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 = 64F 12 o’clock=76F HOT=86F
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 is Delta Press is less than 1.0 psi. Basically, you need to descend.
When should you select ECON FLOW ON on the A321?
When passenger count is < 140. IT reduces pack flow up to 20%
- 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 mixing unit air.
How are the zone temperatures individually controlled?
Pack operation is controlled by air conditioning system controller signals.
What controls the packs and TAVs?
- 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.2. If remains closed on the starting engine side (provided the crossbleed valve is closed) when:a. MASTER SW onb. Start valve is openc. N2 <50%3. On the ground, reopening of the valves is delayed for 30secs to avoid a supplementary pack closure cycle during 2nd engine start.
What happens to the system during engine start?
- 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.
What happens when a duct overheat occurs?
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.
When does the Pack Ram Air Inlet Flap close?
- In single-pack operation- When the APU is suppling bleed air- When temperature cannot be satisfied
What 3 conditions could cause the Pack Flow to be Higher than the selected on the overhead panel?
18 – 30 degrees Celsius (64 – 86 degrees Fahrenheit)
The compartment temperature controllers can be set to what range of temps?
No effect, as the second lane takes over.
What happens if an ACSC has a LANE failure?
Related pack is lost (ACSC1 – flight deck, ACSC 2 – cabin), Hot Air Pressure Regulating Valve and associated Trim Air Valves close.
What happens if an ACSC has a double LANE failure?
When the temperature drops < 70 degrees and the flight crew selects OFF.
When does a Pack Overheat FAULT light, (on OHP) extinguish?
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 happens when the Ram Air Pushbutton is selected ON?
Only open if differential pressure is lower than 1 PSI.
What limitations apply to the opening of the Ram Air Valve?
A320 LO: if the number of occupants is below 141. A321 ECON: if the number of occupants is below 168.
The LO/ECON pack flow setting thresholds.
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 OPEN 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 CLOSED configuration?
In very hot climates (>90F), the extract valve is partially open during TO until colder ambient conditions are reached.
What is the intermediate configuration?
Avionics Equipment Ventilation Computer (AEVC)
What controls the Avionics ventilation system?
Cargo heat is disabled, we do not carry pets!!
What is unique about out cargo compartments?
The valve position does not agree with the commanded position.ORThe valves are in transitORSkin temp between 8-12C
Why would the inlet and extract valves be amber?
Blower fan low pressureDuct overheatComputer power supply failureAvionics smoke
When would a BLOWER fault illuminate?
Extract fan low pressureComputer power supply failsAvionics smoke
When would a EXTRACT fault illuminate?
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 happens when you press OVRD on the BLOWER or EXTRACT pb
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 is the serious in-flight failure in regards to avionics
MASTER CAUTSMOKE light on GEN ! LINEFAULT on both BLOWER and EXTRACTAVNCS SMOKE message
What indicates smoke int he avionics bay?
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 High Skin Air temperatures, which Config is in operation?
The closed-circuit configuration operates when skin temperature is beneath the on-ground threshold.Avionic bay – heat exchanger – cargo underfloor
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 in flight threshold of +35 degrees to +32 degrees.Heat exchanger – cargo
In the “Flight” Mode at Low Skin Air Temperatures which Config is in operation?