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Steve6443 wrote:

The transponder manufacturer must state that it will work with your particular GPS. Applicable to non-complex aircraft with a cruise speed less than 250 knots, or any ELA2 aircraft.

The reason for this statement is that the data elements needed for ADS-B Out to function are not supported by most legacy GPS systems. One can connect a GTX330 via a variety of means to a GNS430, but the ADS-B output will be immediately identifiable as not being connected to a compatible position source. Will it emit your position, sure. Will it emit the other elements required but never mentioned, not so much. ADS-B is much more than position. So the needed data elements have to be generated by the position source and the ADS-B Out system has to be coded to parse and accept the data elements from the position source. Legacy GPS systems such as the non WAAS GNS430 or KLN94 simply don’t provide all the data, so what is missing gets set to null or unknown. Could they provide that data, sure, but that will never happen for outdated and no longer supported avionics.

KUZA, United States

but the ADS-B output will be immediately identifiable as not being connected to a compatible position source

I am aware that in the US the FAA is checking these emissions and emailing owners whose ADS-B OUT is noncompliant, but I don’t think anybody in Europe is doing any monitoring whatsoever.

No European ATC can see ADS-B at all, AFAIK, except maybe in some limited local experiment. Some airfields have rigged up a laptop with a UHF receiver so they can see [some proportion of] local traffic, etc.

This is what enables EASA / the national CAAs to offer these concessions. Nobody cares what comes out of your transponder. ATC can see the standard Mode A/C/S and that’s it.

And there is a lot of promotion of “handheld” gadgets for EC (electronic conspicuity) – you can fill your boots e.g. here

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

No European ATC can see ADS-B at all, AFAIK

Certainly Stockholm ACC/TMC can see ADS-B.

ESKC (Uppsala/Sundbro), Sweden

Peter wrote:

I am aware that in the US the FAA is checking these emissions and emailing owners whose ADS-B OUT is noncompliant, but I don’t think anybody in Europe is doing any monitoring whatsoever.

Although true, I was not referring to FAA enforcement. A non compliant source is not going to emit geometric altitude, NACp, NACv, or NIC and in effect self declares the source is emitting an untrustworthy position. Any ATC use or certified traffic display use will take this into consideration. A portable device won’t care.

KUZA, United States
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