DOC AIRBUS | TSM A320FResidual Ground Speed Out of Limit of IR1 (or IR3) on the CAPT ND
TASK 34-14-00-810-927-A
Residual Ground Speed Out of Limit of IR1 (or IR3) on the CAPT ND
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 34-14-00-710-083-A ** ON A/C NOT FOR ALL
Subtask 34-14-00-810-181-A
[Rev.8 from Aug 2018]
2026.04.04 04:32:50 UTC
Residual Ground Speed Out of Limit of IR1 (or IR3) on the CAPT ND
1. Possible Causes
- ADIRU1 or ADIRU3
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 34-12-34-000-001 | Removal of the ADIRU |
| AMM 34-12-34-400-001 | Installation of the ADIRU |
Subtask 34-14-00-710-083-A ** ON A/C NOT FOR ALL
A. At the end of the flight, do a check of the residual ground speed related to the IR1 on the CAPT ND.
Subtask 34-14-00-710-083-B ** ON A/C NOT FOR ALL - to read the residual ground speed related to the IR3:
. set the ATT HDG selector switch to CAPT/3.
- set the DATA DISPLAY selector switch to TK/GS
- set the SYS DISPLAY selector switch to 1 (IR1) or 3 (IR3)
- read the related ground speed in the CDU display.
NOTE: The radial position error does not stay in the memory of the MCDU after the aircraft electrical circuits are de-energized.
A. At the end of the flight, do a check of the residual ground speed related to the IR1 on the CAPT ND.
4. Fault Isolation- To read the residual ground speed related to the IR3:
. Set the ATT HDG selector switch to CAPT/3.
NOTE: The radial position error does not stay in the memory of the MCDU after the aircraft electrical circuits are de-energized.
Subtask 34-14-00-810-181-A
A. Compare the ground speed values that you read with these limits:
(1) If the residual ground speed value is lower than or equal to 14 kts, no maintenance action is necessary.
(2) If the residual ground speed value is equal to or greater than 21 kts, replace the ADIRU1 or ADIRU3 AMM 34-12-34-000-001 and AMM 34-12-34-400-001.
(3) If the residual ground speed is between 15 and 20 kts, you must do a check of this value after the subsequent flight:
(a) If after the second check, the residual ground speed is lower than or equal to 14 kts, no maintenance action is necessary.
(b) If after the second check, the residual ground speed is 15 kts or more, replace the ADIRU1 or ADIRU3 AMM 34-12-34-000-001 and AMM 34-12-34-400-001.
(1) If the residual ground speed value is lower than or equal to 14 kts, no maintenance action is necessary.
(2) If the residual ground speed value is equal to or greater than 21 kts, replace the ADIRU1 or ADIRU3 AMM 34-12-34-000-001 and AMM 34-12-34-400-001.
(3) If the residual ground speed is between 15 and 20 kts, you must do a check of this value after the subsequent flight:
(a) If after the second check, the residual ground speed is lower than or equal to 14 kts, no maintenance action is necessary.
(b) If after the second check, the residual ground speed is 15 kts or more, replace the ADIRU1 or ADIRU3 AMM 34-12-34-000-001 and AMM 34-12-34-400-001.