B767 Air Systems
DO NOT USE FOR FLIGHT
Boeing B767 - Systems Summary [Air Systems]
2.20 Air Systems-Air Conditioning System Description
Introduction to Air Conditioning System
The air conditioning system supplies conditioned bleed air and recirculated cabin
air at a controlled temperature throughout the airplane.
The system supplies conditioned air to the flight deck shoulder heaters.
The system supplies ventilation for the cabin:
• lavatories
• galleys.
Pack control, zone temperature control, cabin air recirculation, fault detection, and
overheat protection are all automatic.
The airplane is divided into four temperature zones: the flight deck and three cabin
zones.
Air Conditioning Packs
Two identical air conditioning packs cool bleed air from the engines, APU, or high
pressure air from a ground source. Bleed air is precooled before entering the pack.
The packs are controlled by two identical pack controllers. Pack output is
automatically increased during high pack demand periods (to compensate for a
failed pack or recirculation fan), or limited during high bleed air demand periods
(such as with an engine inoperative).
Air Conditioning Automatic Mode
With the pack selector in the AUTO position, pack output temperature is
determined by the left and right cabin temperature controllers:
Air Conditioning Standby Mode
With the pack selector in the standby mode, pack output temperature is determined
by the position of the pack selector:
• N (normal) - constant, moderate temperature
• C (cool) - full cold
• W (warm) - full warm.
Ground Conditioned Air Operation
When a ground source of conditioned air is available, it may be used to supply
conditioned air directly to the cabin distribution system, eliminating the need for
pack operation.
Page 2
Boeing B767 - Systems Summary [Air Systems]
Pack Non–Normal Operation
Pack control, fault detection, and overheat protection are all automatic.
The pack INOP light illuminates and the EICAS advisory message L or R PACK
TEMP displays for all pack control system faults and overheats.
When an automatic control system fault or a pack outlet overheat is detected, the
pack continues to operate in an uncontrolled, degraded condition, requiring crew
interaction.
The pack valve closes and the pack is shut down automatically when an internal
pack overheat is detected. The PACK OFF light illuminates and the EICAS
advisory message L or R PACK OFF displays in addition to the PACK TEMP
indications.
If the INOP light remains illuminated after selecting STBY, the fault is a pack
overheat. After the pack has cooled, an attempt to restore pack operation may be
made by pushing the PACK RESET switch.
Air Distribution
Conditioned air from the packs flows into a mix manifold where it mixes with air
from two recirculation fans. Recirculation fans maintain overall cabin air
circulation while allowing a reduction of cabin air ventilation, permitting the
packs to be operated at a reduced flow. The mixed air is then ducted into the cabin.
The recirculation fans may be turned off for several minutes to provide a more
rapid exchange of air.
The recirculation fan INOP light illuminates and the EICAS advisory message L
or R RECIR FAN displays whenever a recirculation fan fails or is not operating.
A slight increase in fuel consumption occurs for each fan that is OFF.
Temperature Control
The airplane is divided into four temperature control zones:
• flight deck
• forward cabin
• mid cabin
• aft cabin.
The pack controllers regulate the pack output air temperature to satisfy the
temperature requirement of the compartment requiring the coolest air. Hot trim air
from the bleed air system is added through trim air valves to control the
temperature in each of the other compartments. Each temperature control
compartment has an associated temperature control.
Page 3
Boeing B767 - Systems Summary [Air Systems]
A compartment INOP light illuminates, and the EICAS advisory message FLT
DECK TEMP, FWD CABIN TEMP, MID CABIN TEMP, or AFT CABIN TEMP
displays to indicate:
• zone temperature controller failure
• trim air switch is OFF
• compartment temperature control is in the OFF position (FWD, MID, and
AFT CAB only).
Temperature Control With Loss of Trim Air System
During operation with the trim air system off, the packs attempt to maintain all
compartments at an average temperature. The trim air OFF light illuminates and
the EICAS advisory message TRIM AIR displays when a TRIM AIR switch is off.
Gasper System
[Gasper System description included when the Gasper Fan Switch option is
installed.]
The gasper system draws air from the forward cabin overhead air conditioning
ducts and discharges it from gasper outlets in the passenger service units located
above each passenger seat. Gasper air is controlled by the GASPER fan switch.
