# Airbus Alert Operators Transmission A32N030-23

Copy: No revision named ("AOT - A32N030-23 - with appendices"), 8 pages: PDF https://openairdocs.org/files/sha256/30/27/302769eb30484c81eb1c8a1ea3efc4d1cda324a5def6bc95d32e630acfa5fea3; text https://openairdocs.org/service-documents/airbus/aot-a32n030-23/file/302769eb3048.md. Rights: © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2023-1882; AD 2023-25-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.

## Details

- Manufacturer: [Airbus](https://openairdocs.org/service-documents/airbus.md)
- Type: Other document (Alert Operators Transmission)
- Number: A32N030-23
- Page: https://openairdocs.org/service-documents/airbus/aot-a32n030-23

## ADs that cite it (1) (OpenAirDocs)

Newest first, with the revision each names, as OpenAirDocs read it from the AD's text.

- [AD 2023-25-05](https://openairdocs.org/ad/2023-25-05.md), effective Feb 7, 2024: No revision named

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/airbus/aot-a32n030-23/proposed.md).

## Text (8 pages)

Rights: © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2023-1882; AD 2023-25-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

CUSTOMER SERVICES DIRECTORATE
2 ROND POINT EMILE DEWOITINE
31700 BLAGNAC FRANCE
TELEPHONE + 33 (0)5 61 93 33 33
ALERT OPERATORS TRANSMISSION - AOT
AOT ref: A32N030-23 Rev 00 Page 1 of 8 Date: 27-FEB-2023
C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
SUBJECT: ATA 32 – A320FAM incorrect relay installation at FIN 24GG/25GG during Manufacturing
AIRCRAFT TYPE:  A319-100N, A320-200N, A321-200NX
OUR REF.: A32N030-23 Rev 00 dated 27-FEB-2023
EFFECTIVITY DATE: 01-Mar-2023
1. AIRCRAFT AFFECTED
Models Affected:
A319-153N, A320-251N, A320-271N, A320-272N, A321-251NX, A321-252NX, A321-253NX, 
A321-271NX, A321-272NX
MSNs affected:
9540, 10127, 10128, 10142, 10146, 10161, 10188, 10272, 10275, 10284, 10331, 10353, 10400, 10420, 
10434, 10448, 10486, 10546, 10620, 10637, 10644, 10655, 10658, 10674, 10701, 10703, 10714, 
10724, 10729, 10737, 10741, 10756, 10776, 10779, 10780, 10788, 10789, 10795, 10797, 10798, 
10803, 10809, 10814, 10816, 10819, 10828, 10831, 10832, 10833, 10837, 10839, 10842, 10848, 
10850, 10853, 10854, 10855, 10861, 10862, 10866, 10873, 10875, 10878, 10881, 10882, 10884, 
10885, 10886, 10887, 10888, 10890, 10893, 10896, 10898, 10900, 10901, 10902, 10903, 10904, 
10907, 10908, 10909, 10911, 10912, 10914, 10916, 10917, 10918, 10919, 10921, 10922, 10923, 
10924, 10925, 10927, 10932, 10933, 10934, 10935, 10937, 10938, 10939, 10940, 10941, 10942, 
10947, 10949, 10950, 10951, 10952, 10954, 10957, 10958, 10960, 10961, 10962, 10963, 10964, 
10965, 10966, 10967, 10969, 10970, 10972, 10973, 10975, 10976, 10977, 10979, 10980, 10981, 
10982, 10983, 10984, 10985, 10986, 10987, 10988, 10989, 10990, 10992, 10993, 10995, 10996, 
10997, 10998, 11002, 11003, 11004, 11005, 11006, 11007, 11008, 11010, 11011, 11012, 11013, 
11014, 11015, 11016, 11017, 11018, 11019, 11020, 11021, 11022, 11023, 11024, 11025, 11026, 
11027, 11028, 11030, 11031, 11032, 11033, 11034, 11035, 11036, 11037, 11038, 11039, 11040, 
11041, 11042, 11043, 11044, 11045, 11047, 11048, 11049, 11050, 11051, 11052, 11053, 11054, 
11055, 11056, 11057, 11059, 11060, 11061, 11062, 11064, 11065, 11066, 11067, 11068, 11069, 
11070, 11071, 11073, 11074, 11075, 11076, 11077, 11078, 11079, 11081, 11082, 11083, 11085, 
11086, 11087, 11088, 11090, 11091, 11092, 11094, 11097, 11099, 11100, 11102, 11103, 11105, 
11108, 11109, 11111, 11112, 11114, 11116, 11117, 11118, 11120, 11121, 11122, 11123, 11124, 
11126, 11127, 11128, 11130, 11133, 11135, 11137, 11138, 11139, 11140, 11141, 11142, 11143, 
11145, 11146, 11148, 11149, 11150, 11151, 11152, 11153, 11154, 11155, 11157, 11159, 11160, 
11161, 11162, 11166, 11169, 11173, 11174, 11175, 11178, 11180, 11181, 11182, 11188, 11189, 
11190, 11193, 11194, 11195, 11197, 11199, 11201, 11205, 11211, 11213, 11216, 11222, 11224, 
11228, 11232, 11234, 11235, 11244, 11245, 11247, 11252, 11254, 11258, 11261, 11265, 11270, 
11271, 11282, 11287, 11288, 11293 and 11295.
2. REFERENCED DOCUMENTATION
2.1 APPENDIX
Appendix 1 - General Overview of 24GG/25GG relays location
Appendix 2 - Flowchart
2.2 REFERENCES
Reference 1: TFU 32.42.00184 - A320FAM BSCU P/N E21327307 increased rate of BRAKES SYS 
1(2) FAULT detected prior to delivery

