Yeah well, I have couple years head-start on ya. But be careful kid, dont go trying out tonight. Wait till you are of legal age and even then drink responsibly. It is never a nice thing to have to have an ambulance call on you because you are passed out drunk out of your mind in the night somehwhere, and you can still be glad at least somebody called it.

Thanks for you concern, Peter, but don't worry 'bout me. I'm about to turn 17 (legal age here in Brazil is 18), but I don't have the least will to drink alcohol. Never did. I'd rather stick with juice and soda for the next few years :(.

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!

The errors are always human, it is called human factor. You will find always a guilty for each accident in the world. Maybe the pilot, the technician, both, the engineer, the designer, the producer, the rivet manufacturer and so on...As the errors are always present, it is a good thing to do a system Murphy proof. (See Murphy's laws)The pressurization system as it is, with checklist only is not Murphy proof, and Helios demonstrated this.A caution or warning, light or aural, or also only a digital voice at a certain altitude informing about bleed, pack, switch in manual could be useful to prevent the common errors.The helios was not the first to start the flight unpressurized, the common error in the 737 is to leave the packs off, it happens too often, 2 times also in our company.When you play with checklist every day, a lot of time for each day, it is human to "jump" a step or just say "set" when you have not seen the switch.

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.

Thomas I hear you...The only way to be able to react to hypoxia is to know when it is happening. To know this you need to experience it in a controlled environment. Enquire with your airline as to the availibility of decompression chambers, and find out if you can have a go in them. If not, visit your nearest friendly air force fast jet unit and ask.IMO this training should be done for all cabin crew so you are aware of the effects on yourself and also so you can be able to tell if others are being affected by it. I am not sure why it isn't done.

... A caution or warning, light or aural, or also only a digital voice at a certain altitude informing about bleed, pack, switch in manual could be useful to prevent the common errors ...

Multiple contributing factors as usual BUT when depressurisation caused the crew's oxygen masks to drop down - a bit of a clue you might think - they didn't bother to put them on. Absolutely excusable IMHO.Tim

This is something some of you probably have heard before but it's a pilot of a jet who is very much affected by hypoxia but still hasn't passed out, which his co-pilot has however.

In the comments one preson writes:I know these pilots. The reason the second pilot didnt talk is because he was passed out. The only reason either of them lived is because they had the autopilot off since the captain was an old school pilot and flew by stick, so the muscle movements kept him alive long enough to decend.Very interesting to listen to, especially how quickly he comes around once they have descended. In all its misery the part that starts at 1:02 is actually kinda funny.

Edited January 27, 201214 yr by Krister

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?

Actually, when I got my license it was said in "human factors" that from 0-10,000 feet you are only slightly affected by hypoxia and may notice some of the symptoms like degraded night vision. Above 10,000 f your body will counteract by increasing your breath rate but after a while it's not enough and you will risk unconsciousness.At 18,000 feet you have about 30 min where you conscious enough to know what you are doing so to speak while at 40,000 feet you have less than 20 seconds. I'm not totally sure about the figurs but it was in those regions.

Multiple contributing factors as usual BUT when depressurisation caused the crew's oxygen masks to drop down - a bit of a clue you might think - they didn't bother to put them on. Absolutely excusable IMHO.Tim

AFAIK the crew's oxygen masks don't drop down automatically. The crew have to take them out of their holder and put them on themselves. You can see where they're kept on the NGX.

