Ideal Tilt Angle, Earth’s Curvature | Honeywell 880 instruction

PRIMUSr 880 Digital Weather Radar System

Tilt management is often misunderstood. It is crucial to safe operation of airborne weather radar. If radar tilt angles are not properly managed, weather targets can be missed or underestimated.

The upper levels of convective storms are the most dangerous because of the probability of violent windshears and large hail. But hail and winshear are not very reflective because they lack reflective liquid water.

The figures that follow show the relationship between flight situations and the correct tilt angle. The first describes a high altitude situation; the second describes a low altitude situation.

DThe ideal tilt angle shows a few ground targets at the edge of the display (see figure 5- 8).

GROUND

RETURN

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Ideal Tilt Angle

Figure 5- 8

DEarth’s curvature can be a factor if altitude is low enough, or if the selected range is long enough, as shown in figure 5- 9.

GROUND

RETURN

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Earth’s Curvature

Figure 5- 9

A28- 1146- 102- 00	Radar Facts
	5-11

Image 61

Honeywell 880 manual Ideal Tilt Angle, Earth’s Curvature

Contents

Page PRIMUSr 880 Digital Weather Radar System Pilot’s Guide Table of Contents Section Radar Facts Appendices Federal Aviation Administration FAAMaximum Permissible Exposure Level Honeywell Product Support List of Illustrations Federal Aviation Administration FAA Advisory CircularsEnhanced GROUND--PROXIMITY Warning Radar Beam Illumination High Altitude Rain Coming From Unseen Dry Hail List of Tables Introduction A28- 1146- 102 System Configurations Efis only Configuration PRIMUSâ 880 Configurations Left Right Controller Left Side Right Side Dual Control Mode Truth TableRTA Mode Remote Mounted Equipment Model Unit Cockpit Mounted OptionsPrimusr 880 Weather Radar Equipment List Typical PRIMUSâ 880 Weather Radar Components Operating Controls WI- 880 Weather Radar Indicator OperationTypical PRIMUSâ 880 Digital Weather Radar Display Range 3 Gmap Calibrated Gain Rainfall Rate Color Coding Rainfall Rate Color In/hr Mm/hr Fsby Forced Standby TGT Target STB Stabilization Selected Range Minimum Target Target Range Depth NM Range TRB TurbulenceAZ Azimuth SCT Scan Sector Tilt BRT Brightness or BRT/LSS Lightning Sensor System Gain WC- 880 Weather Radar Controller Operation WC- 880 Weather Radar Controller Configurations Tilt Radar SLV LSS Gain EFIS/MFD Radar PRIMUSr 880 Digital Weather Radar System Maximum Permissible Exposure Level Mpel Sect Scan Sector TRB Turbulence Detection Range LSS Lightning Sensor System Option SLV Slave WC- 884 Weather Radar Controller BRT Brightness WC- 884 Weather Radar Controller OperationTGT Target Alert RCT Rain Echo Attenuation Compensation Technique Tilt Mode Rainfall Rate Color In/hr Mm/hr PRIMUSr 880 Digital Weather Radar System Forced Standby Override Hidden Modes Roll Gain Roll OffsetPitch Offset Pitch Gain PRIMUSr 880 Digital Weather Radar System Step Procedure Preliminary Control SettingsPrimusr 880 Power--Up Procedure Cont Normal Operation PRIMUSâ 880 Power- Up Procedure Output Power is Radiated in Test ModeIndicator Test Pattern 120 Scan WX With Text Fault Enabled 319 Efis Test Pattern Typical 120 Scan Shown WX WI--880 Indicator Test Pattern With Text Fault Enabled Radar Mode WeatherStandby REV Test Mode Radar Mode Ground Mapping 4-8 blank Radar Operation Radar Facts Aircraft Heading PRIMUSr 880 Digital Weather Radar System Sea Returns Radar Beam Illumination High Altitude Inch Radiator Tilt Management Radar Beam Illumination Low Altitude Inch Radiator PRIMUSr 880 Digital Weather Radar System Range Scale Line Tilt Limited Earth’s Curvature Ideal Tilt Angle Unaltered Tilt Convective Thunderstorms Tilt Management With Heading Changes Proper Tilt Technique Low Altitude Tilt Management Fast Developing Thunderstorm Rules of Thumb Antenna Size and Impact on Tilt Management Altitude Compensated Tilt ACT Manual Tilt at Low Altitudes Accelerative Error Dynamic ErrorStabilization Pitch and Roll Trim Adjustments Pitch and Roll Trim Adjustments Criteria Stabilization Precheck Stabilization In Straight and Level Flight Check ProcedureLevel Flight Stabilization Check Ground Return Indicating Misalignment