Let me provide some background on my involvement with the Western Flight Path.
At first I saw the FBI Flight Path and didn't question it. Why would I? However, it didn't take long before I realized that there were some major problems that I could not reasonably explain away. Specifically, the fact that nothing had been found in the FBI search along the FBI Flight Path, and the fact that the money was found at Tena Bar.
Later I came upon R99's analysis of the placard drift that was posted on Tom Kaye's site--I believe the conclusion was that it drifted 2.7 miles to the northeast. This wasn't a shocking thing in my mind but notable.
However, I still had a hard time explaining why 305 was flying so erratically according to the FBI Flight Path especially considering the pilots were afraid that there was a live bomb in back that could easily detonate if it fell off a chair, and because the pilots appeared to be extra sensitive about DBC's "No funny stuff" comment." Indeed, they didn't even squawk 7700 because they were afraid DBC would interpret that as "funny stuff."
Then I read R99's theory about the jet flying directly from Maylay to Canby--I don't believe he referred to this as the Western Flight Path per se because I think I came up with that term--but it made a lot of sense considering some of the problems that I identified with the FBI Flight Path.
Later I got my hands on an actual placard which enabled me to provide R99 with some updated size and weight numbers for the placard that he could use to reevaluate the placard's drift. Also, Tom Kaye provided updated and more accurate weather data. In the end, R99's new placard drift analysis showed a much longer drift for the placard which I immediately realized created a very big problem for the FBI Flight Path and also lined up perfectly with the Western Flight Path.
Next, there was the discovery of the FBI file that told the story of the fiberglass skirt find. This too immediately suggested a problem with the FBI Flight Path and pointed to a path out of Seattle that I suspected all along--in other words, a due south departure and heading for the first several miles as the plane gained speed and altitude with gear down, flaps down, and airstairs ajar.
Ultimately all of this convinced me that some version of the Western Flight Path was the true path and it got me thinking about where the FBI Flight Path came from. This caused me to eventually theorize that the FBI Flight Path was probably crafted using radar data from their own F-106's, albeit accidentally. In other words, the circuitous FBI Flight Path was actually the path of the F-106's and not 305.
I closing, I realize that R99 and I carry a unique burden in that we are obligated to prove that the Western Flight Path is right and that the FBI Flight Path is wrong. I say this because we are the ones challenging conventional wisdom which places the burden on us to convince you that we're right, and not necessarily the other way around.
Nonetheless, I think a thorough assessment of the facts as we know them tend to support the Western Flight Path and disprove the FBI Flight Path. Of course, I realize others are going to disagree.