I'm going to take another opinion on a few items in your last post.
"...Above FL410 pilots are required to wear an oxygen mask at all times. There are some exceptions to this rule, such as the Concorde and some bizjets. All aircraft that fly at high altitude require quick donning masks that can be put on with one hand in 5 seconds or less..."
This statement is partially true. In the US (I have no idea about the regulations of other countries.), the regulations on wearing of 02 masks kick in at various altitudes - depending upon what section of the FARs you are operating under, Part 91, 135, 121, etc. For commercial operations (Parts 135 & 121) the requirement to use O2 masks kicks in at 25,000' for non-commercial operations that altitude is increased to 35,000'. IF
the aircraft is equipped with quick donning masks, then you are give some options as to their wearing and use. As far as I know, there are NO exceptions to the rules (again, the Concorde wasn't a US registered aircraft) so no bizjets are exempted from the regulations. If you've ever been in a cockpit at FL370 or higher, don't be surprised if the crew is taking certain "liberties" with the wearing of their masks. Those regulations are probably the most frequently "overlooked and ignored" regulations we have.
"...Take the Payne Stewart crash for instance. Fighter jets noticed the inside of the windows were frosted over. This was most likely caused by a rapid decompression. The pilots obviously didn't have time to recognize this and put on their masks. All occupants went unconscious and the aircraft ran on autopilot until it exhausted it's fuel. Most aircraft have a system that will deploy the pax oxygen automatically above cabin altitudes of about 13,000 feet..."
First of all, the official explanation of the Payne Stewart crash is still listed as UNKNOWN. That being said, I'm typed in the Lear series and have nearly 3,000 hours PIC in the Lear 35 and I have always been bothered by certain points that were brought out in the investigation.
A couple of months ago, I returned from my 6-month Gulfstream G100 recurrent training at FlightSafety. During our discussion on pressurization systems we had the obligatory discussion on the Payne Stewart accident. The systems instructor brought up some new information that sheds new light on what may have happened.
The thing that always puzzled me about the accident was that, in my opinion, they overlooked one item - the Lear 35, while only certified to FL450 has the same pressurization system that is certified to FL510 in their other airplanes. The Lear's pressurization system has automatic cabin altitude limiters designed into it that make it impossible for the cabin altitude to go above 14,000' or so (Not 13,000' as you mentioned in your post.) in a structurally sound
airplane. Remember the reports? The F-16 chase planes saw no evidence of airframe damage - only frosted up windows. 14,000' is hardly an altitude that will bring on terminal hypoxia.
The fact that the windows were frosted means nothing - only that the cabin temperature control hadn't been turned up. At low altitudes, the cabin gets pretty warm because of the pressurized air. It's normal to have the heat turned way down and or the airconditioner turned on to compensate. If you've ever spent much time in a Lear at altitude you'll know that they do have a tendency to frost the windows - especially if the heat's off and you've got a bunch of people in the cabin. No big surprise there.
This didn't make any sense to me until the FlightSafety instructor mentioned that they have recently found witnesses who mentioned that the passengers had loaded some frozen fish in the baggage compartment in the cabin behind the rear bench seat. There are also witnesses who say that there were several pounds of dry ice packed with the fish.
That changes everything. Dry ice is a VERY dangerous commodity to carry in the passenger compartment. It will readily displace the oxygen in the space and easily explains the accident. It wouldn't be the first fatal aircraft accident involving dry ice.
It remains to be seen if this new information will be confirmed and if it will have any effect on the official report.
As to why holding your breath won't work? It has to do with the oxygen partial pressure. At those altitudes, you just can't get the oxygen, at the molecular level, to transfer through the cell wall into the red blood cell.
I'd like to make a suggestion for all of you guys who are flying high performance aircraft (or hope to someday). Get yourselves scheduled for a ride in an altitude chamber. The cost is VERY reasonable and you'll walk away with a new found respect for your physical limitations. There are several chambers located around the country, I'd just give your local FSDO a call and get them to point you in the right direction.