On Thursday, December 14, 2017 at 10:18:47 PM UTC-8, 2G wrote:
On Thursday, December 14, 2017 at 9:54:54 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 9:39:35 PM UTC-8, 2G wrote:
On Thursday, December 14, 2017 at 8:30:06 PM UTC-8, Darryl Ramm wrote:
On Thursday, December 14, 2017 at 7:20:02 PM UTC-8, jfitch wrote:

OK, so ADS-B information is transmitted in the blind?

Yep. Completely blind/automatic. That is what the A in ADS-B stands for.

Automatic Dependent Surveillance - Broadcast

Dependent meaning GNSS/GPS.

ADS-B Out broadcasts data messages several times per second completely autonomously, with some pseudorandom time dither to avoid correlated collisions. The mix is a bit complex with ID, status, position and velocity messages broadcast at different rates. Position and velocity are twice per second.

The ADS-B Out side of things make no response to any interrogation and cannot tell if anything is listening. 1090ES Out systems are in practice parts of Mode S transponders and so have a whole slew of other things they do including other automatic broadcasts (like acquisition squitters) and multiple different interrogation types and on high-end transponder even air-air data link for TCAS resolution coordination, etc.. Way more complex than legacy Mode A/C transponders.... and so complex you can see why the expectation back in the early days of ADS-B planning seemed to be that Mode S transponder costs were going to remain high, and why UAT might be a good idea.... well no because FPGAs and fast microcontrollers happened and turned transponder hardware into a software problem...

One more thing: if you get the TN72 you will also have to get a TSO'd antenna. So what, you say. Well the antenna costs as much as the TN72.

Tom

I would hope not, the thing is ugly as hell. If your glider is experimental there is no way I'd expect folks to install that, if certified ask your A&P IA what they want to see to sign off on a minor alteration to do a TABS install.

Hoping isn't a part of an inspection: if it isn't TSO'd how can it be signed off by an IA?

Hoping as in whoever does an install/sign off can work out the minimal work/correct thing to do for that particular install. That is their job.

There are lots of non-TSO equipment installed in certified gliders all the time. It is up to the A&P IA to determine if where needed the installation meets the performance requirements, and a TSO is one way of doing that. Trig also publish the key relevant performance spec of that antenna making it pretty easy to select alternate choices. But I am not an A&P IA and even if I was I am not the A&P IA doing the install in your particular glider.

I am not going to go down this rat hole further, if you want to do an install in a certified glider you need an A&P IA to sign off on that. If you want to move forward go and start that discussion with that person, if they are clear then book shop time, order the parts, and get go. If they get stuck or need contacts at Trig or the FAA I'm happy to help them, or SSA folks likely can as well (or better). One thing owners should avoid doing is contacting FSDO staff and asking them about ADS-B installs. Leave those discussions if needed at all to a trusted A&P IA who will actually be signing off on the install.