Boeing B737NG - Air Systems

What systems need pneumatic power for operation?

APU, engine starting, air Conditioning and pressurization.

Wing anti-ice, APU and engine starting.

Air Conditioning, pressurization, wing anti-ice and APU.

Engine starting, air conditioning, pressurization, wing and engine anti-ice, hydraulic reservoirs and water tank pressurization.

Correct! Wrong!

From where does the Cabin Auto Controller get its inputs.

From the ADIRUs.

From the Captain’s CDU.

From the static ports.

From the EFIS control panel.

Correct! Wrong!

The ram air system provides cooling air for the:

Cargo area.

Packs

Heat exchangers.

Cargo area and packs.

Correct! Wrong!

Cruising at FL 370. The motorized Overboard Exhaust valve will open if:

Both pack switches are in AUTO and recirculation fan is ON.

Both pack switches are in AUTO and recirculation fan is OFF.

Both pack switches are in HIGH and recirculation fan is ON.

Either pack switches are in HIGH and recirculation fan is OFF.

Correct! Wrong!

While taxiing in, the controller drives the outflow valve slowly to the full open position depressurizing the cabin.

True.

False.

Correct! Wrong!

A DUCT OVERHEAT light only will cause:

The temperature mix valves to drive full cold.

A BLEED TRIP OFF.

The temperature mix valves to drive full hot.

An automatic shutdown of the pack.

Correct! Wrong!

Water tank pressurisation in flight is normally provided by:

5th and 9th stage air from the No. 1 engine.

Bleed air from the APU.

5th and 9th stage air from the No. 2 engine.

Correct! Wrong!

When both the AUTO FAIL light and the ALTN light illuminate:

Pressurization has automatically switched to the MAN system.

Pressurization has automatically switched to the ALTN system.

Pressurization has automatically switched to the opposite automatic controller.

Correct! Wrong!

One PACK light illuminates on recall only. What does it indicate?

The primary pack control has failed and the pack is now controlled by the standby pack control

There is a FOD in the RAM AIR intake forcing the pack to shut down.

Both temperature control valves have shut closed in the affected pack.

Both primary and secondary pack controls have failed.

Correct! Wrong!

During descent when the descent mode is activated:

Aircraft descends 0.50 below the selected FLT ALT.

Aircraft descends 0.25 psi below the selected LAND ALT.

Aircraft descends 0.50 psi below the selected LAND ALT.

Aircraft descends 0.25 psi below the selected FLT ALT.

Correct! Wrong!

The cabin pressure controller controls cabin pressure in the following modes: AUTO (automatic) - ALT (alternate) - MAN (manual).

All three modes use AC motor.

Automatic mode uses AC motor while the two other modes use DC motor.

All three modes use DC motor.

Automatic and alternate modes use AC motor while the manual mode use DC motor.

Correct! Wrong!

The maximum differential pressure is:

8.45 psi.

7.90 psi.

8.65 psi.

9.10 psi.

Correct! Wrong!

Cabin altitude is normally rate-controlled by the cabin pressure controller up to a cabin altitude of feet at the airplane maximum certified ceiling of feet.

8 000 ft and 41 000 ft.

7 500 ft and 41 000 ft.

12 000 ft and 41 000 ft.

10 000 ft and 41 000 ft.

Correct! Wrong!

The amount of fan air that is ducted through the pre-cooler is controlled by the:

Modulating and shut-off valve.

Thermostatic pre-cooler valve.

Ram air controller

Correct! Wrong!

Where is the forward outflow valve located?

Forward of the left hand air conditioning inlet.

Forward of the right hand air conditioning inlet.

There is no forward outflow valve.

In the nose landing gear bay.

Correct! Wrong!

Takeoff is allowed with Pack switches in HIGH, but landing is not permitted:

True.

False.

Correct! Wrong!

What is the position of the isolation valve when the ISOLATION VALVE switch is in AUTO?

The isolation valve is always open

The isolation valve is always closed.

Open when any Engine Bleed Air switch or Air Conditioning pack switch is positioned OFF.

