Garmin GPS 20A with Trig TT22 in Experimental Glider - OK?

[Paul Remde]

Hi,

I'm gaining knowledge in ADS-B over the years. But I can't say I'm an
expert. I could use some feedback from some of the extremely knowledgeable
people that monitor this group.

I sell Trig TT22 transponders - which are FAA approved for ADS-B when used
with an approved GPS source. But currently approved GPS units are $3500+.
I have been hoping that a much lower cost GPS unit "designed to meet the
requirements..." would become available in the future - making it possible
to have FAA approved ADS-B out that meets the requirements for 2020.

This week a customer pointed out a solution - I think. It is the Garmin GPS
20A. It sells for $845. That is still a lot of money for a WAAS GPS, but
it is a lot better than $3500. I believe the antenna is extra.
https://buy.garmin.com/en-US/US/in-the-air/sport-aviation/gps-20a/prod525504.html

The web site says that it is approved for ADS-B out in LSAs. It is not
clear to me whether it would be legal to use it with a TT22 in an
experimental, or non-experimental sailplane.

I believe that ADS-B will make our flying much more safe. I am angry that
the FAA requires $3500+ GPS units at this time. They are reducing safety.

I'm not trying to push ADS-B down the throats of anyone. I am just trying
to fill a need. Many gliders already have TT22 units and might consider
adding an $845 GPS, but not a $3500+ GPS unit.

Also, it is my understanding that "field approvals" are required when
installing ADS-B out systems in certificated aircraft. Would there be a lot
of expensive paperwork necessary to get FAA approval for a system that
includes a TT22 and Garmin GPS 20A?

Any thoughts?

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

[Andrzej Kobus]

Please read the FAA ADS-B installation guidance.

https://www.faa.gov/nextgen/ga/media/AEA-ADS-B%20Installation.pdf

[Jonathan St. Cloud]

Dynon offers $590 ADS-B GPS source

[Jonathan St. Cloud]

Too bad the GPS engine in a Flarm cannot be used for ADS-B coupled with the transponder with ADS-B capability.

[Paul Remde]

Hi Jonathan,

The Dynon offering looks interesting, but their web site states that it can
only be used with their systems.

"Can the SV-GPS-2020 be used with non Dynon transponders / ADS-B Out
devices?
No other ADS-B Out devices are known to currently support the SV-GPS-2020's
format. Dynon Avionics currently only supports SkyView and AF-5000
installations. The SV-GPS-2020 transmits RS-232 NMEA output (115,200 baud)
with additional integrity information."

Paul Remde
____________________________

"Jonathan St. Cloud" wrote in message
news:d355a41f-b1d3-4eb7...@googlegroups.com...

[Stephen Damon]

The Freeflight system is just a repackaged Trig 22 transponder. There is a ranger 1201 on Vansairforce for $1200. Some EAA folks have said that the Dynon Skyview has trig T22 in it.

[Eric Greenwell]

I have a Skyview system in my Phoenix LSA, and it does use custom Trig
T22 (or T21 - buyers choice). Skyview is for Experimental or LSA
aircraft, not certified; also, no glider pilot wants a Skyview system in
it - big physicall, big expense, and big power usage for little advantage.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"

https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/Guide-to-transponders-in-sailplanes-2014A.pdf
uy

[Andrew Ainslie]

I just wanted to give Paul a shout out for the extra research that he did on my behalf on this topic. It seems that there is no reasonable solution yet for us. That Garmin box is too expensive as they fail to point out that you also need to buy a $300+ antenna, which is just ridiculous. I emailed Trig and they rather coyly suggested that they would have a non TSO'd gps for use with the TT22 in the not too distant future. I'm going to wait it out a little longer. So unbelievably stupid that the FAA thinks that roughly knowing where a plane is ("roughly" being within about 10 feet most of the time) is inferior to having no freaking idea whatsoever. Utterly idiotic. Flying out of Harris Hill is ridiculously frustrating s we continually see power planes on autopilot or with pilots too confused on their instruments come way too close. I really wish I could upgrade my TT22 to ADSB out at a reasonable cost.

