Garmin GTS 8 Series User manual

190-01279-01 July 2018 Revision 2
GTS 8XX
Part 23 AML STC Maintenance Manual
with Instructions for Continued Airworthiness
Aircraft Make, Model, Registration Number, and Serial
Number, and accompanying STC configuration
information in Appendix A, must be completed and saved
with aircraft permanent records.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page i
© 2014-2018 Garmin International or its subsidiaries
All Rights Reserved
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 prior
written consent of Garmin. Garmin hereby grants permission to download a single copy of this manual and
of any revision to this manual onto a hard drive or other electronic storage medium to be viewed and to
print one copy of this manual or of any revision hereto, provided that such electronic or printed copy of this
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.
Garmin®, flyGarmin®, and flyGarmin.com®are registered trademarks of Garmin International or its
subsidiaries. GDU™, GDL™, GNS™, GTN™, GTS™, and GTX™ are trademarks of Garmin
International or its subsidiaries. These trademarks may not be used without the express permission of
Garmin.
Adobe®is a registered trademark of Adobe Systems Incorporated. All rights reserved.
All other product or company names mentioned in this manual are trade names, trademarks, or registered
trademarks of their respective owners.
For aviation product support, visit flyGarmin.com.
For information regarding the Aviation Limited Warranty, refer to Garmin’s website.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page ii
RECORD OF REVISIONS
CURRENT REVISION DESCRIPTION
Revision Revision Date Description
1 05/01/2014 Initial Release.
207/25/2018 Added information pertaining to the GTS 800, 820, and 850.
Section Description of Change
1.3.1
Updated “GTS Processor” to “GTS 800/820/850/825/855.”
Updated “GTS Processor LRU” to “GTS 825 or 855 LRU.”
Added “GTS 8X0 refers to the GTS 800, 820, or 850 LRU at the core of the GTS 8XX
system.”
1.4 Added GTS 8X0/GPA 65 (GTS 800/GTS 820/GTS 850) Installation (P/N 190-00587-00).
2.3 Added GTS 800 and GTS 820/850 requirements to Table 2-1 GTX 8XX System Current
Requirements.
4.3
Updated procedure for antenna visual inspection to define inspection criteria.
Updated procedure for antenna visual inspection - suspected lightning strike to include
inspection criteria.
5.1 Added “GTS 8X0 Install Tool (P/N 006-A0242-00).”
5.3 Updated “Baro Altitude” fault to “Pressure Altitude” in Table 5-1 GTS 8XX System Faults.
6.1 Added Section 6.1 GTS 8X0.
6.2 Added Section 6.2 GPA 65.
7.3 Added content for GTS 8X0 Install Tool (P/N 006-A0242-00).
7.3.1 Added note regarding GTS 8XX install tools.
Appendix A Updated title of Appendix A to “Aircraft Installation Record.”
A.2.1 Added GDU 7XX equipment reference to Table A-1 GTS 8XX System Interfaces to
Garmin Equipment.
A.3 Updated aircraft profile to Figure A-2 Equipment Location and Wire Routing - Twin
Engine Airplane.
Appendix B Updated title of Appendix B to “Electrical Bonding Procedures.”
B.3
Added flag notes for Figure B-7.
Added 5:1length-to-width ratio requirement.
Added bonding strap restriction of six inches.
B.4 Added bonding strap restriction of six inches.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page iii
INFORMATION SUBJECT TO EXPORT CONTROL LAWS
This document may contain information that is subject to the Export Administration Regulations (EAR)
issued by the United States Department of Commerce (15 CFR, Chapter VII, Subchapter C) and may not
be exported, released, or disclosed to foreign nationals inside or outside of the United States without first
obtaining an export license.
Information in this document is subject to change without notice. For updates and supplemental
information regarding the operation of Garmin products, visit flyGarmin.com.
DEFINITIONS OF WARNINGS, CAUTIONS, AND NOTES
WARNING
A Warning means injury or death is possible.
