2 - NAV PAGES
50
190-00357-00 Rev H
TERRAIN Failure Alert
The TERRAIN system continually monitors
several system-critical items, such as database validity,
hardware status, and GPS status. Should the system
detect a failure, a message is annunciated “TERRAIN
has failed”.
“TERRAIN has failed” message
“TERRAIN Not Available” Alert
The TERRAIN system requires a 3D GPS
navigation solution along with specific vertical
accuracy minimums. Should the navigation solution
become degraded, or if the aircraft is out of the
database coverage area, the annunciation “TERRAIN
NOT AVAILABLE” is displayed on the TERRAIN Page.
“TERRAIN NOT AVAILABLE” display
Terrain Alerts
700
600
500
400
300
200
100
Height Above Terrain (Feet)
Distance From Destination Airport (nm)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
PDA Alerting AreaPDA Alerting Area
Runway
Threshold
Premature Descent Alerting (PDA) Threshold
