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vhqpa
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What Is This A320 Flap? (pic)

Sun Nov 30, 2008 5:21 am

Hello I flew out of MCY the other day waiting for my delayed flight I noticed a JQ 320 depart with a small flap open just below the aft starboard door. Ive never noticed this before can anyone shed some light onto this? here is the picture below








Vhq

[Edited 2008-11-29 21:23:12]
"There you go ladies and gentleman we're through Mach 1 the speed of sound no bumps no bangs... CONCORDE"
 
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Starlionblue
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RE: What Is This A320 Flap? (pic)

Sun Nov 30, 2008 6:03 am

Outflow valve open I think.
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ovrpowrd727
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RE: What Is This A320 Flap? (pic)

Sun Nov 30, 2008 6:47 am

it helps maintain cabin pressure on the ground
 
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HAWK21M
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RE: What Is This A320 Flap? (pic)

Sun Nov 30, 2008 7:26 am

The Main Outflow valve that modulates to mantain Cabin pressure.
regds
MEL
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SB
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RE: What Is This A320 Flap? (pic)

Sun Nov 30, 2008 5:46 pm



Quoting Ovrpowrd727 (Reply 2):
it helps maintain cabin pressure on the ground

I think you mean in the air  Wink It will be fully open on the ground to depressurize the aircraft.

S.
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David L
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RE: What Is This A320 Flap? (pic)

Sun Nov 30, 2008 5:54 pm



Quoting NKP S2 (Reply 4):
Quoting Ovrpowrd727 (Reply 2):
it helps maintain cabin pressure on the ground

Bad answer.

Well, it "maintains" cabin pressure on the ground rather than letting it increase, doesn't it? If it were closed, the cabin pressure would be much higher than the ambient pressure on the ground. In other words, it'll be wide open when on the ground and gradually close as the ambient pressure drops at higher altitudes... no? You can "maintain" pressure by preventing it from rising as well as by preventing it from falling.

I think I might have called it an incomplete answer rather than a "bad" answer.  Smile
 
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HAWK21M
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RE: What Is This A320 Flap? (pic)

Sun Nov 30, 2008 8:37 pm

Is that a single gate? Any reason why the A320 stuck to the Single gate rather than the dual gate common in current boeing models.
regds
MEL...
I may not win often, but I damn well never lose!!! ;)
 
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vhqpa
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 5:02 am

Thank you all for your answers.

Is the main outflow valve supposed to be open for take off?





Vhq
"There you go ladies and gentleman we're through Mach 1 the speed of sound no bumps no bangs... CONCORDE"
 
Airbus_A340
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 10:21 am

We have two outflow valves on the A340, one on the FWD belly of the fuselage, and one in the AFT belly.

Both outflow valves on the A340 close slightly when the take-off is initiated, I'm assuming a similar logic applies to the baby-bus. The System controllers close them slightly to prevent a pressure surge on rotation.
 
David L
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 11:35 am



Quoting Vhqpa (Reply 8):
Is the main outflow valve supposed to be open for take off?

On the ground the cabin pressure is already at the ambient pressure so if you force in high pressure air from the engines and don't release it, the cabin pressure will be much higher than you want/need. At altitude, where the ambient pressure is much lower than is desired in the cabin, the outflow valves will close to allow the air being forced in to build up the pressure you need to make the air breathable and more comfortable.

Generally speaking, as the valves close, the cabin pressure will rise above the ambient pressure and as they open, the cabin pressure will drop towards the ambient pressure.

Quoting Airbus_A340 (Reply 9):
Both outflow valves on the A340 close slightly when the take-off is initiated,

To seat any plug-type doors against the seals, I assume.
 
PhilSquares
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 11:44 am



Quoting HAWK21M (Reply 7):
Is that a single gate? Any reason why the A320 stuck to the Single gate rather than the dual gate common in current boeing models.
regds
MEL...

The 320 has a single outflow valve. It is controlled by 3 different motors (two for automatic operation and one for manual operation, there are also two Cabin Pressure Controllers (CPC) which generally operate their associated motor. There are two safety valves and one contol panel
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Airbus_A340
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 12:39 pm



Quoting David L (Reply 10):

To seat any plug-type doors against the seals, I assume.

I'm sure that's the case too, the manual says it's to prevent a pressure surge on rotation.
Good explanation r.e. the function of the outflow valves.
 
David L
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 2:12 pm



Quoting Airbus_A340 (Reply 11):
Quoting David L (Reply 10):

To seat any plug-type doors against the seals, I assume.

I'm sure that's the case too, the manual says it's to prevent a pressure surge on rotation.

Ah, there had to be more to it than my explanatiuon.

Quoting Airbus_A340 (Reply 11):
Good explanation r.e. the function of the outflow valves.

Thanks. When one talks as much hot air as I do, one learns a thing or two about how it behaves.  Smile
 
access-air
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RE: What Is This A320 Flap? (pic)

Mon Dec 01, 2008 8:53 pm

These are also visable on the DC10 and DC9 series...

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