Portable TABS coming to the USA?

On Wednesday, 20 November 2019 17:12:46 UTC, Darryl Ramm wrote:

Oh dear God I went and read CAA CAP 1391, that UK standard this uAvionix box implements. Now I want to stick a sharpened spoon up my nose and remove any memory of this insanity from my brain.

Yep none of the FAA TSO-C199/TABS TCAS-compatibility features seem to be in that spec. (remember TSO-C199 was largely driven by that Minden midair.... where getting compatibility with TCAS II in the Hawker 800 was a likely requirement). So an airliner with TCAS II... looks like it'll fly right into a GA aircraft fitted with a CAP 1391 device with no TCAS RA. How does the UK CAA expect this to work? That ATC alone will keep traffic separated? In the UK where they mix up jet airliners flying into regional airports? This all seems a bad technology choice to me (spend more money and do TSO-C199/TABS and get TCAS compatibility, allow volume worldwide to lower prices--instead now we have very different fractured standards).

And as intended by DO-260B (1090ES standard) these CAP 1391 devices transmit "1090ES Out" but transmit it as DF=18 (downlink format) messages (not that standard DF=17 messages) intended to be used by devices which are not Mode-S transponders... DF=17 is used in the USA by ADS-R and TIS-B messages (those ground towers doing the ADS-R and TIS-B transmitting are not transponders). Now I'm curious if PowerFLARM in the UK will see those DF-18 targets from these devices...

You are mistaken. The vast majority of UK jet traffic is in Class D or A, most VFR GA is in Class G. Any GA in Class D will almost certainly be transponder equipped.

CAP 1391 is designed to encourage cheap ADS-B in & out (with SIL 1) for VFR GA in Class G. Most glider pilots use Flarm. SkyEcho is popular with power pilots as a GPS & traffic awareness source for navigation software.