moroccan official who personally briefed the US Defense Attache: he saw it from near Kenitra at 0115 local, travelling low and parallel to the coast at a very slow speed like that of an aircraft preparing to land. When distant it appeared to be disc-shaped, but when it passed closer to his position he could see it as a luminous tubular object. In reply to a request for assistance sent by the American Embassy in Rabat, Secretary of State Henry Kissinger stated that no U.S. aircraft were in the area, there was no record of any satellite re-entry and there were no prominent meteor showers, but speculated that the object may have been a sporadic fireball meteor on a rare tangential trajectory or an unlisted satellite re-entry. (Messages 250801Z Sep. 76 and 052041Z Oct. 76) However, if the reported times are correct these theories are untenable: sightings in Morocco occurred between 0100 and 0200; the object was reported from Portugal (in the same time zone and N of morocco) just after 0210. Klass speculates that Portugal may have been using Daylight Saving Time whereas Morocco was not, which would place the Lisbon sighting at 0110 Morocco time, although he was "not able to resolve" this; but even if this were true it would not remove the 60 minute difference between first and last sightings in Morocco. (In terms of trajectories the Portuguese incident could have involved the same object. This one reportedly passed W-E. It was sighted by an aircrew bound from Lisbon to Africa and thus on a heading roughly S, and appeared to pass by within a few hundred yards of their aircraft, so that an object following the Moroccan coast NE could have crossed the nose of an aircraft flying south from Lisbon. This geometry would hold true either for a simultaneously-sighted fireball at (say) one or two hundred miles from the Moroccan coast, or for a slow-flying object in local airspace which was independently sighted later.) It is possible that most of the Moroccan times are in error and that a fireball was seen, but the case is far from proven on the available evidence and, in summary, these incidents are of extremely tenuous relevance to the events over Iran several hours earlier and 3,500 miles away.


p. 122 para.3: "[The F-4 crews] would be under considerable stress [and] if they saw meteor fireballs zipping across the sky, they could, quite understandably, conclude that these were rockets or missiles which the unknown object was firing at them."


Comment: That crew "stress" was "considerable" is as suppositious as the "soundness" of the sleep out of which Klass says they were woken. Moreover, the "firing" of "rockets" once again is a distortion of the facts as reported.


p. 122 para.4: "Under such stressful conditions, even experienced flight crews become unreliable observers . . . . The second F-4 crew admitted that they were experiencing "some difficulty in adjusting their night visibility", according to Mooy's report, and they had difficulty attempting a landing at Mehrabad Airport, despite its modern lighting-landing aids."


Comment: The crew did not "admit" anything; they stated that their night vision had been affected. Klass is again attempting to erode witness competence by baseless insinuation. It is perfectly clear from Mooy's report that the problems with night vision occurred after the event and as a direct result of the brilliance of the object(s) (as the DIA evaluation notes) not from some pre-existing "stress". This misrepresentation is carried over into the landing episode, the reader being encouraged to believe that the crew were so "stressed" that they could hardly fly the plane, or even see the airfield! Mooy's report again makes clear that they orbited Mehrabad a few times to allow their night vision to recover, then "went out for a straight-in landing." This seems perfectly sensible.  Doubtless Klass would diagnose unreasoning panic if they had landed without waiting for their eyes to become properly dark-adapted.


p. 123 para.1: "It might seem difficult to accept the idea that the F4's power system chanced to malfunction when the aircraft 'passed through a Mag bearing of 150 degrees from Mehrabad', as the crew reported . . . . But it seems to me equally unlikely that a UFO would decide to 'zap' the F-4 only when it was on one specific bearing relative to the airport. The F-4 crew report that an airliner approaching Mehrabad at the same time experienced a communications failure seems mysteriously related to the F-4 problems. But whereas the F-4 experienced malfunctions in many of its avionic systems - indicating electric-power-system problems - the airliner seemingly experienced trouble only with one piece of radio equipment."


Comment: It would be more "difficult" to accept Klass's proposal if he pointed out that the same failure happened "each" time on "several" orbits of the F-4. Clearly it is not the bearing from Mehrabad that is significant here but the location as defined by the intersection of that bearing and the orbital track of the F-4. This location is presumably where the airliner radio failure occurred - "in same vicinity (Kilo Zulu)". Klass also states without justification that the F4 crew reported this airliner's radio failure - presumably with the "stress" and "poor training" of the F-4 crew in mind. The debriefing contains no such suggestion. It seems unlikely that the F-4 crew would be the source of intelligence about events on board a civil aircraft with which they would have had no contact, and much more likely that this information, like other background supplied in the memorandum, came to Mooy via his other IIAF sources from Mehrabad control tower and/or the civil aircrew. Klass suggests that the F-4 experienced strikingly different effects from those reported by the airliner. But only the F-4's UHF radio failed in this vicinity, with some "fluctuation" in the inertial navigation system; not as Klass describes it "malfunctions in many of its avionic systems indicating electric-power-system problems". Why such phenomena, if related to the "UFO", should have happened is unknown, but plainly Klass's straw-man hypothesis that the "UFO decided to 'zap' the F-4" is irrelevant and anthropomorphic science-fiction.


p. 132. para.2: Klass passes on a suggestion offered by Mooy to explain the "beeping signal" detected by the searching helicopter next day in an area off to the west of the spot where the F-4 crew thought the bright light emitted by the primary "UFO" had landed. Mooy observes that some large transport aircraft in service in the area carried emergency crash-locator beacons which transmitted a similar type of signal, and these had been known to eject occasionally during flight as a result of "severe turbulence". Moreover turbulence was often "experienced over the mountains near Tehran."