[Jonathan St. Cloud]

Why is it that the GPS from Flarm unit cannot be used? That seems perfect as we would get more Flarms in gliders and obviously they are accurate.

[Charlie M. (UH & 002 owner/pilot)]

On Thursday, December 17, 2015 at 11:23:00 AM UTC-5, Jonathan St. Cloud wrote:
> Why is it that the GPS from Flarm unit cannot be used? That seems perfect as we would get more Flarms in gliders and obviously they are accurate.
>
>

I believe because the GPS is not "TSO'd", meaning nobody has spent a ton of money getting it approved.
It may be even better (in performance & features) than an approved unit, it just does not have "the little stamp" that is a FAA blessing.

Along the lines of, "Speed is money, how fast do you want to go?", the FAA version is, "Legal is money, how legal do you want to be?".

I know there is a voltage regulator for our Super Cub that comes from a ~50's vintage Chevy for ~$40, the "FAA approved part" is a few hundred.
But it has the "little stamp".

[Jonathan St. Cloud]

But on an experimental glider, can't one have a non-TSO'd gps engine for a transponder that has ADS-B out? Isn't that what Trig is developing? Why have yet another power drain and another GPS when the modern glider already has one to three GPS's?

[Charlie M. (UH & 002 owner/pilot)]

My limited understanding is...... "Experimental" means anything goes, just don't try to sue anyone.
Most sailplanes today are certified, thus need TSO'd equipment (meaning, legal for your country)

I'm not well versed on some of this, it's the Internet (thus it may be true), YMMV (Your Mileage May Vary).

[Andrew Ainslie]

Apparently it can't just be any non TSO'ed GPS to be fully compliant. A few months ago the FAA opened up a new category whereby "equivalent" units could be used in Experimental, and this device of Garmin's is the first to fit this new niche. Hopefully others are following, including Trig. But agreed, it's ridiculous that we can't just use on of the other GPS's floating around our cockpits to give the TT22 the required information. Anything WAAS (hell, actually anything at all) is way better than either radar or nothing at all. Part of the frustration is that without ADS-B we get no input. It would be so nice to know where the power guys with mode C are relative to us. The FAA definitely needs someone like JC to explain why their strategy of "forcing" us to get ADS-B out in order to get in is deeply flawed, and the requirements to either spend over $3000 or be blind is equally dumb... But that ain't going to happen. In the interim, I'm going to keep hoping that a reasonable solution shows up.

There is an intermediate solution whereby you can hook up a non compliant unit but if you properly declare the signal, I don't think you get ADSB in but I don't recall the exact details. I'd prefer full compliance but I think it might be time to play with that option over winter.

The next problem, of course, is to get a transponder shop to help you get anything done. They are very leery of helping with experimental planes and non TSO'd options. My local guy just told me that he'd no longer do my transponder certification, even though the TT22 is a TSO'd unit and he installed it a year ago - he claims the FAA does not allow him to work on experimental. Sounds like baloney but not much I can do about it if he doesn't want to do the work.

[Charlie M. (UH & 002 owner/pilot)]

(In the US, 'Your tax dollars at work', or not, your choice....).

I'm only commenting on my limited knowledge of how some of this works, I also agree some of it "sorta sucks"...... but what do I know....

[Bob Gibbons]

On Thu, 17 Dec 2015 09:46:39 -0800 (PST), Andrew Ainslie
<asai...@gmail.com> wrote:
> much text deleted....

> The FAA definitely needs someone like JC to explain why their strategy of "forcing"
> us to get ADS-B out in order to get in is deeply flawed, and the requirements to either
> spend over $3000 or be blind is equally dumb...
>

If you have a normal PowerFlarm unit you have a full function ADS-B IN
unit. Any aircraft transmitting ADS-B OUT will show up on the Flarm
display.