Page 4
Boeing B767 - Systems Summary [Air Systems]
Air Conditioning System Schematic
COMPT TEMP
1
FLT DK
INOP
C
W
AUTO
C
MAN
W
INOP
INOP
INOP
FWD CAB
AUTO
MID CAB
AUTO
AFT CAB
AUTO
C
OFF
W
C
OFF
L
TRIM AIR
C
W
OFF
RECIRC FAN
W
R
ON
ON
ON
OFF
INOP
INOP
1
FLT DK
INOP
C
AUTO
L PACK
RESET
INOP
C
PACK
OFF
1
FLT DK TEMPERATURE
CONTROL INDICATORS
TRANSPOSED FROM PANEL
POSITION TO IMPROVE
FUNCTIONAL DESCRIPTION.
OFF
N
W
SUPPLY AIR
EXHAUST AIR
AUTO
PNEUMATIC
SUPPLY
W
R PACK
RESET
S
CT
B
Y
MAN
W
OFF
INOP
PACK
OFF
AUTO
N
W
S
CT
B
Y
PNEUMATIC
SUPPLY
Shoulder and Foot Heaters
Flight crew shoulder and foot heat is provided by electric heaters in the ducts that
supply conditioned air to the side windows and rudder pedal areas respectively.
The heaters operate in flight only.
Page 5
Boeing B767 - Systems Summary [Air Systems]
Equipment Cooling System
Forward Equipment Cooling
The forward equipment cooling system supplies cooling air to equipment in the
forward electronic equipment racks and the flight deck avionics.
System operation is automatic with the EQUIP COOLING selector in AUTO.
On the ground, engine operation, pack operation, air/ground logic, airplane skin
temperature and ambient temperature are all factors that determine system
configuration. A supply fan and an exhaust fan either recirculate the cooling air
back through the system, or port it overboard.
In flight, only the exhaust fan operates, and the air is recirculated through the
system.
Non-Normal Operation
The VALVE light illuminates and the EICAS advisory message FWD EQPT VAL
displays if the system valves fail to reconfigure during automatic operation.
Placing the EQUIP COOLING selector in STBY provides an alternate command
to reconfigure the system for recirculating the cooling air back through the
system,.
The OVHT light illuminates and the EICAS advisory message FWD EQPT
OVHT displays if low airflow or high temperature is sensed. Placing the EQUIP
COOLING selector in STBY may correct the condition by reconfiguring the
system.
The SMOKE light illuminates and the EICAS advisory message FWD EQPT
SMOKE displays if smoke is sensed in the forward equipment cooling ducts.
Placing the EQUIP COOLING selector in OVRD allows conditioned air to be
drawn in reverse through the system by differential pressure and exhausted
overboard.
The NO COOLING light illuminates and the EICAS caution message FWD EQPT
COOLING displays if no cooling airflow is sensed after selecting OVRD.
Cargo Heat System
The forward and aft cargo compartments are provided heat from the bleed air
system.
The forward, aft, and bulk cargo compartments are provided heat from the bleed
air system.
Page 6
Boeing B767 - Systems Summary [Air Systems]
Normal Operation
Separate switches control a shutoff valve and a heat control valve in each
compartment. The system automatically maintains compartment temperature
above approximately 45°F (7°C).
Bulk Cargo Heat Selector
[When the Bulk Cargo Heat option is installed, the Bulk Cargo Heat Panel
will contain either the NORM/VENT selector switch or the
CARGO/ANIMAL selector switch.]
A BULK CARGO HEAT selector allows a higher temperature to be selected for
the bulk compartment. With the selector in the NORM position, the bulk
compartment operates the same as the forward and aft compartments. With the
selector in the VENT position, the bulk compartment is maintained above
approximately 65°F (18°C), and a vent fan draws cabin discharge air into the
compartment.
A BULK CARGO HEAT selector allows a higher temperature to be selected for
the bulk compartment. With the selector in the CARGO position, the bulk
compartment operates the same as the forward and aft compartments. With the
selector in the ANIMAL position, the bulk compartment is maintained above
approximately 65°F (18°C), and a vent fan draws cabin discharge air into the
compartment.
Non-Normal Operation
[This paragraph applies to aircraft without the Bulk Cargo Heat option.]
The cargo heat switch OVHT light illuminates, and the EICAS advisory message
FWD or AFT CARGO OVHT displays when the cargo compartment temperature
is above the standard control range. The compartment shutoff valve closes
automatically if a compartment temperature exceeds approximately 90°F (32°C).
