GTX345r TCAS integration behavior

Any DA40 related topics

Moderators: Rick, Lance Murray

Post Reply
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

GTX345r TCAS integration behavior

Post by smoss »

My recently upgraded transponder with the TAS600 data integrated into it has some odd behavior that perhaps others with this setup could offer some insight. Pre-upgrade, the TCAS would fire up in "ground mode", wit only targets >200 ft above you showing on the G1000, and would then self transition into flight mode after takeoff. While no-one at Garmin or Diamond could provide me with the specific trigger for transition (airspeed, etc.), the TAS600 manual appears to note that once you climb 400 ft from turn-on altitude, it will transition out of ground, but with the caveat that there may be an "on ground" switch also, such as airspeed, that would put it back into ground mode. My problem is this--my new setup starts the TAS600 apparently in "standby mode" (shown in Garmin Pilot traffic map page), and then in the air transitions to "ON" (per Garmin Pilot TCAS indication on traffic map page), BUT this means I see no TCAS air targets at all on the ground (while the ADS-B ones do show up), and then to boot, once it switches to "ON", I am apparently only seeing TCAS targets above me, never ever same altitude or below, making me believe it is "ON", but in ground mode. My avionics shop is stumped, Garmin had no wisdom, haven't spoken with Avidyne yet.
For others with this setup,
1- does Garmin pilot show TCAS as "on" or "standby" on the ground, and do you see TCAS targets in the sky while on the ground? Seems like might have been poor programming by Garmin.
2 - any issues seeing TCAS targets same altitude or below?

I have had the system for 2 months now, but it is extremely difficult to test or note the airborne problem, because 99% of my flying is in areas with ADS-B towers and TIS-B rebroadcast, which seems to be favored by the GTX over the TCAS, and most have ADS-B anyways. The only way to see it is in radar free holes, I have only one small one near me. I finally got a buddy to fly his Mode-C only plane to the radar hole with me in my plane, and as soon as we neared it, he dropped of the TIS-B and was no longer seen by my system at the same altitude and lower, less than a mile away from me. Or perhaps it is just coincidence, and his transponder took a momentary dump at that spot, and I am paranoid :scratch:
Steve
DA40 XL
Post Reply