DB Cooper

[Farflung 0]

From 377’s post from another website is:

“The interesting part is this. World Airways had only six 727-173Cs.
Their manual says they kept them all the same. They flew some contract
work in SE Asia during the Vietnam war. They likely bought the 727s for
this, and likely even with the money they got from those contracts.
Maybe they actually put the flow restrictors in their planes to keep the
stairs from rebounding when something or someone went off the end of the
stairs during flight?”

After some plausible technical analysis, the ‘Special Ops of Vietnam’ (aka Frankenstein) was introduced again. Here’s a video of the ‘Black 727’s’ which was posted earlier:

http://www.youtube.com/watch?v=lrqdmXxBZjI

The salient parts are (1:20 – 2:12). Where are the stairs for cargo drops and personnel jumps? Where is there any photo or source of a non-hijacker or non-FBI/USAF (after Cooper) using the aft stairs to jump or do a cargo drop from a 727 or DC-9? Was this a leap in logic/faith?

I could be wrong here (oh dear) but the valve schematic makes the ‘restrictor’ function appear to be more of a fluid shunt as a way to limit the force applied when the handle is in the ‘DOWN’ position. Don’t think the engineers would want to design an accidental tail jack or in Cooper’s case a down elevator in the aft fuselage. Source please.

[377 22]

Farflung,

The analysis of the stair operation wasnt mine, I just reposted naturehominid's post from the DB Cooper Reserach Group (on Yahoo Groups). Here is the next one he made:

Quote

Re: Used "Emergency" Means to Drop the Airstair
Posted by: "naturehominid" Mon Sep 19, 2011 5:44 pm (PDT)


You (loyal readers;-) may have noticed that I did not mention in the preceding post that one of the "givens" is that the amber AFT AIRSTAIR light on the flight engineer's (FE's) panel (2nd from top of first column, just below the AFT ENTRY light) had been on for a while. I didn't address it because it turns out not to matter.

(BTW: If you're looking at an annunciator panel with a green AFT AIRSTAIR light, or with an AFT AIRSTAIR light fourth down from the top in either the first or second column, you're looking at a panel in a -200 series 727. N467US was not like this.)

The first thing that happens to make the FE's AFT AIRSTAIR light come on is moving the airstair control handle out of the UP detent. If Dan moved the handle barely out of the detent, the latches would not have released the stairs and the control valve would not have moved out of the UP state or into the DOWN state. The handle could have been moved right back into the detent and everything would have been the same as when the stairs had last been stowed (up).

If Dan had moved the handle all the way to DOWN, the latches would have been fully open and the control valve would have changed to the DOWN state as shown in the diagram of BOEING 377's manual. If the stairs did not drop, the handle could be moved all the way back to the UP detent (or near it) and the control valve would have changed back to the UP state. (Had the stairs dropped some, a device associated with the UP stop on the right side of the stair opening would have prevented the handle from moving all the way back to the UP detent position.)

So there were multiple ways the control valve could have ended up in the UP state (condition necessary to have freefall AND rebound) even though the AFT AIRSTAIR light was on at the FE's annunciator panel.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[377 22]

Quote

After some plausible technical analysis, the ‘Special Ops of Vietnam’ (aka Frankenstein) was introduced again. Here’s a video of the ‘Black 727’s’ which was posted earlier:

http://www.youtube.com/watch?v=lrqdmXxBZjI

I've seen no photos of 727 airdrops with the stairs deployed other than the FBI flight test with the "sled". The DC 9 I jumped had the stairs removed and a steel slide installed to make a mass serial exit easy. The slide extended only to the edge of the fuselage and did not protrude into the airstream.

In the Air America/Southern Air video above, I liked seeing an old Beech 18 flying in tight formation with a 727. That Beech must have been firewalled and the 727 just above Vmc.

I jumped from many Beech 18s. I watched the late Mike Rust do a full Bob Hoover type aerobatics demo in a Beech 18, which was amazing. He even did a low slow roll with one engine feathered.

Farflung, don't kill our fantasy that Cooper was a Nam vet special ops bourbon drinking HALO qualified badass, with a grudge and knowledge that a 727 was indeed jumpable.

We want him to be James Bond, not Duane Weber.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[Farflung 0]

The conclusion from naturehominid:

“The only stair deployment method that fits what we've been told about
the hijacking is the emergency extension method with the normal stair
control handle left in the UP position.”

Just a few gaps to fill in here, strictly administrative stuff and boring enough to put a Clydesdale to sleep.

