Pressurization Flashcards
Can maintain a cabin altitude of
7500 ft at 41000 at 8.55 psi
What does the cabin controller do
Ensures outflow safety valves maintain the selected cabin altitude and makes sure the cabin pressure changes at an acceptable rate.
Outflow safety valves
They allow the discharge of cabin air. Located in the rear pressure bulkhead
Pneumatic relays
Two of them sense pressure changes within controller and sends the information to the outflow safety valves.
Venturi
In the forward luggage Bay Area extracts air from the cabin controller.
In manual operation, it extracts air from one outflow safety valve via manual pressurization controller.
Air jet jump
On the rear pressure bulkhead.
Extracts air from the outflow safety valves.
Operated by bleed air, ensures desired differential pressure.
Pressure regulators
Two of them function as safety devices. On the rear pressure bulkhead, shut both outflow safety valves in cabin reaches 13,500 +~ 1500 ft.
Fan operated Venturi
Rear pressure bulkhead. Controlled by PRESSN switch. When in auto, and on the ground the fan operates if an engine or APU is running thus allowing for the aircraft to not be pressurized.
With weight off wheels, the fan stops thus allowing it to be pressurized.
With the switch in OVRD and on the ground. The aircraft can be pressurized.
Cabin altitude warning goes off when
When cabin alt reaches 9300 +- 300 ft.
Cabin high datum selection goes off when.
It’s used at airfields greater than 9000 feet. Horn goes off at 14000
Electrical sources
PE:
Cabin alt warning
Ram air control valve
PS2:
Recirculating fan control
Flood flow valve actuator
XS2:
Fan operated Venturi
