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The RB-47 pursuit is actually two segments. The first eight minutes involves the aircraft’s beeline approach towards Fort Worth and Dallas towards the UFO. This was followed by a 360 degree turn and departure of the plane from the area.
Eight minutes to Dallas
At 1042Z, the RB-47 turned to the northwest to pursue the UFO the saw in the direction of Dallas-Fort Worth. In Chase’s UFO report, he states he took a bearing of 320 degrees true (Note: This is the only time that Sparks accepts the heading written by Chase in his report as being a true heading and not magnetic!). The path to Dallas was made at maximum speed according to Chase. Both reports (Chase and Piwetz) state they accelerated to Mach 0.83 at 1042Z and took up pursuit.
However, after looking at the flight path with Klass, Chase stated:
I don’t think Mach .83 can be write (sic) for an extended period of time – as I went to maximum allowable mach – mach .87-.92 sounds more like it.1
Chase was speaking from memory but we know from the aircraft’s specifications the maximum speed listed for the plane is actually Mach 0.85 and that speeds above that could cause a high speed stall. So, it seems that this value was something of an exaggeration on Chase’s part.
The air crew estimated the UFO/light was 10 nautical miles northwest of Fort Worth. This was apparently confirmed by Duncanville’s radar (although no altitude was given for the object they tracked). In his early discussions and his report in 1957, Chase seemed to agree with this position for the aircraft at time 1050Z. Brad Sparks would use this position as his endpoint for the flight to the northwest.
At time 1050Z, as the plane approached the light, it disappeared, McClure lost the signal he was tracking, Duncanville lost its target, and the navigator supposedly lost his radar contact with the UFO. The UFO had simply vanished from all sensors as if it were never there.
Pilot Chase describes what happened at 1050Z in his interview with Dr. McDonald:
….He stated that, as far as his impressions
as the pilot was concerned, all of the closure motion was due to his own flight speed, as if the Unknown were then stationary.
2
While Chase may have felt the light was stationary, one could also conclude that the light may have been moving towards or away from the aircraft at a much slower
speed.
He also described that he did not meet the light “head-on”.
I asked him the way in which he flew over the object. It became clear that he did not pass directly over it, but flew to the right of it. He said it was almost below them, nearly 90 degrees below the horizon when it blinked out .3
Dr. McDonald thought he flew to the right but what Chase told Klass was:
...I understand why you wouldn’t understand me keeping the object off to my right. I turned right to an intercept angle, but even as I closed on it, in its apparent hovering, I kept it right.4
Perhaps McDonald was confused in his notes about what was right and what was left. In either case, Chase seemed to indicate the object was apparently stationary
and he passed with the light off to one side.
One item I noticed when flying the B-47 in Flight Simulator X was that the pilot can not see directly below the aircraft. The cockpit does not allow for a good view unless the pilot banks the plane. Chase told Klass that it disappeared before it became invisible from his point of view. Flying straight and level in Flight Simulator X gave the impression
to me that the pilot could not see objects below him about 3 miles in front of the aircraft (at an altitude of 34,500 feet). I am not sure if this was the case for a real pilot in the aircraft but if it were, that means that at a depression angle of about 70 degrees, things become difficult for the pilot to see from his position in the cockpit. If the UFO were 5000 feet below him at this point, this would mean the closest the UFO was before they overshot it, was less than a mile away. Despite this proximity,
the UFO still was just a bright light and nothing more.
Radar contact???
In addition to the ECM#2 operator receiving radar signals, Sparks states the navigator was close enough for a radar contact:
The first UFO overshoot is evidently the time when the RB-47 navigator, Maj. Thomas Hanley, briefly detected the UFO on his aircraft navigation radar, APS-23, after apparently spending quite some time attempting to do so.5
This part of the incident seems more fiction than fact. His conclusion is based on two bits of information. One was the testimony of McClure, who states that Hanley tracked the UFO with his radar and the other is the comment in the CIRVIS report that states the B-47 tracked the UFO.
However, this seems unlikely because Hanley told McDonald that he never tracked the UFO.
He said that he had search radar on and was looking all around and in every way he could, but never had any radar contact with the object.6
McDonald stated he could not confirm one way or the other by the Copilot, McCoid:
…He could not recall whether the navigator got any radar return on his set.7
Chase’s actual report, written in 1957, states they were unsuccessful on tracking it with the plane’s airborne radar (although he did mention scope photographs were taken, which was denied by Hanley). Chase may have been referring to the ground radar and the CIRVIS report probably reflects the crews reception of the radar signals and not an actual tracking with the navigation radar. All of this seems to indicate there never was any tracking of the UFO with the airplane’s radar.
