ADS-B FAIL
(Advisory)

Transponder has failed or has no GPS no data available.

• Air Traffic Controller (ATC) Transponder in VHF COM Unit 1 (A1)
• Air Traffic Controller (ATC) Transponder in VHF COM Unit 2 (A2)
• Global Positioning System (GPS) (A19)
• Global Positioning System (GPS) (A212)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-34-0516 - Space Based Augmentation System (SBAS) Global Navigation Satellite Sensor Unit (GNSSU) failure in flight

Forum Articles/Infoservice/Newsletter:

• Forum - Volume 18. Issue 02 (January 28, 2021) - Global navigation satellite system: interference, signal loss and jamming

Flight Operation Notifications Manual (FONM):

• [ Global Express ]  [ G5000 ]  [ Global XRS ] FON 01-05 - AVNC-030-A - GNSS Outage due to Signal Degradation or Jamming with Associated FDE

NOTE: ADS-B FAIL may be displayed on power up until GPS acquires satellite data.

1. Make sure GPS units are powered up and are providing position to A/C.
2. On the Radio Management Unit (RMU), while the fault is still displayed, switch to the cross side ATC. If the fault is no longer displayed, it will indicate if the fault is related to system 1 or system 2.
3. Check CAIMS Active faults. If there are any faults related to GPS 1, GPS 2, VHF COM Unit 1 or VHF COM Unit 2, troubleshoot them first.
4. Swap VHF COM Unit 1 with VHF COM Unit 2. Is the fault still present?

   1. If YES, continue with next step.
   2. If NO, replace defective VHF COM Unit.

5. Swap GPS Unit 1 with GPS Unit 2. Is the fault still present?

   1. If YES, continue with next step.
   2. If NO, replace defective GPS Unit.

6. Disconnect GPS 1 connector A19P1 and access VHF COM Unit 1 connector A1P1. Do a continuity check as follows:
   

   From	To	Result
   A19P1-38	Ground
   A19P1-39	Ground

   1. If there is continuity, repair defective wiring as required.
   2. If there is NO continuity continue with next step.

7. Do a continuity check as follows:
   

   From	To	Result
   A19P1-38	A1P1-98
   A19P1-39	A1P1-85

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

8. Disconnect GPS 2 connector A212P1 and access VHF COM Unit 2 connector A2P1. Do a continuity check as follows:
   

   From	To	Result
   A212P1-38	Ground
   A212P1-39	Ground

   1. If there is continuity, repair defective wiring as required.
   2. If there is NO continuity continue with next step.

9. Do a continuity check as follows:
   

   From	To	Result
   A212P1-38	A2P1-98
   A212P1-39	A2P1-85

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

10. Verify the interface between the ATC antennas and the affected VHF COM Unit. Repair as required.
11. Do close out.