Honeywell Primus 880 Pilot'S Manual Download

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PRIMUS

880 Digital Weather Radar System

A28- 1146- 102- 00

Radar Facts

5-31

INTERPRETING WEATHER RADAR IMAGES

From a weather standpoint, hail and turbulence are the principal

obstacles to a safe and comfortable flight. Neither of these conditions

is directly visible on radar. The radar shows only the rainfall patterns

with which these conditions are associated.

The weather radar can see water best in its liquid form, as shown in

figure 5- 25 (not water vapor; not ice crystals; not hail when small and

perfectly dry). It can see rain, wet snow, wet hail, and dry hail when its

diameter is about 8/10 of the radar wavelength or larger. (At X- band,

this means that dry hail becomes visible to the radar at about 1- in.

diameter.)

WET HAIL - GOOD

RAIN - GOOD

WET SNOW - GOOD

DRY HAIL - POOR

DRY SNOW - VERY POOR

VAPOR

ICE CRYSTALS

SMALL DRY HAIL

AD- 46704- R1@

REFLECTIVE LEVELS

WILL NOT REFLECT

Weather Radar Images

Figure 5- 25

Summary of Contents for Primus 880

Page 1: ......

Page 2: ... A28 1146 102 03 September 1996 Revised January 2006 Honeywell International Inc Commercial Electronic Systems 5353 W Bell Rd Glendale Arizona 85308 3912 U S A CAGE 55939 PRIMUSr 880 Digital Weather Radar System Pilot s Guide ...

Page 3: ... 27 Roll Gain 3 27 Pitch Offset 3 27 Pitch Gain 3 28 4 NORMAL OPERATION 4 1 Preliminary Control Settings 4 1 Standby 4 4 Radar Mode Weather 4 4 Radar Mode Ground Mapping 4 6 Test Mode 4 6 5 RADAR FACTS 5 1 Radar Operation 5 1 Tilt Management 5 5 Stabilization 5 18 Dynamic Error 5 18 Accelerative Error 5 18 Pitch and Roll Trim Adjustments 5 19 Stabilization Precheck 5 21 Roll stabilization check 5 ...

Page 4: ...muth Resolution 5 53 Radome 5 54 Weather Avoidance 5 55 Configurations of Individual Echoes Northern Hemisphere 5 60 Line Configurations 5 65 Additional Hazards 5 68 Ground Mapping 5 69 6 MAXIMUM PERMISSIBLE EXPOSURE LEVEL MPEL 6 1 7 IN FLIGHT TROUBLESHOOTING 7 1 Test Mode With TEXT FAULTS Enabled 7 2 Fault Code and Text Fault Relationships 7 5 8 HONEYWELL PRODUCT SUPPORT 8 1 9 ABBREVIATIONS 9 1 A...

Page 5: ...on B 3 EGPWS Operation B 3 EGPWS Display B 4 EGPWS Test B 6 INDEX Index 1 List of Illustrations Figure Page 2 1 PRIMUSR 880 Configurations 2 2 2 2 Typical PRIMUSR 880 Weather Radar Components 2 5 3 1 Typical PRIMUSR 880 Digital Weather Radar Display 3 1 3 2 WI 880 Weather Radar Indicator Front Panel View 3 2 3 3 WI 880 Weather Radar Indicator Display Screen Features 3 3 3 4 WC 880 Weather Radar Co...

Page 6: ...e Thunderstorms 5 12 5 11 Unaltered Tilt 5 12 5 12 Proper Tilt Technique 5 13 5 13 Tilt Management With Heading Changes 5 13 5 14 Fast Developing Thunderstorm 5 14 5 15 Low Altitude Tilt Management 5 14 5 16 Antenna Size and Impact on Tilt Management 5 15 5 17 Rules of Thumb 5 15 5 18 Manual Tilt at Low Altitudes 5 17 5 19 Symmetrical Ground Returns 5 22 5 20 Ground Return Indicating Misalignment ...

Page 7: ... in Weather Modes 5 53 5 41 Weather Display 5 55 5 42 Typical Hook Pattern 5 61 5 43 V Notch Echo Pendant Shape 5 62 5 44 The Classic Pendant Shape 5 63 5 45 Rain Gradients 5 64 5 46 Crescent Shape 5 65 5 47 Line Echo Wave Pattern LEWP 5 66 5 48 Bow Shaped Line of Thunderstorms 5 67 5 49 Ground Mapping Display 5 69 6 1 MPEL Boundary 6 1 7 1 Fault Annunciation on Weather Indicator With TEXT FAULT F...

Page 8: ... for Minimal Ground Target Display 18 Inch Radiator 5 9 5 3 Approximate Tilt Setting for Minimal Ground Target Display 24 Inch Radiator 5 10 5 4 Pitch and Roll Trim Adjustments Criteria 5 20 5 5 Stabilization In Straight and Level Flight Check Procedure 5 21 5 6 Stabilization in Turns Check Procedure 5 23 5 7 In flight Roll Offset Adjustment Procedure 5 25 5 8 Pitch Offset Adjustment Procedure 5 2...

Page 9: ...yed in four bright colors contrasted against a deep black background Areas of very heavy rainfall appear in magenta heavy rainfall in red less severe rainfall in yellow moderate rainfall in green and little or no rainfall in black background Areas of detected turbulence appear in soft white The antenna sweep position indicator is a yellow bar Range marks and identifying numerics displayed in contr...

Page 10: ...re expands the use of the radar indicator to display information such as checklists short and long range navigation displays when used with a Honeywell DATA NAV system and electrical discharge data from Honeywell s LSZ 850 Lightning Sensor System LSS NOTE Refer to Honeywell Pub 28 1146 54 LSZ 850 Lightning Sensor System Pilot s Handbook for more information ...

Page 11: ... indicator The second system configuration uses an RTA and single or dual controllers The single or dual EFIS is the radar display Since there is no radar indicator in this configuration the radar system operating controls are located on the controller With a single controller all cockpit radar displays are identical The dual configuration gives the appearance of having two radar systems on the ai...

Page 12: ...WU 880 CONTROLLER WC 880 MFD AND SINGLE OR DUAL EFIS OPTIONAL 2ND CONTROLLER AD 46690 R2 TRB STAB TGT SECT TILT SLV RADAR GAIN RCT WX SBY GMAP FP TST OFF PULL VAR MAX MIN PULL ACT TRB STAB TGT SECT TILT SLV RADAR GAIN RCT WX SBY GMAP FP TST OFF PULL VAR MAX MIN PULL ACT TRB STAB TGT SECT TILT SLV RADAR GAIN RCT WX SBY GMAP FP TST OFF PULL VAR MAX MIN PULL ACT TRB STAB TGT SECT TILT SLV RADAR GAIN ...

Page 13: ... operate in the dual mode The MFD can be slaved to either controller to duplicate the data displayed on the selected side Table 2 1is a truth table for dual control modes Left Controller Mode Right Controller Mode Left Side NOTE 1 Right Side NOTE 1 RTA Mode OFF OFF OFF OFF OFF OFF Standby SLV Standby Standby Standby Standby OFF Standby SLV Standby Standby OFF ON SLV ON ON ON ON OFF ON SLV ON ON St...

Page 14: ...tilt Video data is suppressed The transmitter is inhibited 5 The MFD if used can repeat either left or right side data depending upon external switch selection Equipment covered in this guide is listed in table 2 2 and shown in figure 2 2 Model Unit Part No Cockpit Mounted Options WI 880 Weather Radar Indicator 7007700 401 402 403 404 WC 880 Weather Radar Controller 7008471 4XX WC 884 Weather Rada...

Page 15: ...0 Digital Weather Radar System A28 1146 102 00 System Configurations 2 5 2 6 blank WC 884 CONTROLLER WC 880 CONTROLLER WI 880 INDICATOR WU 880 RTA AD 46691 Typical PRIMUSâ 880 Weather Radar Components Figure 2 2 ...

