Unidentified Flying Objects: Project "Grudge" (Technical Report No. 102-AC 49/15-100)

5. 5160th Electronics Laboratory, Cambridge Field Station, studied all incidents by comparing evidence with research balloon data, to determine which incidents may be attributed to various types of research balloons.

6. Dr. P. K. Pitts, Psychologist, AIC Aero-Medical Laboratory was requested to review all material relative to sightings and to provide psychological and illusory information and determine human capacity for observing and remembering minute details of range, speed, size, etc.

While these analyses were being conducted, the Swedish Defence Staff was contacted through our Air Attache to learn the official Swedish attitude toward the "ghost rockets". The results of these requests are contained in AA Reports, No. IR-115-46, 30 December 1948, and No. IR-47-49, 2 March 1949 (listed as Appendix "A").

## V. Discussion of Reports of Consulting Agencies

A. Dr. J. A. Hynek, Final Report (see Appendix "B"). Dr. Hynek's report includes the results of a concentrated study of all files up to and including Incident No. 214. However, as mentioned above, Incidents 223 through 227 and 221 through 214, in the New Mexico area, will not be considered in this analysis. An additional seven incidents were excluded by Dr. Hynek as explained in his Summary on Page 4 of Appendix "B". Of the remaining 226 then treated, Dr. Hynek concluded that approximately 33% were astronomical with varying degrees of probability. He concluded that an additional 57% were not astronomical but suggestive of other explanations, such as birds, rockets, balloons, ordinary aircraft, etc. The remaining 50% as far as Dr. Hynek was concerned either lacked sufficient evidence or evidence offered suggested no explanation. In compiling these statistics, Dr. Hynek cautiously accepted each case at face value, without discarding evidence that sometimes "vurged on the ludicrous" and without taking into consideration psychological factors. Dr. Hynek then stated that 53% might conceivably be considered (although the likelihood of their being so may be very small) as extraterrestrial or astronomical in origin. These include "those which either are definitely astronomical or can by suitable manipulation of the evidence be construed as such".

B. Eq. Air Weather Service, one indemnment and one letter (see Appendix C) Air Weather Service conducted an analysis simultaneously with Dr. Hynek using the same evidence. AES attempted to determine whether a synoptic weather balloon could have been at the location where aighting was reported.

In this investigation consideration was given to the wind direction and speed at the surface and aloft at the scheduled time of balloon release, and the location of the nearest weather station making balloon observations. AES used files of the first 233 incidents.