The isolation valve automatically modulates between open & closed, depending on pneumatic load.

Correct! Wrong!

In MANUAL pressurization mode the outflow is driven by?

A motor supplied from DC standby bus.

Requires AC power from transfer bus 1.

A motor supplied from DC bus 1.

A motor supplied from DC bus 2.

Correct! Wrong!

What happens when the WING BODY OVHT TEST switch is pressed?

The amber PACK TRIP OFF Lights illuminate.

The amber WING-BODY OVERHEAT Lights illuminate.

The amber BLEED TRIP OFF Lights illuminate.

All statements are correct.

Correct! Wrong!

The recirculation fan system circulates air from the passenger cabin around thelining of the forward cargo compartment. When the overboard exhaust valve isclosed, exhaust air from the equipment cooling system is also diffused to the lining of the aft cargo compartment for additional inflight heating.

False.

True.

Correct! Wrong!

Forward cargo compartment only.

During preflight procedure the trim air switch is left in the OFF position and only one pack is selected ON for air conditioning. What is the consequence?

During single pack operation the zone temperature is controlled the same as during two pack operation.

With the TRIM AIR selected OFF, the pack attempts to produce an air temperature to satisfy the average temperature demands of all three zones.

If a passenger cabin zone trim air, or all trim air is lost, the forward and aft zone temperature demands will be averaged for control of the left pack.

Since the trim air is off both packs will average the temperature that satisfies the zone which requires the most cooling

Correct! Wrong!

If any individual zone is switched OFF, the Temperature Selector setting will be ignored by the temperature control system.

False.

True.

Correct! Wrong!

When does the amber DUAL BLEED Light illuminate?

When the APU bleed valve is open and the No.1 engine bleed switch is OFF.

When the APU bleed valve is open, the No.2 engine bleed switch is ON and the isolation valve is closed.

When the APU bleed valve is open.

When the APU bleed valve is open and the No.1 engine bleed switch is ON.

Correct! Wrong!

Zone Temperature Control - There are three zones: flight deck (CONT CAB), forward passenger cabin (FWD CAB) and aft passenger cabin (AFT CAB). Desired zone temperature is set by adjusting the individual Temperature Selectors. The selector range is approximately:

16 deg.C (61 deg.F) (18°C) to 25 deg.C (77 deg.F).

18 deg.C (65 deg.F) (18°C) to 30 deg.C (85 deg.F).

17 deg.C (63 deg.F) (18°C) to 26 deg.C (79 deg.F).

19 deg.C (66 deg.F) (18°C) to 29 deg.C (84 deg.F).

Correct! Wrong!

Due to a malfunction you are required to return to the airport of departure. To avoid the OFF SCHED DESCENT warning you reset the FLT ALT. What can you expect?

Nothing will happen and you will still get the OFF SCHED DESCENT warning.

The system will be recalculating the pressurization for the departure airport

The pressurization will increase its ventilation and possibly pressurization will be lost

The automatic abort capability for the departure airport is lost

Correct! Wrong!

The wing-body overheat light comes on. What is the related master caution warning?

As the light is in the proximity of the pilot’s perception there is no master caution for this condition.

OVERHEAD.

OVHT DET.

AIR COND.

Correct! Wrong!

Loss of airflow due to failure of an equipment cooling fan results in illumination of the related equipment cooling OFF light. Selecting the alternate fan should restore airflow and extinguish the OFF light within approximately _____.

20 seconds.

60 seconds.

3 minutes.

5 seconds.

Correct! Wrong!

What is the flight level limitation for DISPATCH with one pack INOP?

FL250.

FL180.

FL100.

FL410.

Correct! Wrong!

An illuminated BLEED TRIP OFF light indicates:

Too high temperature in bleed air duct and bleed air valve stays closes.

Too high temperature in bleed air duct and bleed air valve stays open.

Too high pressure in bleed air duct and bleed air valve stays open.

Too high temperature or pressure in bleed air duct and bleed air valve stays closes.

