AIR COND/PRESS/VENT 1.21.

10 P1
Contents
A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 17

GENERAL
The air conditioning system is fully automatic.
It provides continuous air renewal and maintains a constant selected temperature in nine aircraft zones
: One in the cockpit, and eight in the cabin.
Air is supplied by the pneumatic system, via :
– Two pack flow control valves,
– Two packs,
– The mixing unit, which mixes air coming from both the cabin and the packs.
It is then distributed to the cockpit and the cabin.
Temperature regulation is optimized via two hot air pressure regulating valves and the trim air valves
that add hot air bled upstream of the packs to the mixing unit air via the two hot air manifolds.
In an emergency, a ram air inlet can provide ambient air to the mixing unit.
Temperature regulation is controlled by a zone controller and two pack controllers. Flight deck and cabin
temperature can be selected from the AIR panel in the cockpit.
A control panel is provided on the forward attendant panel. During cruise, the cabin crew can modify
each cabin zone temperature from the cockpit, with a limited authority of ± 3°C (5.4°F).
Low pressure air is supplied to the mixing unit via a ground connection.

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Contents A340-600 AIR CONDITIONING SEQ 100 REV 16
Flight Crew Operating Manual

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 15

MAIN COMPONENTS

AIR CONDITIONING PACK

The two packs operate automatically and independently of each other. Pack operation is controlled by
the pack controller.
Warm pre-conditioned bleed air enters the cooling path via the pack flow control valve and is ducted to
the primary heat exchanger.
Then, the cooled bleed air enters the compressor section of the aircycle machine and is compressed to
a higher pressure and temperature.
It is again cooled in the main heat exchanger, and enters the turbine section where it expands. In
expanding, it generates power to drive the compressor and cooling air fan.
The removal of energy during this process reduces the air temperature, resulting in a very low air
temperature at turbine discharge.
The temperature control valve can modify the pack outlet temperature by adding uncooled air to the
turbine outlet flow.
In case of an air cycle machine failure, bleed air is only cooled by the corresponding heat exchanger.

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Contents
A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 16

PACK SCHEMATIC

FOR INFO

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 17

PACK FLOW CONTROL VALVE

This valve is pneumatically-operated and electrically-controlled. It regulates the air flow in accordance
with signals received from the pack controller.
In the absence of air pressure, a spring keeps the valve closed.
In the absence of electrical supply, the valve pneumatically controls the flow to 125 %, provided air
supply is available.
The valve closes automatically in case of pack compressor overheating, engine starting, operation of the
fire or ditching pushbuttons, any unclosed doors at engine start, or insufficient upstream pressure. The
valve is controlled from the AIR panel.

RAM AIR
An emergency ram air inlet ventilates the cockpit and cabin, if both packs fail.
The emergency ram air inlet valve is controlled by the RAM AIR pushbutton on the AIR panel.
This pushbutton opens the ram air valve, provided that ditching is not selected.
The outflow valves open about 50 %, provided that they are under automatic control and UP is less than
one psi. They do not automatically open if they are under manual control, even if UP is less than one
psi. If UP is greater than one psi, the check valve, located downstream the ram air door, will not open.
No airflow will then be supplied.

MIXER UNIT
This unit mixes cold fresh air from the packs with the cabin air being recirculated through recirculation
fans. The mixer unit is also connected to the emergency ram air inlet and the low pressure ground inlets.
A pre-mixing chamber (duct mixer) enables the cargo temperature control with mixed air.
Note : In case both packs are inoperative, the recirculation valves are partially closed.

HOT AIR VALVES

These valves regulate the pressure of hot air, tapped upstream of the packs.
They are pneumatically-operated and electrically-controlled from the HOT AIR 1 and HOT AIR 2
pushbuttons on the AIR panel. In the absence of electrical supply, the hot air valves are closed. In the
absence of air pressure, a spring keeps the valve closed.
The valve closes automatically, if the duct overheats.

