XPDR ADS-B UAT Error Code

[AaronF]

Hi Folks,

Occasionally 2 separate Xponder Alerts pop up on my Nxi PFD, sometimes on the ground, other times in flight.
My DA40NG is fitted with TAS 605 + GTX345R.



Do any of you guys flying in Europe get similar PFD alerts?

Thank you!

[Rich]

I didn't know 978 UAT was even used in Europe. If this is just occasional loss of signal, I wouldn't be surprised. In the US it comes from a number of ground stations and can be blocked by intervening mountainous terrain, especially down low to the surface.

[CFIDave]

Do you have a GTX345R or GTX335R installed in your DA40NG?

Unless you fly in the US where ADS-B IN services are provided, I would imagine you have only a GTX335R. If so, it looks like your G1000 NXi software was mis-configured to include a GTX345R, including a "failed" non-existent Ethernet connection between the transponder and your panel.

Time to visit a Garmin avionics shop to fix this.

[greg]

Unless you fly in the US where ADS-B IN services are provided, I would imagine you have only a GTX335R.

1090 ADS-B in capability doesn't rely on ground support, so isn't restricted to the US. The traffic information comes directly from other aircrafts' ADS-B out transmissions. So there's certainly good reason to install a GTX345R unit outside the USA. It's the display of weather and non-ADS-B traffic through the GTX 345R that requires the ground support.

But I have no idea why there would be a UAT error message on a non-US aircraft. (I don't know about Europe, but here it's illegal to enable UAT at all - the spectrum is licenced to someone else.)

[CFIDave]

Unless you fly in the US where ADS-B IN services are provided, I would imagine you have only a GTX335R.

1090 ADS-B in capability doesn't rely on ground support, so isn't restricted to the US.

But there aren't many GA aircraft in Europe equipped with ADS-B Out to trigger a direct traffic warning, and there are no ADS-B weather services there. That's the reason Diamond didn't make the GTX345R standard in its new aircraft, and why outside North America many G1000 NXi owners keep the standard GTX335R -- hence my question about GTX335R vs. GTX345R installed.

[Boatguy]

The OPs post says he had a 345 and that error msg is in the Pilot’s Guide. The FIS-B W’s can be disabled in the ADSB page per Pilots Guide pg 300.

As Dave suggests I think the UAT error will require reconfiguration of the 345 by an avionics shop.

[Rich]

It's a legitimate question to confirm whether it's a 335 or 345. If a 335, since such boxes have no UAT capability, what is the source of the message? A mis-configured panel?

Rationale for installing a 345 anyway in Europe:

1. There is a mandate for 1090 for faster (>250 kts) and heavier (12,500 lb) aircraft, effective June of this year.
2. Aircraft that operate across the Atlantic will already be equipped.
3. The price differential between the units is a minuscule fraction of the price of a new plane.