R BLEED FAIL
(Caution)

The amber 'R BLEED FAIL' caution CAS message indicates the intermediate pressure valve has failed, (Flow Control Valve).

• The IACS has detected the FCV is failed in the closed position, failed in the open position, or a drift in pressure control settings (pressure is controlled too high, or too low). IASC1 controls the FCV1, IASC2 controls the FCV2.
• If the bleed pressure is above 60 psi, the fail message is posted and the affected bleed pressure display turns amber.

Advisory Wire/Service Bulletin:

• AW300-30-0354 - Potential Piccolo Tube Damage When Replacing a Bleed Loop Element

Forum Articles/Infoservice/Newsletter: None

NOTE: If fault is intermittent or can not be duplicated on the ground, download IASC NVM along with MDC Flight History file and the Service Message History file and send to the CRC.

1. Check the current faults and fault history for problems related to the IASC controller and pressurization system. Under advance diagnostics, look for the following faults and equations:
2. On the cursor control panel, ensure the toggle switch is to the right and select Anti-Ice, ECS and Fuel buttons simultaneously. The MDC main menu should now be displayed on Display Unit #3.
3. Using the joystick, select Current Faults (if the fault is active) or Aircraft History to research stored faults. From Aircraft History you can then select Fault Message History and locate the air condition fault logged.
4. Select the MDC fault from the drop down below to provide additional information to assist in troubleshooting.

   1. If a B3 Fault Code is displayed: Select an MDC Fault Code/Message:B3-006660 - NO SIGNAL/OUT OF RANGE [DIFF PRESS SNSR1]B3-006661 - NO SIGNAL/OUT OF RANGE [DIFF PRESS SNSR2]B3-006825 - CH A&B FAULT [HOT AIR T SNSR]B3-007403 - CH A&B FAULT [PK INLET T SNSR]B3-006388 - DISAGREE / VALVE OPEN [BLEED VALVE 1]B3-006389 - DISAGREE / VALVE CLOSED [BLEED VALVE 1]B3-006394 - DISAGREE / VALVE CLOSED [BLEED VALVE 2]B3-006395 - DISAGREE / VALVE OPEN [BLEED VALVE 2]B3-006396 - R BLEED PRESSURE HIGH [BLEED VALVE 2]B3-006397 - R BLEED PRESSURE LOW [BLEED VALVE 2]
   2. If no fault codes are displayed, continue with next step.
      
      

5. When the IASC sees No Flow when it is demanded, it drives the FCV to the Full Open position. This can cause a PACK INLET OVERHEAT and R BLEED FAULT CAS messages with no MDC Fault Code.
6. Run both engines at idle and monitor / record the bleed pressure parameters from the MDC.
7. The Differential Pressure reading should be around 0.8 psid at idle and should react to engine thrust increase.

   1. If you notice that it is stuck at 0.0 psid and does not react to thrust increase, that Differential Pressure Sensor is to be suspected.
      

      	Left Engine (GOOD)	Right Engine (BAD)
      Bleed Pressure:	49 psi	51 psi
      Differential Pressure:	0.8 psid	0.0 psid
      BAF:	9.5 lb/min	0.0 lb/min

      NOTE: If the Differential Pressure Sensor is stuck at 0 psid, it could cause the FCV to stay in the FULL OPEN position.

   2. If pressures and Differential are good, continue with next step.

8. Perform a wiring check of the R BLEED (SDS14) PBA on the AIR CONDITIONING / BLEED CONTROL PANEL (PL17).

   1. If PBA is found defective, replace as required.
   2. If no defects are found, continue with next step.

9. Perform a wiring check between the R BLEED (SDS14) PBA on the AIR CONDITIONING / BLEED CONTROL PANEL (PL17), IASC 2 (A56), the Data Concentrator Unit (DCU) (A14) and the R BLEED VALVE (V4).

   1. If wiring defects are found, repair defective wiring as required and do close out.
   2. If no defects are found, continue with next step.

10. Swap IASC 2 with IASC 1. Is the fault still present?

    1. If YES, continue with next step.
    2. If NO, replace faulty IASC.

11. Swap the right Bleed Valve with the left bleed valve to confirm faulty valve and replace if required.
12. Do close out.