Correct! Wrong!

Given the scenario that the expected cruise level of FL310 was selected into the FLT ALT selector during preflight, but subsequently the aircraft climbed to FL390.

A differential pressure of 9.1 psi is maintained by the positive pressure relief valve.

A differential pressure of 6.1 psi is maintained by the positive and the negative pressure relief valves.

A differential pressure of 8.35 psi is maintained by the forward outflow valve

A differential pressure of 7.45 psi is maintained by the negative pressure relief valve.

Correct! Wrong!

Conditioned air from the left hand pack flows directly to the flight deck from the Mix Manifold.

False.

True.

Correct! Wrong!

The differential pressure of the cabin is limited by a pressure relief system - which of the following statements is correct?

There are two negative pressure relief valves, which limit the cabin pressure to 9.1 psi above ambient.

There is a negative pressure relief valve, which limits the cabin pressure to 9.1 psi above ambient.

There are two pressure relief valves which limit differential pressure to 9.1 psi.

There is an outflow valve which opens when cabin pressure reaches 9.1 psi above ambient.

Correct! Wrong!

A leak in the APU Bleed Air Duct will be indicated by:

Left WING‐BODY OVERHEAT light illuminated

APU BLEED light illuminated on overhead panel

Left and Right WING‐BODY OVERHEAT lights illuminated.

Right WING‐BODY OVERHEAT light illuminated.

Correct! Wrong!

When operating on the Standby Pack Controls, what temperatures will the packs be producing?

The flight deck required temperature will also be provided to the passenger cabin.

The trim air modulating valves close so no pack air is provided to the two cabin zones, only re-circulated air is provided.

An average temperature for the two cabin zones.

Left pack produces 18 deg.C (64 deg.F) , right pack produces 22 deg.C (72 deg.F).

Correct! Wrong!

In cruise the air conditioning ram air doors are:

Modulate as a function of airspeed.

Fully open.

Modulate between open and closed as required for pack temperature control.

Fully closed.

Correct! Wrong!

The amber OFF SCHEDULE DESCENT light illuminates. What does it indicate?

The pressurisation controller has failed and will automatically shift to manual.

The aircraft has descended before reaching the planned cruise altitude set in the altitude window.

The pressurization standby controller has failed and will automatically shift to STANDBY.

The main pressurization controller is unable to maintain pressurization and has to be manually shift to manual.

Correct! Wrong!

When pressing Master Caution Recall the CONT CAB amber ZONE TEMP light illuminates.

Due to failure of the primary flight deck temperature control, automatic switching to the backup system has occurred.

This indicates one PACK has overheated and has to be reset by pushing the trip reset button.

This indicates a failure of both the primary and standby temperature control systems.

This indicates that both temperature controllers will regulate the temperature to a preset value.

Correct! Wrong!

If all Temperature Selectors are positioned OFF, the pack controls will cause the left pack to maintain a fixed temperature of and the right pack to maintain as measured at the pack temperature sensor.

20 deg.C (68 deg.F) and 18 deg.C (65 deg.F)

17 deg.C (65 deg.F) and 24 deg.C (72 deg.F)

18 deg.C (65 deg.F) and 22 deg.C (72 deg.F)

24 deg.C (75 deg.F) and 18 deg.C (65 deg.F)

Correct! Wrong!

What is the purpose of the recirculation fans?

If increased smoke removal is required.

To decrease the air conditioning system pack load.

To operate as air mixers in the mix manifold.

To increase the pressure in the cabin.

Correct! Wrong!

The packs produce the coolest temperature selected in any of the zones, with the other zones temperature controlled by adding hot trim air to produce the required temperature.

False.

True.

Correct! Wrong!

What is the primary source of conditioned air for the cockpit?

Both packs.

The right pack.

Ground air.

The left pack.

Correct! Wrong!

The isolation valve is:

AC controlled and pneumatically operated.

DC operated.

AC operated.

Correct! Wrong!

Where are the bleed trip sensors installed?

Sensors are positioned on both sides of the engine bleed air valve.

