what is the pressure and temperature inside a flying passenger aircraft. how it is maintained and its principl

Question

if pressure and temperature are different in an aircraft,than outside,then how these are adjusted while passengers come outside and get inside into an aircraft? Is it necessary to adjust these at each time of landing and take off?While flying above high altitude mountains what are the changes adjusted to these parameters?

Answer 1

Commercial Jet aircraft use a pressurized cabin that maintains
approximately 8,000 ft. This system is not active while
passengers board the aircraft.

Temperature is maintained,also as you lose 3 degrees for
every 1,000 feet of altitude. In Florida one spring morning, I heard
a pilot report from 41000 feet that the temperature outside was 40
degrees below zero.

Answer 2

Pressure and temperature varies. The excess air pressure created inside a jet engine is used to maintain an air pressure in the cabin that is confortable at various altitudes. The cabin of the aircraft is pressurized like an inflated balloon. Of course, there is only so much the engines can do. So, an aircraft cabin may be pressurized to equal the air pressure at 3000ft or 4000 ft and so on... This is called cabin pressure altitude. It does not matter how high or how low I am flying, the pressurization controller will maintain whatever cabin pressure altitude that I dial into the controller. My aircraft can maintain up to 6 psi of inside cabin air pressure. Should the pressure rise above 6 psi, there are valves that open up to allow excess pressure to vent off. (Try keeping your lips closed while you try to force air past your lips. At some point the air will escape. The tighter you clamp your lips, the higer the pressure in your mouth and vice versa.) They are called bleed valves. They can be adjusted by the pilot to open at a lower psi. PSI equates to pressure altitude inside the cabin.
I don't have to adjust this every time I take off or land. There are sensors on the landing gear that automatically activate the pressuization when I take off. (But, like I said before, I can adjust it if I please.) These sensors also allow all the excess cabin pressure to bleed off when I land. If the sensors malfunction, the pilots can bleed the air off by use of a manual dump switch. You don't want to know what will happen if the manual switch fails. Think of that balloon. Now prick it with a pin. When the doors are open the cabin pressure altitude is always equal to the outside altutude pressure. If you are in Miami, then the cabin pressure altitude will be equal to sea level. If you are in Denver, the cabin pressure altitude will equal Denver at 5280 ft.
The temperature on my aircraft is set automatically at around 65 degrees on the ground. This is the coldest that my aircraft air conditioner can cool the air. I have an a/c, like on your car. It only operates when the engines are running. Larger aircraft, have special smaller engines called auxilliary power units that run the air conditioner when the main engines are not running. The air conditioner cools the outside air that it draws inside by a fan/blower. The higher an aircraft flies, the cooler the outside air becomes and the less the air conditioner has to work. If I need warm air in the cabin, the air conditioner/heater will vent the hot air from the engines to the cabin. This engine air is cooled when the cool outside air is forced across the hot jet engine air radiator. The air comming from the jet engine is clean and uncontaminated. It's not like the dirty exhaust of a car or a piston engine. Because, cooler air fall, the cold air vents are located above my head in my aircraft. Hot air rises, so, the heater vents are located near the floor of my aircraft.
Does this answer your question?

Answer 3

Pressurization and air conditioning are based on compressed air taken from engines.
In cruise pressure is usually the pressure you can find at 2000m in mountains, because this is the minimum comfortable pressure, and temperature is usually about 20°C.
Pressure is regulated by a valve that controls the flow from cabin to outside, it's a dynamic equilibrium.
When airplane altitude is more than 2000m pressure is always the same, but when it's climbing or descending pressure changes(slower than outside) in order to avoid that pressure changing too fast can cause problems to passengers' ears.

Answer 4

It is pressurized and heated/cooled by the air conditioning system. This system uses the bleed air from the aircraft engines to turn the A/C compressor turbines. That air pressure from the A/C turbine is either cooled or heated to maintain the temp, while an outflow valve maintains correct pressure.

Answer 5

Hi,
For your Question Answer is Depending on How deep you want to know, Because it involves more then one system.
I suggest visit http://www.boeing-727.com then you will get a good understanding about how this
systems works(aircon,pressur,pneumatics)etc.
Good luck.

Answer 6

................ MAX. PRESSURE . EQUIV. TO 8000 FEET ABOVE SEA LEVEL [ by law ] .................. LIKE IN A TUBE BY PUMPING COMPRESSED AIR PRESSURE IN IT.... ..AND MAINTAINING IT ............. EITHER BY COMPUTERS......... OR MANUALLY ........... THE LANDING FIELD DATA HAS TO BE PROVIDED .......... AUTO OR MANUALLY .....................