PRESSURIZATION Flashcards
How many outflow valve are there?
2
One FWD and one AFT
How is cabin air normally discharged?
20% via the FWD valve and 80% via the AFT valve
How is excessive differential pressure protection achived?
Via 2 positive pressure relief valves and
via 4 negative pressure relief valves
What data entry allows for fully automatic pressure control?
Data input into the FMC
For T/O, is the aircraft pressurized or depressurized?
A small pressurization prior to rotation is supplied to achieve a smooth cabin altitude transition to the cabin altitude climb schedule
Without accurate FMC Cruise altitude data, what is the assumed cabin altitude?
39’000 ft
At 43’100 ft, what would the cabin altitude be?
8’000 ft
Does the Aircraft land pressurized or de-pressurized?
Cabin altitude decreases to slightly below the FMC planned landing altitude to ensure a small positive pressurization at touchdown.
Where does the landing altitude barometric pressure correction come from?
The captains altimeter setting
What two manual operations will provide pressurization data on the EICAS?
Setting either outflow valve switches to manual or pulling the LDG ALT selector
After a loss of cabin pressurization, what event will cause the outflow valves to re-open?
The airplane reaching 15’000 ft or descending below cabin altitude
What is the max differential?
9,4 PSI
What is the target altitude for the cabin during a descent?
190 ft below field elevation to land slightly pressurized for structural reasons
Which landing altitude does the ASCPCs use for calculations?
Landing altitude depends on distance from the departure airport.
If the distance is less than 400nm or less than halfway along the route, the ASCPC uses the departure airports landing altitude
Does a return to the departure airport require any interaction to set landing altitude for the pressurizatio`?
No, unless you are more than 400nm away for more than halfway away
