That is something that the FBI, FAA, and/or NWA does not want released.
This would have to be the case right out of the gate, why, because Paul S. would see locations to gather information for the possible dropzone. if they were not redacted, how was he so wrong when locations were given or obvious things said that have been removed, plus they were listening?
Why would the FBI hold this back making them spend hundreds of thousands of dollars looking in the wrong location. In cases like this they rely on experts telling them important facts surrounding the crime. they didn't rely on NWO to catch Cooper, not there job.
The FAA is neutral and probably handed over the transcripts outside of what NWO already had and sent to the FBI?
Why would NWO cover up the location they spent a lot of time on. no other hijackings had such conspiracy theories attached to them.
Now, I can see them removing things they think would be damaging but how did Paul miss this info we don't see, it doesn't fly?
The FBI has a decades old rule, much like other law enforcement by not releasing info on an open case, even semi-open. it is what it is.
Lots of departments would be part of this conspiracy, the FBI, NWO, FAA, Portland, Reno, The flight crew etc.
In a nutshell, none of the above wanted the case solved and all paid way more than the $200,000 to cover it up?