Garmin GTN 625 User manual

190-01004-02 February 2013 Revision F
GTN 625/635/650
TSO Installation Manual

190-01004-02 GTN 625/635/650 TSO Installation Manual
Rev. F Page A
©Copyright 2011-2013
Garmin International Inc., or its subsidiaries
All Rights Reserved
Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted,
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manual or revision must contain the complete text of this copyright notice and provided further that any
unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited.
SkyWatch® and Stormscope® are registered trademarks of L-3 Communications.
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At Garmin, we value your opinion. For comments about this guide, please e-mail:
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Telephone: [phone]
RECORD OF REVISIONS
Revision Revision Data Description
A 2/8/11 Initial Release
B4/27/11
Corrected plug number and added note 8 to Figure D-16.
Updated information in system functions Table 1-6. See
Current Revision Description for more details.
C 1/25/12 Added ETSO information.
D 7/31/12 Added v3.00 software functionality. See Current Revision
Description for details.
E 12/12/12 Added Helicopter and NV units. See Current Revision
Description for details.
F 2/5/13 Added v4.00 functionality. See Current Revision
Description for details.

GTN 625/635/650 TSO Installation Manual 190-01004-02
Page B Rev. F
CURRENT REVISION DESCRIPTION
Section Number Description of Change
1.5.1
Added Table1-4, Hardware Part Numbers, Table 1-5, GTN 7XX Hardware, CLD
and Software Compliance, Table 1-6, TSO and ETSO Description, and Table 1-8
CLD DO-254 Levels.
1.5.3 Added HTAWS to Table 1-9.
1.5.4 Updated deviation for TSO-C147 and ETSO-C147.
4.3 Added helicopter databases.
4.6 Added Helicopter TAWS enablement card,
5.1.1 Added note that designated pins are configurable.
5.1.2 Added note that designated pins are configurable.
5.1.4 Redefined pins 25, 26, and 27 of P1004.
5.2.4.1.2 Added GAMA Format 7, GAMA Format 8, and various pins to ARINC 429
section. Also added applicable notes.
5.2.9 Added Day/Night, Mark on Target, RP Mode, Remote Go Around, and HTAWS
Alert Acknowledgement discretes.
5.2.9.9 - 5.2.9.13 Added descriptions of Day/Night, Mark on Target, RP Mode, Remote Go Around,
and HTAWS Alert Acknowledgement discretes.
5.2.10 Added RP Mode Annunciate to Discrete Outputs table.
5.2.10.20 Added RP Mode Annunciate description.
6.6.1 Added Radar Altimeter to Data In Selections table.
Added GAMA Format 7 and GAMA Format 8 to Data Out Selections table.
6.6.7 Added new section and subsections, “Enhanced Lighting Configuration.”
6.6.10
Added new subheading and description, “Airframe Type.”
Added new subheading and description, “Radio Altimeter Input.”
Added new subheading and description, “Enhanced Lighting Mode.”
Added new subheading and description, “Pilot Position.”
Added new subheading and description, “Crossfill Status Alert.”
6.6.13 Added new section, “Discrete Configuration.”
6.6.14 Added new section, “Waypoint Configuration.”
6.7.1 Rewrote section to include HTAWS.
6.10.9 Added statement about enhanced lighting configuration to lighting bus interface
check.
6.11.6 Rewrote section to include HTAWS.
Appendix D
The following figures had a note added to explain that the default discrete function
for the noted pin(s) is shown: D-6 through D-8, D-13, and D-25 through D-31.
Updated Figure D-4 for enhanced lighting.
Added HTAWS to Figure D-27.
Added new figure (Figure D-33), “GTN-Radar Altimeter Interconnect.”

190-01004-02 GTN 625/635/650 TSO Installation Manual
Rev. F Page C
DOCUMENT PAGINATION
Section Pagination
Table of Contents i - xii
Section 1 1-1 through 1-34
Section 2 2-1 through 2-2
Section 3 3-1 through 3-12
Section 4 4-1 through 4-14
Section 5 5-1 through 5-30
Section 6 6-1 through 6-74
Section 7 7-1 through 7-2
Appendix A A-1 through A-2
Appendix B B-1 through B-10
Appendix C C-1 through C-8
Appendix D D-1 through D-46

GTN 625/635/650 TSO Installation Manual 190-01004-02
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190-01004-02 GTN 625/635/650 TSO Installation Manual
Rev. F Page i
INFORMATION SUBJECT TO EXPORT CONTROL LAWS
This document may contain information which is subject to the Export Administration Regulations
("EAR") issued by the United States Department of Commerce (15 CFR, Chapter VII, Subchapter C) and
which may not be exported, released, or disclosed to foreign nationals inside or outside of the United States
without first obtaining an export license. A violation of the EAR may be subject to a penalty of up to 10
years imprisonment and a fine of up to $1,000,000 under Section 2410 of the Export Administration Act of
1979. Include this notice with any reproduced portion of this document.
DEFINITIONS OF WARNINGS, CAUTIONS, AND NOTES
WARNING
Warnings are used to bring to the installer’s immediate attention that not only
damage to the equipment but personal injury may occur if the instruction is
disregarded.
CAUTION
Cautions are used to alert the individual that damage to equipment may result if
the procedural step is not followed to the letter.
NOTE
Notes are used to expand and explain the preceding step and provide further
understanding of the reason for the particular operation.

