[jquayle]

Purchased a new to me RV-7 a few months ago and I'd noticing that traffic would drop on my MFD. I have a GDL 39 remote connected to the system and wasn't sure if there was a problem with the GDL or perhaps connectivity in the G3X.

I'm currently on 9.31 firmware, but say this same behavior with the previous version (9.21? I don't recall exactly)

Reached out to Garmin and received an email that they have seen this in other systems. Wondered if anyone else out there is having this issue as well and if perhaps someone found a solution. Also, I'm not sure if it's something specific with the GDL 39 and G3X and not happening with other ADS-B devices.

Here's the email from Garmin:

"Hi Jeff,

I've been seeing issues with G3X Touch systems where the traffic randomly drops off the G3X, but remains on connected iPads, etc. Engineering is looking into it.

You could test this by connecting a phone or tablet running Garmin Pilot (there's a free trial version, they tell me) or Foreflight to the GDL 39 and see if the traffic remains on the app when it drops off the G3X... if it does, then it's a G3X problem (likely software). "

I emailed back and informed her that I did still receive traffic via ADS-B on my iPad in Foreflight when it would disappear on the G3X.


-Jeff

 

[sbalmos]

So you have an older GDL 39 that is Bluetooth'd to your MFD? But you still receive traffic via the iPad Bluetooth. Interesting. I have nearly the same behavior. Except I have a GDL 52 that is serial-wired to my PFD and MFD. Same thing where certain predictable parts of my local flying region drop traffic. I have yet to test with my iPad though.

I also reported to Garmin a few months ago, and their note was that my name's been added to the internal Engineering tracking ticket. Seems to imply they're gathering common threads (equipment, s/w versions, etc) across multiple similar reports.

You're not alone on this one.

 

[g3xpert]

Traffic Loss

Good Afternoon,

We have been able to replicate some of the reported behavior described in this thread and are currently working to resolve the issue. We will update the group here, as soon as an update is available.

Thanks,

Justin

 

[jquayle]

So you have an older GDL 39 that is Bluetooth'd to your MFD?

No, I have the GDL 39R, which is a remote unit, that I believe is connected via serial to the G3X and I connect to it bluetooth via the iPad.

https://www.garmin.com/en-US/p/539942


-Jeff

 

[MarkW]

I also have been seeing a larger than normal drop of traffic.
It will be interesting to see What Garmin comes up with.

I will update with config as this thread might continue.

Dual GDU 370, GDL39R, GTX23ES no bluetooth.
Been flying this combo since 2013

 

[jbDC9]

I've been seeing issues with G3X Touch systems where the traffic randomly drops off the G3X, but remains on connected iPads, etc. Engineering is looking into it.

You could test this by connecting a phone or tablet running Garmin Pilot (there's a free trial version, they tell me) or Foreflight to the GDL 39 and see if the traffic remains on the app when it drops off the G3X... if it does, then it's a G3X problem (likely software). "

I emailed back and informed her that I did still receive traffic via ADS-B on my iPad in Foreflight when it would disappear on the G3X.

Weird. I have the exact opposite issue with my GNX375; the traffic display on the 375 and to my wired/Bluetoothed Aera 660 is always rock solid, but when I Bluetooth connect the 375 to either of my Android tablets running Garmin Pilot, the traffic display on the tablet is very random and intermittent. I also have an iPhone running GP, but haven’t yet connected it to see the traffic display; methinks I oughta do that on my next flight to see if that narrows it down. But, I’ve used my two Android tablets in other ships using both Flightstream and GDL52 data and the traffic display is rock solid. Seems to be a glitch with my 375, but what it is, I dunno…

 

[mburch]

I have the exact opposite issue with my GNX375; the traffic display on the 375 and to my wired/Bluetoothed Aera 660 is always rock solid, but when I Bluetooth connect the 375 to either of my Android tablets running Garmin Pilot, the traffic display on the tablet is very random and intermittent.

You may be interested in this service bulletin for the GNX 375:

Fixed an issue where the traffic output via Bluetooth interface to non-Garmin PED was interrupted when 27 or more traffic targets were present. Now traffic data is always output.

 

[jbDC9]

You may be interested in this service bulletin for the GNX 375:

Well isn't that interesting and timely... will try to update this afternoon. Thanks Matt!

 

[Ed_Wischmeyer]

I may have seen the similar dropouts with a GDL52 hardwired to dual G3X Touch screens. No SiriusXM nor Bluetooth connections.

 

[AaronG]

I have the same issue with the G3X and GDL50 combo. I fly the same route for years regularly with no issue, until about 6 months ago. Suddenly it loses traffic for about 1/2 the flight. The location of loss isn’t even consistent flight to flight. It seems to have started with the latest software upgrade.

