Author Topic: General Questions About The Case  (Read 381186 times)

Offline Robert99

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Re: General Questions About The Case
« Reply #3285 on: January 17, 2022, 10:32:12 PM »
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To be clear, I will criticize all posts on the internet, in any forum, that don't mention me.
Seems like there was some misunderstanding about that.

Snowmman & Bruce, maybe you fellows need to look for a site that has posts in a simpler language or whatever it is that is "readable" to you.

uh.
I had looked around before landing here.
This was the bottom-of-the-barrel.
There is nothing else.

Weren't you on DZ a few years ago?
 

Offline Bruce A. Smith

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Re: General Questions About The Case
« Reply #3286 on: January 18, 2022, 03:29:09 AM »
Regarding readability, this forum is Paradise. Eric's Facebook site is like taking a stroll through a briar patch, only to get tangled in salal forest. I can't find a damn thing there except for those brief passages that mention me, or are in an email link that some poster might send me.

As for the DZ, I never go there at all.
 

Offline georger

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Re: General Questions About The Case
« Reply #3287 on: January 18, 2022, 03:46:04 PM »
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Regarding readability, this forum is Paradise. Eric's Facebook site is like taking a stroll through a briar patch, only to get tangled in salal forest. I can't find a damn thing there except for those brief passages that mention me, or are in an email link that some poster might send me.

As for the DZ, I never go there at all.

0+0+0+0+0+0+0+0 = 0      The salal forest never yields fruit. People keep trying.
 

Offline nickyb233

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Re: General Questions About The Case
« Reply #3288 on: January 20, 2022, 03:17:39 PM »
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But, as was discussed earlier and you seemed to agree with, they likely did not replicate the conditions that might have caused the lesser oscillations, i.e. Cooper venturing a bit down and up the stairs.

Pictures from the aft stairs test, it looks like a pretty rinky dink operation. You can see what looks to be a guy geared up hanging off the stairs. I don't I understand why they couldn't take N467US to Skylark Airport in Lake Elsinore or Perris Valley Airport in Ca. and take a load up. There would of been a line around the DZ!








« Last Edit: January 20, 2022, 03:35:59 PM by nickyb233 »
 

Offline snowmman

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Re: General Questions About The Case
« Reply #3289 on: January 20, 2022, 04:04:40 PM »
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To be clear, I will criticize all posts on the internet, in any forum, that don't mention me.
Seems like there was some misunderstanding about that.

There is no evidence that you can make stick around that assertion.
Plausible deniability. Even Edwards couldn't nail that down.
Snowmman & Bruce, maybe you fellows need to look for a site that has posts in a simpler language or whatever it is that is "readable" to you.

uh.
I had looked around before landing here.
This was the bottom-of-the-barrel.
There is nothing else.

Weren't you on DZ a few years ago?
 

Offline dudeman17

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Re: General Questions About The Case
« Reply #3290 on: January 21, 2022, 06:44:28 PM »
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You can see what looks to be a guy geared up hanging off the stairs. I don't I understand why they couldn't take N467US to Skylark Airport in Lake Elsinore or Perris Valley Airport in Ca. and take a load up. There would of been a line around the DZ!

You're certainly right about all of that!

I'm surprised to see the guy at the bottom of the stairs. Forgive me for not knowing this, but didn't they do that test out over the ocean? I wonder if they had a contingency for recovering him if he happened to fall off.
 
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Offline 73blazer

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Re: General Questions About The Case
« Reply #3291 on: May 01, 2022, 07:50:57 PM »
Mabey this has been answered somewhere but I just don't find it.
If the airstairs are hydraulically operated then why would they bounce back up to create the Rataczak pressure bump? I can't find specifics on the 727 airstairs hydraulics, but information available says they are pushed down and drawn back up by two hydraulic cylinders. I operate all kinds of hydraulic equipment and while you can move some without the actual hydraulic pressure being applied it will move very very slowly. I'm just wondering about the whole "bounce" back of the airstairs if that's even possible.   
 

Offline Shutter

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Re: General Questions About The Case
« Reply #3292 on: May 01, 2022, 10:54:49 PM »
Three systems are on the 727.. system A-B and a standby system. all are tied together. system A mostly does the flight controls, system B controls the main brakes and aftstairs..I believe they operate at 3000 psi..

The stairs didn't "slam shut" they came up rather slowly due to fighting the hydraulic system. this can be seen in the movie "The Pursuit Of DB Cooper"  flight 305 was going about 20 knots faster so the stairs might of retracted a little faster but no much IMO. even coming up slowly would cause disruption that would register on the control panel.
« Last Edit: May 01, 2022, 10:55:10 PM by Shutter »
 
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Offline 73blazer

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Re: General Questions About The Case
« Reply #3293 on: May 01, 2022, 11:23:46 PM »
So the 727 has the std (well ahead of its time really) three hydraulic circuits. That's fine. But the air stairs are hydraulically operated and I'd love to see the hydraulic circuits that control them on paper surely that has to exist somewhere. . I guess i was never convinced this pressure bump was the actual time of departure as I really don't think these stairs can come back up with any force as to produce any noticeable reading by the cockpit or anyone else. They supposedly reproduced this event shortly after is there written recorded evidence to this effect?  I dunno...just asking questions......
 

