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ACEregular
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My Theory On 5B-DBY

Wed Aug 17, 2005 3:01 am

I think the plane suffered a slow decompression, which was occuring not long after take off as the cabin was apparently cool and their were problems with air conditioning. One of the pilots became hypoxic and this will have alerted the other pilot, for some reason the flightdeck oxygen was unservicable and in the effort to leave his seat the remaining pilot passed out and slumped to the floor behind his seat.

The cabin crew would have only been alerted once the cabin altitude passed 14,000ft and the masks automatically deployed, this could have even occured before the pilots passed out I am just speculating. The most important rule for the crew once those masks drop is to get themselves onto the o2 as they will be useless in any eventuality, so they immediately get on o2 and as with my own SOP await instruction from the flightdeck. Normally an immediate descent would take place, the crew know this but realise it is an emergency situation but dont try to make contact with the flightdeck at first as they know the pilots will be busy.So they sit waiting for the descent but its not happening, eventually they go onto their portable set and try to make contact with the flightdeck. The cabin PSU o2 begins to run out as it only lasts long enough to commence a descent to 10,000ft (12-15 mins). the crew realise the predicament and gain entry to the flightdeck as they DO know the combination. To thier horror both the pilots are dead or incapacitated and in the cabin the remaining crew are battling to keep the passengers alive on gasps of air from the small supply of portable o2 which the crew are now on.

The F-16's are scrambled due to lack of communication and see the male FA in the flightdeck (reportedly he was or had trained as a pilot) they also see into the cabin passengers who have already succumbed or passed out. I believe all of the cabin crew at least would have been alive, as they had the portable sets and their training would have meant they knew they were the only one's to help and if they came off them they would be no use. The aircraft I do not believe ran out of fuel though, I think maybe in panic whoever was left trying to save them may have lost control of it or something I cannot even bring myself to say occured.

All in all a sad event and my thoughts to all involved
 
tundra767
Posts: 401
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 4:32 am

I like your theory. Thats sounds very possible. I wounder how long it took the crew to realize something was wrong and call the flight deck? Our crew training is similar that we wait for the airplane to level out then seek further instructions. Its very interesting.
 
backfire
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 4:43 am

If the cabin had been suffering a loss of pressure the pilots would have been alerted.

The drill would then have been to automatically put on oxygen masks before checking the actual cabin pressure or taking any other action.

It sounds more likely that one of the two pilots was in the cabin attending to a minor matter - perhaps a small technical issue or even using the lavatory - and left the co-pilot flying.

A rapid depressurisation would have caught out the pilot in the passenger cabin, and might have overcome the co-pilot - was he practised enough, or experienced enough, to remember the oxygen drill? Who knows?

I suspect the passengers and cabin crew didn't realise that the co-pilot was unconscious. It wouldn't have been obvious if the aircraft was cruising without any difficulty.

Eventually someone would have felt obliged to check the cockpit. While the passengers would have been on the "rubber jungle" oxygen masks, the cabin crew might have had access to portable oxygen, allowing them to move to the front of the aircraft.

All speculation, of course.

[Edited 2005-08-16 21:55:08]
 
ACEregular
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 4:46 am

So they put on their oxygen masks and nothing came out..............................
 
backfire
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 4:57 am

Quoting ACEregular (Reply 3):
So they put on their oxygen masks and nothing came out...

Unlikely. That would mean two independent failures on the same aircraft at the same time. It's highly improbable.
 
qwerty
Posts: 383
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 5:22 am

I don't agree. The current groupthink seems to be the pilots tried to solve an O2 problem by moving around the cabin or cockpit. I don't buy it. Pilot nature is to solve the problem with the flight controls. Fly the plane. Yes, O2 is an important intermediate step in ending a appearant decompression, but altitute is the ultimate solution. They had time to do this. So I remain 100% puzzled as to what exactly happened.

I'm going to speculate the problem was cockpit resource management or disagreement about descending. Probably a residual of a disagreement about going to altitude in the first place after thinking they had an initial problem.

If the autopilots had been changed to 8,000 while pushing the yoke forward even if the crew then passed out due to a true O2 problem (they should have discovered in preflight, so I am dubious of bad/faulty cockpit O2) they would have been fine eventually. Recovery from oxygen starvation is quickly solved when good air is retuned to the system. So even in this worst case, the plane is saved but it would have been a very scary episode. So, I remain 100% puzzled as to exactly what happened. There is too much conflicting information now.

I will say there is probably not one mistake the doomed the fate, but a series of many seemingly small mistakes that eventually cascaded.
 