I lose traffic on the G3X, but it continues to work on ForeFlight. The weather continues to work on both. I tried to connect the G3X to the GDL50 via Bluetooth like ForeFlight, but still doesn’t work on G3X. I do have a Garmin 330 also providing traffic to G3X so was wondering if that was causing an issue with latest G3X software.

I put in a ticket with Garmin about 2 months ago, but keep getting told it’s in the queue. This could be a safety issue, so hoping they get it resolved shortly.

 

[Longez]

I have the same issue with the G3X and GDL50 combo. I fly the same route for years regularly with no issue, until about 6 months ago. Suddenly it loses traffic for about 1/2 the flight. The location of loss isn’t even consistent flight to flight. It seems to have started with the latest software upgrade.

I lose traffic on the G3X, but it continues to work on ForeFlight. The weather continues to work on both. I tried to connect the G3X to the GDL50 via Bluetooth like ForeFlight, but still doesn’t work on G3X. I do have a Garmin 330 also providing traffic to G3X so was wondering if that was causing an issue with latest G3X software.

I put in a ticket with Garmin about 2 months ago, but keep getting told it’s in the queue. This could be a safety issue, so hoping they get it resolved shortly.

How do you have the displayed traffic Altitude Range configured? As explained in the Pilot's Guide, all settings except Unrestricted will declutter the display by removing some out-of-altitude-range traffic.

Altitude Range Choices:
• Above: Displays non-threat and proximity traffic from 9,000 feet
above the aircraft to 2,700 feet below the aircraft. Typically used
during climb phase of flight.
• Normal: Displays non-threat and proximity traffic from 2,700 feet
above the aircraft to 2,700 feet below the aircraft. Typically used
during enroute phase of flight.
• Below: Displays non-threat and proximity traffic from 2,700 feet
above the aircraft to 9,000 feet below the aircraft. Typically used
during descent phase of flight.
• Unrestricted: All traffic is displayed.

Unless I am in a very busy area, I always use Unrestricted. I rarely see traffic out the window that I didn't first see on the moving map of my G3X Touch system with GDL 52R traffic receiver.

I recommend you disable GTX 330ES provided TIS-A traffic as it is very low value compared to ADS-B traffic. You never want your G3X Touch system to use TIS-A traffic over ADS-B traffic.



Steve

 

[mrj22]

Same Issue

I have been having the same issue for the last few months. GDL39 hard wired to the G3x with GTX23 transponder. Traffic works fine on the ipad.

 

[sailvi767]

If you disable TIS-A traffic you will not see transponder only aircraft or aircraft with a inop ADSB out. That is probably a small percent of current traffic but you will be blind to those aircraft in areas with radar coverage.

 

[Longez]

If you disable TIS-A traffic you will not see transponder only aircraft or aircraft with a inop ADSB out. That is probably a small percent of current traffic but you will be blind to those aircraft in areas with radar coverage.

That is incorrect.

ADS-B ground stations uplink TIS-B traffic (transponder equipped non-ADS-B Out aircraft in radar coverage) so those of us with ADS-B traffic receivers can see those aircraft.

Aircraft which show up as traffic on the map with no Flight ID are TIS-B aircraft which have been uplinked by ground stations.

Dual frequency Garmin ADS-B receivers (all of them) see all ADS-B Out equipped targets directly with no ground station support. No ADS-R help needed.

Steve

 

[jquayle]

G3Expert - Please let us know if you'd like those of us with the issue to provide a list of components if you think it might only be effecting people with specific configurations.


JQ

GDU 460
GDU 465
GTX 23ES
GDL 39R
Firmware 9.31

 

[bjdecker]

...You never want your G3X Touch system to use TIS-A traffic over ADS-B traffic...

Steve,

Completely agree.

However, I can see where/how to turn off TIS-A (GTX 330ES RS-232 Output - "Remote + TIS-A") but no option for the G3X to prioritize it or display it at all...I'm missing the easter-egg...

B

 

[ronrapp]

Purchased a new to me RV-7 a few months ago and I'd noticing that traffic would drop on my MFD. I have a GDL 39 remote connected to the system and wasn't sure if there was a problem with the GDL or perhaps connectivity in the G3X.

For whatever it's worth, I have this same configuration (G3X Touch, GDL 39 traffic via bluetooth) and the exact same problem in my RV-6.

I've got a single GDU460 with an iPad serving as a secondary screen on the right side of the panel. Using either Foreflight or Garmin Pilot, traffic usually remains on the iPad, but will disappear from the GDU460 entirely. It says "Traffic failed" and the bluetooth connection to the GDL39 drops. Once this happens, it will not reconnect to the G3X for the rest of the flight.

