Garmin G1000 Pilot’s Guide for Cessna Nav III
190-00498-07 Rev. A
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EIS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICESINDEX
364
HAZARD AVOIDANCE
6.5 TERRAIN PROXIMITY
WARNING: Do not use Terrain Proximity information for primary terrain avoidance. Terrain Proximity is
intended only to enhance situational awareness.
NOTE: Terrain data is not displayed if the aircraft is outside of the installed terrain database coverage area.
G1000TerrainProximity isa terrainawarenesssystem that doesnot complywith TSO-C151bcertication
standards.Itincreasessituational awarenessandaidsin reducingcontrolledight intoterrain(CFIT). Donot
confuseTerrainProximitywiththeoptionalTerrainAwarenessandWarningSystem-ClassB(TAWS-B).TAWS-B
ismoresophisticated androbust,and itisTSO-C151b certied. TerrainProximitydoesnot providewarning
annunciationsorvoicealerts.Itonlyprovidescolorindicationsonmapdisplayswhenterrainandobstacles are
withinacertainaltitudethresholdfromtheaircraft.Althoughtheterrainandobstaclecolormapdisplaysarethe
same,TAWS-Busesmoresophisticatedalgorithmstoassessaircraftdistancefromterrainandobstacles.
TerrainProximityrequiresthefollowingcomponentstooperateproperly:
•Valid3-DGPSposition
•Validterrain/obstacledatabase
TerrainProximitydisplaysaltitudesofterrainandobstructionsrelativetotheaircraftpositionandaltitudewith
referencetoadatabasethatmaycontaininaccuracies.Terrainandobstructionsareshownonlyiftheyareinthe
database.Terrainandobstacleinformationshouldbeusedasanaidtosituationalawareness.Theyshouldnever
be used to navigate or maneuver around terrain.
Note that all obstructions may not be available in the terrain and obstacle database. No terrain and obstacle
informationisshownwithoutavalid3-DGPSposition.
TheG1000GPSreceiverprovides thehorizontalpositionand altitude.GPSaltitude isderivedfromsatellite
position.GPSaltitudeisthenconvertedtotheheightabovegeodetic sealevel(GSL),whichistheheightabove
meansealevelcalculatedgeometrically.GSLaltitudeis usedtodetermineterrainand obstacleproximity.GSL
altitude accuracy is affected by satellite geometry, but is not subject to variations in pressure and temperature that
normallyaffectpressurealtitudesensors.GSLaltitudedoesnotrequirelocalaltimetersettingstodetermineMSL
altitude.Itisawidely-usedMSLaltitudesource.
TerrainandobstacledatabasesarereferencedtoMSL.UsingtheGPSpositionandaltitude,theTerrainProximity
featureportraysa2-Dpictureofthesurroundingterrainandobstaclesrelativetothepositionandaltitudeofthe
aircraft.GPSposition andGSLaltitudeare usedtocalculate andpredicttheaircraft’sightpath inrelationto
thesurroundingterrainandobstacles. Inthisway,thepilotcanviewpredicteddangerous terrainandobstacle
conditions.
DISPLAYING TERRAIN PROXIMITY DATA
ThesymbolsandcolorsinFigure6-115andTable6-13areused torepresentobstaclesandaircraftaltitude
whenthe Terrain ProximityPage is selected for display.  TerrainProximity uses black, yellow,and red to
representterrain information relative to aircraftaltitude.  The color of each obstacle is associated with the
altitude of the aircraft.