Procedure for CFDS Switching to Back-up Mode

TASK 31-32-00-869-001-A
Procedure for CFDS Switching to Back-up Mode

NOTE: IGNORE ALL THE ECAM WARNINGS AS LONG AS THE COMPUTER IS IN THE MENU MODE.

ZONE: 210

1. Reason for the Job
To give the procedure to set the CFDS to the back-up channel manually. When there is a fault on the normal channel.
2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)

3. Job Set-up
Subtask 31-32-00-860-091-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002)

Subtask 31-32-00-865-051-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AUTO FLT/MCDU/1	11CA1	B01
121VU	CFDS/CFDIU/SPLY	2TW	J18
121VU	CFDS/CFDIU/BACK/UP	8TW	J17

4. Procedure
Subtask 31-32-00-860-092-A ** ON A/C NOT FOR ALL

A. Procedure for CFDS switching to back-up mode

ACTION	RESULT
Adjust the brightness of the MCDU 1 screen.
push the MCDU MENU mode key.	On the MCDU 1: the MCDU MENU page comes into view.
push the line key adjacent to the <CFDS indication.	the CFDS MENU page comes into view.
push the NEXT PAGE function key.	the second CFDS MENU page comes into view.
push the line key adjacent to the BACK-UP MODE indication.	the BACK-UP page comes into view, when there is a fault on the normal channel.
push the line key adjacent to the SYSTEM REPORT/TEST indication.	the SYSTEM REPORT/TEST page of the back-up mode comes into view.
set the necessary system: Push the line key adjacent to the name of the system (for some systems, use the NEXT PAGE function key).	the page of the system set comes into view.

5. Close-up
Subtask 31-32-00-860-093-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) On the MCDU, push the line select key adjacent to the RETURN indication until the CFDS menu page comes into view.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002)

[Rev.10 from 2021] 2026.04.01 00:33:29 UTC