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Cabin Pressure (2001)
IMDB rating: 3.60
Plot: A fully automated commercial jetliner is prepared to make its maiden voyage. Without an on-flight pilot, the craft relies on satellite linking for its course. But when the plane suddenly deviates from its determined route and establishes a circular pattern over Seattle, it becomes evident that the craft has been hijacked by a disgruntled former airline employee who has hacked into the flight’s computer system from his apartment, somewhere in the United States. Now, a former discredited Navy pilot and an oddball technician must race against the clock to find where the angry employee is, and regain control of the plane before it crashes into the city.
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Download Cabin Pressure
Directors: Simmonds Alan
Actors: Sheffer Craig,Rekert Winston,Pyper-Ferguson John,Low Jason,Lennarson Nels,Schell Neil,Muldoon Dan,Gray George,Thriller,Adventure,Drama,Action,
Did aircraft air-conditioning and pressurization system uses the same pipelines or duct…..?
before the conditioning air enter the cabin? or the conditioning air will pass through the pressure controller and then to the cabin or they are two separate system with weight penalty?
which ever come first either pressurize or air-cond
The short answer is YES. The conditioned air and the pressurization air is the same air.
—–EDIT—-
The air, under high pressure, is conditioned, and then enters the cabin as cooling/heating/pressurization air.
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On every jet that I have ever flown, some approximations of the following happens:
1) Some air is stolen from some stage(s) of the engines. Often there are two stages used, one for low pressure air (high power settings when there is plenty of air at the LP end of things), and another for high pressure air (low power settings when there isn’t much air, and we need all we can get).
2) The air passes through a pre-cooler. It is quite hot, I seem to remember around 500C when it comes off the engines. BTW, this is air before it enters the hot section, it is just hot because it has been compressed in a very serious way.
3) The air passes through a mass air flow control valve to keep the mass of air entering the cabin relatively constant.
4) The air enters the air cycle machine (ACM). This is an expansion turbine that cools the air. For a detailed explanation of this process, look on wiki.
5) The environmental system operates to keep the cabin in the correct temperature range by bypassing the ACM with some small amount of air, and mixing it back in with the cold air in the mixing chamber.
6) In some airplanes, trim air (more hot air that is destined for a particular zone in the aircraft) is added downstream.
7) All of this air is now pressurizing the cabin. There is no other air! There might be, in some airplanes, electric heaters is selected spots, but usually not. The hot, cold, and pressurization air is all the same thing.
On modern airplanes, there is some recirculation of air to conserve fuel. This is done by recirculation fans that gather a small amount (I think it is 20%, but don’t quote me) of "used" air from under the deck, and push it back into the mix manifold.
9) The pressure in the cabin is controlled by the pressurization controller(s), and they do their magic by modulating the outflow valve. In other words, try to keep the airflow in somewhat constant, and control the rate of outflow.
BTW, you can probably see the outflow valve on B737s and B757s from the gate area. It is around and below the left aft entry door.
RickH | Nov 18, 2009
I see airline disasters looming!
Krysoprase | Nov 18, 2009
The two systems are seemingly connected. However, they are seperate. The pressurization system does just that. Pressurizes the cabin air by squeezing in outside air. A/C system simply conditions that air. It will condition the air, regardless of pressure. The weight penalty cannot be overcome with current technology.
walkerml1973 | Nov 18, 2009
Yes and no.
The source of the pressurized air is the engine bleed air. This is very hot (from compression) so it goes through an air conditioning system to ensure it is the right temperature for the cabin.
The pressurization system actually controls how much air is escaping from the aircraft, by the use of outflow valves. So the air conditioning and pressurization ’systems’ are separate, but the pressurized air for both comes from the same source…
calnickel | Nov 18, 2009
