Removal of the ADIRU Mount (Nominal Procedure)

TASK 34-12-51-000-001-A
Removal of the ADIRU Mount (Nominal Procedure)

CAUTION: AFTER YOU REMOVE THE ADIRU MOUNT, DO NOT PUT PRESSURE OR OBJECTS ON ITS SUPPORT, WHICH IS EASILY DAMAGED. IF YOU DO NOT OBEY THIS PRECAUTION, YOU CAN CAUSE DAMAGE TO THE SUPPORT.

ZONE: 120

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	CAP - BLANKING

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
120	AVIONICS COMPARTMENT
127BG

C. Referenced Information

REFERENCE	DESIGNATION
TASK 07-11-00-581-001-A	Lifting for Aircraft Maintenance Operations
TASK 25-71-00-000-801-A	Removal of the Umbrella Assembly
TASK 31-36-00-740-008-A	Access to the Parameter Call-Up Menus
TASK 34-10-00-860-004-A	Inertial Reference (IR) Alignment-Procedure
TASK 34-10-00-860-004-A-01	Automatic Inertial Reference (IR) Alignment-Procedure
TASK 34-10-00-860-004-A-02	Inertial Reference (IR) Alignment-Procedure to do a Check of the Links between each Flight Management and Guidance Computer (FMGC) and the three Air Data/Inertial Reference Units (ADIRUs)
TASK 34-12-34-000-001-A	Removal of the ADIRU
TASK 34-12-51-000-802-A	Removal of the ADIRU Mount (Alternative Procedure)
TASK 34-12-51-400-802-A	Installation of the ADIRU Mount without Alignment Tools
TASK 53-12-13-000-001-A	Removal of the avionics compartment floor panels
Aircraft Integrated Data System (AIDS) Decimal Values
ADIRU Mount ** ON A/C NOT FOR ALL
ADIRU Mount ** ON A/C NOT FOR ALL
ADIRU Mount ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 34-12-51-210-050-A

A. Check for General Condition
(1) Do a visual inspection of the structure and aircraft skin (from the outside of the aircraft) between FR20 and FR24 to make sure there is no damage.

NOTE: The visual inspection of the ADIRU mount support must be done carefully.

(2) Make sure that no entry was done in the logbook related to the IR, AFS or EFCS system during the last flight.
(3) Make sure that no failure or no warning related to the IR, AFS or EFCS system occurred during the last flight.
(4) Make sure that the aircraft is installed with criteria MPM 25753P4280 or SB 34-1123 which installs wiring between ADIRU3 and the DMU (attitude and true heading angle-data of ADIRU3 are only available when the aircraft is installed with one of these criteria).
(5) If one of the above conditions does not occur, do the alternative procedure for the removal of the ADIRU mount (Ref. AMM TASK 34-12-51-000-802).

Subtask 34-12-51-582-050-A

B. Lift the aircraft on the jacks (Ref. AMM TASK 07-11-00-581-001)

NOTE: The safety stay is put in position only after the aircraft is on jacks.

Subtask 34-12-51-865-053-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 1FP1 (ADIRU1)
49VU	NAV PROBES/ADIRU 1/AND AOA 1/26VAC	5FP1	F07
49VU	NAV PROBES/ADIRU1/115VAC	4FP1	F06
105VU	ADIRS/ADIRU1/28VDC	6FP1	C02
** ON A/C NOT FOR ALL
FOR FIN: 1FP2 (ADIRU2)
121VU	ADIRS/ADIRU/2PWR/SHED	10FP	N10
** ON A/C ALL
121VU	ADIRS/ADIRU/2/26VAC AND AOA	5FP2	N08
121VU	ADIRS/ADIRU/2/115VAC	4FP2	N06
121VU	ADIRS/ADIRU/2/28VDC	6FP2	N04
** ON A/C NOT FOR ALL
121VU	ADIRS/2PWR/SHED &/AOA2 MON	10FP	N10
** ON A/C NOT FOR ALL
FOR FIN: 1FP3 (ADIRU3)
49VU	NAV PROBES/ADIRU3/PWR/SWTG	8FP	F09
** ON A/C NOT FOR ALL
49VU	NAV PROBES/ADIRU3/PWR/SWTG	8FP	F08
** ON A/C ALL
121VU	ADIRS/ADIRU/3PWR/SWTG	9FP	N09
121VU	ADIRS/ADIRU/3/26VAC AND AOA	5FP3	N07
121VU	ADIRS/ADIRU/3/115VAC	4FP3	N05
121VU	ADIRS/ADIRU/3/28VDC	6FP3	N03

