Air Systems DO NOT USE FOR FLIGHT

B767 Air Systems DO NOT USE FOR FLIGHT

2.20 Air Systems-Air onditioning System Description Introduction to Air onditioning 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 onditioning 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 onditioning Automatic Mode ith the pack selector in the position, pack output temperature is determined by the left and right cabin temperature controllers: Air onditioning Standby Mode ith the pack selector in the standby mode, pack output temperature is determined by the position of the pack selector: N (normal) - constant, moderate temperature (cool) - full cold (warm) - full warm. Ground onditioned Air Operation hen 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

Pack Non Normal Operation Pack control, fault detection, and overheat protection are all automatic. The pack light illuminates and the EIAS advisory message L or R PAK TEMP displays for all pack control system faults and overheats. hen 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 PAK light illuminates and the EIAS advisory message L or R PAK displays in addition to the PAK TEMP indications. If the 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 PAK RESET switch. Air Distribution onditioned 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 light illuminates and the EIAS advisory message L or R REIR FAN displays whenever a recirculation fan fails or is not operating. A slight increase in fuel consumption occurs for each fan that is. Temperature ontrol 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

A compartment light illuminates, and the EIAS advisory message FLT DEK TEMP, FD ABIN TEMP, MID ABIN TEMP, or AFT ABIN TEMP displays to indicate: zone temperature controller failure trim air switch is compartment temperature control is in the position (FD, MID, and AFT AB only). Temperature ontrol ith 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 light illuminates and the EIAS 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

Air onditioning System Schematic OMPT TEMP FLT DK FD AB MID AB AFT AB MAN TRIM AIR L REIR FAN R ON ON ON FLT DK L PAK RESET R PAK RESET PAK MAN PAK FLT DK TEMPERATURE ONTROL INDIATORS TRANSPOSED FROM PANEL POSITION TO IMPROVE FUNTIONAL DESRIPTION. SUPPLY AIR N S T B Y N S T B Y EXHAUST AIR PNEUMATI SUPPLY PNEUMATI 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

Equipment ooling System Forward Equipment ooling 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 OOLING selector in. 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 EIAS advisory message FD EQPT VAL displays if the system valves fail to reconfigure during automatic operation. Placing the EQUIP OOLING 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 EIAS advisory message FD EQPT OVHT displays if low airflow or high temperature is sensed. Placing the EQUIP OOLING selector in STBY may correct the condition by reconfiguring the system. The SMOKE light illuminates and the EIAS advisory message FD EQPT SMOKE displays if smoke is sensed in the forward equipment cooling ducts. Placing the EQUIP OOLING selector in OVRD allows conditioned air to be drawn in reverse through the system by differential pressure and exhausted overboard. The NO OOLING light illuminates and the EIAS caution message FD EQPT OOLING displays if no cooling airflow is sensed after selecting OVRD. argo 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

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 ). Bulk argo Heat Selector [hen the Bulk argo Heat option is installed, the Bulk argo Heat Panel will contain either the NORM/VENT selector switch or the ARGO/ANIMAL selector switch.] A BULK ARGO HEAT selector allows a higher temperature to be selected for the bulk compartment. ith the selector in the NORM position, the bulk compartment operates the same as the forward and aft compartments. ith the selector in the VENT position, the bulk compartment is maintained above approximately 65 F (8 ), and a vent fan draws cabin discharge air into the compartment. A BULK ARGO HEAT selector allows a higher temperature to be selected for the bulk compartment. ith the selector in the ARGO position, the bulk compartment operates the same as the forward and aft compartments. ith the selector in the ANIMAL position, the bulk compartment is maintained above approximately 65 F (8 ), and a vent fan draws cabin discharge air into the compartment. Non-Normal Operation [This paragraph applies to aircraft without the Bulk argo Heat option.] The cargo heat switch OVHT light illuminates, and the EIAS advisory message FD or AFT ARGO 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 ). hen the compartment temperature decreases below the overheat temperature setting, the OVHT light extinguishes, the EIAS message is removed, and the compartment shutoff valve re opens. [This paragraph applies to aircraft with the Bulk argo Heat option.] The cargo heat switch OVHT light illuminates and the EIAS advisory message FD, AFT or BULK ARGO 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 ). hen the compartment temperature decreases below the overheat temperature setting, the OVHT light extinguishes, the EIAS message is removed, and the compartment shutoff valve re opens. Page 7