From https://flarm.com/products/powerflarm/powerflarm-core/
PowerFLARM Core comes in two variants, PURE and ADS-B. The ADS-B
variant has all the functionality of PURE, but with an additional SSR
(Transponder) and ADS-B receiver. In addition to FLARM equipped
aircraft, you will also be able to see transponder equipped aircraft.
Aircraft without ADS-B Out capability will be shown with approximate
range and altitude difference (Mode-C). Aircraft with ADS-B Out will
be shown identical to FLARM aircraft.

Bob

[Darryl Ramm]

Not strictly a completly clear statement. The PowerFLARM documentation should say "1090ES" instead of "ADS-B". They are writing in part for a European audience/bias where they don't have the UAT silliness to deal with. Pf the ADS-B soup in the USA... PowerFLARM only sees 1090ES Out equipped aircraft, does not see UAT Out and will not receive ADS-R or TIS-B services either.

[Stephen Damon]

There is a 2-33 in West Texas that has a Skyview!

[Mike Schumann]

Gliders are currently exempt from the 2020 ADS-B rules. As a result, you should be able to use a non-compliant GPS source with a Trig21 or Trig22, as long as the Trig is compatible with the GPS's datastream. Even though the GPS source is non-compliant, it will trigger the ADS-B ground stations so that you will get TIS-B and ADS-R transmissions.

This is what the Dynon Skyview systems do today. According to Dynon, this will continue to work after 2020 if you are flying in airspace where ADS-B is not required.

I expect that we will see affordable 2020 compliant GPS sources in the relatively near future. The Dynon units, which are suppose to start shipping by the end of this year, have set a pretty aggressive price point (under $600). While the Dynon module only works with the Skyview system, I was talking to an engineer at Trig a couple of months ago, who told me that they were planning to introduce an affordable compliant GPS source at a similar price point shortly after the Dynon units start shipping.

One thing that you should think about if you want to be fully 2020 compliant is that you buy a Trig21, NOT a Trig22 transponder. The Trig22, while it is ADS-B OUT compatible and will trigger the ADS-B ground stations, is NOT 2020 compliant.

[jfitch]

Other way around isn't it? Trig 22 has legal power, Trig 21 does not? What happened to all the noise around the FAA survey and a lower cost alternative (forget the name of it)? That is the place to push for Trig21 and Flarm GPS.

[Sarah]

Hi Paul,

Here is a post from a Garmin engineer about compatibility of the 20A with the Trig TT22.
http://www.vansairforce.com/community/showpost.php?p=1013960&postcount=5

Here is the list of certified GPS WAAS sources on Trig's web page currently:
http://www.trig-avionics.com/support/u-s-ads-b-stc-program/

Putting the two together, it seems likely the 20A is compatible with the Trig. However you would need Trig to say that is so.

The link to the FAA page in the Van's forum post explains what the FAA expects for experimental non-TSO'd GPS WAAS sources.

None of this applies to non-Experimental gliders. The 20A is not permitted, a TSO'd GPS source is required. Since gliders don't ever seem to make it onto "approved model lists" in transponder/ADS-B STCs, a field approval would be required.

That's my understanding at least. Any traffic in the area that knows better, please advise.

Sarah Anderson

[Richard Pfiffner]

On Thursday, December 17, 2015 at 9:49:30 PM UTC-8, Mike Schumann wrote:

Mike,

The TT21 is not 2020 compliant.

The TT22 is 2020 compliant

http://www.craggyaero.com/Trig/ADS-B Just Got Easy - Trig ADS-B STC


Richard
www.craggyaero.com

[Darryl Ramm]

On Thursday, December 17, 2015 at 9:49:30 PM UTC-8, Mike Schumann wrote:

> Gliders are currently exempt from the 2020 ADS-B rules. As a result, you should be able to use a non-compliant GPS source with a Trig21 or Trig22, as long as the Trig is compatible with the GPS's datastream. Even though the GPS source is non-compliant, it will trigger the ADS-B ground stations so that you will get TIS-B and ADS-R transmissions.