1050Z is where???
At this point, it is important to discuss the flight path and where the RB-47 may have actually been at time 1050Z. One can not accurately determine where the RB-47 was without the Navigator’s log, but we can make some assumptions and determine the possible position.
We do know the capabilities of the aircraft though from the flight envelope chart and manual. Since the plane could only travel at Mach 0.85 at maximum (about 9.7 miles/min at 34,500 feet), the plane could only displace about 68 miles in the seven minutes after the turn towards 320 degrees (which, according to Sparks took a full minute).
In my computed path (which is an approximation), the 1050Z mark occurs very close (about 2.5 miles SSW) to the Duncanville radar (approx 96-54.5/32-39).
When discussing the flight path with Klass, Chase recognized problems with the speed and distance. He would eventually make the following statement:
We were just barely south of Fort Worth-Dallas, or just abeam, when the object disappeared.1050 was the time the object disappeared.8
If this position is correct, it explains why the radar signal disappeared for McClure. Although Klass felt the signal would disappear farther out, Rod Simons felt that the sensors might be possible to detect the Vertical center beam right up to the antenna. The disappearance may have occurred due to the signal being too weak or the beam of the radar being below the antenna’s depression angle. It is hard to ignore the proximity of the plane to the Duncanville radar site when contemplating why the signal was lost
Round and round we go
After overflying the UFO, Chase began looking for it again. The natural thing to do would be to bank the plane and attempt to make another pass. In this case, he began a turn to port. In his interview with Klass, Chase stated he was told by McClure that he had a bearing on the UFO and he looked in that direction and saw a light. He then maneuvered the aircraft in a big circle in order to intercept the UFO. Exactly when his turn to port began is hard to say but one can reasonably assume that it was between 1050 and 1052Z.
In the Piwetz account, at time 1052Z Chase saw a light/UFO, which forced him into a turn. We are not even sure that this UFO/light was the same one he had overflown.
All we know is that he saw a light that he estimated was at 15,000 feet. This is where he states he made a dive at the UFO. As he closed within 5 NM, the UFO/light simply disappeared. There was no evasive maneuver, no rapid acceleration, and no craft visible. It simply winked out.
At this point, the plane continued to fly in a circle, looking for the UFO again. The exact position of this circle is not that clear. We know it happened around the city of Fort Worth but exactly where is hard to say. The Piwetz report describes the plane being near Mineral Wells at 1055Z, which pilot Chase told Klass was not possible.
It is clear that Piwetz was trying to be accurate but the air crew just did not get some of the details correct or he misinterpreted what they told him.
At 1055Z, it was realized the plane had used a great deal of fuel and needed to return to base. The RB-47 continued flying in a circle and at 1058, they once again saw the UFO at 20,000 feet some 20 NM northwest of Fort Worth. It is not clear if Duncanville had any contact with this UFO because at time 1057, they stated they had no contacts.
The report is quite confusing at this point and Piwetz made some mistakes in interpreting what the crew told him on several occasions. Chase mentioned some of this in his discussion with Klass:
I’m sure the confusion in the intelligence report is misunderstanding of times for the object and times for the aircraft...What a shame we weren’t shown the intelligence report then...9
Klass seems to think the final position of the light may have been an error and the actual position was southwest and not northwest of Fort worth. Chase never mentioned any visual sighting of a UFO after the second one, which he dove upon. Could it be that Piwetz just misinterpreted
what the crew stated and was simply repeating the account concerning the initial approach to Fort Worth-Dallas? It seems plausible this was the case.
RB-47s are not dive bombers
One part of the Chase account seems to be inaccurate. According to him he was flying the RB-47 at high speed and then dove on the UFO by dropping 15,000-20,000 feet in a minute or so. Could the RB-47 accomplish such a maneuver?
It seems highly unlikely that the plane would (or could) be put in a steep dive over a short distance from 34,5000 feet to 15,000-20,000 feet. The B-47 operations manual states:
2-47 The extreme cleanness of this airplane and the fact that it is operating near the buffeting range in level flight limit it to very shallow dive that must be executed with extreme care. As with all high speed operation, abrupt accelerations must be avoided.10
This seems to be within the guidelines outlined in the B-47 operations manual, which describes the descent procedure as follows:
Maintain cruising altitude until about 45 nautical miles from landing point....Descend at the maximum rate but do not exceed Mach 0.82 and/or 304 knots IAS.11
This indicates that the maximum descent angle would be less than 10 degrees. Col. Walter Boyne states on his blog that the plane descended for landing at high speeds using a rate of 6000 feet per minute. All of this indicates the plane descended at an angle of less than 10 degrees. For a plane to descend roughly 15,000 feet in about 10 miles, the angle of attack would have been something like 17 degrees so it appears that Chase’s description of this event may not be quite accurate.