CAUTION
A Caution means that damage to the equipment is possible.
NOTE
A Note provides additional information.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page iv
TABLE OF CONTENTS
1 INTRODUCTION..............................................................................................................................1-1
1.1 Scope ..........................................................................................................................................1-2
1.2 Organization ...............................................................................................................................1-2
1.3 Definitions and Abbreviations ...................................................................................................1-3
1.4 Related Publications...................................................................................................................1-3
1.5 Distribution.................................................................................................................................1-4
2 GENERAL DESCRIPTION.............................................................................................................2-1
2.1 System Overview .......................................................................................................................2-2
2.2 Equipment Description...............................................................................................................2-2
2.3 Electrical Current Requirements ................................................................................................2-2
2.4 Interface Summary .....................................................................................................................2-3
2.5 Ground Plane..............................................................................................................................2-4
3 CONTROL AND OPERATION.......................................................................................................3-1
4 INSTRUCTIONS FOR CONTINUED AIRWORTHINESS.........................................................4-1
4.1 Airworthiness Limitations..........................................................................................................4-2
4.2 Servicing Information ................................................................................................................4-2
4.3 Maintenance Intervals ................................................................................................................4-3
5 TROUBLESHOOTING ....................................................................................................................5-1
5.1 Troubleshooting Software ..........................................................................................................5-2
5.2 Assert Log Diagnosis .................................................................................................................5-3
5.3 System Faults .............................................................................................................................5-4
6 EQUIPMENT REMOVAL AND RE-INSTALLATION...............................................................6-1
6.1 GTS 8X0 ....................................................................................................................................6-2
6.2 GPA 65.......................................................................................................................................6-2
6.3 GTS Processor............................................................................................................................6-3
6.4 Configuration Module ................................................................................................................6-3
6.5 Antenna Coaxial Cable...............................................................................................................6-4
6.6 Directional Antenna ...................................................................................................................6-6
6.7 Omni-directional (Monopole) Antenna......................................................................................6-7
7 RETURN TO SERVICE...................................................................................................................7-1
7.1 Maintenance Records .................................................................................................................7-2
7.2 Return to Service Requirements.................................................................................................7-2
7.3 Configuration and Checkout ......................................................................................................7-3
7.4 System Checkout........................................................................................................................7-8
APPENDIX A AIRCRAFT INSTALLATION RECORD...................................................................A-1
A.1 General Installation Information ...............................................................................................A-2
A.2 Interfaced Equipment ................................................................................................................A-3
A.3 Equipment Locations and Wire Routing...................................................................................A-5
A.4 Configuration Log .....................................................................................................................A-8
A.5 Aircraft Wiring Diagrams .........................................................................................................A-9
APPENDIX B ELECTRICAL BONDING PROCEDURES...............................................................B-1
B.1 Considerations for Untreated or Bare Dissimilar Metals .......................................................... B-2
B.2 Preparation of Aluminum Surfaces ........................................................................................... B-3
B.3 Composite Aircraft.................................................................................................................... B-4
B.4 Tube and Fabric Aircraft ........................................................................................................... B-9

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page v
LIST OF FIGURES
Figure 2-1 GTS 8XX System Interface Diagram ..................................................................................2-3