To be clear here if your glider is certified you cannot install any old GPS source. You needs to meet the FAA requirements which includes a TSO'ed IFR GPS source, discuss with your A&P/FSDO.

Unless you are a super-geek wanting to play with this stuff, just wait and see what happens with ADS-B and TABS carriage requirements for gliders.

The FAA is making it clear that non-compliant ADS-B out sources will not continue to receive ADS-B ground services in the future even if they do now. January 2016 I think is the cutoff threatened/promised by the FAA, if SIL/SDA=0 from your GPS source you will not be provided ADS-R and TIS-B ground services. And in the meantime the friendly FAA may drop you a snail mail to remind you that your aircraft is flying around with a non-complaint ADS-B Out. Having an ADS-B Out system that triggers ADS-B ground based services (ADS-R and TIS-B) won't help you anyhow if your ADS-B receiver is a PowerFLARM which receives 1090ES direct and is not capable of receiving ADS-R or TIS-B data).

>
> This is what the Dynon Skyview systems do today. According to Dynon, this will continue to work after 2020 if you are flying in airspace where ADS-B is not required.
>
> I expect that we will see affordable 2020 compliant GPS sources in the relatively near future. The Dynon units, which are suppose to start shipping by the end of this year, have set a pretty aggressive price point (under $600). While the Dynon module only works with the Skyview system, I was talking to an engineer at Trig a couple of months ago, who told me that they were planning to introduce an affordable compliant GPS source at a similar price point shortly after the Dynon units start shipping.
>
> One thing that you should think about if you want to be fully 2020 compliant is that you buy a Trig21, NOT a Trig22 transponder. The Trig22, while it is ADS-B OUT compatible and will trigger the ADS-B ground stations, is NOT 2020 compliant.

Good advice, if buying a transponder now and wanting best ADS-B options/flexibility in future. But in the big picture again this may change if TABS carriage regulations happen (the TT-21 meets TABS power requirements even if it does not meet ADS-B out power requirements).

[Darryl Ramm]

OK thanks for the private emails :-) Doh I did not spot the (likely accidental) transposition in Mike's post. To be clear the lower-powered Trig TT-21 does *not* meet the ADS-B out requirements in the USA. You need a higher-powered Trig TT-22 (and certified IFR GPS source). But as I said, TABS devices have lower power requirements so if TABS is adopted a TT-21 should be usable as a TABS device (and that includes triggering all the ADS-B ground infrastructure base services). But since there are no TABS installation or carriage regulations yet we have no real idea about any of this actually happening.

[Darryl Ramm]

On Friday, December 18, 2015 at 11:56:18 AM UTC-8, Darryl Ramm wrote:

> OK thanks for the private emails :-) Doh I did not spot the (likely accidental) transposition in Mike's post. To be clear the lower-powered Trig TT-21 does *not* meet the ADS-B out requirements in the USA. You need a higher-powered Trig TT-22 (and certified IFR GPS source). But as I said, TABS devices have lower power requirements so if TABS is adopted a TT-21 should be usable as a TABS device (and that includes triggering all the ADS-B ground infrastructure base services). But since there are no TABS installation or carriage regulations yet we have no real idea about any of this actually happening.

OK and one more... since I see this come up occasionally. The 2020 Carriage ADS-B Out regulations that require a TT-22 (if you wanted to do any install in a certified glider or a complaint install in an experimental glider) and not a (lower power) TT-21 are completely separate from the old needing a higher power (Class 1) transponder over 15,000' regulation. The TT-21 unfortunately does not meet the ADS-B Out power requirements in the USA (a unique issue to the USA because of the reliance on widely space ADS-B ground stations), even below 15,000'.

Bottom line if buying a transponder today in the USA, just get the Trig TT-22. A fine piece of kit. If you don't need a new transponder today (like you have a working Mode C transponder already, just WAIT... and see what happens with FAA regulations and new products entering the market).

