Chaucer

The analysis of the tape is inaccurate because the FBI was using the time of the oscillations, not the time of the pressure bump.

I think the actual term used is "bob", not "blob". As in "bobbing up and down". I don't think this is particularly important. It could simply provide and earlier start time of the oscillations. 8:09 vs. 8:10. One thing that is interesting is that this document states that the plane was on autopilot as it flew south from Seattle. Rataczak has stated the exact opposite. He said they flew by hand because they were not sure how the plane would respond with the aftstairs fully extended in flight.

I agree with you that there are too many variables to get a precise time for the jump. I do believe that the flight path on the yellow map is generally accurate. My guess is that between 8:10 and 8:14, Cooper began messing with the stairs before slowly making his way out and down the stairs, perhaps taking time to throw items out. Then around 8:16/8:17, he jumped. That would line up with the crew’s statements about being in the “immediate vicinity” of Portland. But, you’re right. There is no evidence of this and no way to prove it unless new information become available. I’m curious about this 8:09 “blob” you speak of. Can you elaborate? Lastly, thanks for the heads up about the misaligned marks. That makes sense.

I’ve noticed a discrepancy in the plotted FBI flight path. I was hoping someone might be able to provide an explanation.There is point plotted to the northeast of Pearson Airport just outside of Vancouver. The next plot visible is the one adjacent to the I-5 bridge leading into Portland. The problem is that those two points are over 5 nautical miles away from each other which would require 305 to suddenly increase its speed to over 330 knots. A more reasonable explanation is that there is another missing minute. There should be a plot point midway between these two near where Marine Park is today. Any ideas?

Flyjack, I have done a similar analysis and I worked out a 135 nautical mile FBI flight path from 7:36 to 8:22. That works out to 2.93 nautical miles per minute or a ground speed of 176 knots. I agree that the missing 8:04 is simply a missed radar return. Regarding the 8:11 time: that is the reported time of the oscillations. The FBI continually confused and conflated the two things, and that has led people today to do the same thing. There is no way to know if the oscillations ended at 8:12, but that is the last time they were reported by the crew. The pressure bump was never recorded or reported - at least in the public files. Even the FBI, after many years, realized this and moved the drop zone farther south to the Hockinson area. My guess is that it’s actually closer to the north bank of the Columbia. So, again, we need to clear up the confusion between the oscillations/fluctuations and the pressure bump. Two different things. Two different times frames. If you confuse the two, then you will end up thinking the pressure bump happened between 8:10 and 8:12. It didn’t. It happened after.

I think the interview is rather clear that they were experience minor pressure fluctuations that were hardly distinguishable from the “dirty flying” except on the gauges. Then there was one last sudden BUMP which ended those pressure fluctuations and which the crew concluded was Cooper left the plane. The oscillations were reported between 8:10 to 8:12. Thus, the pressure bump had to occur after 8:12. You are right that these times are not precise, but a difference of merely two or three minutes means 5 to 10 miles difference in location. I’m not sure we can ever determine the precise jump time with the current information we have...

I attribute this to the FBI’s confusion and conflation of two different events: the oscillations and the bump. I have no doubt the oscillations were happening at 8:11. The pressure bump happened at a later, unknown time.

Regardless, it doesn't change my overall point: The crew communicated "oscillations" at 8:12, not "pressure bump".

Yes, but even at 8:12 the crew typed a message on the teletype and only mentioned oscillations, not a bump. Also, Larry Carr later determined that the crew WAS NOT on the phone with NWA at the moment the pressure bump happened. The reported it later. So, the 8:11 time would not be accurate. The incident with the ear piece was determined NOT to be the same thing as the pressure bump.

I'm not disagreeing with anything you have posted here except that I can't comment on the speed change because I haven't looked into. Regardless, I'm talking about time. The oscillations and fluctuations occurred first, and ended with the bump. According to Anderson, the oscillations and fluctuations did not occur again after the bump.

And my point is that the oscillations ended when the bump occurred. The bump can’t occur if the oscillations are still ongoing. You can’t give birth and still be pregnant.

The statements from Anderson and Rataczak would disagree. The statements from Anderson and Rataczak would disagree with that assessment. Here is what Anderson had to say: "...it wasn’t a one time event but a series of fluctuations which attracted our attention. I saw it first then alerted Scott and Bill, ending in a single pressure event we felt in our ears, and nothing following, not even more fluctuations. We waited to see if something more would happen but it didn’t." "These were minor oscillations. We detected on the guages only. We just presumed pretty quickly that it was Cooper fiddling with the aft stairs but we weren’t one hundred percent sure because we were already flying dirty, with throttles up and fighting icing and weather. A lot going on and it wasn’t totally smooth even before the oscillations started. What we noticed was the pattern of the oscillations was continuing and there was a very minor disruption of the slipstream. Scott said at first he wasn’t feeling anything for sure, then a little later he thought there was more drag and the nose was deviating a little. When the final bump happened and the oscillations stopped that sealed it. But even then we weren’t sure and we waited before calling anybody." "I monitored the guages and reported to Captain Scott. We all agreed that the guages were detecting a disruption of airflow, most likely caused by Cooper testing out the aft stairs. But we all felt one physically distinguishable "bump" with our ears which came abruptly after we had been monitoring the gauges. We all felt it said almost in unison, surprised, "there he goes!" It was the largest bump by far, an abrupt pressure change. We all thought he had exited the aircraft at that point, because the guages never detected any further major airflow disruptions after that ‘thud’. The re-test duplicated the oscillations and the pressure bump exactly. "

I don't believe it's the same thing. All other evidence points to the oscillations leading to the pressure bump. Again, there is confusion between the oscillations occurring at 8:11 and the pressure bump which did not.

