background
x
loader
Troubleshooting
arrow By ATA By Message Color By Observed Faults by MDCBy Tips

Select color for CAS message that you wish to troubleshoot

(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

This page includes :

For AOG assistance contact:

CRC Montreal (YUL)
Quick Links

02/26/21

Message Overview:

Message Name:

POSITION SENSOR FAULT

Message Code:

B3-007120

Associated CAS:

FLAPS FAIL
(Caution)

Reporting LRU: L POSITION SNSR
System Description: 27-52-00
Schematic Diagram: 27-52-00
Wiring Diagram: 27-52-45

Message Description:

The Flap Control Unit is reporting a failure with the Left Flap Position Sensor.

Possible Causes:

  • Left Flap Position Sensor (MPE77)
  • Flap Control Unit (FCU) (A124)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin:

  • AW300-27-0058 - Flap Control Unit - CAS Messages Reset procedure (20501 to 20999)

Forum Articles/Infoservice/Newsletter: None

If Flap Control Unit (FCU) PN: 2257A0000-02 is installed, the reset procedure included in AW300-27-0058 may clear the fault.

Quick Links:

Removal of the Flap Control Unit (FCU) AMM 27-51-05-000-801
Installation of the Flap Control Unit (FCU) AMM 27-51-05-400-801
Operational Test of the Flap Control Unit (FCU) AMM 27-51-05-710-801
Electrical Rigging of the Flap System AMM 27-52-00-820-801
Removal of the Flap Position Sensor AMM 27-52-17-000-802
Installation of the Flap Position Sensor AMM 27-52-17-400-802
Wiring - Maintenance Practices - ALL SPM 20-12-00-02
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02
Electrical Connectors - Maintenance Practice - ALL SPM 20-20-00-02

Troubleshooting Recommendations:

  1. Reset the following circuit breakers.

    FLAP R IND CB2-B12
    FLAP L IND CB1-B13
    FLAP CTRL CB1-B14

  2. Reset the FCU by pressing the FCU reset button on the MAINTENANCE TEST control-panel.

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

  3. Do the Electrical Rigging of the Flap system.

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

  4. Do wiring check between FCU connectors A124AP1/ A124BP1 and Left Flap Position Sensor connectors A77AP1/A77BP1. Repair/replace as required.

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

  5. Check internal wiring integrity of Left Flap Position Sensor as per the following table.

    1. If wiring is confirmed good, go to step 7.
    2. If wiring is found defective, continue with next step.

    Channel A Channel B
    MPE77P1 Value MPE77P2 Value
    Between pin 1 and pin 2 110Ω Between pin 1 and pin 2 110Ω
    Between pin 3 and pin 4 75Ω Between pin 3 and pin 4 75Ω
    Between pin 5 and pin 6 75Ω Between pin 5 and pin 6 75Ω

    NOTE: A swap of both Flap Position Sensors can also be done to confirm a defective Flap Position Sensor.

  6. Replace Left Flap Position Sensor.

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

  7. Replace FCU.
  8. Do close out.

Registered and/or unregistered trademarks of Bombardier Inc. or its subsidiaries. © 2015 Bombardier Inc. All rights reserved.