[Hotfoot]

Solutions to problems with the sleeping gas problem:

-ensure that the essential crew, pilots, co-pilots, navigators, all have an independant air supply in the case of an emergency. Even their drop-down oxygen masks could be modified for the job.

-give pilots catheder bags. I think there's a john near the cockpit anyway. You could seal off everything after that.

-if for some reason the pilots are incapacitated as well, use the regular update code I mentioned earlier. If the pilots get knocked out, autopilots take over and level the plane out and keep it locked at a specific "safe" altitude.