Air Systems Flashcards
What prevents debris from entering the CACs during normal ground operations and landings?
Deflector Doors
How many CACs operate when the APU is the only power source?
2: One on each side
What should be done to restore PACK operation when a PACK shuts down automatically?
Press the AIR CONDITIONING RESET switch.
A PACK operating in the Standby Cooling mode at low altitudes and high outside air temperature will:
Shut down
What provides cabin and flight deck ventilation if both packs are inoperative
The Alternate Ventilation System
What provides ventilation and conditioned air to the forward Cargo compartment?
Forward E/E cooling exhaust, a dedicated refrigeration unit, an inline electric heater and a forward cargo exhaust fan.
How can Bulk Cargo Heat be restored when automatic overheat shutdown occurs in flight?
It cannot be restored in flight.
What is the default altitude if cruise altitude is not available from the FMC and pressurization system operating in the automatic mode?
43,000
What protects the airplane fuselage from the excessive pressure differential?
Positive and negative pressure relief valves and vents
Where does hot bless air flow when the ENGINE ANTI-ICE selector is set to ON?
The engine core and inlet cowl
What cools the Large Motor Power Distribution System in the aft E/E compartment?
The Power Electronics Cooling system. PECS
In Cruise flight, and the pressurization in AUTO, what is the maximum cabin altitude?
No more than 6,000 feet.
What is the Integrated Cooling System? ICS
A centralized refrigeration system that provides cooling to galley carts and recirculated cabin air.
What happens to cabin altitude during unplanned level segments?
Cabin altitude remains constant as long as the airplane altitude is not changing.
In cruise, when the Humidification HUMID switch is in the on position, what happens?
The Flight Deck Humidification system operates automatically.
Where is the liquid cooling system PECS quantity displayed?
On the STATUS page.
What does “RF” indicate when displayed on the STATUS page?
The PECS system reservoir servicing is recommended.
Where is the cargo compartment temperature displayed?
On the AIR synoptic page.
Is it ever normal for the cabin altitude to descend while the airplane is climbing?
Yes, after takeoff from an airport with a field elevation above 8000 feet
What do the Cabin Air Compressors do during initial engine start?
All CACs are commanded off.
Which cargo compartment(s) can carry live animals?
Bulk and Forward Cargo compartments
The passenger compartment de-humidifier system operates….
Automatically when electrical power is available.
Why is the flight deck pressure higher than the cabin pressure?
To prevent smoke from entering the flight deck.