When the compartment temperature decreases below the overheat temperature
setting, the OVHT light extinguishes, the EICAS message is removed, and the
compartment shutoff valve re–opens.
[This paragraph applies to aircraft with the Bulk Cargo Heat option.]
The cargo heat switch OVHT light illuminates and the EICAS advisory message
FWD, AFT or BULK CARGO OVHT displays when the cargo compartment
temperature is above the standard control range. The compartment shutoff valve
closes automatically if a compartment temperature exceeds approximately 90°F
(32°C). When the compartment temperature decreases below the overheat
temperature setting, the OVHT light extinguishes, the EICAS message is
removed, and the compartment shutoff valve re–opens.
Page 7
Boeing B767 - Systems Summary [Air Systems]
2.30 Air Systems-Pressurization System Description
Introduction to Pressurization System
Cabin pressurization is controlled by adjusting the discharge of conditioned cabin
air through the outflow valve.
Positive pressure relief valves and negative pressure relief doors protect the
fuselage against excessive pressure differential.
The pressurization system has automatic and manual operating modes.
Pressurization System Automatic Operation
The pressurization system is in the automatic mode when the cabin altitude mode
selector is set to AUTO 1 or AUTO 2. If the selected auto mode fails, control is
automatically switched to the other auto mode.
In the automatic mode, the pressurization system uses ambient pressure data from
the air data system in conjunction with the selected cabin auto rate, the takeoff
altitude and the indicated landing altitude to calculate the cabin pressurization
schedule.
Takeoff
For takeoff, the system supplies a small positive pressurization to cause a smooth
cabin altitude transition.
Climb
During climb, cabin altitude increases on a schedule related to the takeoff field
elevation, airplane altitude, and the selected auto climb rate limit.
If the maximum cabin pressure differential is reached, cabin climb rate becomes
a function of airplane climb rate, while maintaining the maximum differential
pressure.
Cruise
Shortly after the airplane levels off, the system enters the cruise mode. The landing
altitude and the scheduled cabin altitude are compared and the higher of these two
is selected for the cruise cabin altitude. If necessary, the cabin climbs to the cruise
cabin altitude at one–half the auto rate or descends to the cruise cabin altitude at
the auto rate.
The cruise cabin altitude does not change for minor altitude variations. A
significant altitude change causes the system to re–enter the climb mode or to
enter the descent mode.
Page 8
Boeing B767 - Systems Summary [Air Systems]
Descent and Landing
During descent, cabin altitude decreases to slightly below the selected landing
altitude. This ensures that the airplane lands pressurized. Landing altitude
barometric pressure correction comes from the captain’s altimeter.
At touchdown, the outflow valve opens to depressurize the airplane.
Non–Normal Indications
If the cabin altitude climbs above 10,000 feet, the CABIN ALT and CABIN
ALTITUDE lights illuminate and the EICAS warning message CABIN
ALTITUDE displays. The lights extinguish and the EICAS message blanks when
the cabin altitude descends below 8,500 feet.
The AUTO INOP light illuminates and the EICAS caution message CABIN
AUTO INOP displays when automatic pressurization control fails or when cabin
altitude MODE SELECT is MAN. Manual operation is required if the automatic
system fails.
Only the automatic mode is equipped with an aneroid switch that automatically
closes the outflow valve when the cabin exceeds 11,000 feet. The manual mode
has no auto closure feature.
To operate the pressurization system manually:
• set the cabin altitude MODE SELECT to MAN
• hold the cabin altitude MANUAL control to CLIMB to move the outflow
valve toward open and cause the cabin altitude to climb
• hold the cabin altitude MANUAL control to DESCEND to move the
outflow valve toward closed and cause the cabin altitude to descend.
Page 9
Boeing B767 - Systems Summary [Air Systems]
2.40 Air Systems-Bleed Air System Description
Introduction to Bleed Air System
Bleed air can be supplied by the engines, APU, or a ground air source.
Bleed air is used for:
• air conditioning
• pressurization
• engine start
• wing and engine anti–ice
• center hydraulic system air driven pump (ADP)
• hydraulic reservoir pressurization
• thrust reversers
Engine Bleed Air Supply
Engine bleed air comes from either the high pressure (HP) or the low pressure
(LP) engine compressor sections. LP air is used during high power setting
operations. HP air is used during descent and other low power setting operations.