TRIM AIR VALVES

These valves are electrically-controlled by the zone controller. One trim air valve, associated with each
zone, adjusts the temperature by adding hot air from the two hot air manifolds. For the cockpit supply,
only one trim air valve is fitted to regulate air from the hot air manifold 2. Air from the hot air manifold 1
passes through a restrictor.

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 16

HOT AIR X VALVE

A HOT AIR X valve is fitted between the two hot air manifolds. The valve is normally closed. It
automatically opens, if one hot air supply fails.

TEMPERATURE AND FLOW REGULATION

Temperature regulation is automatic and controlled by one zone controller and two pack controllers.

PACK CONTROLLER
Each pack controller regulates the temperature of its associated pack, in accordance with a demand
signal from the zone controller, by modulating the temperature control valve and the ram air inlet flap.
The ram air inlet flap closes during takeoff and landing to avoid ingestion of foreign objects.
Note : During takeoff, the ram air inlet flap closes when the thrust lever is at or above CL, and the wheel
speed (sent by the BSCU) is at or above 70 knots.
During landing, they close as soon as the landing gear is compressed, and the speed is at or
above 70 knots.
They open, when the speed is below 70 knots, with a 15-second delay.
The pack controllers also provide flow regulation by modulating the associated pack flow control valve,
in accordance with the zone controller demand.

ZONE CONTROLLER
AIR FLOW CONTROL
Air flow is usually in the NORM position because air flow is automatically managed by the controller,
depending on the number of passengers entered in the MCDU. However, the other positions can be
selected to comply with warnings, cautions, or cabin needs.
Whatever the crew selects, the system receives a high flow demand for any of the following
circumstances :
– In single pack operation, or
– When the APU is supplying bleed air.

Note : Due to ambient conditions, high flow may not be achieved at APU supply.

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 103 REV 15

Engine pressure demand

When the cooling demand in one zone cannot be satisfied, if the bleed pressure is too low, the zone
controller sends a pressure demand signal to both engines' Engine Interface Units (EIU), in order to
increase the minimum idle and to raise the bleed pressure.
APU flow demand
When the APU bleed valve is open, the zone controller signals the APU Electronic Control Box ECB
to increase the APU flow output when any zone temperature demand cannot be satisfied.
Bleed temperature demand
If the cooling demand cannot be satisfied, the zone controller signals the Bleed Monitoring Computer
(BMC) to decrease the bleed temperature from normal (200°C) to reduced setting (150°C). This
reduction is inhibited, if the wing-anti-ice is ON.

TEMPERATURE REGULATION
The zone controller regulates the cabin and cockpit temperature.

BASIC TEMPERATURE REGULATION

The flight crew uses the temperature selectors on the air conditioning panel in the cockpit to select the
reference temperature. The flight attendant adjusts the cabin temperature from the Forward Attendant
Panel (FAP).
The cabin altitude can be automatically corrected to adjust the cabin temperature for passenger comfort.
The correction is done to the master temperature selected in the cockpit to compensate for the dryness
of the air and the coldness of the lining. (The altitude correction can be programmed, but the basic
manufacturer setting is without correction).
The zone controller computes a temperature demand, depending on the selected temperature and the
actual temperature.
The actual temperature is measured by sensors in the :
– Cockpit
– Lavatory extraction circuit and galley ventilation system for the cabin.
A signal corresponding to the lowest demanded zone temperature goes to the pack controller, which
then makes both packs produce the required outlet temperature.

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Flight Crew Operating Manual
SEQ 001 REV 17

OPTIMIZED TEMPERATURE REGULATION

The zone controller optimizes temperature by acting on the trim air valves.
The temperature selection range is from 18°C (64°F) to 30°C (86°F).

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 21

SYSTEM OPERATION UNDER FAILURE CONDITION

Each controller is composed of two identical channels. Only one channel is active. After each
touchdown, the active channel changes.

ZONE CONTROLLER
CHANNEL 1 OR 2 FAILURE
A channel 1 or 2 failure has no effect on zone temperature regulation.
CHANNELS 1 AND 2 FAILURE
Optimized and backup temperature regulation are lost. The packs deliver a fixed pack outlet temperature
of 20°C (68°F). A channel 1 and 2 failure removes all information from the ECAM COND page. Flow
selection from the AIR FLOW selector is lost.

