Boeing B737NG - Air Systems

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

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

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.

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

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?

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

The system will be recalculating the pressurization for the departure airport

The automatic abort capability for the departure airport is lost

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

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 or pressure 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.

Correct! Wrong!

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

Ground air.

The right pack.

Both packs.

The left pack.

Correct! Wrong!

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

False.

True.

Correct! Wrong!

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

Isolation valve.

Engine Bleed Air valve.

Modulating and Shutoff 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 5th stage compressor section.

It is ducted into the pneumatic manifold.

It is ducted into the crossbleed manifold.

It is discharged overboard.

Correct! Wrong!

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

Both primary and secondary pack controls have failed.

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

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

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

Correct! Wrong!

What causes the amber PACK TRIP OFF Light to illuminate?

Turbine inlet duct temperature has exceeded limits.

Main distribution duct temperature has exceeded limits.

Compressor outlet duct temperature has exceeded limits

All statements are correct.

Correct! Wrong!

A DUCT OVERHEAT light only will cause:

The temperature mix valves to drive full cold.

A BLEED TRIP OFF.

An automatic shutdown of the pack.

The temperature mix valves to drive full hot.

Correct! Wrong!

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

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

The cabin temperatures cannot be controlled in this situation.

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

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.

Correct! Wrong!

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

Routed direct to the No.1 engine starter valve.

Controlled by the modulating and shut-off valve.

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

Correct! Wrong!

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

Pressurization has automatically switched to the opposite automatic controller.

Pressurization has automatically switched to the ALTN system.

Pressurization has automatically switched to the MAN system.

Correct! Wrong!

During descent when the descent mode is activated:

Aircraft descends 0.25 psi below the selected FLT ALT.

Aircraft descends 0.25 psi below the selected LAND ALT.

Aircraft descends 0.50 below the selected FLT ALT.

Aircraft descends 0.50 psi below the selected LAND ALT.

Correct! Wrong!

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

True.

False.

Correct! Wrong!

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

FL180.

FL100.

FL250.

FL410.

Correct! Wrong!

What is the purpose of the recirculation fans?

To decrease the air conditioning system pack load.

To increase the pressure in the cabin.

To operate as air mixers in the mix manifold.

If increased smoke removal is required.

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.

True.

False.

Correct! Wrong!

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

Right engine strut.

The keel beam.

APU bleed duct.

Left aircond bay.

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 _____.

60 seconds.

5 seconds.

20 seconds.

3 minutes.

Correct! Wrong!

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

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

The isolation valve is always open

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

The isolation valve is always closed.

Correct! Wrong!

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

The pressurization controller is moved to ALTN.

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.

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

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

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

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

Correct! Wrong!

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

The amber BLEED TRIP OFF Lights illuminate.

All statements are correct.

The amber PACK TRIP OFF Lights illuminate.

The amber WING-BODY OVERHEAT Lights illuminate.

Correct! Wrong!

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

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

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

All three modes use DC motor.

All three modes use AC motor.

Correct! Wrong!

Where are the bleed trip sensors installed?

On the 9th Stage bleed air line.

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.

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!

Overheat detection is provided by temperature sensors located:

In the mix manifold.

Downstream of the packs and the mix manifold.

Downstream of the packs.

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

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 air-ground sensors.

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

Throttles position and signals from the IRS.

Throttle position from both stall management computers.

Correct! Wrong!

The maximum differential pressure is:

7.90 psi.

8.45 psi.

8.65 psi.

9.10 psi.

Correct! Wrong!

Water tank pressurisation in flight is normally provided by:

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

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

Bleed air from the APU.

Correct! Wrong!

The ram air system provides cooling air for the:

Heat exchangers.

Cargo area.

Packs

Cargo area and packs.

Correct! Wrong!

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

The FO's pitot static system.

The two pitot static systems.

The captain's pitot static system.

The ADIRUs.

Correct! Wrong!

In MANUAL pressurization mode the outflow is driven by?

A motor supplied from DC standby bus.

A motor supplied from DC bus 1.

Requires AC power from transfer bus 1.

A motor supplied from DC bus 2.

Correct! Wrong!

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

False.

True.

Correct! Wrong!

In cruise the air conditioning ram air doors are:

Modulate as a function of airspeed.

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

Fully closed.

Fully open.

Correct! Wrong!

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

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

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

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

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

Correct! Wrong!

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

Three.

Two.

One.

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

Correct! Wrong!

Where is the forward outflow valve located?

There is no forward outflow valve.

Forward of the left hand air conditioning inlet.

In the nose landing gear bay.

Forward of the right hand air conditioning inlet.

Correct! Wrong!

How are the Engine Bleed Air valves powered?

They are pneumatically activated and DC operated.

They are DC activated and pneumatically operated.

They are AC activated and pneumatically operated.

They are pneumatically activated and AC operated.

Correct! Wrong!

The recirculation fans:

Increase airflow at greater cabin differential pressures.

Provide overheat detection downstream of the packs.

Reduce air conditioning pack load.