The engine bleed air valves are armed when the engine bleed switches are selected
ON. The valves are pressure actuated and remain closed until engine bleed air
pressure is sufficient to cause forward flow. The valves may close when the APU
is starting either engine. The valves may close when ground pneumatic air is
connected or during periods of low engine bleed air demand, such as when the air
conditioning packs are off.
The engine bleed air OFF light illuminates and the EICAS advisory message L or
R ENG BLEED OFF displays when the engine bleed air valve is closed for a
system fault.
The OVHT light illuminates and the EICAS advisory message L or R ENG BLD
OVHT displays when the engine bleed air temperature is excessive.
The BLEED light illuminates and the EICAS advisory message L or R ENG
HPSOV displays when the engine high pressure bleed air valve is open when
commanded closed.
The BLEED light illuminates and the EICAS advisory message L or R ENG PRV
displays when the pressure regulating valve is open when commanded closed.
Page 10
Boeing B767 - Systems Summary [Air Systems]
APU Bleed Air Supply
APU bleed air is used primarily during ground operations for air conditioning
pack operation and engine starting. In flight, APU bleed air is available up to
approximately 17,000 feet.
The check valve in the APU supply line prevents reverse flow of bleed air from
the duct into the APU.
The VALVE light illuminates and the EICAS advisory message APU BLEED
VAL displays when the APU bleed valve position disagrees with the commanded
position.
Ground Pneumatic Air Supply
External connectors are provided to connect a ground source of high pressure air
directly to the bleed air duct.
Check valves prevent reverse flow of bleed air from the bleed air duct to the
connectors.
Bleed Air Duct System
The duct pressure indicator displays the pressure in the left and right bleed air
ducts.
Isolation valves separate the bleed air ducts into isolated segments. The left and
right isolation valves are normally closed except for engine start or single bleed
source operation. The center isolation valve normally remains open.
The isolation VALVE lights illuminate and the EICAS advisory message C, L or
R BLD ISLN VAL displays when the bleed isolation valve position disagrees with
the commanded position.
The DUCT LEAK light illuminates and the EICAS caution message L or R BLD
DUCT LEAK, BODY DUCT LEAK or STRUT DCT LEAK displays when a
high temperature bleed air leak is detected.
Page 11
Boeing B767 - Systems Summary [Air Systems]
Bleed Air System Schematic
L PACK
GROUND
PNEUMATIC
R PACK
60
80
20
0
DUCT
PRESS
PSI
40
L ISLN
FWD CARGO
HEAT
R ISLN
VALVE
VALVE
C ISLN
L WING
ANTI-ICE
R WING
ANTI-ICE
V
A
L
V
E
DUCT
LEAK
DUCT
LEAK
BLEED
BLEED
D
U
C
T
OVHT
L
HYD
RES
L
E
A
K
AFT
CARGO
HEAT
C
HYD
RES
R
HYD
RES
BULK
CARGO
HEAT
L ENG
APU
V
A
L
V
E
O
F
F
OVHT
ADP
R ENG
O
F
F
R THRUST REV
L THRUST REV
APU
ENGINE
ANTI-ICE
PRV
PRV
STARTER
ENGINE
ANTI-ICE
LP
LP
HPSOV
HPSOV
PANEL FLOW LINES
FLOW LINES NOT ON PANEL
Page 12
STARTER
Boeing B767 - Systems Summary [Air Systems]
L PACK
R PACK
60
GROUND
PNEUMATIC
80
DUCT
PRESS
PSI
40
20
L ISLN
FWD CARGO
HEAT
0
R ISLN
VALVE
VALVE
C ISLN
L WING
ANTI-ICE
R WING
ANTI-ICE
V
A
L
V
E
DUCT
LEAK
DUCT
LEAK
BLEED
BLEED
D
U
C
T
OVHT
L
HYD
RES
L
E
A
K
AFT
CARGO
HEAT
C
HYD
RES
APU
V
A
L
V
E
ENGINE
ANTI-ICE
PRV
PRV
STARTER
R ENG
O
F
F
APU
ENGINE
ANTI-ICE
R
HYD
RES
BULK
CARGO
HEAT
L ENG
O
F
F
OVHT
ADP
LP
LP
HPSOV
HPSOV
PANEL FLOW LINES
FLOW LINES NOT ON PANEL
Page 13
STARTER
Boeing B767 - Systems Summary [Air Systems]
2.50 Air Systems-Air Systems EICAS Messages
Air Systems EICAS Messages
The following EICAS messages can be displayed.
