Garmin Pilot Full TIS-B Traffic and Ownship Detection

[AaronDC8402]

We recently had a GTX 330ES installed in our Mooney to meet the upcoming ADS-B Out requirement. We also have a GDL39 for ADS-B In info. I expected now that we're ADS-B compliant that I would start receiving more info from the ground stations. That has not happened, and I'm wondering if anyone has any suggestions or experience on the topic.

To recap, we have

• GTX 330ES (configured to report Dual in capability)
• GDL 39 3D
• Garmin Pilot (running on Samsung Tab S)
• GNS 480

The top left corner of the map page shows 2 icons related to incoming info on the GDL. Air to Air shows correctly. The antenna icon shows a red X. In the ADSB settings page, it reports "Full TIS-B Traffic" as "No". On "Ownship detected" there is also a "No". Garmin tech support has been somewhat helpful by pointing out that the ES needs to report the UAT In capability to the stations. That is now set correctly (I think), but still no TIS-B or ownship. They have offered no suggestions to confirm that I have Pilot and the GDL set up correctly. They are mostly pointing fingers at the ES, and suggesting I ask a Garmin dealer about the issue.

I did have Full TIS-B and ownship detected about a year ago when I was regularly flying a ADS-B compliant 182.

 

[AaronDC8402]

Oh, and since you guys/gals seem to like seeing various tablet mount solutions, I'll share mine. It's slightly relevant, although it is an old picture. This is prior to the ES, G5, EDM830 install.

 

Edited January 26, 2017 by AaronDC8402

[ArtVandelay]

Where are you doing your flight testing? If there is no UAT traffic or it doesn't know you have in capability, there will be no UAT in. Might be worth a try in a busy airspace where there is other UAT traffic. There is also some parts of USA that don't have ground stations.

[AaronDC8402]

I could have mentioned a little about that. I fly in/out of a class C airport (KTYS). Not the busiest "C" airport, but there should be some TIS-B traffic showing up. At cruise the other day, I was showing 3 active stations at one time.

Your question about the stations not knowing that I'm UAT in capable. I think I've addressed that, but not 100% sure. Below is part of the report that shows In capability as DUAL. The question is, does that fully confirm everything is set up right on the transponder? Or could there be something else configured wrong on the ES?

 

[ArtVandelay]

When you go to Connext page, what do you see under ADSB tab? I have GDL88 and FS210, so I don't have any experience with 39. If you have a laptop you could order a SDR usb device, and check what you xmit/recv: search for rtl1090.

[jackn]

It may be a bug in the GP app. I have a gtx345, gtn750, & GP. I also have the red X through the tower icon on GP, although it's fine on the 750. Both displays are getting traffic info from the same source (gtx345). I know I'm seeing tis-b on GP and traffic targets match for both devices. Garmin support seemed confused, so pushed me back to the installer. I haven't had the time yet to deal with this, and Garmin put out a new software update that I haven't yet tried. 

[AaronDC8402]

Jack, are you on Apple or Android?

 

[jackn]

iOS 

[Marauder]

Timely conversation since I will be updating my plane with ADS-B shortly and in a similar manner. The GTX-330 ES and what I am installing (L-3 9000+) should act the same -- in other words, there is not direct information being fed to Garmin Pilot from either device. Like you, I will be relying upon a GDL-39 to trigger traffic and weather on my Garmin Pilot app. Like you, I assumed that with an ADS-B out device in the plane, I would be getting full TIS-B on Garmin Pilot.

Just so everyone is talking in the same terms. Here is what the GP manual shows for the different states of traffic can be:

Based on what I think I am seeing in your picture, you look like you are in ADS-B (air to air) mode and not receiving TIS-B. I would check the GP Connext page for the GDL-39's connection status. You may be having a problem with the GDL-39.

I will be curious how this plays out since I am headed in the same direction.

[AaronDC8402]

GDL 39's connection status shows connected, and I'm showing connected to multiple ground stations. The more I'm reading up on it, the more I'm thinking something isn't triggering the ground stations to send the TIS-B info. Per Garmin's request, I called my installer (Gann Aviation) this morning. We hired them to install a 330ES. We did NOT hire them to install a GDL39, so understandably they are a little at a loss for help. The 330ES seems to function, Garmin Pilot is where the problem shows up. Ron at Gann is going to call his Garmin rep to query him on the situation. Since this is a certified aircraft, Garmin tech support refuses to discuss the 330ES configuration settings with me.

[Marauder]

4 minutes ago, AaronDC8402 said:

GDL 39's connection status shows connected, and I'm showing connected to multiple ground stations. The more I'm reading up on it, the more I'm thinking something isn't triggering the ground stations to send the TIS-B info. Per Garmin's request, I called my installer (Gann Aviation) this morning. We hired them to install a 330ES. We did NOT hire them to install a GDL39, so understandably they are a little at a loss for help. The 330ES seems to function, Garmin Pilot is where the problem shows up. Ron at Gann is going to call his Garmin rep to query him on the situation. Since this is a certified aircraft, Garmin tech support refuses to discuss the 330ES configuration settings with me.