--Ron

 

[lr172]

Purchased a new to me RV-7 a few months ago and I'd noticing that traffic would drop on my MFD. I have a GDL 39 remote connected to the system and wasn't sure if there was a problem with the GDL or perhaps connectivity in the G3X.

I'm currently on 9.31 firmware, but say this same behavior with the previous version (9.21? I don't recall exactly)

Reached out to Garmin and received an email that they have seen this in other systems. Wondered if anyone else out there is having this issue as well and if perhaps someone found a solution. Also, I'm not sure if it's something specific with the GDL 39 and G3X and not happening with other ADS-B devices.

Here's the email from Garmin:

"Hi Jeff,

I've been seeing issues with G3X Touch systems where the traffic randomly drops off the G3X, but remains on connected iPads, etc. Engineering is looking into it.

You could test this by connecting a phone or tablet running Garmin Pilot (there's a free trial version, they tell me) or Foreflight to the GDL 39 and see if the traffic remains on the app when it drops off the G3X... if it does, then it's a G3X problem (likely software). "

I emailed back and informed her that I did still receive traffic via ADS-B on my iPad in Foreflight when it would disappear on the G3X.


-Jeff

I am the other guy that pushed this and got it sent to engineering. It is random and sporadic and has been going on for me for several years. Two different GDLs and several different sw releases. It is not the ground station. I get it just as much near Ohare is I do in the middle of nowhere.

 

[torquen]

Hello all, I came across this thread because I also have a G3X pfd and mfd that is cutting traffic.
I will be flying along with lots of traffic on the screen when it all suddenly disappears. I can pull up my phone or iPad which is running the adsb “in” via Bluetooth through my GDL39. The traffic still appears 100% on the iPad and iPhone using foreflight.
I have updated to the newest software and continue to have the problem.

I have a 1 hr flight where I collected the date and sent it to Garmin. They told me they are aware of the issue of GDL systems talking to G3X systems and showing adsb traffic. I have also sent them video and pictures where the traffic would disappear or reappear and then an instant pan over to the phone or iPad showing it still works.

My GDL39 is the remote system. It’s hard wired into my G3X. I have tried to blue tooth my G3X to the GDL39 and still have the adsb traffic loss.

Hopefully this gets figured out soon as it’s definitely an issue. My adsb out is working perfectly and I’ve run several reports and sent this info to Garmin as well.

I have recently loaded two software versions back to see if the issue would go away. 9.14 did nothing different than 9.22 or 9.31.

Anyone have a solution yet? If you are having this issue make sure to call Garmin and let them know.

 

[sinjin]

add me to the list of G3X with GDL 51 and random traffic drop out. traffic keeps working on my phone/ipad.

 

[torquen]

add me to the list of G3X with GDL 51 and random traffic drop out. traffic keeps working on my phone/ipad.

Make sure you call Garmin and let them know. As shown on here some have experienced this for years so they need to know how much we need this to be a priority for them to fix.
They told me they don’t know how to fix it. So the next step is to have them support us with equipment that will replace the gdl if they are having so many problems.

 

[lr172]

add me to the list of G3X with GDL 51 and random traffic drop out. traffic keeps working on my phone/ipad.

We all need to individually push garmin to address this. It took me over a year to get them to accept it was an issue nad likely because I was the only one complaining. If numerous people open cases on this flaw, they are more likely to put resources on it to address it.

Larry

 

[Bill.Peyton]

Just as another data point…. I have had this issue with all versions of software and with both the gdl39 and the gdl52 with both the G3x non touch legacy and the G3X touch, and with 3 different transponders. This has been ongoing for at least 10 years. Most times removing power to reboot the receiver re-establishes the traffic. Traffic is never gone more than a couple of minutes and it’s always ground based uplinks that drop out. Both xm and ADSB Wx always comes through.

 

[Jeffblak]

I’m having the same issue, my system is:
GDU460 with RS232 connection to a GDL-39R, and a GDU-465 connected to the same GDL with Bluetooth. Both connections fail at the same time for a couple of minutes, then come back on. It can be alarming. I also have a GTX-23-ES transponder using a GPS-175 as the ADSB out position source. I was going to try a new GDL-50, but after reading this thread I’m considering scrapping the GDL and going with an ADSB in/out transponder, the GTX-45R.