[son_of_flubber]

I've no personal knowledge of the following kickstarter. It could be totally legit, self-delusional vaporware, or a deliberate money-extraction-scheme. It promises some subset of ADS functionality at a very low price point and may therefore be of interest.

https://www.kickstarter.com/projects/bad-elf/bad-elf-ads-b-affordable-weather-and-traffic-recei?ref=category_popular

I'd guess that you'd want to use it with an Iphone in a glider not an Ipad Mini.

[Darryl Ramm]

The ADS-B receiver is really not the issue...

[Darryl Ramm]

On Friday, December 18, 2015 at 5:26:49 PM UTC-8, Darryl Ramm wrote:
> The ADS-B receiver is really not the issue...

(repost with more details, sorry the earlier one escaped)

And just becasue I can't resist a good rant and chance to kick a bad idea... This BadElf ADS-B is a UAT In only receiver. It cannot directly "see" 1009ES Out (or TABS equipped... if TABS takes off in the USA) equipped aircraft.

OK sure, if your aircraft is equipped with this BadElf receiver and also the correct/compliant ADS-B Out that is correctly configured to advertise you have a UAT receiver and you are in range of the FAA ground infrastructure then you should receive ADS-R services that allow this receiver to "see" 1090ES Out equipped aircraft. Oh wonderful stuff (he cries sarcastically...).

But to give them credit it has pretty good naming, as this BadElf product is indeed a bad idea, just fundamentally flawed. And Stupid Elf might be an even better name. There is no excuse for a USA based manufacturer to be developing an ADS-B receiver today that is not dual-band/link layer. It just makes no sense. And with any single link layer receiver the requirements to fully participate in the ADS-B services are likely too confusing/difficult for the market/many owners/pilots to undertsand and configure correctly (anybody want to tell me how they can change the capability code bits in their ADS-B Out system so it transmits the right magic so the FAA ground infrastructure knows you have a UAT receiver so it will provide ADS-R services to your aircraft?... ah no I thought not).

I hope, for saftey reasons, that this BadElf product just will not get crowd funded/will not sell well. If it does that may reflect more market confusion than them having a great product. Why would anybody buy it when there are better, and already relatively low-cost dual-link receivers already available from much larger/proven manufacturers. Including Apparero Stratus 2S (https://www.appareo.com/aviation/ads-b/stratus) and Garmin GDL-39 series (https://buy.garmin.com/en-US/US/in-the-air/avionics-safety/weather-solutions/gdl-39/prod93601.html). The GDL-39 starts at less than $600. Those products directly receive ADS-B from 1090ES Out *and* UAT Out equipped aircraft, without relying on ADS-R at all. They will work outside FAA ground station range, and importantly will work regardless of whether your own aircraft has ADS-B Out installed or not. (The Status 1S is UAT In only, the 2S I mentioned is a dual link-layer receiver).

---

And in gliders in the USA we have significant PowerFLARM adoption. PowerFLARM as deployed in the USA, where it has the 1090ES In option included, does receive 1090ES directly but not UAT. And PowerFLARM has a limitation that it is not compatible with ADS-R or TIS-B--so whether you have ADS-B Out in your glider or not does not change what your PowerFLARM shows you. If you have 1090ES Out other PowerFLARM can see your 1090ES Out signal, and hopefully at significant longer ranges than typical PowerFLARM to PowerFLARM. In an ideal world PowerFLARM's ADS-B In capability would also be dual-link, but it's a specialized device mostly for the glider market and its ancestry is from Europe, and UAT, ADS-R and TIS-B are USA only silliness. I suspect the complexity of building a custom system just for the USA glider market means that just will never happen. So there is a trade off of putting good enough ahead of perfect. At least PowerFLARM has PCAS support that helps warn of transponder equipped aircraft (if they are being interrogated etc.).. which will help with UAT Out equipped aircraft which also have transponders (most/nearly all will). And anyhow I'm suspecting there will be more 1090ES Out adoption than UAT Out across the whole USA aircraft fleet as we approach 2020, and if TABS is adopted for gliders and maybe other aircraft then that is even more 1090ES Out... which all works great for those with PowerFLARM. And hopefully glider owners/pilots/FBOs/Clubs etc. have enough sense by now to know that UAT Out only devices are not good choices for equipping gliders with, or other aircraft with, that mix frequently with gliders.