McClure was of the opinion that this dive never happened.
I DON”T REMEMBER NO PART OF THIS DIVING BUSINESS AND I DON”T BELIEVE IT HAPPENED...12
Dr. McDonald’s interview notes with the copilot McCoid also indicated this maneuver probably did not happen as described:
He did not recall overflying the Unknown, nor did he recall the bank or dive near Mineral Wells.13
McClure was in the capsule and probably could only tell if there was a dive if the plane’s angle of attack changed drastically.
This would be the case if it was a sharp dive towards 15,000 feet. So, any change in altitude, must have occurred over a much larger distance than a quick change in altitude as claimed.
This brings us into several possibilities.
We do know the plane eventually reached around 20,000 feet but how did it get there? I think there are some possibilities that might explain the change in altitude without a dive-bombing attack on the UFO as described by Chase.
2000 feet per minute Is it possible that the RB-47 actually began descending after the turn at 1042-43Z? Chase made the following statement to Dr. McDonald regarding the start of the pursuit at time 1042Z:
He had to contact FAA to get a clearance to change his flight path at this point. They cleared all the traffic out of there, and gave him an OK on it.14
However, he stated almost the same exact thing to Dr. Roy Craig regarding the events near Mineral Wells:
So, as I came around, about half way around the turn, we picked him up with lights on again. Only now down at a lower altitude. I told GCI that I estimate him to be at about 14,000 feet. I said I’d like to go down on him and they said, “Roger. We have the traffic in the Fort Worth area cleared out. It’s clear to go down.”15
So, it might be possible that the plane actually began descending at 1042Z towards 15,000 feet. If Chase continued flying at the maximum possible speed, the lower altitude would allow higher air speeds. By my calculations, it would extend the 1050Z point about two miles to the northwest.
In that scenario, it is possible the plane descended to 15,000 feet at a rate of about 2,000 feet per minute. I doubt this scenario is likely and suspect there is a more likely sequence of events. 5000 feet per minute Another possibility is the plane began diving towards 15,000 feet over a three-four minute period starting just before time 1052Z. I think this is a more likely possibility. In that scenario, the plane would have descended at a rate of about 5,000-6,000 feet per minute, which is consistent with what Colonel Boyne wrote about the B-47 landing rate. The angle of attack in that case would have been something like five degrees, which may have not been that noticeable to McClure in the ECM pod. I would incorporate this scenario in my flight path in the circle around Fort Worth:
Some notes about this path are that the plane was flying at Mach 0.85 initially and continued on its 320 bearing for one full minute after that before beginning the turn. Initially, the turn was calculated at 30 deg/min and I increased it to 40 deg/min at time 1056-59 as the plane began to slow down. The planes departure speed was Mach 0.74 (539 mph) on a bearing of 20 degrees.
The Departure
At 1102Z , with the RB-47 running low on fuel, Chase turned the plane towards Forbes AFB near Topeka, Kansas and exited the area. Nobody knows what happened to the UFO and nobody seemed to care at this point. No fighters were sent up to investigate that morning even though there were plenty of sources for such aircraft in the area.
According to the Piwetz report, they were able to observe the radar signal from the UFO all the way up into Oklahoma when they were near Oklahoma City. These radar
signals were at a bearing of 180-190 degrees.
There is one point of contention in this final portion of the report. The report states the plane was abeam of OKC at time 1140Z. The distance from Dallas to Oklahoma City is only about 190 miles. Does this mean the plane was operating at speeds of about 300 mph (260 knots), where the plane’s fuel efficiency was low (see the graph and comment from the B-47 manual on page 7)? In Klass’ original plot, he assumed this must have been an error in the 1102Z comment and that it really was supposed to read 1120Z. That would mean the RB-47 was loitering around looking for the UFO for 20 minutes after descent to 20,000 feet. One can’t be sure and it seems unlikely that the plane would have slowed down to a speed that was not efficient to conserve fuel. It is more likely that this time of 1140Z was in error and it probably was more like 1120Z.
Radar signal analysis
There are several bearings to radar signals given in the Piwetz account that should be discussed at this point.
