The FBI seems to have run a campaign of confusion and disinformation citing -7 as one example, when in fact it was -7 Celsius (not Fahrenheit) and that was the temp aloft, not at ground level anywhere in the projected LZ at the time. (-7C = 19.4F) Shoes came off. Jaw got displaced when money bag tied around his waste flew up and knocked him out cold. His arms were pulled out of their sockets. (His members were eaten off by a grisly bears when he landed! Bears wait for things to fall from the sky and pounce and those things and eat them, immediately!) All of these accounts and projections were countered and rebutted by experts in the newspapers almost as fast as the FBI could write the scripts! Some of these projections actually came from the Boeing Sky Diving Club members.
On the other hand the FBI had asked for and received advice on what 'might have happened' from entities like the Boeing Sky Diving club. I talked to Dick P. on that club and he told me their assessment was serious and very negative in Cooper's regard immediately after the hijacking. Then one member of the Boeing club dissented and granted an interview. Dick said the whole thing became a circus of conflicting advice. Then Boeing got serious and shifted their focus on how to prevent hijackings of this type in the future - the "Cooper Vane" resulted.
One of the interesting aspects of the Cooper case - and perhaps by extension the actual wind velocities in the Vortex - is comparing the analysis of skydiving experts on the probability of DBC making a successful jump.
1. Earl Cossey has strongly advocated for BOTH conclusions. First he told his family that Cooper most likely made it, and also told the FBI that Cooper didn't have to be a pro to make it. Then a couple years later he completely reversed himself and declared that Cooper was a whuffo that most likely "cratered."
2. Ralph Hatley, the noted skydiving champion in Eagle Creek, Oregon, not only told me that he could have made the jump and he fully believes that Cooper did, too, he DIDN'T know that his good friend Earl Cossey had shifted his belief. RH looked stunned when I told him that ol' Coss was leading the charge that Coop didn't make it.
3. Eagle-Eyed Pete, aka Sheridan Peterson, aka "The Perfect Suspect," first told FBI investigators that Cooper died in the jump because of all the stuff that Cossey was saying, ie: DBC picked a bad chute, wasn't dressed for the occasion, lousy night, bad weather, bad terrain, etc. But then Ol' Petey reversed himself, too! In the History Channel broadcast the Eagle-Eyed One said he couldn't have made the jump successfully, no doubt about it.