On July 17, 1957, an Air Force RB-47, equipped with ECM gear (electronic countermeasures)
was followed by an UFO for over 700 miles
As the aircraft crossed the Mississippi coast near Gulfport, McClure, manning the #2 monitor, detected a signal
near their 5 o'clock position
(aft of the starboard beam).
It looked to him like a legitimate ground-radar signal, but corresponded to a position out in the Gulf
This is the actual beginning of the complete incident.
What was RB-47 equipped with.
Under conditions of war, bombing aircraft entering hostile territory can be assisted in their penetrations if any of a variety of electronic
countermeasures (ECM techniques as they are collectively termed) are brought into action against ground-based enemy radar units. The initial step in
all ECM operations is, necessarily, that of detecting
the enemy radar and quantitatively identifying a number of relevant features of the radar system (carrier frequency, pulse repetition frequency,
scan rate, pulse width) and, above all, its bearing relative to the aircraft heading. The latter task is particularly ample in principle, calling
only for direction-finding antennas which pick up the enemy signal and display on a monitor scope inside the reconnaissance aircraft a blip or lobe
that paints in the relative bearing from which the signal is coming.
The ECM gear used in RB-47's in 1957 is not now classified; the #2 monitor that McClure was on, he and the others pointed out, involved an ALA-6
direction-finder with back-to-back antennas in a housing on the undersurface of the RB-47 near the rear, spun at either 150 or 300 rpm as it scanned
in azimuth. Inside the aircraft, its signals were processed in an APR-9 radar receiver and an ALA-5 pulse analyzer. All later references to the #2
monitor imply that system. The #1 monitor employed an APD-4 direction finding system, with a pair of antennas permanently mounted on either wing tip.
Provenzano was on the #1 monitor. Tuchscherer was on the #3 monitor, whose specifications I did not ascertain because I could find no indication that
it was involved in the observations.
As the lobe continued moving upscope, McClure said the strength of the incoming signal and its pulse characteristics all tended to confirm that this
was some ground unit being painted with 180-degree ambiguity for some unknown electronic reason. It was at 2800 megacycles, a common frequency for
S-band search radars.
However, after the lobe swung dead ahead, his earlier hypothesis had to be abandoned for it continued swinging over to the 11 o'clock position
and continued downscope on the port side.
Clearly, no 180-degree ambiguity was capable of accounting for this. Curiously, however, this was so anomalous that McClure did not take it
very seriously and did not at that juncture mention it to the cockpit
crew nor to his colleagues on the other two monitors. This upscope-downscope orbit of the unknown was seen only on the ALA-6, as far as I could
establish. Had nothing else occurred, this first and very significant portion of the whole episode would almost certainly have been for gotten by
Map of the RB-47 UFO encounter.
The signal faded as the RB-47 headed northward to the scheduled turning point over Jackson, Miss.
The mission called for simulated detection and ECM operations against Air Force ground radar units all along this part of the flight plan, but other
developments intervened. Shortly after making their turn westward over
Jackson, Miss., Chase noted what he thought at first were the landing lights of some other jet coming in from near his 11 o'clock position, at
roughly the RB-47's altitude. But no running lights were discernible and it was a single very bright white light, closing fast. He had just alerted
the rest of the crew to be ready for sudden evasive maneuvers, when he and McCoid saw the light almost instantaneously change directions and rush
across from left to right at an angular velocity that Chase told me he'd never seen matched in his flight experience.
The light went from their 11 o'clock to the 2 o'clock position with great rapidity, and then blinked out.
Immediately after that, Chase and McCoid began talking about it on the interphone and McClure, recalling the unusual 2800 megacycle signal that he had
seen over Gulfport now mentioned that peculiar incident for the first time to Chase and McCoid. It occurred to him at that point to set his #2 monitor
to scan at 2800 mcs. On the first scan, McClure told me, he got a strong 2800 mcs signal from their 2 o'clock position, the bearing on
which the luminous unknown object had blinked out moments earlier.
Blue Book file card for the case
Provenzano told me that right after that they had checked out the #2 monitor on valid ground radar stations to be sure it was not malfunctioning and
it appeared to be in perfect order. He then checked on his #1 monitor
and also got a signal from the same bearing. There remained, of course, the possibility that just by chance, this signal was from a real radar down on
the ground and off in that direction. But as the minutes went by,
and the aircraft continued westward at about 500 kts. The relative bearing of the 2800 mcs source did not move downscope on the #2 monitor, but kept
up with them.
Flightpath of the RB-47 (dotted line) and of the UFO (plain line), drawn on their formal report by the captain of the crew.
Sources and references:
The RB-47 UFO Encounter - UFO evidence
James E. McDonald, "Twenty-Two Years of Inadequate UFO Investigations" (1969)
This case study by atmospheric physicist -- and leading UFO researcher -- James E. McDonald is excerpted from his paper presented at the American
Association for the Advancement of Science (AAAS) UFO Symposium, 1969. R
RB-47 UFO Case Study
James E. McDonald, PhD., Astronautics & Aeronautics, July 1971
Case report on the RB-47 UFO encounter, by Dr. James E. McDonald, for the UFO subcommittee of the American Institute of Aeronautics and Astronautics
The RB-47 radar visual multiple witnesses cases, July 17, 1957
UFOs at Close Sight (Ufologie.net)
Articles, background, and further references for the RB-47 encounter.
Roy Craig, in the Condon Report, 1968
Roy Craig, in the Condon Report, 1968
The RB-47 incident was one of the cases examined by the University of Colorado UFO study (the Condon Report), with Roy Craig as investigator of the
Top 100 UFO Cases - Revealed! - By Isaac Koi
Special thanks to Isaac Koi
for providing me with informations and sources about this case, thank you, Isaac
[edit on 20/5/2008 by internos]