Originally Posted by
physicus
...However, the TUC comment isn't: the 12-15 seconds at FL380 is not for an "acclimatised" body. If it was acclimatised, decompression wouldn't be a problem... get it? ;-)
Fair point. Acclimatized is probably the wrong term. What I was trying (poorly) to explain is that the 12-14 seconds UC is a notional figure based on the circulatory period of O2 around the body. However the lecturers on the high altitude course were adamant that it is a lot less during rapid decompression. Nitrogen in the blood turns to a gas (the bends) which causes blockages of the blood supply thereby reducing the length of UC. They listed multiple other unpleasant physiological effects that are best not recounted here.