1. Handel was left in ‘UP’ position? Source please.

2. Only stair deployment method (Emergency)? Why not electro-mechanical AND/OR pneumatics? Source please.

3. Emergency Extension was used? Mechanics logs should indicate recharging the bottle. Source please.

4. Emergency Extension ‘knocks off’ the up locks? Source please.

I have not known that the aft bottle was blown and am either smarter, more confused or have another bowl of steaming ‘known facts’ about DB Cooper sitting in front of me. But would not want to add to the noise and will accept the above at face value.

Everything is Hollywood, with Special Ops Cooper ‘Blowing the Hatch’ and the violent rush of air forcing Tina’s skirt up as she clings to a seatback while the turbulence shakes and jiggles her entire body until her childhood photo is knocked loose which floats, a la ‘Forest Gump’ into Cooper’s money bag upon which he lights a flare that hypnotizes Tina and makes her forget the toupee wearing employee she met at an Airstream dealership in Seattle and mistakes the brilliant light as a higher calling and quickly resigns from Northwest and never reports her missing photo which is proof that she fears for her life. Yep.

[georger 244]

CONCLUSION

The only stair deployment method that fits what we've been told about
the hijacking is the emergency extension method with the normal stair
control handle left in the UP position. Besides detaching the uplock
rollers, this would have damaged the latches.

377

[Robert99 50]

Quote

CONCLUSION

The only stair deployment method that fits what we've been told about
the hijacking is the emergency extension method with the normal stair
control handle left in the UP position. Besides detaching the uplock
rollers, this would have damaged the latches.

377

If I interpret this correctly one result would be
far more communication and direct action (by some
means) between Cooper and the cockpit possibly
thru Tina? None of this interplay is made explicit in
the transcripts. Gray's book develops some of it -

We know he got out of the plane, by some means.
We also know a reporter on the scene at Reno
reported 'some damage' to the air stairs after
landing - whether this damage is consistent with
Homonid's speculation is uncertain ?

Does it follow, that getting the door open and stairs
down relied more on the crew than on Cooper or
Cooper's knowledge or skills personally than
previously thought - because we know Cooper had
trouble and we now know crew intervention was
required. ?

[Orange1 0]

This might be a dumb observation ...but 377's posting of the analysis just seems...well, too analytical for the circumstances. Remember we are talking a bunch of people who - Cooper aside - didn't even know you could lower the stairs in flight. I'm not convinced at all they would have gone through the thought processes outlined? Occam would say that however the stairs were lowered, it wasn't done as a result of thinking through it all like that, surely?

Skydiving: wasting fossil fuels just for fun.

[Robert99 50]

Quote

This might be a dumb observation ...but 377's posting of the analysis just seems...well, too analytical for the circumstances. Remember we are talking a bunch of people who - Cooper aside - didn't even know you could lower the stairs in flight. I'm not convinced at all they would have gone through the thought processes outlined? Occam would say that however the stairs were lowered, it wasn't done as a result of thinking through it all like that, surely?

Orange, I think you and Occam are both right on this point.

[pek771 0]

This is a very interesting analysis done by naturehominid. One question I have had, which really would tell a lot about the DB Cooper story is this: Where did the ground crew in Reno find the levers? They could have definitely told how the stairs were placed down. I have not seen this information anywhere. I suspect the FBI knew it was done via emergency extension, else why would they have conducted the drop tests? From the diagram I have, it appears that the shear lugs in detail "D" would have sheared, which makes sense....you wouldn't want the stairs to go back up during an emergency egress. If the stairs were used in normal DOWN, then they should have been locked, as, if I recall, the stairs were also used as an aft support to keep the nose gear on the ground during ground operations. Thus, we have an implication that the crew did indeed disable the B hydraulic system, for their own safety. Was this ever mentioned publicly?

The basis of the assumed drop zone is based strictly on the perception that the "pressure bump" was in fact Cooper leaving the stairs.

[georger 244]

Quote

This might be a dumb observation ...but 377's posting of the analysis just seems...well, too analytical for the circumstances. Remember we are talking a bunch of people who - Cooper aside - didn't even know you could lower the stairs in flight. I'm not convinced at all they would have gone through the thought processes outlined? Occam would say that however the stairs were lowered, it wasn't done as a result of thinking through it all like that, surely?

Great question
Equally dumb question: Why have we always taken
for granted the crew 'didnt' think the stairs could be
lowered in flight. Just because they got advice and
had never taken off with the stairs down or opened
them in flight doesnt mean they didnt assume it
could be done by some means, or in some cases
even happened on its own based on prior reports ?

