My piloting experience is very limited, but the scenario that seems most likely IMHO, given everything we know about the crash so far, is that some of the instruments malfunctioned due to the storm (see the references to the pitot icing problems); the pilots and the automatic equipment didn’t know which way was up and what their true speed was. This led to improper corrections, worsening conditions, and they lost control or the plane exceeded design parameters.
Just remember: that high, that fast, in a severe storm at night, you can’t just look out the window to get your bearings, and you can’t rely on your instincts to tell you which way is up, which way you are going or how fast. You are totally dependent on instruments. What happens if one airspeed indicator says you are going too slow, and the other says you are going too fast? What if one dial is “stuck,” and says you are at a constant altitude but you are really heading straight down?
As an example, if the pitot tube was getting narrowed by ice accumulation, the apparent airspeed would be decreasing. If the tube was blocked, it would say you aren’t moving at all. Let’s say the pilot increased speed to conpensate and got hit even harder with the storm.
So to answer the OP, it was probably a nightmare until the plane broke up. Then it got worse.
From the Daily Telegraph: “Experts said the most likely scenario was that the break-up was caused by massive depressurisation inside the plane … As Philippe Juvin, a French doctor, explained: “If depressurisation is extremely brutal, you lose consciousness and a deep coma sets in. It would have been like falling asleep.”
Actually, if decompression is fast and extreme enough, you can be ripped apart, see Byford Dolphin. However, the pressure differential between an airliner and the atmosphere is not sufficiently great to generate that effect
Yes, if decompression is “sufficiently brutal” you can lose consciousness but it’s not guaranteed. Testing of human subjects in altitude chambers reveals that there is a range of response in any group of individuals. Also, we don’t know how “brutal” this decompression was, if it was fast or slow, if it had occurred before or after an airframe breakup… There are MANY instances of people retaining consciousness during and after an airplane depressurization, in fact, I’ve even spoken with people who have directly experienced it. The effects vary with altitude, speed of pressure change, the individual, and so forth. It is not always “brutal”.
Who are these “experts” quoted by the Daily Telegraph? What are their credentials? Who is this doctor? Does he have credentials in aviation medicine or experience with barotrauma? It looks to me like he’s hoping that the people were knocked out, but did he know that? On what does he base that opinion? And it would be helpful if you linked to the original articles you took that information from so we can read them independently and fact-check them independently.
The only Phillipe Juvin I could find on the internet was this guy who, although he is a medical doctor, seems to function primarily in government and politics in France. He has been appointed to a health commission and another on Alzheimer’s, and apparently has experience in anesthesiology and intensive care. My apologies for those who don’t read French - I couldn’t find much on him in English but I have tried to summarize what was in the French wiki. Indeed, in this reference he makes a response in a respected, peer-reviewed journal of anesthesiology discussing difficult intubation (that IS in English). All very worthy and wonderful things, however, nowhere do I see listed any experience in aviation-specific medicine, barotrauma, or even high-altitude medicine. In other words, he has no specific and specialized knowledge of the subject. I believe I found the quote you mentioned, but it was one sentence and potentially out of context, from someone with no particular expertise in the area being discussed. Oddly enough, he is not quoted in the French media, which makes me think this may have been a case of English-speaking reporters latching onto someone in France who looks official and speaks English. There is a LOT of coverage of Flight 447 in the French media, with quite a few official statements, but as I said, none from Juvin among the official statements.
You see, those of us who have been here awhile know LSLGuy as a professional pilot who flies “big iron”, and a number of us know that those guys have to have specific training in regards to flying pressurized aircraft, including what happens when the system breaks down and what to do about it. I don’t know anything about these people you say were quoted in the Daily Telegraph. Without further information I can’t evaluate the quality of your sources. They may, in fact, be quite solid and prove some of us wrong but until I have more information I just don’t know.
Is this correct? If so, the failure would be immediately obvious, and therefore much less dangerous. The way I was taught is that if the pitot is blocked, the airspeed indicator reading remains constant, unless you climb or descend. If you climb the static pressure reduces and the airspeed appears to increase, and vice versa.
Another nervous flier here – and I feel grateful to a fellow passenger some years ago who looked at his white-knuckled neighbour and quietly opined: “I like turbulence, it reminds me that there is something holding the plane up”. (For some reason I found this reassuring and some blood managed to get back into my fingers).
I do wonder if a number of the quotes that make the papers re. comforting unconsciousness prior to the impact make it there in order to reassure the readers rather than as solid medical opinion.
Exactly. I have no idea if that Doctor Juvin guy is reliable, I never said he was. The point is I find it irritating when people like LSLGuy come into my thread and instead of answering the question make assertions like it’s “guaranteed” the passengers would have been conscious for the whole experience - something which is by no means a consensus opinion - with no explanation or justification whatsoever, then rant about how I’m “psychologically arrogant” or something when I press him for explanation. That’s useless to me.
Keep in mind that when LSLGuy goes to work he’s gone for several days at a time with sharply limited access to the internet, if any at all. You may not be aware of that. This is a good thing, as he needs to be flying the jet while at work and not posting to The Straight Dope. Typically, he responds a little slower than the rest of us and may not be able to provide definitive cites until he gets back home. That’s why sometimes the rest of us try to help him out though, of course, we also try not to put words in his mouth.