 

[AaronG]

I have continued to troubleshoot this for the last 6 months. I continue to think it is a software issue since I had zero issues until upgrading to the latest software and now it happens on most flights. On the last flight I verified in the menu that I was receiving a ground signal from 10 different stations, so not a lack of ground stations. Was also still getting weather on the G3X plus traffic on the iPad. I have a GDL52 hardwired to the G3X. Tried Bluetooth connection to G3X like the iPad but still no traffic on G3X. One day in the same location and altitude it works, the next day it doesn’t.

One item that did help me was turning off GTX330 TIS-A on the GTX330. When this issue happens, the G3X reverts to the TIS-A and all air-to-air ABS-B traffic drops as well. So if you have TIS-A, turn it off and you will still get air-to-air ADS-B. For me, that still allows me to see almost all the traffic, since most planes have ADS-B out in the Northeast.

 

[AaronG]

As I think about this more … is it possible that our iPads are only showing air-to-air traffic, and the G3X doesn’t because it is being inhibited by TIS-A. So the GDL receivers are dropping traffic from the ground signal, but the iPads seem to still work because they are showing air-to-air only.

Does anyone drop traffic on the G3X and get it on the iPad, and not have a TIS-A device like a GTX330 or GTX-23?

 

[lr172]

Just as another data point…. I have had this issue with all versions of software and with both the gdl39 and the gdl52 with both the G3x non touch legacy and the G3X touch, and with 3 different transponders. This has been ongoing for at least 10 years. Most times removing power to reboot the receiver re-establishes the traffic. Traffic is never gone more than a couple of minutes and it’s always ground based uplinks that drop out. Both xm and ADSB Wx always comes through.

exact description for my symptoms also. Will add that always have 4 bars of ground reception strength with many nearby ground stations. when it happens.

 

[lr172]

I’m having the same issue, my system is:
GDU460 with RS232 connection to a GDL-39R, and a GDU-465 connected to the same GDL with Bluetooth. Both connections fail at the same time for a couple of minutes, then come back on. It can be alarming. I also have a GTX-23-ES transponder using a GPS-175 as the ADSB out position source. I was going to try a new GDL-50, but after reading this thread I’m considering scrapping the GDL and going with an ADSB in/out transponder, the GTX-45R.

The GDL feeds both my ipad and the G3X and ONLY the G3X drops the grd based traffic (never loses air to air). This a S/W bug in the G3X (or possibly the core transmit SW in the GDL) so your approach above is not likely to help. Save the $ and simply help us apply more pressure to Garmin to address this. It is obviously highly intermittent and will not be easy for them to find.

Larry

 

[lr172]

As I think about this more … is it possible that our iPads are only showing air-to-air traffic, and the G3X doesn’t because it is being inhibited by TIS-A. So the GDL receivers are dropping traffic from the ground signal, but the iPads seem to still work because they are showing air-to-air only.

Does anyone drop traffic on the G3X and get it on the iPad, and not have a TIS-A device like a GTX330 or GTX-23?

I have TIS-a turned off. I have confirmed that when this happens that the ipad is still getting grd based traffic. This happened on trip with only two or three other planes near me. One dropped off the G3X and I looked over at the Ipad and it was still there and stayed there. Confirmed the greyed out ground tag on the info page. It then popped back on the G3X a minute or two later and Ground tag turned white again. I have done this several times trying to prove the issue to Garmin.

TIS data is received by the transponder and ADSB data is received by the GDL and both have separate paths to the G3X. Also TIS-a coverage is very low today and NEVER used outside of approach airspace. I have observed this error in at least 20 different states, most of which have no TIS-a coverage.

Larry

 

[bjdecker]

Larry -- have you looked at your PAPR recently? January 5th's flight specifically -- note TIS-B Client %. Given your route of flight and proximity to ground stations/towers this should be closer to 100%.

I ran into this exact same issue in Central TX 4+ years ago; essentially TIS-B client data was being ignored by the GTX/GDL because of a fault in the data stream from the FAA. Resolved with a site-specific SW update from the ADS-B system contractor. Only took 38 emails, 5 phone calls to get to root cause and resolution.

Ed Wischemeyer had similar issues operating out of the KSAV area and was invaluable in providing FAA contacts.

Cheers!

B

 

[Jeffblak]

Larry,
I will call Garmin Aviation on Monday and open a case.

 

[bjdecker]

@jquayle , @AaronG, @Jeffblak -- Same question - Have you looked at your PAPR for your N-number?

Pay attention to the TIS-B Client % number on the second page.

For a flight in and around a Class B airport, this # should be really high -- close to 100%. For a cross country trip across Nevada and California I would expect a lower % -- probably in the 80 - 90% range; depending upon geography and altitude.

From where I sit, it looks like the issue I chased down in 2019 is back.