### Page 2

ALERT OPERATORS TRANSMISSION - AOT 
AOT ref: A32N030-23 Rev 00 Page 2 of 8 Date: 27-FEB-2023
C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
Reference 2: EASA AD 2022-0032 rev. 02
Reference 3: AMM Task 12-34-24-869-002
Reference 4: AMM Task 24-41-00-862-002
Reference 5: AMM Task 52-41-00-010-002
Reference 6: AMM Task 52-41-00-410-002
Reference 7: AMM Task 21-61-34-000-002
Reference 8: AMM Task 21-61-34-400-002
Reference 9: AMM Task 24-41-00-861-002
Reference 10: AMM Task 24-50-00, Page Block 00
Reference 11: AMM Task 31-60-00-860-001 
Reference 12: AMM Task 32-31-71-000-001
Reference 13: AMM Task 32-31-71-400-001
Reference 14: AMM Task 32-42-34-000-001
Reference 15: AMM Task 32-42-34-400-001
Reference 16: ESPM 20-46-50 
Reference 17: ESPM 20-52-21
Reference 18: ESPM 20-55-00
3. REASON
3.1 FACTS
Airbus informs the operators that some aircraft post-MOD 171984 within the effectivity list of this AOT 
could have an incorrect 24GG/25GG relay configuration and requests operators to visually inspect the 
aircraft and confirm correct relays are installed.
3.2 HISTORY/BACKGROUND
End of January 2023, following the troubleshooting of a Braking & Steering Control unit (BSCU) fault 
triggered on an aircraft during Flight Line Rejected Take-Off (RTO) testing, it was noticed that the relays 
present on aircraft at 24GG / 25GG FIN locations were not in line with the relays expected at these 
locations for this aircraft configuration.
Indeed, based on subject aircraft configuration (post-MOD 171984), the expected relays for FIN 24GG / 
25GG should be P/N E0669D28A0 (Type 2 / suppressed relays) whereas P/N E0244-28A0 (Type 1 / 
unsuppressed relays) were found installed.
3.3 ROOT CAUSE
At the time of this AOT issuance the root cause investigation is still on-going.
Reinforced inspections have been put in place prior to aircraft delivery starting from the 26th of January 
2023 to ensure the correct relay configuration of the aircraft delivered.
3.4 INVESTIGATION
Investigation is on-going.
3.5 CONSEQUENCES
As described in TFU 32.42.00184, the installation of unsuppressed relay at FIN 24GG / 25GG locations 
was identified as a contributor to the increased rate of BRAKES SYS 1/2 FAULTS and NWS ANTI-SKID 
FAULTS when combined with the increased sensitivity of BSCU P/N E21327307.