GTN 625/635/650 TSO Installation Manual 190-01004-02
Page ii Rev. F
WARNING
This product, its packaging, and its components contain chemicals known to the State of
California to cause cancer, birth defects, or reproductive harm. This notice is being
provided in accordance with California's Proposition 65. If you have any questions or
would like additional information, please refer to our web site at www.garmin.com/
prop65.
WARNING
Perchlorate Material – special handling may apply, See www.dtsc.ca.gov./
hazardouswaste/perchlorate.
WARNING
This product contains a lithium battery that must be recycled or disposed of properly.
Battery replacement and removal must be performed by professional services.
CAUTION
To avoid damage to the GTN, take precautions to prevent Electro-Static Discharge (ESD)
when handling the GTN, connectors, fan, and associated wiring. ESD damage can be
prevented by touching an object that is of the same electrical potential as the GTN before
handling the GTN itself.
CAUTION
The GTN 625, GTN 635 and GTN 650 has a display that is coated with a special anti-
reflective coating and is very sensitive to waxes and abrasive cleaners. CLEANERS
CONTAINING AMMONIA WILL HARM THE ANTI-REFLECTIVE COATING. It is very
important to clean the display using a microfiber cloth or with a clean, lint-free cloth and
an eyeglass lens cleaner that is safe for anti-reflective coatings.
NOTE
Garmin recommends installation of the GTN 625, GTN 635 and/or GTN 650 by a Garmin-
authorized installer. To the extent allowable by law, Garmin will not be liable for damages
resulting from the improper or negligent installation of the GTN unit by anyone other than
a Garmin-authorized installer. It is the responsibility of the installer to ensure the latest
revision of the applicable installation manual is used for any installation of a Garmin
product. For questions, or to request the latest revision of a Garmin installation manual,
please contact Garmin Aviation Product Support at 866-739-5687.

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1 GENERAL DESCRIPTION..........................................................................................................1-1
1.1 Introduction ................................................................................................................................1-1
1.2 Equipment Description...............................................................................................................1-2
1.3 Technical Specifications ............................................................................................................1-3
1.3.1 Physical Characteristics ......................................................................................................1-3
1.3.2 General Specifications ........................................................................................................1-4
1.3.3 Display ................................................................................................................................1-4
1.3.4 GTN GPS/SBAS Specifications .........................................................................................1-5
1.3.5 COM Specifications (GTN 635/650 Only) ........................................................................1-6
1.3.6 VOR Specifications (GTN 650 Only) ...............................................................................1-8
1.3.7 LOC Specifications (GTN 650 Only) .................................................................................1-9
1.3.8 Glideslope Specifications (GTN 650 Only) .....................................................................1-10
1.3.9 GPS/WAAS Antenna Requirements ................................................................................1-12
1.4 License Requirements ..............................................................................................................1-13
1.5 Regulatory Compliance............................................................................................................1-14
1.5.1 TSO Authorization and Advisory Circular References ....................................................1-14
1.5.2 Non-TSO Functions ..........................................................................................................1-21
1.5.3 TSO System Functions and Software Levels ...................................................................1-21
1.5.4 TSO/ETSO Deviations .....................................................................................................1-23
1.5.5 FCC Grant of Equipment Authorization ...........................................................................1-27
1.5.6 AFM/AFMS/POH Considerations ....................................................................................1-27
1.6 GTN Databases ........................................................................................................................1-31
1.6.1 Basemap Database ............................................................................................................1-31
1.6.2 Navigation Database .........................................................................................................1-31
1.6.3 FliteCharts® Database (GTN 725/750 Only) ...................................................................1-32
1.6.4 ChartView™ Database (GTN 725/750 Only) ..................................................................1-32
1.6.5 SafeTaxi® Database .........................................................................................................1-32
1.6.6 Terrain Database ...............................................................................................................1-32
1.6.7 Obstacle Database .............................................................................................................1-33
1.7 Fault Detection and Exclusion (FDE) ......................................................................................1-33
1.8 Aviation Limited Warranty ......................................................................................................1-34
2 LIMITATIONS...............................................................................................................................2-1
2.1 Installation..................................................................................................................................2-1
2.1.1 GPS Antenna ......................................................................................................................2-1
2.1.2 Helicopter Installation ........................................................................................................2-1
2.2 Aircraft Radio.............................................................................................................................2-1
2.3 Weather Products .......................................................................................................................2-1
3 INSTALLATION OVERVIEW....................................................................................................3-1
3.1 Introduction ................................................................................................................................3-1
3.2 Minimum System Configuration................................................................................................3-1
3.2.1 VFR GPS Installation .........................................................................................................3-1
3.2.2 IFR Installation of a GTN 625/635 .....................................................................................3-1
3.2.3 IFR Installation of a GTN 650 ............................................................................................3-2
3.3 External Sensors.........................................................................................................................3-2
3.3.1 Multiple Uncorrected Pressure Altitude Sources ...............................................................3-2
3.3.2 Multiple Baro-Corrected Altitude Sources .........................................................................3-3
3.3.3 Multiple Heading Sources ..................................................................................................3-3
3.3.4 Multiple Indicated Airspeed Sources ..................................................................................3-3
3.3.5 Multiple True Airspeed Sources .........................................................................................3-4
3.3.6 Multiple VLOC Selected Course Sources ..........................................................................3-4