Message
Level
Light
Aural
Condition
APU BLEED VAL
Advisory
VALVE
L BLD DUCT LEAK
Caution
DUCT
LEAK
Advisory
VALVE
Bleed isolation valve
position disagrees with
the commanded position.
CABIN ALTITUDE
Warning
CABIN
Siren
ALTITUDE,
CABIN
ALT
Cabin altitude excessive.
CABIN AUTO INOP
Caution
AUTO
INOP
Automatic pressurization
control has failed or the
cabin altitude mode
selector is in manual.
AFT CABIN TEMP
Advisory
INOP
R BLD DUCT LEAK
APU bleed valve position
disagrees with the
commanded position.
Beeper
A high temperature bleed
air leak is detected.
BODY DUCT LEAK
C BLD ISLN VAL
L BLD ISLN VAL
R BLD ISLN VAL
FWD CABIN TEMP
MID CABIN TEMP
Beeper
A fault in the zone
temperature controller,
compartment temperature
control is in the OFF
position, or trim air
switch OFF.
[This EICAS message applies to aircraft with the Bulk Cargo Heat option.]
AFT CARGO OVHT
Advisory
OVHT
BULK CARGO
OVHT
FWD CARGO OVHT
Page 14
Cargo compartment
temperature above
standard control range.
Boeing B767 - Systems Summary [Air Systems]
Message
Level
Light
Aural
Condition
[This EICAS message applies to aircraft without the Bulk Cargo Heat option.]
AFT CARGO OVHT
Advisory
OVHT
Cargo compartment
temperature above
standard control range.
L ENG BLEED OFF
R ENG BLEED OFF
Advisory
OFF
Engine bleed air valve is
closed for a system fault.
L ENG BLD OVHT
Advisory
OVHT
Engine bleed air
temperature is excessive.
Advisory
BLEED
High pressure bleed air
valve is open when
commanded closed.
Advisory
BLEED
Pressure regulating valve
is open when
commanded closed.
FWD EQPT
COOLING
Caution
NO
COOLING
Beeper
FWD EQPT OVHT
Advisory
OVHT
Ground High temperature or low
airflow in equipment
crew
cooling system.
call
horn on
ground
FWD EQPT SMOKE
Advisory
SMOKE
Smoke detected in the
forward equipment
cooling ducts.
FWD EQPT VAL
Advisory
VALVE
An equipment cooling
valve not in commanded
position.
FLT DECK TEMP
Advisory
INOP
A fault in the zone
temperature controller or
trim air switch OFF.
L PACK OFF
Advisory
PACK OFF
Pack valve is closed.
Advisory
INOP
Automatic control system
fault or overheat.
FWD CARGO OVHT
R ENG BLD OVHT
L ENG HPSOV
R ENG HPSOV
L ENG PRV
R ENG PRV
OVRD selected and no
reverse airflow detected
through the E/E
compartment avionics.
R PACK OFF
L PACK TEMP
R PACK TEMP
Page 15
Boeing B767 - Systems Summary [Air Systems]
Message
L RECIR FAN
Level
Light
Advisory
INOP
Caution
DUCT
LEAK
Advisory
OFF
Aural
Fan is failed or not
operating.
R RECIR FAN
L STRUT DCT
LEAK
Condition
Beeper
A high temperature bleed
air leak is detected.
R STRUT DCT
LEAK
TRIM AIR
Page 16
Trim air switch OFF.
Boeing B767 - Systems Summary [Air Systems]
2.10 Air Systems-Controls and Indicators
Air Conditioning System
Air Conditioning Control Panel
[Air Conditioning Control Panel shown without the Gasper Fan Switch option.]
COMPT TEMP
1
2
INOP
INOP
INOP
FWD CAB
AUTO
MID CAB
AUTO
AFT CAB
AUTO
3
C
OFF
C
W
TRIM AIR
4
5
OFF
C
W
W
OFF
L - RECIRC FAN - R
ON
ON
ON
10
OFF
INOP
INOP
11
FLT DK
6
INOP
C
AUTO
7
8
9
R PACK
RESET
L PACK
RESET
INOP
C
PACK
OFF
OFF
AUTO
W
N
W
MAN
S
T
C
B
Y
W
OFF
13
INOP
PACK
OFF
AUTO
OVERHEAD PANEL
Page 17
12
N
W
S
CT
B
Y
14
Boeing B767 - Systems Summary [Air Systems]
[Air Conditioning Control Panel shown with the Gasper Fan Switch option.]