On the bleed air duct prior to the pack valve.

On the engine side of the engine bleed air valve.

On the 9th Stage bleed air line.

Correct! Wrong!

Illumination of the amber BLEED TRIP OFF light indicates what valve has automatically closed?

Modulating and Shutoff valve.

Engine Bleed Air valve.

Isolation valve.

5th valve of the compressor section.

Correct! Wrong!

What happens to engine fan air that is used to cool engine bleed air?

It is ducted into the crossbleed manifold.

It is ducted into the pneumatic manifold.

It is discharged overboard.

It is ducted into the 5th stage compressor section.

Correct! Wrong!

The altitude warning horn is:

A continuous warning horn.

An intermittent warning horn.

An intermittent warning horn accompanied by a Master Caution warning.

A continuous warning horn accompanied by a Master Caution warning.

Correct! Wrong!

When will the descent mode be activated in the pressurization system?

When retard is announced in the FMA.

When within 15 000 feet of the landing airport.

When TD is reached.

When descending 0.25psi below the selected flight altitude.

Correct! Wrong!

The amber DUAL BLEED Light is illuminated before starting engines. What should you do?

Do not start the engines, check MEL.

Nothing. This is normal condition before engine start.

Shut down the APU and use a pneumatic ground cart for engine start.

Do not start the engines, call Maintenance.

Correct! Wrong!

The AUTO mode is active. The amber AUTO FAIL light illuminates when:

The pressurization controller is moved to ALTN.

Correct! Wrong!

The pneumatic duct pressure gauge:

Indicates pressure in left and right pneumatic ducts.

Indicates pressure available for engine anti-icing.

Is DC powered.

Correct! Wrong!

The recirculation fans:

Provide overheat detection downstream of the packs.

Are driven by a DC motor.

Reduce air conditioning pack load.

Increase airflow at greater cabin differential pressures.

Correct! Wrong!

The ram air system deflector doors:

Extend during slow flight when flaps are not retracted.

Are always extended when the gear is down.

Modulate between fully extended and retracted through the entire flight.

Extend on the ground only.

Correct! Wrong!

Where are the wing-body overheat sensors located?

Engine struts, wing inboard leading edges, air conditioning bays, APU bleed duct, keel beam.

Engine struts, wing leading edge slats, air conditioning bays, APU duct, keel beam.

Engine cowl lips, wing leading edge slats, air conditioning bays, electronic equipment bay, APU bleed duct.

Engine cowling lips, wing leading edge slats, air conditioning bays, APU compartment, keel beam.

Correct! Wrong!

The DUAL BLEED light is illuminated. Engine thrust:

Should be limited to 40% N1.

Is unlimited. Dual bleed light is advisory only.

Should be limited to idle.

Correct! Wrong!

Overheat detection is provided by temperature sensors located:

Downstream of the packs.

In the mix manifold.

Downstream of the packs and the mix manifold.

Downstream of the packs, the trim air valve and the mix manifold.

Correct! Wrong!

What causes the amber PACK TRIP OFF Light to illuminate?

Compressor outlet duct temperature has exceeded limits

All statements are correct.

Turbine inlet duct temperature has exceeded limits.

Main distribution duct temperature has exceeded limits.

Correct! Wrong!

If all zone and primary pack controls fail, how is cabin temperatures controlled?

A fixed cabin temperature will be produced in this situation 24 deg.C (75 deg.F) from the left pack, and 18 deg.C (64 deg.F) from the right pack.

The cabin temperatures cannot be controlled in this situation.

The last settings before the failure will be maintained until the packs are selected OFF.

The standby pack controls command the packs to produce the average temperature demand of the 2 passenger cabin zones.

Correct! Wrong!

The amber DUAL BLEED light indicates apossible APU back pressure condition and thrust must be limited to IDLE.

False.

True.

Correct! Wrong!

Engine bleed air is obtained from:

4th and 9th stage of the compressor section.

5th and 8th stage of the compressor section.

4th and 8th stage of the compressor section.