GTN 625/635/650 TSO Installation Manual 190-01004-02
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3.3.7 GPS Selected Course Sources ............................................................................................3-4
3.3.8 Total Air Temperature Sources ..........................................................................................3-4
3.3.9 Static Air Temperature Sources ..........................................................................................3-5
3.4 GDL 88 Installation Considerations...........................................................................................3-5
3.5 Antenna Considerations .............................................................................................................3-6
3.5.1 GPS Antenna Location .......................................................................................................3-6
3.5.2 COM Antenna Location .....................................................................................................3-7
3.5.3 VOR/LOC Antenna Location .............................................................................................3-9
3.5.4 Glideslope Antenna Location .............................................................................................3-9
3.5.5 Electrical Bonding ..............................................................................................................3-9
3.5.6 Interference of GPS ............................................................................................................3-9
3.6 GTN 625/635/650 Mounting Considerations...........................................................................3-10
3.7 Cabling and Wiring Considerations .........................................................................................3-10
3.8 Air Circulation and Cooling.....................................................................................................3-11
3.9 Compass Safe Distance ............................................................................................................3-11
4 INSTALLATION PROCEDURES ...............................................................................................4-1
4.1 Unit and Accessories..................................................................................................................4-1
4.2 Optional Accessories..................................................................................................................4-3
4.2.1 GPS Antenna Options .........................................................................................................4-3
4.3 Database Options........................................................................................................................4-4
4.4 Miscellaneous Options ...............................................................................................................4-4
4.5 Optional Reference Material ......................................................................................................4-5
4.6 Enablement Cards ......................................................................................................................4-5
4.7 Installation Materials Required but not Supplied.......................................................................4-6
4.7.1 Accessories Required but not Supplied ..............................................................................4-6
4.7.2 Materials Required but not Supplied (New Installations Only) .........................................4-6
4.7.3 Optional Annunciation Panels ............................................................................................4-7
4.8 Special Tools Required ..............................................................................................................4-8
4.9 Coaxial Cable Installation ..........................................................................................................4-9
4.10 Equipment Mounting................................................................................................................4-11
4.10.1 Rack Installation ...............................................................................................................4-11
4.10.2 GTN Unit Insertion and Removal .....................................................................................4-11
4.10.3 Unit Replacement .............................................................................................................4-11
4.11 Antenna Installation and Connections......................................................................................4-12
4.11.1 GPS Antenna ....................................................................................................................4-12
4.11.2 COM Antenna (GTN 635/650 Only) ................................................................................4-13
4.11.3 NAV Antenna (GTN 650 Only) .......................................................................................4-13
5 CONNECTOR PINOUT INFORMATION.................................................................................5-1
5.1 Pin Function List ........................................................................................................................5-1
5.1.1 P1001 Main Connector – Main Board ................................................................................5-1
5.1.2 P1002 Connector ................................................................................................................5-4
5.1.3 P1003 COM Connector (GTN 635/650 Only) ...................................................................5-5
5.1.4 P1004 NAV Connector (GTN 650 Only) ...........................................................................5-7
5.2 Power, Lighting, And Antennas.................................................................................................5-9
5.2.1 Power ..................................................................................................................................5-9
5.2.2 Lighting Bus .....................................................................................................................5-10
5.2.3 Antennas ...........................................................................................................................5-10
5.2.4 Serial Data ........................................................................................................................5-11
5.2.5 Ethernet (HSDB) ..............................................................................................................5-16
5.2.6 Main Audio Output ...........................................................................................................5-16

