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GNC 255A/255B

Pilot’s Guide

Summary of Contents for GNC 255

Page 1: ...GNC 255A 255B Pilot s Guide ...

Page 2: ...nion For comments about this guide please e mail Techpubs Salem Garmin com www garmin com https fly garmin com fly garmin Except as expressly provided herein no part of this manual may be reproduced copied transmitted disseminated downloaded or stored in any storage medium for any purpose without the express written permission of Garmin Garmin hereby grants permission to download a single copy of ...

Page 3: ...ERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE STATUTORY OR OTHERWISE THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS WHICH MAY VARY FROM STATE TO STATE INNOEVENTSHALLGARMINBELIABLEFORANYINCIDENTAL SPECIAL INDIRECTORCONSEQUENTIAL DAMAGES WHETHER RESULTING FROM THE USE MISUSE OR INABILITY TO USE THE PRODUCT OR FROM DEFECTS INTHE PRODUCT SOME STATES DO NOTALLOWTHE EXCLUSION OF INCIDENTAL OR CONSEQ...

Page 4: ...ss of stored user and recent frequencies NOTE Do not use outdated database information Databases used in the system must be updated regularly in order to ensure that the information remains current Pilots using an outdated database do so entirely at their own risk NOTE All visual depictions contained within this document including screen images of the GNC 255 bezel and displays are subject to chan...

Page 5: ...Canadian installations In accordance with Canadian Radio Specifications Standard 102 RSS 102 RF field strength exposure to persons from an antenna connected to this device should be limited to 60 V m for controlled environment and 28V m for uncontrolled environment ...

Page 6: ...t correct the problem Operation of this device is subject to the following conditions 1 This device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation To obtain accessories for your unit please contact your Garmin dealer Help us better support you by completing our on line registration form today Regi...

Page 7: ... connect to the Garmin web site www garmin com or https fly garmin com fly garmin Look for the Product Registration link on the Home page Also be sure to record your serial number in the space provided If you have any questions the Garmin Product Support department may be reached Monday through Friday 7 00 AM to 7 00 PM Central Time US 913 397 8200 US Toll Free 1 866 739 5687 Canada Toll Free 1 86...

Page 8: ...vi Garmin GNC 255A 255B Pilot s Guide 190 01182 01 Rev A Record of Revisions Part Number Revision Date Description 190 01182 01 A 11 19 12 Initial release ...

Page 9: ...2 9 ENT Enter Key 1 3 1 2 10 FUNC Function Key 1 4 1 2 11 MON Monitor Key 1 4 1 3 USB Port 1 4 2 Basic Operation 2 1 2 1 Power On 2 1 2 2 Com Radio 2 1 2 2 1 Selecting a Com Frequency 2 1 2 2 2 Monitoring the Standby Com Channel 2 2 2 2 3 Saving a Com Channel 2 2 2 2 4 Com Database Look Up 2 4 2 2 5 Frequency Database Reverse Look Up 2 4 2 2 6 Emergency Channel 2 5 2 2 7 Stuck Mic 2 5 2 2 8 Remote...

Page 10: ...requencies 3 9 3 3 Nav Frequencies 3 10 3 3 1 Recent Nav Frequencies 3 10 3 3 2 Nav User Frequencies 3 11 3 3 2 1 Viewing the Nav User Frequency 3 11 3 3 2 2 Deleting the Nav User Frequency 3 11 3 3 2 3 Editing a Nav User Frequency 3 12 3 3 3 Nav Database Frequencies 3 13 3 3 4 Nav Nearest VOR 3 14 3 4 ICS Configuration 3 15 3 4 1 Adjust Intercom 3 15 3 4 2 Aux Audio 3 16 3 4 3 Intercom On Off 3 1...

Page 11: ...uide 3 6 3 Viewing Timers in the Com Display 3 24 4 Appendix 4 1 4 1 Troubleshooting 4 1 4 2 Updating the Frequency Database 4 3 4 2 1 Downloading the Frequency Database 4 3 4 2 2 Updating the GNC 255 Frequency Database 4 3 4 3 Messages 4 4 Index Index 1 ...

