Air Conditioning And Pressurization Flashcards
What controls the ram air regulating valve(RAVR)
The air conditioning system controllers
ACSC’s
ACSC
Air conditioning system controllers
In the event of dual pack failure what provides air
Ram air switchlight
Using the ram air switch light the air enters which supply system
The left supply system
How many avionic cooling fans
Fan 1 … Operates during flight or on the ground as alternate
Fan2… Operates on the ground or in flight as alternate
Standby fan operates as backup
When smoke is detected in the cargo bay
The heater power is removed and the shut off valves automatically close
How many Galley heaters do we have
Two 500 W heaters to supply heat to the galley and Service door area
Cabin pressure is maintained and controlled by
1 electro pneumatic outflow valves
If cabin altitude exceeds 14,000 feet
Passenger oxygen masks deploy
3-13
The outflow valves are automatically controlled by
Either of two independent Cabin pressure controllers
How many CPC’s
2
The pressure controller automatically switches on the ground when
On the ground for three minutes
The active CPC is displayed on the ECS synoptic page
EMER DEPRESS
Opens bothoutflow valves
14500 +-500
FASTEN SEATBELT SIGN
and
NO SMOKING SIGN
comes on automatically when
Cabin altitude is at or above 8500 feet
Px sign in auto
Do we have a CPAM
No
Amber fault light on one of the packs?
Failed in both auto and manual
Amber fault lt on the PRESS CONT Switch?
Both cabin pressure controllers have failed
When is pressurization data shown on the primary page
When in manual mode
What cools packs
Ram air
Ram air also provides cooling airflow to
Cooling of number one and two hydraulic system fluids
How many recirc fans
2
Test question
Low-pressure compressed air from a ground air conditioning cart can be supplied directly to
Into the flight and passenger compartment distribution systems
What are the two avionics exhaust fans used for
To extract the heated air from behind the flight compartment displays and from the avionics equipment
On the ground the heated air is dumped overboard through the ground outflow valve
Inflight the heated air is ducted to the pressurization outflow valve and dumped overboard
8-30-1 mes psm
OVBD COOL FAIL status?
“Overboard exhaust shutoff valve Has failed closed with the aircraft on the ground and the passenger door unlatched” QRH definition
- Ground valve fails to open after touchdown— SYS 3-24
OVBD COOL caution
Over board exhaust shutoff valve is not closed with the passenger door and service door closed
Aircraft will not pressurize
How many electrically controlled outflow valves regulate the cabin pressure
One!! This is a correction to a previous card
How many safety valves
Two…
One for overpressure relief
failedOne for negative pressure relief
Cabin altitude exceeds 14,000 feet
O2 masks deploy
14000 +-300
CABIN ALT WARNING
cabin altitude is greater than 10,000 feet
DIFF PRESS WARNING
differential pressure greater than 8.6 PSI
CABIN ALT caution
Cabin altitude is greater than 8500 feet but not greater than 10,000 feet
OVBD COOL caution?
Ground valve failed open with passenger and service door closed
What is the cabin altitude limitation regarding the pressurization system
The outflow valves will close to prevent The cabin from increasing above 14,500 +-500
Pressurization is controlled by
A single electric controlled outflow valve
ACSC stands for
Air conditioning system controller
2 ACSC’s
#1 ... Left HPV. LCV ISOL #2....right HPV
2 channels/controller
1 active /1standby
No EICAS indication for activechnnel
ACSC PROVIDES ?
Ice protection 4 packs
Auto shutdown
2 flowrates
PRSOV fail safe?
Closed
How many pressurization valves
1
Completely electric
What happens if both CPC’s fail?
Outflow valves go to a barometric hold
Recirc fan off at what temp?
OFF if “cabin” temp is greater then 30 degrees