Environmental Control System Ch. 12 Flashcards
Where does the ECS get its bleed air from?
Engine or APU
Where is the bled air fed for the ECS?
To the PACK (Pressurization and Air Conditioning Kit)
What 3 systems work together to ensure proper air quality and quantity to the cabin?
Pneumatic, ECS, and Pressurization
What are the 3 functions of the ECS?
Airflow control
Cabin/Cockpit Temperature
Equipment cooling
What does the Air Management System Controller (AMSC) do?
Provides information for display into the data concentrator unit for fall messages, and alerts on the EICAS
What are the three main groups of the AMSC?
BAS, WAI, and ECS
What is the purpose of the Air Cycle Machine?
Receives bleed air that requires cooling, cleaning, & then reheating of that air to be distributed to the cabin and the cockpit.
Temp at the plenum is 35F - controlled by adding hot air from refrigeration unit inlet
What are the air cycle machine (ACM) components?
Pack inlet valve - pressure regulator for the ACM. Modulated by the AMSC - Normal or High modes - Switch is on the overhead panel.
Ozone converter - Catalytic converter. Cleans the air from the engines and reduces the ozone level in that air. Ozone levels contribute to “jet lag” or “air sickness.” Cleaned air is sent to the ACM.
Primary heat exchanger - reduces bleed air temperature. Cooled by ram air
Compressor - increases the air pressure
Secondary heat exchanger - Air cooled by ram air. Enters a duct to be entered into the reheater.
Condenser - Bleed air goes through the hot side, increasing water vapor. Subfreezing air on the cooled side acts as a heat sink for condensation. Internal bypass to prevent blockage of cold side inlet face from ice.
Water separator - removes 80% of the condensed water.
Water separator spray nozzle
TIT control - controls turbine inlet to 75F to protect the ACM from failures due to turbine icing.
Re-heater - condenses the water further and removes it.
Cooling Turbine - Allows cooled air to pass over the condenser to reduce the condenser temperature and then air flows into plenum for distribution.
Plenum - limited to 35F. Distributes air through the Gasper (eyeball) vents. When less than 35F sensed at plenum, the AMSC adds hot bleed air to maintain 35F in the plenum.
In the event of a failure or malfunction of the normal cabin ACM supplied air, an alternate cabin air source is available. What is that air source & where does it come from?
Right side manifold downstream of the pre cooler.
How is the nose avionics bay cooled?
There is an air inlet & outlet. Air is circulated via cooling fans