My bias is: they thought the stairs could be opened
in flight - they didnt know how so got advice. They
thought the stairs needed to be up to take off but
just had never faced the stairs not being up on
takeoff before ... thus got advice.

Because as a matter of fact we know there were
instances of these stairs coming open on their own,
if I remember past posts on this topic ??

What am I missing?

Sorry to complicate things...

[Farflung 0]

Separated redundancy and ‘B’ hydraulics and/or stabilized 28 volt juice.

The aft stairs are driven by an electric motor and hydraulic pump which moves the actuators in one of two possible directions. This is for ‘normal’, ‘vanilla’, ‘gee life is great’ days at work.

The choice for the stair operator or hijacker is the mystic ‘UP’ or ‘DOWN’ and nothing more. Which way do you want the stairs to go? That is all. On a normal day the stairs would gently fall in the direction of gravity and stop when hitting the ground.

Now for when you are not having a ‘gee life sure is great’ day:

First you would move the handle to the position you want the stairs to go and that choice would be the one the handle is NOT in when you make that ‘decision’. You see there really isn’t two positions for the handle, rather just the one you must want since you are playing with the aft stairs. Move the handle to the other position and forget about all this reading which will confuse and frighten a hijacker.

Nothing Happens.

There is a handle you can rock fore and aft to assist the stairs ‘DOWN’ if there is an electrical failure and the ‘B’ hydraulics are not present. According to the manual you will need to give it approximately 68 pumps to raise the stairs. Anyone familiar with airframe systems knows about the manual jacks for stairs, cargo doors and landing gear. If Cooper was laden with flight experience he surely would have been giving the old Johnson a few strokes before resorting to any Emergency Procedures (force of habit).

Still Nothing Happens.

This typically occurs in downtown ‘Ahhshit’ when the final arrow in your stair lowering quiver is removed. This autonomous system has a tank of nitrogen (nitro if you want to impress the ladies) which is charged to a ton of pressure and will open the stairs in a similar way to the hydraulic system. It does not explode open but if it makes you happy, by all means imagine this to be the case. There are some ‘shear lugs’ which will be sacrificed during this operation but that assumes you have moved the handle back to ‘UP’ and you are in fact a moron. Gosh Wally, I’ve already got an emergency situation on my hands; should I move the handle from ‘DOWN’ back to ‘UP’?

The analysis took some liberties with information like the lugs being sheared, the nitrogen tank being drained and the handle being in the ‘UP’ detent upon landing in Reno. This is all news to me and I anxiously await the sound of cricket chirps before NOT receiving any source attribution again.

[Orange1 0]

Quote

[Equally dumb question: Why have we always taken
for granted the crew 'didnt' think the stairs could be
lowered in flight. Just because they got advice and
had never taken off with the stairs down or opened
them in flight doesnt mean they didnt assume it
could be done by some means, or in some cases
even happened on its own based on prior reports ?

My bias is: they thought the stairs could be opened
in flight - they didnt know how so got advice. They
thought the stairs needed to be up to take off but
just had never faced the stairs not being up on
takeoff before ... thus got advice.

Because as a matter of fact we know there were
instances of these stairs coming open on their own,
if I remember past posts on this topic ??

What am I missing?

Sorry to complicate things...

Georger - I don't have the transcripts anymore but I clearly remember a lot of to-ing and fro-ing between the cockpit and NWA because not only did they not know the stairs could be lowered in flight, they believed it might be dangerous. Maybe someone who still has the transcripts (and the time, which right now is rather a scarce commodity on my part) would like to go through them to find the exact conversations.

Skydiving: wasting fossil fuels just for fun.

[377 22]

I am liking this. Toss a little bit of 727-1** systems manual and Monday morning engineering into our forum and tempers calm down, Clydesdales go back to the barn and we ponder Cooper related facts rather than attacking each other.

I like reading aircraft manuals. It has a calming effect as I try to figure out the complex systems.
My favorite is the Convair B 36H. Six 28 cylinder radial engines and four turbojets. Endless dials, gauges, switches and levers.

http://en.wikipedia.org/wiki/Convair_B-36

and check out its cargo carrying prototype, the XC 99

http://en.wikipedia.org/wiki/Convair_XC-99

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[pek771 0]

I may be missing a page from the schematics, but where is the electric motor? It seems we can only lower the stairs by hydraulic pressure, nitrogen pressure or gravity.

One other little thing about the mysterious yet entertaining stairs. There are two separate control locations for the stairs; top of the stairs and outside under the (starboard?) engine. Do they have to be lever-positionally coordinated by the ground crew? ie, is it like a room with two light switches for the same light? This may be a stupid statement at this moment, but what I do have for schematics, I left at work.

