Dummy Chute Hypothesis
John S. has asked me to post his hypothesis on the use of the dummy chute to bounce the stairs downward, in the vicinity of Ariel, as a deception for his later exit over Woodburn, Oregon via squidding off the top step.
This thread seems like a good place to put this, even if the commentary between Flyjack and others is hot and heavy on the stairs at present.
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Greetings, everyone. This is my first post here. I was invited to the forum by Bruce A. Smith. I recently read his book, “DB Cooper and the FBI,” and was very impressed with it. I contacted him by email, and sent him some of my own thoughts about the Cooper case. He looked them over, and cordially suggested that I join the DBC Forum and post some of that information here so that others could consider it and discuss it.
Based largely on information I found in Smith’s book, I came to the conclusion that a major clue about the Cooper case might have been largely overlooked - the dummy parachute. Everyone seems to know about it, but no one seems to give it much thought. Here are my thoughts on it. I offer this theory to the Forum for your consideration.
The dummy parachute - Was it used as a projectile to simulate a jump?
As a working premise, I make the following assumptions:
Cooper was a commando. All of his movements were planned, rehearsed and practiced ahead of time. He knew exactly what he was doing. He did the skyjacking as any commando would do a professional job.
My Theory - The dummy parachute might have been used as a projectile to simulate a jump:
Cooper might have used the dummy parachute as a heavy projectile to simulate a jump, before he made his real jump. The purpose would have been to put time and distance between Cooper and his pursuers. A short while later in the flight, Cooper made his real jump. This theory applies to any unopened parachute - whether dummy or real.
My reasoning in support of this theory:
The so-called “dummy parachute” didn’t arrive in Reno. That implies Cooper used it for some purpose, and in the process of using it, he tossed it out of the plane. Why? How could the dummy parachute possibly be used by a commando doing a skyjacking job, and why was there a need to throw it out of the airplane in the process?
I personally can’t think of any practical use for an unopened parachute, dummy or real, in tossing it out of an airplane - except one. It could be used to “bash” into something directly below it.
Cooper could have deliberately lobbed it at a target just outside the airplane, and used the weight of the parachute for impact against that target. The only target available to Cooper was the partially-lowered aft-staircase.
Cooper could have lobbed the unopened parachute in a high arc outward and then down toward the bottom of the lowered staircase. The parachute weighed about 20 pounds. For each foot it drops, it would impact the staircase below it with 20 foot-pounds of force. If Cooper lobbed it upwards 8 feet (2 feet above his head) and the bottom of the stairs was down 4 feet, it would impact the bottom of the staircase with 240 foot-pounds of force. That’s enough impact force to bounce the stairway downward, considerably.
The sudden impact on the bottom end of the stairway would cause a “dip” in the tail section of the plane. A “dip” was duly noted by the pilots and crew of Flight 305. The pilot “trimmed” the flight path to correct for this sudden movement in the tail section of the plane.
But the crew also noticed something else around this time. The cabin pressure stabilized momentarily, and they interpreted that to mean that the aft-staircase had rebounded hard enough to slam shut.
The combination of the “dip” and the aft-staircase slamming shut on a rebound, convinced the crew that Cooper had probably jumped at that time and location - 8:13 pm over southern Washington. Within a short time, this version of the jump had become almost gospel with the public.
But this version of the Cooper jump is based entirely on the assumption that the crew on Flight 305 interpreted the data they witnessed correctly.
I’m going to challenge that basic assumption. I believe the southern Washington jump might actually have instead been a Cooper-created jump-simulation, intended to throw off his pursuers. Cooper may have used the dummy parachute as a heavy projectile to bash down onto the bottom end of the aft-staircase, in order to simulate a jump. If Cooper was a commando and he wanted to simulate a jump, then one of the easiest, low-tech ways he could do that would be to bounce a heavy object off the aft-staircase.
That action would dip the tail end of the plane, and then rebound the staircase rather hard. Whatever happened at 8:13 pm did cause the staircase to rebound hard enough that it actually slammed shut.
Now oddly enough, if this is what really happened, then Cooper may have actually taken it a bit too far.
From what I have seen on a few YouTube videos, people who jump off of the aft-staircase of a 727 do not create enough downward force to cause the aft-staircase to rebound that violently. Yes, it rebounds, but - by appearances - not enough to slam shut.
It is my understanding that reenactments have been done that show Cooper could have successfully jumped off the lower end of the staircase of a 727. But did these reenactments also show that the staircase rebounded so violently that it actually slammed shut? I don’t know the answer.
But if the reenactments show that the staircase doesn’t rebound enough to slam shut, then that might be considered evidence that the significant “dip” and the change in air pressure felt by the crew of Flight 305 were not caused by a real jump. If that is true, then Cooper may have lobbed the dummy parachute just a bit too hard for simulating a real jump off of a 727.
Something heavy did go out the door of Flight 305 at 8:13 pm over southern Washington. We know that from the flight crew. If it wasn’t Cooper, then it might have been the dummy parachute. And Cooper might have used the dummy parachute to simulate the effects of a jump. But if he did, then that brings up a parallel issue.
If Cooper knew how to simulate a jump, then he also knew how to disguise one. It’s two sides of the same coin. Cooper wouldn’t want to throw off his pursuers in one location, just to attract them back in another location. So Cooper also needed to disguise his real jump. How could Cooper do that?
I came across one possible way for doing this, mentioned briefly in Smith’s book. It is called “squidding.” I always thought “squidding” meant simply that the parachute failed to open for the jumper. Apparently there is also another use for this term. In this other form, “squidding” is a jumping technique. Apparently it means the jumper holds onto the doorway of the airplane (somehow,) lets his parachute “squid out,” and then waits - hopefully - for the canopy to blossom out in full, pulling the jumper straight back off of the plane.
I have no idea if this technique actually works. It is only a suggestion. But if it does work, then it could be one explanation for how Cooper might have exited Flight 305 without creating a noticeable “dip” motion in the tail end of the plane in flight. “Squidding out” of Flight 305 might have disguised Cooper’s real jump rather well.
I’m not qualified to say anything more about this “squidding” technique, because I have no expertise at all in skydiving. I’ll leave that completely up for discussion by others who do. I simply mention it here as a possibility I read about, because I saw it mentioned in Smith’s book.
CONCLUSION:
Here is the theory I am offering to this forum for consideration:
1) I think D.B. Cooper might have used the dummy parachute as a heavy projectile to simulate a jump.
2) If he did, then I think D.B. Cooper also used another planned technique to disguise his real jump.
How? I really don’t know how. That’s why Bruce suggested I post it on this forum, for consideration. Maybe somebody else can figure out how. And that’s the spirit in which I am posting this theory here on this forum, simply “for your consideration.”
Best wishes to all, John S.
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