Air Systems Flashcards
Describe the function of the Temperature Selectors.
AUTO
OFF
AUTO - provides automatic temp control for the associated zones. Rotating the control toward C (cool) or W (warm) manually sets the desired temp.
OFF - closes the associated trim air modulating valve.
Explain the meaning of an illuminated BLEED TRIP OFF light.
Excessive bleed air temp or pressure.
- related engine bleed air valve closes automatically - requires reset
Explain the function of the ISOLATION VALVE switch.
CLOSE
AUTO
OPEN
CLOSE - closes the isolation valve.
AUTO - isolation valve closes automatically if both engine BLEED air switches are ON and both air conditioning PACK switches are AUTO or HIGH.
- isolation valve opens automatically if either engine BLEED air or air conditioning PACK switch is positioned OFF.
OPEN - open isolation valve.
Explain the function of the TRIP RESET switch.
Push (if fault condition is corrected)
- resets BLEED TRIP OFF, PACK, and ZONE TEMP lights.
- related engine bleed valve opens, or related pack valve opens.
- lights remain illuminated until reset.
Describe the associated alerting with an E & E bay over temperature on the ground.
If an over temperature occurs on the ground, alerting is provided through the crew call horn in the nose wheel well.
Explain the function of the Pressurization Mode Selector
AUTO
ALTN
MAN
AUTO – pressurization system controlled automatically.
ALTN – pressurization system controlled automatically using ALTN controller.
MAN – pressurization system controlled manually by outflow valve switch, both auto controllers bypassed.
Recall what cabin altitude will cause the cabin altitude warning horn to sound.
-Intermittent Cabin Altitude Warning Horn sounds when cabin reaches 10,000 feet altitude.
Explain the function of the cabin ALT HORN CUTOUT Switch.
Push- cuts out intermittent cabin altitude warning horn.
Cabin altitude warning horn sounds when cabin altitude is greater than 10,000 feet.
Explain the meaning of an illuminated WING-BODY OVERHEAT light.
Left and Right
- left light indicates overheat from bleed air duct leak in left engine strut, left inboard wing leading edge, left air conditioning bay, keel beam or APU bleed air duct.
- right light indicates overheat from bleed air duct leak in right engine strut, right inboard wing leading edge or right air conditioning bay.
Explain the function of the Air Temperature (AIR TEMP) Source Selector.
SUPPLY DUCT
PASS CAB
PACK
SUPPLY DUCT – selects appropriate zone supply duct temperature.
PASS CAB – selects forward or aft passenger cabin temperature.
PACK – selects left or right pack temperatures.
Explain the meaning of an illuminated PACK light.
- Indicates pack trip off or failure of both primary and standby pack controls.
- During MASTER CAUTION recall, indicates failure of either primary or standby pack control. Extinguishes when Master Caution is reset.
Explain the meaning of an illuminated ZONE TEMP light.
CONT CAB
FWD CAB or AFT CAB
- CONT CAB indicates a duct temperature overheat or failure of the flight deck primary and standby temperature control.
- FWD CAB or AFT CAB indicates duct temperature overheat.
- During Master Caution light recall: - CONT CAB indicates failure of the flight deck primary or standby temperature control.
- Either FWD CAB or AFT CAB indicates failure of the associated zone temperature control.
- Lights will extinguish when Master Caution is reset.
Explain the meaning of an illuminated OFF (Schedule) SCHED DESCENT light.
The airplane descended before reaching the planned cruise altitude set in the FLT ALT indicator.
Note: If a flight is aborted in climb and returns to the takeoff airport, the controller programs the cabin to land at the takeoff field elevation without further pilot inputs. If the FLT ALT indicator is changed, the automatic abort capability to the original takeoff field elevation is lost.
Recall the function of the TRIM AIR Switch.
ON
OFF
ON – trim air pressure regulating and shutoff valve signaled open.
OFF – trim air pressure regulating and shutoff valve signaled closed.
Recall the function of the RECIRC FAN.
Reduces the air conditioning system pack load and the engine bleed air demand. Air from the passenger cabin and electrical equipment bay is drawn to the forward cargo bay where it is filtered and re-circulated to the mix manifold.
