The GTX 345 seems to be a pretty amazing little box. I now have a copy of the installation manual and am reviewing it. So far I understand it’s virtually the same size as a King KT76A Mode C unit and has both Mode S and UAT based ADS-B, in and out, an optional on board GPS receiver, and can Bluetooth GPS position, traffic and weather to a portable device or tablet. The traffic data is air-to-air from ADS-B outputting aircraft and also when available from ground stations that send all transponding aircraft, not just ADS-B equipped aircraft. About USD $5800 IIRC with all those bells and whistles, so not cheap.
Unfortunately and following up on my earlier post, it’s going to take a field approval if I want to put one in my plane because the type is not on the approved model list (AML) for hassle free installation with the Garmin STC. I have until 2020 to figure it out and I’m also curious if and when competitors may come out with a similarly self contained and Bluetooth outputting unit.
The ADS-B In receiver is dual frequency, both 1090ES and UAT.
Normally the IM has some specimen text to use for the Field Approval, with a Form 337.
The STC IM for the GTX345 doesn’t exist yet – a few weeks to go.
The TSO IM for the GTX345 does exist 
Let’s not forget the totally stupid EASA positron of requiring an STC for ADS-B equipment.
Currently it’s not just EASA that requires an STC for ADS-B OUT- the same requirement exists in the U.S. and Australia. Some talk of potential changes to Minor modifications, but nothing is yet confirmed.
FAA allows for field approvals – not all certified aircraft can or will be covered by generic STCs. Given the limitations of STC approved model lists and the huge number of N-registered, certified, US based aircraft that will need ADS-B, it appears to me the current trajectory is for a whole lot of FAA field approvals. Since that volume of field approvals may not be practical, because FSDOs don’t want extra (or any) work, and because the FAA will over time gain confidence in ADS-B field installations, I can well imagine that FAA will eventually make it a logbook entry situation. My plan is to wait and see. Plenty of time until 2020.
What is the work involved for an aircraft to be on an AML STC? Is it much more than adding a line to the list?
Currently it’s not just EASA that requires an STC for ADS-B OUT- the same requirement exists in the U.S. and Australia. Some talk of potential changes to Minor modifications, but nothing is yet confirmed.
If they want to get widespread adoption they will have to make it Minor, eventually. We had the same here in Europe, when one needed a Major mod for any GPS installation capable of flying GPS approaches. And I mean any GPS approach.
I recall a presentation by a UK CAA “top” guy who was quite disgusted when I told him the French allow GPS approaches flown with any BRNAV compliant GPS installation In the same meeting, he said the CAA asked the FAA whether they ever did any studies on the reliability of GPS approaches and the FAA replied they had not. Evidently, the FAA contact was some toilet cleaner because a load of studies were done, as I found out rapidly when asking around US sites afterwards. But that didn’t stop the CAA paying some firm of consultants (probably ex CAA people 
) to work out some probabilities, which came out to something like 99.99854%. You just have to respect pseudo science sometimes; it has it’s place in society… but even now, almost 10 years later, they say you cannot have LPV with a nonstandard GS.
Eventually it was realised GPS approaches would be dead in the water, so the policy was changed. But it set the whole scene back about 5 years. This is how Europe works. Vested interests all the way until somebody realises they have killed the goose.
ADS-B will be dead unless it is a straight installation. Currently almost nobody in light GA in Europe is radiating it and it will stay that way.
Cobalt wrote:
What is the work involved for an aircraft to be on an AML STC? Is it much more than adding a line to the list?
Apparently more work than Garmin is willing to do for me, based on my question to them yesterday. They advised me to pursue a field approval.
I’m going to fit a GTX345 as soon as it’s approved in EASA-land. Easiest way to get ADS-B in and out.