2.30 Air Systems-Pressurization System Description Introduction to Pressurization System abin 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 or 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. limb 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. ruise 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

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 0,000 feet, the ABIN ALT and ABIN ALTITUDE lights illuminate and the EIAS warning message ABIN ALTITUDE displays. The lights extinguish and the EIAS message blanks when the cabin altitude descends below 8,500 feet. The light illuminates and the EIAS caution message ABIN displays when automatic pressurization control fails or when cabin altitude MODE SELET 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,000 feet. The manual mode has no auto closure feature. To operate the pressurization system manually: set the cabin altitude MODE SELET to MAN hold the cabin altitude MANUAL control to LIMB to move the outflow valve toward open and cause the cabin altitude to climb hold the cabin altitude MANUAL control to DESEND to move the outflow valve toward closed and cause the cabin altitude to descend. Page 9

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 light illuminates and the EIAS advisory message L or R ENG BLEED displays when the engine bleed air valve is closed for a system fault. The OVHT light illuminates and the EIAS advisory message L or R ENG BLD OVHT displays when the engine bleed air temperature is excessive. The BLEED light illuminates and the EIAS 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 EIAS advisory message L or R ENG PRV displays when the pressure regulating valve is open when commanded closed. Page 0

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 7,000 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 EIAS 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. heck 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 EIAS advisory message, L or R BLD ISLN VAL displays when the bleed isolation valve position disagrees with the commanded position. The DUT LEAK light illuminates and the EIAS caution message L or R BLD DUT LEAK, BODY DUT LEAK or STRUT DT LEAK displays when a high temperature bleed air leak is detected. Page

Bleed Air System Schematic L PAK R PAK GROUND PNEUMATI L ISLN 60 80 DUT 40 PRESS PSI 20 0 R ISLN FD ARGO HEAT VALVE VALVE ISLN L ING ANTI-IE DUT LEAK V A L V E DUT LEAK R ING ANTI-IE BLEED OVHT D L U E A T K ADP BLEED OVHT L HYD RES HYD RES AFT ARGO HEAT BULK ARGO HEAT R HYD RES L ENG APU R ENG O F F V A L V E O F F L THRUST REV R THRUST REV ENGINE ANTI-IE APU ENGINE ANTI-IE PRV PRV STARTER LP LP STARTER HPSOV HPSOV PANEL FLO LINES FLO LINES NOT ON PANEL Page 2

L PAK R PAK GROUND PNEUMATI L ISLN 60 80 DUT 40 PRESS PSI 20 0 R ISLN FD ARGO HEAT VALVE VALVE ISLN L ING ANTI-IE DUT LEAK V A L V E DUT LEAK R ING ANTI-IE BLEED OVHT D L U E A T K ADP BLEED OVHT L HYD RES HYD RES AFT ARGO HEAT BULK ARGO HEAT R HYD RES L ENG APU R ENG O F F V A L V E O F F ENGINE ANTI-IE APU ENGINE ANTI-IE PRV PRV STARTER LP LP STARTER HPSOV HPSOV PANEL FLO LINES FLO LINES NOT ON PANEL Page 3

2.50 Air Systems-Air Systems EIAS Messages Air Systems EIAS Messages The following EIAS messages can be displayed. Message Level Light Aural ondition APU BLEED VAL Advisory VALVE APU bleed valve position disagrees with the commanded position. L BLD DUT LEAK R BLD DUT LEAK BODY DUT LEAK BLD ISLN VAL L BLD ISLN VAL R BLD ISLN VAL aution DUT LEAK Beeper A high temperature bleed air leak is detected. Advisory VALVE Bleed isolation valve position disagrees with the commanded position. ABIN ALTITUDE arning ABIN ALTITUDE, ABIN ALT ABIN aution AFT ABIN TEMP FD ABIN TEMP MID ABIN TEMP Siren Beeper abin altitude excessive. Automatic pressurization control has failed or the cabin altitude mode selector is in manual. Advisory A fault in the zone temperature controller, compartment temperature control is in the position, or trim air switch. [This EIAS message applies to aircraft with the Bulk argo Heat option.] AFT ARGO OVHT Advisory OVHT argo compartment BULK ARGO temperature above OVHT standard control range. FD ARGO OVHT Page 4