### Page 3

ALERT OPERATORS TRANSMISSION - AOT 
AOT ref: A32N030-23 Rev 00 Page 3 of 8 Date: 27-FEB-2023
C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
4. OBJECTIVES OF THIS AOT
This AOT recommends the visual inspection of the 24GG/25GG FIN locations to confirm the P/N of 
the relays installed, and, in case of finding, the replacement of the relays by the correct P/N.
5. MAINTENANCE PROCEDURE
NOTE: This AOT is classified mandatory or expected to be classified mandatory by an Airworthiness 
Directive (AD). If the instructions of this AOT are marked as Required for Compliance (RC), the 
operator must follow the instructions as indicated. These instructions are introduced by “in 
accordance with”.
NOTE: The instructions of this AOT include procedures given in other documents or in other sections 
of the AOT. If the instructions of this AOT are NOT marked as Required for Compliance (RC), the 
operator can use an alternative procedure accepted by his/her local authority. These instructions 
are introduced by “refer to”.
NOTE: When this AOT gives the access or close-up instructions with no return to service tests, the 
operator can adapt these instructions to add flexibility to the maintenance operations. The technical 
intent of this AOT must comply with the set parameters.
5.1 PLANNING – (RC)
The inspection and corrective action detailed in this AOT shall be performed within 12 months 
following effectivity date of this AOT.
5.2 MANPOWER
Estimated Man Hours for inspections phase:
- Job Set up: 1.4 MH
- Inspection: 0.1 MH
- Close up: 0.5 MH
Estimated Man Hours for corrective action in case of finding:
- Job Set up: 1.5MH
- Relay replacement : 0.5 MH
- Preparation for test: 0.5 MH
- Test : 3.5 MH
- Close up: 0.5 MH 
5.3 ACCESS
- Make sure that the aircraft is electrically grounded, refer to Ref. AMM Task 12-34-24-869-002 
[Ref. 3].
- De-energize the aircraft electrical circuits, refer to Ref. AMM Task 24-41-00-862-002 [Ref. 4].
- Put an access platform in position below the avionics compartment door 811.
- Open the avionics compartment door 811, refer to Ref. AMM Task 52-41-00-010-002 [Ref. 5].
5.4 INSPECTION – (RC)
- Visually inspect and record the Part Number of the relays installed on FIN location 24GG and FIN 
location 25GG.
- Check if the Part Number installed is P/N E0669D28A0.
5.5 FINDINGS – (RC)

