Air Conditioning Flashcards
Each air conditioning pack is supplied pressurized and flow-regulated air by…
- engine or APU bleed.
- a Ram Air Turbine (RAT).
- cabin air compressors (CACs).
- APU bleed.
cabin air compressors (CACs).
Outside air is supplied to four electric cabin air compressors (CAC) through two dedicated inlets located in the wing to body fairings. The air is then pressurized and flow-regulated by the CACs and supplied to _____ air conditioning pack(s).
- two identical
- three identical
- four identical
- one
two identical
Normally, to maximize system efficiency, how many cabin air compressors (CACs) run when using the APU as the power source?
- One on the left side.
- Two on the right side.
- One on each side.
- All four.
One on each side.
A ground source of conditioned air may be used to supply conditioned air directly to the cabin distribution system, eliminating the need for pack operation.
- True
- False
True
If an overheat or significant pack fault is detected, the pack…
- switches to standby mode.
- continues to run until it is manually shut down.
- switches to alternate cooling.
- shuts down automatically.
shuts down automatically.
Cabin attendants can reduce outside airflow to the cabin based on…
- the number of airplane occupants.
- inside air temperature.
- outside air temperature.
- selecting the TRIM AIR on the flight deck air conditioning panel.
the number of airplane occupants.
Pack outlet temperature is controlled by the…
- temperature zone requiring the warmest air.
- trim air valve.
- temperature zone requiring the coolest air.
- pack valve controller.
temperature zone requiring the coolest air.
What is the status of CACs and Packs during a normal engine start?
- One CAC operates on each side. Both packs are commanded off.
- Both CACs operate on each side. Both packs are commanded off.
- All CACs are commanded off during the initial start sequence.
- All four CACs and both packs are fully operative during normal engine start.
All CACs are commanded off during the initial start sequence.
Which of the following occurs during Standby Cooling Mode?
- EICAS advisory message PACK MODE (L, R) is displayed.
- STBY COOLING is displayed in amber on AIR synoptic.
- Pack cooling capacity may be less than in normal mode.
- All of the above are correct.
All of the above are correct.
Which of the following statements is correct when the right pack is operating in the standby cooling mode (left pack operating normally)?
- The right pack automatically switches to high flow.
- The right pack may shut down at higher altitudes.
- The right pack cooling capacity may be less than in normal mode.
- There is no EICAS indication of either pack operating in the standby mode.
The right pack cooling capacity may be less than in normal mode.
A/An ________ source of conditioned air may be used to supply air directly to the cabin distribution system.
- APU bleed
- ground
- engine bleed
- standby
ground
What cools the large motor power distribution system located in the aft E/E equipment compartment?
- The Integrated Cooling System (ICS).
- The Power Electronics Cooling System (PECS)
- Conditioned air ducted from the passenger cabin.
- The Miscellaneous Cooling System.
The Power Electronics Cooling System (PECS)
The Power Electronics Cooling System (PECS) is a liquid cooling system used to cool the large motor power distribution system. The large motor power distribution system is located in…
- the Flight Deck equipment compartment.
- the foward E/E equipment compartment.
- the wing to body fairings.
- the aft E/E equipment compartment.
the aft E/E equipment compartment.
Choose the correct statement below regarding the Integrated Cooling System (ICS).
- ICS is a refrigerant cooling system designed to reduce heat loads on the flight deck and integrated with the forward electrical and electronic compartment cooling.
- ICS is controlled by a single ICS switch on the overhead panel that can remove system power.
- ICS is a centralized refrigeration system that provides cooling to galley carts and recirculated cabin air.
- ICS provides cooling and heat dissipation for components in the aft electrical and electronic compartment and non-essential equipment in the lower lobe area.
ICS is a centralized refrigeration system that provides cooling to galley carts and recirculated cabin air.
Identify which statement about the operation of the pressurization system description is true.
- In operation with the loss of pressurization, it is important that the flight crew close the outflow valves during descent.
- In the cruise mode, maximum cabin altitude is no more than 6000 feet.
- Two seconds after touchdown, both outflow valves open to pressurize the cabin.
- If cruise altitude is unavailable from the FMC in AUTO, the default cruise altitude is 41,000 feet.
In the cruise mode, maximum cabin altitude is no more than 6000 feet.
Which statement is correct regarding engine bleed air?