There is no way of just connecting/combining say a PowerFLARM and separate UAT or dual-link ADS-B receiver. That would take significant custom software development, for a likely market of a small number of glider owners/pilots in the USA who care enough to want both FLARM and dual-band ADS-B In capability. And just having two separate systems in the cockpit is likely far too much confusion/distraction, especially trying to think about/manually deduplicate threats showing up on both systems.

---

Did somebody recently suggest not over worrying about all this stuff and just waiting and seeing what happens? Including with possible TABS installation and use regulations and adoption in the USA? Ah yes I did, several times now :-)

[Bill T]

You no longer need to trigger ground stations to get TIS-B or FIS-B data on the UAT frequency.
I have a Raspberry Pi set up to receive UAT TIS-B and FIS-B data. Get great data with no "trigger".

BillT

[Darryl Ramm]

You never had to do anything to get FIS-B data. It is just broadcast.

If you are seeing TIS-B messages (and are you discriminating between UAT direct, ADS-R and TIS-B?) then you are likely seeing transmissions made for client aircraft. And in some busy areas that might mean near continuous coverage. There are no ADS-R messages just transmitted blind.

[Bill T]

I am receiving traffic data miles away from other aircraft. It is not triggered data meant for another aircraft. I have a Rasberry Pi set up to receive 978 UAT. Program is called STRATUX. The Pi rebroadcasts on wifi to my iPad and ForeFlight software.

FAA openly broadcasts TIS-B data on UAT, they opened it up this fall. From what I understand.

I was at 6500MSL over Searchlight NV and receiving traffic data in the Las Vegas Valley, 30 miles away. All I needed was line of sight to Black Mt., where the FAA ground station is located.

[Darryl Ramm]

On Saturday, December 19, 2015 at 9:38:51 PM UTC-8, Bill T wrote:
> I am receiving traffic data miles away from other aircraft. It is not triggered data meant for another aircraft. I have a Rasberry Pi set up to receive 978 UAT. Program is called STRATUX. The Pi rebroadcasts on wifi to my iPad and ForeFlight software.
>
> FAA openly broadcasts TIS-B data on UAT, they opened it up this fall. From what I understand.

Unfortunately it is next to next to impossible for a user with an ADS-B receiver to work out what is going on, what ground station is transmitting data what for which client(s) aircraft. You at best can tell if a message was ADS-B direct, ADS-R or TIS-B. But you very likely cannot often find details of a client aircraft. And you expect to see some UAT TIS-B and ADS-R data for other client aircraft.

I am not aware of the FAA just retransmitting all this data without a client. Do you have a link to them talkign about doing this? Organizations like AOPA have been asking for that for a while, and getting pushback AFAIK. Retransmitting TIS-B blind seems a horrific bandwidth waste I'm not sure it is doable. The only thing I am aware of is the FAA threatening to clamp down and become more restrictive starting in January 2016 tightening up the requirement that client aircraft have compliant ADS-B Out (well SIL>0 type GPS Specs). And there was a separate other change, all really covered here... https://www.faa.gov/nextgen/programs/adsb/media/TIS-B_service_change_summary_final_508_5-13-15-webV2.pdf -- but again not what you are describing, but I could see how the description of some of those changes is possible to cause confusion.

> I was at 6500MSL over Searchlight NV and receiving traffic data in the Las Vegas Valley, 30 miles away. All I needed was line of sight to Black Mt., where the FAA ground station is located.