COMPT TEMP
1
2
INOP
INOP
INOP
FWD CAB
AUTO
MID CAB
AUTO
AFT CAB
AUTO
3
C
OFF
C
W
TRIM AIR
4
OFF
C
W
W
OFF
L - RECIRC FAN - R
ON
ON
ON
10
5
OFF
INOP
INOP
11
6
GASPER
FLT DK
15
ON
INOP
16
OFF
AUTO
7
8
9
C
R PACK
RESET
L PACK
RESET
INOP
C
PACK
OFF
OFF
AUTO
W
N
W
MAN
S
T
C
B
Y
PACK
OFF
AUTO
N
W
S
CT
B
Y
OVERHEAD PANEL
1
Compartment Temperature (COMPT TEMP) Indicators
Displays actual temperature sensed in the compartment.
2
Compartment Temperature Inoperative (INOP) Lights
Illuminated (amber) –
• fault in the zone temperature controller
• the Compartment Temperature Control is OFF
• the trim air switch is OFF.
Page 18
13
INOP
W
OFF
12
14
Boeing B767 - Systems Summary [Air Systems]
3
Compartment Temperature Controls
AUTO –
• provides automatic compartment temperature control
• rotating the control toward C (cool) or W (warm) sets the desired
temperature between 18 degrees C and 30 degrees C.
OFF –
• closes the compartment trim air valve
• the compartment temperature INOP light illuminates.
4
TRIM AIR Switch
ON – the trim air valve is commanded open.
Off (ON not visible) – the trim air valve is commanded closed.
5
Trim Air OFF Light
Illuminated (amber) – the TRIM AIR switch is off.
6
Flight Deck (FLT DK) Temperature Inoperative (INOP) Light
Illuminated (amber) –
• fault in the zone temperature controller.
• the trim air switch is OFF.
7
PACK RESET Switches
Push – resets an overheated pack if the pack has cooled to a temperature below the
overheat level.
8
Pack Inoperative (INOP) Light
Illuminated (amber) –
• the pack is overheated
• fault in the automatic control system.
9
PACK OFF Lights
Illuminated (amber) – pack valve is closed.
10
Recirculation Fan (RECIRC FAN) Switches
ON – the recirculation fan operates
Off (ON not visible) – the recirculation fan does not operate.
Page 19
Boeing B767 - Systems Summary [Air Systems]
11
Recirculation Fan Inoperative (INOP) Lights
Illuminated (amber) –
• the recirculation fan is failed or is not operating.
• the RECIRC FAN switch is off.
12
Flight Deck Trim Air Valve Position Indicator
C (cool) – valve closed.
W (warm) – valve open.
13
Flight Deck Compartment Temperature Control
AUTO –
• provides automatic flight deck temperature control
• rotating the control toward C (cool) or W (warm) sets the desired
temperature between 18 degrees C and 30 degrees C.
MAN –
• provides manual control of compartment trim air valve
• spring loaded to the 6 o’clock position in this sector.
14
PACK Control Selectors
OFF – closes the pack valve.
AUTO – the pack is automatically controlled.
STBY –
• N (normal) – regulates the pack outlet temperature to a constant, moderate
temperature.
• C (cool) – sets the pack to full cold operation.
• W (warm) – sets the pack to full warm operation.
15
GASPER Fan Switch
[Gasper Fan Switch and OFF light description provided when the Gasper
Fan Switch option is installed.]
ON – the gasper fan is signaled on.
Off (ON not visible) – the gasper fan is signaled off.
16
Gasper Fan OFF light
Illuminated (amber) – the GASPER fan switch is ON but the gasper fan is not
operating.
Page 20
Boeing B767 - Systems Summary [Air Systems]
Shoulder and Foot Heaters
HEATERS
FOOT
1
HI
LOW
OFF
SHOULDER
2
LEFT AND RIGHT SIDEWALL
1
FOOT HEATERS Switch
HIGH – the electric heater adds heat at high setting to the conditioned air flowing
to the rudder pedal area in flight only.
