Failure of the Pitot Probe (PHC1)

TASK 30-31-00-810-802-A
Failure of the Pitot Probe (PHC1)

1. Possible Causes

PROBE-PITOT, 1 [9DA1]
PHC-1 [6DA1]
wiring from the PHC 1 (6DA1) to the pitot probe 1 (9DA1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 30-31-00-710-001	Operational Test of the Probe Ice Protection
ASM 303101
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 34-11-15-000-001	Removal of the Pitot Probe
AMM 34-11-15-400-001	Installation of the Pitot Probe

3. Fault Confirmation
Subtask 30-31-00-710-052-A

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

4. Fault Isolation
Subtask 30-31-00-810-051-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message PITOT PROBE 9DA1:

Disconnect the connector from the pitot probe 1 (9DA1) and do a check of the resistance between pins A/B and A/C.

(1) If the resistance is more than 35,7 ohms (open circuit) or less than 32,3 ohms (short circuit) at a temperature of 20 deg.C (68 deg.F):
(a) Replace the PROBE-PITOT, 1 [9DA1] , AMM 34-11-15-000-001 and AMM 34-11-15-400-001.
(2) If the resistance is between 32,3 ohms and 35,7 ohms at a temperature of 20 deg.C (68 deg.F):
(a) Replace the PHC-1 [6DA1] , AMM 30-31-34-000-002 and AMM 30-31-34-400-002.
(b) If the fault continues:

Do a check and repair the wiring from the PHC 1 (6DA1) to the pitot probe 1 (9DA1), pin A/H to pin A/B ASM 303101.

Subtask 30-31-00-810-051-D ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message PITOT PROBE 9DA1:

Disconnect the connector from the pitot probe 1 (9DA1) and do a check of the resistance between pins A/B and A/C.

(1) If the resistance is more than 34 ohms (open circuit) or less than 24 ohms (short circuit) at a temperature of 20 deg.C (68 deg.F):
(a) Replace the PROBE-PITOT, 1 [9DA1] , AMM 34-11-15-000-001 and AMM 34-11-15-400-001.
(2) If the resistance is between 24 ohms and 34 ohms at a temperature of 20 deg.C (68 deg.F):
(a) Replace the PHC-1 [6DA1] , AMM 30-31-34-000-002 and AMM 30-31-34-400-002.
(b) If the fault continues:

Do a check and repair the wiring from the PHC 1 (6DA1) to the pitot probe 1 (9DA1), pin A/H to pin A/B ASM 303101.

Subtask 30-31-00-710-053-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:29:34 UTC