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5.2.7 Main Indicator ..................................................................................................................5-16
5.2.8 OBS ...................................................................................................................................5-18
5.2.9 Discrete Inputs ..................................................................................................................5-18
5.2.10 Discrete Outputs ...............................................................................................................5-21
5.2.11 TIME MARK OUT ..........................................................................................................5-23
5.2.12 COM Audio (GTN 635/650 Only) ...................................................................................5-24
5.2.13 COM Discrete Inputs (GTN 650 Only) ............................................................................5-25
5.2.14 VOR/ILS Audio (GTN 650 Only) ....................................................................................5-25
5.2.15 VOR/ILS Discrete Inputs (GTN 650 Only) ......................................................................5-26
5.2.16 VOR/ILS Indicator (GTN 650 Only) ...............................................................................5-26
5.2.17 RMI/OBI (GTN 650 Only) ...............................................................................................5-28
5.2.18 DME Tuning (GTN 650 Only) .........................................................................................5-29
6 POST INSTALLATION CONFIGURATION AND CHECKOUT PROCEDURES..............6-1
6.1 System Configuration Overview................................................................................................6-1
6.2 Mounting, Wiring, and Power Checks .......................................................................................6-1
6.3 Connector Engagement Check ...................................................................................................6-2
6.4 Configuration Mode Operations.................................................................................................6-2
6.5 System Information Page ...........................................................................................................6-3
6.6 GTN Setup Page.........................................................................................................................6-3
6.6.1 ARINC 429 Configuration Page .........................................................................................6-3
6.6.2 RS-232 Configuration Page ................................................................................................6-7
6.6.3 HSDB (Ethernet) Configuration Page ..............................................................................6-11
6.6.4 Interfaced Equipment Page ...............................................................................................6-11
6.6.5 Main Indicator (Analog) Configuration Page ...................................................................6-12
6.6.6 Lighting Configuration Page ............................................................................................6-13
6.6.7 Enhanced Lighting Configuration Page (software version 4.00 or later) .........................6-15
6.6.8 Audio Configuration Page ................................................................................................6-19
6.6.9 Traffic Configuration Page ...............................................................................................6-19
6.6.10 Main System Configuration Page .....................................................................................6-20
6.6.11 COM Configuration Page (GTN 635/650 Only) ..............................................................6-23
6.6.12 VOR/LOC/GS Configuration Page (GTN 650 Only) ......................................................6-24
6.6.13 Discrete Configuration (software version 4.00 or later) ...................................................6-26
6.6.14 Waypoint Configuration (software version 4.00 or later) ................................................6-27
6.7 GTN Options Page ...................................................................................................................6-28
6.7.1 Terrain (TAWS/HTAWS) Configuration Page ................................................................6-29
6.7.2 COM Transmit Power Configuration Page ......................................................................6-31
6.7.3 Flight Simulator ................................................................................................................6-31
6.8 GTN Diagnostics Page .............................................................................................................6-32
6.8.1 ARINC Inputs Page ..........................................................................................................6-32
6.8.2 Serial Inputs Page .............................................................................................................6-32
6.8.3 Discrete Pages ...................................................................................................................6-32
6.8.4 HSDB (Ethernet) Page ......................................................................................................6-32
6.8.5 Main Indicator (Analog) Diagnostics Page ......................................................................6-32
6.8.6 Analog Inputs Page ...........................................................................................................6-33
6.8.7 Power Statistics Page ........................................................................................................6-33
6.8.8 WAAS Diagnostics Page ..................................................................................................6-33
6.8.9 Temperatures Page ............................................................................................................6-33
6.8.10 Error Log Page ..................................................................................................................6-33
6.8.11 Main Data Inputs Page ......................................................................................................6-33
6.8.12 VOR/ILS Indicator (Analog) Page ...................................................................................6-33