Upper Right Symmetrical Ground Returns Ground Return Indicating Misalignment Upper Left Stabilization in Turns Check ProcedureRoll Stabilization Check Roll Stabilization Inoperative 23. The radar unit is in the roll offset In- flight Roll Offset Adjustment Procedure Push the Stab STB button to go to the next menu pitch offset Roll Offset Adjustment Display Final Pitch Offset Adjustment Procedure Pitch Offset Adjustment Roll Gain Adjustment Roll Gain Adjustment Pitch Gain Adjustment Pitch Gain Adjustment Weather Radar Images Interpreting Weather Radar Images PRIMUSr 880 Digital Weather Radar System Radar and Visual Cloud Mass Squall Line Weather Display Calibration Display Levels Related to VIP Levels Typical Variable Gain Control LOW Variable Gain Settings can Eliminate Hazardous TargetsRain Echo Attenuation Compensation Technique React PRIMUSr 880 Digital Weather Radar System React With React SelectedReact on and OFF Indications Turbulence Probability ShadowingDo not FLY Into the Shadow Behind the Cell Probability of Turbulence Presence A Weather Target Turbulence Detection Theory Areas of Turbulence can not Always be Detected by the Radar No Turbulence Total Return Vector Turbulent Turbulence Detection OperationWeather Display With Turbulence PRIMUSâ 880 Digital Weather Radar can only Detect Turbulence Levels From Airman’s Information Manual Hail Size Probability Hail Size Probability Spotting Hail Rain Coming From Unseen Dry Hail Familiar Hailstorm Patterns Overshooting a Storm Short- and Long- Blind Alley Azimuth Resolution in Weather Modes Azimuth Resolution Radome Weather Display Weather Avoidance Nificant Weather MAY not be Displayed Do not Leave the Radar in Variable GAIN. SIGDRY Hail can be Prevalent AT Higher Alti Tudes WITHIN, NEAR, or Above Storm Cells Severe Weather Avoidance Procedures 10 3. Interaction With Other Storms. a thunderstorm that is Step Procedure Storms Situated Behind Intervening Rain Configurations of Individual Echoes Northern HemisphereFall MAY be More Severe than Depicted on Display Typical Hook Pattern Notch Echo, Pendant Shape Avoid V- Notch by 20 Miles Classic Pendant Shape Avoid Pendant by 20 Miles Rain Gradients Avoid Steep Rain Gradients by 20 MilesAvoid ALL Crescent Shaped Echoes by 20 Miles Crescent Shape Line Configurations Line Echo Wave Pattern Lewp Avoid Line Echo Wave Patterns Lewp by 20 Miles Bow- Shaped Line of Thunderstorms Avoid BOW- Shaped Line of Echoes by 20 Miles Turbulence Versus Distance from Storm Core Additional HazardsTurbulence Versus Distance from Storm Edge Ground Mapping Display Ground Mapping Tilt Setting for Maximal Ground Target Display Inch Radiator Range Scale Mpel Boundary Maximum Permissible Exposure Level Mpel In- Flight Troubleshooting Test Mode With Text Faults Enabled Field No Description Fault Data Fields 315 Text Faults Cont Fault Code and Text Fault Relationships IO Fpga REG Text Faults Pilot Messages Describes the pilot messages Honeywell Product Support Honeywell Aerospace Online Technical Publications Web Site Customer SupportCustomer Response Center CRC Abbreviation Equivalent Abbreviations FLTPLN, FP RCT, React Cancellation Federal Aviation Administration FAA Advisory CircularsAppendix a Purpose General Background PrecautionsBody Damage Combustible Materials General Subject ThunderstormsHazards Squall Lines Turbulence Tornadoes Icing Schematic Cross Section of a Thunderstorm LOW Ceiling and Visibility HailEffect on Altimeters Weather Radar Lightning DO’S and DON’TS of Thunderstorm Flying PRIMUSr 880 Digital Weather Radar System Relationship Between Turbulence and Altitude Relationship Between Turbulence and ReflectivityTurbulence and Echo Intensity on NWS Radar WSR Turbulence in Relation to Distance from Storm Core Turbulence Above Storm Tops Turbulence in Relation to Distance from the Storm EdgeTurbulence below Cloud Base Hail in Thunderstorms Maximum Storm Tops USE of Airborne Radar Extrapolation to Different Climbs Appendix B Enhanced Ground-Proximity Warning System EgpwsSystem Operation Egpws Controls Annunciators Push Button Controls Egpws Operation Related Egpws System Operation Egpws Display Figure B--1 Egpws Test Index Index TGT target, 3-6 tilt TRB turbulence Radar facts cont rain echo attenuation Index--5 BRT brightness or BRT/LSS lightning sensor system