Terrain Failure Alert; Terrain Not Available' Alert - Garmin 400 Series Pilot's Manual Addendum

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' (Figure 3-5).

'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, if the terrain/obstacle database is not
available, or if the aircraft is out of the database coverage area, the annunciation 'TERRAIN NOT
AVAILABLE' is displayed on the TERRAIN Page (Figure 3-6).
Section 3
TERRAIN Alerts
Figure 3-5: 'TERRAIN has failed' message
Figure 3-6: 'TERRAIN NOT AVAILABLE' display
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