Figure 3-1 GTS 8XX Traffic System Controls ......................................................................................3-1
Figure 5-1 GTS Assert Log Diagnosis Tool ..........................................................................................5-3
Figure 7-1 GTS Processor Install Tool - Normal Tab ...........................................................................7-4
Figure 7-2 GTS Processor Install Tool - Configuration Tab .................................................................7-6
Figure 7-3 GTS Processor Install Tool - Upload Tab ............................................................................7-7
Figure 7-4 GTS Processor Install Tool - Assert Tab .............................................................................7-7
Figure 7-5 GTS Processor Install Tool - Normal Tab ...........................................................................7-9
Figure 7-6 Target Aircraft Position for Traffic Display Flight Check ................................................7-11
Figure A-1 Equipment Location and Wire Routing - Single-Engine Airplane ....................................A-6
Figure A-2 Equipment Location and Wire Routing - Twin Engine Airplane ......................................A-7
Figure A-3 GTS 8XX System Configuration Log ................................................................................A-8
Figure B-1 Electrical Bonding Preparation – Nut Plate ....................................................................... B-2
Figure B-2 Electrical Bonding Preparation – Bolt/Nut Joint ................................................................ B-2
Figure B-3 Electrical Bond Preparation – Terminal Lug ..................................................................... B-2
Figure B-4 Fiberglass Insulation for Carbon Material ......................................................................... B-4
Figure B-5 Aluminum Tape Joint ......................................................................................................... B-6
Figure B-6 Aluminum Tape Ground Termination ................................................................................B-6
Figure B-7 GTS Processor Aluminum Tape Installation ..................................................................... B-7
Figure B-8 Electrical Bonding Using Conductive Clamp .................................................................. B-11

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page vi
LIST OF TABLES
Table 2-1 GTS 8XX System Current Requirements .............................................................................2-2
Table 2-2 Ground Plane Definitions and Ground Path Resistance Requirements ................................2-4
Table 5-1 GTS 8XX System Faults .......................................................................................................5-4
Table 6-1 Recommended Coaxial Cable Length ...................................................................................6-5
Table 7-1 GTS 8XX System Flag Status ...............................................................................................7-5
Table 7-2 Data Source Status Icons .......................................................................................................7-6
Table 7-3 Ramp Test Intruder Scenario ...............................................................................................7-10
Table A-1 GTS 8XX System Interfaces to Garmin Equipment ............................................................A-3
Table A-2 GTS 8XX System Interfaces to Other Equipment ...............................................................A-4
Table A-3 GTS 8XX Equipment Locations ..........................................................................................A-5
Table B-1 Composite Airframe Bonding Strap Assembly .................................................................... B-5
Table B-2 Bonding Strap Assembly for Air-craft with Tubular Airframes ........................................ B-10

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 1-1
1 INTRODUCTION
1.1 Scope................................................................................................................................... 1-2
1.2 Organization........................................................................................................................ 1-2
1.3 Definitions and Abbreviations ............................................................................................ 1-3
1.3.1 Definitions.................................................................................................................................1-3
1.3.2 Abbreviations .............................................................................................................................1-3
1.4 Related Publications ........................................................................................................... 1-3
1.5 Distribution ......................................................................................................................... 1-4

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 1-2
1.1 Scope
This document provides maintenance instructions and Instructions for Continued Airworthiness (ICA) for
the GTS 8XX Traffic System as installed under STC SA02121SE. This document satisfies the requirements
for continued airworthiness as defined by 14 CFR Part 23.1529 and 14 CFR Part 23 Appendix G.
1.2 Organization
The following outline briefly describes the organization of this manual:
Section 2: System Description
This section provides a description of the equipment installed by this STC. An overview of the GTS 8XX
system interface is also provided.
Section 3: Control and Operation
This section provides basic control and operation information in relation to maintenance practices. Basic
GTS configuration and software loading is also described.
Section 4: Instructions for Continued Airworthiness
This section provides instructions to maintain continued airworthiness of the GTS 8XX system and system
airworthiness limitations.
Section 5: Troubleshooting
This section provides troubleshooting information to diagnose and resolve problems with GTS 8XX
system equipment.
Section 6: Equipment Removal and Reinstallation
This section provides instructions for the removal and re-installation of GTS 8XX system equipment.
Section 7: Return to Service
This section specifies return to service procedures to be performed upon completion of maintenance of
GTS 8XX system equipment.
Appendix A: Aircraft Installation Record
This appendix is used to record information for a specific GTS 8XX system installation.