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Page 13: ...75 MHz in 25 kHz steps default For European operations a Com radio configuration of 8 33 kHz steps is also available The GNC 255 VHF Nav receiver operates from 108 MHz to 117 95 MHz decoding both the VHF Omni Range and Localizer navigation signals The built in Glideslope receiver will automatically tune the corresponding glideslope paired frequencies 328 MHz to 335 MHz when the localizer is tuned ...

Page 14: ...quency Annunciator Com Mode Annunciator Active Nav Frequency Standby Frequency Annunciator Figure 1 2 Com Volume and Squelch Display Description The Com radio features an automatic squelch to reject many localized noise sources You may override the squelch function by pressing the Power Com Volume Squelch knob This facilitates listening to a distant station or setting the desired volume level To o...

Page 15: ...Key Press the C N key to select the Com or Nav VLOC radio mode 1 2 6 OBS Key Press the OBS key to see the current OBS setting and graphic CDI The OBS page will be disabled if the unit is installed with an external converter 1 2 7 T F To From Key Press the T F key to toggle between the bearing TO or radial FROM the active VOR The T F page also shows Distance Speed Time information The T F key does ...

Page 16: ...NC key once displays the Function mode Pressing the FUNC key a second time exits the Function mode 1 2 11 MON Monitor Key TheMON Monitor keywillengagethemonitorfunctionwhere the Standby frequency may be monitored while still listening to the Active frequency 1 3 USB Port The USB port is used to update the frequency database in the GNC 255 NOTE Garmin recommends the use of a USB 2 0 compatible USB ...

Page 17: ...ob to change the values in one MHz increments The MHz selection range is between 118 and 136 in one MHz steps 3 Turn the SMALL knob to change the values in 25 kHz or 8 33 kHz increments The kHz selection range is between 000 and 975 kHz in 25 kHz steps or 000 and 990 kHz in 8 33 kHz steps 4 Turn the LARGE and SMALL knobs clockwise to increase and counterclockwise to decrease the frequency values S...

Page 18: ...anceled by switching to Nav mode 2 2 3 Saving a Com Channel The current Standby frequency may be saved into the Com User Frequency database from the Com display or the Com User Function The Com User Frequency database can hold up to 15 frequencies NOTE When switching from 8 33 kHz to 25 kHz mode any 8 33 kHz specific user frequencies will be deleted from the user frequency list This only affects t...

Page 19: ...ncy Type Symbol Description TWR Tower GND Ground ATIS Automatic Terminal Information Service AWS Automated Weather Observing System ATF Aerodrome Traffic Frequency ARR Arrival APPR Approach DEP Departure CLR Clearance CTAF Common Traffic Advisory Frequency FSS Flight Service Station RFS Remote Flight Service Station MF Mandatory Frequency UNI Unicom Blank None Table 2 1 Com Frequency Type List 7 A...

Page 20: ...list of waypoint types Waypoint Types with a sign will have more frequencies for the same type After selection the selected waypoint and type will be remembered for 30 minutes Turn the SMALL Knob To Select Frequency Type Figure 2 7 Database Waypoint Type Selection 4 Press ENT to copy the frequency into the Standby frequency location Press and release the FLIP FLOP key to swap the Active and Standb...

Page 21: ...z for transmit and receive regardless of the displayed frequency 2 2 7 Stuck Mic The GNC 255 helps protect you from a situation where the microphone may get stuck in the ON or Transmit position If the microphone is keyed for longer than 35 seconds the GNC 255 will return to the receive mode on the selected frequency A Stuck Mic message will display until the transmit key is released Alerts will di...

Page 22: ...ncy Figure 2 10 Nav Frequency Selection CAUTION The Identifier is determined from the database and is not the decoded Nav Identifier 4 Press and release the FLIP FLOP key to toggle the Standby frequency to the Active frequency NOTE Both Nav and Com frequencies cannot be displayed at the same time 2 3 2 Saving a Nav Channel The current Standby frequency may be saved into the Nav User Frequency data...

