Appoligies for the thread drift.
My dear CL300
Yes I fly an aircraft that doubles up as a life support system at "high altitude". Don't fly very often now but I am employed as a pilot. Employed to fly passengers from A to B with safety, uppermost.
Aerodynamically I have no problem with your argument on the certification process. It is the physiological aspects I have an issue with here.
My max cruise is FL410 normally.
I used to be young and bold. I am now old but not bold.
If I may suggest you have a read over
this I draw your attention to the following extract below.
"At 40,000 feet, a person breathing 100 percent oxygen will have the same partial pressure of oxygen in the lungs as a person breathing air at 10,000 feet. Therefore, 34,000 feet is the highest altitude at which a person would be provided complete protection from the effects of hypoxia, and 40,000 feet is the highest altitude at which 100 percent oxygen will provide reasonable protection for the time period needed to descend to a safe altitude."
If the above makes someone think twice before climbing to FL510, my work has been worth while.
Think of your passengers and try and keep them smiling.