- It is only used for cabin pressure.
- It is only used for engine core and inlet cowl anti-ice.
- It is only used for wing anti-ice.
- It is only used for hydraulic reservoir pressurization.
It is only used for engine core and inlet cowl anti-ice.
On the787-9, the ALTN position of the VENTILATION switch…
- positions the FWD and AFT outflow valves toward the ten and one o’’'’clock positions respectively.
- puts both PACKS in a low flow condition until the system can be reset on the ground.
- commands all recirculation fans to operate at a higher flow rate to increase air flow.
- opens a valve allowing fresh outside air to be drawn into the air distribution system.
positions the FWD and AFT outflow valves toward the ten and one o’’'’clock positions respectively.
What controls the pack outlet temperature?
- The master cabin temperature controller.
- The temperature zone requiring the coolest temperature.
- The temperature zone requiring the warmest temperature.
- The average demand of all temperature zones.
The temperature zone requiring the coolest temperature.
Which statement about the Alternate Ventilation System is correct?
- The Alternate Ventilation System provides air flow into the forward electronics bay when both air conditioning packs are off on the ground.
- When the airplane is not pressurized normally and the ALT VENT switch is ON, air is drawn from the foward outflow valve to the flight deck.
- The ALT VENT switch is guarded to prevent selection, which could open the vent valve and depressurize the plane.
- The Alternate Ventilation System provides an alternate means of ventilating the cabin and flight deck in the event both packs are inoperative.
The Alternate Ventilation System provides an alternate means of ventilating the cabin and flight deck in the event both packs are inoperative.
The aft equipment cooling system provides cooling and ventilating air for the aft E/E equipment compartment and heating/ventilating air for the aft cargo compartment.
- True
- False
True
The aircraft is divided into how many temperature zones for air conditioning?
- 5
- 6
- 4
- 7
7
Two identical air conditioning packs are supplied pressurized air from…
- four Ram Air Fans.
- the APU bleed air.
- four CACs.
- the engine bleed air system.
four CACs.
If one Cabin Air Compressor (CACs) fails its respective air conditioning pack will shut down.
- True
- False
False
Normally, to maximize system efficiency, only one CAC on each side runs when using __________ as the power source.
- the APU
- PCA
- external air
- the right engine
the APU
For normal engine starts, how many Cabin Air Compressors (CACs) are commanded off during the initial start sequence?
- one on the right side and one on the left.
- one on the right side
- one on the left side
- all four
all four
For certain internal malfunctions, pack control automatically uses ___________ as a backup to normal mode.
- alternate cooling mode
- secondary cooling mode
- standby cooling mode
- direct cooling mode
standby cooling mode
If one pack is in standby cooling mode and the other pack is operating normally, the pack in standby cooling will shut down at lower altitudes and…
- lower outside air temperatures.
- higher outside air temperatures.
- higher humidity conditions.
- lower humidity conditions.
higher outside air temperatures.
The flight deck receives _________ conditioned outside air and the passenger cabin receives a mix of outside air and recirculated air.
- 100%
- 90%
- 75%
- 50%
100%
A passenger compartment dehumidification system operates automatically when…
- the upper RECIRC FAN is ON.
- both RECIRC FANs are on.
- FWD EQUIP COOLING is ON.
- electrical power is available.
electrical power is available.
Turning the recirculation fans off…
- results in increased airflow.
- will increase the amount of fresh air to the passenger cabin.
- results in a decreased airflow to the passenger cabin.
- will result in an overheat condition in the passenger cabin.
results in a decreased airflow to the passenger cabin.
Recirculation fans must remain ON during hot weather operations unless a non-normal checklist directs to select them off.
- True
- False
True
On both the 787-8 and 787-9, the Alternate Ventilation System (AVS) provides an alternate means of ventilating the cabin and flight deck in the event both packs are inoperative.
- True
- False
True
Flight crew foot heaters are available…
- on the ground and in-flight.
- only with electrical power supplied by both engines.
- only with the APU providing electrical power.
- in-flight only.
on the ground and in-flight.
The humidification system operates automatically during cruise when the HUMID switch is on and is automatically switched off approximately 1-1.5 hours prior to touch down.
- True
- False
True
The aft cargo compartment is heated but the compartment temperature is uncontrolled.
- True
- False
True