GTN 625/635/650 TSO Installation Manual 190-01004-02
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6.8.13 Clear Config Module ........................................................................................................6-33
6.9 External Systems ......................................................................................................................6-34
6.9.1 GDL 69/69A Interface Check ...........................................................................................6-34
6.9.2 Stormscope® Page ............................................................................................................6-35
6.9.3 Traffic Test Page ...............................................................................................................6-36
6.9.4 GAD 42 Configuration .....................................................................................................6-37
6.9.5 Remote Transponder Configuration (GTX 32 or GTX 33 Only) .....................................6-37
6.9.6 GDL 88 Page (software version 3.00 or later) ..................................................................6-49
6.9.7 GSR 56 Page (software version 3.00 or later) ..................................................................6-51
6.10 Ground Checks (Configuration Mode) ....................................................................................6-52
6.10.1 Main Indicator Check (Analog Only) ...............................................................................6-52
6.10.2 VOR/ILS Indicator (Analog) Diagnostics ........................................................................6-52
6.10.3 Discrete Inputs Checkout ..................................................................................................6-53
6.10.4 Discrete Outputs Checkout ...............................................................................................6-53
6.10.5 HSDB Provisional Wiring Checkout ................................................................................6-53
6.10.6 Crossfill Check (If Dual GTNs Installed) .........................................................................6-54
6.10.7 TAWS/HTAWS Audio Check (For Units with TAWS/HTAWS Only) ..........................6-54
6.10.8 GAD 42 Interface Check ..................................................................................................6-55
6.10.9 Lighting Bus Interface Check ...........................................................................................6-55
6.10.10 Altitude Encoder or Air Data Computer Check ...............................................................6-56
6.10.11 AHRS/IRU Interface Check .............................................................................................6-56
6.11 Ground Checks (Normal Mode).................................................................................................6-57
6.11.1 Display of Self-Test Data .................................................................................................6-57
6.11.2 Signal Acquisition Check .................................................................................................6-58
6.11.3 VHF COM Interference Check .........................................................................................6-58
6.11.4 VHF NAV Checkout (GTN 650 Only) ............................................................................6-60
6.11.5 VHF COM Checkout (GTN 635/650 Only) .....................................................................6-60
6.11.6 TAWS/HTAWS System Check (For Units with TAWS/HTAWS Only) ........................6-60
6.12 Interface Checkout ...................................................................................................................6-61
6.12.1 Honeywell (Bendix/King) EFS40/50 Interface Check .....................................................6-61
6.12.2 Sandel SN 3308 Interface Check ......................................................................................6-61
6.12.3 EHSI Deviation Scaling (If HSI/CDI Is Driven by the GTN Via Serial Data) ................6-64
6.12.4 ARINC 429 Traffic System Interface Check ....................................................................6-65
6.12.5 Stormscope® Interface Check ..........................................................................................6-65
6.12.6 GMX 200/MX20 Interface Check ....................................................................................6-65
6.12.7 GDL 69/69A Interface Check ...........................................................................................6-65
6.12.8 VOR RMI/OBI Interface Check (GTN 650 Only) ...........................................................6-66
6.12.9 DME Interface Check (GTN 650 Only) ...........................................................................6-66
6.12.10 Magnetic Compass Check ................................................................................................6-66
6.12.11 EMI/RFI Check .................................................................................................................6-67
6.12.12 GDL 88 Interface Check ...................................................................................................6-67
6.12.13 GSR 56 Iridium® Check ..................................................................................................6-68
6.12.14 Ryan TCAD Traffic System Interface Check ...................................................................6-68
6.12.15 TIS (Garmin GTX 33/330) Interface Test ........................................................................6-69
6.12.16 Transponder Interface Check ............................................................................................6-69
6.13 Flight Checks............................................................................................................................6-70
6.13.1 GPS Flight Check .............................................................................................................6-70
6.13.2 VHF COM Flight Check (GTN 635/650 Only) ...............................................................6-70
6.13.3 VOR Flight Check (GTN 650 Only) ................................................................................6-70
6.13.4 ILS Flight Check (GTN 650) ............................................................................................6-71

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6.13.5 Autopilot Flight Check .....................................................................................................6-71
6.13.6 TAWS/HTAWS Audio Flight Check (TAWS/HTAWS-equipped units only) ................6-71
6.14 Database Check ........................................................................................................................6-71
6.15 Data Card Replacement............................................................................................................6-72
6.16 Software Loading .....................................................................................................................6-72
6.16.1 Creating a GTN Software Loader Card ............................................................................6-72
6.16.2 GTN Software Loading ....................................................................................................6-73
6.17 Documentation Checks ............................................................................................................6-74
6.17.1 Airplane Flight Manual Supplement ................................................................................6-74
7 PERIODIC MAINTENANCE.......................................................................................................7-1
7.1 Equipment Calibration ...............................................................................................................7-1
7.2 VOR Checks...............................................................................................................................7-1
7.3 Cleaning .....................................................................................................................................7-1
7.4 Battery Replacement ..................................................................................................................7-1
APPENDIX A ENVIRONMENTAL QUALIFICATION FORM .................................................A-1
APPENDIX B GTN DATA FORMAT ............................................................................................. B-1
B.1 RS-232 AVIATION DATA FORMAT ....................................................................................... B-1
B.1.1 Electrical Interface ................................................................................................................ B-1
B.1.2 General Output Format ......................................................................................................... B-1
B.1.3 Aviation Output Sentence Type 1 ......................................................................................... B-1
B.1.4 Aviation Output Sentence Type 2 ......................................................................................... B-3
B.2 GTN RS-232 FUEL/AIR DATA INPUT FORMAT .................................................................. B-5
B.2.1 Electrical Interface ................................................................................................................ B-5
B.2.2 Altitude Format 3 Sentence ................................................................................................... B-5
B.2.3 Altitude Format 1 Sentence .................................................................................................. B-5
B.2.4 Fuel Format 2 Sentence ......................................................................................................... B-6
B.2.5 Fuel Format 1 Sentence ........................................................................................................ B-6
B.2.6 FADC Format 1/Airdata Format 1 Sentence ....................................................................... B-7
APPENDIX C MECHANICAL DRAWINGS .................................................................................C-1
C.1 DRAWING LIST ........................................................................................................................ C-1
APPENDIX D INTERCONNECT DIAGRAMS .............................................................................D-1
D.1 DRAWING LIST ........................................................................................................................D-1

