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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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06/30/21

Message Overview:

Message Name:

EMERGENCY LIGHT - OVERWING EXIT LIGHTS UNSERVICEABLE

Message Code: 335OBS001
Effectivity: All
System: Emergency Lighting System
System Description: 33-50-00
Schematic Diagram: 33-51-00 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wiring Diagram: 33-51-03 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Message Description:

The Exterior Emergency Overwing Exit Lights are not illuminating.

NOTE: The troubleshooting is different depending if the FWD or AFT Light is not illuminating.

Possible Causes:

  • Emergency Lighting Power Supply (ELPS) 3 (A158)
  • Emergency Lighting Power Supply (ELPS) 4 (A160)
  • Emergency Lighting Power Supply (ELPS) Battery
  • Emergency Light Bulb
  • Overwing Emergency Exit Light (DS26)
  • Overwing Emergency Exit Light (DS27)
  • Light Assembly
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: For instructions on how to use CAIMS to determine if a power supply is faulty, refer to EMER LIGHTS OFF or EMER LIGHTS ON.

Quick Links:

Removal of the Over-Wing Emergency-Exit Lights AMM 33-51-05-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Over-Wing Emergency-Exit Lights AMM 33-51-05-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Replacement of the Over-Wing Emergency-Exit Light-Bulb AMM 33-51-05-960-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Emergency Lighting Power Supplies (ELPS) AMM 33-51-09-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Emergency Lighting Power Supplies (ELPS) AMM 33-51-09-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Replacement of the Internal Battery of the Emergency Lighting
Power Supplies (ELPS)		 AMM 33-51-09-960-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Functional Test of the Emergency Lights Power-Supplies AMM 33-51-09-720-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

CAUTION: DO NOT OPERATE THE INTERNAL AND EXTERNAL LIGHTING FOR MORE THAN 10 MINUTES. CONTINUED OPERATION WILL DECREASE THE CHARGE OF THE BATTERIES OF THE EMERGENCY LIGHTING POWER-SUPPLIES.

  1. Check which Overwing Emer light is not illuminating.

    1. If the AFT Overwing Emer light is not illuminating, go to step 11.
    2. If the FWD Overwing Emer light is not illuminating, continue with next step.

  2. Are there any lights other than the FWD overwing Emer light not illuminating?

    1. If YES, ELPS 3 battery may be discharged. Perform AMM Task 33-51-09-720-801 and continue with next step.
    2. If NO, go to step 6.

  3. Does the FWD Overwing light illuminate?

    1. If YES, go to step 7.
    2. If NO, continue with next step.

  4. Does ELPS 3 hold its electrical charge?

    1. If NO, replace ELPS 3's battery and do close out.
    2. If YES, continue with next step.

  5. Check the ELPS status in CAIMS, using the troubleshooting steps contained in EMER LIGHTS OFF or EMER LIGHTS ON CAS message tasks.
  6. Check if only the FWD overwing emergency light is not illuminating, inspect the Emergency light bulb. Is the Light bulb in good working condition?

    1. If NO, replace the light bulb and do close out.
    2. If YES, continue with next step.

  7. In the flight compartment, on the PASS SIGNS/EMER LIGHTS control panel (AP13), set the EMER LIGHTS switch to ON.
  8. Perform a voltage check as follows:

    FWD Overwing
    Emer light    		 Expected Result
    DS27-1 6 VDC

    1. If there is 6 VDC, replace the light assembly and do close out.
    2. If there is no 6 VDC, continue with next step.

  9. In the flight compartment, on the PASS SIGNS/EMER LIGHTS control panel (AP13), set the EMER LIGHTS switch to OFF.
  10. Perform a continuity check between ELPS 3 and the Emergency light as follows:

    From To Result
    A158P1-G DS27-1
    A158P1-D Ground
    DS27-2 Ground

    1. If there is no continuity, repair defective wiring as required and do close out.
    2. If there is continuity, replace ELPS 3 and do close out.

  11. Are there any lights other than the AFT overwing Emer light not illuminating?

    1. If YES, ELPS 4 battery may be discharged. Perform AMM Task 33-51-09-720-801 and continue with next step.
    2. If NO, go to step 15.

  12. Does the AFT Overwing light illuminate?

    1. If YES, go to step 16.
    2. If NO, continue with next step.

  13. Does ELPS 4 hold its electrical charge?

    1. If NO, replace ELPS 4's battery and do close out.
    2. If YES, continue with next step.

  14. Check the ELPS status in CAIMS, using the troubleshooting steps contained in EMER LIGHTS OFF or EMER LIGHTS ON CAS message tasks.
  15. Check if only the AFT overwing emergency light is not illuminating, inspect the Emergency light bulb. Is the Light bulb in good working condition?

    1. If NO, replace the light bulb and do close out.
    2. If YES, continue with next step.

  16. In the flight compartment, on the PASS SIGNS/EMER LIGHTS control panel (AP13), set the EMER LIGHTS switch to ON.
  17. Perform a voltage check as follows:

    AFT Overwing
    Emer light    		 Expected Result
    DS26-1 6 VDC

    1. If there is 6 VDC, replace the light assembly and do close out.
    2. If there is no 6 VDC, continue with next step.

  18. In the flight compartment, on the PASS SIGNS/EMER LIGHTS control panel (AP13), set the EMER LIGHTS switch to OFF.
  19. Perform a continuity check between ELPS 4 and the Emergency light as follows:

    From To Result
    A160P1-G DS26-1
    A160P1-D Ground
    DS26-2 Ground

    1. If there is no continuity, repair defective wiring as required and do close out.
    2. If there is continuity, continue with next step.

  20. Replace ELPS 4.
  21. Do close out.

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