Air Conditiong/Ventilation/Pressurization Flashcards
What computers monitor and control the pneumatic system?
2 Bleed Monitoring Computers (BMC)
If one BMC fails, can the other take over?
Yes
The PACK FLOW selector has LO, NORM, and HI positions. What is the rule of thumb for setting?
LO: Occupants below 138
HI: For abnormally hot and humid conditions
NORM: For all other operating cases
What modulates the trim air valves?
The zone regulator adjusts the trim air valves and pack outlet temps to optimize the zone temps
How are the Pack Control Valves controlled and regulated?
Pneumatically operates and electrically controlled by the pack controller
What is the purpose of the Emergency Ram Air Inlet?
- cabin ventilation in case both packs are inop
- clear smoke out of the cabin
What happens when the RAM AIR pb is selected to ON?
- ram air valve opens, and
- outflow valve will fully open when cabin differential pressure is less than 1 psi (as long as the cabin MODE SEL pb is in AUTO)
- the emergency ram air inlet and outflow valve will not open if ditching has been selected
What do the Pack Flow Control Valves do?
- regulate amount of bleed air supplied to the packs
- function as shut off valves
When will a Pack Flow Control Valve automatically close?
- during engine start
- upstream pressure below min
- pack overheat
- pressing an ENG FIRE pb
- ditching pb selected ON
What does the the Hot Air Valve do?
Controls supply of hot bleed air to all 3 Trim Air Valves
What do the Trim Air Valves do?
Add hot air to airflow from mixing unit to maintain selected zone temperatures
How are the Trim Air Valves controlled?
Electrically by the zone controller
What happens if the primary channel of the Zone Controller fails?
- Hot Air valves close
- Trim Air valves close
- Lose flow function
- Lose optimized temperature
What would cause an amber PACK FAULT light to illuminate?
- Pack overheat
- Switch position disagreement with pack FCV
What does the amber FAULT light in the APU BLEED pb indicate?
Bleed leak
What causes the amber FAULT light on the ENG BLEED pb?
LOOSA
- Leak
- Overpressure downstream
- Overheat
- Starting engine and valve not closed
- APU bleed on and valve not closed
What happens if both the primary and secondary channels of the Zone Controller fail?
- optimized and back-up temp regulation is lost
- Pack 1 delivers a fixed temp of 68* F
- Pack 2 delivers a fixed temp of 50* F
What logic controls the X-BLEED valve when the X-BLEED switch is in AUTO?
- When APU BLEED valve is OPEN, the X-BLEED valve is open
- When the APU BLEED valve is CLOSED, the X-BLEED valve is closed
What is the function of the HOT AIR pb?
- The HOT AIR valve controls the supply of the hot air to all of the trim air valves which maintain the selected temperature in each zone
- Valve position is controlled by the HOT AIR pb. The valve automatically closes in the event of a fault
What does the amber HOT AIR FAULT light indicate?
Duct overheat; the HOT AIR valve closes automatically
How does the system optimize the temperature in each of the three zones?
- Trim air valves
- To maintain the selected zone temperature, the trim air valves under control of the zone regulator, add hot air, if necessary, to the air flowing from the mixing unit
- This allows the air temp to be controlled independently in each zone
What effect will the engine start sequence have on the pack flow control valves?
The pack flow control valve will close automatically
After engine start with the APU BLEED pb ON, what source is supplying bleed air to the packs?
APU Bleed
What does the DITCHING pb do?
Closes all the valves below the waterline: CARPO
- Cargo compartment isolation valves*
- Avionics ventilation (inlet/extract valves)
- Ram air inlet
- Pack FCVs
- Outflow valve (if in AUTO)
*only forward cargo valves close; aft cargo valves duct out of outflow valve
With the BLOWER and EXTRACT pb’s in AUTO how does the system typically operate?
- Ground: system is in OPEN config
- Flight: system is in CLOSED config
- Intermediate: closed except extract valve is partially open
With the BLOWER and EXTRACT pb’s in OVRD, what are the positions of the INLET and EXTRACT valves?
Smoke configuration:
- INLET valve closed
- EXTRACT valve open
- A/C is introduced into the avionics compartment
Which fan is off when the BLOWER and EXTRACT valves are in OVRD?
- BLOWER fan is off
- EXTRACT fan is on
Is air conditioning ever introduced into the avionics compartment?
Yes, in the smoke config or abnormal config
What does the FAULT light on the BLOWER pb indicate?
- SMOKE warning is activated
- Computer failure
- Low blower pressure
- Duct overheat
What does the FAULT light on the EXTRACT pb indicate?
- SMOKE warning is activated
- Computer failure
- Low extract pressure
With 2 FAULT lights on the VENTILATION panel are there any other indications?
Yes, the SMOKE light in the GEN 1 LINE pb
When do the cabin oxygen mask doors automatically open?
When the cabin altitude exceeds 14,000 feet
Can you manually deploy the masks?
Yes, lift the guard and press the MASK MAN ON pb
What does the PASSENGER SYS ON light mean?
The signal to release the oxygen mask doors has been sent either automatically or manually
What method is used to supply passenger cabin supplemental oxygen?
Chemical generators
How long does the PAX oxygen last?
Approximately 15 minutes
Where is oxygen stored for the crew?
In a single high-pressure cylinder
What happens during the preflight when you push to extinguish the CREW SUPPLY OFF pb?
It opens a valve in the avionics bag to supply low-pressure crew oxygen
What would you notice on the DOOR ECAM when turning on the crew oxygen?
The OXY would change from amber to green
On the ground, what does an amber half frame under the pressure mean?
Pressure is less than 1500 psi
How do you deactivate the crew oxygen mask microphone after use?
Close the left door and press the PRESS TO TEST AND RESET switch
Where do you find the minimum flight crew O2 values?
FCOM LIM-35
Can the pilot control the outflow valve?
Yes, select MAN on the MODE SEL and use MAN V/S CTL switch
How many auto pressure controllers?
2
Only one controller operates at a time and automatic transfer occurs:
-70s after each landing
-If the operating system fails
How do you manually switch controllers?
Switch MODE SEL to MAN for 10 sec, then back to AUTO
What does an amber FAULT light in the MODE SEL pb indicate?
Both automatic pressure controllers are faulty
The LDG ELEV selector in the AUTO position does what?
The pressurization system uses the FMGS data to construct an optimized pressurization schedule
Where does the pressurization system obtain the landing elevation from?
FMGC Database
When out of the AUTO position, what is different?
The pressurization system uses the manually selected landing elevation
