[disregard]

Edited January 26, 201214 yr by RipaJet

According to wiki:Families of the dead filed a lawsuit against Boeing on 24 July 2007. Their lawyer, Constantinos Droungas, said "Boeing put the same alarm in place for two different types of dysfunction. One was a minor fault, but the other - the loss of oxygen in the cockpit - is extremely important". He also said that similar problems had been encountered before on Boeings in Ireland and Norway. The families are claiming 76 million euros in compensation from Boeing.[30]In the 737-800 have the alarms changed?

The aural warnings are still the same for Take off warning and Cabin altitude warning, but new aircraft are fitted with red warning lights on the captains and f/o's instrument panels to show which warning it is. Older aircraft can be modified to have these lights fitted but don't think it's mandatory (yet).

Why would you ever want the switch to be in manual mode while flying? Shouldn't the plane have a fail safe system so it automatically turns it on or switches it to "auto"?

Why would you ever want the switch to be in manual mode while flying? Shouldn't the plane have a fail safe system so it automatically turns it on or switches it to "auto"?

I think the same applies for many other buttons or switches. Guess that's why the checklists are for.You cannot blaim the machine for an operator's failure!

Would be good if all essential check-list items would be on the annunciator panel as well. If on recall (during pre taxi check) the FO's annunciator would say 'press man' this would have never happened.

Edited January 26, 201214 yr by koyaan

How much of a responsibility is this switch to the engineer vs the pilot? It seems like it could be easily overlooked.

In my line we do not put switches back to where we found them unless the job instructions say so. When doing certain types of maintenance on the ground, we place this pressurisation switch to either manual, or more so "no-press" to prevent inadvertent pressurisation of the aircraft while on the ground if there is a fault in the pressurisation system. The type of maintenance I refer to is anything to do with bleed air.Manual control mode is used obviously if the automatic system has failed.We also know that one of the items in the pre take-off checklist is to check the switch position and another item in the after take-off check list is to check whether the cabin is pressurising or not. If this is not happening, the pilots consult their version of the Quick reference handbook for the drills to alleviate this issue.If it is ignored, our aircraft do have a warning "CAB ALT HIGH" which in their QRH has drills as well. This comes on if the cabin altitude exceeds 10,000ft.We also have the option to put the pressurisation in other modes such as "Const Alt" and one or two others. The pilot determines which one he/she needs to use. One of the the reasons we do not place the switch back to auto.As for the effects of hypoxia, if you haven't experienced it then you will not recognise it. As simple as that. It is like being drunk to easily describe it, and when the altitude decreases you just don't get normal concentrations of oxygen and wake up and be as normal like on the Tv shows. You get the "hangover" bit as well. Which is probably why no one, even though conscious were capable of anything sensible.It's a shame...Rest their souls, and hopefully everyone responsible has learned something from this

Edited January 26, 201214 yr by Richiebacardi

As the cabin altitude increased above 14,000' the oxygen masks in the passenger cabin would have automatically deployed. Any passenger who had paid attention to the safety briefing would have placed the mask over their nose and mouth, adjusted the strap and breathed normally... and then spent the 30 or so minutes of oxygen that system can supply wondering what the hell was going on....

Yes sure, but that doesn't explain why those people survived the rest of the flight until it fianlly crahsed. In the theory lessons for my PPL I've been told that you can't survive in that altitude from about 8000m you'll die very fast!!! So why didn't those onboard the flight die from that?

RW I use manual mode quite often. In cold weather operations, you close the outflow valve so the water service in the aft lavatories doesn't freeze. That's on the ground, of course. We close it to about 90%, but I don't know if that would be good enough to prussurize the plane out of 10,000' or not. I imagine it would.

Yes sure, but that doesn't explain why those people survived the rest of the flight until it fianlly crahsed. In the theory lessons for my PPL I've been told that you can't survive in that altitude from about 8000m you'll die very fast!!! So why didn't those onboard the flight die from that?

they did die from lack of oxygen the only person who lasted and that was seen in the cockpit by the 2 f-16s was one of the cabin crew who was using the spare oxy bottles to work hes way to the cockpit where he found the 2 pilots without there oxy mask on. On further investigation they found out that the cabin fligtht attendant tried to put on the mask on the pilot but was unable to revive the pilot.

 

Kriva, are you a real world 737 pilot?

