Q-PRESSURIZATION Flashcards
Will aircraft remain pressurized if one of the air-conditioning pack is turned off ?
Yes
How do you set up pressurization controller for automatic mode ?
Select AUTO and FWD OUTFLOW closed then set your destination and field altitude.
Which Outlfow Valve is used during automatic mode ?
AFT outflow valve
when would you use manual pressurization ?
if the auto mode fails
How is manual pressurization operated ?
Cabin Alt to MAN and adjust the cabin diff using the MAN DIFF switch
What is takeoff memorization mode ?
aircraft remembers field elevation for up to 10 min after departure .
When is takeoff memorization mode cancelled ?
when the aircraft is less then takeoff altitude plus 5000 feet
What does the forward outflow safety valve do ?
allows for flight compartment smoke evacuation and ram air ventilation
When does the CABIN PRESS warning light illuminate ?
When cabin ALT is more the 9800 feet cabin alt
What is the AFT safety valve used for ?
Helps in depressurization during normal mode
How is the AFT valve opened and closed ?
Electrically
How is the forward outflow valve open and closed ?
Manually and uses suction and springs
What does the environmental system provide ?
Heat, cooling, vent, pressurization.
What is the permitted position of the bleeds for takeoff ?
MIN
What indication is on the ED when the bleeds are on and the bleed selector is set to NORM with NTOP ?
Bleed ( Amber )
What indication on the ED with MTOP and bleeds on ?
MCP and no indication of bleeds.
What does selecting the rear outflow valve switch to DUMP do ?
Releases the pressure by fully opening the valve.
What happens when you turn the rear outflow valve controls switch to MAN ?
Turn off the cabin pressure controller
Enables the use of the manual control outflow valve and the cabin diff pressure using the manual MAN DIFF switch.
What does the forward outflow valve do when closed ?
Decreases the cabin altitude by closing the forward safety valve.
What does the forward outflow valve do when closed ?
It decreases the cabin altitude by closing the forward safety valve.
What is the forward safety valve ?
Used for emergency operations.
Normal the valve is closed
Open the valve is fully opened.
How is the pressurization system tested ?
When electrical power is added, the system runs a self test and a FAULT alert light in the Cabin Pressure Control Panel will light up. If the light stays on there’s the a problem in the system.
What modulates the aft outflow valve ?
Pre programmed cabin pressure controller
What prevents the airplane from pressurizing on the ground ?
The aft valve is fully open when power levers are at less then 60 degrees.
Also, if one engine is running idle or APU is running.
What is the purpose of pre pressurization ?
To avoid cabin pressure bump during take off.
The cabin altitude is set to 400 below the takeoff altitude at a rate of 300ft/min
This allows for the aft outflow and aft safety valve to fully closing if a takeoff so made with the bleeds off.
What is take off abort mode ?
The CPC is in take off mode for 10 Min after lift off, this avoids having to re set the landing altitude during an emergency return.
As long as the scheduled cabin altitude then the theoretical cabin altitude, or the airplane altitude is less then take off altitude +5000 ( valid only for takeoffs above 8000 feet )
after this the CPC begins scheduled pressurization
How is emergency ventilation achieved with no active bleed air ?
through the NACA vents that allows ram air into the cabin and the flight compartments and then out the forward outflow valve.
what is the maximum cabin diff permitted by the CPC ?
5.46
what happens if diff pressure reaches higher then 5.8 +/_ 0.15 PSI ?
a pressure limiter in both the forward and aft safety valve open to release the pressure.
what is indicated on the ED with the bleed selector switch set to MIN and NTOP or MTOP is set ?
bleeds in (white)
Aaa
.
Normal pressure diff ?
5.46 =/_ 0.1
Max cabin presaure dif limit
5.95
Max cabin dif durring taxi
0.5
Max cabin altitude ( pressurized)
8,000 ft
What is the purpose of the aft safety valve ?
to prevent pressurization on the ground
Auto mode what is the rate of climb ?
580-1010
