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Old Sep 26th 2018, 04:59 PM   #1
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Air plane pressure

So I'm flying on a jet and I have to swallow to reduce the pressure in my ears and a thought occurred to me.

The jet is essentially a flying tube, sealed to maintain normal air pressure. But if it is sealed then how can the air pressure in the plane rise and fall?

Thanks!

-Dan
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Old Sep 26th 2018, 06:05 PM   #2
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My Guess!

At altitude (~30,000ft) the ambient outside aircraft pressure is about 6psi.
An air bleed from an engine compressor section to the craft interior
pressurizes the in-flight cabin to about 10psi... About typical flight
pressure.

There is no "pressure of the ear." There is a pressure outside acting on
the ear membrane (drum) via passage through the outer ear. Also a pressure
acts interior to the ear membrane. This pressure path passes through the nose, mouth then sinus passages interior to the head.

Upon a headache, when pressure one side of the drum differs from the other - blow your nose!

Just my thoughts ....
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Old Sep 26th 2018, 07:41 PM   #3
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Aircraft are not fully pressurised (to 15Psi) they want to keep the weight of the aircraft down ... just enough pressure to keep the passengers alive (12 to 11 psi ) with normal air , then the fuselage can be thin ...
If they had pure oxygen the fuselage could be even thinner .... astronauts live in 5psi pure oxygen.

Originally Posted by THERMO Spoken Here View Post
At altitude (~30,000ft) the ambient outside aircraft pressure is about 6psi.

There is no "pressure of the ear." There is a pressure outside acting on
the ear membrane (drum) ....
30,000ft =4.36 psi ....

I think it's true to say there is (over) pressure in the (inner) ear ...outside pressure is reduce , ear drum is pushed outwards when aircraft ascends ... pushed inwards when aircraft descends .
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Last edited by oz93666; Sep 26th 2018 at 07:44 PM.
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Old Sep 29th 2018, 10:18 AM   #4
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Originally Posted by topsquark View Post
So I'm flying on a jet and I have to swallow to reduce the pressure in my ears and a thought occurred to me.

The jet is essentially a flying tube, sealed to maintain normal air pressure. But if it is sealed then how can the air pressure in the plane rise and fall?

Thanks!

-Dan
There are other ways to normalize ear pressure. Just yawn with your mouth closed.
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Old Sep 29th 2018, 06:10 PM   #5
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gravity

Just imagine what's the reaction of the atmosphere if gravity of the earth vibrates...
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