Subtask 34-12-51-720-052-A

D. Crosscheck of the Roll, Pitch and Heading Angles
(1) Do the (automatic, if applicable) Inertial Reference (IR) alignment procedure of Air Data/Inertial Reference Unit 1 (ADIRU1), ADIRU2 and ADIRU3 (Ref. AMM TASK 34-10-00-860-004).
(2) Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).
(3) Get the pitch angle (label 324), roll angle (label 325) and true heading angle (label 314) of ADIRU1, ADIRU2 and ADIRU3 with a label call-up procedure.

NOTE: The number of digits of the equipment parameter code that you must enter (two or three digits) is related to the installed Data Management Unit/Flight Data Interface and Management Unit (DMU/FDIMU) equipment (hardware and software versions).
The procedure and the table that follow show three digits. If you cannot enter the three digits, enter the last two digits: for example, enter 04 for 004.

ACTION	RESULT
1.On the MCDU, on the AIDS: LAB CALL-UP 1/8 page: For the pitch of IR1 (1FP1), enter 004/1/324/01/18 in the scratchpad then push the line select key adjacent to the first arrow.	On the MCDU, on the AIDS: LAB CALL-UP 1/8 page: The related label and databits come into view.
For the pitch of IR2 (1FP2), enter 004/2/324/10/18 in the scratchpad then push the line select key adjacent to the second arrow.	The related label and databits come into view.
Push the line select key adjacent to the PRINT indication and print this page.
On the MCDU keyboard, push the Next Page key.	The AIDS: LAB CALL-UP 2/8 page comes into view.
2.On the MCDU, on the AIDS: LAB CALL-UP 2/8 page: For the pitch of IR3 (1FP3), enter 004/3/324/11/18 in the scratchpad then push the line select key adjacent to the first arrow.	On the MCDU, on the AIDS: LAB CALL-UP 2/8 page: The related label and databits come into view.
For the roll of IR1 (1FP1), enter 004/1/325/01/18 in the scratchpad then push the line select key adjacent to the first arrow.	The related label and databits come into view.
Push the line select key adjacent to the PRINT indication and print this page.
On the MCDU keyboard, push the Next Page key.	The AIDS: LAB CALL-UP 3/8 page comes into view.
3.On the MCDU, on the AIDS: LAB CALL-UP 3/8 page: For the roll of IR2 (1FP2), enter 004/2/325/10/18 in the scratchpad then push the line select key adjacent to the first arrow.	On the MCDU, on the AIDS: LAB CALL-UP 3/8 page: The related label and databits come into view.
For the roll of IR3 (1FP3), enter 004/3/325/11/18 in the scratchpad then push the line select key adjacent to the first arrow.	The related label and databits come into view.
Push the line select key adjacent to the PRINT indication and print this page.
On the MCDU keyboard, push the Next Page key.	The AIDS: LAB CALL-UP 4/8 page comes into view.
4.On the MCDU, on the AIDS: LAB CALL-UP 4/8 page: For the heading of IR1 (1FP1), enter 004/1/314/01/18 in the scratchpad then push the line select key adjacent to the first arrow.	On the MCDU, on the AIDS: LAB CALL-UP 4/8 page: The related label and databits come into view.
For the heading of IR2 (1FP2), enter 004/2/314/10/18 in the scratchpad then push the line select key adjacent to the first arrow.	The related label and databits come into view.
Push the line select key adjacent to the PRINT indication and print this page.
On the MCDU keyboard, push the Next Page key.	The AIDS: LAB CALL-UP 5/8 page comes into view.
5.On the MCDU, on the AIDS: LAB CALL-UP 5/8 page: For the heading of IR3 (1FP3), enter 004/3/314/11/18 in the scratchpad then push the line select key adjacent to the first arrow.	On the MCDU, on the AIDS: LAB CALL-UP 5/8 page: The related label and databits come into view.
Push the line select key adjacent to the PRINT indication and print this page.

