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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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For AOG assistance contact:

CRC Montreal (YUL)
Quick Links

04/26/21

Message Overview:

Message Name:

RADIO ALTIMETER FLAG (Warning)

Identifier: 344OBS001
Effectivity: AIRCRAFT 20501 - 20999
System: Navigation
Associated CAS: None
System Description: 34-44-00
Schematic Diagram: None
Wiring Diagram: 34-44-01

Message Description:

The red 'RA' warning flag indicates the radio altimeter indication is inoperative.

  • A loss of all radio altimeter information to the PFD from the radio altimeter, most likely caused by the radio altimeter receiver/transmitter.

Possible Causes:

  • Radio Altimeter Receiver/Transmitter (RAD ALT) (A32)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: A metallic or reflective surface (Water, Ice, metal plates, metal grills, etc...) underneath the RA antennas when aircraft is on the ground can cause erratic readings and cause the unit to fail. The first thing that should be attempted is move the A/C a few feet and test the system again.

Quick Links:

Operational Test of the Radio Altimeter System AMM 34-44-00-710-801
Removal of the Radio Altimeter Transceiver AMM 34-44-01-000-801
Installation of the Radio Altimeter Transceiver AMM 34-44-01-400-801
Removal of the Radio Altimeter Antenna AMM 34-44-09-000-801
Installation of the Radio Altimeter Antenna AMM 34-44-09-400-801
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. Troubleshooting using the MDC current fault page may help isolate the system, verify that power is available and check the data bus information.
  2. Interrogate the MDC as follows:

    1. 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.
    2. 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 fault. Going into advanced diagnostics will provide an equation id for the fault identified.
    3. Select the MDC fault or equation from the drop down below to provide additional information to assist in troubleshooting.

  3. If no MDC Fault Codes/Message are present, replace Radio Altimeter Transceiver (RAD ALT) (A32).
  4. Do close out.

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