The primary paradox in the Cooper case has been the discrepancy between the Tina Bar find and the original jump location near Ariel, Washington. Water flows to the Lewis River in Ariel, where it dumps into the Columbia downstream from where the money was found. The money would not move upstream on its own, so something has to give. One way to cover the paradox is to move the jump zone. And it has to move a considerable distance in order to get the money upstream from Tina Bar. This has led to numerous theories, including the infamous Washougal Washdown theory.
The timing and location of the jump could probably be pinpointed with the original radar information and data from the flight recorder but neither source is available anymore, so finding the true jump point will have to be made from other evidence, including eyewitness accounts.
First, let me mention that arbitrarily changing the drop zone based only on the Tina Bar find is a fallacy since we don’t know how the money got there with 100% certainty. There is room for mechanical and human intervention in how the money was transported from its original starting position to Tina Bar. I prefer simpler explanations, but nothing is off the table.
For simplicity, until other evidence is found which calls into question the original flight path, we shall adhere to the pre-existing evidence regarding where and when Flight 305 was during the times mentioned below. The key to eliminating the paradox is working the original evidence and finding out why the authorities calculated a drop zone near Ariel and why that was or was not in error.
Oscillations and the Pressure Bump
The main confusion in the eyewitness reports is whether there is a difference between the reported “oscillations” and the “pressure bump” caused by the stairs snapping back against the fuselage when Cooper jumped. Strictly speaking, we can’t be sure there were two separate events. We know the pressure bump happened because it had to, testing showed this was the case. Whether the pilot, in this case Rataczak, felt any kind of disturbance through the stick as Cooper crept out over the stairs is unknowable. Rataczak clearly believes he did, whether this was the oscillation or the pressure bump or turbulence, we can’t know.
What we do know is the cabin crew keenly felt something. Anderson, the flight engineer, had pressure gauges on his panel and they would have jumped around significantly during the pressure bump. The pilot would need to trim the aircraft after Cooper left. The entire cabin crew might have experienced ear popping from the momentary change in pressure. These pressure events were used in later hijackings to pinpoint landing zones for Cooper copycats like McCoy. The entire narrative here is undocumented, and we only get after the fact recollections.
For our purposes, we’re going to assume two distinct events. An oscillation which caused Rataczak to remark Cooper was “doing something with the air stairs” and was relayed over the radio around 7:11 pm, and pressure bump caused by Cooper’s jump sometime shortly after that.
-At 7:11, the cockpit reported Cooper was possibly “doing something with the air stairs” and relayed this information over the radio. It was overheard by a number of independent witnesses who were listening to these exchanges during the hijacking. This is the time generally given for the jump. In the released flight transcripts, nothing of consequence is communicated for the previous six minutes indicating this was the beginning of the jump ‘episode,’ not its conclusion.
-Harold Anderson, the flight engineer, said the time of the bump was not recorded, but that it happened “five to ten minutes” after the last communication with Cooper, a time generally given as 8:05 pm. This would give an approximate range of 8:10 to 8:15 for the jump, plus or minus a minute.
-In the summaries of the crew debriefs, documents available on the Cooper Forum website, Anderson says the pressure bump occurred when 305 had “not reached Portland proper but were definitely in the suburbs or immediate vicinity thereof.”
This gives some absolute barriers, Cooper did not leave before 7:10, and he was definitely gone by the time the plane was over Portland.
Another clue comes from the Time Table on Sluggo’s website, which gives us this little tidbit:
SEA CNTR advises Portland Altimeter (Corresponding Sea Level Barometric Pressure) is 30.03 inches of Hg. [This is important because it shows that at 20:15:56 they were very near Portland.]
Finally, “Shutter” (owner of the DB Cooper Forum) has been working on the problem of the flight path with what I’ll call “an extreme simulator” and did a test run from Ariel to Portland at my behest under nearly the same meteorological circumstances (he removed the cloud cover) and plane configuration of NWA flight 305. For my purposes, this simulation was mostly to get a view from the cockpit to better understand Anderson’s statement about being near Portland.*
My judgment, based on the simulation, is the absolute earliest someone from the cockpit could reasonably say they were near “Portland proper” is about five and a half minutes south of Ariel. This happened about 8:15 pm according to the published flight path. This is open to interpretation, and I encourage interested readers to see the video for themselves on the Project 305 YouTube channel. I’m being very conservative with the estimate, and I believe this to be the northern barrier for the drop zone.
All the evidence appears to overlap around the 8:15 mark. This is the upper limit of Harold Anderson’s statement of “five to ten minutes” after the 8:05 communication. At this location the flight was plausibly near enough to Portland both by my visual estimate from the cockpit and from the communications transcript.
It can’t be known exactly where 305 was at this instant, but the released FBI flight path suggests it is near Orchards, WA. It would be fair to say the flight could be plus or minus three miles north and south (one minute flying time), and perhaps one mile east and west from that point. This is significantly south of Ariel, very near the Lacamas River watershed, and it also makes a jump point over the Columbia River a possibility (though our estimate here is still a few miles and about a minute of flying time short of the Columbia).
Admittedly, the statements from the crew are ambiguous. None of the crew have spoken definitively on the flight path or about the pressure event. Only Rataczak has regularly spoken publicly about the hijacking, and his remarks on the subject is anything but clear. A strict interpretation, which is what others like Tom Kaye have favored, is what gives us the Ariel jump zone. By allowing for the possibility of two events and using the Ariel location for the start of the oscillation and using other evidence to establish the pressure bump, we get a drop zone farther south, closer to Portland and the Columbia River. This eliminates the paradox between where Cooper jumped and where the money was found, and does so without relying on the money find itself.
*Here is the entire paragraph from the FOIA document: Anderson stated that approximately 5 to 10 minutes after the last contact with subject at 8:05 pm, they heard and felt an oscillation of the aircraft and commented that the hijacker could have departed causing the unusual vibration since there had been no change in flight parameters or any other external force which would account for this sudden vibration. They telephoned the company representative (redacted) shortly thereafter and stated that the ‘oscillation’ which could have been the hijacker’s departure, would have occurred between 8:05 pm and their call to the company 5 or ten minutes later, the exact time being recorded in the company log. Anderson stated that they had not reached Portland proper but were definitely in the suburbs or immediate vicinity thereof.