Cockpit Reference Guide

190-00763-02 Rev. A
Garmin G1000 Pilot’s Guide for the Piper PA-46 Meridian
335
HAZARD AVOIDANCE
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EICAS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICES INDEX
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EICAS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICES INDEX
PRACTICAL APPLICATION USING THE BASIC TILT SETUP
Withtheantennatiltsetaspreviouslydescribed,anydisplayedtargetreturnshouldbescrutinizedwhen
yingataltitudesbetween2,000and30,000feetAGL.Ifthedisplayedtargetadvancesonthescreento
within5nauticalmilesoftheaircraft,avoidit.Thismaybeeitherweatherorgroundreturnsthatare2,000
feet orlessbelow the aircraft. Raising theantennatilt 4 degreescanhelp separate groundreturns from
weatherreturnsinrelativelyatterrain.Thisalignsthebottomoftheradarbeamparallelwiththeground.
Returntheantennatilttotheprevioussettingafterafewsweeps.
Iftheaircraftisabove29,000feet,becautiousofanytargetreturnthatgetstowithin30nauticalmiles.
Thisislikelyathunderstormthathasatophighenoughthattheaircraftcannotyoveritsafely.
Iftheaircraftaltitudeis15,000feetorlower,settingthedisplayedrangeto60milesmaybemorehelpful.
Closelymonitoranythingthatentersthedisplay.
Also,aftersettinguptheantennatiltangleasdescribedpreviously,groundreturnscanbemonitoredfor
possiblethreats.Therelationshipbetweenantennatiltangle,altitude,anddistanceisonedegreeoftiltequals
100 feet of altitude for every one nautical mile.
Vertical Change of Radar Beam (feet)
Change in Antenna Tilt
10 nm
0
1000
2000
3000
4000
1000
2000
3000
4000
-1°
0°
-2°
-3°
-4°
+1°
+2°
+3°
+4°
Figure 6-49 Vertical Change in Radar Beam per Nautical Mile
Therefore,withtheantennatiltsetsothatthebottomofthebeamisfourdegreesbelowparallelwiththe
ground,atargetreturnat10nmisapproximately4,000feetbelowtheaircraft;at20nm,8,000feet;at50nm,
20,000feet.Inotherwords,atthistiltsetting,agroundreturn(suchasamountainpeak)beingdisplayed
at10nmwouldhaveamaximumdistancebelowtheaircraftof4,000feet.Whenthatgroundtargetreturn
movesto5nm,themaximumdistancebelowtheaircraftis2,000feet.
ThissetupprovidesagoodstartingpointforpracticaluseoftheGWX68.Therearemanyotherfactorsto
considerinordertobecomeprocientatusingweatherradarinallsituations.