Flashcards in Environmental Control System Deck (21):
What are the three systems that make up the ECS?
FACS - Forward Avionics Cooling system
HVS, Heating and Ventilation System
RBCS - Rear Bay Cooling System.
What is the purpose of the heating control unit in the HVS system?
It is the central processing unit and maintains the desired air temperature between ambient and 65 degees C
Where is the temperature control valve?
What is the purpose of the temperature control valve?
Controls the flow of P3 air.
Where is the Pressure Regulating and Shut Off Valve? (PRSOV)
Left engine bay.
What is the purpose of the PRSOV?
1) Removes pressure variations and surges associated with engine performance.
2)Acts as an On/Off Valve.
If the HVS fan were to overheat and latch off, once it had cooled how would you turn the HVS back on?
Power must be re-cycled to re-initiate the system.
Where is the overheat Temperature sensor for the HVS?
Immediately downstream of the mixing unit.
What is the purpose of the overheat temperature sensor?
Detects over heat (90 degrees C) and provides [HVS DUCT HOT] caution.
What is the purpose of the ambient temperature sensor in the HVS system? (furthest sensor downsteam)
It monitors the duct temperature with respect to the selected setting and provides a feedback signal to the heating control system.
Which is the primary fan in the FACS system?
What is the fan inlet duct designed to do?
Slow the airflow so that water a particles can drop out of the airflow.
If the FACS system had a failure detected by an underspeed sensor what caption would be displayed?
[FACS PRI FAN] or [FACS SEC FAN]
What are the available positions on the primary and secondary fan switches? (FACS)
Primary - Auto and Off
Secondary - Auto, Manual and Off
What are the available positions on the RBCS fan switch?
OFF, 1 and 2
Where is the air inlet for the FACS?
Right hand nose bay.
Why are there 2 fans for the RBCS?
Where is the Heating control unit located?
Forward bulkhead of the rear bay.
What stops the HVS from over pressurising if everyone closes their vents?
2 vents underneath the Pilots an co-pilots seats are permanently open.
Where are the switches for the FACS?