why is the oxygen levels different at night?
I have absolutely no idea - that's the first I've ever heard of it.
what effect diminished oxygen levels can have on you and your ability to fly the aircraft safely.
Hypoxia is an interesting beast. I've experienced it inside a decompression chamber at an equivalent altitude of 25000ft, at which you're really looking at a maximum of 3-4 minutes before you're going to die (because if you haven't taken action by 3 to 4 minutes, you'll pass out, and not recover). We conducted a series of simple exercises, starting with adding shapes (where different shapes represented different numbers), then relatively simple arithmatic, then copying patterns and so on and so forth. The key thing was you could feel yourself having to really concentrate on completing each task, but as time progressed (2 to 3 mins, by which time you're feeling light headed and slightly euphoric) you still thought you were doing rather well. When the doc finally gave you your mask back (somewhere between 3-4 minutes) and you took on oxygen again you realised how badly you had done, how bad your copied shapes were, and how scruffy your writing became.
It was an interesting an enlightening experience - certainly I feel that I am as well equipped as I can be if I ever feel I am experiencing the symptoms.
The worst thing about GA aircraft is as they'll be flying lower (say up to 15-20000) is that the onset of Hypoxia will be a lot slower, so potentially much more difficult to recognise, and therefore prevent.
by spirit1flyer » Tue Aug 16, 2005 2:32 pm 
...?
