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

US Air Force, Air Materiel Command · 1949-08 · 413 pages · text by OCR

This August 1949 technical report from the US Air Force Air Materiel Command presents Project Grudge's investigation of unidentified flying objects through January 1949. Drawing on consultants including Dr. J. A. Hynek, Rand Corporation, the Air Weather Service and Dr. P. M. Fitts, it explains most of 244 incidents as balloons, aircraft, astronomical phenomena, hoaxes or psychological errors. It concludes the objects pose no direct threat to national security and recommends reducing the investigation in scope.

Open the PDF at page 60 Original source ↗

Incident 921. Desiccates, Iowa - 29 June 1947

there is no serious astronomical explanation for this incident.

If the estimate of size can be given any erodence at all, the objects could not have been farther than five miles away; this is an absolute upper limit, and objects probably were very much closer.

Cases discussed

The Ghost Rockets (Spökraketer), Scandinavia, 1946 1946
summer of 1946... mysterious aerial objects in Sweden, the "ghost rockets"
The Kenneth Arnold Sighting 1947
report of Kenneth Arnold of Boise, Idaho... Incident Number 17
The 1947 Flying Disc Craze: America's First Flying Saucer Wave 1947
Within the month following Arnold's report, the number of incidents reached a peak
The Green Fireballs over New Mexico 1948
"green fireballs" reported in the general vicinity of Albuquerque, New Mexico
The Fukuoka F-61 Black Widow Radar-Visual Intercept 1948
Incident No. 183... Fukuoka Area, Japan. Airborne radar observer in F-61

About this file

Report, from the classic collection. The PDF is mirrored here; the original link is under it. The text was read from the page images by an OCR model; expect the odd misread word. 413 pages are in the text index: search them above, or from the library's search.