GTX 345 failed in flight

C

Carolinaflyer

Filing Flight Plan
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Carolinaflyer
Shortly after TO this afternoon the 345 gave me a message ( best as I remember) “lost 1090ES signal”. I cycled power off and on a couple of times, but to no avail. Any ideas what this could be? Also, and most likely unrelated, it has not been sending traffic and weather to ForeFlight for the last couple flights. I’ve rebooted FF but that hasn’t helped.
Low time pilot and slightly challenged on these types of issues. I tend to understand things that can mash my hands, not so much with electrical-communication magicy things. Any insight would be greatly appreciated.
 
IDK man but that's concerning, mine failed out of the box soon as they installed it. Getting a different unit. Hope they don't have quality control issues with them.
 
Ask your avionics shop that installed it. Has to still be covered under warranty, no?
 
Those two issues are certainly related.
The 1090ES signal is for ADS-B.
In theory, the GPS should have continued to work just fine, but without 1090ES, no traffic or weather.
 
Sounds like it's time to call 1-800-garmin. Get out the credit card...:eek:
 
Avionics shop. Can be anything from the antenna connection crapped out to an internal failure of the receiver.
 
I occasionally loose traffic ADSB and TIS-B, but ATC sees me just fine. I’ve contacted the Garmin experts and thy gave me a few things to check next time I’m at the plane and get back to them. It appears I’m loosing my Data Link, as the ICON GOES DARK and the Bluetooth connection drops.
 
Had a student with the similar issue in his plane. Ended up being the encoder. Maybe check that.
 
On our 345 install the ADSB-OUT, XPDR and ADSB-in all share the same antennae (at least that's how I understand it). I can easily see a failure to receive 1090ES if you are too low to receive a ground station or the GBT you normally receive has went off line. But in that case it (345) can't know it's gone if it (345) can't see it to start with.

So it has me wondering if they listen back in on the ADSB-OUT when it is being sent? If I was designing that box I would as you can then know if you are TX since you also have a RX included. Maybe there is a internal RX error that it can self detect during each 1sec squit.

You could try this. All flights above about 750agl show up on Flight Aware within a minute or so after landing. Lookup your tail number on flight aware and see if you were indeed tracked. This may not work in a more rural or remote area.

Either way I don't think any of us can help you fix it. Maybe the flight aware piece will help the installer. But they can test the thing much better in the plane and on the bench.

Our issue was COM tx causing GPS signal loss.

I would think if your encoder pooped you'd no longer see pressure altitude displayed on the 345 screen.
 
Sinistar said:
On our 345 install the ADSB-OUT, XPDR and ADSB-in all share the same antennae (at least that's how I understand it). I can easily see a failure to receive 1090ES if you are too low to receive a ground station or the GBT you normally receive has went off line. But in that case it (345) can't know it's gone if it (345) can't see it to start with.

So it has me wondering if they listen back in on the ADSB-OUT when it is being sent? If I was designing that box I would as you can then know if you are TX since you also have a RX included. Maybe there is a internal RX error that it can self detect during each 1sec squit.

You could try this. All flights above about 750agl show up on Flight Aware within a minute or so after landing. Lookup your tail number on flight aware and see if you were indeed tracked. This may not work in a more rural or remote area.

Either way I don't think any of us can help you fix it. Maybe the flight aware piece will help the installer. But they can test the thing much better in the plane and on the bench.

Our issue was COM tx causing GPS signal loss.

I would think if your encoder pooped you'd no longer see pressure altitude displayed on the 345 screen.
Click to expand...

Interesting- I did not see PA indicating on the display...

I was about 5000’ when I noticed that it wasn’t working. Bluetooth connection was fine. It’s weird because traffic and weather was working fine up to the last couple of flights and now this too.
To make it worse, this transponder was installed by the former owner in Aug 2018. I’ve owned the plane since April. Kinda doubt the hardware or install is still covered by warranty. At any rate it’s gonna be a few weeks before I can get it to an avionics shop. Hopefully it’s a bad antenna connection or some such.

The joys of ownership...

Thanks for the inputs.
 
Ummm. Maybe a silly question, but:
I’m based under a Class Bravo and therefore within the mode C veil. Do I need to do anything or contact anyone before taking the plane to the avionics shop?
 
Just remember. Pressure altitude isn't the default display on the 345, it's the squawk code so it my just be be fine.

Maybe you should just turn on the master, let the 345 start up. Cycle thru the few screens and look at the pressure altitude. Of course it could be stuck at field elevation but I would think if the unit or wire is bad it would look funny. Check to see if your tablet connects and maybe even remove the existing bluetooth entries and try again. I think there's a diagnostic screen in there as well.

Also, while taxing can you ask for a different squawk on the ground and see if they can pick it up. Just to make sure they're getting the XPDR and mode C info.