Comment: This is an interesting hypothesis, although some points need to be qualified. If it is logical that the UHF failure (which reportedly had occurred before when the F-4 approached within some 25 miles of the object in the air) was related to the location of the object whose position on the ground had been "observed and marked" by the aircrew before they came in to land, then it would follow that the bearing from Mehrabad of this landing location was 150 degrees magnetic. This would be SW of Tehran, not inconsistent with the fact that the F-4 had been pursuing the primary object "on a course to the south of  Tehran" when it emitted the bright object which appeared to land. The "mountains near Tehran" which would be responsible for severe turbulence, however, are concentrated in the Alborz Range to the N and NW; whereas a bearing SW from Tehran indicates lower terrain in the direction of the Dasht-e Kavir salt pans some 50 miles from Mehrabad. This conjecture is supported by the description of the "landing" site as a "dry lake bed", and the topography would thus not be consistent with the severe mountain turbulence which, ex hypothesi, might prematurely eject a crash-locator beacon.


   It is true to say, however, that this incident has no direct relationship with the events of the previous night, and none is being claimed. If the search helicopter did randomly pick up a radio beacon this is not evidence of anything except the finding of a radio beacon. It should be noted that the "beacon" signal was not in fact detected at the site marked as the landing point by the F-4 crew. There, "nothing was noticed", and it was when the helicopter circled "off to the west of the area" that the signal was first picked up and followed to the point at which it was strongest. The only part that this signal appears to have played in the affair - whatever it may have been; and a crash locator beacon remains a clear possibility - is that it fortuitously led the helicopter to a "small house with a garden" whose occupants, when questioned, confirmed that they too, like many other in the Tehran area, had seen a "bright light" and heard a loud noise during the night.


p. 123 para.3: Klass suggests that the primary object reported by both F-4 crews and the objects sighted from the ground might have been "a celestial object, perhaps the bright planet Jupiter. Certainly the second flight crew's description sounds like many other UFO reports, where the object proved to be a bright celestial body, and this would explain the F-4's inability to 'close' on the object.""


Comment: Klass has long since ceased to address the F-4's reported radar lock-on during this "inability to 'close'" - indeed, he never addresses the radar target(s) at all, save to imply that the operator was probably confused and inept. Considered simply as a visual report there is some similarity to (say) a bright planet viewed along an inversion layer with consequently extreme scintillation, and it is true that Brigadier General Yousefi described an object which, from the ground, appeared "similar to a star but bigger and brighter".. But consider the different bearings involved: a Mehrabad tower controller told the Tehran Journal that at one point the object was over the south of Tehran, that is, on a bearing SW from the airport; yet the first F-4 pursued the object on a heading due N, looking "so bright it was easily visible from 70 miles" and "half the size of the moon . . . radiating violet, orange and white light about three times as strong as moonlight." If this was Jupiter, then what was the object which the second F-4 pursued on "a course to the south of Tehran", exhibiting "intense brilliance" with a pattern of strobing coloured lights? Note also the localisation of the initial civilian reports "in the Shemiran area", which is suggestive of something in local airspace rather than something celestial.


p. 123 para.4: "If the prosaic explanation seems strained, consider the alternative: that the 'UFO' was an extraterrestrial spaceship with the remarkable ability to selectively disable many avionic systems on the F-4, only the radio equipment on an airliner, without causing any interference in any IIAF air-defense radars or the Mehrabad radio equipment. Despite this remarkable defensive capability, the 'UFO'  decided to fire an 'old-fashioned' rocket-missile at the second F-4, which missed the airplane and landed on a dry lake bed without causing an explosion. And the next morning this rocket-missile mysteriously disappeared, leaving behind only a mysterious beeping radio signal, similar to that emitted by crash locator beacons."


Comment: Klass can see no alternative to his own scenario, other than "an extraterrestrial spaceship", which in another author might betray a certain poverty of imagination. But Klass is not so ingenuous, and in this concluding paragraph is erecting his last row of straw men: 1) The "spaceship" is at best an irrelevance; 2) what was previously a mundane set of faults attributable to an "electric-power-system-outage" is now mysteriously "selective"; 3) there is no information in any available report about what may or may not have occurred at any air-defense radar sites concurrent with the brief periods of avionics failure; 4) if there was no "interference" noted at any such sites, the relevance of this fact to avionics failures in three aircraft near Mehrabad would be at best unclear; 5) whether Mehrabad UHF radio reception suffered any concurrent "interference" is difficult to know when the only aircraft with which communication could have occurred (the F-4 and "the one civil airliner" in the area) suffered radio failure; 6) why any possible "interference" with Mehrabad UHF equipment should be a necessary condition of avionics failures occurring in these aircraft is unclear; 7) the "remarkable defensive capability" of the object and its ability to "decide" actions are pieces of anthropomorphic science-fiction; 8) "an 'old-fashioned' rocket-missile" is more science-fiction, and even the image which Klass intends to convey has no basis in the reported facts; 9) the complaint that the secondary object "missed" the aircraft assumes without justification that it was intended to "hit" it; 10) since the "rocket-missile" is imaginary there is no reason to expect any "explosion" on the dry lake bed; 11) it is untrue that "this rocket-missile mysteriously disappeared", since there is no evidence that such a device existed in the first place; 12) the "mysterious beeping radio signal" traced to a spot some distance from the site many hours later may well have been unconnected with the incident, and if this is indeed the case then nothing whatsoever is to be inferred from it.


Summary: Many of Klass's arguments are logically flawed, a number of "facts" adduced as evidence are found to be speculation and hearsay, and the overall framework of his scenario is in some important respects internally inconsistent. Most significantly, he fails to address the core quantitative details of the original radar-visual report in any way. In conclusion, Klass's analysis fails to clarify our understanding of the case.


STATUS: Unknown


The End