Page 23: ...ge DME Distance Measuring Equipment LOC Localizer ILS Instrument Landing System 01 36 Runway Heading Blank None Table 2 2 Nav Frequency Type List 2 3 3 Listening to the Nav Audio Channel Nav ident is enabled by pressing the Nav Volume knob when the Nav display is active When Nav ident is enabled the ID annunciation will appear to the left of the active Nav frequency Figure 2 13 Listening to the ID...

Page 24: ...he station 1 Press the OBS key to see the current OBS setting and graphic CDI 2 Use the LARGE and SMALL knobs to change the displayed OBS values The GNC 255 graphic CDI is shown as a graph of five dots right or left of the triangle icon Each dot indicates two degrees deflection with ten degrees full deflection to each side Fly towards the bar to be on course CDI Deflection OBS Setting To From Indi...

Page 25: ...splay If DST data is not shown pressing the T F key will show DST data in the lower part of the display Distance To Station In Nautical Miles Active Nav Frequency Station Identifier Bearing To From Station Time To Station In Hours and Minutes Ground Speed From GPS Unit In Knots Figure 2 15 DST Data Display NOTE The If both GPS and DME data sources are connected to the GNC and dashes are displayed ...

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Page 27: ...s Description Timers Count Down ENT Start Stop CLR Reset Push CRSR Settings ENT Accept Count Up ENT Start Stop CLR Reset Nav Freq Recent Freqs User Freqs Database Nearest VOR Com Freq Recent Freqs User Freqs Database Nearest Apt Nearest ACC Nearest FSS Nearest WX SYS Config Com Spacing DSPL Brt DSPL Contrast Database Info Load Database Software Ver Serial Number ICS Config Adjust Intercom Aux Audi...

Page 28: ...m Frequencies and can be accessed in this function NOTE When switching from 8 33 kHz to 25 kHz mode any 8 33 kHz specific user frequencies will be deleted from the user frequency list This only affects the user frequencies within the 8 33 kHz spectrum 1 Press FUNC to access the Functions Turn the LARGE knob to select the Com Function Turn the SMALL knob to view the Recent frequency function Then p...

Page 29: ...ncy Function Select Wpt Name Select Wpt Type Selected Frequency Figure 3 3 Viewing User Com Frequencies 2 Turn the SMALL knob to view the Com User frequency function Then press ENT Turn the SMALL knob to view the User Frequencies 3 Press and release the FLIP FLOP key to set the displayed frequency as the Active frequency 4 Press the ENT key to set the displayed frequency as the Standby frequency 3...

Page 30: ... values and turn the LARGE knob to move the cursor and then the SMALL knob to select kHz values Select User Freq Value Figure 3 6 Com User Frequency Value Selection 3 Turn the LARGE knob to select theWpt Name Turn the SMALL knob to select characters and turn the LARGE knob to move the cursor Select User Wpt Name Figure 3 7 Com User Frequency Name Selection 4 After selecting the desired characters ...

Page 31: ...ct the desired character 3 Turn the LARGE knob to move the cursor to highlight a character 4 Repeat steps 2 and 3 to complete the desired identifier and then press the ENT key 5 If available the Frequency Type will be highlighted Turn the SMALL knob to select the desired frequency Selected Identifier Press FLIP FLOP Key To Set Selected Freq As Active Selected Frequency Turn SMALL Knob To Select Fr...

Page 32: ...th the Com Frequency Function highlighted turn the SMALL knob to view the Com Nearest APT function Then press ENT 2 Turn the SMALL knob to display the available airports Press the ENT key to select the displayed airport The frequency type will be highlighted Turn the SMALL knob to select the desired frequency type 3 Then press the ENT key to set the displayed airport frequency as the Standby or pr...

Page 33: ...b To Scroll Through Available Frequencies Figure 3 12 Com Nearest ACC Frequencies 1 Press FUNC to access the Functions With the Com Frequency Function highlighted turn the SMALL knob to view the Com Nearest ACC function Then press ENT 2 Turn the SMALL knob to display the available ACCs 3 Press the ENT key to insert the highlighted frequency as the Standby frequency Or press the CLR key to return t...

Page 34: ...uencies Figure 3 13 Com Nearest FSS Frequencies 1 Press FUNC to access the Functions With the Com Frequency Function highlighted turn the SMALL knob to view the Com Nearest FSS function Then press ENT 2 Turn the SMALL knob to display the available FSS frequencies 3 Press the ENT key to insert the highlighted frequency as the Standby frequency Or press the CLR key to return to the Functions display...

Page 35: ...m Nearest Weather Frequencies 1 Press FUNC to access the Functions With the Com Frequency Function highlighted turn the SMALL knob to view the Com Nearest Weather function Then press ENT 2 Turn the SMALL knob to display the available Weather frequencies 3 Press the ENT key to insert the highlighted frequency as the Standby frequency Or press the CLR key to return to the Functions display 4 Press a...

Page 36: ...ctions Turn the LARGE knob to select the Nav Frequency Function Turn the SMALL knob to view the Recent frequency function Then press ENT Position In List Turn SMALL Knob To Select Entry Selected Frequency Press FLIP FLOP Key To Set Selected Freq As Active Press ENT Key To Set Selected Freq As Standby Active Frequency Figure 3 15 Recent Nav Frequencies 2 Turn the SMALL knob to select an Entry 1 20 ...

Page 37: ...T Key To Set Selected Freq As Standby Active Frequency Figure 3 16 Viewing User Nav Frequencies 2 Turn the SMALL knob to view the Nav User Frequencies 3 Press and release the FLIP FLOP key to set the displayed frequency as the Active frequency 4 Press the ENT key to set the displayed frequency as the Standby frequency 3 3 2 2 Deleting the Nav User Frequency 1 While viewing a Nav User frequency pre...

Page 38: ...e selected Turn the SMALL knob to select the MHz frequency value Turn the LARGE knob to move the cursor and then turn the SMALL knob to select the kHz frequency value 3 Turn the LARGE knob to select theWPT name Turn the SMALL knob to select characters and turn the LARGE knob to move the cursor Figure 3 19 Nav User Frequency Name Selection 4 After selecting the desired characters press ENT 5 Turn t...

Page 39: ... To Select Character Press the ENT Key to Save the Displayed Value Press the CLR Key To Return to the Previous Menu Figure 3 21 Nav Database Frequencies 4 Repeat steps 2 and 3 to complete the desired identifier and then press the ENT key 5 If available the Frequency Type will be highlighted Turn the SMALL knob to select the desired frequency Selected Identifier Press FLIP FLOP Key To Set Selected ...

Page 40: ... Nav Database 3 Set the selected identifier as the standby or active frequency Selected Identifier Press FLIP FLOP Key To Set Selected Freq As Active Selected Frequency Wpt Type Press ENT Key To Set Selected Freq As Standby Figure 3 25 Set Selected Frequency as Active or Standby 3 3 4 Nav Nearest VOR The GNC 255 when interfaced with an appropriate GPS receiver will report the 25 nearest VORs Turn ...

Page 41: ...he Intercom On Off function must be set to On to make the Adjust Intercom function available 1 Press FUNC to access the Functions Turn the LARGE knob to select the ICS Function Turn the SMALL knob to view the Adjust Intercom function Then press the ENT key Figure 3 27 Select the Adjust Intercom Function 2 Turn the SMALL knob to set the ICS Squelch value Then press the ENT key Turn Small Knob To Ad...

Page 42: ...gure 3 29 Select the Aux Audio Function 2 Turn the SMALL knob to turn the Aux Audio On or Off 3 Turn the LARGE knob to select the Aux Volume Turn the SMALL knob to set the value Then press the ENT key Turn Small Knob To Turn Aux On Off Press the ENT Key to Save the Displayed Value Press the CLR Key To Revert to the Previous Value Turn LARGE And Then SMALL Knob To Adjust Aux Volume Figure 3 30 Adju...