PACK CONTROLLERS
CHANNEL 1 OR 2 FAILURE
A channel 1 or 2 failure has no effect on pack regulation.
CHANNELS 1 AND 2 FAILURE
The pack outlet temperature is controlled at 12° C ± 6° C (54° F ± 11° F) by the corresponding anti-ice
valve. The ECAM signals, associated with the corresponding pack, are lost. The flow control valve
pneumatically regulates pack flow to approximately 125% of the NORM flow.

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 21

AIR CYCLE MACHINE FAILURE

If the Air Cycle Machine (ACM) fails (compressor/turbine seizure), the affected pack may be operated in
the heat exchanger cooling mode. Warm pre-conditioned bleed air enters the cooling path via the pack
flow control valve and goes to the primary heat exchanger. Then, the compressor check valve opens
and air is cooled only by the heat exchanger. The ACM seizure reduces the pack flow.
As they do for normal pack operation :
– The pack controller regulates temperature, in accordance with zone controller demand, by modulating
the temperature control valve and the ram air inlet flap.
– The zone controller regulates the hot air flow through the trim air valves to optimize cockpit/cabin
temperature regulation. Hot air flow is lower than for normal pack operation, because pack flow is
reduced.
Note : A pack with a seized ACM must be switched off on ground due to unavailability of RAM air
cooling.

HOT AIR VALVES FAILURE

One or both valves failed open : No effect.
One valve failed closed : No effect (HOT AIR X valve opens).
Both valves failed closed : Optimized regulation is lost. Trim air valves are driven to full
closed position. Pack outlet temperture is regulated according
to the lowest cabin demand.

TRIM AIR VALVE FAILURE

Failed closed : Optimized temperature regulation is lost in the affected zone.
Failed open : The higher heat load of the affected cabin zone will be
compensated by a decreasing pack outlet temperature.

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 105 REV 17

CONTROLS AND INDICATORS

OVERHEAD PANEL

PACK pushbutton
On : The pack flow control valve is automatically-controlled.
It opens, except in the following cases :
– Upstream pressure below minimum,
– Compressor outlet overheat,
– Engine start sequence :
1. Both valves close when :
• The MODE selector is set to IGN, when on ground (valves reopen if
MASTER switch or MAN START pushbutton are not set to ON within
30 seconds)
• The MODE selector is set to IGN (or CRANK) and when (on either
engine):
– The MASTER switch is set to ON (or MAN START pushbutton is
set to ON) and,
– The start valve is open, and
– N3 < 50 %.
2. On ground, reopening of the valves is delayed 30 seconds to avoid a
supplementary pack closure cycle during subsequent engine start.
– Any door is not closed and locked, aircraft on ground, and any engine
running.
– Onside engine fire pushbutton is pressed.
– Ditching is selected.
Note : If there is no electrical power, the flow valves remain open and
permit 125 % flow.
OFF : The pack flow control valve closes, provided it is electrically-supplied.
FAULT lt : The amber light and associated ECAM caution come on, when the pack flow
control valve position disagrees with the selected position, or in case of
compressor outlet overheat or pack outlet overheat.

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Flight Crew Operating Manual
SEQ 105 REV 20

AIR FLOW selector

The airflow selector has four positions : LO, NORM, HI, and MAN.
LO represents 80% of NORM flow, when there is no cargo cooling ; HI is the equivalent of NORM +
200 pack airflow liters/sec. LO, NORM and HI operate with automatic air management. MAN,
operates without air management.
Air management keeps the total airflow (pack + cabin recirculated) constant, and computes both the
pack airflow quantity and cabin recirculated airflow quantity, depending on the airflow selector
position, the number of passengers and seats, and the cargo cooling selection. If one bleed fails,
maximum flow is limited to 108%. In single pack operations, or with APU bleed supply, any selection
is irrelevant since, in such cases, a high flow is automatically regulated.