Offline Shutter

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Re: General Questions About The Case
« Reply #3294 on: May 02, 2022, 06:11:44 AM »
The aircraft is air-tight so any disruption will show on the gauge. the stairs almost closed once he left the stairs. the wind load on the stairs was extreme and kept the stairs almost closed until his weight was applied lowering them further putting a greater load on the stairs.

System A was powered by the engines, not sure which one and system B was AC powered, along with the standby system. YouTube has some video on the hydraulics..
 

Offline georger

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Re: General Questions About The Case
« Reply #3295 on: May 02, 2022, 10:59:43 PM »
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So the 727 has the std (well ahead of its time really) three hydraulic circuits. That's fine. But the air stairs are hydraulically operated and I'd love to see the hydraulic circuits that control them on paper surely that has to exist somewhere. . I guess i was never convinced this pressure bump was the actual time of departure as I really don't think these stairs can come back up with any force as to produce any noticeable reading by the cockpit or anyone else. They supposedly reproduced this event shortly after is there written recorded evidence to this effect?  I dunno...just asking questions......

see photos of the sled test which literally show not only the rate/time of the air stair retraction, and how far the stairs in those tests closed. Any change or disruption of cabin pressure for any reason will be noted by the gauge. You can calculate all of these parameters using known distances on the plane. The photos are consecutive frames by a camera with a known shutter rate ...

Does Edward's book cover this? 
« Last Edit: May 02, 2022, 11:16:24 PM by georger »
 

Offline 73blazer

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Re: General Questions About The Case
« Reply #3296 on: May 03, 2022, 01:34:47 PM »
It does, but I had just found his book yesterday ;D :rofl:
He says that it could be lowered and locked up to 300knots. He doesn't say it directly but I believe he's trying to say the stairs weren't locked during the sled test and they had to deliberately put them in this unlocked state in order to produce the pressure bump. I'm inclined to preliminarily agree with that, as hydraulic pressure should have zero problem to push those stairs down into the slip stream. Need a Boeing parts book for those hydraulic cylinders to see what their specs are. that exist anywhere?
Another interesting tidbit is I found from a Boeing maint. manual that the 2nd officers panel shows two aft airstairs lights. One is green and illuminates when the airstairs are down and locked. Another is amber and illuminates when the airstairs are not up and locked. Any if the statements or FBI materials mention which light(s) was illuminated?
« Last Edit: May 03, 2022, 02:13:44 PM by 73blazer »
 

Offline georger

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Re: General Questions About The Case
« Reply #3297 on: May 03, 2022, 02:08:25 PM »
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It does, but I had just found his book yesterday ;D :rofl:
He says that it could be lowered and locked up to 300knots. He doesn't say it directly but I believe he's trying to say the stairs weren't locked during the sled test and they had to deliberately put them in this unlocked state in order to produce the pressure bump. I'm inclined to preliminarily agree with that, as hydraulic pressure should have zero problem to push those stairs down into the slip stream. Need a Boeing parts book for those hydraulic cylinders to see what their specs are. that exist anywhere?

None of this changes the fact Cooper lowered the stairs and bailed during the time period ... the evidence is overwhelming regardless of the mechanics of the stairs. 
« Last Edit: May 03, 2022, 02:10:53 PM by georger »
 

Offline 73blazer

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Re: General Questions About The Case
« Reply #3298 on: May 03, 2022, 02:25:53 PM »
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None of this changes the fact Cooper lowered the stairs and bailed during the time period ... the evidence is overwhelming regardless of the mechanics of the stairs.
Nobody is disputing he lowered the stairs and bailed.  Just questioning if the stairs were actually locked and the viability of a locked staircase bouncing back up.  If the pressure bump was produced by something else, the time of bailing could possibly be completely unknown. How about that rear cabin door leading to the aft stairs, could that create a pressure change reading. Was that door already opened from the ground for the test?  Did the sled test crew have to improvise to put these stairs in a somewhat difficult to attain unlocked position in order to get the stairs to bounce? Is there a light for that rear door on the 2nd officers station  like the airstairs themselves? I'm just curious to dig some more and see exactly how those stairs and door work. I'm also with Edwards on wishing to see the sled test full report and how it was setup.
« Last Edit: May 03, 2022, 02:47:53 PM by 73blazer »
 

Offline Shutter

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Re: General Questions About The Case
« Reply #3299 on: May 04, 2022, 10:43:11 PM »
The stairs were never in a locked position. the crew states this as well as the stairs dragging on the taxi after landing. the stairs would more than likely be damage if in the locked position during a landing. as the plane slowed down on landing the stairs slowly came down and then caused some sparks from hitting pavement.

It's pretty simple. the stairs were engineered to open and close on the ground. they were designed to handle the weight of the stairs and not much more.

You will notice when the stairs were released and when they close. there is nowhere for the air to go since the plane is sealed except for the opening of the stairs.

The first sled test was done with someone on the stairs and Anderson reported the test did not replicate what happened on the night of the hijacking. the second test was done and they used rope to lower the sled down and release sled. Anderson reported that it was "identical" to what happened on the evening of the hijacking.

The first test had someone on the stairs which didn't allow the stairs to retract much. the second test left nothing on the stairs and they were able to retract easier and cause the "violent readings" to occur.

On YouTube type in Boeing 727 rear stairs and a video will show the operation of the stairs, including the lights on the engineers panel.
 
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