### Page 4

ALERT OPERATORS TRANSMISSION - AOT 
AOT ref: A32N030-23 Rev 00 Page 4 of 8 Date: 27-FEB-2023
C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
- If the Part Number installed on FIN 24GG and 25GG IS P/N E0669D28A0 then :
oMake sure that the work areas are clean and clear of tools and other items of 
equipment.
oClose the avionics compartment door 811, refer to Ref. AMM Task 52-41-00-410-002.
oRemove the access platform(s).
oPut the aircraft back to its initial configuration.
oReport accomplishment of this AOT to Airbus.
- If the Part Number installed on FIN 24GG and/or 25GG IS NOT P/N E0669D28A0 then :
oReport the finding to Airbus,
oApply the corrective action provided in §5.6 of this AOT within the compliance time 
provided in §5.1
5.6 INSTRUCTIONS – (RC)
In case of finding(s) during inspection described in §5.4 (i.e. one or two of the 24GG/25GG relays does 
not have P/N E0669D28A0), Operator shall replace affected relay(s) using the procedure below within 
the accomplishment timeframe described in §5.1.
Job Set-up:
(a) Make sure that the aircraft is electrically grounded, refer to Ref. AMM Task 12-34-24-869-002 
[Ref.3].
(b) De-energize the aircraft electrical circuits, refer to Ref. AMM Task 24-41-00-862-002 [Ref. 4].
(c) Put an access platform in position below the avionics compartment door 811.
(d) Open the avionics compartment door 811, refer to Ref. AMM Task 52-41-00-010-002 [Ref.5].
(e) Open, safety/lock and tag these circuit breakers: 1GG, 2GG, 3GG, 4GG
NOTE: For the circuit breaker location, refer to Ref. AMM 24-50-00, Page Block 00 [Ref. 10].
(f) Remove the Landing Gear Control and Interface Unit (LGCIU) 1, FIN 5GA1, and LGCIU 2, 
FIN 5GA2, refer to Ref. AMM Task 32-31-71-000-001 [Ref. 12].
(g) Remove the BSCU, FIN 10GG, refer to Ref. AMM Task 32-42-34-000-001 [Ref. 14].
(h) Remove the Air Conditioning System Controller (ACSC) 1, FIN 47HH, and ACSC 2, FIN 
57HH, refer to Ref. AMM Task 21-61-34-000-002 [Ref. 7].
Procedure:
(a) In the FWD avionics rack FIN 90VU, replace the relays 24GG and 25GG as per ESPM 20-46-
50 [Ref. 16] to have relay P/N E0669D28A0 installed on both locations
Preparation for test
(a) Remove the safety clips and/or tags and close/unlock these circuit breakers: 1GG, 2GG, 3GG & 
4GG
(b) Energize the aircraft electrical circuits, refer to Ref. AMM Task 24-41-00-861-002 [Ref. 9].
(c) Energize the following systems:
- Normal AC/DC power supply
- EFIS/ECAM
- SDAC
- CFDS
- MCDU
- FWC
- Cockpit Lights.
(d) Start the EIS procedure (upper ECAM DU and lower ECAM DU only), refer to Ref. AMM Task 
31-60-00-860-001 [Ref. 11].
Test

### Page 5

ALERT OPERATORS TRANSMISSION - AOT 
AOT ref: A32N030-23 Rev 00 Page 5 of 8 Date: 27-FEB-2023
C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
(a) On 121VU open the following C/B: 2GG & 4GG
(b) Connect the pin 10GG AA-11F to 10GG AB-15K (ground).
(c) Connect the pin 10GG AA-12F to 10GG AB-15A (ground).
(d) Confirm Open Circuit condition as per ESPM 20-52-21 [Ref. 17] on following connection:
- 47HH: AB-2C <-----> GND
- 57HH: AB-2C <-----> GND.
(e) Do a continuity check as per ESPM 20-52-21 [Ref.17] on following connection and confirm 
resistance within [0-5 Ohm] range:
- 5GA1: AA-9H <-----> GND
- 5GA2: AA-9H <-----> GND
(f) On 121VU close the following C/B: 2GG & 4GG
(g) Do a continuity check as per ESPM 20-52-21 [Ref. 17] on following connection and confirm 
resistance within [0-5 Ohm] range:
- 47HH: AB-2C <-----> GND
- 57HH: AB-2C <-----> GND.
(h) Confirm Open Circuit condition as per ESPM 20-52-21 [Ref. 17] on following connections:
- 5GA1: AA-9H <-----> GND
- 5GA2: AA-9H <-----> GND
(i) On 121VU open the following C/B: 2GG & 4GG
(j) Disconnect the pin 10GG AA-11F from 10GG AB-15K (ground).
(k) Disconnect the pin 10GG AA-12F to 10GG AB-15A (ground).
(l) On 121VU close the following C/B: 2GG & 4GG
(m) Install the LGCIU 1, FIN 5GA1, and LGCIU 2, FIN 5GA2, refer to Ref. AMM Task 32-31-71-
400-001 [Ref. 13].
(n) Install the BSCU, FIN 10GG, refer to Ref. AMM Task 32-42-34-400-001 [Ref. 15].
(o) Install the ACSC 1, FIN 47HH, and ACSC 2, FIN 57HH, refer to Ref. AMM Task 21-61-34-
400-002 [Ref. 8].
(p) Do the test after the installation of the LGCIU 1 and LGCIU 2, refer to Ref. AMM Task 32-31-
71-400-001 [Ref. 13].
(q) Do the test after the installation of the BSCU, refer to Ref. AMM Task 32-42-34-400-001 [Ref. 
15].
(r) Do the test after the installation of the ACSC 1 and ACSC 2, refer to Ref. AMM Task 21-61-
34-400-002 [Ref. 8].
Close up
(a)  Make sure that the work areas are clean and clear of tools and other items of equipment.
(b) Close the avionics compartment door 811, refer to Ref. AMM Task 52-41-00-410-002 [Ref. 6].
(c) Remove the access platform(s).
(d) Put the aircraft back to its initial configuration.
5.7 SPARES AND TOOLING
In case of finding during inspection described in §5.4, 1EA or 2EA of relay P/N E0669D28A0 will be 
required to put back the aircraft in correct configuration.
A dedicated commercial policy is being prepared and will be attached to TFU 32.42.00184.
6. ADDITIONAL INFORMATION
6.1 FOLLOW-UP PLAN

