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ADS-B Out Failure

Amadeus

Well Known Member
I've searched the forum and might be missing it but I didn't see a thread on this. I was flying today and ATC informed me that I was not transmitting ADS-B data.

I have the dual G3X system (with GTX35R and GPS20A) and have been transmitting until now. Where should I begin troubleshooting?
 
First thing I'd do is to go on-line and request a PAPR (Public ADSB performance Report), just to make sure there really is a problem. Don't forget to enter the date in GMT (e.g. it might have been tomorrow!).
If that confirms an issue, I'd start by looking at the wiring. Since it appears your transponder is okay (they didn't complain?) look at the connection between the GPS and the transponder, make sure there isn't a loose pin, etc. Presumably no one has been playing with the RS232 settings (format, speed, etc.)
 
First thing I'd do is to go on-line and request a PAPR (Public ADSB performance Report), just to make sure there really is a problem. Don't forget to enter the date in GMT (e.g. it might have been tomorrow!).

The PAPR shows exceptions for SIL and SDA.

I have not yet performed the required move of the HIC module behind the PFD & MFD. Could this be the culprit?
 
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I've searched the forum and might be missing it but I didn't see a thread on this. I was flying today and ATC informed me that I was not transmitting ADS-B data.

I have the dual G3X system (with GTX35R and GPS20A) and have been transmitting until now. Where should I begin troubleshooting?
Jayson,

It is incorrect to state that you were not transmitting ADS-B Out data on your flight today. You were transmitting the entire flight.

The problem is that your GTX 35R was transmitting non-compliant SIL and SDA values of zero.

For an installation such as yours, this means that either the GTX 35R was not properly configured to receive and use GPS data from the GPS 20A, or the GPS 20A is not properly operating and/or connected to the GTX 35R.

Start by making sure you are using the latest G3X Touch software and that your GTX 35R is properly configured. Also make sure that the GPS 20A is properly operating and connected to the GTX 35R.

The GPS 20A should be your primary GPS shown on the GPS status (Info) page on the PFD/MFD.

Steve
 
I got an email from the FAA when my Cherokee ADS-B was non compliant. The unit is a FreeFlight 978Mhz transceiver. I ended up sending the unit back to the factory for software update and repair. My plane was put on a “no service” list until I got a sat PAPR. Then it automatically went back to the good guy list. I was trading emails with he FAA every step of the way.
 
I've searched the forum and might be missing it but I didn't see a thread on this. I was flying today and ATC informed me that I was not transmitting ADS-B data.

I have the dual G3X system (with GTX35R and GPS20A) and have been transmitting until now. Where should I begin troubleshooting?

If you have recently done a software update on the G3X system there is almost certainly an easy solution.

G3X Software 9.12 (and higher) added a new field on the transponder page that needs to be configured for ADS-B compliance to be maintained.

To do this:

1. Hold the menu button down on the G3X PFD while the screen is booting up to put the system into configuration mode.

2. Scroll down and select the "Transponder" page

3. Scroll down and find the field named "position integrity". This is the newly added field. It will be defaulted to "Auto"

4. Change "auto" to "IFR GPS 1e-7". This is the correct setting to make your GTX-35R+GPS-20A ADS-B compliant again.
 
Whoops - Missed that 9.14 fixes this issue. Thanks for the correction Matt!

I've already updated to 9.14 and it was only after that I was informed my ADS-B data was not reporting correctly.

Thanks for letting me know in Post #6 about the new field in the Transponder section! I will go to the hangar tomorrow to click the "1e-7" selection.
 
GTX SIL Level

I've already updated to 9.14 and it was only after that I was informed my ADS-B data was not reporting correctly.

Thanks for letting me know in Post #6 about the new field in the Transponder section! I will go to the hangar tomorrow to click the "1e-7" selection.

The update to v9.14 should resolve any configuration problems, and SIL should automatically be set to the proper level (1e-7). Please let us know if continue to experience any issues related to this and we can work through it with you.

Thanks,

Justin
 
The update to v9.14 should resolve any configuration problems, and SIL should automatically be set to the proper level (1e-7). Please let us know if continue to experience any issues related to this and we can work through it with you.

Thanks,

Justin

I did get to the hangar today. The new field was set to "VFR GPS" or something similar. I made the change to IFR GPS 1e-7 and saved/rebooted. Unfortunately wind speeds today were uncomfortable for Light Sport flight so I will test the update as soon as weather permits.
 
Please let us know if continue to experience any issues related to this and we can work through it with you.

Had the chance to get in the air this morning. I ran a PAPR report and ADS-B Out is reporting correctly again.

Thank you for your help and guidance!

Jayson
 
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