Air Systems Flashcards
When is the avionics cooling switch operative
Fan Mode
OVRD Mode
Inflight only and is used to control radio rack cooling
Fan- Primary fan cools the radios if the primary fan fails, the backup fan comes on automatically
OVRD- The radio rack fans are off, the venturi valve is commanded open and venturl airflow cools the radios
What happens to the Avionics Cooling fan on the ground
Both fans stay on all the time and the venturi valve is closed
RAM Air Switch
OFF
ON
OFF- Ram Air Valve commanded closed
ON- Ram Air Valve Commanded open, allowing ram air to enter the air conditioning ducts
Ram in inflight
Provides ventilation for the cabin/cockpit when air conditioning is not available
Can you use the RAM Air on position on the ground?
No
AC Pack Shutdown Switch
AUTO
OVRD
Auto- Allows Automatic Pack shutdown in the event of a engine failure
OVRD- Overides the auto pack shutdown in the event of a engine failure or when the packs are shut off on the FMC.
When is the auto AC pack shutdown feature disarmed
Above 3000 AGL
When will both AC packs automatically shut down
If either engine fails during takeoff or if selected off in the FMS
What happens to AC Pack if a high supply duct temp is sensed
Pack shutsdown automatically and cannot be overridden
Flow Switch Positions
NORM
High
NORM- The flow control valve solenoide is energized to provide a lower airlow rate
HIGH- The flow contol valve solenoid is de-energized to provide a higher airflow rate
What postion must the flow switch be in for takeoff
NORM
ISOL Switch Position
CLSD
OPEN
AUTO
CLSD - Isolation valve is commanded closed, Isolating the left and right pneumatic systems
OPEN- Isolation valve is commanded open, allowing crossfeed of left and right pneumatic system
AUTO- Automatically controled by pneumatic system controller. Allows Auto crossfeed of left and right pneumatic system during one bleed source operation with ice protection on.
Where is Cabin Altitude and Cabin Rate displayed
AIR SD and Secondary Engine SD
Instrument Panel Flow Indicator
ON
OFF
On- on the ground, with AC off, indicates intrument panel cooling fan airflow
OFF- on the ground, with AC off, indicates the absence of airflow and cooling fan failure
Gasper Fan Switch
ON
OFF
ON- Provides Supplemental Airplane Ventilation with or without air conditioning packs operating.
OFF- Booster fan is not on, switch is extinguished
Cabin Press control panel button illuimination
Select
Manual
Select- Illuminates to indicate failure of both automatic cabin pressure controllers.
Manual- When pushed, MANUAL illuminates and the cabin pressurization system operates in manual mode. Also Used to alternate control between cabin pressure controllers (Auto 1 and Auto 2).
How to turn the packs on/off in the FMC - Takeoff with Air Conditioning Packs off (2)
TO/APPR key……………………..Push
PACKS……………………………….Line select ON to OFF
Observe PACKS ALL OFF alert message on EAD
What happens when AC Packs switches are in AUTO?
Both packs will automatically shutdown in the event of a engine failure.
AIR DATA Heat Pushbutton
OFF
OFF- (amber light) all air data system heaters are off
The light is dark when all heater circuits are on for pitots, rudder limiter, stall probes, static ports, and RAT probes are energized.
RAT probe heat on the ground is……
Inhibited
WING ICE DET Switch
RESET
TEST
RESET- resets system and removes WING ICE DETECTED alert from the EAD. System will not reset if ice is detected.
TEST- test the wing ice detection system
When does the wing ice detection system function
On the ground only and alerts the pilots to the pressence of wing upper surface ice. Inhibited during takeoff, landing and inflight
Can you takeoff with WING ICE DETECTED alert displayed
NO
Which cockpit windows are electrically heated and/or anti fogged
Three Pilot windshields are electrically anti-iced and electrically anti-fogged
The Clear view windows are anti-fogged
Which controll surfaces are anti-iced with engine bleed air
Wing, Slats and horizontal stab leading edge
Which engine controls anti-iced system
Either or both engines
Which engine conponents are anti-iced
Engine nose cowl and provides ground and inflight anti-ice heat.
Engine anti-ice is independent of airfoil systems.
WINDSHIELD ANTI-FOG Switch
OFF
ON
OFF- Turns off windshield and clearview anti-fog
ON- Turns on windshield and clearview anti-fog
When is WINDSHIELD ANTI-FOG Switch available
During ground and flight operations
WINDSHEILD ANTI-ICE Switch
OFF
ON
OFF- Turns off windshield anti-ice
ON- Turns on windshield anti-ice
When is WINDSHEILD ANTI-ICE Available
During ground and flight operations
What altitude is the auto pack shutdown feature disarmed….
3000 ft AGL
