A man who resembled the sketch was jumping from a school in California, making 3 or 4 jumps from the center in Elsinore California..
They recall conversations about certain aspects of jumping, including jumping out of jets. They told him it could be done if the door opened inward, or had a rear stairwell that could be raised or lowered. The man appeared interested and they discuss further, to the point where air speed and drag were talked about. The fact was brought up that full flaps and lowered landing gear would supply the drag needed to exit from a jet..
He also inquired about where jump centers were located in the northwest. He was told about three in the state of Washington..they stated that in his opinion someone contemplating a hijacking would ask those type of questions and thought it was strange that nobody else ever asked these questions. They also discussed altitudes, oxygen supply, and distance of free fall..
Then he claimed to have noticed that he smoked “Raleigh” cigarette's in which they discussed the coupons in which the man stated he was saving up for a P.C. Para Commander chute.
The FBI claimed that after viewing the registration cards (12,000) from the school noticed that most of them were between 25-28 years of age and they would not hang around an old guy like that.
He describes the individual he talked to in July, or August of 1971 as follows..
Race – white
Complexion -light
Age- 40-42
Height- 6' -6' 1” in boots
Weight – 165-175
Build – slim
Hair- dark brown thin on top, receding on both sides, front combed back, parted on left.
Now, was this Cooper, probably not, but it does show how simple information could have been obtained...
the file does state military experience was thought of due to the individual wearing "Cochrane" boots that were peculiar to military jumpers and not team, clubs, sport or novice.
a magazine "Look" dated August 24, 1971 on page 46, 47 shows a man jumping out of a jet aircraft that could of sparked the conversation...