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

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).

On Friday, December 18, 2015 at 11:23:25 AM UTC-8, Darryl Ramm wrote:
On Thursday, December 17, 2015 at 9:49:30 PM UTC-8, Mike Schumann wrote:

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).

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.

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).

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...tegory_popular

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

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

On Saturday, December 19, 2015 at 8:12:21 PM UTC-8, Bill T wrote:
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

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.

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.