Term
| What does the equipment cooling system do when the lower forward cargo fire switch is armed? |
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Definition
The forward cooling and ventilation system goes into override mode:
The vent valve remains closed
The rest is the same as the lower aft:
The supply fans are shutdown
shuts lower forward cargo heat valve
override valve opens to vent pressurized air overboard to draw air from the flight deck for equipment cooling
There is sufficient cooling at cruise and high differential pressures, but lower altitudes and lower differential pressures cause airflow to decrease
(FCOM Vol 2, Rev 2: 2.20.7) |
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Term
| What do we need to be aware of when the equipment cooling is operating in the override mode and we are at low altitude and high ambient temperatures? |
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Definition
During descent, the airflow decreases as the cabin pressure differential decreases.
* Note: Possible equipment failure from overheat due to low air flow.
(FCOM Vol 2, Rev 2: 2.20.7)
(QRH Rev 17: 2.18) |
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Term
| What is an easy way to eliminate unwanted galley odors quickly? |
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Definition
This happens automatically by design because the air is drawn out from the galley
(FCOM Vol 2, Rev 2: 2.20.8) |
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Term
| What causes a pack to enter the standby cooling mode? |
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Definition
Certain internal malfunctions can cause this.
If one pack is in standby cooling and the other is operating normally, the pack in standby cooling mode shuts down at lower altitudes and higher temperatures when standby cooling is not possible.
It will restart automatically when conditions permit.
If both packs are in standby cooling mode, or one is inoperative and the other is in standby cooling mode, the pack(s) will continue to run to maintain pressurization.
(FCOM Vol 2, Rev 2: 2.20.2) |
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Term
| What is the EICAS message for a pack in standby cooling mode and what is usually the cause? |
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Definition
PACK MODE L, R,
[the air cycle machine has failed;
It only has heat exchangers operating so no cooling on the ground or at low altitudes.]
Internal malfunctions
(FCOM Vol 2, Rev 2: 2.20.2 & 2.50.3)
[reference needed for bracketed item] |
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Term
| What does the trim air do? |
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Definition
It is hot air which is added to the conditioned air to control the temperature in each zone.
(FCOM Vol 2, Rev 2: 2.20.3) |
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Term
| Can cabin zone temperature be maintained with the loss of trim air? |
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Definition
Yes.
Cabin temperature controllers attempt to maintain all zones at the average target temperature.
(FCOM Vol 2, Rev 2: 2.20.3) |
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Term
What is the purpose of the bleed isolation valve?
What can make the bleed isolation valve show closed? |
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Definition
(Purpose stated here)
Shows Amber Closed if:
A bleed loss
Duct leak failed/closed valve
The switch is off
They work automatically to isolate a leak.
The detection process is automatic.
(FCOM Vol 2, Rev 2: 2.10.7 & 2.40.2-3) |
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Term
| What causes the APU bleed valve to open automatically? |
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Definition
It is armed to open whenever the APU is running and the altitude is (????) bleed logic
(FCOM Vol 2, Rev 2: 2.10.7, 2.40.1, & 7.30.1) |
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Term
| What do you see on the EICAS when an outflow valve is selected to manual? |
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Definition
Outflow position is displayed on the EICAS display
(FCOM Vol 2, Rev 2: 2.30.2-3) |
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Term
| How can you manually control the pressurization? |
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Definition
If one outflow valve is not operating automatically, close it to allow the system to operate nomrally with the other valve.
To manually operate the valves:
Set the OUTFLOW VALVE switches to MAN.
Hold the OUTFLOW VALVE MANUAL switch OPEN or CLOSED to adjust.
(FCOM Vol 2, Rev 2: 2.30.2-3)
(QRH Rev 17: 2.20) |
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