Cockpit Reference Guide

Garmin G1000 Pilot’s Guide for the Piper PA-46 Meridian
190-00763-02 Rev. A368
HAZARD AVOIDANCE
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EICAS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICESINDEX
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EICAS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICESINDEX
6.5 TAWS-B
WARNING: Do not use TAWS information for primary terrain avoidance. TAWS is intended only to enhance
situational awareness.
NOTE: Terrain data is not displayed when the aircraft is outside of the terrain database coverage area.
NOTE: The data contained in the TAWS databases comes from government agencies. Garmin accurately
processes and cross-validates the data but cannot guarantee the accuracy and completeness of the data.
TAWS-B(TerrainAwarenessandWarningSystem-ClassB)(ifequipped)isdesignedtoincreasesituational
awareness and to aid in preventing controlled ight into terrain (CFIT).  TAWS-B providesvisual and aural
annunciationswhenterrainandobstaclesarewithinthegivenaltitudethresholdfromtheaircraft.Thedisplayed
alerts and warnings are advisory in nature only.
TAWS-BsatisesTSO-C151bClassBrequirementsforcertication.
TAWS-Brequiresthefollowingtooperateproperly:
•Avalidterrain/obstacle/airportterraindatabase
•Avalid3-DGPSpositionsolution
TAWS-Busesterrainandobstacleinformationsuppliedbygovernmentsources.Terraininformationisbased
onterrainelevationinformationinadatabasethatmaycontaininaccuracies.Individualobstructionsmaybe
shownifavailableinthedatabase.ThedataundergoesvericationbyGarmintoconrmaccuracyofthecontent,
perTSO-C151b.However,thedisplayedinformationshouldneverbeunderstoodasbeingall-inclusiveanddata
maybeinaccurate.
TAWS-BusesinformationprovidedfromtheGPSreceivertoprovideahorizontalpositionandaltitude.GPS
altitude is derived from satellite measurements.  GPS altitude is converted to a mean sea level (MSL)-based
altitude(GPS-MSLaltitude)andisusedtodetermineTAWS-Balerts.GPS-MSLaltitudeaccuracyisaffectedby
factorssuchassatellitegeometry,butitisnotsubjecttovariationsinpressureandtemperaturethatnormally
affectpressurealtitudedevices.GPS-MSLaltitudedoesnotrequirelocalaltimetersettingstodetermineMSL
altitude.Therefore,GPSaltitudeprovidesahighlyaccurateandreliableMSLaltitudesourcetocalculateterrain
andobstaclealerts.
TheterrainandobstacledatabasesusedbyTAWS-Barereferencedtomeansealevel(MSL).UsingtheGPS
positionandGPS-MSLaltitude,TAWS-Bdisplaysa2-Dpictureofthesurroundingterrainandobstaclesrelative
tothepositionandaltitudeoftheaircraft.Furthermore,theGPSpositionandGPS-MSLaltitudeareusedto
calculate and “predict” the aircraft’s ight path in relation to the surrounding terrain and obstacles.  In this
manner,TAWS-Bcanprovideadvancedalertsofpredicteddangerousterrainconditions.
Baro-correctedaltitude(orindicatedaltitude)isderivedbyadjustingthealtimetersettingforlocalatmospheric
conditions.  The most accurate baro-correctedaltitude can be achieved by frequently updating the altimeter
settingtothenearestreportingstationalongtheightpath.However,becauseactualatmosphereconditions
seldommatchthestandardconditionsdenedbytheInternationalStandardAtmosphere(ISA)model(where
pressure,temperature,andlapserateshavexedvalues),itiscommonforthebaro-correctedaltitude(asread