For the 1042.5 signals, the RB-47 was about halfway into its turn from 260 to 320 giving a true heading of about 280-300 degrees. This gives us a true bearing of these two contacts of 320-340 and 350-010. The true bearing towards Duncanville was about 322 degrees and the bearing towards OKC was about 345 degrees. Like the previous two signal observations at time 1040, the report only notes that the operator recorded two signals at these bearings. They did not have to be the exact same frequency. Considering
the margins for error, this appears to be a possible match.
At time 1044Z, the plane was on a heading of 320 degrees, which makes this signal interesting. The bearing of the signal would be at 10 degrees true, which is too far to the right to have been the OKC or Duncanville radar beams. However, at a true bearing of about 2 degrees is that pesky Bartlesville, OK FPS-10 and 4.5 degrees for the Tulsa WSR-1. Bartlesville was still was about 330 miles away (beyond the normal radar horizon) but Tulsa was closer at 290 miles (approx). Once again, it is important to note there were conditions in the atmosphere that might have extended the distance at which these signal could be detected. Other potential suspects would include unknown S-band ground or an airborne radars.
We do know that McClure was following one radar signal throughout this part of the pursuit because he notes that the signal was lost at time 1050Z. Klass points out that if he were focusing on the center beam of the Duncanville radar and the plane passed close to the radar, this signal would simply “disappear”.
After leaving the area close to the radar, the signal would reappear towards the rear of the aircraft exactly as described at times 1051 and 1052. A turn towards the west would cause the signal to move towards the port side and go “up scope”. The plane continued its turn to port and, based on my computed flight path, the plane was about 24 miles SSW of Fort Worth at time 1057Z. From this position, the Duncanville radar station was at a true azimuth of 60 degrees. With a heading of about 120 degrees, the resultant relative bearing would have been the same 300 degrees in the Piwetz report.
After 1102Z, the plane began its return to Forbes AFB in Kansas. The signal now appeared behind the plane in the direction of the Duncanville radar and disappeared when they approached OKlahoma City (about 190 miles away). At this moment, the plane was at 22,000 feet, which is below the optical line of sight for the lower sidelobe of the Vertical Center beam and probably beyond that sidelobe’s radio horizon. However, they were not below the radar horizon for the radar’s other beams. The coincidence of the detected beams direction being towards Duncanville indicates it is plausible that this was the source of the signal.
Except for the 1044Z signal, there seems to be reasonable explanations for all the other values. It is even possible that the 1044Z signal is explainable. One can reasonably suggest that the radar signals during the pursuit phase really were not very mysterious and the only thing strange about this part of the incident were the lights that vanished when the RB-47 came near them.
Notes and References
Undated letter from Lewis Chase to Phil Klass 1. with comments on 2 October 1971 letter from Phil Klass. American Philosophical Society. Philip Klass Collection. Box Series II-6.
McDonald, James. 2. Interview notes with Lewis Chase. January 30, 1969.
McDonald, James. 3. Interview notes with Lewis Chase. February 1, 1969.
Letter from Lewis Chase to Phil Klass dated 27 4. October 1971. American Philosophical Society.
Philip Klass Collection. Box Series II-6.
Sparks, Brad. “RB-47 radar/visual case”. 5. The UFO Encyclopedia: The Phenomenon From The Beginning, Vol. II: L-Z, 2nd Edition. Jerome Clark editor. Detroit, MI: Omnigraphics, Inc.; 1998. Page 784
McDonald, James. 6. Interview notes with Thomas
Hanley. February 1, 1969.
McDonald, James. 7. Interview notes with James McCoid. February 2, 1969.
Undated letter from Lewis Chase to Phil Klass 8. with comments on 2 October 1971 letter from Phil Klass. American Philosophical Society. Philip Klass Collection. Box Series II-6.
Ibid.9.
USAF. 10. B-47A Flight operating instructions handbook. Secretary of the Air Force and the Chief of the Bureau of Aeronautics. 1 July 1950 updated 30 October 1950. P. 42.
Ibid. P. 4311.
Klass, Phil. 12. Interview notes with Frank McClure. 22 September 1971. American Philosophical Society. Philip Klass Collection. Box Series II-6.
McDonald, James. 13. Interview notes with James McCoid. February 2, 1969.
McDonald, James. 14. Interview notes with Lewis Chase. February 1, 1969.
Craig, Roy. 15. UFOs: An Insider’s View of the Official
Quest for Evidence. Denton: University of North Texas Press, 1995. P. 140
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Quelle: SUNlite 1/2012
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