
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
402
HAZARD AVOIDANCE
6.10 GARMIN GTS 800 TRAFFIC
WARNING: The GTS 800 Traffic Advisory System (TAS) is intended for advisory use only to aid the pilot in
visually acquiring traffic. No avoidance maneuvers should be based solely upon TAS traffic information. It
is the responsibility of the pilot in command to see and maneuver to avoid traffic.
NOTE: Pilots should be aware of TAS system limitations. TAS systems require transponders of other aircraft
to respond to system interrogations. If the transponders do not respond to interrogations due phenomena
such as antenna shading or marginal transponder performance, traffic may be displayed intermittently, or
not at all. Aircraft without altitude reporting capability are shown without altitude separation data or climb
descent indication. Pilots should remain vigilant for traffic at all times.
NOTE: TIS is disabled when TAS installed.
TheoptionalGarminGTS800isaTrafcAdvisorySystem(TAS).Itenhancesightcrewsituationalawareness
bydisplayingtrafcinformationfortransponder-equippedaircraft.Thesystemalsoprovidesvisualandaural
trafcalertsincludingvoiceannouncementstoassistinvisuallyacquiringtrafc.
TheGTS800iscapableoftrackingupto45intrudingaircraftequippedwithModeAorCtransponders,and
upto30intrudingaircraftequippedwithModeStransponders.Amaximumof30aircraftwiththehighest
threatpotentialcanbedisplayedsimultaneously.NoTASsurveillanceisprovidedforaircraftwithoutoperating
transponders.
THEORY OF OPERATION
WhentheGTS800isinOperatingMode,theunitinterrogatesthetranspondersofintrudingaircraftwhile
monitoringtransponderreplies.Thesystemusesthisinformationtoderivethedistance,relativebearing,and
ifreported,thealtitudeandverticaltrendforeachaircraftwithinitssurveillancerange.TheGTS800then
calculatesaclosureratetoeachintruderbasedontheprojectedClosestPointofApproach(CPA).Iftheclosure
ratemeetsthethreatcriteriaforaTrafcAdvisory(TA),visualandauralalertingisprovided.
TAS SURVEILLANCE VOLUME
TheGTS800surveillancesystemmonitorstheairspacewithin±10,000feetofownaltitude.Underideal
conditions,theGTS800unitscanstranspondertrafcupto12nmintheforwarddirection.Therangeis
somewhatreducedtothesidesandaftofownaircraftduetothedirectionalinterrogationsignalpatterns.In
areasofgreatertranspondertrafcdensityorwhenTCASII(TrafcAlertandCollisionAvoidanceSystemII)
systemsaredetected,theGTS800automaticallyreducesitsinterrogationtransmitterpower(andtherefore
range)inordertolimitpotentialinterferencefromothersignals.
Whenpairedwitha1090MHzextendedsquittertransponder,theGTS800usesAutomaticDependent
Surveillance - Broadcast (ADS-B) data from participating airborne aircraft transponders to enhance the
positionalaccuracyanddisplayoftrafcwithintheTASsurveillancerange.Trafcdatasuppliedonlyby
ADS-BGroundBasedTransceivers(GBTs)isnotdisplayed.