(4) Record the pitch, roll and heading angle values that you got.

NOTE: You will use these values during the installation of the ADIRU mount without the alignment tools.

(5) Compare the values (1) and the Sign Status Matrices (SSM) (2) that you recorded during the test with the values of the table that follows:

Aircraft Integrated Data System (AIDS) Decimal Values

COMPARE THE DATA THAT FOLLOW:	THE TEST IS OK IF:
1.Values (1) of PITCH from IR1 and of PITCH from IR3	The SSMs (2) of PITCH1 and PITCH3 are equal, the test is OK if the difference between the values (1) is as follows: \|PITCH1-PITCH3\| < 583 The SSMs (2) of PITCH1 and PITCH3 are not equal, the test is OK if the difference between the values (1) is as follows: \|PITCH1-PITCH3\| > 261560
2.Values (1) of PITCH from IR2 and of PITCH from IR3	The SSMs (2) of PITCH2 and PITCH3 are equal, the test is OK if the difference between the values (1) is as follows: \|PITCH2-PITCH3\| < 583 The SSMs (2) of PITCH2 and PITCH3 are not equal, the test is OK if the difference between the values (1) is as follows: \|PITCH2-PITCH3\| > 261560
3.Values (1) of PITCH from IR1 and of PITCH from IR2	The SSMs (2) of PITCH1 and PITCH2 are equal, the test is OK if the difference between the values (1) is as follows: \|PITCH1-PITCH2\| < 583 The SSMs (2) of PITCH1 and PITCH2 are not equal, the test is OK if the difference between the values (1) is as follows: \|PITCH1-PITCH2\| > 261560
4.Values (1) of ROLL from IR1 and of ROLL from IR3	The SSMs (2) of ROLL1 and ROLL3 are equal, the test is OK if the difference between the values (1) is as follows: \|ROLL1-ROLL3\| < 583 The SSMs (2) of ROLL1 and ROLL3 are not equal, the test is OK if the difference between the values (1) is as follows: \|ROLL1-ROLL3\| > 261560
5.Values (1) of ROLL from IR2 and of ROLL from IR3	The SSMs (2) of ROLL2 and ROLL3 are equal, the test is OK if the difference between the values (1) is as follows: \|ROLL2-ROLL3\| < 583 The SSMs (2) of ROLL2 and ROLL3 are not equal, the test is OK if the difference between the values (1) is as follows: \|ROLL2-ROLL3\| > 261560
6.Values (1) of ROLL from IR1 and of ROLL from IR2	The SSMs (2) of ROLL1 and ROLL2 are equal, the test is OK if the difference between the values (1) is as follows: \|ROLL1-ROLL2\| < 583 The SSMs (2) of ROLL1 and ROLL2 are not equal, the test is OK if the difference between the values (1) is as follows: \|ROLL1-ROLL2\| > 261560
7.Values (1) of TRUE HEADING from IR1 and of TRUE HEADING from IR3	For the ADIRU alignment between 78.25°S and 78.25°N: The SSMs (2) of TRUE HEADING1 and TRUE HEADING3 are equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING3\| < 1457 The SSMs (2) of TRUE HEADING1 and TRUE HEADING3 are not equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING3\| > 260686 For the ADIRU alignment between 78.25°N and 82°N: The SSMs (2) of TRUE HEADING1 and TRUE HEADING3 are equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING3\| < 2331 The SSMs (2) of TRUE HEADING1 and TRUE HEADING3 are not equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING3\| > 259812
8.Values (1) of TRUE HEADING from IR2 and of TRUE HEADING from IR3	For the ADIRU alignment between 78.25°S and 78.25°N: The SSMs (2) of TRUE HEADING2 and TRUE HEADING3 are equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING2-TRUE HEADING3\| < 1457 The SSMs (2) of TRUE HEADING2 and TRUE HEADING3 are not equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING2-TRUE HEADING3\| > 260686 For the ADIRU alignment between 78.25°N and 82°N: The SSMs (2) of TRUE HEADING2 and TRUE HEADING3 are equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING2-TRUE HEADING3\| < 2331 The SSMs (2) of TRUE HEADING2 and TRUE HEADING3 are not equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING2-TRUE HEADING3\| > 259812
9.Values (1) of TRUE HEADING from IR1 and of TRUE HEADING from IR2	For the ADIRU alignment between 78.25°S and 78.25°N: The SSMs (2) of TRUE HEADING1 and TRUE HEADING2 are equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING2\| < 1457 The SSMs (2) of TRUE HEADING1 and TRUE HEADING2 are not equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING2\| > 260686 For the ADIRU alignment between 78.25°N and 82°N: The SSMs (2) of TRUE HEADING1 and TRUE HEADING2 are equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING2\| < 2331 The SSMs (2) of TRUE HEADING1 and TRUE HEADING2 are not equal, the test is OK if the difference between the values (1) is as follows: \|TRUE HEADING1-TRUE HEADING2\| > 259812

