W DOC AIRBUS | TSM A320F

GPS PRIMARY LOST displayed on the NAV DISPLAY

TASK 34-58-00-810-828-A
GPS PRIMARY LOST displayed on the NAV DISPLAY

1. Possible Causes

2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 34-14-00-810-926-A
Disagree between the FMS and the IRS Positions/Excessive drift
AMM 34-12-34-200-001
ADIRU Removal Criteria
AMM 34-36-00-710-002
Operational Test of the GPS
3. Fault Confirmation
Subtask 34-58-00-700-050-A
A. Test
  • Not applicable, no confirmation test is necessary.
4. Fault Isolation
Subtask 34-58-00-810-077-B
A. Do a check for a maintenance message on the POST FLIGHT REPORT (PFR).
   (1) If there is no maintenance message:
  • On the MCDU, on the "SELECTED NAVAIDS" page, make sure that the GPS SELECTED indication is shown.
     (a) If the indication is not shown:
  • On the MCDU, change the status from DESELECTED to SELECTED.
     (b) If the indication is shown:
  • Go to step B.
   (2) If there is a maintenance message:
  • Do the trouble shooting procedures related to the maintenance messages.
NOTE: Some operational warnings are not printed on the PFR.
Subtask 34-58-00-810-081-B
B. On the MCDU, on the "GPS POSITION MONITOR" page, make sure that the GPS position is available.
   (1) If no GPS position is available:
  • Move the aircraft to an area where the GPS signal may be acquired.
     (a) If the signal is not acquired:
     (b) If the signal is acquired:
  • Go to step C.
   (2) If at least one GPS position is available:
  • Go to step C.
Subtask 34-58-00-810-082-A
C. Compare the IR drift with the values given in the AMM task AMM 34-12-34-200-001.
   (1) If the values are not correct:
   (2) If the values are correct:
  • No maintenance action is necessary.
[Rev.8 from Aug 2018] 2026.04.04 04:33:34 UTC
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