Page 16: ... that are described in this section they are in order of description D WI 880 Weather Radar Indicator D WC 880 Weather Radar Controller D WC 884 Weather Radar Controller AZ AUTO TILT 50 40 30 20 10 1 0 2 1 3 4 T Typical PRIMUSâ 880 Digital Weather Radar Display Figure 3 1 The controls and display features of the WI 880 Weather Radar Indicator are indexed and identified in figure 3 2 Brightness lev...

Page 17: ...CT TGT AZ SCT RANGE GMAP WX FP TST SBY OFF GAIN MIN MAX PULL VAR PULL ACT TILT BRT STB TRB 7 8 9 10 11 2 1 3 4 5 6 12 10 BRT OFF CLR TST SBY LX WI 880 Weather Radar Indicator Front Panel View Figure 3 2 1 Display Area See figure 3 3and the associated text which explains thealphanumeric display ...

Page 18: ...Figure 3 3 2 Function Switch A rotary switch used to select the following functions D OFF This position turns off the radar system D SBY Standby This position places the radar system in standby a ready state with the antenna scan stopped the transmitter inhibited and the display memory erased STBY in white is shown in the mode field If SBY is selected before the initial RTA warmup period is comple...

Page 19: ... targets NOTE REACT TGT or TURB modes are not selectable in GMAP WARNING WEATHER TYPE TARGETS ARE NOT CALIBRATED WHEN THE RADAR IS IN THE GMAP MODE BECAUSE OF THIS DO NOT USE THE GMAP MODE FOR WEATHER DETECTION As a constant reminder that GMAP is selected the alphanumerics are changed to green the GMAP legend is shown in the mode field and the color scheme is changed to cyan yellow and magenta Cya...

Page 20: ...path and the WX mode should be selected to view it NOTE The TGT function is inoperative when a checklist is displayed D TST Test The TST position selects the radar test mode A special test pattern is displayed to verify system operation The TEST legend is shown in the mode field Refer to Section 4 Normal Operations for a description of the test pattern WARNING UNLESS THE SYSTEM IS IN FORCED STANDB...

Page 21: ...red area the target alert legend changes from the green T armed condition to the yellow TGT warning condition See the target alert characteristics in table 3 2for a target description These annunciations advise the pilot of potentially hazardous targets directly in front of the aircraft that are outside the selected range When a yellow warning is received the pilot should select longer ranges to v...

Page 22: ...should be considered dangerous All targets in the cyan field are displayed as fourth level precipitation magenta REACT is available in the WX mode only and selecting REACT forces the system to preset gain When engaged the white RCT legend is displayed in the REACT field NOTES 1 REACT S three main functions attenuation compensation cyan field and forcing targets to magenta are switched on and off w...

Page 23: ...TURBULENCE CAN EXIST WITHIN ANY STORM CELL REFER TO SECTION 5 RADAR FACTS OF THIS GUIDE FOR ADDITIONAL INFORMATION Selecting the 100 200 or 300 mile range turns off turbulence detection The T is deleted from the mode annunciation Subsequently selecting ranges of 50 miles or less re engages turbulence detection A description of the turbulence detection capabilities and limitations is given in Secti...

Page 24: ...Refer to the LSZ 850 Lightning Sensor System Pilot s Handbook for a detailed description of LSS operation 11 TILT The TILT knob is a rotary control that is used to select the tilt angle of the antenna beam with relation to the horizon CW rotation tilts beam upward to 15_ ccw rotation tilts beam downward to 15_ A digital readout of the antenna tilt angle is displayed on the CRT with 0 5_ resolution...

Page 25: ...splayed in the color bar Variable gain is useful for additional weather analysis and for ground mapping In WX mode variable gain can increase receiver sensitivity over the calibrated level to show very weak targets or it can be reduced below the calibrated level to eliminate weak returns WARNING HAZARDOUS TARGETS MAY BE ELIMINATED FROM THE DIS PLAY WITH LOW SETTINGS OF VARIABLE GAIN In the GMAP mo...

Page 26: ... levels for all legend and controls on the indicator are controlled by the dimming bus for the aircraft panel 7 6 5 4 3 8 1 9 10 2 TRB STAB TGT SECT TILT PULL ACT CLR TST LX SBY OFF LSS SLV RADAR GAIN RCT WX SBY GMAP FP TST OFF PULL VAR MAX MIN AD 46695 R1 OFF 7 6 5 4 3 8 1 9 2 TRB STAB TGT SECT TILT PULL ACT SLV RADAR GAIN RCT WX SBY GMAP FP TST OFF PULL VAR MAX MIN AD 46696 R1 OFF WC 880 Weather...

Page 27: ...X MIN AD 46697 R1 PULL ACT WC 880 Weather Radar Controller Configurations Figure 3 4 NOTES 1 With a controller without built in range control range is controlled from the installed EFIS navigation display 2 Controllers are available with and without the LSS function 3 Whenever single or dual radar controllers are used the radar data is displayed on the EFIS and or an MFD or navigation display ND ...

Page 28: ...mitter and antenna scan are inhibited and the display memory is erased When the warmup is complete the system automatically switches to the WX mode The system in preset gain is calibrated as described in table 3 3 Rainfall Rate Color in hr mm hr 04 16 1 4 Green 16 47 4 12 Yellow 47 2 12 50 Red 2 5 0 Magenta Rainfall Rate Color Coding Table 3 3 D RCT Rain Echo Attenuation Compensation Technique Thi...

Page 29: ...cs are changed to green the GMAP legend is displayed in the mode field and the color scheme is changed to cyan yellow and magenta Cyan represents the least reflective return yellow is a moderate return and magenta is a strong return If GMAP is selected before the initial RTA warmup period is complete approximately 45 to 90 seconds the white WAIT legend is displayed in the mode field In wait mode t...

Page 30: ...DBY THE TRANSMIT TER IS ON AND RADIATING X BAND MICROWAVE ENERGY IN TEST MODE REFER TO SECTION 6 MAXIMUM PERMISSIBLE EXPOSURE LEVEL MPEL D FSBY Forced Standby FSBY is an automatic nonselectable radar mode As an installation option the indicator can be wired to the weight on wheels WOW squat switch When wired the RTA is in the FSBY mode when the aircraft is on the ground In FSBY mode the transmitte...

Page 31: ...e tilt command source ACT command or manual tilt command WARNINGS 1 TO AVOID FLYING UNDER OR OVER STORMS FREQUENTLY SELECT MANUAL TILT TO SCAN BOTH ABOVE AND BELOW YOUR FLIGHT LEVEL 2 ALWAYS USE MANUAL TILT FOR WEATHER ANALYSIS 3 SECT Scan Sector The SECT switch is an alternate action button that is used to select either the normal 12 looks minute 120_ scan or the faster update 24 looks minute 60_...

Page 32: ...ller Target Alert Characteristics Table 3 4 5 STB Stabilization The STB button turns the pitch and roll stability ON and OFF It is also used with the STB adjust mode and to override forced standby NOTE Some controllers annunciate OFF when stabilization is OFF 6 TRB Turbulence Detection TRB is a switch used to select the turbulence detection mode of operation The TRB mode can only be selected if th...

Page 33: ...permits selection of ranges in WX mode from 5 to 300 NM full scale In the flight plan FPLN mode additional ranges of 500 and 1000 miles are permitted The up arrow selects increasing ranges while the down arrow selects decreasing ranges One half the selected range is annunciated at the one half scale range mark on the EHSI NOTE Some Integrated avionics systems incorporate radar range with the map d...

Page 34: ...ations With dual controllers one controller can be slaved to the other by selecting OFF on that controller only with the RADAR mode switch This slaved condition is annunciated with the SLV annunciator In the slaved condition both controllers must be off before the radar system turns off 10 LSS Lightning Sensor System Option The LSS switch is an optional four position rotary switch that selects the...

Page 35: ... switch is a rotary control that is used to set the radar raster brightness on the EFIS display 2 TGT Target Alert The TGT switch is an alternate action button that enables and disables the radar target alert feature Target alert is selectable in all but the 300 mile range When selected target alert monitors beyond the selected range and 7 5_ on each side of the aircraft heading If a return with c...