5th and 9th stage of the compressor section.

Correct! Wrong!

How are the Engine Bleed Air valves powered?

They are pneumatically activated and DC operated.

They are AC activated and pneumatically operated.

They are DC activated and pneumatically operated.

They are pneumatically activated and AC operated.

Correct! Wrong!

The 9th stage modulating and shut-off valve:

Will open if the 5th stage air is insufficient in maintaining proper pressure.

Is open at all times irrespective of 5th stage air pressure output.

Will open if the APU is insufficient in maintaining proper pressure.

Correct! Wrong!

With a ground pneumatic source connected and the isolation valve switch selected to CLOSE.

The pneumatic pressure would be indicated by the left hand pointer on the pneumatic duct pressure indicator.

The pneumatic pressure would be indicated by both the left and right pointers on the pneumatic duct pressure indicator.

The pneumatic pressure would be indicated by the right hand pointer on the pneumatic duct pressure indicator.

Correct! Wrong!

What are the causes of an amber AUTO FAIL light?

Loss of DC power or controller fault.

Excessive rate of cabin pressure change or high cabin altitude (above 15,800 ft).

All statements are correct.

Outflow valve control fault or excessive differential pressure.

Correct! Wrong!

The air data inertial reference units (ADIRUs) provides ambient static pressure,baro corrected altitude, non corrected altitude and calibrated airspeed to bothautomatic controllers. The ADIRUs receive barometric corrections from the Captain's and First Officer's BARO reference selectors. The automatic controllers also receive:

Throttle position from both stall management computers and signals from the IRS.

Throttle position from both stall management computers.

Throttles position and signals from the IRS.

Throttle position from both stall management computers and signals from the air-ground sensors.

Correct! Wrong!

Automatic switching to 'high air flow' occurs if both engine bleed air switches are OFF and the APU bleed air switch is ON, regardless of flap position, air-ground status or number of packs operating.

False.

True.

Correct! Wrong!

The right WING-BODY OVERHEAT light is illuminated, what area is affected?

Right engine strut.

Left aircond bay.

APU bleed duct.

The keel beam.

Correct! Wrong!

A ZONE TEMP light may be reset by the trip reset switch on the Bleed Panel.

False. This reset switch is for BLEED TRIP OFF only.

True.

False. This reset is only for resetting a PACK trip.

False. This reset switch is only for PACK and BLEED TRIP OFF resets.

Correct! Wrong!

The TRIP RESET switch is pushed to reset a PACK, WING-BODY OVERHEAT and BLEED TRIP OFF, it isolates the associated valve and extinguishes the alert.

True.

False.

Correct! Wrong!

Deflector doors are installed forward of the ram air inlet doors to prevent slush ingestion prior to liftoff and after touchdown. Deflector doors extend when activated:

Pneumatically.

Hydraulically when extended the main landing gear

Electrically in the air and pneumatically on ground

Electrically by the air-ground safety sensor

Correct! Wrong!

An amber AUTOFAIL indication will illuminate if one or more of the following conditions occur:

Loss of AC power for more than 15 seconds. Main outflow valve DC motor fails or if the cabin altitude exceeds 13,875 ft.

A single controller failure when the 'ALTN' light is also illuminated.

The cabin altitude exceeds 10,000 ft.

The cabin altitude exceeds 13,875 ft with the loss of AC power.

Correct! Wrong!

APU bleed air used to start NO.1 engine is:

Routed via the No. 1 engine bleed air valve to the No.1 engine starter valve.

Controlled by the modulating and shut-off valve.

Routed direct to the No.1 engine starter valve.

Correct! Wrong!

Where do the AUTO mode controllers receive their barometric information from?

The captain's pitot static system.

The FO's pitot static system.

The two pitot static systems.

The ADIRUs.

Correct! Wrong!

The cabin will automatically pressurize to 0.125 PSID on the ground when:

When the aircraft goes into the air mode of the air-ground sensor.

Engine thrust is increased towards takeoff thrust.

When the aircraft goes into the ground mode of the air-ground sensor.