Multiple contributing factors as usual BUT when depressurisation caused the crew's oxygen masks to drop down - a bit of a clue you might think - they didn't bother to put them on. Absolutely excusable IMHO.Tim

Tim,As John said crew masks don't drop down automatically. Why didn't they do anything when the passengers masks dopped I hear you ask?Correct me if I'm wrong but the pressurisation switch was set to manual. Therefore unless the crew were manually controlling the a/c pressurisation, then the aircraft will not pressurise. So therefore it will not depressurise.The depressurisation you are referring to where the masks will drop down and people are in crontrol is rapid decompression caused by some type of fault. Usually a structural failure. Up to this time passengers are conscious and fully functioning.The decompression/oxygen deprivation suffered by the passengers and crew was gradual. In my eperience in a decompression chamber, after two minutes or so I couldn't even spell my name properly and after even more, I had to be helped to put my mask on! The worst thing, is that I felt I was fully in charge and was doing everything perfectly! Oh how wrong I was.Look up Hypoxia on You tube...I'm sure there are videos there.So in that case maybe when the masks dropped, possibly, the state of hypoxia had already set in where people thought they were in control but they really weren't. Hence crew apparently waving at the F-16 without even thinking #####??Think climbing Everest. There are many rest camps on the way up, because and not limited to the need for acclimatisation to the 'thiner' air. So think days to acclimatise vs minutes at high alt....

Edited January 27, 201214 yr by Richiebacardi

yea the pilots mask dont drop down they have to put them on themselves so when there smoke in the cabin then they automatically put their mask on. but with hypoxia that a different story all together you got no idea whats hapening around you, unless you have had training in this situation and reconignise the symtoms.But by the time time you reconignise whats happening its too late

yea the pilots mask dont drop down they have to put them on themselves so when there smoke in the cabin then they automatically put their mask on. but with hypoxia that a different story all together you got no idea whats hapening around you, unless you have had training in this situation and reconignise the symtoms.But by the time time you reconignise whats happening its too late

There's quite a detailed account of this at the aviation safety website which I understood to indicate that the crew masks had descended but if this is impossible then I and/or they must have got some wires crossed.Tim

This is something some of you probably have heard before but it's a pilot of a jet who is very much affected by hypoxia but still hasn't passed out, which his co-pilot has however.

In the comments one preson writes:I know these pilots. The reason the second pilot didnt talk is because he was passed out. The only reason either of them lived is because they had the autopilot off since the captain was an old school pilot and flew by stick, so the muscle movements kept him alive long enough to decend.Very interesting to listen to, especially how quickly he comes around once they have descended. In all its misery the part that starts at 1:02 is actually kinda funny.

Wow. I've never heard that one. Good find. I'm surprised that hasn't found it's way into one of my recurrent ground schools by now.

A caution or warning, light or aural, or also only a digital voice at a certain altitude informing about bleed, pack, switch in manual could be useful to prevent the common errors.

I wish they'd update that. My plane yells at us when we're approaching a runway or on a runway (yes it says, "Approaching Runway 33"). That's high tech stuff. But they can't improve the Cabin Alt/Config warnings. Well, they could, but $$$.

It is not so difficult, tha cabin altitude switch is a simple switch that can be used to pilot a message on the eicas, a digital voice from a box, a simple light, and so on.But you're right, a simple light, added to the men power, to the hangaring, projects and so on, it will be expensive, but compared on how the system is weak of protections/alerts, it could be preferred compared in a loss of human life.

It is not so difficult, tha cabin altitude switch is a simple switch that can be used to pilot a message on the eicas, a digital voice from a box, a simple light, and so on.But you're right, a simple light, added to the men power, to the hangaring, projects and so on, it will be expensive, but compared on how the system is weak of protections/alerts, it could be preferred compared in a loss of human life.

Each warning light on a 737 needs four wires to it, so it's not so simple, but as you say it can be done. Really the failure in this case was to do with training. The crew should have known that an intermittent horn in flight meant excessive cabin altitude, yet for some reason they decided it was to do with the takeoff configuration warning system (which only works on ground). The multiple use of one aural warning for two things is not unusual in Boeings. All Boeings of the 1960s and 70s era (and that includes the NG) use intermittent and continous horn warnings in exactly the same way as the 737.Having multiple aural warnings is not always a good idea either. Several different warnings going off at once will only cause confusion, The MD80 is an example of an aircraft with a lot of different voice warnings some of which are hard to understand and distinguish and not always obvious how to clear or cancel.