Anyhow, the Free Fall Research Page, linked to up-thread, provides evidence that people have fallen from great heights and survived, Vessna Vulovic currently holding the record at a 33,000 foot fall without parachute and surviving, riding the airplane wreckage down to the ground. Information on actual experiences of decompression and airplane break-up has been gleaned from numerous lucky survivors. Reports vary, with some claiming no memory of their fall and others providing considerable detail. For example, Lt. Col William Rankin bailed out of his military jet at 47,000 feet, lost his oxygen mask, but remained conscious for almost all of the subsequent 40 minute ride through a thunderstorm which carried him from Virginia to North Carolina.
In light of this, I see no reason to conclude either way that the people aboard Flight 447 were aware or unaware. Given the circumstances, there was probably a range of states of awareness between unconscious (or even dead) and fully cognizant of the situation. Some people might have, indeed, perished from heat attacks or a blow to the head. Others may have indeed been aware all the way down.
This is one reason why recovery of the bodies is seen as important. Injuries can reveal significant facts about the last few minutes of the flight and subsequent fall to the water. For example, true explosive decompression tends to cause lung damage that is revealed at autopsy. Slower decompression does not. Water in the lungs can indicate drowning, meaning the person was alive when they hit the water, perhaps even briefly afterward, whereas those who die at altitude will usually have lungs without water in them.
For example, the BOAC Flight 781 Comet break-up in 1954 pre-dated black boxes but the pattern of injuries in recovered bodies permitted reconstruction of the accident, and the distinctive lung damage indicated genuine explosive decompression that, combined with a violent break-up of the airplane, resulted in a case where people probably genuinely had no idea what hit them and really were dead before final impact. On the other hand, in 1961 the Yuba City B-52 crash the airplane was able to descend to 10,000 feet after decompression and, despite crashing due to lack of fuel, everyone aboard survived without injury.
What it comes down to is that each accident is unique, and it’s impossible to definitively say whether the passengers were aware of the fina falll or not until an investigation is complete. In the past, both scenarios have been found to be true at different times.
Atually, I believe there are typically two tubes, one facing into the wind, so to speak, the other at right angles to it. The difference in air pressure between them can be used to compute the airspeed.
If one or the other tube is not fully open, it would affect the readings. Whatever effect it might have is not good and might not agree with expectations or other instruments.
That’s not going to work even if it were reliable, not subject to electronic failure, atmospheric interference. What matters to avoiding stall is relative airspeed – if there’s a 200 mph headwind or tailwind, knowing how many miles of ground you’re covering (all that GPS could tell you) gives you no help in knowing how much thrust to apply. In fact, “airspeed” is basically defined as Vg (groundspeed) - Vw (local net wind speed).
Pilots use to carry portable GPS’s with them when they first hit the scene because the planes they flew had not been retrofited yet. It seems to improbable to have a complete loss of display so I doubt anybody carries them anymore.
Wow, this was a fascinating thread. Thanks LSL Guy, that was compelling. My FIL used to investigate jet engine failure, Sioux City gave him nightmares. I’d never ask him about his work.
Broomstick - how about when you hear an electronic voice in the cockpit (which you can hear clearly b/c it’s a very small plane) saying, quite clearly, “Pull up! Pull up!” Personally I took that as a bad sign (though clearly I did live to tell).
which was a vivid enough description of what it would have been like for those poor people that I (a totally blasé flyer) am now a little creeped out about the next time I am going to have to get on a plane. What else were you looking for? Perhaps it would help if you refined your question a bit?
As a person with a completely irrational fear of flying, and an (ironically) overwhelming desire to know what might happen in a plane crash, I do appreciate your comments and perspective. It is interesting (though morbid) to get the details of what might have happened in this situation from an expert.
However, your approach in explaining the facts, rational and cold as it may be, came off as a little harsh simply because the details you include are horrifying to realize. As you implied, people don’t want to hear about these potential realities because it is too difficult, too horrible, too terrifying to accept. That is, knowing the truth about what might happen in this scenario creates an intense sense of anxiety in the average person.
There are a number of ways to deal with and alleviate this anxiety and here are a few I can think of: First, you can completely avoid the topic by convincing yourself that a crash will never happen to you (and this is really the most rational approach given the statistics of aviation disasters); Second, you can avoid flying altogether (not very practical but common enough I imagine); Third, you can convince yourself that you will be unconscious for the whole thing; Fourth, you can accept that it would be a horrible death and deal with the anxiety (which is extremely difficult and uncomfortable). Out of curiosity, and because I struggle with this myself, how do you deal with such anxiety? Or is this even something you think about? Is there a particular category (above) you would put yourself in?
With that psychological rationale established, I have to disagree that it is “psychologically arrogant” to be unsettled by your comments - in fact, in my professional opinion (I’m a social psychologist), it is psychologically normal to have that reaction. That is not to say it is the most productive or most appropriate response (from a rational standpoint), it is simply the most adaptive human response in dealing with the anxiety created from reading about such horrible fates. Along the same lines, I don’t think it is exactly cowardice to not want to relive others’ past horrors; it is just easier to cope when we can believe that these situations were not as horrifying. Of course, it is crucial (as you allude to) that humankind learn from its past mistakes, whether it be from the Holocaust or Airplane crashes. It is just that the majority of the public is not built to deal with this information and it may not always help to inject this information into the general public. For instance, if your comments about what might have happened with the Air France plane were readily shared in every media outlet, I think it is fair to say that the airline industry would take a significant (albeit temporary) hit due to a terrified public.
Once again, thanks for your comments. My only intent here is to clarify things from my perspective and to also get you take on how you personally deal with the issues discussed in this thread.
The kerfuffle over LSL’s tone here reminds me of a line in Richard Bach’s Illusions - The Adventures of a Reluctant Messiah, a little book that’s about as New Agey as you can get: “You’re going to die a horrible death, remember.”
