Originally Posted by
deefer dog
Made 490 once...only just, and only to tick the box. Won't be doing it again in a hurry. Scary up there and in most things if you should be there you should be at TOD.
Both on O2 btw.
Thanks,
I have never been up that high. I assume that you use the normal O2 selection. Is much O2 actually used for a significant length of period on oxygen or is the mixture so low that hardly any is used.