DOC AIRBUS | AMM A320FPRESSURIZATION CONTROL - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. System Description
A. Automatic Operation
The system has two identical, independent, automatic systems. Each system has a Cabin Pressure Controller (CPC) which controls the pressure through a flap-type outflow valve.
In the automatic operation the CPCs use the data from the Flight Management and Guidance System (FMGS) and the Air Data/Inertial Reference System (ADIRS). The active CPC controls with the auto-motor the outflow valve to the demanded position. It also supplies data for indication on the Electronic Instrumentation System (EIS).
Only one CPC operates the system at the time, with the other system on hot standby. The change of control from one CPC to the other is fully automatic after each flight, on landing. The CPCs will also change in flight if there is a failure or part failure of one of the control systems.
The system has two identical, independent, automatic systems. Each system has a Cabin Pressure Controller (CPC) which controls the pressure through a flap-type outflow valve.
In the automatic operation the CPCs use the data from the Flight Management and Guidance System (FMGS) and the Air Data/Inertial Reference System (ADIRS). The active CPC controls with the auto-motor the outflow valve to the demanded position. It also supplies data for indication on the Electronic Instrumentation System (EIS).
Only one CPC operates the system at the time, with the other system on hot standby. The change of control from one CPC to the other is fully automatic after each flight, on landing. The CPCs will also change in flight if there is a failure or part failure of one of the control systems.
B. Semi-Automatic Operation
If the data from the FMGS is not available, the landing field elevation can be manually adjusted with the LDG ELEV selector on the CABIN PRESS overhead panel 25VU. Then the CPCs controls the outflow valve with data from the ADIRS and the LDG ELEV selector.
If the data from the FMGS is not available, the landing field elevation can be manually adjusted with the LDG ELEV selector on the CABIN PRESS overhead panel 25VU. Then the CPCs controls the outflow valve with data from the ADIRS and the LDG ELEV selector.
C. Manual Operation
The MAN V/S toggle-switch controls the manual motor of the outflow valve when the MAN SEL switch is selected to MAN. These controls are installed in the cockpit, on the CABIN PRESS overhead panel 25VU.
In manual mode, the backup channel of the CPC in position No. 1 is used. It has a pressure sensor to generate the excess cabin altitude warning and pressure outputs for the indication on the EIS.
The MAN V/S toggle-switch controls the manual motor of the outflow valve when the MAN SEL switch is selected to MAN. These controls are installed in the cockpit, on the CABIN PRESS overhead panel 25VU.
In manual mode, the backup channel of the CPC in position No. 1 is used. It has a pressure sensor to generate the excess cabin altitude warning and pressure outputs for the indication on the EIS.