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GTS 8XX/GPA 65 Installation Manual
Revision 4TP
190-00587-00
1.5.2.2 GTS 820
TSO/ETSO Deviation
1. Garmin was granted a deviation from TSO-C147 section 1.c to use RTCA DO-160E, instead of
RTCA DO-160D as the standard for Environmental Conditions and Test Procedures for Airborne
Equipment.
TSO-C147
2. Garmin was granted a deviation from TSO-C147 Appendix 1 section 1.6 to use selective Mode S
interrogations as specified by RTCA DO-185A section 2.2.3.8.1 and 2.2.3.9 following all the
applicable protocols for Mode-S surveillance interrogations in the NAS as stated in DO-185A and
DO-181C.
1. Garmin was granted a deviation from RTCA DO-197A section 2.2.3.2.1 to use the Interrogations
Spectrum requirement of RTCA DO-185A section 2.2.3.3 instead of the requirement of RTCA DO-
197A section 2.2.3.2.1
2. Garmin was granted a deviation from RTCA DO-197A section 2.2.3.5 to use the “Mode C Only
All-Call” format specified by RTCA DO-185A section 2.2.3.8.1 instead of the “Mode C” format for
ATCRBS interrogations.
3. Garmin was granted a deviation from RTCA DO-197A section 2.2.9.1 to realize the bearing
estimation function using a direction finding antenna augmented by tracked correlated ADS-B data
when such data is available and of sufficient integrity.
RTCA DO-197A
4. Garmin was granted a deviation from RTCA DO-197A section 2.2.11 to use the suppression
pulse on the aircraft suppression bus specified by RTCA DO-185A section 2.2.3.12 (70 +/-1 µs from
top antenna and 90 +/-1 µs from bottom antenna) instead of 100 +/-5 µs.
1. Garmin was granted a deviation to use DO-185A as modified by Appendix 1 of TSO-C119B and
‘RWG Recommended Modification 2.0 to TSO-C119B.’
2. Garmin was granted a deviation from RTCA DO-185A section 2.2.3.8.2 Mode S signal definition.
3. Garmin was granted a deviation from RTCA DO-185A section 2.2.4.4.2.2.b to use the Enhanced
Preamble Detection method of RTCA DO-260A Appendix I section I.4.1.
4. Garmin was granted a deviation from RTCA DO-185A section 2.2.4.4.2.2.c to use the Baseline
Multi-sample bit and confidence declaration technique of RTCA DO-260A Appendix I section
I.4.2.3.1.
RTCA DO-185A
5. Garmin was granted a deviation from RTCA DO-185A section 2.4.2.1.1.4.
1. Garmin was granted a deviation from RTCA DO-260A section 2.2.4.3.4.7.3.b to use the
Conservative and Brute Force error correction techniques specified by RTCA DO-260A section
2.2.4.4.3.1 instead of section 2.2.4.4.2.2.d and Appendix A, Section 3 of RTCA DO-185A.
2. Garmin was granted a deviation from RTCA DO-260A section 2.2.4.4.2 to use the Conservative
and Brute Force error correction techniques specified by RTCA DO-260A section 2.2.4.4.3.1
instead of section 2.2.4.4.2.2.d and Appendix A, Section 3 of RTCA DO-185A.
RTCA DO-260A
3. Garmin was granted a deviation from RTCA DO-260A section 2.2.4.5.b to use the Conservative
and Brute Force error correction techniques specified by RTCA DO-260A section 2.2.4.4.3.1
instead of section 2.2.4.4.2.2.d and Appendix A, Section 3 of RTCA DO-185A.