Page 36: ...tabilized It automatically compensates for roll and pitch maneuvers refer to Section 5 Radar Facts for a description of stabilization The amber STB annunciator appears on the screen It is also used with the STB adjust mode and to override forced standby 4 RCT Rain Echo Attenuation Compensation Technique Selecting RCT forces the system to preset gain When RCT is selected the green REACT legend is d...

Page 37: ...gaged if previously selected Subsequent selection of ranges of 50 miles or less re engages turbulence detection A description of the turbulence detection capabilities and limitations can be found in Section 5 Radar Facts of this guide 6 TILT The TILT switch is a rotary control used to select tilt angle of antenna beam with relation to the horizon CW rotation tilts beam upward to 15_ ccw rotation t...

Page 38: ...s detected the target alert armed annunciation switches to the alert annunciation amber TGT This advisory indicates that a hazardous target is in the aircraft s flightpath and the WX mode should be selected 8 SLV Slave The SLV annunciator is a dead front annunciator thatis onlyused indual controller installations With dual controllers one controller can be slaved to the other by selecting the RADA...

Page 39: ...nroute weather detection If WX is selected before the initial RTA warmup period is complete a flashing WAIT legend is displayed In WAIT mode the transmitter and antenna scan are inhibited and the memory is erased When the warmup is complete the system automatically switches to the WX mode and a green WX is displayed in mode field The system in preset gain is calibrated given in table NO TAG Rainfa...

Page 40: ... the memory is erased and the amber FSBY legend is displayed in the mode field When in the forced standby mode pushing the STAB button 4 times in 3 seconds exits the mode FSBY mode is a safety feature that inhibits the transmitter on the ground to eliminate the X band microwave radiation hazard Refer to Section 6 Maximum Permissible Exposure Level MPEL NOTE In dual installations overriding the for...

Page 41: ...s that are summarized as follows D Forced Standby FSBY Override D Roll Offset D Roll Gain NOTE D Pitch Offset NOTE D Pitch Gain NOTE NOTE At the time of installation the programming strap STAB TRIM ENABLE determines if the roll and pitch gain and pitch offset adjustment features are available Consult the aircraft installation information to determine the installed configuration Forced Standby Over...

Page 42: ...rects the installation at bank angles over 20 for unsymmetrical radar displays D Entry Method Selected by sequencing through the roll offset and pitch offset menus with the STAB button Refer to Section 5 Radar Facts table 5 9 D Control Pull GAIN knob out and use it D Exit Method Push STAB once to continue with the next adjustment Pitch Offset D Function Adjusts the pitch attitude of the antenna to...

Page 43: ... GAIN knob in Push STAB to exit and save settings NOTES 1 If installation is configured only for roll offset adjustment pushing the STB button saves and exits after the roll offset adjustment is made 2 Upon exiting stabilization may be either OFF or ON depending on how many times it was pushed during the procedure Be sure to set stabilization OFF or ON as desired 3 If upon entering the adjustment ...

Page 44: ...r is free of large metallic objects such as hangars or other aircraft for a minimum distance of 100 feet 30 meters and tilt the antenna fully upwards D Do not operate the radar system during aircraft refueling or during refueling operations within 100 feet 30 meters D Do not operate the radar if personnel are standing too close to the 120_ forward sector of aircraft Refer to Section 6 Maximum Perm...

Page 45: ...ed standby WARNING OUTPUT POWER IS RADIATED IN TEST MODE 6 After the warm up select the Test mode and verify that the test pattern is displayed as shown in figure 4 1 If the radar is being used with an EFIS the test pattern is similar to that shown in figures 4 2 and 4 3 Verify that the yellow antenna position indicator API is shown at the top of the display 7 Verify that the azimuth marks target ...

Page 46: ... VAR TEXT AREA GREEN ANTENNA TILT ANGLE YELLOW NOTES 1 2 IF THE BITE DETECTS A FAULT IN TEST MODE FAIL N WILL BE SHOWN N IS A FAULT CODE ANY FAULT CODE CAN ALSO BE DISPLAYED IN THE MAINTENANCE MODE IN THAT CASE IT REPLACES THE ANTENNA TILT ANGLE TARGET ALERT GREEN SELECTED AMBER TGT DETECTED VARIABLE GAIN AMBER NOTES 1 Refer to the specific EFIS document for a detailed description 2 The example sh...

Page 47: ...en the pilot wants to keep power applied to the radar without transmitting Radar Mode Weather For purposes of weather avoidance pilots should familiarize themselves with FAA Advisory Circular AC 00 24B 1 20 83 Subject Thunderstorms The advisory circular is reproduced in Appendix A of this guide To help the pilot categorize storms as described in the advisory circular referenced above the radar rec...

Page 48: ... be seen if there are no intervening targets The RCT feature includes attenuation compensation Refer to Section 5 Radar Facts of this guide for a description of attenuation compensation Rainfall causes attenuation and attenuation compensation modifies the color calibration to maintain calibration regardless of the amount of attenuation Modifying the color calibration results in a change in the poi...

Page 49: ... clear visibility where the radar display can be visually compared with the terrain TEST MODE The PRIMUSâ 880 Digital Weather Radar System has a self testmode and a maintenance function In the self test TST mode a special test pattern is displayed as illustrated earlier in this section The functions of this pattern are as follows D Color Bands A series of green yellow red magenta white bands indic...

Page 50: ...ND Faults are normally shown when test is selected NOTES 1 Some weather failures on EFIS are annunciated with an amber WX 2 Some EFIS installations can power up with an amber WX if weather radar is turned off 3 If the fault code option is selected they are shown with the FAIL annunciation e g FAIL 13 ...

Page 51: ...o the target range Because the antenna beam is scanning right and left in synchronism with the sectoring sweep on the indicator the bearing of the target is found as shown in figure 5 1 The indicator with the radar is called a plan position indicator PPI type When an architect makes a drawing for a house one of the views he generally shows is a plan view a diagram of the house as viewed from above...

Page 52: ...at the indicator presents imagine that the storm is a loaf of sliced bread standing on end From a point close to the surface of earth it towers to a high altitudesummit Without upsetting the loaf of bread the radar removes a single slice from the middle of the loaf and places this slice flat upon the table Looking at the slice of bread from directly above a cross section of the loaf can be seen in...

Page 53: ...o the antenna Antenna Beam Slicing Out Cross Section of Storm During Horizontal Scan Figure 5 2 Weather radar can occasionally detect other aircraft but it is not designed for this purpose and should never be considered a collision avoidance device Nor is weather radar specifically designed as a navigational aid but it can be used for ground mapping by tilting the antenna downward Selecting the GM...

Page 54: ...rth south east west spokes overlaying the ground map The second phenomenon is associated with radar returns from water surfaces generally called sea clutter as shown in figure 5 3 Calm water reflects very low radar returns since it directs the radar pulses onward instead of backward i e the angle of incidence from mirrored light shone on it at an angle The same is true when viewing choppy water fr...

Page 55: ...ltitude that is illuminated by the flat plate radiator during level flight with 0_ tilt Figures 5 6 and 5 7 show a representative low altitude situation with the antenna adjusted for 2 8_ up tilt ELEVATION IN FEET 80 000 70 000 60 000 50 000 30 000 20 000 10 000 0 0 25 50 RANGE NAUTICAL MILES 100 AD 35693 CENTER OF RADAR BEAM 20 000 FT 20 000 FT 41 800 FT 41 800 FT 10 500 FT 10 500 FT 7 9 ZERO TIL...

Page 56: ... 500 FT 1 15 7 9 4 200 FT 4 200 FT ANTENNA ADJUSTED FOR 2 8 UPTILT 10 500 FT Radar Beam Illumination Low Altitude 12 Inch Radiator Figure 5 6 0 RANGE NAUTICAL MILES AD 17719 ELEVATION IN FEET 40 000 30 000 20 000 10 000 5 000 0 10 20 30 40 50 60 70 80 ANTENNA ADJUSTED FOR 2 8 UPTILT 5 6 3 000 FT 3 000 FT 7 400 FT 7 400 FT 14 000 FT 14 000 FT Radar Beam Illumination Low Altitude 18 Inch Radiator Fi...