Appendix B: Electrical Bonding Procedures
This appendix provides special bonding procedures for non-metallic aircraft.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 1-3
1.3 Definitions and Abbreviations
1.3.1 Definitions
“GTS 8XX system” refers to the complete system, including GTS 800/820/850/825/855, antennas, and
associated equipment.
“GTS Processor” refers to the GTS 825 or 855 LRU at the core of the GTS 8XX system.
“GTS 8X0” refers to the GTS 800, 820, or 850 LRU at the core of the GTS 8XX system.
1.3.2 Abbreviations
The following terminology is used within this document:
AML Approved Model List
ADS-B Automatic Dependent Surveillance-Broadcast
CFR Code of Federal Regulations
DME Distance Measuring Equipment
FAA Federal Aviation Administration
HSDB High Speed Data Bus
ICA Instructions for Continued Airworthiness
LRU Line Replaceable Unit
MFD Multi-Function Display
SL Sensitivity Level
STC Supplemental Type Certificate
TA Traffic Advisory
TAS Traffic Advisory System
TCAS Traffic Alert and Collision Avoidance System
TSO Technical Standard Order
In this manual, references to GTS 8XX Part 23 AML STC Installation Manual
(P/N 190-01279-00) may be
abbreviated as the “STC IM.”
1.4 Related Publications
Part Number Document
005-00738-01 Master Drawing List, GTS 8XX Part 23 AML STC
005-00738-02 Equipment List, GTS 8XX Part 23 AML STC
190-00587-00 GTS 8X0/GPA 65 (GTS 800/GTS 820/GTS 850) Installation Manual
190-00587-02 GTS Traffic Systems Pilot’s Guide
190-00587-50 GTS Processor (GTS 825/855/8000) Installation Manual
190-00587-51 GTS Processor Maintenance Manual
190-01279-00 GTS 8XX Part 23 AML STC Installation Manual
700704 L-Band/DME Blade Antenna P/N L10-611-( ) Limitations and Installation Instructions
700784 Dayton-GrangerInc. General Installation Instructions for Antennas

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 1-4
1.5 Distribution
This document contains instructions required to maintain continued airworthiness of the GTS 8XX system.
When this
document is revised, every page will be revised to indicate the current revision level. Garmin
dealers may
obtain the latest revision of this document on the Garmin Dealer Resource Center website.
Owner/operators may obtain the latest revision of this document from flyGarmin.com.
A Garmin Service Bulletin describing the revision to this document will be sent to Garmin dealers if the
revision is determined to be significant.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 2-1
2 GENERAL DESCRIPTION
2.1 System Overview................................................................................................................ 2-2
2.2 Equipment Description .......................................................................................................2-2
2.3 Electrical Current Requirements......................................................................................... 2-2
2.4 Interface Summary.............................................................................................................. 2-3
2.5 Ground Plane ...................................................................................................................... 2-4

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 2-2
2.1 System Overview
The GTS 8XX system is designed to use active interrogations of Mode S and Mode C transponders to
provide Traffic Advisories (TA) to the pilot. Traffic is displayed on a multifunction display (MFD) via
ARINC 429 and/or High Speed Data Bus (HSDB). An overview of the GTS 8XX system and its interfaces
are shown in Figure 2-1.
2.2 Equipment Description
The GTS 8XX is a microprocessor-based Line Replaceable Unit (LRU) that uses active interrogations of
Mode S and Mode C transponders to provide Traffic Advisories (TAs) to the pilot.
When properly configured, the GTS 8XX system will utilize passive surveillance to provide ADS-B In
traffic. The GTS ADS-B In capability allows the unit to receive traffic data through its 1090 MHz
Extended Squitter (1090 ES) receiver. Using the received ADS-B Out broadcasts, the system provides
correlated information about target aircraft, including identification, speed, and direction. GPS and
magnetic heading inputs to the GTS 8XX are required for ADS-B In to operate. Although ADS-B In relies
on 1090ES ADS-B Out broadcasts from other aircraft, it is not necessary for the GTS-equipped aircraft to
broadcast an ADS-B Out signal.
