Loss of packs
Perhaps I didn't express myself clearly enough. My question is , with the outflow valves closed and the aircraft effectively sealed, is there enough oxygen in the recirculating atmosphere in that fuselage to sustain life for 3 or 4 hundred people on what may be a long leg to the nearest suitable airfield? After the cabin is depressurised below 10,000' through normal leakage, maybe the outflow valve(s) could be opened to encourage some flow but where is the air inlet in this situation? Ram air? where from? DV window???