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At what cabin altitude is ECAM EXCESS CAB ALT triggered
9,550 ft
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Automatic pressurization law
• CPC uses:
• Pressurization schedule:
- Ground (before takeoff and 55 s after landing)
Outflow valve opens fully to ensure that there is no residual cabin pressure
- Take Off, CPC pressurizes at ΔP 0.1 PSI to avoid a pressure surge at rotation.
- Climb, Cabin altitude varies according to a fixed pre-programmed law that takes into account the aircraft’s actual rate of climb.
- Cruise, Cabin altitude is kept at level off value, or at landing field elevation, whichever is higher.
- Descent:
. Cabin rate of descent computed in order to get cabin pressure equal to landing field pressure +0.1 PSI shortly before landing
. Maximum descent rate is 750 ft/min
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Cabin Pressure Controllers
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Components of the Pressurization system
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Components of the Avionics ventilation system
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Conditions for an automatic transfer of CPC
An automatic transfer occurs:
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Describe the Packs operation
The removal of energy during this process reduces air temperature, resulting in very low air temperature at turbine discharge.
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ECAM BLEED Page, Packs indications
From top to bottom: • Outlet temp • Bypass Valve position • Compressor Outlet temp • Flow
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Amber HOT AIR Fault light
• Fault light comes ON when:
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Amber Pack Fault light
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Pressurization operation
• Automatic Operation:
• Manual Operation, Cabin altitude is controlled via the manual motor of the outflow valve by operating a switch on the pressurization control panel
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Pressurization Safety Valves
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RAM AIR inlet flap logic
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RAM AIR operation
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Residual cabin pressure
Red light flashes close to door window when:
Both engines are stopped and Slides are disarmed
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Residual Pressure Control Unit
Residual Pressure Control Unit (RPCU) automatically opens the outflow valve on ground in case of abnormal residual pressure when:
• Both CPCs are failed, or manual mode is selected and• The aircraft is on ground and
• All engines are shutdown or all ADIRS indicate an airspeed below 100 kt.
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Under which condition, Hot air pressure regulating valve close automatically
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Under which condition, Pack Flow Control Valve close automatically
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Amber Ventilation Blower Fault light
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Amber Ventilation Extract Fault light
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Ventilation operation
• On ground:
- Before application of TO power, ventilation system is in open circuit configuration (closed configuration when skin temperature is low)
- After application of TO power, ventilation system is in closed circuit configuration
• In Flight, ventilation system is in closed circuit configuration
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Ventilation, Blower/Extract on OVRD
• Either pushbutton on OVRD:
‐ System goes to closed circuit configuration
‐ Air conditioning air is added to ventilation air (blower fan stops if BLOWER P/B is OVRD)
• Both pushbuttons on OVRD:
‐ Air flows from air conditioning system and then overboard
‐ Extract fan continues to run
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Air Conditioning System Controler Fault
• 1 Lane fails: no effect
• 2 Lanes fail:
- Pack is lost
- Hot air pressure regulated and trim air valve close
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Air Conditioning System Controller / Pack Controller operation
• Each Air Conditioning System Controller / Pack Controller regulate the temperature by: