Environmemtal - Pressurization Flashcards
What temp do the pre coolers, cool the bleed air to?
500 degrees F
What is bleed air used for?
Wing anti ice Engine anti ice Pressurization of the cabin Windshield anti ice Service air (23 psi)
When does the door seal annunciator light illuminate?
When pressure drops below 8.45 psi
When are LH or RH source selectors of bleed air used?
In the case of over pressurization
What does the fresh air setting do?
Closes all the valve and only allowing Ram air in.
Only to be used on the ground, as it will not pressurize the aircraft.
EMER PRESS ON annunciation
Emergency pressurization is connected to windshield anti ice and uses windshield anti ice air.
Opens both windshield anti ice and Emergency pressurization control valves supply 6ppm, 120 degree air into the cabin.
When does the BLD AIR O’HEAT annunciator illuminate?
Temps greater than 540 degrees
How can the temperature be controlled?
Automatically or manually
How does the temp control system function?
By changing the position of the cabin bleed air heat exchanger, ram air modulating valve.
What does the ram air modulating valve do?
Controls the amount of ram air cooling that passes through the cabin heat exchanger.
When will the air conditioning compressor operate?
When the ram air modulating valve is full open and the compressor switch is in auto
When does the air conditioning compressor kick off?
When the ram air modulating valve is 70% or more closed.
When does the AIR DUCT O’HEAT annunciator illuminate
When cabin supply air temp exceeds 300 degrees
MASTER CAUTION is also associated.
Select a cooler temp.
When will the air compressor automatically kick off?
Generator failure
How many evaporators on the aircraft
2
One in the FWD cabin under side facing seat
One in the AFT bulkhead
How is the radio stack cooled?
Two cooling fans.
Fan 1 is located within the radio stack.
Fan 2 is located in the cockpit below the right floor panel
Both come on automatically
Maximum cabin differential
8.6 psi d
Emergency pressurized air comes from where?
EMER switch, which pulls air from windshield bleed air
Where does incoming air for pressurization come from?
Source selector
BOTH, LH, or RH
How many valves for the outgoing air?
2 outflow valves on aft pressure bulkhead
What is the digital pressure controller set to maintain at maximum?
8.3 psi d
Max rates of climb/decent for the cabin?
Climb - 500 fpm
Decent - 600 fpm
When do both outflow valves open?
When on the ground because of the squat switch
What do the maximum differential pressure relief valves do?
They compare cabin pressure, to outside static air pressure.
Can the Emergency dump valve be operated with no DC power?
No
Cabin differential pressure shows what?
Cabin altitude and differential pressure
When does the system begin auto schedule mode?
When either squat switch indicates in flight, or the aircraft altitude increases 1,500 ft
Position of the outflow valves in ground taxi mode
Both outflow valves are fully open
Pre pressurization mode
On the ground with both throttles about 85% N2, both outflow valves slowly close
What happens if the yellow caution light appears on top left corner of controller display face?
Controller has switched from AUTO to ISOBARIC mode
