Aircon And Pressurisation Flashcards
Max cabin altitude
8000ft
When are bleeds off?
TKOF and LDG
Normal cabin pressure differential
5.5psi +- 0.3psi
Max cabin pressure differential for TKOD and LDG
0.5psi
How much can the FA vary temp using the bias controller?
Full control
Which component is bypassed when using the manual temp mode?
Auto temp controller
Procedure fit correct emergency Ram ventilation?
Recirc - fan off
Bleeds - min/off
AUTO/MAN/DUMP - manual
Manual knob - full clockwise
Forward out flow valve - open
What three factors does the pressurisation system depend on?
Inflow of air
Sealed vessel
Metered outflow of air
If pressurisation controlled manually, which way do you turn the knob to decrease cabin altitude?
Counter clockwise
Manual increase know it turned which way to decrease cabin altitude?
Counter clockwise
Which valve is actuated when selecting a cooler compartment via the air divert switch?
Divert valve
Can the forward outflow valve be opened on the ground?
No
What is the difference between the forward outflow selector and the manual increase knob?
They both open the forward outflow valve
But manual increase knob allows a modulated opening
How do you change from fully auto mode to semi auto mode for the pressurisation system?
Cabin Set/Norm switch to Cab Set
Under normal conditions what position should the bleed flow selector knob be in?
Max
Can the flight compartment fan be switched on in flight?
No
When electrical power is first applied to the aircraft, the pressurisation fault light illuminates for how long?
2 seconds
At FL250, what should the cabin altitude read? (Max cabin Altitude)
8000ft
If you land with the cabin below destination elevation the rear outflow valve opens to allow the cabin to climb at?
600fpm
What happens to the rear outflow valve upon touchdown?
It opens
What does the fault light indicate in the pressurisation panel?
Pressurisation computer is experiencing a fault or is conducting a self test.
Cooling for the avionics is provided by?
The avionics and cabin recirculating fans
Does the pressurisation toggle switch have to be in manual for the manual increase knob to work?
No
What voltage is required for bleed 1 and 2 switches to operate?
28v DC to the left and right main buses
Four modes of operation for the pressurisation system?
Fully automatic
Semi automatic
Manual
Dump
The CABIN DUCT HOT caution light causes which valve or set of valves to drive to full coil position?
Pack temperature control valves
What is the cabins rate of change with the rate knob at its index?
500fpm up
300fpm down
What automatic feature is associated with the AIR CON PACK HOT caution light?
All engine bleeds to the pack shut off
How can smoke be evacuated from the cabin?
Norm/Cab know set to Cab
Select a higher cabin altitude
Or select the rear outflow valve to dump using Auto/Man/Dump switch
What are the five components that require bleed air to operate?
Cabin door seals
De ice boots
Air conditioning and heating
Pressurisation
Rear outflow valve
If a cooler cabin temp is selected. The ACM pack bypass will?
Close
The AIR COND PACK HOT caution light excess temp is being sensed?
Compressor discharge over temperature sensor
If operating with only essential services, how can the aircraft be de pressurised?
Forward outflow valve must be used.
The forward and rear outflow valves are set to relive pressure automatically at what psi?
5.8 psi +- .15
How would you utilise the pressurisation system to remove smoke from cargo area?
Norm/Cab switch set to Cab
Select a higher cabin altitude or
Select rear outflow valve to dump using Auto/Man/Dump switch
If the left and right secondary busses fails how will the high pressure valve and PRSV position themselves?
High pressure valve closes
PRSV opens
Can cabin crew select cabin temp in the “manual mode” which the flight compartment temp controller is in Auto mode?
Yes
Are both outflow valves capable of automatic pressure relief at 5.8PSI +- .15?
Yes
Will the aircraft pressurise with bleeds off?
No
How is the rear outflow valve powered?
By suction created by the 18psi Denice system air flowing through a Venturi.
What happens when a BLEED HOT caution light illuminates?
That bleed is shut off
What does I mean when the CABIN PRESS warning light illuminates?
Cabin altitude has exceeded 10,000ft
What occurs when the pressurisation toggle switch is selected to Auto?
Rear outflow valve is controlled by the pressurisation computer
What occurs when pressurisation toggle switch is placed in the Dump position?
Rear outflow valve opens fully
A FLT COMPT DICT HOT caution light causes which set of valves to drive to full cool position?
Trim valves
How would you remove smoke from the cockpit?
Manual increase know increased or
Forward dump valve to open
What % of conditioned air does to the flight deck?
30%
What does the MIN/MAX rheostat on the bleed control panel do?
Adjusts the amount of air flow to the ACM
Will heat/air conditioning/pressurisation still be available if the main buses are not energised?
Yes, bleed valves will fail in the open position.
Why should the forward outflow valve be slightly opened before selecting the toggle switch to “Manual” when transitioning from Auto?
To prevent a pressurisation dump
The CABIN DUCT HOT caution light illuminates at?
88 degree C
What is the position. Of the rear outflow valve when A/C is on and aircraft is in the ground with engine bleeds on?
Open (Because we are on the ground)
Can pressurisation be maintained with only one bleed source available?
Yes
Is the cargo area pressurised?
Yes
What happens when the pressurisation toggle switch is selected to Manual?
Rear outflow valve closes. Pressurisation is then accomplished by modulating the forward outflow valve
Can all systems operate with only one bleed air source available?
Yes