Are driven by a DC motor.

Correct! Wrong!

Engine bleed air is obtained from:

5th and 8th stage of the compressor section.

5th and 9th stage of the compressor section.

4th and 8th stage of the compressor section.

4th and 9th stage of the compressor section.

Correct! Wrong!

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

Left and Right WING‐BODY OVERHEAT lights illuminated.

APU BLEED light illuminated on overhead panel

Left WING‐BODY OVERHEAT light illuminated

Right WING‐BODY OVERHEAT light illuminated.

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:

Close.

Open.

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 ON.

When the APU bleed valve is open.

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.

Correct! Wrong!

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

True.

False.

Correct! Wrong!

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

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

Nothing. This is normal condition before engine start.

Do not start the engines, check MEL.

Do not start the engines, call Maintenance.

Correct! Wrong!

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

When TD is reached.

When within 15 000 feet of the landing airport.

When retard is announced in the FMA.

When descending 0.25psi below the selected flight altitude.

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

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

Correct! Wrong!

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!

From where does the Cabin Auto Controller get its inputs.

From the Captain’s CDU.

From the static ports.

From the EFIS control panel.

From the ADIRUs.

Correct! Wrong!

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

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

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

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

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

Correct! Wrong!

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

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.

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

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

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

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

Correct! Wrong!

The DUAL BLEED light is illuminated. Engine thrust:

Should be limited to idle.

Should be limited to 40% N1.

Is unlimited. Dual bleed light is advisory only.

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.

True.

False.

Correct! Wrong!

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

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

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

True.

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

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!

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!

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.

10 000 ft and 41 000 ft.

8 000 ft and 41 000 ft.

7 500 ft and 41 000 ft.

12 000 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!

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.

True.

False.

Correct! Wrong!

Forward cargo compartment only.

The pneumatic duct pressure gauge:

Indicates pressure in left and right pneumatic ducts.

Is DC powered.

Indicates pressure available for engine anti-icing.

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 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.

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

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

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!

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

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

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

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

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

Correct! Wrong!

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

False.

True.

Correct! Wrong!

What are the causes of an amber AUTO FAIL light?

All statements are correct.

Loss of DC power or controller fault.

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

Outflow valve control fault or excessive differential pressure.

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.

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

Engine thrust is increased towards takeoff thrust.

When the PSEU is activated.

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:

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

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

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

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

Correct! Wrong!

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!

The motorized Exhaust valve:

Allows for increased ventilation in the smoke removal configuration.

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

All statements are correct.

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

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.

True.

False.

Correct! Wrong!

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

AIR COND.

OVERHEAD.

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

OVHT DET.

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.

Electrically by the air-ground safety sensor

Hydraulically when extended the main landing gear

Electrically in the air and pneumatically on ground

Correct! Wrong!

The isolation valve is:

AC operated.

AC controlled and pneumatically operated.

DC operated.

Correct! Wrong!

The altitude warning horn is:

A continuous warning horn accompanied by a Master Caution warning.

A continuous warning horn.

An intermittent warning horn.

An intermittent warning horn accompanied by a Master Caution warning.

Correct! Wrong!

The ram air system deflector doors:

Extend on the ground only.

Modulate between fully extended and retracted through the entire flight.

Are always extended when the gear is down.

Extend during slow flight when flaps are not retracted.

Correct! Wrong!

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

True.

False.

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 an overheat trip.

The fault was caused by a controller fault.

Correct! Wrong!

Boeing 737NG – Air Systems

Quiz

Boeing B737NG - Air Systems

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

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?

An illuminated BLEED TRIP OFF light indicates:

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

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

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?

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

What causes the amber PACK TRIP OFF Light to illuminate?

A DUCT OVERHEAT light only will cause:

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

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

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

During descent when the descent mode is activated:

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

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

What is the purpose of the recirculation fans?

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.

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

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

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

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 happens when the WING BODY OVHT TEST switch is pressed?

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

Where are the bleed trip sensors installed?

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.

Overheat detection is provided by temperature sensors located:

The maximum differential pressure is:

Water tank pressurisation in flight is normally provided by:

The ram air system provides cooling air for the:

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

In MANUAL pressurization mode the outflow is driven by?

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

In cruise the air conditioning ram air doors are:

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

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

Where is the forward outflow valve located?

How are the Engine Bleed Air valves powered?

The recirculation fans:

Engine bleed air is obtained from:

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

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:

When does the amber DUAL BLEED Light illuminate?

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

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

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

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

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?

From where does the Cabin Auto Controller get its inputs.

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

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

Where are the wing-body overheat sensors located?

The DUAL BLEED light is illuminated. Engine thrust:

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.

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

The 9th stage modulating and shut-off valve:

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.

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:

The pneumatic duct pressure gauge:

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.

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

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

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

What are the causes of an amber AUTO FAIL light?

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

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:

What systems need pneumatic power for operation?

The motorized Exhaust valve:

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

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

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:

The isolation valve is:

The altitude warning horn is:

The ram air system deflector doors:

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

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

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.

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.