How do we get oxygen inside aircraft while it is completely sealed?

Question

How do we get oxygen inside aircraft while it is completely sealed?

Answer 1

Usually it is pressurised from the outside using the engines as power, so its not sealed but heavily controlled by a computer. When there is a cabin decompression, the oxygen masks convert CO2 into oxygen for 12mins

Answer 2

Most commercial aircraft have two aircon conditioning pacs, air from the engines and apu compressors enters the pac's at roughly 200degrees. The hot air is run through an air cooler, which is cooled by outside ram air. Water vapour is added to the air and is also passed through filters. The cabin air temperature required is regulated through a mixer unit which balances cold and hot air.

Near the aft of the aircraft there are pressure regulating values which are computer controlled to control the amount of air leaving the aircraft.

In the event of smoke entering the cabin the engine bleed air ducts can be shut off and outside unconditioned air(temperture, the pressure will still be maintained) can enter the cabin.

The aircraft can actually be completely sealed off in the event that the aircraft has to crash land on water. This is to stop water entering the air intakes and exhausts which would cause flooding.

Answer 3

It is continuously recycled.

Answer 4

pressured so the plane doesnt fall apart while high altuides and speeds

Answer 5

It is not completely sealed.  It is pressurized.  Airplanes do take oxygen from the outside, filter it,  heat it (air at those altitudes are extremely cold), regulate it and send it to the cabins.  If the plane was completely sealed the passengers and crew would die from carbon dioxide poisoning before lack of oxygen.

Answer 6

Pressurized air for the passenger and crew cabin comes from the compressor stages of the aircraft's engines.  It is AIR, not oxygen.  The emergency oxygen system is completely separate and has nothing to do with cabin pressurization.

The compressed air from the engine compressors is very hot and must be cooled by a cooling device that uses cold air from outside the airplane to cool the compressed air.  Then the compressed air is filtered and humidified, and mixed with the pressurized air in the cabin.  Cabin air is constantly circulated by ordinary fans.

To prevent the cabin from becoming over-pressurized, a small amount of cabin air is constantly bled off to the outside.  So the cabin really is NOT completely sealed.  Some air comes in, and some goes out.  The flow is balanced to maintain the proper breathing mixture and pressure.

Answer 7

It's actually not sealed.  Compressed air is pumped in from the outside into the cabin by the engines to the pressure altitude that whoever is responsible for that wants.  I believe it's actually all pumped in and the computer has to control how much to open the vents to bleed it out.

Answer 8

Quite scary but it is all recycled, on older planes it contains trace elements of used fuel vapours, ie it goes through the engines.

There was a recent case of a UK pilot blacking out due to this problem. it affects both Boeing and Airbus aeroplanes. Many cabin crew complain often of dizziness and headaches.

Source below: Source(s) http://www.californialung.org/spotlight/...

Airlines Use Recycled Air

Airlines use recycled air in the passenger cabins. Older aircraft tend to filter air and mix in fresh air before recirculating it in the cabin while most newer aircraft use almost all recycled air.

The air is extremely low in humidity and can dry out the mucous membranes in the nose, mouth, throat and bronchial tubes, which are then less able to keep out viruses and bacteria. Airline cabin air is also low in oxygen relative to fresh air on the ground. Healthy individuals shouldn’t notice a difference, but people with chronic lung diseases like asthma and emphysema might.

Most of the newer airplanes use system-wide HEPA filters that remove nearly all fine particles from the air, including airborne bacteria and viruses. But many older models don’t.