• EGPWS Terrain Position (TERR POS) Message: Notes:
  • The amber TERR POS message indicates a horizontal position calculation failure of the enhanced portion of the Ground Proximity Warning Computer
  
  
  • Basically the look-ahead terrain alerting and display is unavailable due to position uncertainty.
  
  
  • This message will show if the airplane’s GPS antennas do not have a clear view of the GPS satellites.
  
  
  
  
  (TERR POS) Message Possible Causes:

  Before replacing any component perform BITE if available. (Push the test switch once for level 1 test, twice for current faults.) Also Bite the MMR.

  
  

  1.Ground Proximity Warning Computer

  
  

  2.Wiring
  
  

  3.Dual MMR GPS function failure
  
  EGPWS Terrain Fail:

  

  
  

  

  
  

  

  
  

  

  
  Circuit Breakers:

  GND PROX Warn: P18-1 = B7.

  MMR#1/ILS#1: P18-1 = A2.

  MMR#2/ILS#2: P6-1 = A13.

  
  
  Applicable deferrals MEL 34-26-08 Forward Looking Terrain Avoidance function
  MEL 34-26-09 Terrain Display functions

Training Only