Flarm suppression of ADS-B out on Tow Planes

Bringing back this old thread.
So last year it seem that the ADS-B alarm suppression during tow was working well as I received only occasional short alarms.
However with most recent firmware and a new tow plane ADS-B installation I and others receiving constant alarm during the tow. Very distracting.
I don’t know if this is a regression in latest firmware or something wrong with the tow plane ADS-B.
I would like to know if others still experiencing ADS-B collision alarm during tow when towing behind ADS-B equipped tow plane.

Ramy

The PowerFLARM and ADS-B in the towplane have to have the same ICAO IDs (likely already done).

Without a PowerFLARM in the towplane, the glider PowerFLARM will see it as an ordinary power plane and can get worried.

Perhaps enrolling the towplane ICAO ID in FlarmNet will help the display logic. Won't hurt to try.

Hi Ramy

We're not aware of any regression. What firmware version are you using?

Sounds like the tow plane configuration is not consistent, either for the FLARM or the ADS-B transmitter. But that's me speculating.

Can you please send (IGC) log files to ?

Thanks
- Urban

Hi Urban,

I am using latest firmware 6.82.
Our tow plane has only ADS-B out, not flarm.
What configuration error in the tow plane could cause such issue?
I also exchanged emails with Daniel and will provide IGC file as soon as I get to my glider most likely next weekend.
Meanwhile I was hoping to hear from others if they still noticing false alarms during tow now that more and more tow planes in the US are equipped with ADS-B out.
I assume from the lack of response that folks no longer experiencing issues, or the season didn’t start yet for them to tell. Maybe the folks at Seminole can tell as their tow plane should be equipped with ADS-B out giving that they are in the Mode C veil.

Ramy

I am wondering if it would help to enroll the towplane ICAO ID in FlarmNet.

Of course the FlarmNet database is carried in the various traffic displays and flight computers, NOT in the Core.

In fact this is exactly what we did. I added the tow plane to flarmnet so we can easily recognize it. It works. I first suspected that maybe this caused the false alarm but then recalled that the powerflarm don’t know anything about the flarmnet database as the flarmnet is only used by the display, and as such could not impact the alarm suppression.

Ramy

Hi Ramy

Can't think of anything that's wrong here, 6.82 should suppress all ADS-B targets in the "right" relative position indicating a tow train. We'll have a look at the logs to figure it out.

As you mentioned correctly, FLARMNet does not influence alarming.

- Urban