Page 57: ...ere with viewing of weather targets Usually this can be done by tilting the antenna downward in 1_ increments until ground targets begin to appear at the displayperiphery Ground returns can be distinguished from strong storm cells by watching for closer ground targets with eachsmall downwardincrement of tilt The more the downward tilt the closer the ground targets that are displayed When ground ta...

Page 58: ...1 1 0 1 1 246 230 213 195 174 151 123 87 78 67 55 39 LINE OF SIGHT LIMITED REGION TILT LIMITED REGION AD 29830 R2 5 10 2 3 4 2 4 6 8 10 12 3 6 1 0 1 2 11 2 5 4 2 0 Approximate Tilt Setting for Minimal Ground Target Display 12 Inch Radiator Table 5 1 Tilt angles shown are approximate Where the tilt angle is not listed the operator must exercise good judgment NOTE The line of sight distance is nomin...

Page 59: ... 5 6 8 6 6 5 10 7 6 11 8 6 12 8 7 11 8 7 10 9 13 246 230 213 195 174 151 123 87 78 67 55 39 LINE OF SIGHT LIMITED REGION TILT LIMITED REGION AD 35710 Approximate Tilt Setting for Minimal Ground Target Display 18 Inch Radiator Table 5 2 Tilt angles shown are approximate Where the tilt angle is not listed the operator must exercise good judgment NOTE The line of sight distance is nominal Atmospheric...

Page 60: ...1 1 0 0 0 5 4 3 2 1 7 7 3 9 6 2 0 0 2 1 4 6 8 8 3 2 1 0 1 1 1 1 1 1 1 1 0 0 8 6 4 2 Range Scale NM Altitude Feet TILT LIMITED REGION LINE OF SIGHT LIMITED REGION AD 50232 Approximate Tilt Setting for Minimal Ground Target Display 24 Inch Radiator Table 5 3 Tilt angles shown are approximate Where the tilt angle is not listed the operator must exercise good judgement NOTE The line of sight distance ...

Page 61: ... 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 D The ideal tilt angle shows a few ground targets at the edge of the display see figure 5 8 AD 35694 GROUND RETURN Ideal Til...

Page 62: ...00 feet above the freezing level as shown in figure 5 10 AD 35696 FREEZING LEVEL Convective Thunderstorms Figure 5 10 The aircraft in figure 5 10 has a clear radar indication of the thunderstorm probably with a shadow in the ground returns behind it D If the tilt angle shown in figure 5 11 is not altered the thunderstorm appears to weaken as the aircraft approaches it AD 35697 FREEZING LEVEL Unalt...

Page 63: ... as shown in figure 5 12 AD 35698 FREEZING LEVEL Proper Tilt Technique Figure 5 12 D After heading changes in a foul weather situation the pilot should adjust the tilt to see what was brought into the aircraft s flightpath by the heading changes as shown in figure 5 13 AD 30429 DISPLAY BEFORE TURN DISPLAY AFTER TURN THUNDERSTORM WAS OUT OF DISPLAY BEFORE TURN AND IS NOW UNDER BEAM Tilt Management ...

Page 64: ...t can be large enough to damage the aircraft by the time it arrives at the storm AD 35699 FREEZING LEVEL THUNDERSTORM MATURES AS IT APPROACHES Fast Developing Thunderstorm Figure 5 14 D At low altitude the tilt should be set as low as possible to get ground returns at the periphery only as shown in figure 5 15 CORRECT WRONG FREEZING LEVEL AD 35700 Low Altitude Tilt Management Figure 5 15 Excess up...

Page 65: ... BEAM 18 IN ANTENNA HAS 5 6 BEAM 24 IN ANTENNA HAS 4 2 BEAM Antenna Size and Impact on Tilt Management Figure 5 16 NOTE A 10 inch antenna is shown for illustration purposes only D Some of the rules of thumb are described below and shown in figure 5 17 A 1_ look down angle looks down 100 ft per mile Bottom of beam is 1 2 beam width below tilt setting A 12 inch antenna grazes the ground at 100 NM if...

Page 66: ...d level is a factor during low altitude flight especially when flying in mountainous areas The ground targets that are usually at the edge of the display tend to migrate to the middle of the display This also happens when longer ranges 200 NM to 300 NM are selected and the altitude is such that the earth s curvature is a factor In ACT the range control can be used to sweep the beam along the groun...

Page 67: ...PRIMUSr 880 Digital Weather Radar System A28 1146 102 00 Radar Facts 5 17 AD 35703 25 50 100 NM Manual Tilt at Low Altitudes Figure 5 18 ...

Page 68: ...titude is corrected for it Extremely small errors of less than 1_ can be detected and compensated However the point is ultimately reached where dynamic error is too small to be detected Without detection there is no compensation Accelerative Error One of the most common forms of error seen in a radar antenna stabilization system results from forces of acceleration on the aircraft equipped with a v...

Page 69: ...n errors are taken into account maintaining accuracy of 1 2 of 1_ or less is not always possible Adjust the antenna tilt by visually observing the ground return Then slowly tilt the antenna upward until terrain clutter no longer enters the display except at the extreme edges If ground display is observed on one side but not on the other the stabilization system is somewhat in error but it is proba...

Page 70: ...allation not all of the adjustments shown in table 5 4 are available If STAB TRIM ENABLE programming strap is open only the roll offset adjustment is available If STAB TRIM ENABLE is grounded all four adjustments are available Consult the installation configuration information for details 2 After any adjustment procedure is completed monitor the ground returns displayed by the radar during several...

Page 71: ... the 50 mile range 3 Rotate the tilt control upward until all ground returns disappear 4 Rotate the tilt downward until ground returns just begin to show 5 After several antenna sweeps verify that ground returns are equally displayed figure 5 19 If returns are only on one side of the radar screen or uneven across the radar screen a misalignment of the radar antenna mounting is indicated This probl...

Page 72: ...gital Weather Radar System A28 1146 102 00 Radar Facts 5 22 10 5 15 20 AD 17720 R1 GMAP Symmetrical Ground Returns Figure 5 19 10 5 15 20 AD 17721 R1 GMAP Ground Return Indicating Misalignment Upper Right Figure 5 20 ...

Page 73: ... the right 2 Note the radar display It should contain appreciably no more returns than found during level flight Figure 5 22 indicates that roll stabilization is inoperative 3 If returns display on the right side of radar indicator the radar system is understabilizing 4 Targets on the left side of the radar display indicate the system is Overstabilizing Refer to table 5 9 for roll gain adjustment ...

Page 74: ... ground targets on the indicator For example a 1 precession error which would probably not be noticed on the gyro horizon moves the antenna beam approximately 10 500 feet at a point 100 NM from the aircraft If ground targets between 50 and 80 NM depending on aircraft altitude and the actual setting of the tilt control 10 5 15 20 AD 17723 R1 GMAP Roll Stabilization Inoperative Figure 5 22 ...

Page 75: ... the tilt down until a solid band of ground returns are shown on the screen Then adjust the tilt until the green region of the ground returns start at about 20 NM 5 On the WC controller select RCT OFF 6 Select STAB STB 4 times within 3 seconds A display with text instructions will be displayed See figure 5 23 The radar unit is in the roll offset adjustment mode 7 Pull out the GAIN knob to make a r...

Page 76: ...ush the STAB STB button to go to the next menu pitch offset NOTE Once set the roll compensation is stored in nonvolatile memory in the RTA It is remembered when the system is powered down In flight Roll Offset Adjustment Procedure Table 5 7 WX Roll Offset Adjustment Display Initial Figure 5 23 ...

Page 77: ...PRIMUSr 880 Digital Weather Radar System A28 1146 102 00 Radar Facts 5 27 WX Roll Offset Adjustment Display Final Figure 5 24 ...

Page 78: ...e shown on the screen Then adjust the tilt until the green region of the ground returns start at about 20 NM 5 Select RCT OFF 6 Select STAB STB 4 times within 3 seconds The roll offset display is shown 7 From the roll offset entry menu push the STAB STB button once more to bring up the pitch offset entry menu 8 To change the pitch offset value pull out the GAIN knob and rotate it The offset range ...

