“Nerve gas doesn’t dissipate that fast especially in a closed environment. The hijackers in chem suits?”
It is not a closed environment. To maintain pressurization, compressed air is bled from the engines into the cabin. Outflow valves in the back of the airplane open and closed to maintain the desired level of pressurization. The air in the aircraft is recycled every few minutes.
Then them boys better have chem suits and be able to fly in them. Maybe that’s where the muffled radio call a few days back came from. Pilots in a mask.