47

To add to Daniele's answer, from the final report: The forensic report concluded that the aircraft occupants had heart function during the impact. The report noted that this did not necessarily imply that they were alert. The report further estimated that they were in deep non-reversible coma due to their ...


37

Consciousness requires quite a bit more oxygen than merely being alive. Human beings can last remarkably long with very little oxygen, but not remain conscious. And lack of oxygen will soon enough cause permanent damage. The passengers may have been alive, even if they were not conscious, but they could have been anything from temporarily incapacitated to ...


23

If you are asking about all or some of the masks as your title suggests, it has happened before. One such example from 2008 is Qantas Flight 30. After the accident, numerous passengers said that some oxygen masks did not deploy, whilst others had deteriorated elastic. Consequently, it was reported that one passenger smashed a panel of the ceiling to ...


21

The point is not that the oxygen is used up. Even after a depressurization, the air around you still contains so much oxygen that it would take your body (at rest) hours to burn it all. But this oxygen is spread out so thinly that a standard set of lungs will not be up to getting enough of it from the cabin air into your blood at the rate your brain needs. ...


13

Here is a list of those people who survived as stowaway in the unpressurized and extremely cold wheel well. On June 19, 2015 an unidentified male who was 24 years old survived 11(!!) hours in the wheel weel of British Airways Flight 54 from Johannesburg to London. As you also see, this is incredible because as you suggested most of the people simply die. ...


13

Yes, there is an indicator for passenger oxygen status. (Image Source: www.b737.org.uk)


11

In addition to SentryRaven answer, this is the same for Airbus (A320): (source: FCOM A320 at SmartCockpit.com)


10

No, you cannot - at least not with the default masks. In principle, the oxygen systems on board can all provide at least 15 mins. of oxygen, in some of the worst conditions (indeed, that's what they're designed to do). However, their sole purpose is to make high altitude air breathable. The key principle here is partial pressure. Basically, the partial ...


7

The problem with high altitudes is not the lack of oxygen, but the lack of pressure. At lower pressures, your lungs are less effective at getting the oxygen into the blood. Oxygen masks on airplanes increase the amount of oxygen in the air you breathe, which helps the lungs to absorb more even in low pressure. In a typical decompression, there will be a ...


7

According to this Airbus training manual, pages 10 and 11, that's the test door stop. As you can see in the video you added, resetting the masks is a pain, so the little red stop is there to catch the door and stop it from fully opening. Manually operated doors stops are fitted on the container doors to allow an operational test of the mask release ...


6

This question is best answered on https://biology.stackexchange.com, but in short it is the partial pressure that counts. This is (pressure in atmospheres) * (percentage). At 0.5 atm (18 kfeet) you need twice the amount of oxygen in the air (aka 40%) for it to have the same effect on you. Above 38.5 kfeet the pressure is 0.2 atm, so even 100% oxygen will ...


5

At high altitude, the time for useful consciousness is measured in seconds. Pilots are trained to take on the mask immediately when the alarm goes off. The problem of your approach lies in two uncertainties: Uncertainty of cabin pressure. Unless you happen to have carried a altimeter with you, of course. Uncertainty of the oxygen level in your blood. ...


4

So in premium there's an extra step For what I see in the picture you posted, not really. There is always the step "grab the mask and pull firmly" to bring it from the compartment to your mouth (and break the supporting cable, that is now unneeded, in the process). What I understand from the third picture (first row) inside the image you posted is that ...


4

Very, very rare, probably in the range of sinlge digits per 100,000 flights (for major first-world airlines, perhaps higher elsewhere). I'll try to get you a more numeric answer tomorrow. Posting an answer now so that I can edit it, evem if the question gets closed between now and then. "Opinion based", horsefeathers!


4

The oxygen system for passengers in an airliner is generally powered by a chemical oxygen generator. The generator contains chemicals, which when they come into contact with each other, commence a reaction that produces oxygen for a few minutes. The act of pulling down the mask triggers the contact between the chemicals. A generator typically serves two or ...


3

The answer is you don't need more oxygen. You need exactly the same AMOUNT of oxygen. But the density of the atmosphere decreases as you climb to higher altitude. (the density is created by the weight of the air above you). So the AMOUNT of oxygen in each cubic inch of atmosphere (or in each breath you take) decreases. To compensate for that, to keep the ...


2

There is a maintenance schedule to test the mechanism that causes the passenger masks to deploy(drop down). It is usually performed each 12 months. During this test, the masks themselves are inspected, any discrepancies found dealt with, and re-stowed in the little overhead box until the next scheduled inspection.


1

the pressurization system in a fighter plane might be able to furnish 10,000 ft cabin altitude at 30,000 feet, but the pilot would need supplemental oxygen when flying higher than that. In addition, if the cabin is breached above 30,000 ft the pilot would have very little time to get his or her mask on before blacking out, so the mask is worn at all times.


1

Always put your mask on immediately. Cabin and flight crew do for a good reason! You may not be aware if it's a slow or rapid decompression. A rapid decompression will result in much less time available for you to remain conscious and save yourself. This is the same reason you are advised to don your own mask before helping others, so you don't put yourself ...


1

It depends on how much oxygen is provided by the mask, i.e. what the flow rate is. I guess masks for pilots should be independent from ambient air at any altitude for the case that there's smoke in the cockpit. So yes, they would provide enough air for breathing at sea level, or even slightly under water. But those masks are in the cockpit and not mobile. ...


1

It is a chemical reaction. So yes, if contained it could provide oxygen under water (provided the reaction did not react with the water). However, it would not work for the reasons already mentioned in the comments and the infeasible logistics of a hollywood captain single-handedly saving his passengers at the last second ;-) https://en.wikipedia.org/wiki/...


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