Look guys, pressure breathing is based upon cabin/cockpit pressure - everything else is irrelevant.
The aeroplane I flew was officially cleared to 60,000ft, but has been higher.
In the event of pressurisation failure the oxygen regulator would automatically feed pressurised oxygen to the mask - all that was required was to pull down the mask toggle which would pull the mask very tightly to the face.
Now, the pressure suit and helmet and suit were something else.
Try this little lot.......
