Documents / Document
This US Air Force Project Blue Book case file on Kenneth Arnold's sighting of nine objects near Mount Rainier, Washington, on 24 June 1947 was released through The Black Vault. It contains the Project 10073 record card, which concludes the objects were a mirage, plus Arnold's telegram, questionnaire data and interview notes. It also includes J. Allen Hynek's analysis arguing the objects were closer and slower than Arnold estimated. Other items are David Johnson's sworn statement on a Boise sighting, a Tacoma investigation telegram and news clippings.
Read from the scan by GLM-OCR; expect the odd misread word.
of the length of this particular ridge revealed it was approximately five miles, so it was estimated the chain of objects was five miles long. Mr. timed the objects between Nt. Henier and Mt. Adano and determined they crossed this 47 miles in one minute and forty-two seconds. This is equivalent to 1656.71 miles per hour. In a subsequent interview Mr. described the objects as appearing like saucers skipping on water. This description was shortened to flying saucers by some of the newspaper men and resulted in the popular use of this term. It is the Air Force conclusion that the objects of this sighting were due to a mirage. Mr. Arnold's statement concerning how smooth and crystal clear the air was is an indication of very stable conditions. These stable conditions are associated with inversions which increase the refraction index of the atmosphere.
Document, cited by the archive. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 62 pages are in the text index: search them above, or from the library's search.