Enviornmental Control System Flashcards
What does the ECS do on a basic level?
Takes engine bleed air, cools it, and delivers it to the cabin for ventilation and pressurization.
Anytime the starter is activated the ECS will?
Automatically shut down.
What automatically selects either P2.5 or P3 air?
High Pressure Shutoff Valve
When does the system use P3 vs. P2.5?
More than 80% NG uses P2.5.
Less than 80% NG uses 3.0.
How many ports do 2.5 vs. 3.0 air have?
Single port for 2.5
Dual ports for 3.0
What does the TCV valve do?
Valve controls how much air enters the heat exchanger and how much bypasses it.
If temperature is less than desired what does the TCV do?
Bypass more air past the heat exchanger.
If temperature is higher than desired what does the TCV do?
Duct more air into the heat exchanger.
How is the TCV controlled in AUTO mode?
By signals sent from the cabin temperature sensor located in the cabin headliner.
How is the TCV controlled in MANUAL mode?
Directly controlled by the guarded temperature switch.
How is air that enters the heat exchanger cooled?
Ambient NACA air is drawn into the Heat Exchanger and water is injected to assist in cooling.
After air leaves the heat exchanger where does it go??
The Cooling Turbine and is then joined with air that bypassed the heat exchanger.
After air passes the Cooling Turbine where does it go?
The Water Separator to remove any moisture before entering the cabin.
Normal GROUND operation, pressurization switch in AUTO, condition lever in GND IDLE, and electrical power supplied to the system what position is the solenoid valve in?
OPEN and the airplane will be unpressurized.
When the condition lever is moved to FLT IDLE just prior to takeoff what happens to the solenoid valve?
Electrical power is removed and the valve closes.
What is provided for ECS Overheat/Overpressure Protection?
Two over temp switches.
One over pressure switch.
What happens in the ECS is any of the two over temp switches or one over pressure switch are activated?
The Primary Shut-Off Valve will close.
Amber CAWS ECS will be annunciated.
What does the supplemental heating system consist of?
Where are they?
Two 28 VDC heating units.
- U/F (under floor heater) under the cabin floor near the cockpit.
- Cabin Heater under the cabin floor near the cargo bay area.
What do the two Heating Units consist of?
A fan motor.
Heating element.
Thermal protection switch.
What provides the RECIRC air?
Two blower assemblies located at the rear of the cabin.
How is power controlled for both the compressor and evaporator fans?
(OHP)
On the overhead panel, under COOLING, selecting the SYS switch to ON or OFF.
On the overhead panel under COOLING there is a switch for RECIRC or COOL, what does this do?
RECIRC supplies power to the evaporator fans only.
COOL supplies power to the fans and compressor.
