Project Blue Book Special Report (second copy)

These 12 sightings can be classed into four categories on the basis of
their shapes, as follows:
M (l) Propeller shape - Case I
m
(2) Aircraft shape — Cases II and III
(3) Cigar shape - Cases IV and V
(4) Elliptical or disc shape - Cases VI to XII
The criterion for choosing the above sightings was that their descrip-^1
tions were given in enough detail to permit diagrams of the objects to be
drawn. It might be noted here that in all but one of these cases (Case XI)
the observer had already drawn a diagram of what he had seen.
The objective of this section of the study was the conceiving of a
model, or models. The requirement that the description be detailed is an
important one, and was the easiest to determine in the re-evaluation pro-
gram. However, a good model ought to satisfy the following conditions as
well:
(1) The general shape of the object and the maneuvers it
performed should fit the reports of many of the UNKNOWNS
and thus explain them. i
(2) The observer and the report should be reliable.
(3) The report should contain elements which should have
been observed with accuracy, and which eliminate the
v possibility that the sighting could be ascribed to a
familiar object or to a known natural phenomenon.
(4) The model should be derived from two or more good
UNKNOWNS between which there is no essential conflict.
It can_bji_jLhciWji_ih^l-it-is not possible to deduce a model from the 12.
cases that will satisfy all of these conditions. The following case-by-case
discussion of the 12 good UNKNOWNS will illustrate this point:
(1) Case I does not satisfy Conditions 1 and 4. The reported
shape of this object is not duplicated in any of the other
UNKNOWNS.
(2) Case II does not satisfy Conditions 1 and 3. There are
very few UNKNOWNS in the aircraft shape classification. ^
In addition, the unusual characteristic of this sighting
(i.e. , the red glow) could have been reflection of the
lights of Flint from the objects if they were either birds
or aircraft.
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