[QUOTE=G SXTY;11940225]
I
carry medical oxygen with me if I expect to have difficulty breathing, e.g., when at 8000 feet equivalent, such as in a 787. [/QUOTE]
Small point, but the 787 is normally pressurised to an altitude of 6,000’ rather than 8,000. One of the reasons the cabin environment is nicer than in other, erm, older Boeings. And in the unlikely event that drop-down masks are required, the supply is good for around an hour. Even I can manage a rapid descent in that time.
You are not going to run short of O2 on a 787 - or indeed any other modern jet.
That's depressing. It means my remaining lung isn't giving me sufficient oxygen for me to feel comfortable at 6000', not 8000' as I had previously thought.
At SFC I can walk for about 20 minutes on the flat before I get really breathless and need to sit down and gasp for air. Aloft, as I'm just sitting and being served food and drinks (lots of drinks, especially on EK!) the lower oxygen pressure doesn't seem to matter on an A350, but does on a 787. Can 1000' really make that much difference?
I actually have slightly over 50% lung function, I had half a lung out, but in the process the left lingula became strangulated, so I only have a bit of lung function left from the bottom of what's left of my left lung.
If you have knowledge about lung function vs. effective altitude, I'd be grateful to know about it. The last thing I want to do is board an unpressurised aircraft and find that the little cylinder of oxygen I carry runs out before the flight does. I get enough grief at LHR and EMA taking *any* oxygen on board.