10-22Garmin GTN 625/635/650 Pilot’s Guide 190-01004-03 Rev. KForewordGettingStartedAudio &Xpdr CtrlCom/NavFPLDirect-ToProcWpt InfoMapTrafficTerrainWeatherNearestServices/MusicUtilitiesSystemMessagesSymbolsAppendixIndex10.5 HTAWS (Optional)10.5.1 IntroductionNOTE: TERRAIN, TAWS, HTAWS, or HTERRAIN PROXIMITY functionality willbe available via the Terrain page, depending on the installed hardware andconfiguration. HTAWS or HTERRAIN PROXIMITY are available in softwareversion 4.00, or later.10.5.1.1 OverviewGarmin’s Helicopter Terrain Awareness Warning System (HTAWS) is anoptional feature to increase situational awareness and aid in reducing controlledflight into terrain. Garmin HTAWS is TSO-C194 authorized. Units installed inhelicopters that do not have HTAWS installed will display HTerrain Proximity.This is noted by the five color terrain scale which is appropriate to the lowaltitude operating environment for helicopters.HTAWS provides visual and aural annunciations when terrain and obstaclesare a hazard to the aircraft.HTAWS RelativeTerrain DepictionRotorcraft OwnshipFigure 10-17 Map Page with TerrainNOTE: HTAWS-enabled units can be identified by going to the Terrainpage and checking the lower right-corner for “HTAWS.”10.5.1.2 Operating CriteriaGarmin HTAWS requires the following to operate properly:• The system must have a valid 3D GPS position solution• The system must have a valid terrain/obstacle database.
