[ According to one poster on the site: Depressurize the cabin at altitude after shutting down emergency oxygen supply to the cabin. Dead passengers in 3 minutes. ]
The old ones and the young ones would be first to die as well as anyone with a heart condition or repritory issue, some may survive, albiet pass into unconciousness...
You don’t really need extra O2 at 30,000ft to stay alive but you do need it to stay awake.
However once everyone is either dead ot knocked out by hypoxia, it would be a trivial thing for a hijacker to walk around the cabin and kill anyone left with a heartbeat....
They could get around the cabin by using the portable O2 devices the flight attendents use in case of depressurization...
If anyone did remain concious (say you has someone accustomed to high altitude living) they wouldn’t be able to put up much of a fight at 30k feet as they would get tired really easily even with adrenaline...
Could be another reason why they chose a night flight, most people would already be asleep....
The existence of portable O2 devices for the flight attendants means that any/everyone who knows about them and how to use them has to be taken out first.
Tall order that, unless the flight attendants are in on it too.
Both pilots are/were muslims. Raise that big red flag even higher.
Even with supplemental oxygen from the overhead drop-down masks, at 30,000 feet most passengers would be unconscious in a few minutes. Those masks don't flow much oxygen anyway (continuous low flow). It's only intended to keep them alive until the airplane can get down to a safer cabin altitude.