Page 79: ... the tilt until the green region of the ground returns start at about 20 NM 5 On the WC controller select variable gain pull WX and REACT OFF VAR shows on the display 6 Select STAB STB 4 times within 3 seconds A display with text instructions is shown 7 From the roll offset entry menu push the STAB STB button twice more to bring up the roll gain entry menu 8 To change the roll gain value pull out ...

Page 80: ...region of the ground returns start at about 20 NM 5 On the WC controller select variable gain pull WX and REACT OFF VAR shows on the display 6 Push STAB STB 4 times within 3 seconds A display with text instruction is shown 7 From the roll offset entry menu push the STAB STB button 3 more times to bring up the pitch gain entry menu 8 To change the pitch gain value pull out the GAIN knob and rotate ...

Page 81: ... associated The weather radar can see water best in its liquid form as shown in figure 5 25 not water vapor not ice crystals not hail when small and perfectly dry It can see rain wet snow wet hail and dry hail when its diameter is about 8 10 of the radar wavelength or larger At X band this means that dry hail becomes visible to the radar at about 1 in diameter WET HAIL GOOD RAIN GOOD WET SNOW GOOD...

Page 82: ...ot zones of present and developing turbulence Some knowledge ofmeteorology is required to identify these areas as being turbulent The most important fact is that the areas of maximum turbulence occur where the most abrupt changes from light or no rain to heavy rain occur The term applied to this change in rate is rain gradient The greater the change in rainfall rate the steeper the rain gradient T...

Page 83: ...condenses and builds into raindrops heavy enough to fall downward through the updraft When this precipitation is heavy enough it can reverse the updraft Between these downdrafts shafts of rain updrafts continue at tremendous velocities It is not surprising therefore that the areas of maximum turbulence are near these interfaces between updraft and downdraft Keep these facts in mind when tempted to...

Page 84: ...tion shows that the rainfall is steadily diminishing on the left while it is very heavy in two mature cells and increasing rapidly in a third cell to the right The safest and most comfortable course lies to the left where the storm is decaying into a light rain The growing cell on the right should be given a wide berth AD 12058 R1 BEST DETOUR OUTLINE OF RAIN AREA VISIBLE TO RADAR DECAYING CELLS AR...

Page 85: ...overed in the RCT description intervening attenuating rainfall reduces the calibrated range and the radar can incorrectly depict the true cell intensity The radar calibration includes a nominal allowance for radome losses Excessive losses in the radome seriously affect radar calibration One possible means of verification is signal returns from known ground targets It is recommended that you report...

Page 86: ...N 125 5 INTENSE 5 50 125 2 5 VERY STRONG 4 25 50 1 2 STRONG 3 12 25 0 5 1 MODERATE 2 2 5 12 0 1 0 5 WEAK 1 0 25 2 5 0 01 0 1 STORM CATEGORY VIP LEVEL RAINFALL RATE MM HR IN HR VIDEO INTEGRATED PROCESSOR CATEGORIZATIONS REFLECTIVITY 300 NM THE THRESHOLD FOR THE VIP LEVELS CAN BE REALIZED WHEN THERE IS NO INTERVENING RADAR SIGNAL ATTENUATION WITH RCT SELECTED RCT BLUE FIELD OCCURS WHEN THE MINIMUM R...

Page 87: ...eywell s REACT feature has three separate but related functions D Attenuation Compensation As the radar energy travels through rainfall the raindrops reflect a portion of the energy back toward the airplane This results in less energy being available to detect raindrops at greater ranges This process continues throughout the depth of the storm resulting in a phenomenon known as attenuation The amo...

Page 88: ...iver gain is adjusted to maintain target calibration Since there is a maximum limit to receiver gain strong targets high attenuation levels cause the receiver to reach its maximum gain value in a short time short range Weak or no targets low attenuation levels cause the receiver to reach its maximum gain value in a longer time longer range Once the receiver reaches its maximum gain value weather t...

Page 89: ...PRIMUSr 880 Digital Weather Radar System A28 1146 102 00 Radar Facts 5 39 With REACT Selected REACT REACT ON and OFF Indications Figure 5 28 ...

Page 90: ...ws the following D There is a 100 probability of light turbulence occurring in any area of rain D A level one storm all green has virtually no chance of containing severe or extreme turbulence but has between a 5 and 20 chance that moderate turbulence exists D A level two storm one containing green and yellow returns has virtually no probability of extreme turbulence but has a 20 to 40 chance of m...

Page 91: ...s any additional information about the rainfall rate until the magenta threshold is reached A red return covers a range of turbulence probabilities and the worst case must be assumed especially since extreme destructive turbulence is born in the red zone Therefore once the red threshold is reached the risk in penetration becomes totally unacceptable Likewise once the magenta threshold is reached i...

Page 92: ...ple the data returned from pulse one in range bin 34 is compared to the data returned from pulse two in range bin 34 This process continues throughout the entire area covered by the radar all range bins and a turbulence decision is made for each range bin When turbulence is detected in any bin the color of that bin is made white The return data being compared is the total return vector TRV TRV is ...

Page 93: ...sults in a change in the individual return vectors from each raindrop and a commensurate change in the total return vector Therefore if there is a significant difference between pairs of total return vectors for the same range bin that bin contains turbulence and is displayed in white This is illustrated by comparing figures 5 30 and 5 32 The presence of turbulence is detected by comparing the amp...

Page 94: ...PRIMUSr 880 Digital Weather Radar System A28 1146 102 00 Radar Facts 5 44 Total Return Vector Figure 5 30 AD 17726 R1 No Turbulence Figure 5 31 ...

Page 95: ...s on the turbulence detection mode Areas of detected turbulence are displayed in soft white as shown in figure 5 33 Soft white is a high contrast shade of white that has a slight gray appearance Weather Display With Turbulence Figure 5 33 If any range greater than 50 miles is selected turbulence detection turns off and remains off until 50 miles or less is reselected Similarly if any mode other th...

Page 96: ...ir turbulence WARNING THE PRIMUSâ 880 DIGITAL WEATHER RADAR CAN ONLY DETECT TURBULENCE WITHIN AREAS OF PRECIPITATION IT CANNOT DE TECT CLEAR AIR TURBULENCE The turbulence detection threshold is moderate turbulence That is any area of raindrop motion that is detected as moderate severe or extreme turbulence is displayed in white Areas shown as turbulent are at least moderate turbulence and can be s...

Page 97: ...upt changes in altitude and or attitude It usually causes large variations in indicated airspeed Aircraft may be momentarily out of control Occupants are forced violently against seat belts or shoulder straps Unsecured objects are tossed about Turbulence Levels From Airman s Information Manual Figure 5 34 Hail Size Probability Whenever the radar shows a red or magenta target theentire stormcell sh...

Page 98: ...ptively weak or absent radar returns When flying above the freezing level hail can be expected in regions aboveand aroundwet storm cells found at lower altitudes The hail is carried up to the tropopause by strong vertical winds inside the storm In large storms these winds can easily exceed 200 kt making them very dangerous Since the core of such a storm is very turbulent but largely icy the red co...

Page 99: ...sing a tilt setting that has the radar look into the area of maximum reflectivity 5000 to 20 000 ft gives the strongest radar picture However the tilt setting must not be left at this setting Periodically the pilot should look up and down from this setting to see the total picture of the weather in the flightpath Often hailstorms generate weak but characteristic patterns like those shown in figure...

Page 100: ... again in figure 5 38 When flying at higher altitudes a storm detected on the long range setting can disappear from the display as it is approached The pilot should not be fooled into believing the storm has dissipated asthe aircraftapproaches it The possibility exists that the radiated energy is being directed from the aircraft antenna above the storm as the aircraft gets closer If this is the ca...

Page 101: ...gure 5 39 This is the blind alley or box canyon situation Pilots can find themselves in this situation if they habitually fly with the radar on the short range The short range returns show an obvious corridor between two areas of heavy rainfall but the long range setting shows the trap Both the near and far weather zones could be avoided by a short term course change of about 45_ to the right Alwa...