When the PSEU is activated.

Correct! Wrong!

Cabin air outflow is controlled by the outflow valve and the overboard exhaustvalve. A small amount is also exhausted through toilet and galley vents, miscellaneous fixed vents, and by seal leakage.

False.

True.

Correct! Wrong!

Engine bleed air pressure is controlled by means of the bleed air valve which acts as both a shutoff and pressure regulating valve.

False.

True.

Correct! Wrong!

The motorized Exhaust valve:

All statements are correct.

Allows for increased ventilation in the smoke removal configuration.

Serves as backup to the outflow valve if the outflow valve fails.

Is normally open in pressurized flights above 8,000 feet.

Correct! Wrong!

How many Trim Air Pressure Regulators are there in the Air Conditioning system?

There are no Trim Air Pressure Regulators, only Trim Air Modulating valves.

Two.

Three.

One.

Correct! Wrong!

If all zone controls and primary pack controls fail, the standby pack controlscommand the packs to produce air temperatures which will satisfy the averagetemperature demand of the two cabin zones. The trim air modulating valves will:

Open.

Close.

Correct! Wrong!

If a PACK light can be reset by the TRIP RESET switch then:

The fault was caused by an overheat trip or by a controller fault.

The pack should be selected off as per the QRH.

The fault was caused by a controller fault.

The fault was caused by an overheat trip.

Correct! Wrong!

The APU is capable of supplying bleed air for two packs on the ground, or one pack in flight.

True.

False.

Correct! Wrong!

Boeing 737NG – Air Systems

Quiz

Boeing B737NG - Air Systems

What systems need pneumatic power for operation?

From where does the Cabin Auto Controller get its inputs.

The ram air system provides cooling air for the:

Cruising at FL 370. The motorized Overboard Exhaust valve will open if:

While taxiing in, the controller drives the outflow valve slowly to the full open position depressurizing the cabin.

A DUCT OVERHEAT light only will cause:

Water tank pressurisation in flight is normally provided by:

When both the AUTO FAIL light and the ALTN light illuminate:

One PACK light illuminates on recall only. What does it indicate?

During descent when the descent mode is activated:

The cabin pressure controller controls cabin pressure in the following modes: AUTO (automatic) - ALT (alternate) - MAN (manual).

The maximum differential pressure is:

Cabin altitude is normally rate-controlled by the cabin pressure controller up to a cabin altitude of ____ feet at the airplane maximum certified ceiling of ____feet.

The amount of fan air that is ducted through the pre-cooler is controlled by the:

Where is the forward outflow valve located?

Takeoff is allowed with Pack switches in HIGH, but landing is not permitted:

What is the position of the isolation valve when the ISOLATION VALVE switch is in AUTO?

In MANUAL pressurization mode the outflow is driven by?

What happens when the WING BODY OVHT TEST switch is pressed?

During preflight procedure the trim air switch is left in the OFF position and only one pack is selected ON for air conditioning. What is the consequence?

If any individual zone is switched OFF, the Temperature Selector setting will be ignored by the temperature control system.

When does the amber DUAL BLEED Light illuminate?

Zone Temperature Control - There are three zones: flight deck (CONT CAB), forward passenger cabin (FWD CAB) and aft passenger cabin (AFT CAB). Desired zone temperature is set by adjusting the individual Temperature Selectors. The selector range is approximately:

Due to a malfunction you are required to return to the airport of departure. To avoid the OFF SCHED DESCENT warning you reset the FLT ALT. What can you expect?

The wing-body overheat light comes on. What is the related master caution warning?

Loss of airflow due to failure of an equipment cooling fan results in illumination of the related equipment cooling OFF light. Selecting the alternate fan should restore airflow and extinguish the OFF light within approximately _____.

What is the flight level limitation for DISPATCH with one pack INOP?

An illuminated BLEED TRIP OFF light indicates:

Given the scenario that the expected cruise level of FL310 was selected into the FLT ALT selector during preflight, but subsequently the aircraft climbed to FL390.