[Farflung 0]

Here you go pek771,

I must have had another dumb attack by not posting a source (see attach).

The ‘A’ and ‘B’ system is brilliantly separated by using two differing sources of drive for the hydraulic pump. That is engines and aircraft electric which takes advantage of the differing power sources thus separating a failure in one. Obviously an electric source would be needed for the most dire of civil jet failures which would be a ‘dead stick’ landing from some catastrophic failure or fuel starvation.

The ‘B’ system is driven by electric motors and further upstream than the diagrams which 377 had posted. None the less, the hydraulics are a study in how the separated redundancy is designed into aircraft.

The aft stairs had hydraulics which were powered by an electric motor but were likely used only to raise the stairs. Then is the manual pump (jack and Johnson bar). Last is energizing the nitro (easy ladies, easy) tank.

As far as the handles (see 2nd attach) with my monkey X-Ray (but can’t see people on the aft stairs in flight) eyes, there appears to be an interlocking device that moves the handles together. That’s all I got.

[georger 244]

Georger - I don't have the transcripts anymore but I clearly remember a lot of to-ing and fro-ing between the cockpit and NWA because not only did they not know the stairs could be lowered in flight, they believed it might be dangerous. Maybe someone who still has the transcripts (and the time, which right now is rather a scarce commodity on my part) would like to go through them to find the exact conversations.

[377 22]

That "pump it" poster is classic Farflung. The USAF should have had you editing the Dash One manuals. Those system schematics would have received far greater attention had you been given editorial command.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[Mr.Green 0]

Quote

The PDF to Blast has been made available to the FBI, to reporters, to TV guys, etc. So this is not a real big deal, but if you'd like to have a copy (its an exact rendition of the interior of the book, including the pictures) you have until Wednesday night, 8PM Seattle time to download it from our DB Cooper page at AB.

The easiest way is to right-click on the link at the AB page and do 'Save Target As', then save it to a folder on your computer. A couple of the pictures look a little strange, but none of the important ones. That's because the actual print file ran nearly 35mb and this PDF is in Standard Resolution for emailing purposes and goes maybe 3mb I think. Gayla Prociv says I can leave up the link until Wednesday. It's mostly a question of bandwidth. The file is being heavily downloaded.

Here's something: If you are going to complain about the book, you should at least see it first. (*smiles*)

Yes, that was a joke.

EDIT: I attached a picture of Gayla and I working out details on something or other. You wish YOUR woman looked this good at age 52. And other things that I won't discuss here. Pic is from 2008 I think. Although I have the last word on content, she has the last word on policy.

Thanks for the download Blevins

[skyjack71 0]

Has taken me 2 days to get back. I learned a lot about how to get back if I ever screw up the proxy again - but I think I will sleep for the next 10 hrs.

Really think you guys are over working the aft stairs - it was NOT as complicated as you think. I understand that NOT all of the planes had an Aft way they had to control from the pilots arena. There was a light that let them know it was up and locked in place or if it was down.

Bill'S wife and himself are struggling right now to enjoy their life or I would contact him. You guys are really trying to complicate this effort regarding the Aft way.

You guy are really going to hate me in NOV. But I figure what the hell do I have to loose. The world already thinks I am a crazy loo loo who was out for 15 minutes of fame. If that was true then why have I hidden behind a thread? Hoping my health holds long enough for me to finish my project. I has to be done RIGHT or NOT at all.

Just wish I had enough money to do it right - but my poor folks way will have to do. All it is going to SHAKE UP the FBI and cause them to SCRAMBLE. Well, they could have been incontact with me and have really have studied the information I have acquired these last few yrs. That has been their choice.

Right now trying to find as many front pages as we can run this on and as many programs - all of this have to hit at the same time.

WAS DUANE REALLY DISLUSIONAL DURING THOSE LAST FEW DAY HE LIVED? SORRY, 377. AFRAID YOU WILL HAVE TO SETTLE FOR COOPER BUT I SUPPOSE THE AUTHORITIES COULD HAVE HAD HIM STRIPING PLANES IN TX AND ARIZONEL....ALL THEY HAD TO DO WAS look! RIGHT there in TX they were stipping planes...to make moves carring equipent and men for secret missions.

Duane did NOT have to be jumper - just part of what was going on and enough guts or fear to go thur with it. If you have already recieved a death notice - the choice is pretty easy.

Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012 2013, 2014, 2015 by Jo Weber

[pek771 0]

Thanks for the explanation. My knowledge of civilian aircraft is lacking a bit. It seems the interlocks are, I am going to guess, via cable.

