Loss of the GND/FLT Information (PHC 3)

TASK 30-31-00-810-825-A
Loss of the GND/FLT Information (PHC 3)

1. Possible Causes

PROX SNSR-NLG EXT, SYS 1 [24GA]
PROX SNSR-NLG EXT, SYS 2 [25GA]
LGCIU-1 [5GA1]
C/B-L/G/LGCIU/SYS1/NORM [1GA]
C/B-HYDRAULIC/LGCIU/SYS2 [2GA]
C/B-HYDRAULIC/LGCIU/SYS1/GRND SPLY [52GA]
PHC-3 [6DA3]
LGCIU-2 [5GA2]
wiring
ADIRU-3 [1FP3]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 30-31-00-710-001	Operational Test of the Probe Ice Protection
ASM 303103
AMM 30-31-34-000-002	Removal of the Probe Heat Computer (PHC)
AMM 30-31-34-400-002	Installation of the Probe Heat Computer (PHC)
AMM 32-00-00-860-001	Flight Configuration Precautions with Electrical Power
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
AMM 32-31-73-000-005	Removal of the NLG Proximity-Sensors
AMM 32-31-73-200-002	Inspection of the NLG Proximity Sensor and Target Clearances
AMM 32-31-73-400-005	Installation of the NLG Proximity-Sensors
AMM 34-12-34-000-001	Removal of the ADIRU
AMM 34-12-34-400-001	Installation of the ADIRU

3. Fault Confirmation
Subtask 30-31-00-710-098-A

A. Test
(1) Do the operational test of the probe ice protection AMM 30-31-00-710-001.

4. Fault Isolation
Subtask 30-31-00-810-074-A

A. If the ECAM warning message ANTI ICE STBY PITOT comes into view only or associated with the maintenance message CHECK LGCIU - PHC 3 INTERFACE and if the loss of the GND/FLT information occurred:

make sure that there is no maintenance message related to the landing gear system (Ref. ATA 32).

(1) If there is one or more maintenance message(s):

do the related trouble shooting.

(2) If there is no maintenance message:

do the inspection of the NLG proximity sensor and target clearances AMM 32-31-73-200-002.

(a) If the fault continues:

replace the PROX SNSR-NLG EXT, SYS 1 [24GA] and PROX SNSR-NLG EXT, SYS 2 [25GA] , AMM 32-31-73-000-005 and AMM 32-31-73-400-005.

(b) If the fault continues:

do a check for ground at pin A/E and/or pin A/D and/or pin A/I of the PHC3 (6DA3).

1 If there is no ground signal:

replace the LGCIU-1 [5GA1] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.

2 If there is a ground signal:
Simulate the flight configuration:

on the panel 49VU, open the C/B-L/G/LGCIU/SYS1/NORM [1GA] circuit breaker
on the panel 121VU, open the C/B-HYDRAULIC/LGCIU/SYS2 [2GA] and C/B-HYDRAULIC/LGCIU/SYS1/GRND SPLY [52GA] circuit breakers.

NOTE: Make sure that you obey the flight configuration precautions AMM 32-00-00-860-001.

Do a check for ground at PIN A/E and/or PIN A/D and/or A/I of the PHC-3 (6DA3).

a If there is a ground signal:

replace the LGCIU-1 (5GA1), AMM 32-31-71-000-001 and AMM 32-31-71-400-001.

b If there is no ground signal:

replace the PHC-3 [6DA3] , AMM 30-31-34-000-002 and AMM 30-31-34-400-002.

c If the fault continues:

replace the LGCIU-2 [5GA2] .
* If the fault continues:
do a check and repair the wiring from the PHC 3 pin A/E to the LGCIU 1 pin AB/15A, and/or from the PHC 3 pin A/D to the LGCIU 2 pin AB/15A ASM 303103.

d If the fault continues:

replace the ADIRU-3 [1FP3] AMM 34-12-34-000-001 and AMM 34-12-34-400-001.

Subtask 30-31-00-710-099-A

B. Do the operational test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:29:36 UTC