(6) If one of the checks is not correct, contact the Airbus Customer Services.

Subtask 34-12-51-020-059-C

E. Get Access
(1) Remove the umbrella assembly (Ref. AMM TASK 25-71-00-000-801).
(2) Remove aft avionics-compartment floor-panel 127BG (Ref. AMM TASK 53-12-13-000-001).

Subtask 34-12-51-020-050-A

F. Identify the location of each ADIRU (1FP1, 1FP2 and 1FP3) and remove them (Ref. AMM TASK 34-12-34-000-001).

4. Procedure
Subtask 34-12-51-020-051-A ** ON A/C NOT FOR ALL

CAUTION: AFTER YOU REMOVE THE ADIRU MOUNT, DO NOT PUT PRESSURE OR OBJECTS ON ITS SUPPORT, WHICH IS EASILY DAMAGED. IF YOU DO NOT OBEY THIS PRECAUTION, YOU CAN CAUSE DAMAGE TO THE SUPPORT.

A. Removal of the ADIRU Mount

ADIRU Mount ** ON A/C NOT FOR ALL

(1) Remove the nuts (4), washers (8) and screws (7) which attach the bonding leads (5) to the mount (13).
(2) Remove the nuts (14) from the screws (11).
(3) Remove the electrical connectors (12) from the mount (13). Use some straps to attach the electrical connectors (12).
(4) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(5) Remove the nuts (1), washers (2) and screws (6).
(6) Lift the mount (13) off its support. Be careful not to cause damage to the peel shims (3) and the air conditioning pipe (9).
(7) Put marks on the peel shims (3) with a felt-tip pen or equivalent, to make sure that you put them back in their initial positions when you install the mount (13).

NOTE: The peel shims below the mount and their related positions must be clearly identified to put them back in their initial positions.

(8) Remove the nuts (10).
(9) Remove the air conditioning pipe (9).
(10) Remove the mount (13).

Subtask 34-12-51-020-051-B ** ON A/C NOT FOR ALL

CAUTION: AFTER YOU REMOVE THE ADIRU MOUNT, DO NOT PUT PRESSURE OR OBJECTS ON ITS SUPPORT, WHICH IS EASILY DAMAGED. IF YOU DO NOT OBEY THIS PRECAUTION, YOU CAN CAUSE DAMAGE TO THE SUPPORT.

A. Removal of the ADIRU Mount

ADIRU Mount ** ON A/C NOT FOR ALL

(1) Remove the screws (9) and the washers (8) which attach the bonding leads (7) to the mount (2).
(2) Remove the screws (12) from the electrical connectors (14).
(3) Remove the plates (13) and the electrical connectors (14) from the mount (2). Use some straps to attach the electrical connectors (14).
(4) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(5) Remove the nuts (6), washers (5) and bolts (3).
(6) Remove the nuts (10), washers (11) and bolts (1).
(7) Lift the mount (2) off its support. Be careful not to cause damage to the peel shims (4).
(8) Put marks on the peel shims (4) with a felt-tip pen or equivalent, to make sure that you put them back in their initial positions when you install the mount (2).

NOTE: The peel shims below the mount and their related positions are clearly identified to put them back in their initial positions.

(9) Remove the mount (2).

5. Close-up
Subtask 34-12-51-860-050-A

A. Do the installation of the ADIRU mount without alignment tools (Ref. AMM TASK 34-12-51-400-802).

[Rev.10 from 2021] 2026.04.02 07:24:32 UTC