Page 102: ...PRIMUSr 880 Digital Weather Radar System A28 1146 102 00 Radar Facts 5 52 THE BLIND ALLEY 40 20 LONG RANGE 20 SHORT RANGE AD 12062 R1 Short and Long Blind Alley Figure 5 39 ...

Page 103: ...om the targets at position A At this distance the beam width is spreading As the beam scans across the two targets there is no point at which beam energy is not reflected either by one target or the other because the space between the targets is not wide enough to pass the beam width In target position B the aircraft is closer to the same two targets the beam width is narrower and the targets sepa...

Page 104: ...use reverberant echoes within the radome the condition might be indicated by the appearance of nonexisting targets The radome can also cause refractive distortion which would make it appear that the TILT control was out of adjustment or that bearing indications were somewhat erroneous A radome with ice or water trapped within its walls can cause significant attenuation and distortion of the radar ...

Page 105: ...AVOIDANCE Figure 5 41 illustrates a typical weather display in WX mode Recommended procedures when using the radar for weather avoidance are given in table 5 12 The procedures are given in bold face explanations of the procedure follow in normal type face Weather Display Figure 5 41 ...

Page 106: ...tch back to preset gain WARNING DO NOT LEAVE THE RADAR IN VARIABLE GAIN SIG NIFICANT WEATHER MAY NOT BE DISPLAYED 3 Any storm with reported tops at or greater than 20 000 feet must be avoided by 20 NM WARNING DRY HAIL CAN BE PREVALENT AT HIGHER ALTI TUDES WITHIN NEAR OR ABOVE STORM CELLS AND SINCE ITS RADAR REFLECTIVITY IS POOR IT MAY NOT BE DETECTED 4 Use increased gain rotate GAIN control to its...

Page 107: ...ally passes out of and under the radar beam 6 When flying at low altitudes rotate tilt upward frequently to avoid flying under a thunderstorm There is some evidence that maximum turbulence exists at middle heights in storms 20 000 to 30 000 ft however turbulence beneath a storm is not to be minimized However the lower altitude may be affected by strong outflow winds and severe turbulence where thu...

Page 108: ...ayer of very moist air usually south or southeast in the U S in the lowest 1500 to 5000 ft above the earth s surface Moist air generates most of the energy for the storm s growth and activity Thus a thunderstorm may tend to move with the average wind flow around it but also grow toward moisture When the growth toward moisture is rapid the echo motion often appears erratic On at least one occasion ...

Page 109: ... 20 mile or larger diameter echo splits into two echoes The southernmost echo often slows turns to the right of its previous motion and becomes severe with large hail and extreme turbulence If a tornado develops it is usually at the right rear portion of the southern echo When the storm weakens it usually resumes its original direction of movement The northern echo moves left of the mean wind incr...

Page 110: ...rvation The REACT blue field shows areas where attenuation could be hiding severe weather Both the shadow and the blue field are to be avoided by 20 miles Keep the REACT blue field turned on The blue field will form fingers that point towards the stronger cells Severe Weather Avoidance Procedures Table 5 12 Configurations of Individual Echoes Northern Hemisphere Sometimes a large echo will develop...

Page 111: ... usually ranges from about 3 to 10 miles in diameter Precipitation is drawn around the low s cyclonic circulation to form the characteristic hook shape Tornadoes form within the low near hook According to statistics from the NSSL almost 60 percent of allobserved hook echoes have tornadoes associated with them A tornado is always suspected when a hook echo is seen A hook can form with no tornadoes ...

Page 112: ...arts of the cell AVOID V NOTCH BY 20 MILES A large isolated echo will sometimes have the configuration that is shown in figure 5 43 This echo is called V notch or flying eagle although some imagination may be needed by the reader to see the eagle V notch echoes are formed by the wind pattern at the leading edge left front of the echo Thunderstorm echoes with V notches are often severe containing s...

Page 113: ...supercells D The average maximum size of hail is over 2 inches 5 3 cm D The average width of the hail swath is over 12 5 miles 20 2 km D Sixty percent produce funnel clouds or tornadoes The classic pendant shape echo is shown in figure 5 44 Note the general pendant shape the hook and the steep rain gradient This storm is extremely dangerous and must be avoided STORM MOTION N AD 35706 The Classic P...

Page 114: ...adients Figure 5 45 AVOID ALL CRESCENT SHAPED ECHOES BY 20 MILES A crescent shaped echo shown in figure 5 46 with its tips pointing away from the aircraft indicates a storm cell that has attenuated the radar energy to the point where the entire storm cell is not displayed This is especially true if the trailing edge is very crisp and well defined with what appears to be a steep rain gradient When ...

Page 115: ...ho at the south end of a line of echoes is often severe and so too is the storm on the north side of a break in line Breaks frequently fill in and are particularly hazardous for this reason Breaks should be avoided unless they are 40 miles wide This is usually enough room to avoid thunderstorm hazards The above two locationsfavor severe thunderstorm formation since these storms have less competiti...

Page 116: ...e 5 47 is an example of an LEWP The most severe weather is likely at S LEWPs form solid or nearly solid lines that are dangerous to aircraft operations and disruptive to normal air traffic flow N AD 15562 R1 S Line Echo Wave Pattern LEWP Figure 5 47 The S indicates the location of the greatest hazards to aviation The next greatest probability is anywhere along the advancing usually east or southea...

Page 117: ...as shown in figure 5 48 Severe weather is most likely along the bulge and at the north end but severe weather can occur at any point along the line Bow shaped lines are particularly disruptive to aircraft operations because they are broken to solid and may accelerate to speeds in excess of 70 knots within an hour N VIP 1 VIP 3 VIP 5 S 100 mi AD 15563 R1 Bow Shaped Line of Thunderstorms Figure 5 48...

Page 118: ... variety of positions with respect to associated echoes but many of the most intense and enduring occur on the up relative windside The air rising in a tornado can contribute to a downwind area of strong echoes while the tornado itself may or may not return an echo Echo hooks and appendages though useful indexes of tornadoes are not infallible guides The appearance of a hook warns the pilot to sta...

Page 119: ...lected range Tables 5 13 and 5 5show tilt settings for maximal ground target display at selected ranges Ground Mapping Display Figure 5 49 For the low ranges 5 10 25 and 50 NM the transmitter pulsewidth is narrowed and the receiver bandwidth is widened to enhance the identification of small targets In addition the receiver STC characteristics are altered to better equalize ground target reflection...

Page 120: ...000 5 000 4 000 3 000 2 000 1 000 5 4 13 9 8 7 6 5 4 5 5 5 5 6 8 6 6 5 10 7 6 11 8 6 12 8 7 11 8 7 10 9 13 246 230 213 195 174 151 123 87 78 67 55 39 LINE OF SIGHT LIMITED REGION TILT LIMITED REGION AD 35710 TILT Setting for Maximal Ground Target Display 12 Inch Radiator Table 5 13 NOTE The line of sight distance is nominal Atmospheric conditions and terrain will offset this value ...

Page 121: ...3 5 7 12 7 2 1 0 1 2 2 2 2 1 1 0 1 0 1 1 3 1 1 5 1 0 13 5 2 1 0 0 0 11 4 1 1 9 3 2 7 246 230 213 195 174 151 123 87 78 67 55 39 LINE OF SIGHT LIMITED REGION TILT LIMITED REGION AD 35711 TILT Setting for Maximal Ground Target Display 18 Inch Radiator Table 5 14 NOTES 1 The line of sight distance is nominal Atmospheric conditions and terrain will offset this value 2 Tilt management for 24 inch radia...

Page 122: ... Precautions for Ground Operation of Airborne Weather Radar The radius R to the maximum permissible exposure level boundary is calculated for the radar system on the basis of radiator diameter rated peak power output and duty cycle The greater of the distances calculated for either the far field or near field is based on the recommendations outlined in AC No 20 68B The advisory circular is reprodu...

