If it could be made to work, it would mitigate the two safety concerns @Blaufranky raised:

- The need to go 'heads-down' in order to manually un-ignore alerts following glider release, and
- The distracting nature of the nuisance alerts of an otherwise known threat.

As an ex-tuggy I can fully see Blaufranky's concerns.

Sounds perfect Tim!

Thinking about it, could be useful for formation flying too.

Dear all,

thank you for following up on this topic and the useful comments.

I have tested the existing "silencing" option to silence the glider that is being towed ... but this is really only a work-around, no solution.

In our tow aircraft we have an original FLARM unit ... and this FLARM is not warning about the glider that is in tow ... so there is a solution and example.

A tow-rope is less than 100m long ... a silencing range of e.g. 200m BEHIND should avoid being warned of the glider in tow.

And no other aircraft appears all of sudden within this 200m BEHIND box ... they come from more behind and over a longer time and will generate a useful warning. If they would generate their first warning just 200m behind, then the warning will not help anyhow.

Other example of useful automatic silencing: SkyDemon silences all aircraft on ground. This is a newer and very useful feature.

As said before: thank you for the very useful combination of SkyDemon and SkyEcho II. I love it. This discussion from my end has the only purpose of possibly improving an already very good product.

I am using SkyDemon with SkyEcho II, FLARM-license and iPhone as a traffic screen and I could not be happier with this setup. Works like a charm. Thank you very much.

There is only one issue that I like to report for consideration:

I am flying the tow-aircraft in a glider club and with SkyEcho II + FLARM I get a much better overview on where all these gliders are.

But the glider behind the tow aircraft is generating multiple traffic warnings like "glider behind, following, same level".

I do not want to silence these warnings, because the glider will soon be released and becomes a potential thread.

Is there a work around for this issue, that I have not found so far.

Or can it be considered not to warn, if a target is following constantly on "almost same distance and same level" or from ground onwards.

Or more in general: an aircraft behind the own aircraft should not be a potential thread unless it gets into the half-sphere from approximately 90° ... 150° right to left or has much higher speed so that it obviously caches up.

Thank you again and very best regards

Frank

Dear SkyDemon,

I wanted to come back to this subject after more testing.

First of all, I love my SkyDemon and my SkyEcho and I am more than happy that I invested into this combination. SkyDemon has done a great job to integrate the two systems.

But when using SkyDemon + SkyEcho + Flarm during glider towing (or more general, in an area with high Flarm traffic), the development should go some more steps.

Yesterday I made about 30 tow-flights on an airfield with a lot of Flarm traffic.

The tug-aircraft is equipped with its own Flarm traffic monitor and I added my SkyDemon + SkyEcho for three reasons:

a) much better traffic screen on the iPhone.

b) ADS-B-In 

c) verbal traffic warning

During all the flights the Flarm traffic monitor did not issue a single warning ... simply because no other plane came in front of me.

But the SkyDemon verbal traffic warning was TALKING ALL THE TIME:

1.) "Warning: Glider behind, same level" - yes known when you tow, why bother, its behind ... and why do you repeat every 20 sec.?

2.) "Warning: Glider behind, overtaking 10 km / h" - really, how does the glider do that and how does SkyDemon generate such an exact speed calculation ?

3.) "Warning: glider ahead, 100 ft below" - yes ok, but it is on the ground, in the hangar and not moving.

4.) "Warning: glider, 400 ft below, same heading" - yes, I see it on the ground, they are pulling it back to the departure point with a car.

I repeat - Flarm was silent all the time, no single warning. 

I was really surprise to experience such a major difference in behaviour.

I accept that towing gliders might not be the number one use-case for SkyDemon.

SkyDemon is ahead of competition when it comes to Flarm integration into VFR Navigation software.

But Flarm by definition brings more glider-specific issues with itself, like tug-aircraft, like many stations on the ground close to each other, that want to be adressed.

Obviously Flarm has solved most of these issues and it would be very helpful if Skydemon solves some of the above topic over the time.

Thank you again

F.

P.S. I tried the silencing button as discussed last time, but most of the flight have a duration of 5 min. ... and when the tug lands, the next gliders waits.  There is simply no time to select / deselect certain gliders for silencing ... and all / many of them are named "Flarm" ... you simply don't know, which one you want to silence when they sit on the ground close to each other.

Unfortunately at the moment, as you've identified, SkyDemon is not optimised for your specific mode of flying (glider towing). Our collision avoidance algorithms are based on TCAS, tuned for light general aviation and are appropriate for the vast majority of people using our software. FLARM's algorithms are specifically tuned for glider operations and are almost certainly more appropriate for your usage.

Because glider towing is a niche usage for us, I cannot make any promises about whether we will ever implement features to detect towing (or formation) circumstances and suppress information about that traffic, sorry.