Aural alerts are provided to inform the crew of TAs. A top-mounted directional antenna is used to derive
bearing of the intruder aircraft, which is displayed with relative altitude to own aircraft. Top antenna
transmitted interrogations are directional, reducing the number of transponders that receive the
interrogation, thus reducing potential garble on the 1090 MHz band. An optional bottom antenna transmits
omni directional interrogations. A bottom directional antenna installation gives the benefit of intruder
bearing visibility for targets that are shaded from the top directional antenna. Target bearing accuracy may
be degraded on fixed gear aircraft with a bottom directional antenna.
2.3 Electrical Current Requirements
Table 2-1 shows current requirements for the GTS 8XX system.
Table 2-1 GTS 8XX System Current Requirements
LRU 14V Current Draw 28V Current Draw
Typical Maximum Typical Maximum
GTS 800 2.2 A 2.6 A 1.1 A 1.5 A
GTS 820/850 2.7 A 3.2 A 1.3 A 1.6 A
GTS Processor 3.5 A 7.5 A 1.7 A 3.1 A

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 2-3
2.4 Interface Summary
The GTS 8XX system is designed as an open architecture system that uses ARINC 429, RS-232, and
HSDB communications interfaces, as well as analog and discrete inputs and outputs. GTS 8XX interfaces
include:
Figure 2-1 GTS 8XX System Interface Diagram
• Three RS-232 Inputs/Outputs • Alert Audio Output
• Two RS-422 Input/Output • Ten Active Low Discrete Inputs
• Twelve ARINC 429 Inputs/Outputs • Two Active High Discrete Inputs
• Configuration Module • External Suppression Input/Output
• Aircraft Power Input • Four Annunciator Outputs
• Analog Radar Altimeter Input • HSDB Input/Output
• 26 VAC Heading Reference Input
Mode S Transponder
Compatible TX/RX interface
required for power programming
GTS TRAFFIC SYSTEM
Top
Directional
Antenna
Mode C Replies
Mode S Replies
Mode S Squitters
Mode C Interrogations
Broadcast Messages
Mode S Interrogations
1090MHzRX
1090MHzR
X
1030MHzTX
Optional
Top
Antenna
Bottom
Antenna
Mode A/C/S
Replies
Mode S Squitter
Mode A/C
Interrogations
Mode S Interrogations
Broadcast Messages
1090MHzTX
1090MHzTX
1030MHzRX
1030MHzR
X
Suppression Bus
Audio Inhibit
Audio Output
Pressure Altitude*
OR
OR
OR
Transponder
Serializer
Magnetic Heading*
(optional)
Radar Altimeter
(optional)
GPS PVT*
(optional)
Data Source
Options
HSDB
Analog I/O
Discrete I/O
RS-232
ARINC 429
LRU Data
OPR/SBY
Self Test
Control/Display*
Unit
Color Display
Knobs/Buttons
Mode S Transponder
(Optional Second Unit)
Compatible TX/RX interface
required for power programming
Optional
Top
Antenna
Bottom
Antenna
Mode A/C/S
Replies
Mode S Squitter
Mode A/C
Interrogations
Mode S Interrogations
Broadcast Messages
1090MHzTX
1090MHzTX
1030MHzR
X
1030MHzRX
Display Unit*
Color Display
Pressure Altitude
Magnetic Heading
GPS PVT
Radio Altitude
Air /Gnd Status
Ldg Gear Position
Mode S TX/RX interface
Control/Display
Ldg Gear Position
Air/Gnd Status
OR
Optional
Bottom
Directional or
Monopole
Antenna
GTS 800 TAS
GTS 820 TAS
GTS 825 TAS
GTS 850 TCAS I
GTS 855 TCAS I
Self Test /
Alt Filter
OPR/SBY External control inputs required
if Display Unit is only unit installed
Audio Panel
High-Priority
Audio Source
(e.g.,TAWS)
(Optional)
(Req’d for retractable ldg gear)
*The HSDB interface can perform all
of the listed interface functions in
place of separate analog/digital
interfaces.