To the point of egress...I suppose if you want to go "down", you push the down lever. The lever pusher does not care how the hell the stairs go down, that was Boeing's area of expertise.

I still want to know what the ground crew found in Reno. Then again, since there was one hijacking every 5.6 days during the 69-73 or so time frame, maybe post flight inspection wasn't a big deal.

[377 22]

I have found an additional diagram showing the emergency pneumatic blow down system for the 727-172 airstair. I've added it to the site below. It shows up as giant sized but if you click on the image you'll get a readable format.

see: https://sites.google.com/site/boeing727172airstairs/

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[georger 244]

I still want to know what the ground crew found in Reno. Then again, since there was one hijacking every 5.6 days during the 69-73 or so time frame, maybe post flight inspection wasn't a big deal.

[377 22]

Quote

If the stairs
slammed shut creating the pressure spike, how do
they get back down as per the landing at Reno?

Good question. Is it possible that their extension angle was determined by airspeed? When the plane came to a halt on the ground they had no slipstream pushing them upwards.

In the FBI sled test photos (taken from the chase aircraft) the unloaded and loaded stair deflection angles should be visible. I sure wish Ckret had been able to post the video of the sled test.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[pek771 0]

Quote

Quote

If the stairs
slammed shut creating the pressure spike, how do
they get back down as per the landing at Reno?

Good question. Is it possible that their extension angle was determined by airspeed? When the plane came to a halt on the ground they had no slipstream pushing them upwards.

In the FBI sled test photos (taken from the chase aircraft) the unloaded and loaded stair deflection angles should be visible. I sure wish Ckret had been able to post the video of the sled test.

377

If airspeed is the determining factor of stair position (relative to up or down), who is to say Cooper didn't jump when N467 was on approach to Reno? Lower airspeed would have lessened the possibility of a pressure bump.

But, then there is that money thing in the river...

[skyjack71 0]

Quote

Quote

If the stairs
slammed shut creating the pressure spike, how do
they get back down as per the landing at Reno?

Good question. Is it possible that their extension angle was determined by airspeed? When the plane came to a halt on the ground they had no slipstream pushing them upwards.

In the FBI sled test photos (taken from the chase aircraft) the unloaded and loaded stair deflection angles should be visible. I sure wish Ckret had been able to post the video of the sled test.

377

What is available of the sled test was in one of the old old documentaries. I doubt Carr had additional tapes or film of that.

You guys are sure creating some myths lately. Not all of these Boeing were equip in the same way. Why don't one of you BRAVE souls who wants to REALLY know the truth - contact the only man alive who can tell you the truth about that aft stairway on that particular plane.

Only the speed of the plane and the rebound after Cooper jumped - the stairway was particially open till they got to Reno and then when the planes speed slowed down the aft stair drop and that is how the damage happened the aft door way - it was NOT major damage.

Do all the research you want and create all of the myths you want, but you guys are deliberately for some reason over thinking and over researching this aft stairway. Yes, there was a way to lock it down - but Cooper did NOT lock it down nor did the crew!

Instead of intervening in the co-pilot's life at this time - WRITE a letter and give him your phone number and REAL name along with verifiable information about yourself. He just might call you back - when he is not bogged down with private issues. He is a very very nice man and extremely polite, but do NOT get him upset the way XXXX did...by calling him repeatedly and slipping around in his area with a conspiracy theorist.

All of that slipping around cost a certain writer an interview with the co-pilot - your's truely (Jo Weber) was chosen to give the writer a message "Tell him NOT to call me again".

I don't know all of the technical stuff and do not know enough about it to even ask the co-pilot about this. If any of you are interested enough in contacting him - write the letter and I will send it to him...if you are NOT BRAVE enough to do it yourself.
In other words - all of this research is absolutely worthless unless he verifies it.

Considering his circumstances - a letter is the best and most unobtrusive way to go...and the most likely to receive a response.

Getting old - what is the rule about I before E?


P.S. Blevins I just read the post you made while I was doing this one - and you definitely did an interview with the Co-pilot. I do not know what you put in your book, but I do know some of the things others have claimed after they supposedly interviewed the co-pilot. Your statement is exactly the same kind of simple answers he has always provided.

I have a feeling when the technical questions are asked by a pilot and someone very very experienced with the Boeings - he might remember some other little detail. The answers are going to depend on the knowledge of the person asking the question...amazing what one can remember when a trigger is pulled.

Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012 2013, 2014, 2015 by Jo Weber