DOC AIRBUS | AMM A320FLP COMPRESSOR AIRFLOW CONTROL SYSTEM - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
A. The primary function of the LP compressor airflow control system is to control the airflow thus ensuring compressor stable operation during:
- Engine start.
- Engine transient operation.
2. Description
A. General
- the airflow control system includes:
(1) An LPC bleed-slave actuator
(2) An LPC bleed-master actuator
(3) Two bleed-valve actuating rods
(4) A booster bleed valve and actuating mechanism The airflow control system automatically operates to control the air bled from the LP compressor.
The two actuators are mechanically attached to each actuating rod and, the bleed-valve and actuating mechanism. The two actuators are connected hydraulically and operate together by command and feedback signals from/ to the EEC.
The two actuators are mechanically attached to each actuating rod and, the bleed-valve and actuating mechanism. The two actuators are connected hydraulically and operate together by command and feedback signals from/ to the EEC.
B. LPC Bleed-Master and Slave Actuators
LPC Bleed Master and Slave Actuators(1) Description
- The two actuators are hydraulically connected units which operate together. Each of them is attached to a bracket on the intermediate structure.
- The two bleed-valve actuating rods connect each actuator fork end to the synchronizing ring. The force to move the synchronizing and its linkage through the actuating rods, is supplied from the two actuators.
- The master actuator gives an accurate control in relation to an electrical input signal (command signal) from the EEC. The master actuator also gives an electrical output signal (the positions of the actuator piston fork end) to an electrical input signal (command signal) from the EEC. The master actuator also gives an electrical output signal (the positions of the actuator piston fork end) to the EEC.
(2) Operation
- the two actuators open or close in relation to the input signal from the EEC.
C. Booster Bleed Valve and Actuating Mechanism
(1) Description
- The bleed valve and actuating mechanism operates to make each bleed valve synchronized, in relation to the positions of the two actuators.
- The bleed valve and actuating mechanism is a sub-assembly which includes:
- The support ring.
- The ring valve
- The two upper arms, the lower arms and the eight mid arms.
(2) Operation
- The ring valve opens during the engine start and other scheduled flight operations. This permits some of the LP compressor airflow (which normally go into the HP compressor) to go through the fan airstream. The bleed valves are closed during takeoff and cruise operations.