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Figure 3-1. GPS Antenna Installation Considerations ..........................................................................3-8
Figure 4-1. Coaxial Cable Installation ...................................................................................................4-9
Figure 6-1. Configuration Mode Page ...................................................................................................6-2
Figure 6-2. System Information Page ....................................................................................................6-3
Figure 6-3. GTN Setup Page .................................................................................................................6-3
Figure 6-4. ARINC 429 Configuration Page .........................................................................................6-3
Figure 6-5. RS-232 Configuration Page ................................................................................................6-7
Figure 6-6. HSDB Port Utilization Page .............................................................................................6-11
Figure 6-7. Interfaced Equipment Page ...............................................................................................6-11
Figure 6-8. Main Indicator (Analog) Configuration Page ...................................................................6-12
Figure 6-9. Lighting Configuration Page ............................................................................................6-13
Figure 6-10. Photocell Configuration Page ...........................................................................................6-14
Figure 6-11. Lighting Bus Configuration Page .....................................................................................6-14
Figure 6-12. Enhanced Lighting Configuration Page ............................................................................6-15
Figure 6-13. Enhanced Lighting Configuration - Source Settings Page ...............................................6-16
Figure 6-14. Enhanced Lighting Configuration - Day Mode Operation ...............................................6-17
Figure 6-15. Enhanced Lighting Configuration - Display-Day Mode Page .........................................6-18
Figure 6-16. Enhanced Lighting Configuration - Night Mode Operation Page ....................................6-18
Figure 6-17. Audio Configuration Page ................................................................................................6-19
Figure 6-18. Select Test Sound Page .....................................................................................................6-19
Figure 6-19. Traffic Configuration Page ...............................................................................................6-19
Figure 6-20. Main System Configuration Page .....................................................................................6-20
Figure 6-21. Measurement of GPS Antenna Vertical Offset ................................................................6-21
Figure 6-22. COM Configuration Page .................................................................................................6-23
Figure 6-23. VOR/LOC/GS Configuration Page ..................................................................................6-24
Figure 6-24. Discrete Configuration Page .............................................................................................6-26
Figure 6-25. Discrete Configuration Menu ...........................................................................................6-26
Figure 6-26. Waypoint Configuration Page ..........................................................................................6-27
Figure 6-27. GTN Options Page ............................................................................................................6-28
Figure 6-28. Terrain Configuration (Fixed Wing Installations) ............................................................6-29
Figure 6-29. Terrain Configuration Page (Rotorcraft Installations) ......................................................6-29
Figure 6-30. Audio Clips Page ..............................................................................................................6-30
Figure 6-31. COM Transmit Power Configuration Page ......................................................................6-31
Figure 6-32. GTN Diagnostics Page .....................................................................................................6-32
Figure 6-33. External Systems Page ......................................................................................................6-34
Figure 6-34. GDL 69/69A Configuration Page .....................................................................................6-34
Figure 6-35. Stormscope Page ...............................................................................................................6-35
Figure 6-36. Stormscope Configuration Page .......................................................................................6-35
Figure 6-37. Stormscope Test Page .......................................................................................................6-35
Figure 6-38. Stormscope Test Menu Page ............................................................................................6-35
Figure 6-39. Traffic Test Page ...............................................................................................................6-36
Figure 6-40. GAD 42 Configuration Page ............................................................................................6-37
Figure 6-41. XPDR Configuration Page ...............................................................................................6-37
Figure 6-42. XPDR Input/Outputs Page ................................................................................................6-37
Figure 6-43. Remote XPDR Configuration Page ..................................................................................6-45
Figure 6-44. Microsoft Windows Calculator .........................................................................................6-47
Figure 6-45. XPDR Audio Configuration Page ....................................................................................6-48
Figure 6-46. GDL 88 Page ....................................................................................................................6-49
Figure 6-47. GDL 88 Diagnostics Page ................................................................................................6-49
Figure 6-48. GDL 88 Configuration Page .............................................................................................6-50