Otherwise I think you just need to call the tower and probably approach and let them know of the flight in advance.
 
Sinistar said:
Just remember. Pressure altitude isn't the default display on the 345, it's the squawk code so it my just be be fine.

Maybe you should just turn on the master, let the 345 start up. Cycle thru the few screens and look at the pressure altitude. Of course it could be stuck at field elevation but I would think if the unit or wire is bad it would look funny. Check to see if your tablet connects and maybe even remove the existing bluetooth entries and try again. I think there's a diagnostic screen in there as well.

Also, while taxing can you ask for a different squawk on the ground and see if they can pick it up. Just to make sure they're getting the XPDR and mode C info.

Otherwise I think you just need to call the tower and probably approach and let them know of the flight in advance.
Click to expand...

I will try some of the diagnostics you mentioned as soon as I get a chance. As for flying with a non functioning txponder, I should have been more clear. I’m based at a small, non towered field under the class B shelf. To be legal, do I need to do anything (ask permission) before flying to my avionics shop?
 
Carolinaflyer said:
I will try some of the diagnostics you mentioned as soon as I get a chance. As for flying with a non functioning txponder, I should have been more clear. I’m based at a small, non towered field under the class B shelf. To be legal, do I need to do anything (ask permission) before flying to my avionics shop?
Click to expand...

§91.215 ATC transponder and altitude reporting equipment and use.
(d) ATC authorized deviations. Requests for ATC authorized deviations must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:

(1) For operation of an aircraft with an operating transponder but without operating automatic pressure altitude reporting equipment having a Mode C capability, the request may be made at any time.

(2) For operation of an aircraft with an inoperative transponder to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made or both, the request may be made at any time.

(3) For operation of an aircraft that is not equipped with a transponder, the request must be made at least one hour before the proposed operation.
 
Your manual might have a hint as to whether your transponder failed or if it’s still working and something else is wrong.

Garmin might have even chosen the EXACT message you got as their example of how to tell the difference in said...

... manual...

With pictures.

Of that exact error message. :)

https://www.manualslib.com/manual/1250205/Garmin-Gtx-335-Series.html?page=31#manual

^ That was found in one Google query. “Garmin 345 error codes”. Manualslib was in the top five responses with a 2016 copy of the manual.

C’mon... when avionics have an error message you have to go get the official manual the avionics shop had to hand you to make the whole thing legal...

I did laugh when the manual used your exact message for the picture example though. :)
 
Okay, this is a bit fringe but here goes:

Let's say your install wasn't verified against the ELT transmitting (or retransmitting COM) and its takes out your GPS signal...this actually happened in ours.

So lets say your elt is on right now or coming on when you turn on the master (far fetched I suppose)...it could be taking out your gps input which will fail the ADSB-out but still let the transponder work. Could be the same if some other device is transmitting frequently as well.
 
Sinistar said:
Okay, this is a bit fringe but here goes:

Let's say your install wasn't verified against the ELT transmitting (or retransmitting COM) and its takes out your GPS signal...this actually happened in ours.

So lets say your elt is on right now or coming on when you turn on the master (far fetched I suppose)...it could be taking out your gps input which will fail the ADSB-out but still let the transponder work. Could be the same if some other device is transmitting frequently as well.
Click to expand...
You’re scaring me, man.
 
denverpilot said:
Your manual might have a hint as to whether your transponder failed or if it’s still working and something else is wrong.

Garmin might have even chosen the EXACT message you got as their example of how to tell the difference in said...

... manual...

With pictures.

Of that exact error message. :)

https://www.manualslib.com/manual/1250205/Garmin-Gtx-335-Series.html?page=31#manual

^ That was found in one Google query. “Garmin 345 error codes”. Manualslib was in the top five responses with a 2016 copy of the manual.

C’mon... when avionics have an error message you have to go get the official manual the avionics shop had to hand you to make the whole thing legal...

I did laugh when the manual used your exact message for the picture example though. :)
Click to expand...
Well that’s embarrassing. I shoulda thought of that. Thank you, sir.
 
JScarry said:
§91.215 ATC transponder and altitude reporting equipment and use.
(d) ATC authorized deviations. Requests for ATC authorized deviations must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:

(1) For operation of an aircraft with an operating transponder but without operating automatic pressure altitude reporting equipment having a Mode C capability, the request may be made at any time.

(2) For operation of an aircraft with an inoperative transponder to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made or both, the request may be made at any time.

(3) For operation of an aircraft that is not equipped with a transponder, the request must be made at least one hour before the proposed operation.
Click to expand...
Should have thought to check the FAR/AIM, too. Thanks for taking the time to school me.
 
Btw I got the word back on mine. It was a software/config issue. The transponder just wasn’t properly set up to take data from the encoder as I understood it. Either way not a defective unit, plane is back and everything works.
 
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