Project Blue Book file, RB-47, July 17, 1957

Read from the scan by GLM-OCR; expect the odd misread word.

## By Philip J. Klass

This is an analysis of one of the most curious UFO cases on record. It illustrates that a UFO report which may at first seem to be explainable only in terms of an extra terrestrial spaceship can, when investigated in depth, yield a more plausible, if less exotic, explanation.

The case involves an Air Force RB-47 on a flight over four southern states (Mississippi, Louisiana, Texas and Oklahoma) during the pre-dawn hours of July 17, 1957. An account of the incident was published in the July, 1971, issue of the AIAA magazine Astronautics & Aeronautics (p. 66). It was written by the late Dr. James E. McDonald, an outspoken proponent of the hypothesis that the Earth is being visited by space ships from other worlds.

McDonald's investigation convinced him that an "unusual craft," which had the ability to fly at supersonic speed and to hover, had "played tag" with the RB-47 for approximately two hours. The presence of the "unusual craft," McDonald believed, was confirmed by three independent means: visual sightings by the RB-47 pilot and co-pilot; by electronic intelligence (Elint) equipment aboard the RB-47; and by an Air Defense Command ground radar located at Duncanville, Texas, near Dallas.

In another published paper on the RB-47 incident, McDonald called it "a case in which the reported phenomena appear to defy explanation in terms of either natural or technological phenomena." (UFO symposium sponsored by the American Association for the Advancement of Science in Boston, Dec. 27, 1969.)

My own investigation prompts quite a different conclusion, after a careful study of the same source material used by McDonald, followed by an analysis of the electronics equipment that figured so prominently in this UFO case.

An inherent difficulty in investigating any old UFO case, such as this one which occurred more than 14 years ago, is that the principals have difficulty in accurately recalling some details. A more serious problem is possible embellishment, due to the passage of time and repeated re-telling of the story. Embellishment need not be the result of a conscious effort to alter the facts. A principal may unconsciously report how he thinks he should have behaved at the time of surprise or stress, rather than how he actually did behave.

When an investigator must choose between conflicting accounts given by the same individual, where one account was made shortly after the incident and the other was given a decade or more later, generally the earlier version should be accepted -- unless there is physical evidence to support the later. (In the A/A article, the early account is referred to as the "contemporary" version.)

However, there may be an obvious error in the contemporary report. For instance, the Airborne Observer's Report prepared by RB-47 commander/pilot Lewis D. Chase with the aid of the navigator's log, diagrams the airplane's flight path and the time of major events. This report shows the RB-47 to be at two widely separated locations at the same time -- 10:30Z. From the airplane's reported airspeed, it seems certain that the second notation should be 10:30Z.

Where there is a discrepancy between early accounts of two crew members, the report by the individual most directly involved in the duty seems most likely to be correct. For example, in Chase's original report, the pilot said that the UFO did not show up on