Zone temperature selector

– 12 o'clock position : 24° C (76° F)
– COLD position : 18° C (64° F)
– HOT position : 30° C (86° F)

HOT AIR 1 (or 2) pushbutton

On : The valve regulates hot air pressure.
OFF : The valve closes.
The FAULT circuit is reset.
Forward cargo heating is lost, if HOT AIR 1 is affected .
Aft cargo heating is lost, if HOT AIR 2 is affected .
FAULT lt : The amber light, and associated ECAM caution, come on when duct
overheat is detected (88° C/190°F). The valve, and the associated trim air
valves automatically close. The FAULT light goes off, when temperature
drops below 70° C, and the flight crew selects OFF.

RAM AIR pushbutton (guarded)

ON : The ON light comes on white.
If the DITCHING pushbutton, on the CABIN PRESS panel, is in the normal
position :
– The RAM air inlet opens.
– If Up < 1 psi : Each outflow valve opens to about 50 %, when under
automatic control. They do not automatically open when under manual
control. The emergency ram air flow is directly supplied to the mixer unit.
– If UP ≥ 1 psi : Each outflow valve remains normally controlled. No
emergency ram air flows in.
Off : The RAM air inlet closes and the outflow valves return to normal position.

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 100 REV 16

CAB FANS pb
On : The three cabin fans run. Two of them blow air from the cabin to the avionics
compartment and to the conditioning system's mixing unit. The third one only
blows air to the conditioning system's mixing unit.
OFF : The three cabin fans stop.
Note : If a fan failure occurs, the ECAM caution is displayed.

FORWARD ATTENDANT PANEL

Allows fine trimming of individual zone temperature (± 3°C/± 5.4°F).

ADDITIONAL ATTENDANT PANEL

The additional attendant panels can be installed in different locations.
The temperature setting of the related zone can be changed (± 3°C/± 5.4°F).

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Flight Crew Operating Manual
SEQ 100 REV 22

ECAM BLEED PAGE

Pack flow control valve

Crossline - Amber : Valve is closed.
In line - Amber : Valve is failed open.
In line - Green : Valve is not fully closed.

Pack flow indication

The needle position (green) represents the actual flow rate.
LO : 80 % airflow
HI : NORM airflow + 200 liters per second.

Target airflow
The small circle represents the target airflow. The circle is always in cyan.
If the target airflow data is unavailable (at pneumatic flow regulation or at APU
supply), the circle is removed.

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Flight Crew Operating Manual
SEQ 105 REV 22

Pack outlet temperature indication

It normally appears in green.
But it is appears in amber, if the temperature is higher than 95°C. It remains amber as
long as the temperature is not lower than 60°C.

Emergency Ram Air inlet indication

Crossline - Green : The flap is normally closed.
In transit - Amber : The flap is partially open.
In line - Amber : If open on ground, or if the flap position disagree with the
positionof theRAM AIR pushbutton (OFF).
In line - Green : The flap is fully open.
Crossline - Amber : The flap is closed, and the RAM AIR pushbutton is in the ON
position.

By pass valve indication

Triangle - Green : The bypass valve is normally open.
Triangle - Amber : The bypass valve is failed open.
No Display : The bypass valve is fully closed

Bleed users' indication

It normally appears in green.
But, it appears in amber, when the RAM AIR flap is fully closed, if no air comes from the
two packs, or if the flow control valves are fully closed.

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Flight Crew Operating Manual
SEQ 100 REV 16

ECAM COND PAGE

System page title

Unit of displayed temperatures

Indication of the cabin recirculation fans status

If no fan is failed, nothing is displayed.
CAB FAN : Amber if 3 fans are failed.
123 : Fan failed in amber, the others in green.

Zone controller indication

ZONE CTRL : It is not displayed, if both systems are operative.
It is amber, if both systems are faulty.
It is green, if only one system is faulty.
1 (2) : It is an amber number, with a grey frame, if System 1(2) is faulty.
It is a green number, with grey frame, if System 1(2) is not faulty, and System
2(1) is faulty.
It is not displayed, if both systems are operative.

