Message Name:

PITOT-STATIC2 HEATER / WRG

Message Code:

3031104HBM

Associated CAS:

PITOT 2 HT FAIL
(Caution)

The PITOT-STATIC2 Probe Heater(s) circuit has been detected opened by Heater/Brake Temperature Monitor Unit (HBMU) 2.

• Pitot/Static Probe 2 Heater (MT152)
• Heater/Brake Temperature Monitor Unit (HMBU) 2 (A93)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-45-0065 - CAIMS Nuisance Fault Messages

Forum Articles/Infoservice/Newsletter: None

Notice To Operators (NTO): None

Flight Operation Notifications Manual (FONM): None

1. Perform wiring checks between HBMU2 (A93P1) and Pitot Static Probe 2 Heater (MT152P1). Repair as required.
   

   HBMU2 to Pitot/Static Probe 2

   From:	To:	Expected Result:	Actual Result:
   HBMU 2 A93P1-K	Pitot/Static Probe 2 MT152P1-1	0 Ω
   Chassis Ground	Pitot/Static Probe 2 MT152P1-2	0 Ω

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

2. Measure the resistance of Pitot Static Probe 2 Heater.
   

   Pitot/Static Probe 2 Head & Base Heaters

   From:	To:	Expected Result:	Actual Result:
   Pitot/Static Probe 2 Head Heater MT152P1-1	Pitot/Static Probe 2 Head Heater MT152P1-2	20 Ω ±10 Ω @ 68°F [20°C]
   Pitot/Static Probe 2 Base Heater MT152P2-1	Pitot/Static Probe 2 Base Heater MT152P2-2	≈ 210 Ω @ 68°F [20°C]

   PS2 probe head heater should be 20 Ω ±10 Ω at 68°F [20°C]
   PS2 probe base heater should be 210 Ω approximately

   1. If resistance within range, go to step 4.
   2. If resistance out of range, continue with next step.

3. Replace Pitot Static Probe 2.

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

4. Interchange HBMUs. Replace if necessary.
5. Do close out.