TRFC Mute
(Optional)
1030MHzTX
G950/G1000 System*
OR

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 2-4
2.5 Ground Plane
Ground plane definition varies with airframe type and aircraft model, as defined in Table 2-2. Refer to the
periodic test and reconditioned resistance values corresponding to these ground plane definitions when
performing the equipment bonding test per Section 4.3. Ensure that all GTS 8XX system antenna coaxial
cables are disconnected during resistance checks.
Table 2-2 Ground Plane Definitions and Ground Path Resistance Requirements
Notes:
[1] Diamond DA 40 and DA 40F with Diamond OSB 40-004/3 incorporated, or aircraft with
similar factory-installed lightning protection supporting IFR operation.
Aircraft Type/Model Ground
Reference
Maximum Resistance Between
GTS 8XX
Chassis and Ground
Reference (mΩ)
Notes
Periodic Test Reconditioned
Metal airframe Nearby metallic
structure 10.0 2.5
Tube airframe with fabric cover Nearby metallic
structure 10.0 2.5
Composite VFR-only Models
Diamond DA 40,
DA 40F Instrument panel 50.0 25.0
Composite IFR Models
Cessna
LC40-550FG,
LC41-550FG,
LC42-550FG
Nearby aluminum
lightning
ground
bar/strip
10.0 5.0
Cirrus
SR20,
SR22,
SR22T
Local grounded
structure
(such as
seat support
structure, entry
step)
10.0 5.0
Diamond
DA 40,
DA 40F
Nearby structure
lightning
ground
tube
10.0 5.0 [1]
DA 42,
DA 42 N-MG
Nearby lightning
ground 10.0 5.0

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 3-1
3 CONTROL AND OPERATION
The GTS 8XX system includes functions that can be controlled via configured displays or external
switches. Figure 3-1 summarizes GTS 8XX system control. Refer to display documentation for traffic
system control details.
Operate/Standby
The Operate/Standby function toggles the GTS 8XX system between Operate and Standby modes.
Operate/Standby may be controlled through a compatible display or external switch.
Self-Test
The GTS 8XX built-in self-test function may be controlled either through a compatible display or an
external switch.
Traffic Mute (optional)
The optional Traffic Mute function mutes traffic audio alerts and is controlled by an external switch.
Figure 3-1 GTS 8XX Traffic System Controls
Traffic Mute

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 4-1
4 INSTRUCTIONS FOR CONTINUED AIRWORTHINESS
4.1 Airworthiness Limitations .................................................................................................. 4-2
4.2 Servicing Information ......................................................................................................... 4-2
4.2.1 Periodic Maintenance.................................................................................................................4-2
4.2.2 Special Tools ..............................................................................................................................4-2
4.3 Maintenance Intervals......................................................................................................... 4-3
This document is designed for use by the installing agency of the Garmin GTS 8XX Traffic System as
Instructions for Continued Airworthiness in response to 14 CFR 23.1529 and 14 CFR 23 Appendix G. This
ICA includes information required by the operator to adequately maintain the GTS 8XX system installed
under the Approved Model List (AML) STC.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 4-3
4.3 Maintenance Intervals
Maintenance Item Interval Description/Procedure
Antenna visual inspection 12 calendar months
Visually inspect the GTS 8XX system antenna(s) for the following:
• Environmental seal damage or decomposition
• Cracks in the antenna body
• Mounting structure damage or deformation
• Corrosion on metallic structures
If the antenna is not properly attached, or the antenna seal shows signs of damage or deterioration,
complete
the following procedure:
1. Remove, clean, and reattach the antenna.
2. Complete the antenna electrical bonding test as described below.
3. Reseal the antenna.
If the antenna is damaged or cracked, remove and replace the antenna in accordance with Section 6
(antenna(s) installed under this STC), or the antenna installation data (antenna(s) not installed under this
STC). After installing antenna, complete the antenna electrical bonding test described below (if applicable).
