Cooper paid little attention to a "destination" and was almost solely interested in just getting the airliner off the ground again.
Fine, however this should not be taken solely at face value, nor should anything Cooper did be done so. It should not imply he didn't ultimately care of his final destination. And its irrelevant, because the manipulation of the destination, would come later, by telling them to fly at FL100 and flaps at 15. At the time, sure, he'd want to get the bird in the air, where he would be more safe, and in control, along with possibly wanting to the get the caper on the road as so he can jump in some semblance of ambient light. After getting in the air, he could instruct the pilots, as again he was in full control, to then fly where he wants. Remember he knew a cavalry would be waiting for him when jumping, so everything would be done to decieve and mislead the authorities, into getting them in the wrong spot.
I simply do not believe the duality that this has gone unsolved and at the same time, and he 'winged' it on where he'd land in the forest, with no planning.... I believe his exit strategy was the most important and planned part of his caper, which includes the jump area, and may even include a man on the ground
Dice,
First, there is no such thing as "FL100".
Basically, "Flight Levels" in the USA start at 18,000 feet above sea level with all aircraft setting their altimeters to "29.92 in Hg" at and above that altitude. There are some relatively minor variations on the altimeter settings due to unusual atmospheric pressure conditions and the appropriate altimeter setting would then be provided by air traffic control.
Flight operations at and above FL180 (18,000 feet) and up to FL600 (60,000 feet) are under IFR flight rules. Above FL600 (60,000 feet), flight operations are under VFR flight rules.
Cooper planned a night jump from the outset. Sunset that day was at about 4:45 PM PST in Seattle and, with all the clouds, there would be a very short (just a few minutes) twilight period. Cooper specified that the money and parachutes be ready by 5:00 PM PST and would not permit the airliner to land until they were ready. The airliner actually landed at SEATAC at about 5:30 PM PST (this time is not precise).
The airliner took-off for Reno at 7:36 PM PST which was almost three hours after sunset. With the cloudy weather, it was pitch dark at that point. Cooper's only input into the flight path south was to agree to the flight crew's statement that they would need to land at Reno (or some other point) to refuel and then would still need another refueling point in order to make it to Mexico. Cooper did not specify Reno or any other refueling point, the flight crew did that. There was no further discussion between Cooper and the flight crew about flight paths. And the airliner flew to Reno just as they had suggested. Basically, Cooper only specified that they fly south although he did mention Mexico early on. However, the airliner could not fly from Seattle to Mexico with the aircraft configuration Cooper specified, which Cooper should have known if he had previous experience with the 727.
So whether you believe it or not, there is no evidence at all that Cooper did any detailed planning for this hijacking.