Right, but not only opening the door, but also lowering the stairs and climbing out on them in-flight would also cause changes that would have been felt by the crew. And the oscillations were continuing between 8:10 and 8:12; therefore, the "pressure bump" had to have occurred after 8:12.

What instruments registered what?

Because that is when the oscillations were occurring. The pressure bump happened after the oscillations. If the oscillations were ongoing at 8:12 then the pressure bump had to have occurred after 8:12.

I don't think the "increase in cabin pressure" and the pressure bump are the same thing. I think the increase in cabin pressure described in the doc is part of the ongoing oscillations. Also, all crew statements that I am aware of state that the pressure bump came after the oscillations and that the oscillations ended with the pressure bump. I also don't recall anything about oscillations occurring after the pressure bump for the sled test either.

The only problem with this is that the pressure bump didn't occur between 8:10 and 8:12 because that is when the oscillations were occurring. Perhaps the crew felt the oscillations and slowed the aircraft, but regardless, Cooper couldn't have jumped any time before 8:13

Because that is how the crew described them. They assumed the oscillations were caused by Cooper "attempting to do something with the airstairs". Then the pressure bump occurred which we now know is Cooper jumping. Logically, one would conclude that Cooper climbing out on to the stairs caused the oscillations before he jumped. No where does it say, "Wow, we just experienced a significant pressure bump and now we are getting oscillations." Quite the contrary. It says, "We are getting oscillations." and then no mention of the pressure bump.

Yes, what the crew described as oscillations were fluctuations in the cabin pressure which they immediately assumed was Cooper "attempting to do something with the airstairs". The oscillations were not a one time event. They happened over a period of time while Cooper made his way down the stairs. Then, he jumped and when he did it caused a pressure bump which was noticeably different from the oscillations they had experienced immediately before. . In this file, the FBI again confuses the oscillations with the pressure bump. The oscillations were not caused by the airstairs slamming back up. The pressure bump was the result of the airstairs slamming back up. The oscillations were occurring at 8:11 and continued until 8:12 (maybe longer; we don't know). But at some time after 8:12, Cooper jumped and the crew experienced the pressure bump. Rataczak also states in the 302s that "they had not yet reached Portland Proper but were definitely in the suburbs or immediate vicinity." when the pressure bump occurred. That would have to be later than 8:10 or 8:11. No one is going to describe the Ariel area as the suburbs of Portland or in the "immediate vicinity" of Portland. They would have to be closer to Vancouver.

The confusion between the oscillations and the pressure bump has been ongoing with this case for years - probably from the beginning. The oscillations were an ongoing event. The occurred over a period of two or three minutes. This is likely Cooper slowly walking out on to the aftstairs. This is when the crew says "He must be doing something with the stairs." The pressure bump was a one time event that ended the oscillations. This was Cooper jumping from the aircraft. The oscillations are well-documented as occurring between 8:10 and 8:12. Conversely, the "pressure bump" is not mentioned and no time is given. We have to assume that it occurred AFTER the oscillations - 8:13 or later. Rataczak said it happened 5 to 10 minutes after last contact at 8:05. He later told Carr it was 10 to 15 minutes after last contact. Meanwhile, Anderson is on record stating that when the pressure bump occurred, they discussed it among the crew about what it was and what to do before they informed the NWO about it. After being informed by the crew, Sonderlind did his best estimate and put the time at 8:13. So, again, the oscillations happened for several minutes and ended with the pressure bump. We know when the oscillations begin, but we do not know how long they last nor do we know the exact time of the pressure bump.

Well. this still doesn't account for WHERE Cooper was when he jumped. Assume he jumped at 8:11. WHERE was that? Ariel? Battle Ground? Orchard? Portland? How can we know? Also, FJ, the speed you have is far above that indicated on the DME which is 165 knots.

Flyjack, Is there a way to contact you privately? I have something I'd like you to take a look at. Thanks.

So the comment “Mark your maps” is also anecdotal? Seems that the idea that Rat said “Mark your maps” or something similar and then Sonderlind looked up at the clock and noted the exact time of the jump is also anecdotal with no substance behind it. Regarding the timing, the oscillations and the pressure bump are two different events. The oscillations preceded the pressure bump. The pressure bump is not mentioned in any 302s except where it is confused with the oscillations. This confusion exists to this day. The time of the oscillations is recorded between 8:10 and 8:12 but the time of the pressure bump - the moment Cooper jumped - is unknown. Between Rat’s later statements that it happened 10 to 15 minutes after last contact and Anderson’s statements that the crew waited to report the pressure bump, it seems possible that the jump was later than the generally accepted 8:13.

It has been said that when the pressure bump happened, Rataczak exclaimed “There he goes!” and told ATC to “Mark your maps.” However, I can find no evidence of this in the transcript or the 302s. Where is the source of this information?