Air Force Project Blue Book Special Report 14 (Hynek's annotated copy)

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

# DEPARTMENT OF THE AIR FORCE Office of Public Information Washington 25, D. C.

U. S. Air Force Summary of Events and Information Concerning the Unidentified Flying Object Program

The Air Force feels a very definite obligation to identify and analyze things that happen in the air that may have in them menace to the United States and, because of that feeling of obligation and pursuit of that interest, the Air Force established an activity known as the Unidentified Flying Object Program.

This program was established in 1947 when unidentified flying objects were being reported in various parts of the United States. The reports of sightings reached a peak of 1,700 in 1952 and dropped to a total of 429 in 1953. During the first nine months of 1954 only 254 sightings were reported.

From a survey of the volume of sightings received by the Air Force, it has been determined that over 80 percent are explainable as being known objects. Generally, sighted objects fall into the category of: balloons, aircraft, astronomical bodies, atmospheric reflections, and birds. All reports of unidentified flying objects result from either radar or visual sightings.

Explanations pertaining to sightings reported from military and civilian radar facilities are as follows:

1. Temperature inversion reflections can give a return on a radar scope that is as sharp as that received from an aircraft. Speeds of these returns reportedly range from zero to fantastic rates. The "objects" also appear to move in all directions. Such sightings have resulted in many fruitless intercept efforts.

To possibly bear out the theory of temperature inversion reflection is an incident which occurred in January 1951 near Oakridge, Tennessee. Two Air Force aircraft attempted to intercept an unidentified "object" and actually established a radar "lock" on the object. Their altitude at the time was 7,000 feet. The unidentified object, according to their radar, appeared to be at an elevation of 10 to 25 degrees from this altitude. Three passes were made in an attempt to close on the object. In each instance the pilots reported that their radar led them first upward and then down toward a specific point on the ground. (One scientific theory holds that light can be similarly reflected from a layer of warm air above the earth. If this proves to be correct, many visual night sightings could be accounted for.)

2. Ionized clouds have caused some unidentified radar returns. Thunderstorms are identifiable by radar and radar returns have also been received from ice formations in the air, balloons, ground reflections, frequency interference between other radar stations, and wind-born objects. Obviously, such returns are very difficult to identify, especially when they occur during darkness.