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(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.

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Quick Links

07/09/19

Message Overview:

Fault Message:

AIR DATA CMPTR #1/ BUS #1 FAULT

Fault Code:

27660291SX

Associated CAS:

MACH TRIM FAIL
(Caution)

RUD AUTHORITY HIGH
(Caution)

RUD AUTHORITY LOW
(Caution)

RUD LIMITER FAIL
(Caution)

PITCH FEEL FAULT
(Advisory)

RUD AUTHORITY SAFE
(Advisory)

SPLRS STAB IN TEST
(Advisory)

Reporting LRU: Flight Control Unit (FCU) 1
System Description: 27-60-00
Schematic Diagram: 27-60-00 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wiring Diagram: 27-60-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]
34-11-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Fault Description:

Flight Control Unit (FCU) 1 does not receive data from Micro Air Data Computer (MADC) 1.

Possible Causes:

  • Micro Air Data Computer (MADC) 1 (A27)
  • Ground Proximity Warning System (GPWS) (A64)
  • Junction Box (JB3)
  • Flight Control Unit (FCU) 1 (A65)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin:

Forum Articles/Infoservice/Newsletter: None

NOTE: No action required, if it is reported in the fault history only.

This fault may sometime be cleared by performing the flight control system reset procedure.

The status of the MADC#1 can be found in CAIMS:

  1. SYSTEM DIAG
  2. 27-00 FLIGHT CONTROLS
  3. FLIGHT CONTROL UNIT #1
  4. LRU TEST
  5. DISPLAY MISC. & SENSORS STATUS
  6. Go to page 3 of 3

Quick Links:

Removal of the Junction Box JB3 AMM 24-00-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Junction Box JB3 AMM 24-00-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Junction Box JB3 Circuit-Cards AMM 24-00-02-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Junction Box JB3 Circuit-Cards AMM 24-00-02-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Flight-Control Units AMM 27-61-05-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Flight-Control Units AMM 27-61-05-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Micro Air-Data Computers AMM 34-11-09-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Micro Air-Data Computers AMM 34-11-09-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Enhanced Ground-Proximity Warning
System (EGPWS) Computer		 AMM 34-42-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Enhanced Ground-Proximity Warning
System (EGPWS) Computer		 AMM 34-42-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
CAIMS PMAT General Instructions AMM 45-45-00-970-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Access to Active Faults AMM 45-45-00-970-802 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Electronic Junction Box CMM 24-00-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

  1. If the CAS message ADC 1 FAIL is posted, troubleshoot it first.
  2. Measure for 4.4 VDC or higher at JB3 test points for ARINC 429 Bus.

    1. If voltage is not present, go to step 7.
    2. If voltage is present, continue with next step.

      ARINC 429 Bus For 93 pins Test point Connector
      (JB3 PCB5 P/N 00514-0069-0002)      		 JB3 (JB3CP1) FCU 1 (A65DP1) MADC 1 (A27P1) GPWS (A64BP1)
      High TP - 64 JB3CP1-7F,JB3CP1-7H, JB3CP1-7K, JB3CP1-8B and JB3CP1-8D A65DP1-8K A27P1-60 A64BP1-A11
      Low TP - 63 JB3CP1-7G, JB3CP1-7J, JB3CP1-8A, JB3CP1-8C and JB3CP1-8E A65DP1-8J A27P1-61 A64BP1-B11
      ARINC 429 Bus For 96 pins Test point Connector
      (JB3 PCB5 P/N 00514-0069-0001)      		 JB3 (JB3CP1) FCU 1 (A65DP1) MADC 1 (A27P1) GPWS (A64BP1)
      High TP - 66 JB3CP1-7F,JB3CP1-7H, JB3CP1-7K, JB3CP1-8B and JB3CP1-8D A65DP1-8K A27P1-60 A64BP1-A11
      Low TP - 65 JB3CP1-7G, JB3CP1-7J, JB3CP1-8A, JB3CP1-8C and JB3CP1-8E A65DP1-8J A27P1-61 A64BP1-B11

      NOTE: The test point’s references inside the junction boxes in the wiring diagram are not accurate. (Reference CMM24-00-01)
      NOTE: Pin to pin and pin to ground wiring check can be done through the JB test point. DO NOT perform an insulation test through the junction box.

  3. Measure for 4.4 VDC at FCU 1 for ARINC 429 Bus.

    1. If voltage is present, go to step 9.
    2. If voltage is not present, continue with next step.

  4. Perform wiring checks between FCU 1 and JB3 test points.

    1. If wiring checks are not good, repair defective wiring as required and do close out.
    2. If wiring checks are good, continue with next step.

  5. Replace JB3 Circuit Board 5 (JB3 PCB5).

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

  6. Replace JB3 and do close out.

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

  7. Measure for 4.4 VDC or higher at GPWS for ARINC 429 Bus.

    1. If voltage is present, go to step 5.
    2. If voltage is not present, continue with next step.

  8. Measure for short circuit for shorted to ground, shorted to shield, and shorted between wires of ARINC 429 Bus.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.
      NOTE: Remove GPWS, MADC 1, FCU 1 and Engine Firewall connector (1PA2) for this test.

  9. Swap FCU 1 with FCU 2.

    1. If system checks are good, replace FCU 1. Reset FCUs latched faults and do close out.
    2. If fault remains, continue with next step.

  10. Swap MADCs.

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

  11. Perform wiring checks between MADC 1 and JB3 test points for ARINC 429 Bus.

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

  12. Replace GPWS.
  13. Do close out.

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