AIR Control Panel
Overview
The AIR Control Panel manages cabin air conditioning and pressurization by controlling airflow from the engine, APU, and ram air sources. It includes switches and knobs for controlling packs, bleed valves, temperature zones, and air distribution systems. This panel ensures cabin comfort and safety through precise regulation of airflow and temperature.
Panel Components
PACK FLOW Switch
- Toggles between economy and maximum flow mode for the air conditioning packs.
- Pushed: Packs operate in high-flow mode, maximizing air supply.
- Released: Packs operate in economy mode, adjusting flow based on the number of passengers.
L (R) PACK Switch
- Controls the left or right air conditioning pack.
- Pushed: The IASC (Integrated Air System Controller) manages the valve automatically; the pack operates normally.
- Released: Valve is closed; the pack is shut down.
- FAULT: Indicates failure of the respective pack.
Emergency RAM AIR Switch
- Controls the emergency ram air valve.
- Pushed: Valve is fully open, allowing outside air into the cabin.
- Released: Valve remains closed to prevent unfiltered air from entering.
Note
This switch is typically used only in emergency or smoke removal scenarios.
TRIM AIR Switch
- Manages the trim air system used for fine-tuning cabin temperature.
- Pushed: System operates normally.
- Released: System stops providing trim air.
- FAULT: Indicates a system failure.
RECIRC Switch
- Controls recirculation fans for airflow efficiency.
- Pushed: Fans operate based on cargo ventilation configuration:
- If both FWD and AFT ventilation are on, both fans operate.
- If only FWD is on, only the left fan runs.
- If only AFT is on, only the right fan runs.
- If both are off, fans alternate based on flight conditions.
- Released: Recirculation fans are disabled.
Note
With recirculation off, FWD and AFT service area heaters are not available.
AFT CABIN Temperature Knob
- Adjusts AFT cabin temperature between 18°C and 30°C.
- 12 o’clock position sets temperature to 24°C.
FWD CABIN Temperature Knob
- Adjusts forward cabin temperature between 18°C and 30°C.
- 12 o’clock position sets temperature to 24°C.
COCKPIT Temperature Knob
- Adjusts cockpit temperature between 18°C and 30°C.
- 12 o’clock position sets temperature to 24°C.
L(R) ENG BLEED Switch
- Controls engine bleed air supply.
- Pushed: PRSOV (Pressure Regulating and Shutoff Valve) is in AUTO.
- Released: PRSOV is closed; no bleed air is supplied.
- FAULT: Engine bleed air system failure on the respective side.
APU BLEED Switch
- Controls APU (Auxiliary Power Unit) bleed air.
- Pushed: APU bleed air is enabled.
- Released: APU bleed air is disabled.
- FAULT: APU bleed air system failure.
X BLEED Selector
- Manages the cross bleed valve for air distribution between left and right sides.
- AUTO: Controlled automatically by IASC.
- CLOSED: Valve is shut, isolating the bleed air systems.
- OPEN: Valve is opened, allowing cross-bleed airflow.