Conditioned air from the left hand pack flows directly to the flight deck from the Mix Manifold.

The differential pressure of the cabin is limited by a pressure relief system - which of the following statements is correct?

A leak in the APU Bleed Air Duct will be indicated by:

When operating on the Standby Pack Controls, what temperatures will the packs be producing?

In cruise the air conditioning ram air doors are:

The amber OFF SCHEDULE DESCENT light illuminates. What does it indicate?

When pressing Master Caution Recall the CONT CAB amber ZONE TEMP light illuminates.

If all Temperature Selectors are positioned OFF, the pack controls will cause the left pack to maintain a fixed temperature of ____ and the right pack to maintain ____ as measured at the pack temperature sensor.

What is the purpose of the recirculation fans?

The packs produce the coolest temperature selected in any of the zones, with the other zones temperature controlled by adding hot trim air to produce the required temperature.

What is the primary source of conditioned air for the cockpit?

The isolation valve is:

Where are the bleed trip sensors installed?

Illumination of the amber BLEED TRIP OFF light indicates what valve has automatically closed?

What happens to engine fan air that is used to cool engine bleed air?

The altitude warning horn is:

When will the descent mode be activated in the pressurization system?

The amber DUAL BLEED Light is illuminated before starting engines. What should you do?

The AUTO mode is active. The amber AUTO FAIL light illuminates when:

The pneumatic duct pressure gauge:

The recirculation fans:

The ram air system deflector doors:

Where are the wing-body overheat sensors located?

The DUAL BLEED light is illuminated. Engine thrust:

Overheat detection is provided by temperature sensors located:

What causes the amber PACK TRIP OFF Light to illuminate?

If all zone and primary pack controls fail, how is cabin temperatures controlled?

The amber DUAL BLEED light indicates apossible APU back pressure condition and thrust must be limited to IDLE.

Engine bleed air is obtained from:

How are the Engine Bleed Air valves powered?

The 9th stage modulating and shut-off valve:

With a ground pneumatic source connected and the isolation valve switch selected to CLOSE.

What are the causes of an amber AUTO FAIL light?

Automatic switching to 'high air flow' occurs if both engine bleed air switches are OFF and the APU bleed air switch is ON, regardless of flap position, air-ground status or number of packs operating.

The right WING-BODY OVERHEAT light is illuminated, what area is affected?

A ZONE TEMP light may be reset by the trip reset switch on the Bleed Panel.

The TRIP RESET switch is pushed to reset a PACK, WING-BODY OVERHEAT and BLEED TRIP OFF, it isolates the associated valve and extinguishes the alert.

Deflector doors are installed forward of the ram air inlet doors to prevent slush ingestion prior to liftoff and after touchdown. Deflector doors extend when activated:

An amber AUTOFAIL indication will illuminate if one or more of the following conditions occur:

APU bleed air used to start NO.1 engine is:

Where do the AUTO mode controllers receive their barometric information from?

The cabin will automatically pressurize to 0.125 PSID on the ground when:

Cabin air outflow is controlled by the outflow valve and the overboard exhaustvalve. A small amount is also exhausted through toilet and galley vents, miscellaneous fixed vents, and by seal leakage.

Engine bleed air pressure is controlled by means of the bleed air valve which acts as both a shutoff and pressure regulating valve.

The motorized Exhaust valve:

How many Trim Air Pressure Regulators are there in the Air Conditioning system?

If all zone controls and primary pack controls fail, the standby pack controlscommand the packs to produce air temperatures which will satisfy the averagetemperature demand of the two cabin zones. The trim air modulating valves will:

If a PACK light can be reset by the TRIP RESET switch then:

The APU is capable of supplying bleed air for two packs on the ground, or one pack in flight.

Cabin altitude is normally rate-controlled by the cabin pressure controller up to a cabin altitude of feet at the airplane maximum certified ceiling of feet.

If all Temperature Selectors are positioned OFF, the pack controls will cause the left pack to maintain a fixed temperature of and the right pack to maintain as measured at the pack temperature sensor.