Thanks for the update. If the 330 passed the ADS-B flight test, I would have thought that was all that was needed to trigger the ground stations. 

[ArtVandelay]

Thanks for the update. If the 330 passed the ADS-B flight test, I would have thought that was all that was needed to trigger the ground stations. 

I think the ground stations trigger if they see 978 ADSB transmissions, the 330 can just be using 1090. I think there is a field in the 1090 to tell the ground stations it can receive 978, which OP said was configured to be on. Either this is not the case or the ground stations in his area are ignoring the 1090 bits.

[Bob - S50]

I think it doesn't matter if you are 978 or 1090 OUT.  I think what matters is whether you tell the system you are IN equipped.  If the system (ATC) thinks you have no IN capability it won't bother sending you any info, so you have to make sure your OUT equipment tells ATC that you are IN equipped.  That can be just 978 IN, just 1090 IN, or both IN.

Again, my understanding.  If your OUT equipment tells the system that you are 978 and 1090 IN equipped, it will only send TIS-B traffic (mode C/S) but will not bother sending any information on other aircraft that are ADS-B equipped.  In other words, no ADS-R info.  If your OUT equipment tells ATC you are 978 IN only, it will send you TIS-B and ADS-R on 1090 equipped aircraft, but not on other 978 aircraft.  Similarly, if ATC sees you are 1090 IN only, it will send TIS-B and ADS-R for other 978 equipped planes.

If the system doesn't know you have IN capability you will only see ADS-B equipped aircraft and TIS-B/ASD-R traffic that is being sent out because it is within the hockey puck of somebody who is reporting IN capability.

I also believe that FIS-B doesn't care.  That info is just sent periodically and has nothing to do with your OUT capability.

[PaulM]

The report says that he is IN "DUAL"  which is the proper configuration for a GDL39.  so the ground should be feeding the TIS-B traffic in his hockeypuck.   It says Link version 2.   No matter what, if the ground station receives an ADSB-out signal in the air the ground stations should send the TIS-B data out for that 15NM puck.  (I suppose if you said adsb-in *None* then it wouldn't).. 

I think there is a more verbose copy of that report that you can query (Please send it) .   I would suspect that if the air/ground determination is off that could affect it. 

 

"The antenna icon shows a red X."  That implies that you are not receiving any TIS-B traffic... from anyone.   you should see TIS-B traffic around any ADSB-out target that is in contact with the ground station (not just you) .   a GDL39 doesn't just see your TIS-B traffic... it sees any TIS-B traffic being sent from that tower.... but the tower only broadcasts hockey puck's that it knows of. 

are you getting FIS-B weather?

[Marauder]

1 hour ago, Bob - S50 said:

I think it doesn't matter if you are 978 or 1090 OUT.  I think what matters is whether you tell the system you are IN equipped.  If the system (ATC) thinks you have no IN capability it won't bother sending you any info, so you have to make sure your OUT equipment tells ATC that you are IN equipped.  That can be just 978 IN, just 1090 IN, or both IN.

Again, my understanding.  If your OUT equipment tells the system that you are 978 and 1090 IN equipped, it will only send TIS-B traffic (mode C/S) but will not bother sending any information on other aircraft that are ADS-B equipped.  In other words, no ADS-R info.  If your OUT equipment tells ATC you are 978 IN only, it will send you TIS-B and ADS-R on 1090 equipped aircraft, but not on other 978 aircraft.  Similarly, if ATC sees you are 1090 IN only, it will send TIS-B and ADS-R for other 978 equipped planes.

If the system doesn't know you have IN capability you will only see ADS-B equipped aircraft and TIS-B/ASD-R traffic that is being sent out because it is within the hockey puck of somebody who is reporting IN capability.

I also believe that FIS-B doesn't care.  That info is just sent periodically and has nothing to do with your OUT capability.

There are enough 330ES guys floating around on this site that perhaps one can confirm your theory. It makes sense, what I don't know is what the "out" sends to trigger the "in" response. Could be the 330ES "out" is as TJ suggests and is not sending an "I'm capable of seeing an "in" signal".

[AaronDC8402]

1 hour ago, PaulM said:

The report says that he is IN "DUAL"  which is the proper configuration for a GDL39.  so the ground should be feeding the TIS-B traffic in his hockeypuck.   It says Link version 2.   No matter what, if the ground station receives an ADSB-out signal in the air the ground stations should send the TIS-B data out for that 15NM puck.  (I suppose if you said adsb-in *None* then it wouldn't).. 

I think there is a more verbose copy of that report that you can query (Please send it) .   I would suspect that if the air/ground determination is off that could affect it. 