B

 

[lr172]

Larry -- have you looked at your PAPR recently? January 5th's flight specifically -- note TIS-B Client %. Given your route of flight and proximity to ground stations/towers this should be closer to 100%.

I ran into this exact same issue in Central TX 4+ years ago; essentially TIS-B client data was being ignored by the GTX/GDL because of a fault in the data stream from the FAA. Resolved with a site-specific SW update from the ADS-B system contractor. Only took 38 emails, 5 phone calls to get to root cause and resolution.

Ed Wischemeyer had similar issues operating out of the KSAV area and was invaluable in providing FAA contacts.

Cheers!

B

Yes, I have run the PAPR reports a couple times because I had traffic disappearing across the board and assumed that was an FAA issue. However, the problem discussed here is different. The GDL is receiving ground based traffic data and is successfully sending that traffic data to both the Ipad and the G3X for display. When the problem occurs, the ipad successfully shows the air to air and the ground based traffic, but the G3X does not; only the air to air traffic. Either the SW in the MFD is losing it's way or the SW in the GDL is successfully formatting it for the ipad but not for the G3X. If this were related to the client %age, both the ipad and the G3X would lose the traffic and I ahve confirmed several times, that the ipad shows traffic that the G3X does not. In theory anyways.

I suppose it is possible that there is some type of error in the format that foreflight successfully ignores, but the G3X does not. When this problem occurs, the traffic info page in the g3x indicates that it is no longer receiving ground based traffic (box turns from white to grey) even though I have 4 bars of receiving strength and the G3X is seeing 10+ ground stations. Didn't write the SW, so don't know what triggers that change.

Larry

 

[bjdecker]

Maybe - Possibly?

Here's a screen grab of what I was seeing -- Note, my setup is totally different, so this may/may not be a similar issue. I have dual G3x Touch, GTN 650xi, and a GTX 345. The GTX 345 is the primary receiver/interrogator/aggregator for ALL data services - TIS, FIS, ADSBxx.



The first symptom I noticed was the total lack of traffic in/around me BUT I could get a visual on them -- then I noticed the "White X" on the Little Tower Icon.

And Behold -- TIS-B Traffic Data was "No Service"



But I was receiving FIS-B weather and the Ground Uplink Signal was strong (4 bars). As I understand it, FIS-B (weather, etc.) is received on 978MHz and TIS-B is received on 1090MHZ and 978MHZ. The GTX 345 is a Dual Link receiver as is the GDL 39R, GDL 5xR.

...and here's the excerpt of the root cause from the FAA ADSB project office:

After receiving several independent pilot reports (and the associated details), we were able to determine that a recent ADS-B maintenance action caused a software anomaly that resulted in unreliable delivery of TIS-B “Service Status” messages in the region where you were flying. The avionics would then interpret the lack of the TIS-B Service Status message as the TIS-B Service being unavailable. However, the TIS-B Targets were still being sent by the ADS-B system and received by the avionics. The ADS-B maintenance procedures have been modified to eliminate the anomaly in the future.
....

Cheers,

B

 

[AaronG]

I get the exact same screens above when the traffic drops. Traffic on a recent 25 min flight was out half the time in busy New England with planes all around within a few miles. Just ran the report for that flight and it showed TIS-B client at 8.9% on page 2. At least 10 ground stations receiving. That sounds like a problem based on your emails.

 

[Jeffblak]

I ran the PAPR report for a flight yesterday where I lost all traffic for about 4 minutes. It showed the TIS-B client at 9.1 percent. I was at a lower altitude than I normally am, but that still feels like a low percentage.

 

[Bill.Peyton]

I am not convinced that it is a Garmin issue. I just created several PAPR reports, none of which show even close to 100% TIS-B client. When I look at my flights on Flightaware and ADS-B Exchange, I do not see any dropouts. I believe that both of the trackers use independent consumer ADS-B receivers. This also shows it is not a transponder issue. On the other hand, it appears that Foreflight continues to deliver ground based traffice received through the GDL's, and the G3X does not. I am using Garmin Pilot App, and when my G3X fails ground basedtraffic, so does Pilot app.

 

[torquen]

This is definitely a Garmin issue. Because I can fly with friends right next to me using Dynon and they have full traffic where my G3X does not. I can put foreflight up using a simple stratus receiver and have no issues and at the same exact time my G3X shows zero traffic.
I just flew into Halfmoon the other day and had to have my iPad mounted in the plane as well because the G3X has been so unreliable showing traffic. It can shut down for up to 10 mins from what I’ve come across in my plane.

Garmin is definitely aware it’s their problem and they have also been able to replicate this issue in their shop. I was told they just don’t have a fix for the issue.

