Message Name:

L WTC FAIL WSHLD CH W/O REGUL

Message Code:

3040001IN

Associated CAS:

L WSHLD HEAT FAIL
(Caution)

An internal failure has been detected in the Left Windshield Temperature Controller (L-WTC), accompanied by loss of heating to the left windshield.

• Left Windshield Temperature Controller (WTC) (A164)
• Left Windshield (HR9)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-30-0463 - No Fault Found (NFF) initiative - Windshield Temperature Controller (WTC)
• Windshield Troubleshooting Report to help with windshield temperature controller NFF

Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None

Flight Operation Notifications Manual (FONM): None

1. Remove all connectors from the left WTC. Inspect connectors and pins for damage/defects.

   1. If defects or damage is found, repair/rectify as required and do close out.
   2. If no defects or damage is found, reconnect the WTC connectors and continue with next step.

2. Perform ground Functional Test.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

3. Interchange the left WTC with the right WTC

   1. If confirmed faulty, replace defective WTC and do close out.
   2. If fault still present on same side, continue with next step.

4. Carry out a resistance check of the windshield Heater.
   Measure the Heater resistance between T1 and T2. The total resistance of the anti-fog coating when measured between terminal blocks shall be 11.73 Ω - 15.87 Ω (at 19°C - 29°C).

   1. If resistance within range, continue with next step.
   2. If resistance out of range, replace affected windshield and do close out.

5. Measure the temperature sensor resistance between S1 and S2 (refer to Windshield and Side Window Temperature Sensor Resistance Chart).

   1. If resistance within range, go to step 7.
   2. If resistance out of range, continue with next step.

6. Connect spare temperature sensor on left windshield (HR9/ S2).
7. Do close out.