The story of the flares is very interesting. I can't seem to locate anything in the FAA files. I also had someone look up the incident. I would love to back this up with some sort of documentation. I'm just wondering why the flares would be used. Cooper had to have known he was being followed. if he was an experienced jumper, would he need flares for wind direction, or location?
I'm not offering or hinting at any conclusions, but the only reference or documentation of lights in the sky / flares that I have been able to find, so far, is a record of a meteor shower around the time of November 16, 17.
There was supposed to be quite spectacular "Leonid" meteor showers at a rate of about 170 per hour in November, 1971.
Not saying that they would be mistaken as flares and someone might have been off on their timeline, but it has been documented that meteor showers
have been mistaken for UFOs in the past, so there's that.