Sadly, I'm not, at least not yet... Just a Cabin Crew Member with a lot of (close to unhealthy) interest for the planes I fly in.

Edited January 26, 201214 yr by KriVa

It also should be noted that once inflicted with hypoxia, if you're still awake, your decision making capabilities aren't good. Simple tasks are impossible and confusion takes over.... So radioing back to the engineer to figure out what is going on, when the "fix" or checks should be pretty obvious to a capable pilot.... makes complete sense.

On a semi-related note, any chance of the CABIN ALTITUDE/TAKEOFF CONFIG lights be implemented in SP1c or SP2?

[...] and hearing what you real pilots had to say [...]

Just to make clear, I'm not a pilot. Not even a Private Pilot. I intend to follow the commercial pilot carrer one day, but until this point I'm simply a just-graduated 11th grade student.

You cannot blaim the machine for an operator's failure!

Exactly. The aircraft doesn't need necessarily to make things the easiest possible for the pilots. It's nice when they do so, but it's not mandatory in the airline industry. This switch (as many other systems) has a MANUAL position to allow pilots to intervene in situations where the pressurization system is behaving incorrectly or fails completely. It's for security reasons. But still, it is the pilot's responsability to check the correct positioning of switches and knobs as well as monitor the behavior of systems even when they are working automatically and good alert devices are provided.

It also should be noted that once inflicted with hypoxia, if you're still awake, your decision making capabilities aren't good. Simple tasks are impossible and confusion takes over.... So radioing back to the engineer to figure out what is going on, when the "fix" or checks should be pretty obvious to a capable pilot.... makes complete sense.

That's right. Hypoxia don't kill right away. It's not like a shot in your brain. It's a slow and unoticiable process. Brain cells, as well as almost every cell in you body needs oxygen. That's what provide the cells energy to keep working. When you deprive a cell or tissue of oxygen, it starts losing 'performance'. It's like us humans. If we don't eat enough, we start getting weaker and weaker until we pass away due to lack of enough energy to keep the vital body systems working at a minimum pace. That's what happens to your brain cells. They start losing strengh and ever less electromagnetic impulses are transmitted between neurons. We all know electromagnetic impulses along with some chemicals are what constitute our memory, thinking and what transmits commands to the rest of the body via the nerves. So with less of them, we start not beeing able to remember what we've learned, take much more time to take decisions and move slower. Neurologists estimate that we forget about 75%, maybe more, of what we learned if prolongedly exposing the brain to low oxygenation situations.

Edited January 26, 201214 yr by barfra1995

Would be good if all essential check-list items would be on the annunciator panel as well. If on recall (during pre taxi check) the FO's annunciator would say 'press man' this would have never happened.

That is one of the best features of EICAS systems. If this were to happen on an EICAS equipped airplane, most likely this would happen, apart from what already did:-"MAN PRESSURISATION" caution or advisory would likely be annunciated, even pre-flight.-"CABIN ALT" warning (presumably, possibly caution) would illuminate with the horn-Bleed air and/or pressurisation system synoptic page would likely pop-up on lower EICAS DU, depending on specific systemAs you know, the NG does not have the EICAS system fitted for historical/commoniality reasons, although this was a Classic variant anyway. Moreover, since the pilots were probably already suffering from effects of hypoxia at this point, so even EICAS might not yield better resolution.

That's right. Hypoxia don't kill right away. It's not like a shot in your brain. It's a slow and unoticiable process. Brain cells, as well as almost every cell in you body needs oxygen. That's what provide the cells energy to keep working. When you deprive a cell or tissue of oxygen, it starts losing 'performance'. It's like us humans. If we don't eat enough, we start getting weaker and weaker until we pass away due to lack of enough energy to keep the vital body systems working at a minimum pace. That's what happens to your brain cells. They start losing strengh and ever less electromagnetic impulses are transmitted between neurons. We all know electromagnetic impulses along with some chemicals are what constitute our memory, thinking and what transmits commands to the rest of the body via the nerves. So with less of them, we start not beeing able to remember what we've learned, take much more time to take decisions and move slower. Neurologists estimate that we forget about 75%, maybe more, of what we learned if prolongedly exposing the brain to low oxygenation situations.

You may find out later in your life that this is not unlike getting drunk, in regard to effect on brain power, as has been told.

You may find out later in your life that this is not unlike getting drunk, in regard to effect on brain power, as has been told.

I heard that as well, but don't have a real life experience to know how it feels like :(