Page 43: ...ess CLR to Return to the Default Value Turn SMALL Knob To Select On or Off Figure 3 31 Turn the Intercom On Off 2 Turn the SMALL knob to set the Intercom On or Off Then press the ENT key to save the selected value 3 4 4 Speaker On Off The Speaker On Off function toggles speaker output on and off 1 Press FUNC to access the Functions Turn the LARGE knob to select the ICS Function Turn the SMALL knob...

Page 44: ...r regional requirements NOTE When switching from 8 33 kHz to 25 kHz mode any 8 33 kHz specific user frequencies will be deleted from the user frequency list This only affects the user frequencies within the 8 33 kHz spectrum 1 Press FUNC to access the Functions Turn the LARGE knob to select the SYS Function Turn the SMALL knob to view the Com spacing function Then press the ENT key Press ENT to Ac...

Page 45: ...er than normal and a value below zero means darker than normal The range can be adjusted by using the SMALL knob to adjust the value The GNC 255 will either control dimming based on the photocell or the lighting bus This is set in configuration mode during installation and is not selectable by the pilot 1 Press FUNC to access the Functions Turn the LARGE knob to select the SYS Function Turn the SM...

Page 46: ... ENT to Accept the Selected Value Turn the SMALL Knob to Select the Offset Value Press CLR to Return to the Previous Value Figure 3 35 Set Display Contrast 2 Turn the SMALL knob to set the value Then press the ENT key 3 5 4 Database Info TheDatabaseinformationfortheGNC255unitisdisplayed Thisinformation is useful when contacting Customer Support 1 Press FUNC to access the Functions Turn the LARGE k...

Page 47: ...ort on the top right corner of the GNC 255 2 Insert the USB memory device into the other end of the cable USB Cable USB Memory Device USB Port Figure 3 37 USB Update Progress 3 Press FUNC to access the Functions Turn the LARGE knob to select the SYS Function Turn the SMALL knob to view the Load Database function Then press the ENT key Figure 3 38 Database Update Display 4 Verify the database versi...

Page 48: ...lect the SYS Function Turn the SMALL knob to view the Software Version function Then press the ENT key Com Software Version Display Software Version Nav Software Version Figure 3 39 Software Versions Display 2 Press the FUNC key to return to the main menu 3 5 7 Serial Number The serial number of the GNC 255 unit is displayed This information is useful when contacting Customer Support 1 Press FUNC ...

Page 49: ...n 2 Press the ENT key to Start or Stop the timer Press the CLR key to reset the timer to the starting value Press the CURSOR knob to select a starting timer value Press ENT to Start or Stop the Timer Push the CURSOR SMALL Knob to Edit the Starting Time Value Press CLR to Reset the Timer to the Default Value The Default Starting Value Figure 3 42 Selecting the Count Down Timer 3 Turn the SMALL knob...

Page 50: ...et the Timer to 0 00 The Default Starting Value Figure 3 45 Selecting the Count Up Timer 3 6 3 Viewing Timers in the Com Display When a timer is active the timer value will be shown in the lower right corner of the Com display While both timers may be actively counting at the same time the Count Down Timer will have precedence in being shown If the Count Down Timer is paused the Count Up Timer wil...

Page 51: ... Timer reaches 0 00 it will continue counting as a Count Up value The Count Down Timer that is counting up will be highlighted A Count Up Timer will continue counting separately Count Down Timer Value Highlighted When Counting Up Figure 3 48 Count Down Timer Value Now Counting Up ...

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Page 53: ...ns etc Model No part number and serial number Software versions Description of the problem Efforts made to isolate solve the problem Garmin International Inc Aviation Products Customer Service Department 1200 East 151st Street Olathe KS 66062 3426 USA If you have any questions the Garmin AT Product Support department may be reached Monday through Friday 7 00 AM to 7 00 PM Central Time US 913 397 8...