Message Level Light Aural ondition [This EIAS message applies to aircraft without the Bulk argo Heat option.] AFT ARGO OVHT Advisory OVHT argo compartment FD ARGO OVHT temperature above standard control range. L ENG BLEED R ENG BLEED L ENG BLD OVHT R ENG BLD OVHT L ENG HPSOV R ENG HPSOV L ENG PRV R ENG PRV FD EQPT OOLING Advisory Engine bleed air valve is closed for a system fault. 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. aution NO OOLING Beeper FD EQPT OVHT Advisory OVHT Ground crew call horn on ground OVRD selected and no reverse airflow detected through the E/E compartment avionics. High temperature or low airflow in equipment cooling system. FD EQPT SMOKE Advisory SMOKE Smoke detected in the forward equipment cooling ducts. FD EQPT VAL Advisory VALVE An equipment cooling valve not in commanded position. FLT DEK TEMP Advisory A fault in the zone temperature controller or trim air switch. L PAK R PAK L PAK TEMP R PAK TEMP Advisory PAK Pack valve is closed. Advisory Automatic control system fault or overheat. Page 5

Message Level Light Aural ondition L REIR FAN R REIR FAN L STRUT DT LEAK R STRUT DT LEAK Advisory Fan is failed or not operating. aution DUT LEAK Beeper A high temperature bleed air leak is detected. TRIM AIR Advisory Trim air switch. Page 6

2.0 Air Systems-ontrols and Indicators Air onditioning System Air onditioning ontrol Panel [Air onditioning ontrol Panel shown without the Gasper Fan Switch option.] OMPT TEMP 2 FD AB MID AB AFT AB 3 4 TRIM AIR ON L - REIR FAN - R ON ON 0 5 FLT DK 6 2 7 8 9 L PAK RESET PAK N S T B Y MAN R PAK RESET PAK N S T B Y 3 4 OVERHEAD PANEL Page 7

[Air onditioning ontrol Panel shown with the Gasper Fan Switch option.] OMPT TEMP 2 FD AB MID AB AFT AB 3 4 TRIM AIR ON L - REIR FAN - R ON ON 0 5 6 5 6 GASPER ON FLT DK 2 7 8 9 L PAK RESET PAK N S T B Y MAN R PAK RESET PAK N S T B Y 3 4 OVERHEAD PANEL ompartment Temperature (OMPT TEMP) Indicators Displays actual temperature sensed in the compartment. 2 ompartment Temperature Inoperative () Lights Illuminated (amber) fault in the zone temperature controller the ompartment Temperature ontrol is the trim air switch is. Page 8

3 ompartment Temperature ontrols provides automatic compartment temperature control rotating the control toward (cool) or (warm) sets the desired temperature between 8 degrees and 30 degrees. closes the compartment trim air valve the compartment temperature 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 Light Illuminated (amber) the TRIM AIR switch is off. 6 Flight Deck (FLT DK) Temperature Inoperative () Light Illuminated (amber) fault in the zone temperature controller. the trim air switch is. 7 PAK RESET Switches Push resets an overheated pack if the pack has cooled to a temperature below the overheat level. 8 Pack Inoperative () Light Illuminated (amber) the pack is overheated fault in the automatic control system. 9 PAK Lights Illuminated (amber) pack valve is closed. 0 Recirculation Fan (REIR FAN) Switches ON the recirculation fan operates Off (ON not visible) the recirculation fan does not operate. Page 9

Recirculation Fan Inoperative () Lights Illuminated (amber) the recirculation fan is failed or is not operating. the REIR FAN switch is off. 2 Flight Deck Trim Air Valve Position Indicator (cool) valve closed. (warm) valve open. 3 Flight Deck ompartment Temperature ontrol provides automatic flight deck temperature control rotating the control toward (cool) or (warm) sets the desired temperature between 8 degrees and 30 degrees. MAN provides manual control of compartment trim air valve spring loaded to the 6 o clock position in this sector. 4 PAK ontrol Selectors closes the pack valve. the pack is automatically controlled. STBY N (normal) regulates the pack outlet temperature to a constant, moderate temperature. (cool) sets the pack to full cold operation. (warm) sets the pack to full warm operation. 5 GASPER Fan Switch [Gasper Fan Switch and 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. 6 Gasper Fan light Illuminated (amber) the GASPER fan switch is ON but the gasper fan is not operating. Page 20