ACEregular
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 5:43 am

Please do not get me wrong, I am not saying it definately happened this way but from my perception of the situation based on my experience working in the cabin of a 737 and my own SOP knowledge, my mind put together a picture of how the situation could have spiralled from bad to ultimately the worst. I am pretty certain though that not all of the people on board were frozen or incapacitated when it finally went down. Perhaps also my own SOP will change in the case of decompression and a crew member would proceed to the flightdeck on portable oxygen as soon as it becomes clear this has happened.
 
by188b
Posts: 561
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 5:47 am

thats sounds a good theory aceregular, your right about one of the cabin crew, he was a trained pilot aged 25yrs.
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qwerty
Posts: 383
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 6:24 am

Quoting ACEregular (Reply 6):
Please do not get me wrong, I am not saying it definately happened this way but from my perception of the situation based on my experience working in the cabin of a 737 and my own SOP knowledge, my mind put together a picture of how the situation could have spiralled from bad to ultimately the worst.

Great comment. Question for you, would you get out of your seat? I sure wouldn't until I knew the plane would eventual find good air.

Again, I think the only reason a captain would be out of his seat would be because someone moved him to revive or get out of the way. This might be a possibility given the 25-year old male cabin crew.

I mentioned this in the 3-part other thread without any comments. What puzzled me is, if the F16 reports are true of people moving in the cockpit, why did these people not make any gestures to the F16s. Maybe they did, but I would think those details would be passed along in F16 details since this activity would be the paramount thing remembered. Clearly both parties could see each other easily and it's human nature to look around in crisis. So, I am sure they would look out the cockpit windows to at least orientate.
 
tundra767
Posts: 401
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 6:30 am

Quoting Qwerty (Reply 5):
I will say there is probably not one mistake the doomed the fate, but a series of many seemingly small mistakes that eventually cascaded.

This is very true. I am still with the theory of a slow pressure decompression. Then the captain may have left the cockpit to investigate the problem, perhaps a leak or something. Then with all of the physical exertion of getting out of his seat and what not passed out. What I am not sure of and procedure may vary but why did the f/o not have his mask on with the capt. out of the f/d? My bet is complacency we all do it.
 
RobertS975
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 6:46 am

All speculation, but the pilot may have been simply out of his seat and hanging out in the forward galley when the decompression occurred. Many Americans are surprised to learn that the understandably rigid concepts of cockpit security to which we have become accustomed are not routinely practiced aboard many foreign carriers.

The pax have a very limited supply of oxygen from the O2 generators. Any FA that tried to assist in the cockpit had to have a portable tank, but even then, the delivered O2 is not under pressure, and even minimal exertion will be difficult.

So my theory is simple... decompression occurred with the pilot out of his seat, the co-pilot either tried to troubleshoot before donning his mask or the mask/O2 delivery system was faulty. This lead to an unconscious Captain out of the cockpit and an unconscious co-pilot at his station.

The CVR is a 30 minute loop in most instances, and since the plane flew without ATC contact for longer than that, I doubt there will be any useful info on the CVR. Perhaps some of the FA's apparent attempt to regain control may be documented on the CVR.
 
UAalltheway
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 6:48 am

Quoting RobertS975 (Reply 10):
So my theory is simple... decompression occurred with the pilot out of his seat, the co-pilot either tried to troubleshoot before donning his mask or the mask/O2 delivery system was faulty. This lead to an unconscious Captain out of the cockpit and an unconscious co-pilot at his station.

Because of their altitude they most likely froze almost instantly..
 
qwerty
Posts: 383
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 6:53 am

Quoting UAalltheway (Reply 11):
Because of their altitude they most likely froze almost instantly..

B.S. In the fight of metabolism and body temperature versus -58 degrees, instantly is not the adverb I would use.

Coldness is an ancillary issue for this incident.
 
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garpd
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 7:13 am

Quoting UAalltheway (Reply 11):
Because of their altitude they most likely froze almost instantly..

Well if it was cold enough to freeze pax "instantly" why were some still alive upon impact?

The very fact some pax and crew appear to have been living and breathing when the plane smacked into the hillside pours a lot of cold water over the decompression and running out of oxygen theories. While its possible decompression happened to a certain degree I do not believe it was total and probably not the sole cause of this tragedy.

The question I'd love to see answered is how some "froze" and others did not?

How is it the pilot was observed slumped over the controls on the first intercept and 20 or so minutes later people were found moving?

If the O2 had indeed ran out as some theorise, it must have happened before the first intercept. But throwing a spanner in that theory is the possible sighting of people moving in the cockpit and a coroner telling use some were alive on impact. How were they alive? If no oxygen existed, you have 5 to 10 minutes max before you're dead. Only 2 or 3 minutes of consciousness at that.

I find it unlikely portable O2 bottles could have lasted from the time of "oxygen removal" to the impact which is a good 40 minutes at least.

Then there is the question of where the Captain was.
I do not believe for one moment the commander of a commercial aircraft would get up out of his seat if in the middle of a situation such as depressurisation.
This contradict the years or training and recurrent training a pilot goes through during his career.

Nothing adds up!