Every single person needs to call Garmin and start barking up the tree.

I don’t think it’s in the GDL system because it will still work perfectly with anything else linked to it.
I believe it’s the G3x system not talking with the GDL.

I wish the g3x had the capability to receive WiFi so I could link my stratus to it and see if that was to work. But the g3x only talks through Bluetooth.

 

[bjdecker]

This is definitely a Garmin issue. Because I can fly with friends right next to me using Dynon and they have full traffic where my G3X does not. I can put foreflight up using a simple stratus receiver and have no issues and at the same exact time my G3X shows zero traffic.
I just flew into Halfmoon the other day and had to have my iPad mounted in the plane as well because the G3X has been so unreliable showing traffic. It can shut down for up to 10 mins from what I’ve come across in my plane.

Garmin is definitely aware it’s their problem and they have also been able to replicate this issue in their shop. I was told they just don’t have a fix for the issue.

Every single person needs to call Garmin and start barking up the tree.

I don’t think it’s in the GDL system because it will still work perfectly with anything else linked to it.
I believe it’s the G3x system not talking with the GDL.

I wish the g3x had the capability to receive WiFi so I could link my stratus to it and see if that was to work. But the g3x only talks through Bluetooth.

Garrett,

I ran a PAPR for your flight from Rio Vista to Half Moon Bay and see that the TIS-B client is only 34.5% -- Considering your route of flight (Golden Gate Bridge, Bay Area...) in and around the KSFO Class B, I would have expected closer to 100%....

You state that Garmin is aware of, but don't have a fix for this issue -- who did you speak with @Garmin and when?

Cheers!

B

 

[bjdecker]

...In addition to haranguing Garmin/G3Xpert about this issue suggest that each of you collect data and send FAA at this weblink

https://www.faa.gov/air_traffic/technology/adsb/adsb_reports/

 

[lr172]

Maybe - Possibly?

Here's a screen grab of what I was seeing -- Note, my setup is totally different, so this may/may not be a similar issue. I have dual G3x Touch, GTN 650xi, and a GTX 345. The GTX 345 is the primary receiver/interrogator/aggregator for ALL data services - TIS, FIS, ADSBxx.

View attachment 54975

The first symptom I noticed was the total lack of traffic in/around me BUT I could get a visual on them -- then I noticed the "White X" on the Little Tower Icon.

And Behold -- TIS-B Traffic Data was "No Service"

View attachment 54976

But I was receiving FIS-B weather and the Ground Uplink Signal was strong (4 bars). As I understand it, FIS-B (weather, etc.) is received on 978MHz and TIS-B is received on 1090MHZ and 978MHZ. The GTX 345 is a Dual Link receiver as is the GDL 39R, GDL 5xR.

...and here's the excerpt of the root cause from the FAA ADSB project office:

After receiving several independent pilot reports (and the associated details), we were able to determine that a recent ADS-B maintenance action caused a software anomaly that resulted in unreliable delivery of TIS-B “Service Status” messages in the region where you were flying. The avionics would then interpret the lack of the TIS-B Service Status message as the TIS-B Service being unavailable. However, the TIS-B Targets were still being sent by the ADS-B system and received by the avionics. The ADS-B maintenance procedures have been modified to eliminate the anomaly in the future.
....

Cheers,

B

Your problem is very similar to mine. However, I have had this on and off for a few years, so if the FAA addressed this issue I should have seen an improvement. When did you receive this note? This would make a lot of sense, as maybe the G3X honors the status and FF doesn't. However, it does not address how this problem appears and disappears at random. On any given x ctry flight, it may happen 5 times over a 30 minute period and then behave normally for hours.

Larry

 

[lr172]

This is definitely a Garmin issue. Because I can fly with friends right next to me using Dynon and they have full traffic where my G3X does not. I can put foreflight up using a simple stratus receiver and have no issues and at the same exact time my G3X shows zero traffic.
I just flew into Halfmoon the other day and had to have my iPad mounted in the plane as well because the G3X has been so unreliable showing traffic. It can shut down for up to 10 mins from what I’ve come across in my plane.

Garmin is definitely aware it’s their problem and they have also been able to replicate this issue in their shop. I was told they just don’t have a fix for the issue.

Every single person needs to call Garmin and start barking up the tree.

I don’t think it’s in the GDL system because it will still work perfectly with anything else linked to it.
I believe it’s the G3x system not talking with the GDL.

I wish the g3x had the capability to receive WiFi so I could link my stratus to it and see if that was to work. But the g3x only talks through Bluetooth.

