Safety Demonstration

Because we need more oxygen to breathe than is in the outside air your aircraft is designed to be pressurised. What that means is that extra air is pumped in from outside.

Note that the air pressure in the cabin, while enough to breathe comfortably, is not the same as at sea-level. That is why you will still feel your ears pop as the aircraft climbs.

To maintain sea-level pressure would require an aircraft with the weigh of a submarine... and probably similar flying characteristics! The cabin air pressure will, typically, be as if you had climbed a 8000 feet (2500m) tall mountain.

Ok, what if that stops working?