Environmental Control System Flashcards
RAM AIR Ventilation is used only when:
When both packs have failed
The right-hand pack normally supplies:
Passenger cabin
Flight compartment exhaust air in flight is routed through the:
Under floor through the avionics bay to outflow valve at aft press bulkhead
Cabin air outflow is controlled automatically by:
The active CPC maintains aircraft pressurization
The pressurization system automatically pre-pressurizes the aircraft to:
-150 feet
Maximum negative differential pressure is:
-0.5 psi
If the cabin altitude reaches 14,000 feet the:
CPAM will trigger the oxygen system auto deploy to the passengers
On the ground, with Display Control Panel in “normal” what fan cools the cockpit displays?
GND fan/FLT ALT fan
When the press cont switch/light is pressed in:
It selects manual mode
The manual cabin altitude regulator, when selected UP:
Causes outflow valves to open and increase cabin altitude
The Manual (MAN) pressurization readouts are displayed on:
EICAS primary page
“Cabin pressure” aural warning will be heard when:
Cabin altitude is greater than 10,000 feet
The two safety valves located on the aft pressure bulkhead do what?
Provide overpressure and negative pressure relief
During ground operations the ground valve:
Is used to cool avionics and forward CRT’s and equipment
What is the normal source for engine supply bleed air to the manifold?
6th or 10th stage
Is the air in the lavatory and galley exhausted? If so, where does it go?
Yes, under the floor via dedicated exhaust systems.
How many smoke detector units are in each cargo bay?
3 frwd
2 aft
If smoke is detected by at least 2 of the 3 smoke detectors in a cargo bay, what happens?
The optional heater is shutdown and the intake and exhaust shutoff valves are closed.
Three uses for RAM air inlet?
1) heat exchanger for Air conditioning pack
2) heat exchanger for hydraulic systems 1/2
3) RAM air ventilation (cabin) if unpressurized.
How is bleed air conditioned?
First sent through a pre-cooler. If hot air is needed it will go to the cabin, if colder air is needed it will be cycled through the ACM until desired temperature.
How is Ram air used in relation to the PACKs?
It provides movement of air through the packs and helps cool down bleed air in the heat exchangers.
Left hand pack normally supplies conditioned air to?
Flight Deck
On the Air Conditioning panel, on the switch light that reads fault/off, What does the “fault” amber light mean?
A PACK has had an over pressure or over temp. That pack is shutoff.
What controls the pressurization? How many?
Cabin pressure controllers (CPC)
There are 2
What moves the outflow valve ?
Three independent motors. Two automatically by the CPCs and one is manual.
On the CABIN PRESSURE panel,
What does the amber “fault” mean on the FAULT/MAN switch-light?
The amber FAULT means that both CPCs have failed.
Where does recirculation air come from ?
Sucks air up from floor and moves it to the top vents.
How long will the px controller hold the take off field altitude ?
10 minutes. In case of air return