### Page 6

ALERT OPERATORS TRANSMISSION - AOT 
AOT ref: A32N030-23 Rev 00 Page 6 of 8 Date: 27-FEB-2023
C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
The inspection and corrective action described in this AOT are expected to be mandated in the frame 
of the future EASA AD mandating SB 92-1149 (ELECTRIC AND ELECTRONIC COMMON 
INSTALLATION – EQUIPMENT FOR BOXES AND PANELS - INTRODUCE SUPPRESSED RELAYS 
ON 24GG & 25GG).
6.2 IMPACTED DOCUMENTATION
N/A
7. AOT APPROVAL
The technical content of this document is approved under the authority of the DOA ref.EASA.21J.031.
8. REPORTING
Address your inspection results (with or without findings) to Airbus Customer Services through the generic 
e-mail address. Refer to the latest reporting policy (Ref in the OIT 999.0018/16). 
Give the AOT reference in the mail title, as follows: AOT A32N030-23 Inspection Result
You can address your questions about this AOT to Airbus Customer Services through TechRequest 
on Airbus World, selecting Maintenance & Engineering Domain, Engineering Support Section and 
ATA 32-42/Topic AOT A32N030-23.
Best Regards,
Wolfgang WOHLERS
VICE PRESIDENT ENGINEERING SUPPORT
CUSTOMER SERVICES
Jean-Pierre GOMEZ
VICE PRESIDENT A320 FAM PROGRAMME
CUSTOMER SERVICES

### Page 7 (OCR)

CUSTOMER SERVICES DIRECTORATE  AIRBUS
2 ROND POINT EMILE DEWOITINE
31700 BLAGNAC FRANCE
TELEPHONE + 33 (0)5 61 93 33 33
AOT - Appendix 1 - General Overview of 24GG/25GG relays location
FR24A
Z120
FR1
TEND
90VU
RELAY
25GG
TO BE REPLACED
RELAY
24GG
TO BE REPLACED
B
Fig. A1: General Overview of 24GG/25GG relays location
AOT ref: A32N030-23 Rev 00  Page 7 of 8  Date: 21-February 2023
C80_AOT_FM1104649_v8.0  © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

### Page 8 (OCR)

CUSTOMER SERVICES DIRECTORATE  AIRBUS
2 ROND POINT EMILE DEWOITINE
31700 BLAGNAC FRANCE
TELEPHONE + 33 (0)5 61 93 33 33
AOT - Appendix 2 - Flowchart
START
Was aircraft delivered  NO
post-MOD 171984?
YES
Is aircraft within list of  NO
MSN affected by AOT?
YES
Visually inspect the P/N of relay 24GG/25GG installed on aircraft
Report AOT inspection Results to Airbus
NO  NO
Is 24GG relay P/N E0669D28A0?  Is 25GG relay P/N E0669D28A0?
YES
Replace 24GG relay by P/N E0669D28A0  Replace 25GG relay by P/N E0669D28A0
Report Relay replacement to Airbus  Report Relay replacement to Airbus
AND
No further action
Fig. A.2: Flowchart
AOT ref: A32N030-23 Rev 00  Page 8 of 8  Date: 21-February 2023
C80_AOT_FM1104649_V8.0  © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

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