Part 75, page 6
DB Cooper-32431Serials 164-2111, SE 164-81, SE 164-81-1844
Document date 10 January 1972
Another copy of this document is the primary, most legible copy: read it.
FBI 164-81, Vault Part 75 p. 6 (DB Cooper-32431), Memo, dated 10 Jan 1972, serial SE 164-81-1844 (as read from the transcript) — cooper.theunsolved.net/parts/Cooper-Part-75/pages/6
Transcript
The scan is the source; the transcript is machine-generated from it.
DIRECTOR, FBI (164-2111) January 10, 1972
SAC, SEATTLE (164-81) (P)
NORJAK
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There is being sent under separate cover a copy of a film taken by the U. S. Air Force cameraman from a chase plane adjacent to the Northwest Boeing 727 during the simulated flight made on January 6, 1972 to determine the reactions of the airplane to the dropping of approximately 235 pounds from the rear steps in the same manner which is believed to have been used by the hijacker.
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A review of the film shows the normal flight, together with a depression of the stairway as the load descends on the steps.
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The Bureau is requested, if it desires, to review the film and then return it to the Seattle Office, it being the original copy. A copy has been made of the film for the U. S. Air Force per their request, and Northwest Airlines for its review.
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There are also enclosed in the same package sequential black and white still photos showing the depression of the rear stairway by the addition of the sled and the reaction of the stairway to the actual departure of the sled, it being noted that the stairway immediately returned to a near closed position when the weight was taken from it.
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3 - Bureau (1 - Package) 2 - Seattle JEN/cjw (5)
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Sub AA 164-81-1844
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DB Cooper-32431