ATA 21 - Air Conditioning / Pressurization / Ventilation Flashcards
What are the consequences of the primary channel failure in the zone controller ? Of the secondary channel ? Of both ?
Primary Channel: secondary takes over. Pack 1 for cockpit and pack 2 for cabin. 24 °C each. Hot air valve closed
Secondary Channel: no backup available
Both: 20°C pack1 and 10°C pack 2
What are the conséquences of a pack controller, primary channel failure ? secondary channel failure ? Both ?
Primary: pack flow fixed at the current setting
Secondary: backup lost
Both: Pack outlet temperature is controlled to between 5 and 30 deg C by the anti-ice valve
Bleed air supplied from the APU (APU bleed valve open), which pack flow is automatically selected ?
High
When does normal cabin air pressurization occur?
During take off roll
When does normal depressurization is completed ?
1 min after landing
Max altitude for Ram Air ?
10 000ft
Cabin pressure limitation with ram air utilisation ? Outflow valve position ?
Cabin differential pressure 1psi max. Outflow valve open at 50% if in auto mode.
General description of Air conditioning system ?
Cf diagram
Temperature corresponding to temperature selector COLD, NORM, HOT ?
18, 24, 30 °C
Description of a Pack ?
Cf diagram
Pack controller closes valve when :
- IGN / START ( closed until 2nd engine start or 30s)
- ENG FIRE PB
- DITCHING PB
- no air / overheat / overpressure
When pack air intake and outlet valves close ?
At take off
At landing (until < 70 kt + 20s)
Pack controller primary channel failure consequences ?
Works on secondary channel
Not optimized, previous flow is frozen
Description of avionic ventilation system ?
Cf diagram
How many cabin pressure controller are they ?
2, cycle every landings
Maximum cabin rate of descent ?
750 ft /min
Excess cabin altitude alarm at which altitude ?
9550 ft
No smoke, seat belt, Exit lights automatically ON at which cabin altitude ?
11300ft
Number of safety valves and max cabin pressure value ?
2 safety valves, 8,6psi
CPC 1 has a back up independent power supply. True / False ?
True
The lavatory/galley extract fan operates:
a.
Continuously when electrical power is available
b.
Only on the ground
c.
Only in flight
A
If bleed air is being supplied by the APU or if one pack fails; pack flow will go to what rate?
High
When either the BLOWER or EXTRACT switches are in OVRD; air from the air conditioning system is added to ventilation air. True or False ?
True
What is the number of occupants below which you select Pack flow LO ? A318,A319, A320,A321
A321: 168 (ECON)
A320: 141
A319: 138
A318: -
Following an ECAM CAB PRESS SYST 1 AMBER FAULT. SYSTEM 2 takes over automatically without crew action. True or False ?
True
During landing run PACK AIR FLAPS open when speed is less than XX kts ?
70kts + 20s
The cabin zone temperature sensors are ventilated by the air extracted by the lavatory and galleys extraction fans. True or False ?
True
The outflow valve is powered by how much electric motors ?
3
2 for auto control
1 for manual control
Consequence of a ACSC (Air Conditioning System Controllers) dual lane failure ? Of a single lane failure ?
Single Lane: none
Both : Pack lost and hot air reg press valve closes
If Pack flow is selected to LO and it is unable to cool down at the desired temperature, what does it do ?
NORM
In case the AC is equipped with Air System Controller (ASC) instead of zone + pack controllers, which ASC controls which zone ?
ASC1 = cockpit
ASC2= cabin
If bleed flow is too weak to sustain pack demand for cabin temperature, zone controller ask for higher IDLE. True or False ?
True
in case ECAM requires that during final app VS CTL …. FULL UP, at which altitude do you perfom the action ?
2500ft AAL