Page 123: ... areas Critical functions in the receiver transmitter antenna RTA are continuously monitored Each fault condition has a corresponding 2 digit fault code FC Additionally a fault name a pilot message and a line maintenance message are associated with each fault condition Faults can be accessed on the ground or while airborne The following conditions indicate that fault information is being displayed...

Page 124: ...ory is full the indicator fault storage deletes the oldest power onfault codes to make room for the newest 3 In EFIS installations some weather failures are only annunciated with an amber WX 4 In EFIS installations with TEXT FAULTS enabled the fault codes are also presented as part of the FAIL annunciation e g FAIL 13 Test Mode With TEXT FAULTS Enabled Upon entering test mode the most recent fault...

Page 125: ...are displayed 3 Strap codes indicate the installation configuration that was done at the time of installation Refer to the System Description and Installation manual for further explanation Fault Data Fields Table 7 1 The last 32 faults from the last 10 power oncycles are cycled every two antenna sweeps approximately 8 seconds 0 0 100 60 40 20 RCT T WEATHER INDICATOR 1 2 3 4 AD 46709 PILOT MESSAGE...

Page 126: ...2 shows the fault codes displayed on EFIS with text faults disabled AD 35708 R1 VOR1 VOR2 FAIL 22 HDG 319 25 15 DTRK 315 GSPD MAG1 321 TGT FMS1 130 NM V 260 KTS 50 Fault Code on EFIS Weather Display With TEXT FAULTS Disabled Figure 7 2 Radar Indication With Text Fault Enabled On Ground Figure 7 3 ...

Page 127: ...905 FPGA Firmware CRC 4846 2V ADC Reference CONTINUOUS 4903 IOP Ready IOP RADAR FAIL PULL RTA 02 4908 Int ARINC 429 Loopback POWER ON 4910 Spurious ARINC Interrupt IOP RADAR FAIL PULL RTA CONTINUOUS 4913 ARINC 429 In Coupling IOP RADAR FAIL PULL RTA POWER ON 4806 EEPROM Timer CRC FLASH CRC POWER ON 03 4811 EEPROM POC RADAR FAIL PULL RTA POWER ON 4842 Stab Trim CRC EEPROM REDO STAB TRIM REDO STAB T...

Page 128: ...ament Monitor 11 4827 Severe Magnetron MAGNETRON RADAR FAIL PULL RTA LATCHED 4829 PFN Trim Monitor HVPS MON CONTINUOUS 12 4831 Pulse Width PULSE WIDTH RADAR UNCAL PULL RTA CONTINUOUS 13 4832 Elevation Error EL POSITION TILT UNCAL CHK RADOME RTA CONTINUOUS 14 4833 Azimuth Error AZ POSITION AZIMUTH UNCAL CHK RADOME RTA CONTINUOUS 15 4836 Over Temp OVER TEMP RADAR CAUTION PULL RTA CONTINUOUS 16 4837 ...

Page 129: ...L POWER ON 27 4848 AHRS IRS Source HS 429 STAB UNCAL CHK ATT SRC INSTALLATION 30 4849 DADC Source LS 429 TURB UNCAL CHK ADC INSTALLATION 33 4852 Analog Stab Ref STAB REF STAB UNCAL CHK ATT SRC INSTALLATION 34 4853 Scan Switch Off SCAN SWITCH SCAN SWITCH CHK SWITCH INSTALLATION 35 4854 Xmit Switch Off XMIT SWITCH XMIT SWITCH CHK SWITCH INSTALLATION 4914 Invalid altitude airspeed stab strapping INVA...

Page 130: ...the next opportunity TURB UNCAL A problem has been detected with the turbulence detection hardware Assume turbulence display to be inaccurate Nonturbulence modes should be functioning properly Have the RTA checked at the next opportunity SPOKING LIKELY A problem has been detected which may cause spoking to occur Have the system checked at the next opportunity STAB UNCAL An error in the antenna pos...

Page 131: ...enance requirements All articles are returned to Reconditioned Specifications limits when they are processed through a Honeywell repair facility All articles are inspected by quality control personnel to verify proper workmanship and conformity to Type Design and to certify that the article meets all controlling documentation Reconditioned Specification criteria are on file at Honeywell facilities...

Page 132: ...l Honeywell of a possible data error in a publication Customer Response Center CRC If you do not have access to the Honeywell Online Technical Publications Web site send an e mail message or a fax or speak to a person at the CRC D E mail cas publications distribution honeywell com D Fax 1 602 822 7272 D Phone 1 877 484 2979 USA D Phone 1 602 436 0272 International Also the CRC is available if you ...

Page 133: ... Heading Reference System ANLG Analog ANSI American National Standards Institute API Antenna Position Indicator ATT Attitude AZ Azimuth BITE Built in Test Equipment BRT Brightness ccw Counterclockwise CHK Check CLR Clear CNTL Control CONFIG Configuration CRC Cyclic Redundancy Check CRT Cathode Ray Tube cw Clockwise DADC Digital Air Data Computer DSP Display EFIS Electronic Flight Instrument System...

Page 134: ... hr hour HVPS High Voltage Power Supply INHIB Inhibit IO Input Output IOP Inoperative IN Inch IRS Inertial Reference System kt kts Knot s LEWP Line Echo Wave Pattern LSS LX Lightning Sensor System MFD Multifunction Display mm millimeter MON Monitor MPEL Maximum Permissible Exposure Level NAV Navigation ND Navigation Display NM Nautical Miles NSSL National Severe Storms Laboratory NWS National Weat...

Page 135: ...can Sector SECT Sector Scan SLV Slave SPEX Spares Exchange SRC Source STAB Stabilization STC Sensitivity Timing Control TCAS Traffic Alert and Crew Alerting System TERR Terrain TGT Target TRB Turbulence TRV Total Return Vector TST Test TURB Turbulence UDI Universal Digital Interface UNCAL Uncalibration VAR Variable Variance VIP Video Integrated Processor WOW Weight on Wheels WX Weather XMIT XMTR T...

Page 136: ...ersonnel when operating airborne weather radar on the ground Cancellation AC 20 66A dated April 11 1975 is cancelled Related Reading Material Barnes and Taylor radiation Hazards and Protection London George Newnes Limited 1963 p 211 U S Department of Health Education and Welfare Public Health Service Consumer Protection and Environmental Health Service Environmental health microwaves ultraviolet r...

Page 137: ...is directed toward an absorption shield which dissipates the radio frequency energy Otherwise radiation within the enclosure can be reflected throughout the area BODY DAMAGE To prevent possible human body damage the following precautions should be taken D Personnel should never stand nearby and in front of a radar antenna which is transmitting When the antenna is not scanning the danger increases ...

Page 138: ...s are operated out of their protective cases X rays may be emitted Stray X rays may emanate from the glass envelope type pulser oscillator clipper or rectifier tubes as well as magnetrons COMBUSTIBLE MATERIALS To prevent possible fuel ignition an insulated airborne weather radar should not be operated while an aircraft is being refueled or defueled M C Beard Director of Airworthiness ...

Page 139: ...e any storm recognizable as a thunderstorm should be considered hazardous until measurements have shown it to be safe That means safe for you and your aircraft Almost any thunderstorm can spell disaster for the wrong combination of aircraft and pilot Hazards A thunderstorm packs just about every weather hazard known to aviation into one vicious bundle Although the hazards occur in numerous combina...

Page 140: ...us any cloud connected to a severe thunderstorm carries a threat of violence TURBULENCE D Potentially hazardous turbulence is present in all thunderstorms and a severe thunderstorm can destroy an aircraft Strongest turbulence within the cloud occurs with shear between updrafts and downdrafts Outside the cloud shear turbulence has been encountered several thousand feet above and 20 miles laterally ...

Page 141: ...res the amount of supercooled water decreases D Supercooled water freezes on impact with an aircraft Clear icing can occur at any altitude above the freezing level but at high levels icing from smaller droplets may be rime or mixed with rime and clear The abundance of large supercooled droplets makes clear icing very rapid between O _C and 15 _C and encounters can be frequent in a cluster of cells...

