Originally Posted by
dr dre
So the oxygen bottle ruptured, took out the transponder and the cabin altitude warning system but left most other systems intact.
I don't think anyone said the cabin altitude alerting system failed. It defaulted, according to this theory, to a higher trigger value but did not fail.
Originally Posted by
dr dre
It ruptured a hole in fuselage just the precise size needed to let air leak out at such a small rate it would not be detected.
No, that's not what anyone's saying. It would be detected by any conscious person with the presence of mind to check the cabin altitude indicator and would eventually trigger the cabin altitude alerts. In this theory, however, it was not detected and acted upon and presumably when the alerts were finally activated the pilots were no longer conscious.
Originally Posted by
dr dre
Even the tiniest of holes is still going to have air leak out of the cabin at a rate of about 1000ft per minute (and I'm being very generous there, in reality it should be much more).
You seem to forget the effect of the still-functioning packs which would be working, but failing, to overcome a leak of the right magnitude. There is nothing unrealistic about this circumstance.
Originally Posted by
dr dre
At a cabin altitude of 8,000 to 30,000ft (where useful consciousness is about 1 minute) will only take 20 minutes.
No, see above. It would take much longer. How long exactly is unknown.
Originally Posted by
dr dre
QF30's ruptured oxygen bottle caused an almost instantaneous loss of all cabin pressure when it breached the fuselage.
If the MH bottle had failed in the same fashion it would've had a similar result. Obviously it didn't fail in exactly the same fashion. If it had, now that would be harder to believe.
Originally Posted by
dr dre
The incident with the Kalitta Learjet in the previous video lasted a grand total of a few minutes, from the pilot descending from FL320 to a more breathable FL110. A few minutes, the time of useful consciousness at FL320 is about 1-2 minutes, so even though he was slurring his words (hypoxia effect) he had just a minute or two to get the aircraft down to more breathable air before he lost the motor skill capacity to make control inputs.
That's extremely misleading and plain wrong. As we know from Avmed, every 1000ft lower increases the time of useful consciousness. At FL250 it's 3-5 min. At FL200 it can be 30min. Obviously these figures vary from person to person and are worse for smokers.
Originally Posted by
dr dre
Yet the decompression story requires us to believe that a pilot stayed conscious in that environment for almost an hour with no supplemental oxygen then made a control input to turn the aircraft to the south? Simply not believable.
If you can understand the above factors you can see how a gradual decompression fits the theory neatly.
Originally Posted by
dr dre
15,000 ft is the elevation of cities in Peru and Bolivia, so not exactly where hypoxia sets in without supplemental 02. It’s in the 20,000ft range.
I'm not sure how in-depth your avmed training has been but I suspect these days it is pretty short for a lot of pilots. Have you been in a decompression chamber? If you have only then will you best understand how hypoxia can affect different people at different rates and in varying ways during onset. People who live in Peru are born and bred there and well and truly adjusted to it. KL (where I think these guys lived) is at sea level. You can see the point, I think.
Also, it is implied the pilots were smokers. I've had smokers report difficulties breathing at only 10,000ft in an unpressurised aircraft.
Originally Posted by
dr dre
It means you have to believe they were overcome by hypoxia to make irrational decisions but then recovered from that hypoxia to make conscious inputs once again a long time later.
Once again if you haven't been in a chamber it will be difficult for you to appreciate how hypoxia will affect you. You rule it out as a factor based on your belief or knowledge or feelings about the condition; Others, based on theirs, do not.
Humans will begin to make errors and experience difficulty assimilating information at early stages of hypoxia but without losing consciousness. It is impossible, in this theoretical scenario, to predict the effect of hypoxia on the awareness and decision-making abilities of these pilots other than to say it would be impaired to slowly increasing degrees and would appear to a healthy observer (such as you) to make no sense.
Speaking of Helios, there is a very prodigious (and some say pesky) poster around here who I seem to recall has firsthand experience of a scenario almost identical to the Helios event but with a happier ending. He's notable by his absence on this thread but it would be very interesting to hear his take on it all.