PPRuNe Forums - Emergency descent procedure

Quote:

Originally Posted by Discorde (Post 11464037)

Further to post #8: Has a recent assessment been done comparing the risk of the ill effects of hypoxia incurred by occupants of a depressurised aircraft versus the risk of collision during uncoordinated rapid descent? Should the relevant checklists be amended to prioritise clearance from ATC? Here's today's (08 July 23 1410 UTC) airspace activity over the NE US (a significant proportion of which will be operating in the FL300-400 band).

I think the picture shown is somewhat misleading as the aircraft are not to scale! Yes, there’s a lot about but they are spread through a huge volume, and if you multiply the chance of a full-on rapid descent by that of actually getting close enough to other aircraft to be truly worried, it would come out as a very small number, especially given ATC would be alerted (quickly if 7700 squawk) and most pilots I know keep SA in the cruise on other aircraft above/below them, which helps in these remote circumstances.

I think someone in the UK in the 1960s (?) proved statistically that with the traffic levels then and the measured collision risk, it would be safer in this one respect to get rid of all en-route controlled airspace and assign aircraft random heights and headings than it was to try and have them follow airways and ATC direction.