Page 142: ...ssible hail with any thunderstorm especially beneath the anvil of a large cumulonimbus Hailstones larger than one half inch in diameter can significantly damage an aircraft in a few seconds LOW CEILING AND VISIBILITY Generally visibility is near zero within a thunderstorm cloud Ceiling and visibility may also be restricted in precipitation and dust between the cloud base and the ground The restric...

Page 143: ...th a film of water and therefore act as huge water droplets giving the strongest of all echoes Numerous methods have been used in an attempt to categorize the intensity of a thunderstorm To standardize thunderstorm language between weather radar operators and pilots the use of Video Integrator Processor VIP levels is being promoted The National Weather Service NWS radar observer is able to objecti...

Page 144: ... DON TS OF THUNDERSTORM FLYING Above all remember this Never regard any thunderstorm lightly even when radar observers report the echoes are of light intensity Avoiding thunderstorms is the best policy Following are some do s and don ts of thunderstorm avoidance D Don t land or take off in the face of an approaching thunderstorm A sudden gust front of low level turbulence could cause loss of contr...

Page 145: ...ty to lessen temporary blindness from lightning D If using automatic pilot disengage altitude hold mode and speed hold mode The automatic altitude and airspeed controls will increase maneuvers of the aircraft thus increasing structural stress D If using airborne radar tilt the antenna up and down occasionally This will permit you to detect other thunderstorm activity at altitudes other than the on...

Page 146: ...ND ECHO INTENSITY ON NWS RADAR WSR 57 The frequency and severity of turbulence increases with radar reflectivity a measure of the intensity of echoes from storm targets at a standard range Derived gust velocities exceeding 2 100 feet per minute classified as severe turbulence are commonly encountered in level 3 storms In level 2 storms gusts of intensity between 1 200 and 2 100 feet per minute cla...

Page 147: ...RBORNE RADAR IS A PARTICULARLY USEFUL AID FOR PILOTS IN MAINTAINING A SAFE DISTANCE FROM SEVERE STORMS TURBULENCE ABOVE STORM TOPS Flight data shows a relationship between turbulence above storm tops and the airspeed of upper tropospheric winds WHEN THE WINDS AT STORM TOP EXCEED 100 KNOTS THERE ARE TIMES WHEN SIGNIFICANT TURBULENCE MAY BE EXPERIENCED AS MUCH AS 10 000 FEET ABOVE THE CLOUD TOPS THI...

Page 148: ...rrence of HAIL IS MUCH MORE CLEARLY IDENTIFIED WITH THE INTENSITY OF ECHOES THAN IS TURBULENCE AVOIDANCE OF MODERATE AND SEVERE STORMS SHOULD ALWAYS BE ASSOCIATED WITH THE AVOIDANCE OF DAMAGING HAIL VISUAL APPEARANCE OF STORM AND ASSOCIATED TURBULENCE WITH THEM On numerous occasions flight at NSSL have indicated that NO USEFUL CORRELATION EXISTS BETWEEN THE EXTERNAL VISUAL APPEARANCE OF THUNDERSTO...

Page 149: ...egular atmospheric overturning D Desert Areas In desert areas storms should be avoided on the same basis as described in the above paragraphs While nonstorm turbulence may in general be expected morefrequently overdesert areas during daylight hours than elsewhere THE SAME TURBULENCE CONSIDERATIONS PREVAIL IN THE VICINITY OF THUNDERSTORMS D Tropical Humid Climates When the atmosphere is moist and o...

Page 150: ...llation the pilot pushes a button to display the terrain or the terrain data isautomatically displayed when a Terrain Alert occurs SYSTEM OPERATION To display the EGPWS the weather system can be in any mode except OFF When the EGPWS is active the indicator range up and down arrows control the EGPWS display range The AZ button on the indicator is also active and the azimuth lines can be displayed o...

Page 151: ...nunciator indicates that the INHIB push button has been pushed and is active When INHIB is annunciated EGPWS is not displayed on the radar indicator and the aural annunciators do not sound NOTE The FAIL and INHIB annunciators are often incorporated into the INHIB push button D TERR Terrain The TERR annunciator indicates that the annunciator lamp power is on It does not indicate the operational sta...

Page 152: ...computer In some installations the EGPWS display on the radar indicator is manually operated It is only displayed if the pilot pushes the ON button and it is removed if the pilot pushes the ON button a second time In some installations the EGPWS display has a pop up mode in which the terrain display is automatically displayed when the EGPWS system detects a terrain alert situation The pilot can re...

Page 153: ...below the aircraft is not displayed Areas where terrain data is not available are shown in magenta Elevation of Terrain in Feet AGL Color 2000 or more above the aircraft High density red 1000 2000 above the aircraft High density yellow dot pattern 0 1000 above the aircraft Medium Density yellow Dot Pattern 0 1000 below the aircraft Medium density green dot pattern 1000 2000 below the aircraft Low ...

Page 154: ... 5 Enhanced Ground Proximity Warning System EGPWS Figure B 1 shows the EGPWS over KPHX airport at 2000 feet mean sea level heading north The terrain shows the mountains to the north of Phoenix AD 62964 EHSI Display Over KPHX Airport With the EGPWS Display Figure B 1 ...

Page 155: ... 01 REV 1 Enhanced Ground Proximity Warning System EGPWS B 6 EGPWS Test When the EGPWS is selected for display it can be tested Push the remote mounted EGPWS TEST button to display the test format shown in figure B 2 AD 63056 EGPWS Test Display Figure B 2 ...

Page 156: ... Federal Aviation Administration FAA Advisory Circulars recommended radiation safety precautions for ground operation of airborne weather radar A 1 background A 2 cancellation A 1 precautions A 2 purpose A 1 related reading material A 1 thunderstorms A 4 general A 4 hazards A 4 national severe storms laboratory NSSL thunder storm research A 11 purpose A 4 related reading material A 4 H Hidden mode...

Page 157: ...from the storm edge A 12 turbulence in relation to distance from storm core A 11 use of airborne radar A 14 visual appearance of storm and associated turbulence with them A 13 Normal operation preliminary control settings 4 1 power up procedure 4 1 radar mode ground mapping 4 6 radar mode weather 4 4 standby 4 4 test mode 4 6 color bands 4 7 dedicated radar indicator 4 7 fault code 4 7 EFIS MFD ND...

Page 158: ...26 pitch gain adjustment 5 30 pitch offset adjustment procedure 5 28 PRIMUSR 880 power up procedure 4 2 roll gain adjustment 5 29 severe weather avoidance procedures 5 60 stabilization in straight and level flight check procedure 5 21 stabilization in turns check procedure 5 23 R Radar facts additional comments 5 68 turbulence versus distance from storm core 5 68 turbulence versus distance from st...

Page 159: ...1 background A 2 cancellation A 1 precautions A 2 body damage A 2 combustible materials A 3 general A 2 purpose A 1 related reading material A 1 S Shadowing 5 40 Stabilization 5 18 pitch gain adjustment 5 30 pitch offset adjustment 5 28 roll gain adjustment 5 29 roll stabilization check 5 23 5 25 variable gain control 5 37 Stabilization precheck 5 21 System configurations 2 1 2 2 T Test mode 4 6 c...

Page 160: ...rm and associated turbulence with them A 13 purpose A 4 related reading material A 4 squall line A 4 thunderstorm flying A 9 thunderstorm research A 11 tornadoes A 5 turbulence A 5 above storm tops A 12 and altitude A 11 and echo intensity on NWS radar A 11 in relation to distance from storm core A 11 and reflectivity A 11 below cloud base A 12 in relation to distance from the storm edge A 12 visu...

Page 161: ...3 13 tilt 3 16 PULL ACT altitude compensated tilt function 3 16 WI 880 Weather radar indicator operation 3 1 BRT brightness or BRT LSS lightning sensor system 3 9 CLR TST clear test 3 9 LX lightning sensor system 3 9 OFF 3 9 SBY standby 3 9 function switch 3 3 FP flight plan 3 5 FSBY forced standby 3 5 GMAP ground mapping 3 4 OFF 3 3 rainfall rate color coding 3 4 SBY standby 3 3 TST test 3 5 WX w...

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