190-01004-02 GTN 625/635/650 TSO Installation Manual
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Figure 6-49. GSR 56 Page .....................................................................................................................6-51
Figure 6-50. Main Indicator (Analog) Diagnostics Page ......................................................................6-52
Figure 6-51. VOR/ILS Indicator (Analog) Diagnostics Page ...............................................................6-52
Figure 6-52. Discrete Inputs Page .........................................................................................................6-53
Figure 6-53. Discrete Outputs Page .......................................................................................................6-53
Figure 6-54. HSDB Port Status Page ....................................................................................................6-53
Figure 6-55. Audio Configuration Page ................................................................................................6-54
Figure 6-56. GAD 42 Configuration Page ............................................................................................6-55
Figure 6-57. Lighting Configuration Page ............................................................................................6-55
Figure 6-58. Main Data Inputs Page ......................................................................................................6-56
Figure 6-59. Updates Page ....................................................................................................................6-73
Figure C-1. GTN 625/635/650 CG and Mounting Rack Dimensions .................................................. C-3
Figure C-2. GTN 625/635/650 Mounting Rack Installation ................................................................. C-4
Figure C-3. GTN 625/635/650 Recommended Panel Cutout Dimensions ........................................... C-5
Figure C-4. GTN 625/635/650 Mounting Rack and Tab Alignment Detail ......................................... C-6
Figure C-5. GTN 6XX Connector Layout Detail – Rear View ............................................................ C-7
Figure D-1. GTN System Interface Diagram ........................................................................................D-3
Figure D-2. GTN 650 Typical Installation ............................................................................................D-4
Figure D-3. GTN 625 Typical Installation ............................................................................................D-6
Figure D-4. GTN 6XX Power Lighting Configuration Interconnect ....................................................D-8
Figure D-5. GTN 6XX – Antenna Interconnect ....................................................................................D-9
Figure D-6. GTN 6XX – Main Indicator Interconnect .......................................................................D-12
Figure D-7. GTN 6XX - Autopilot Interconnect .................................................................................D-13
Figure D-8. GTN 6XX - Traffic Interconnect .....................................................................................D-14
Figure D-9. GTN 6XX - Transponder Interconnect ............................................................................D-15
Figure D-10. Dual GTN to Single GDU Interconnect ..........................................................................D-19
Figure D-11. GTN 6XX - ARINC 429 EFIS Interconnect ...................................................................D-20
Figure D-12. GTN - GDL 69/69A Interconnect ....................................................................................D-22
Figure D-13. Audio Panel Interconnect ................................................................................................D-23
Figure D-14. GTN 6XX - Air Data/IRU/AHRS RS-232 Interconnect .................................................D-25
Figure D-15. GTN 6XX - Air Data/IRU/AHRS ARINC 429 Interconnect ..........................................D-27
Figure D-16. GTN 6XX - GAD 42 Interconnect ..................................................................................D-28
Figure D-17. VOR/ILS Indicator Interconnect .....................................................................................D-29
Figure D-18. GTN - RMI OBI Interconnect .........................................................................................D-30
Figure D-19. GTN 6XX – WX-500 Interconnect .................................................................................D-31
Figure D-20. GTN 650 - DME Interconnect .........................................................................................D-32
Figure D-21. GTN 650 – Remote DME Interconnect ...........................................................................D-33
Figure D-22. Parallel 2 of 5 DME Tuning ............................................................................................D-34
Figure D-23. Parallel Slip Code DME Tuning Interconnect .................................................................D-35
Figure D-24. Reserved ..........................................................................................................................D-36
Figure D-25. GPS Annunciator Interconnect ........................................................................................D-37
Figure D-26. NAV Source Select Annunciator Interconnect ................................................................D-38
Figure D-27. TAWS/HTAWS Interconnect ..........................................................................................D-39
Figure D-28. Switches Interconnect ......................................................................................................D-40
Figure D-29. GTN 6XX - GDL 88/88D - Single GTN Installation Interconnect .................................D-41
Figure D-30. GTN 6XX - GDL 88/88D - Dual GTN Installation Interconnect ...................................D-42
Figure D-31. GTN 6XX - GSR 56 Interconnect ...................................................................................D-43
Figure D-32. Reserved ..........................................................................................................................D-44
Figure D-33. GTN 6XX - Radar Altimeter Interconnect ......................................................................D-45

GTN 625/635/650 TSO Installation Manual 190-01004-02
Page x Rev. F
Table 1-1. GTN Units ...........................................................................................................................1-1
Table 1-2. GTN Current Specifications ..............................................................................................1-11
Table 1-3. Approved GPS/WAAS Antennas ......................................................................................1-12
Table 1-4. Hardware Part Numbers ....................................................................................................1-15
Table 1-5. GTN 6XX Hardware, CLD, and Software Compliance ....................................................1-16
Table 1-6. TSO and ETSO Description ..............................................................................................1-20
Table 1-7. Non-TSO Functions...........................................................................................................1-21
Table 1-8. CLD DO-254 Levels..........................................................................................................1-21
Table 1-9. System Functions...............................................................................................................1-22
Table 4-1. Catalog Part Numbers..........................................................................................................4-1
Table 4-2. Standard Kit Accessories.....................................................................................................4-2
Table 4-3. Replacement Fan Parts ........................................................................................................4-2
Table 4-4. Recommended Crimp Tools (or Equivalent).......................................................................4-8
Table 4-5. Socket Contact Part Numbers............................................................................................4-10
Table B-1. Type 1 Output Sentence Format .........................................................................................B-2
Table B-2. Type 2 Output Sentence Format .........................................................................................B-4

