Pressurization Flashcards
Where is the position of the outflow valve displayed?
ECS synoptic page of MFD
The CPCS can operate in which modes?
Both manual and automatic
Which of the following are components of the CPCS?
Cabin Pressure Controller (CPC),
Cabin Outflow Valve (OFV),
Positive Pressure Relief Valve (Safety Valve),
&
Negative Pressure Relief Valve (NPRV)
The pressurization panel is found where?
Overhead panel
True or False: The basic function of the CPC is to modulate the outflow valve in order to maintain proper cabin pressure.
True
True or False: The CPC modulates the outflow valve based on information received from various aircraft sensors and systems.
True
True or False: The CPC is a quad channel controller.
False
[Dual = active and standby - manual modes of these allows for pilot manual pressure control]
True or False: If a CPC channel should fail, an EICAS message will be displayed.
True
The outflow valve _______ to increase cabin pressure and _______ to decrease cabin pressure.
Closes, opens
True or False: Normally, the outflow valve is modulated automatically by the CPC.
True
What is the proper way to increase cabin pressure while operating in the manual mode?
Rotate the Cabin Altitude selector knob to the down position
The Negative Pressure Relief Valve serves which purpose?
Prevents damage to the aircraft structure due to excessive negative differential pressure
The Negative Pressure Relief Valve is operated how?
Spring loaded
[-check valve - opens automatically based on pressure differential]
At which point will the Negative Pressure Relief Valve open?
If there is a pressure differential that exceeds -.5 psi between the cabin and the surrounding environment
True or False: The Negative Pressure Relief Valve requires no electricity to operate.
True
The Positive Pressure Relief Valve is operated how?
Spring loaded
[-check valve opens automatically based on pressure differential]
True or False: The Positive Pressure Relief Valve opens when the pressure
differential exceeds 8.6 PSI.
True
True or False: The Positive Pressure Relief Valve is connected to its own static port.
True
True or False: The Positive Pressure Relief Valve is installed to prevent damage to the aircraft structure due to excessive positive overpressure.
True
True or False: The Positive Pressure Relief Valve’s static port is not electrically heated, due to the fact that it does not protrude from the fuselage.
False
At which point would the Positive Pressure Relief Valve activate?
When differential pressure exceeds 8.6 psi
True or False: The Positive Pressure Relief Valve is located in the aft section of the aircraft (aft pressure dome).
True
True or False: DUMP cannot be used in the automatic mode to relieve pressure if needed. This is only done through manual mode.
False
[2.23 Vol 2 NOTE: “The Dump Function of the outflow valve is not available in Manual Mode. However if the button is pushed in, both recirculation fan and packs are turned off.”]
What information does the CPCS take into account when scheduling a target cabin altitude and cabin pressure variation?
Gross weight,
cruise altitude,
landing field elevation
True or False: The Negative Pressure Relief Valve only works if the Positive Pressure Relief Valve is operational.
False
What is the default Landing Field Elevation (LFE) value used by the CPCS if no
pilot input is made with the LFE knob when FMS field elevation is not available?
8,000 ft
True or False: When cruise altitude is not available from the FMS, the cabin
pressure schedule is based on ambient pressure.
True
True or False: The Negative Pressure Relief Valve works independently from the normal Outflow Valve.
True
In regard to the CPCS, what are the special procedures for high altitude
Operations?
There are no special procedures for high altitude operations
How is the DUMP function activated for the CPCS?
By pushing in the guarded DUMP button on the pressurization panel
What happens when the DUMP function is activated?
CPCS automatically: sets the packs and recirculation fans to OFF,
controls the outflow valve to maintain the cabin altitude rate of climb at 2000 ft/min up to 12,400 ft,
and closes the outflow valve at 12,400 ft allowing the cabin altitude to rise by natural leak
True or False: When the CPCS is in manual mode, no pilot input is necessary to adjust cabin pressurization.
False
What will occur if the cabin altitude reaches 9,700 ft.?
EICAS displays message CABIN ALTITUDE HI,
the aural warning “CABIN” is played on the flightdeck loudspeaker
Automatic mode for the CPCS has which of the following modes?
Ground,
Taxi,
Takeoff,
Climb,
Cruise,
Descent,
Abort
True or False: When the CPCS is in GROUND mode, the outflow valve is in the fully open position.
True
True or False: There is a pressurization ABORT mode in the event a return to field after takeoff is necessary.
True
What happens when the DUMP button is activated?
Sets the packs and recirculation fans to OFF (even in Manual Mode),
(If not in manual mode:) controls the outflow valve to maintain the cabin altitude rate of climb at 2000 ft/min up to 12,400 ft,
closes the outflow valve at 12,400 ft
The outflow valve is manually modulated by _______.
Manually adjusting cabin altitude with the CABIN ALT selector knob
True or False: The Negative Pressure Relief Valve works with a static port in order for it to function properly.
False
True or False: Cruise altitude entered in the MCDU has no effect on CPC pressurization calculations.
False