+1

Again I will state that at the time that the G3X stops dsiplaying grd based traffic, foreflight is accurately showing that traffic. The data is all sourced from the same GDL receiver, so IT HAS TO BE a Garmin SW issue, regardless of the TIS B %age on a PAPR report. If the FAA stopped sending the TIS b data, I would NOT see it on FF. As I have said, I have spent hours on the phone with Garmin and they accept that it is their issue. Just not putting enough resources on it to address it. Maybe a quick note to the garmin attorneys may help. I imagine if they started thinking about the liability associated with an air to air incursion due to their traffic not working might wake them up.

 

[lr172]

Garrett,

I ran a PAPR for your flight from Rio Vista to Half Moon Bay and see that the TIS-B client is only 34.5% -- Considering your route of flight (Golden Gate Bridge, Bay Area...) in and around the KSFO Class B, I would have expected closer to 100%....

You state that Garmin is aware of, but don't have a fix for this issue -- who did you speak with @Garmin and when?

Cheers!

B

But none of use really understand what this metric means, so we cannot reliably use it to decide whether or not it is the cause. Lets say that it is 50%. That could mean that it simply stops transmitting for 1 second then starts transmitting for 1 second, then repeats the cycle. That is 50% availability and you and I would be none the wiser of it. I see this a lot, where a traffic target that I am tracking drops off the screen and comes back 10 seconds later. I have always assumed that there was a hiccup in the FAAs system in these cases. This type of error is totally different than the problem we are discussing here.

We must remember that our systems are vitrually moving the target on our map, baeed upon the last transmissions track and velocity. They are getting updates on the traffic every few seconds, but in between those they are using the last transmissions data. The system is not dependant upon high refresh rates and therefore difficult for us to know when the system stops transmitting for a few seconds. It is also possible that the garmin systems sees these interuptions and takes the TIS b offline, while Dynon FF and others all just keep humming along and waiting for the next transmission. This actually makes some sense, as Garmin is BEYOND conservative with these types of things compared to others.

Larry

 

[lr172]

. I am using Garmin Pilot App, and when my G3X fails ground basedtraffic, so does Pilot app.

That could simply mean that the garmin pilot uses the same source code base in the G3X and the PIlot and therefore choke in the same manner. As I mentioned, I use the G3X and foreflight. EVERY TIME the G3X losses grd based traffic, FF shows it reliably and both systems get a feed from the same GDL. However, the data goes via RS-232 to the G3X and bluetooth to the IPAD or it could be code in the GDL that is having issues in the serial xmit section.

 

[Jeffblak]

A close friend of mine has the same aircraft and avionics package that I do, except that his being a few years newer has the GTX-45R instead of a GDL-39R and GTX-23-ES. I looked at a 30 minute flight he made recently and his TIS-B client was 0%. On that flight his traffic display on both G3X screens was working normally, with plenty of traffic displayed and no drop outs. I assume this was via aircraft to aircraft ADS-B. He has never experienced a drop out, which make me think this is a problem with the GDL units. It may actually be a problem with the aircraft to aircraft reception or processing, so that when TIS-B is lost so is all traffic.

 

[lr172]

A close friend of mine has the same aircraft and avionics package that I do, except that his being a few years newer has the GTX-45R instead of a GDL-39R and GTX-23-ES. I looked at a 30 minute flight he made recently and his TIS-B client was 0%. On that flight his traffic display on both G3X screens was working normally, with plenty of traffic displayed and no drop outs. I assume this was via aircraft to aircraft ADS-B. He has never experienced a drop out, which make me think this is a problem with the GDL units. It may actually be a problem with the aircraft to aircraft reception or processing, so that when TIS-B is lost so is all traffic.

This problem doesn't always result in drop outs, as a lot of traffic is air to air. He needs to go to the traffic page and observe the color of the box labelled grd traffic.

 

[bjdecker]

Your problem is very similar to mine. However, I have had this on and off for a few years, so if the FAA addressed this issue I should have seen an improvement. When did you receive this note? This would make a lot of sense, as maybe the G3X honors the status and FF doesn't. However, it does not address how this problem appears and disappears at random. On any given x ctry flight, it may happen 5 times over a 30 minute period and then behave normally for hours.

Larry

This was identified in October 2019 and applied to the coverage area/service volume in an around a specific tower. There was a problem in a data link to a tower that resulted in TIS-B not being transmitted in the data stream on 1090MHz to the aircraft within that tower's coverage. Air-to-Air worked fine and if you flew into another area you would pick up valid TIS-B and traffic would re-appear. Problem was fixed in November 2019 but it was site specific per the ADSB Contractor (we had a little after-action review/design review with the FAA, the contractor and a couple of other interested parties.)