LOW – the electric heater adds heat at low setting to the conditioned air flowing
to the rudder pedal area in flight only.
OFF – the electric heater is not operating (no heat added to the conditioned air
flowing to the rudder pedal area).
2
SHOULDER HEATERS Switch
HIGH – the electric heater adds heat at high setting to the conditioned air flowing
to the side window area in flight only.
LOW – the electric heater adds heat at low setting to the conditioned air flowing
to the side window area in flight only.
OFF – the electric heater is not operating (no heat added to the conditioned air
flowing to the side window area).
Equipment Cooling Panel
CABIN
ALTITUDE
1
2
PRESS DIFF
LIMIT: T/O &
LDG.125 PSI
EQUIP COOLING
AUTO
STBY
OVRD
NO
COOLING
OVERHEAD PANEL
Page 21
VALVE
3
OVHT
4
SMOKE
5
Boeing B767 - Systems Summary [Air Systems]
1
Equipment (EQUIP) COOLING Selector
AUTO – automatically controls equipment cooling system.
STBY – positions equipment cooling system for inboard air flow.
OVRD – positions equipment cooling system for reverse air flow.
2
NO COOLING Light
Illuminated (amber) –
• active in OVRD only
• no reverse air flow through the E/E compartment avionics.
3
VALVE Light
Illuminated (amber) – equipment cooling valves are not in their commanded
position.
4
Overheat (OVHT) light
Illuminated (amber) – high temperature or low airflow in the equipment cooling
system.
5
SMOKE Light
Illuminated (amber) – smoke in the equipment cooling system.
Cargo Heating
Cargo Heat Panel
[Cargo Heat Panel shown with the BULK Cargo heat option installed.]
FWD
CARGO HEAT
AFT
BULK
ON
ON
ON
1
OVHT
OVHT
OVHT
2
OVERHEAD PANEL
Page 22
Boeing B767 - Systems Summary [Air Systems]
[Cargo Heat Panel shown without the BULK Cargo heat option installed.]
CARGO HEAT
FWD
AFT
ON
ON
1
OVHT
OVHT
2
OVERHEAD PANEL
1
CARGO HEAT Switches
ON – provides power for heat valves to cycle open and closed for automatic
temperature control
Off (ON not visible)– the heat valves are commanded closed
2
Cargo Heat Overheat (OVHT) Lights
Illuminated (amber) –
• cargo compartment temperature above standard control range
• shutoff valve signaled closed
Bulk Cargo Heat Panel
[Bulk Cargo Heat Panel shown with the optional NORM or VENT position
selector.]
BULK CARGO HEAT
NORM
VENT
1
ACCESSORY PANEL
1
BULK CARGO HEAT Selector
Bulk cargo heat switch must be on
NORM – standard cargo heating range
VENT –
• requests higher temperature control range than NORM
• turns on ventilating fan for bulk cargo compartment
Page 23
Boeing B767 - Systems Summary [Air Systems]
BULK CARGO HEAT
CARGO
ANIMAL
1
ACCESSORY PANEL
1
BULK CARGO HEAT Selector
Bulk cargo heat switch must be on
CARGO – standard cargo heating range.
ANIMAL –
• requests higher temperature control range than CARGO
• turns on ventilating fan for bulk cargo compartment.
Page 24
Boeing B767 - Systems Summary [Air Systems]
Pressurization System
Cabin Altitude Controls
1
CABIN ALTITUDE CONTROL
VALVE
OP
CLIMB
MANUAL
AUTO RATE
5
2
MIN
CL
MAX
DESCEND
LDG ALT
3
MODE SELECT
AUTO 2
AUTO 1
4
6
AUTO INOP
00340
MAN
7
OVERHEAD PANEL
1
Cabin Altitude MANUAL Control
Spring – loaded to center.
Controls cabin outflow valve position with the Cabin Altitude Mode Selector in
manual (MAN) mode.
CLIMB – moves outflow valve toward open.
DESCEND – moves outflow valve toward closed.
2
Outflow VALVE Position Indicator
OP – Open.
CL – Closed
3
Landing Altitude (LDG ALT) Indicator
Feet.
Displays selected landing altitude.
4
Landing Altitude (LDG ALT) Selector
Rotate – sets landing altitude indicator.
