FBI file 62-HQ-83894, section 7

To date, the Air Force has undertaken to investigate and analyze .ab~ut
1500 reports dealing with these phenomena. AB before, most of the reports were
identified and disposed of as friendly aircraft erroneously reported, known
electronic and meteorological phenomena, light aberrations, hoaxes, and other
lmown natural occurrences or man-made objects.
The unexplained reports, however, which are in the order of 20 percent of
the total, cannot be definitely associated with these familiar things.
Difficulty in Evaluating Reports
The difficulty in disposing of these unexplained reports is based largely
upon the insufficiency of accurate basic data such as size, shape, composition
and flight characteristics (speed, acceleration, altitude, exact maneuver pattern,
etc.) of the objects.
Although some instruments which are useful in obtaining more accurate data
of this type have been available, the reports baaed on sightings with these
instruments have been very infrequent and comprise an extremely small percentage
of the total. Moreover, even these reports have not included much of the
information required.
Because of the inadequacy of this basic data, the Air Force has in the past
devoted its efforts primarily to determining whether these unexplained sightings
indicated the existence of a menace to the United States. Initially it was
believed that some pattern might evolve from tho study of a large volume of
reports. To date, no pattern has materialized to reveal anything whatsoever
which can be interpreted as indicative of purpose or consistency or which can be
construed as a menace to the United States. Nonetheless, since these unexplained
sightings persist, the Air Force will continue its investigations, giving the
problem adequate but not frantic attention.
It is now felt, however, that reports from people whose training and
experience in observing aerial objects qualify them to obtain essential data
are the only ones likely to produce material suitable for systematic analysis .
The Air Force is planning to provide additional tools to help these observers
obtain the basic data it needs.
Reports of similar phenomena go back to Biblical times. There have boen
flurries of them in various centuries. The current series of sightings began
generally in 1946.
-There are many reasons why the volume of these reports has increased
materially during the past few years. Aerial activity originated by man ha.s
increased, and people today have a greater curiosity about this activity than
before. Also, our present efficient connnunication facilities and news media
provide an incentive for reporting unusual observations, for publicizing them
and for recording them. However, the ability to measure these phenomena does
not seem to have advanced in step with opportunities for observing them. Tho
Air Force believes that moat of these phenomena will gradually be understood .
as more 1~ lmown about occurrences in the upper atmosphere.