Yes but that alone does not prove that there is blind re-transmission on UAT. All it likely means is there was one or more ADS-B or TIS-B UAT client aircraft somewhere near that traffic.

---

I am aware of Stratux, it is a very nice little project. I have not had time to play with it on my Pi yet.

[son_of_flubber]

On Saturday, December 19, 2015 at 6:56:16 PM UTC-5, Darryl Ramm wrote:
>There is no excuse for a USA based manufacturer to be developing an ADS-B receiver today that is not dual-band/link layer.

On Dec 17, 2015, Bad Elf announced what they're calling a dual band receiver. Does this address your dual band concerns?

https://www.kickstarter.com/projects/bad-elf/bad-elf-ads-b-affordable-weather-and-traffic-recei/posts/1447126

The price went up to $549 on the dual band model, but it now claims to include non-toy AHRS and a rudimentary Flight Data Recorder.

I'm not saying that this is legit, but it is interesting.

[Darryl Ramm]

Yes, indeed that solves the dual-link issue I have. Thanks for pointing
that out. But it kind of ruined the point of having a good long rant...
:-) But still I am far from impressed with their "oh we wanted to bring
a weather and AHRS product to market first"... uh bullshit they *were*
positioning it as a ADS-B traffic solution. Yes if you dug int the
details they warned that you needed ADS-B Out for ADS-R via the FAA
ground stations to give you 1090ES traffic data. But still there is no
excuse in my books for companies to screw around with new products that
are single link only receivers. Just a very very bad idea.

I do believe this is a legitimate attempt to do a crowdfunded device,
and BadElf has delivered nice GPS products before. I'm not questioning
them on any of that.

The question remains why not just buy a Garmin GDL39 or GLD39-3D (with
AHRS) or Status S2? Especially compared to funding a much riskier
kickstarter project for a somewhat cheaper ($549 vs. ~$900) me-too
product, vs. buying from very well established current vendors. We'll
see if they even get funded (they want $500k). Some even preliminary
specs like battery technology/life etc. seem to be not available.

It is a small sample size but effectively everybody I know who is flying
GA aircraft with portable ADS-B In is using a Stratus. I hope they are
all Stratus S2 (i.e. dual-link), but I'm not sure. That is largely
driven by the popularity of Foreflight software and their bundling with
Status.

OTOH personally much more interesting to me is the Rasberry Pi Stratux
mentioned here by Bill. (Note the dig at Appareo Stratus). That's a
great hacking platform for technical folks to play with and understand
ADS-B, the latest of several software defined radio projects (mostly for
1090ES In), but probably the most flexible. Not of any interest to me to
actually want folks to fly with... but interesting for folks who want to
play/understand ADS-B, set up ground receivers/trackers, etc.

[Bill T]

Thanks Darryl,
I'm still learning all the ins and outs of ADS-B. I remember the AOPA articles requesting the FAA open up the TIS broadcasts to all users.
I thought I had read something that it occurred this fall.

I see where FAA is considering after Jan 2016 to not rebroadcast traffic data on targets that are "non compliant" or NPE. This opens holes in the system after the FAA has allowed experimental aircraft to install equipment that meets specs, but not TSO'd. Will those targets not be retransmitted.

I realize I am flying within a busy Mode C Veil area and will have a lot of aircraft with valid ADS-B Out to trigger the TIS broadcast on UAT and 1090ES.
I did receive TIS data on UAT. From my location over Searchlight, NV. Any "expected" OUT aircraft would have been many thousands feet above and on the 1090ES frequency.

It is now 2016 ( for all practical purposes) and within 2-3 yrs we will need to install WAAS GPS and ADS-B out for the tow plane. Hopefully a reasonably priced single box unit. It would be interesting to see the results of the ANPRM study on transponder or ADSB requirement for gliders. We only have one club glider that has no electrical system with no radio/transponder capability. There are a few privately owned gliders with no transponder.

BillT