DOC AIRBUS | AMM A320FAIR - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The air system has two subsystems:
The air system has two subsystems:
- Bleed and Surge Air,
- Accessory Cooling.
A. Bleed and Surge Air
The bleed and surge-air system controls the supply of the APU bleed air to the pneumatic system of the aircraft and prevents a load compressor surge (Ref. 49-51-00).
The bleed and surge-air system supplies the APU bleed air for:
The bleed and surge-air system controls the supply of the APU bleed air to the pneumatic system of the aircraft and prevents a load compressor surge (Ref. 49-51-00).
The bleed and surge-air system supplies the APU bleed air for:
- the main engine start,
- the air-conditioning.
B. Accessory Cooling
The accessory cooling system supplies cooling air to the APU oil cooler and to the APU compartment. The system operates independently of the APU load compressor and the bleed and surge-air system (Ref. AMM D/O 49-52-00-00).
The accessory cooling system supplies cooling air to the APU oil cooler and to the APU compartment. The system operates independently of the APU load compressor and the bleed and surge-air system (Ref. AMM D/O 49-52-00-00).
2. System Description
A. Bleed and Surge Air
The APU load compressor supplies the APU bleed air. The quantity changes with the different bleed air demands of the pneumatic systems. Variable Inlet Guide Vanes (IGVs) (which are installed at the load compressor inlet) control the quantity of the bleed air.
An APU bleed control valve is installed at the scroll outlet on the right lower part of the APU. The APU bleed control valve controls the air from the load compressor to the exhaust or to the pneumatic system of the aircraft.
The Electronic Control Box (ECB) 59KD controls and monitors the APU bleed air supply and the surge air flow. You start and stop the bleed air supply with the APU BLEED pushbutton switch, which is on the AIR overhead panel 30VU in the cockpit.
The APU load compressor supplies the APU bleed air. The quantity changes with the different bleed air demands of the pneumatic systems. Variable Inlet Guide Vanes (IGVs) (which are installed at the load compressor inlet) control the quantity of the bleed air.
An APU bleed control valve is installed at the scroll outlet on the right lower part of the APU. The APU bleed control valve controls the air from the load compressor to the exhaust or to the pneumatic system of the aircraft.
The Electronic Control Box (ECB) 59KD controls and monitors the APU bleed air supply and the surge air flow. You start and stop the bleed air supply with the APU BLEED pushbutton switch, which is on the AIR overhead panel 30VU in the cockpit.
B. Accessory Cooling
The accessory cooling system operates independently of the APU load compressor and the bleed and surge-air system.
A cooling fan supplies sufficient cooling air to the oil cooler to keep the lubricating oil in the correct temperature range. It also supplies cooling air to the APU compartment to remove the heat which comes from the APU surface.
The cooling fan is of the one-stage axial-flow type and the accessory drive gearbox turns the cooling fan rotor.
The compartment cooling air flows through an outlet and into the APU compartment.
The accessory cooling system operates independently of the APU load compressor and the bleed and surge-air system.
A cooling fan supplies sufficient cooling air to the oil cooler to keep the lubricating oil in the correct temperature range. It also supplies cooling air to the APU compartment to remove the heat which comes from the APU surface.
The cooling fan is of the one-stage axial-flow type and the accessory drive gearbox turns the cooling fan rotor.
The compartment cooling air flows through an outlet and into the APU compartment.