Page 25
Boeing B767 - Systems Summary [Air Systems]
5
Cabin Altitude AUTO RATE Control
Rotate –
• sets limit for cabin altitude rate of climb or descent during auto control
• index mark establishes approximately 500 fpm climb and 300 fpm
descent.
6
AUTO Inoperative (INOP) Light
Illuminated (amber) –
• AUTO 1 and AUTO 2 cabin altitude control functions are inoperative
• MAN mode is selected.
7
Cabin Altitude MODE SELECTOR
AUTO 1 –
• activates Auto 1 cabin altitude control for automatic operation
• outflow valve positioned automatically.
AUTO 2 –
• activates Auto 2 cabin altitude control for automatic operation
• outflow valve positioned automatically.
MAN (Manual) –
• outflow valve position is controlled by the cabin altitude MANUAL
control
• AUTO INOP light illuminates.
Cabin Altitude Indicators
CABIN
1
2
10
8
0
6
0
2
25
4
20
15
6
10 8
2
4
DIFF
PSI
ALT
1 2
0
3
1 2
FPM X
FT X
1000
RATE 1000
OVERHEAD PANEL
1
Cabin Differential Pressure Indicator
Cabin Altitude Rate
Feet per minute (fpm x 1,000).
Pounds per square inch (psi).
2
3
Cabin Altitude
Feet x 1,000.
Page 26
Boeing B767 - Systems Summary [Air Systems]
3
Cabin Altitude (CABIN ALT) Light
CABIN
ALT
1
CENTER FORWARD PANEL
1
Cabin Altitude Light
Illuminated (red) –
• cabin altitude exceeds 10,000 feet
• extinguishes when cabin altitude descends below 8,500 feet.
Cabin Altitude Light
1
CABIN
ALTITUDE
PRESS DIFF
LIMIT: T/O &
LDG.125 PSI
EQUIP COOLING
AUTO
STBY
OVRD
NO
COOLING
VALVE
OVHT
SMOKE
OVERHEAD PANEL
1
Cabin Altitude Light
Illuminated (red) –
• cabin altitude exceeds 10,000 feet
• extinguishes when cabin altitude descends below 8,500 feet.
Page 27
Boeing B767 - Systems Summary [Air Systems]
Bleed Air System
Bleed Air Control Panel
60
1
2
3
40
L ISLN
20
80
DUCT
PRESS
PSI
0
R ISLN
VALVE
VALVE
C ISLN
V
A
L
V
E
DUCT
LEAK
BLEED
D
U
C
T
OVHT
4
5
L
E
A
K
6
O
F
F
7
BLEED
8
OVHT
ADP
APU
L ENG
DUCT
LEAK
R ENG
V
A
L
V
E
9
10
O
F
F
11
OVERHEAD PANEL
1
Duct Pressure (DUCT PRESS) Indicators
Pounds per square inch (PSI).
2
Isolation (ISLN) Switches
On (bar in view) – commands isolation valves to open.
Off (bar not in view) – commands isolation valves to close.
3
Isolation VALVE Lights
Illuminated (amber) – isolation valve position disagrees with commanded
position.
4
DUCT LEAK Light
Illuminated (amber) – a high temperature bleed air leak is detected in the center
pneumatic duct.
Page 28
Boeing B767 - Systems Summary [Air Systems]
5
Engine (ENG) Bleed Air Switches
On (bar in view) – the engine bleed air valve opens when engine bleed air is
available.
Off (bar not in view) – valve is manually commanded closed.
6
Engine Bleed Air OFF Lights
Illuminated (amber) – engine bleed air valve is closed:
• automatically due to a system fault
• the switch is OFF
• the engine is not running.
7
DUCT LEAK Lights
Illuminated (amber) – a high temperature bleed air leak is detected in the left,
right, or engine strut pneumatic duct.
8
Engine BLEED Lights
Illuminated (amber) – the engine high pressure bleed air valve and/or pressure
regulating valves are open when they should be closed.
9
Engine Bleed Air Overheat (OVHT) Lights
Illuminated (amber) –
• engine bleed air overtemp
• engine bleed valves automatically closed.
10
APU Bleed Air Switch
On (bar in view) – the APU bleed air valve is automatically controlled
Off (bar not in view) – commands APU bleed air valve to close.
11
APU Bleed Air VALVE Light
Illuminated (amber) – APU bleed air valve position disagrees with commanded
position.
Page 29