[Edited 2005-08-17 00:16:44]

[Edited 2005-08-17 00:21:46]

[Edited 2005-08-17 00:23:04]
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ACEregular
Topic Author
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 7:31 am

As Crew you do what you can, thats all I can say, am sure they did until they couldnt do it any more
 
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garpd
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 7:33 am

Quoting ACEregular (Reply 14):
As Crew you do what you can, thats all I can say, am sure they did until they couldnt do it any more

I don't doubt that for a second. It was not my intention to question the crew in anyway.

I was merely showing my doubt on some of these complete decompression and o2 running out theories.
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tundra767
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 8:04 am

This is going to be a very interesting couple of months until we find out what really happens. I am very anxious to hear what the CVR will have to say.
 
wukka
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 8:28 am

Quoting Tundra767 (Reply 16):
I am very anxious to hear what the CVR will have to say.

Definitely... unfortunately I just read that one of the investigators said that the CVR had discharged its contents from the actual container, so there may be unrecoverable damage to the recordings -- solid-state or not.  Sad

If they can get anything out of it, though, it might give some much needed insight into the huge mystery of contradicting reports.
We can agree to disagree.
 
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garpd
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 8:36 am

Quoting Tundra767 (Reply 16):
This is going to be a very interesting couple of months until we find out what really happens. I am very anxious to hear what the CVR will have to say.

Assuming the investigators can extract into from the CVR, it will only be from the last 30 minutes.

As the "knock out" incident occured at the very least 120 mins prior to impact, any info will have been lost due to the CVR re recording over the top of it. Mores the pity  Sad

I think the FDR which I beleive records far more data for a longer period will most likely reveal the details to this mystery.
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AMSSFO
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 10:33 am

Quoting GARPD (Reply 13):

Well if it was cold enough to freeze pax "instantly" why were some still alive upon impact?

The very fact some pax and crew appear to have been living and breathing

"Alive" as according to the coroner doesn't mean conscious; it simply means that the heart was beating at the moment of impact, nothing more, nothing less. People might well have been brain-dead already, as the brain succumbes as first; it's the organ that needs most of the oxygen present in blood.

Different bodies react differently to exposure to cold (fat or skinny, you get the picture). It also depends on what cloths someone wears; whether they are sleeping under a blanket etc. Some bodies may have been frozen and other may not.

Agreed it is an mysterious accident.
 
B744F
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 10:36 am

i don't get it why people would think the pilots would try to solve a problem BEFORE trying to descend... this makes no sense... first you get the aircraft lower, THEN you try to figure out what's wrong.
 
Sasha
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 10:43 am

Having experienced -58C and lower myself on regular basis (winters in Far East Russia, eh... ) I can say that someone subjected to that temperature, wearing summer outfit can usefully operate for around 10-15 mins. No longer. But no less. We frequently used to run out outside just in shirts, etc at school when it was that cold outside, during a class break, which is 10 mins. All the steel surfaces (door handles, knobs, etc) become extermely painful to touch and grab...

Given the supposed fact that there were people in the cockpit .. could it be that the extreme freeze affected the fuselage partially, leaving some parts free of -58C?
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RobertS975
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 11:58 am

Quoting B744F (Reply 20):
don't get it why people would think the pilots would try to solve a problem BEFORE trying to descend... this makes no sense... first you get the aircraft lower, THEN you try to figure out what's wrong

Because the true nature of the emergency is often not clear immediately at the outset. Once the situation progressed to decompression, there were only seconds to reach for and wear the O2 masks in the cockpit. And no time to make sure that the valves were "on" and the hoses not kinked or pinched.

This type of accident, which we presume was due to an unconscious cockpit crew in a depressurirsed aircraft, is something that happens periodically... Payne Stewart and the Lear 35.... then there was an aircraft carrying an American college football or basketball coach that flew out over the Atlantic on autopilot and crashed.

It does not appear that the Captain was in the cockpit at the time of the crash. We do not know what to make of this. Was he hanging out in the forward galley on a routine flight? Was he back troubleshooting something?

IMO, a Captain would not leave the cockpit if something were wrong, so most likely, whatever occurred happened suddenly.
 
md80fanatic
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 12:16 pm

The bleed air from the engines is still being pumped into the craft even with air leaking out. The hole would need to be pretty big to overwhelm the engine bleed air, resulting in a net pressure release. If it were a small hole leaking little air the pressure rate could be increased, probably automagically from the cockpit. If they were losing air faster than it can be replentished...there is nothing the captain could ever do about it (other than fly the aircraft).

The previous posters are right....there is now too much conflicting information (I believe on purpose) to come to any sort of viable conclusion.
 
hmflyer
Posts: 73
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RE: My Theory On 5B-DBY

Wed Aug 17, 2005 11:44 pm

Here is my theory. The Captain left the cockpit, perhaps to use the restroom. While he was gone, there was some kind of rapid decompression. The FO did not have on his 02 mask as per most airline's SOP. Could not get his mask on in time to keep conscious, or the O2 mask did not work properly. Perhaps the person is the cockpit was the Male F/A who probably had a portable O2 bottle. That is my 2 cents.

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