Page 54: ...eck Mic key input connection Intercom doesn t function It can be enabled or disabled via a remote mounted switch or via the menu Check connections No voice activation or if must talk too loud Check ICS page Intercom On Off Adjust Intercom Can t change active frequency Com Radio not communicating The radio may also be in lockout mode In this case the radio would be tuned to 121 50 and the active fr...

Page 55: ...ttps fly garmin com fly garmin The following equipment is required to perform the update Windows compatible PC computer Windows 2000 XP Vista or Windows 7 recommended USB 2 0 compatible USB flash drive External USB cable Updated database obtained from the Garmin web site NOTE The data contained in the frequency database comes from government agencies Garmin accurately processes and cross validates...

Page 56: ...not communicating properly with the system Press and hold the volume knob or the external com remote transfer COM RMT XFR switch if installed this will force the com radio to 121 5 MHz Contact dealer for service COM RADIO Com overtemp or undervoltage Reducing transmitter power Com radio is in overtemp or undervoltage mode and transmitting power has been reduced to prevent damage to the com radio R...

Page 57: ...s with another source and crosscheck final approach fix crossing altitude If another glideslope source is not available for verification fly a GPS based approach Contact dealer for service GLIDESLOPE Glideslope receiver has failed The glideslope board is not communicating property with the system Fly an approach that does not use the glideslope receiver VOR LOC GPS Contact dealer for service POWER...

Page 58: ...ment key is stuck The remote com frequency increment COM CHAN UP key switch has been in pressed position for at least 30 seconds This input will now be ignored This input is not available in all installations Verify the COM CHAN UP key switch is not stuck Contact dealer for service if this message persists REMOTE KEY STUCK Com remote frequency decrement key is stuck The remote com frequency decrem...

Page 59: ...ed This input is not available in all installations Verify the NAV RMT XFR key switch is not stuck Contact dealer for service if this message persists VLOC RECEIVER Navigation receiver needs service The nav radio is reporting that it needs service The nav radio may continue to function Contact dealer for service VLOC RECEIVER Navigation receiver has failed The nav radio is not communicating proper...

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Page 61: ... 19 DST 2 9 Duplicate identifiers 3 14 E Emergency channel 2 5 Enter 1 3 F Flight Service Station 3 8 FLIP FLOP key 1 3 Fly Garmin v 3 22 4 1 4 3 Frequency monitoring 2 2 Front panel description 1 1 FSS 3 8 Functions 1 4 3 1 G Getting started 1 1 I ICS 3 15 ID 1 2 Intercom 3 17 K Knobs 1 3 L Locking screw 1 1 M Menus 1 3 Message 4 4 Monitoring 1 4 2 2 Morse code 1 1 N Nav audio 2 7 Nav database fr...

Page 62: ...ncy control 2 5 Reverse look up 2 4 Revisions vi S Saving a com channel 2 2 Saving a nav channel 2 6 Serial Number 3 22 Software version 3 22 Speaker On Off 3 17 Squelch 1 2 Stuck mic 2 5 Support v System configuration 3 18 T Timers 3 23 To From 1 3 Troubleshooting 4 1 4 4 U Updating frequency database 4 3 USB 1 4 3 21 User frequencies 3 3 3 11 V Volume 1 2 W Warranty i ...

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Page 64: ...8 Garmin Europe Ltd Liberty House Bulls Copse Road Hounsdown Business Park Southampton SO40 9RB U K Tel 44 0 870 850 1243 Fax 44 0 238 052 4004 GARMIN Corporation No 68 Zhangshu 2nd Road Xizhi Dist New Taipei City 221 Taiwan R O C Tel 886 2 2642 9199 Fax 886 2 2642 9099 Garmin Singapore Pte Ltd 46 East Coast Road 05 06 Eastgate Singapore 428766 Tel 65 63480378 Fax 65 63480278 www garmin com https ...

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