High Altitude Cruising
A topic of interest is that i find it hard to understand why when cruising at high altitude ie FL 410 and above there isn't a universal requirement for at least one flight deck member to be on oxygen.
Surely give an explosive decompression in a jet transport aircraft at these types of Flight Levels the seconds of expected survival would dictate this requirement.
I believe Military fighters have pressure breathing oxygen above say FL 380 which pressurises the lungs.
Would 100 % oxygen at these levels in a passenger airliner be enough to push the required amount of oxygen across the lungs to prevent a very nasty sceanario ???