C ( [redacted] )
Engineering Division
Memorandum Report No. MCREXD-694-18D
25 April 1949
UNCLASSIFIED
maneuvering or not maneuvering. It is quite possible that it was
simply climbing steeply on a relatively straight course, such as would
be taken by a lighted weather balloon.
As a matter of fact, a lighted weather balloon was released by
the Fargo Weather Station within 10 minutes of the time the light was
first sighted by the F-51 pilot. It is the opinion of the writer
that this lighted balloon easily could have accounted for all of the
pilot’s observations. (It should be noted that the standard 30 inch
and 65 inch weather balloons have a vertical speed of about 600 and
1100 ft./min. respectively.)
General Discussion and Summary
In the preceding section the hypothesis has been advanced that
most reports of unidentified flying objects have been the result
of persons failing to identify familiar phenomena, such as reflections
from bright surfaces in the day or lights in a night sky. It is
believed that this explanation will account for many of the reports.
However, some reports undoubtedly have other explanation.
Vertigo. The term vertigo covers a large group of miscellaneous
phenomena including air sickness, disbelief in one’s instruments,
and partial loss of orientation. The conditions under which some of
the observations of flying objects were made were such that they could
have produced loss of orientation on the part of an observer. This
is especially true for those experiences occurring at night and those
in which attempts were made to “chase” the object. Movement is always
relative. If the only outside reference is a point of light, and both
the observer and the object observed are moving, it would be practically
impossible under certain conditions to tell which was moving and
which was not, or to separate out the two notions. It is hard enough
[redacted]
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DOWNGRADED AT 12 YEAR INTERVALS: NOT AUTOMATICALLY DECLASSIFIED. DOD DIR 5200.10