Section 10: Terrain; Introduction - Garmin GNC 420(A) Pilot's Manual & Reference

SECTION 10: TERRAIN

NOTe: Not all GNC 420 units are equipped with
or configured for TerraiN. See the 400-series
installation Manual (190-00140-02) for TerraiN
configuration information.

10.1 INTRODUCTION

Garmin TERRAIN is a non-TSO-C151b-certified
terrain awareness system incorporated into GNC 420
units to increase situational awareness and aid in
reducing controlled flight into terrain (CFIT). TERRAIN
functionality is a standard feature found in GNC 420 units
with main software version 5.01 or above, along with
appropriate hardware upgrades.
Operating Criteria
TERRAIN requires the following to operate properly:
• The system must have a valid 3-D GPS position
solution.
• The system must have a valid terrain/obstacle/
airport terrain database.
190-00140-20 Rev. K
Limitations
TERRAIN displays terrain and obstructions relative
to the altitude of the aircraft. The displayed alerts are
advisory in nature only. Individual obstructions may
be shown if available in the database. However, all
obstructions may not be available in the database and
data may be inaccurate. Never use this information for
navigation or to maneuver to avoid obstacles.
Terrain information is based on terrain elevation
information in a database that may contain inaccuracies.
Terrain information should be used as an aid to situational
awareness. Never use it for navigation or to maneuver to
avoid terrain.
TERRAIN uses terrain and obstacle information
supplied by government sources. The data undergoes
verification by Garmin to confirm accuracy of the content,
per TSO-C151b. However, the displayed information
should never be understood as being all-inclusive.
GNC 420(A) Pilot's Guide and Reference
NOTe: The data contained in the TerraiN
databases comes from government agencies.
Garmin accurately processes and cross-validates
the data but cannot guarantee the accuracy and
completeness of the data.
SECTION 10
TERRAIN
10-1