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Flight Crew Operating Manual
SEQ 100 REV 16

Ventilation controller indication

VENT CTRL : It is not displayed, if both systems are operative.
It is amber, if both systems are faulty.
It is green, if only one system is faulty.
1 (2) : It is an amber number, with a grey frame, if System 1(2) is faulty.
It is a green number, with a grey frame, if System 1(2) is not faulty, and
System 2(1) is faulty.
It is not displayed, if both systems are operative.

Zone temperature
The indication is in green.
Note : This information is also displayed on the ECAM CRUISE page.

Zone duct temperature

Normally, the indication is in green. It becomes amber, in case of a duct overheat.

Hot air shutoff valve position

Crossline - Green : Valve is normally closed.
In line - Green : Valve is normally open.
Crossline - Amber : Valve is abnormally closed.

Hot air pressure regulating valve position 1 (2)

In line - Green : Valve is normally open, and the Flow Control Valve 1(2)open.
In line - Amber : Valve is abnormally open.
Crossline - Green : Valve is normally closed.
Crossline - Amber : - Valve is abnormally closed, or
- Flow Control Valve 1(2) is closed, or
- The respective HOT AIR pb is OFF, or
- There is a duct overheat for the related Trim Air Valve.

Pack 1 (2) Indication

Triangle 1(2) is in green, and text PACK 1(2) is in white, when the flow control valve 1(2) is not fully
closed.
Triangle 1(2) is in amber, and text PACK 1(2) is in amber, when the flow control valve 1(2) is fully
closed.

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Flight Crew Operating Manual
SEQ 001 REV 07

ECAM CAB PRESS PAGE

PACK indication
pack flow control valve open :
U Green
PACK 1 White
pack flow control valve closed :
U Amber
PACK 1 Amber

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Flight Crew Operating Manual
SEQ 105 REV 15

ECAM CRUISE PAGE

Cockpit and cabin zones air temperature

Only the cockpit and four cabin temperature zones are displayed (each one corresponding to the
mean value of zone 1-2, 3-4, 5-6 and 7-8).

Forward cargo temperature

Aft cargo temperature

Bulk cargo temperature

Note : The forward, Aft and Bulk cargo indication do not appear when the corresponding temperature
control option is not installed.

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A340-600 AIR CONDITIONING
Flight Crew Operating Manual
SEQ 200 REV 19

WARNINGS AND CAUTIONS

SD FLT
E/WD : FAILURE TITLE AURAL MASTER LOCAL
PAGE PHASE
conditions WARNING LIGHT WARNING
CALLED INHIB
PACK 1(2) OVHT
Pack compressor outlet temperature > 260°C,
PACK 3, 4, 5,
or pack outlet temp > 95°C.
FAULT lt 7, 8
PACKVALVE1(2) FAULT
SINGLE MASTER
Pack valve disagrees with selected position.
CHIME CAUT
PACK1(2) OFF PACK 1 to 5
Pack pb at off, with no failure. BLEED OFF lt 7 to 10
PACK 1+2 FAULT PACK
One pack off, then the other fault. FAULT lt
PACK 1(2) REGUL FAULT 3, 4, 5,
Pack controller failed, or air is only cooled by heat exchanger 7, 8
(ACM fault, or RAM door failed closed, or Temperature Control
Valve failed). NIL NIL
ZONE CTL SYS 1(2) FAULT NIL 1, 2, 3,
One zone controller channel is failed. COND 4, 5, 7,
8
ZONE REGUL FAULT
Zone controller failed, or hot air valve 1+2 failed. SINGLE MASTER
DUCT OVHT CHIME CAUT HOT AIR 3, 4, 5,
COND
Duct temp > 88°C FAULT lt 7, 8
HOT AIR SYS 1(2) FAULT
Hot air valve 1(2) and hot air x valve failed closed.
PACK 1(2) SYS 1(2) FAULT NIL NIL NIL
Total loss of pack controller 1(2) detected of the pack controller NIL 3 to 8
lane 1(2).
* Only in case of a single failure.

MEMO DISPLAY
– The RAM AIR message appears in green, if the RAM AIR pushbutton is ON.
It becomes amber in flight Phases 1 and 2.

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