 

"The antenna icon shows a red X."  That implies that you are not receiving any TIS-B traffic... from anyone.   you should see TIS-B traffic around any ADSB-out target that is in contact with the ground station (not just you) .   a GDL39 doesn't just see your TIS-B traffic... it sees any TIS-B traffic being sent from that tower.... but the tower only broadcasts hockey puck's that it knows of. 

are you getting FIS-B weather?

The full report is attached to this message. Let me know if you see anything meaningful. It is mostly over my head. The first test I ran showed "1090" as In capability. After changing the configuration of the 330ES, I ran the report and got what is attached showing DUAL in.

I am getting FIS-B weather. I see some aircraft, but it doesn't seem to be the full TIS-B picture. It seems to be functioning exactly as it did before we got the ADSB install. 

The 182 that I used to fly frequently is ADSB-out compliant as well. When I would fly it, I would get the antenna icon illuminated and see TIS-B traffic. I have also wondered if the GDL or Pilot have somehow latched onto that plane, and it's looking only for that plane as ownship. I feel like I'm grasping at straws with that thought.

 

Thanks everyone for all the help so far!

 

PAPR_20170123_A0323F_33477743.pdf

[thinwing]

Re the Garmin gdl39...I installed an external antenna on the belly that really improved reception

[Marauder]

1 hour ago, AaronDC8402 said:

The full report is attached to this message. Let me know if you see anything meaningful. It is mostly over my head. The first test I ran showed "1090" as In capability. After changing the configuration of the 330ES, I ran the report and got what is attached showing DUAL in.

I am getting FIS-B weather. I see some aircraft, but it doesn't seem to be the full TIS-B picture. It seems to be functioning exactly as it did before we got the ADSB install. 

The 182 that I used to fly frequently is ADSB-out compliant as well. When I would fly it, I would get the antenna icon illuminated and see TIS-B traffic. I have also wondered if the GDL or Pilot have somehow latched onto that plane, and it's looking only for that plane as ownship. I feel like I'm grasping at straws with that thought.

 

Thanks everyone for all the help so far!

 

PAPR_20170123_A0323F_33477743.pdf

Based on the full report, it sure looks like the FAA sees the "in" portion as "dual". If you are not receiving full TIS-B, I'm still wondering if it is a problem with your GDL-39 or like thinwing suggests, an issue with antenna location. 

[PaulM]

The report looks good, and the SDA is 2.. so that should provide the TIS-B rebroadcast data. 

What does the "status" ADS-B page look like in Garmin pilot? 

https://www.pilotsofamerica.com/community/threads/ads-b-in-tracking-own-aircraft.77805/

It has lines for ownship detection.   that data should match your transponder + N#.  (I'm a stratus 1+ foreflight user)  

[AaronDC8402]

50 minutes ago, PaulM said:

The report looks good, and the SDA is 2.. so that should provide the TIS-B rebroadcast data. 

What does the "status" ADS-B page look like in Garmin pilot? 

It shows connection to ground stations, but no ownship detection or TIS-B. 

I'll take some screen captures the next time I'm flying. Should be tomorrow.

[AaronDC8402]

I failed at taking proper screen captures from the tablet. Instead, I took a picture with my phone. Same end result, I guess.

Sure looks to me like the GDL is picking up ground stations, and the GDL seems to be talking to the tablet correctly. Pilot is reporting our plane as a traffic target. Notice that it's reporting 1ZX's altitude as +195 (19,500 ft above) relative to wherever Garmin Pilot thinks it is. Knowing that ownship detection algorithm is based on detecting a target within a certain distance (position and altitude), I think the issue might be the altitude discrepancy. Even though I'm reporting UAT in capability, the returned "hockey puck" is only for 3500 ft above and below. If Pilot thinks were 15,000 ft below sea level, nothing will ever get reported back.

I'll send this stuff back to the Garmin tech support guy that I've been emailing with as well. Maybe he can figure something out from here. I don't know where the altitude reference comes from. Garmin pilot shows GPS altitude reasonably correct (which should be coming from the GDL's GPS). The GTX is reporting correct altitude. Maybe it's just a glitch in the Garmin Pilot app.

[AaronDC8402]

Also meant to mention, we had another (slightly newer) Android tablet in the plane also connected to the GDL. Same result on that tablet.

 

[ArtVandelay]

I don't get what you are saying about being below sea level, the target +19500 above you?

Here is my screen capture, notice I have full TISB coverage

[AaronDC8402]

The target it says is 19,500 ft above me IS my aircraft.

Edited January 29, 2017 by AaronDC8402
typo

[cnoe]

It's been 3 years ago so my memory is fuzzy but there is a setting in the 330ES software that needs to be set properly telling the ground stations you are both transmitting and receiving ADS-B, even if your "in" equipment isn't certified (i.e. iPad). If not set correctly the towers will not broadcast to you as desired. Been there/done that, but with a GTX330ES/Foreflight/Stratus combo. Works perfectly when configured properly.


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