Garmin GTS 855 - Manual (Page 14)

10 Garmin GTS 8XX Series Traffic Advisory System 190-00587-02 Rev. A
Intruder Altitude
and Vertical Trend
Figure 5 Intruder Altitude and Vertical Trend Arrow
The GTS 8XX Series automatically suppresses the display of altitude-reporting
aircraft on the ground under either of the following conditions:
• On-ground aircraft is equipped with a Mode S transponder that reports the
on-ground state.
• On-ground aircraft is equipped with a Mode C transponder, and own
aircraft’s radar altimeter (if installed) is displaying 1700 feet AGL or less.