What ADS-B Out and In system are you talking about? Flying where. If you are looking at a GA style ADS-B In system I would certainly be looking at a dual-link receiver for lots of reasons.

Lots of this has been discussed on r.a.s. in the past

ADS-B In does not just "see" transponders. But if you and the transponder equipped aircraft are within suitable SSR / TIS-B ground based station coverage and you have properly configured ADS-B Out and ADS-B In then your ADS-B In system should see that transponder equipped target via the ground based TIS-B service. For many glider traffic scenarios, e.g. flying in mountains, running ridges, flying out of remote gliderports/airports, TIS-B may not be nearly effective as being able to receive direct position information from another aircraft (via ADS-B direct or FLARM). And the moment you actually do get close to another glider like in a thermal, any ADS-B traffic system (besides PowerFLARM) is going to be uselessly annoying. Yes I know that scenario does not interest you.

TIS-B only provides coverage in a hockey puck around your ADS-B out equipped aircraft, it's not going to be as useful as ADS-B direct reception between gliders for say buddy flying/tracking. That may not interest you either, I know that both interest some folks and horrifies some contest traditionalists.

PowerFLARM users will get non-directional PCAS alerts from your presence as long as your transponder is being interrogated by SSR or TCAS/TCAD. That may happen even though you are not getting any warning of them when outside TIS-B coverage. If you have 1090ES Out you

If (big if) the USA gliding community, with some err help from the FAA, ends up adopting TABS technology in future, that is all 1090ES Out based technology. All directly compatible with 1090ES In capability in PowerFLARM. And may be a path to give you a lower cost 1090ES out option in your Stemme (hopefully leveraging your currently installed TT-22).

An investing exercise is to look at the local airports you fly out of, find out what the ADS-B ground station coverage (including down to pattern altitude) is like, and ask around about what ADS-B Out and In systems aircraft owners there are equipping with and try to answer questions like what collision avoidance help different ADS-B Out and ADS-B In technology will provide you. I have no idea what that would show for you, but it's one of the questions I'd be asking.



On Friday, May 20, 2016 at 9:49:55 AM UTC-7, Dan Marotta wrote:
Just goes to show that there's too much to know unless you're
employed in the industry as you appear to be.

Since I don't often fly with other gliders, I don't much care
about PowerFlarm.Â* I want to see and be seen by airlines and GA
aircraft.Â* I imagine that, if the PF equipped aircraft also have a
transponder, I'll see them too, with ADS-B In.Â* Am I wrong?





On 5/20/2016 10:44 AM, Darryl Ramm
wrote:



I'm not sure why you deciding to have UAT Out has anything to do with flying near Class B airspace. (the big technology thing there is just having a transponder at all for TCAS compatibility, so you are set).

But choice of ADS-B Out link does have everything to do with flying in areas with other gliders and painting on their PowerFLARM. You don't want to be visible to PowerFLARM 1090ES In?

If you already have a Trig TT-22 I expect you will find more affordable GPS options in future, or if TABS regulations happen then I hope TABS options using the TT-22. A transponder and separate UAT system and maybe separate GPS you have more avionics to power.



On Friday, May 20, 2016 at 8:10:53 AM UTC-7, Dan Marotta wrote:


Agreed.

I'm currently researching ADS-B Out options for my Stemme.Â* And
though I have a Trig TT22 transponder already installed, the
1090ES options seem quite expensive.Â* I'm starting to lean towards
978UAS as my solution since I don't intend to fly above FL180 or
anywhere near Class B airspace.Â* Still much digging to do and even
after finding what works for me, I'll still keep my head on a
swivel (as I learned in the AF).

Dan





On 5/19/2016 9:57 PM, Ramy wrote:



Thanks Dan
I also agree with most of it, which basically says we should make our won decision what is acceptable risk. Totally agree with this part.
But after thousands of cross country hours I concluded that no matter how hard we try, we can't trust our eyes to detect a collision risk on time when cruising, especially not gliders who are practically invisible. Sure we see all kind of traffic, but not the ones on collision curse especially if not on our 12 and not maneuvering. And it's not just me, it's everyone with human eyes. There are many eye opening tests that confirm this. While see and avoid certainly works while thermaling, formation flying and in traffic pattern, it does not work when cruising. The reason why we don't have more midairs are not thanks to see and avoid but thanks to the big sky theory. I read somewhere that if we all flew blind folded, the collision rate would have not increased by much. I believe this is true. That's why we need as much help as we can get in this department, and if it is going to be mandated, I don't see a problem with that, as long as it is effordable.

Ramy





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Dan, 5J






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Dan, 5J