The TIS-B Client metric in the PAPR is the amount of time a particular flight is in receipt of valid TIS-B data; It's a "Tell us we're good" report. A low percentage of TIS-B is indicative of the Aircraft/Client NOT receiving TIS-B data -OR- the TIS-B data received isn't valid.

Text is an inaccurate/incomplete means of communication at times, but I sense some frustration and I don't mean to be the cause -- just trying to help.

Good Luck,

B

 

[torquen]

Garrett,

I ran a PAPR for your flight from Rio Vista to Half Moon Bay and see that the TIS-B client is only 34.5% -- Considering your route of flight (Golden Gate Bridge, Bay Area...) in and around the KSFO Class B, I would have expected closer to 100%....

You state that Garmin is aware of, but don't have a fix for this issue -- who did you speak with @Garmin and when?

Cheers!

B

I’ve spoken to several people in the G3X side. The only name I remember would be Savanna. All have informed me that I am on the ticket and will be notified when the issue is resolved.

Today I flew to Petaluma and back. I borrowed my buddies GDL 50. We blue toothed the g3x to his gdl 50 and my iPad to my gdl 39r.

Even with his gdl50 the g3x was dropping traffic. My iPad running on my gdl39r was perfect and his iPad running on his gdl50 using the garmin program worked perfectly.

A friend of mine was flying next to me. He was only running a transponder. When the traffic would disappear his plane would still show up but no tail number or anything. Just the diamond.

 

[torquen]

+1

Again I will state that at the time that the G3X stops dsiplaying grd based traffic, foreflight is accurately showing that traffic. The data is all sourced from the same GDL receiver, so IT HAS TO BE a Garmin SW issue, regardless of the TIS B %age on a PAPR report. If the FAA stopped sending the TIS b data, I would NOT see it on FF. As I have said, I have spent hours on the phone with Garmin and they accept that it is their issue. Just not putting enough resources on it to address it. Maybe a quick note to the garmin attorneys may help. I imagine if they started thinking about the liability associated with an air to air incursion due to their traffic not working might wake them up.

I agree with you 100%. Todays flight had my GDL39r, my G3x, my iPad, my buddies GDL 50, his iPad running Garmin.

G3x failed several times for quite a while. Both iPads running foreflight and Garmin had traffic 100% of the time off of two separate gdl’s.

I have also sent several emails over to Garmin as well as several phone calls. At least two of the g3xperts have said they are definitely aware of the problem and have engineers trying to solve the issue but there is not a fix. They also said they were able to replicate the issue. In their facility.

Definitely frustrating when your buddies have a simple uavonics tailbeacon and get adsb just fine.

 

[lr172]

This was identified in October 2019 and applied to the coverage area/service volume in an around a specific tower. There was a problem in a data link to a tower that resulted in TIS-B not being transmitted in the data stream on 1090MHz to the aircraft within that tower's coverage. Air-to-Air worked fine and if you flew into another area you would pick up valid TIS-B and traffic would re-appear. Problem was fixed in November 2019 but it was site specific per the ADSB Contractor (we had a little after-action review/design review with the FAA, the contractor and a couple of other interested parties.)

The TIS-B Client metric in the PAPR is the amount of time a particular flight is in receipt of valid TIS-B data; It's a "Tell us we're good" report. A low percentage of TIS-B is indicative of the Aircraft/Client NOT receiving TIS-B data -OR- the TIS-B data received isn't valid.

Text is an inaccurate/incomplete means of communication at times, but I sense some frustration and I don't mean to be the cause -- just trying to help.

Good Luck,

B

Your data has been helpfull and appreciated. No frustration from me on your input here. I am however convinced that my specific problem is not related to the above type of problems, given that one of my devices receiving the data displays traffic that the other does not, so has to be in the receiving system and not an FAA transmission problem. Though I do have concerns that the TIS data is getting flawed or dropping out and the problem is that the Garmin is too conservative and shutting down, while every other system is just rolling along and catches up on the next good piece of data.

My theory is that the client %age drops to a low level, so the systems start seeing longer lags between transmissions from the station. They all likely have some SW that sets a time limit on when they should drop a target based upon not receceiving a future update. This is why we occasionally see a target disappear and then reappear in 20 seconds. I think that Garmin went over the top here and put another layer of "safety" on top of this and when they see too many flaws, they flag the TIS-B receiving function as flawed and they just shut down the whole TIS-B receiving function until the SW views it as stable again. Garmin tends to take this approach a lot due to too much litigation fear. Their approach seems to be that if it works we use it, but if we have concerns that it doesn't meet our standard, we won't let you use it.

Larry