If aircraft structure, at location of the antenna, is deformed or damaged, remove the antenna and repair
aircraft structure in accordance with aircraft model-specific structural repair manual. After the aircraft repair
is complete, perform the following:
1. Clean and reattach the antenna.
2. Complete the antenna electrical bonding test as described below (if applicable).
3. Reseal the antenna.
Antenna visual inspection -
suspected lightning strike
Suspected or actual
lightning strike
In the event of a suspected or actual lightning strike to the aircraft, the GTS 8XX system antenna(s) and
antenna cable installation must be inspected.
1. Inspect the antenna(s) and surrounding area for structural damage.
a. If the antenna is damaged, replace the antenna in accordance with Section 6.
b. If the aircraft structure supporting the antenna installation is deformed or damaged,
remove the antenna and repair in accordance with procedures detailed in the aircraft
model-specific structural repair manual. When repair is complete, continue with the
following steps.
2. Inspect the antenna and coaxial cable connector ends for damage. If any damage is found on any
antenna or coaxial cable connector, replace the antenna(s) or coaxial cable(s) in accordance with
Section 6.
3. Ensure that the coaxial cable connectors are securely attached to the antenna connectors.
4. Perform the GTS 8XX system checkout procedure in accordance with Section 5.

190-01279-01 GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2 Page 4-4
Maintenance Item Interval Description/Procedure
Antenna electrical bonding test
(Not applicable to
composite
VFR-only
models)
Every 2000 flight
hours
or ten years,
whichever
is first
An electrical bonding test must be performed on all GTS 8XX system antennas. The test procedure is:
1. Gain access to the antenna.
2. Disconnect the coaxial cable connector(s) from the antenna.
3. Measure the resistance between the antenna coaxial connector body and a nearby exposed portion
of aircraft metallic structure (e.g., exposed rivet on fuselage stringer).
4. Verify the resistance is less than or equal to 10 mΩ.
5. Reconnect the antenna connector(s).
In the event of bonding test failure, perform the following procedure:
1. Remove the antenna, clean, and re-install in accordance with Section 6.
2. Measure the resistance between the antenna coaxial connector body and a nearby exposed portion
of aircraft structure (e.g., exposed rivet on fuselage stringer).
3. Verify the resistance is less than or equal to 2.5 mΩ.
Equipment electrical bonding
test
Following removal
and
replacement of
the
GTS 8XX install
rack or bonding
components
AND
Every 2000 flight
hours
or ten years,
whichever
is first
1. Disconnect the coaxial cable connector(s) from the GTS 8XX.
2. Disconnect P8001, P8002, and P8003 connectors from the GTS 8XX.
3. Measure the DC resistance between the GTS 8XX chassis and the aircraft ground, as defined in
Table 2-2. Verify the resistance is less than or equal to the appropriate periodic test resistance value
listed in Table 2-2.
In the event of bonding test failure, perform the following procedure:
1. Remove GTS 8XX and install rack from the aircraft per instructions in Section 6.
2. Ensure that the GTS 8XX and install rack are clean and free of dirt and debris.
3. Ensure that all ground path components are in good condition and properly connected and attached
to the aircraft.
4. Re-install the GTS 8XX and install rack in accordance with Section 6.
5. Measure the resistance between the GTS 8XX chassis and the aircraft ground,
as defined in Table 2-2.
6. Verify the resistance is less than or equal to the appropriate reconditioned resistance value listed in
Table 2-2.
Equipment removal and
replacement On condition Remove and replace the GTS 8XX and/or GTS 8XX system antenna.
See Section 6 for equipment removal and re-installation instructions.