Pressurisation Flashcards
What does the digital controller control?
The electropneumatic outflow valve AND the pneumatic valve (slaved)
What conditon must exist for the digital controller to work?
manual control lever must be in the fully down and anticlockwise postion i.e OFF
What does the manual controller control?
The pneumatic valve only. Epnue valve is commanded closed
How many recirc and gasper fans are there?
2 recirc
1 gasper
The CPCS contains 2 subsystems. What are they and what do each consist of?
One digital electropneumatic subsystem(automatic mode).- One pneumatic subsystem (manual mode).Both subsystems comprise a digital controller, a manual controller, anelectropneumatic outflow valve, a pneumatic outflow valve, an air filter,two pressure regulator valves, an ejector pump, two static ports, and aCabin Pressure Acquisition Module (CPAM).
When is positive and negative pressure relief provided by the outflow valves? In auto mode what is the cabin alt limitation?
8.2 psi maximum.
0.3 psi.
15000 ft maximum.
What is the max differential pressure and how is the theoretical cabin altitude reached?
7.8 psi
reached at the lowest possible airplanealtitude considering a minimum cabin altitude rate of climb and amaximum airplane rate of climb.
What does the take-off sequence do and how long does it last?
Descends cabin to 0.2psi below T/O altitude until cabin alt becomes greater than actual altitude or 15 mins has elapsed
How does the flight sequence operate?
Controller schedules cabin alt of greatest value between the theoretical cabin altitude and the selected landing altitude minus 11 mbar (300 ft at SL).
Climb limited to 600fpm
Descent limited to 450fpm
What happens on landing?
Cabin is 300ft below landing altitude to prevent cabin bump then climbs at 650fpm when engine 1 thrust lever is at idle