190-01004-02 GTN 625/635/650 TSO Installation Manual
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GTN 625/635/650 HARDWARE MOD LEVEL HISTORY
The following table identifies hardware modification (Mod) Levels for the GTN 625, GTN 635 and 
GTN 650. Mod Levels are listed with the associated service bulletin number, service bulletin date, and the
purpose of the modification. The table is current at the time of publication of this manual (see date on front
cover) and is subject to change without notice. Authorized Garmin Sales and Service Centers are
encouraged to access the most up-to-date bulletin and advisory information on the Garmin Dealer
Resource web site at www.garmin.com using their Garmin-provided user name and password.
MOD
LEVEL
SERVICE
BULLETIN
NUMBER
SERVICE
BULLETIN
DATE
PURPOSE OF MODIFICATION
1 SB 1203 March 8,
2012
Some GTN 650 and GTN 750 units require upgrade or
MOD 1 marking of previous upgrade to improve the reli-
ability of the VHF navigation receiver.
2N/A N/A
In installations with insufficient antenna isolation, some
GTN 635/650 and GTN 750 units require upgrade to
MOD 2 to prevent squelch from breaking when the COM
receiver is overloaded, or to keep the transmitting COM
from causing the GTN's VOR receiver from flagging.
3N/A N/A
Modification for installations that need to meet RTCA/
DO-160F, Section 8, Category U, Curve G vibration (typi-
cally helicopter).

GTN 625/635/650 TSO Installation Manual 190-01004-02
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190-01004-02 GTN 625/635/650 TSO Installation Manual
Rev. F Page 1-1
1 GENERAL DESCRIPTION
1.1 Introduction
This manual is intended to provide physical, mechanical and electrical information for use in the planning
and design of an installation of the GTN units into an aircraft. It is not a substitute for an approved
airframe-specific maintenance manual, installation design drawing, or complete installation data package.
Attempting to install equipment by reference to this manual alone and without first planning or designing
an installation specific to your aircraft is not recommended. The content of this manual assumes use by
competent and qualified avionics engineering personnel and/or avionics installation specialists using
standard aviation maintenance practices in accordance with Title 14 of the Code of Federal Regulations
and other relevant accepted practices, and is not intended for use by individuals who lack the competencies
set forth above. Refer to Section 2, Limitations, for additional information and other considerations.
NOTE
Except where specifically noted, references made to GTN will equally apply to the 
GTN 625, GTN 635, and GTN 650. All screen shots used in this document are current at
the time of publication. Screen shots are intended to provide visual reference only. All
information depicted in screen shots, including software file names, versions, and part
numbers, is subject to change and may not be up to date.
Table 1-1. GTN Units
Model Part Number Color Comment
GTN 625 011-02254-00 BLACK
GTN 635 011-02255-00 BLACK
GTN 650
011-02256-00 BLACK
011-02256-50 GRAY
011-02256-A0 BLACK NVIS-B compatible

GTN 625/635/650 TSO Installation Manual 190-01004-02
Page 1-2 Rev. F
1.2 Equipment Description
The GTN 625 is a GPS/SBAS unit and may be approved for IFR en route, terminal, non-precision, and
precision approach operations. The GTN 625 meets the requirements of the TSO specified in Table 1-6.
The GTN 635 includes all of the features of the GTN 625 in addition to an airborne VHF communications
transceiver. The GTN 635 meets the requirements of the TSO specified in Table 1-6.
The GTN 650 includes all of the features of the GTN 625 in addition to an airborne VHF communications
transceiver and airborne VOR/localizer (LOC) and glideslope (G/S) receivers. The GTN 650 meets the
requirements of the TSO specified in Table 1-6.
CAUTION
The GTN has a display that is coated with a special anti-reflective coating that is very
sensitive to waxes and abrasive cleaners. CLEANERS CONTAINING AMMONIA WILL
HARM THE ANTI-REFLECTIVE COATING. It is very important to clean the display
using a clean, lint-free cloth and an eyeglass lens cleaner that is specified as safe for anti-
reflective coatings.
CAUTION
The use of ground-based cellular telephones while aircraft are airborne is prohibited by
FCC rules. Due to potential interference with onboard systems, the use of ground-based
cell phones while the aircraft is on the ground is subject to FAA regulation 14

CFR §91.21. FCC regulation 47 CFR §22.925 prohibits airborne operation of ground-
based cellular telephones installed in or carried aboard aircraft. Ground-based cellular
telephones must not be operated while aircraft are off the ground. When any aircraft
leaves the ground, all ground-based cellular telephones on board that aircraft must be
turned off. Ground-based cell phones that are on, even in a monitoring state, can disrupt
GPS/SBAS performance.