Air Conditioning and Ventilation Flashcards
Each of the 2 AC Controller is divided up into…
2 Lanes
What happens to the PACKs during TO and Landing?
The inlets and outlet close to prevent FOD
How is PACK air temp regulated?
Throttling the Bypass Valve warms the air with hot air bypassed from the primary HE
What does the valve icon on the BLEED status page represent?
The bottom valve is the Pack Flow Control Valve position. The upper valve is the Bypass Valve position
What regulates the different zone temperatures?
The addition of bleed air warms compartments that are required to be warmer than the coldest set compartment.
What is the purpose of the recir fans?
By recirculating the air, bleed air demand is reduced leading to fuel savings
Why would the mixing unit line at the top of the BLEED page be amber?
Pack flow control valves and ram air inlet are closed
Why would you receive a FAULT Pack fault light?
Pack flow control valve disagrees with commanded position, Pack compressor overheat, Pack outlet temperature overheat (note: valve closes auto during an overheat condition)
What are the extreme and middle temperature settings on the control knob
COLD = 18C
12 o’clock=24C
HOT=30C
What does the FAULT on the HOT AIR pb indicate?
Duct overheat
What if you see PACK faults during pre-flight?
This is normal, indicating that there is not enough bleed air pressure for the packs until the APU or Engine Bleed is opened.
Your aircraft has less than 115 people, what Pack Flow setting should you set?
LO, to conserve fuel
You select the RAM AIR to open but it does not react as commanded, why?
The valve will only open if Delta Press is less than 1.0 psi. Basically, you need to descend.
When should you select LO on the PACK FLOW selector?
When passenger count is < 168.
IT reduces pack flow up to 20%
How are the zone temperatures individually controlled?
- Temperature regulation is controlled by 2 air conditioning system controllers.- Temperature regulation is optimized via the hot air pressure regulating valve, and the trim air valves that add hot air, tapped upstream of the packs, to the air coming from the mixing unit.
What controls the packs and TAVs?
Pack operation is controlled by air conditioning system controller signals.
What happens to the system during engine start?
- If the crossbleed valve is closed, the valve located on the staring engine side immediately closes, when the mode selector is set to IGN or CRANK.
- It remains closed on the starting engine side (provided the crossbleed valve is closed) when:
a. MASTER SW on
b. Start valve is open
c. N2 <50% - On the ground, reopening of the valves is delayed for 30 secs to avoid a supplementary pack closure cycle during 2nd engine start.
What happens when a duct overheat occurs?
- The FAULT light come son amber.- ECAM caution, when duct overheat is detected.- The fault circuit detects an overheat when the duct temperature reaches 80 degrees once.
When does the Pack Ram Air Inlet Flap close?
T/O: takeoff power is set and the main landing gear struts are compressed.
LDG: as soon as the main landing gear struts are compressed, as long as speed is greater or equal to 70kts. They open 20sec after speed drops below 70kts.
What 3 conditions could cause the Pack Flow to be Higher than the selected on the overhead panel?
- In single-pack operation
- When the APU is supplying bleed air
- When temperature cannot be satisfied
The compartment temperature controllers can be set to what range of temps?
18 – 30 degrees Celsius
What happens if an ACSC has a LANE failure?
No effect, as the second lane takes over.
What happens if an ACSC has a double LANE failure?
Related pack is lost (ACSC1 – flight deck, ACSC 2 – cabin), Hot Air Pressure Regulating Valve and associated Trim Air Valves close.
When does a Pack Overheat FAULT light, (on OHP) extinguish?
When the temperature drops < 70 degrees and the flight crew selects OFF.
What happens when the Ram Air Pushbutton is selected ON?
If the DITCHING p/b, on the CABIN PRESS panel is in normal position:
- Ram Air Inlet opens
- If delta P is greater or equal to 1 PSI, no emergency Ram Air flow in (Closed)
- If delta P is less than 1 PSI, outflow valve opens to 50% when under automatic control. It does not automatically open when it is under manual control. Emergency RAM airflow is directly supplied to the mixer unit.
What limitations apply to the opening of the Ram Air Valve?
Only open if differential pressure is lower than 1 PSI.
The LO pack flow setting thresholds.
LO: if the number of occupants is below 168.
What is the OPEN configuration?
In warm ambient climates (>50F), the blower motor takes outside air, blows it over the avionics and discharged by the extract fan and valve..Both blower and extraction valves are OPEN
What is the CLOSED configuration?
In cold ambient climates (<50F), the blower and extract fans operate when the valves are closed, circulating air from inside the fuse only.Both blower and extraction valves are CLOSED.Condition after TOGO power, in-flight to landing
What is the intermediate configuration?
In very hot climates (>90F), the extract valve is partially open during TO until colder ambient conditions are reached.
What controls the Avionics ventilation system?
Avionics Equipment Ventilation Computer (AEVC)
What is unique about our cargo compartments?
Cargo heat is disabled, we do not carry pets!!
Why would the inlet and extract valves be amber?
The valve position does not agree with the commanded position
OR
The valves are in transit
When would a BLOWER fault illuminate?
Blower fan low pressure
Duct overheat
Computer power supply failure
Avionics smoke
When would a EXTRACT fault illuminate?
Extract fan low pressure
Computer power supply fails
Avionics smoke
What happens when you press OVRD on the BLOWER or EXTRACT pb
The blower or extract fan stops and air conditioned air is introduced.Note: In normal conditions, the bay is cooled by the skin heat exchanger to save fuel.
What is the serious in-flight failure in regards to avionics
Extract valve opens in flight which can compromise pressurization.Note: In inlet duct has a non-return valve to present this if the inlet valve opens.
What indicates smoke int he avionics bay?
MASTER CAUTSMOKE light on GEN ! LINEFAULT on both BLOWER and EXTRACTAVNCS SMOKE message
In the “Ground” Mode at High Skin Air temperatures, which Config is in operation?
The open-circuit configuration operates when skin temperature is above the on-ground-threshold from +12 degrees to +9 degrees.Inlet valve – blower – avionics – extract – extract
In the “Ground” Mode at Low Skin Air Temperatures, how is the Circulatory Air now cooled?
The closed-circuit configuration operates when skin temperature is beneath the on-ground threshold.Avionic bay – heat exchanger – cargo underfloor
In the “Flight” Mode at Low Skin Air Temperatures which Config is in operation?
The closed circuit configuration operates when skin temperature is beneath the in flight threshold of +35 degrees to +32 degrees.Heat exchanger – cargo