Shoulder and Foot Heaters HEATERS FOOT SHOULDER HI LO 2 LEFT AND RIGHT SIDEALL 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. LO the electric heater adds heat at low setting to the conditioned air flowing to the rudder pedal area in flight only. 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. LO the electric heater adds heat at low setting to the conditioned air flowing to the side window area in flight only. the electric heater is not operating (no heat added to the conditioned air flowing to the side window area). Equipment ooling Panel 2 ABIN ALTITUDE PRESS DIFF LIMIT: T/O & LDG.25 PSI NO OOLING EQUIP OOLING STBY OVRD VALVE OVHT SMOKE 3 4 5 OVERHEAD PANEL Page 2

Equipment (EQUIP) OOLING Selector 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 OOLING 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. argo Heating argo Heat Panel [argo Heat Panel shown with the BULK argo heat option installed.] FD ARGO HEAT AFT BULK ON ON ON OVHT OVHT OVHT 2 OVERHEAD PANEL Page 22

[argo Heat Panel shown without the BULK argo heat option installed.] FD ARGO HEAT AFT ON OVHT ON OVHT 2 ARGO HEAT Switches OVERHEAD PANEL 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 argo Heat Overheat (OVHT) Lights Illuminated (amber) cargo compartment temperature above standard control range shutoff valve signaled closed Bulk argo Heat Panel [Bulk argo Heat Panel shown with the optional NORM or VENT position selector.] BULK ARGO HEAT NORM VENT AESSORY PANEL BULK ARGO 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

BULK ARGO HEAT ARGO ANIMAL AESSORY PANEL BULK ARGO HEAT Selector Bulk cargo heat switch must be on ARGO standard cargo heating range. ANIMAL requests higher temperature control range than ARGO turns on ventilating fan for bulk cargo compartment. Page 24

Pressurization System abin Altitude ontrols ABIN ALTITUDE ONTROL 2 OP L VALVE LIMB DESEND MANUAL MIN RATE MAX 5 3 4 LDG ALT 00340 MODE SELET 2 MAN 6 7 OVERHEAD PANEL abin Altitude MANUAL ontrol Spring loaded to center. ontrols cabin outflow valve position with the abin Altitude Mode Selector in manual (MAN) mode. LIMB moves outflow valve toward open. DESEND moves outflow valve toward closed. 2 Outflow VALVE Position Indicator OP Open. L losed 3 Landing Altitude (LDG ALT) Indicator Feet. Displays selected landing altitude. 4 Landing Altitude (LDG ALT) Selector Rotate sets landing altitude indicator. Page 25

5 abin Altitude RATE ontrol 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 Inoperative () Light Illuminated (amber) and 2 cabin altitude control functions are inoperative MAN mode is selected. 7 abin Altitude MODE SELETOR activates Auto cabin altitude control for automatic operation outflow valve positioned automatically. 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 light illuminates. abin Altitude Indicators ABIN 2 0 0 2 8 6 4 0 25 2 20 4 50 6 8 2 0 2 FT X DIFF PSI ALT 000 RATE FPM X 000 3 OVERHEAD PANEL abin Differential Pressure Indicator Pounds per square inch (psi). 2 abin Altitude Feet x,000. Page 26 3 abin Altitude Rate Feet per minute (fpm x,000).

3 abin Altitude (ABIN ALT) Light ABIN ALT ENTER FORARD PANEL abin Altitude Light Illuminated (red) cabin altitude exceeds 0,000 feet extinguishes when cabin altitude descends below 8,500 feet. abin Altitude Light ABIN ALTITUDE PRESS DIFF LIMIT: T/O & LDG.25 PSI NO OOLING EQUIP OOLING STBY OVRD VALVE OVHT SMOKE OVERHEAD PANEL abin Altitude Light Illuminated (red) cabin altitude exceeds 0,000 feet extinguishes when cabin altitude descends below 8,500 feet. Page 27

Bleed Air System Bleed Air ontrol Panel 2 3 L ISLN VALVE 60 80 DUT 40 PRESS PSI 20 0 R ISLN VALVE ISLN 4 5 6 DUT LEAK BLEED OVHT L ENG O F F V A L V E D L U E A T K V A L V E APU ADP O F F DUT LEAK BLEED OVHT R ENG 7 8 9 0 OVERHEAD PANEL Duct Pressure (DUT 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 DUT LEAK Light Illuminated (amber) a high temperature bleed air leak is detected in the center pneumatic duct. Page 28

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 Lights Illuminated (amber) engine bleed air valve is closed: automatically due to a system fault the switch is the engine is not running. 7 DUT 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. 0 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. APU Bleed Air VALVE Light Illuminated (amber) APU bleed air valve position disagrees with commanded position. Page 29