On Monday, August 3, 2015 at 12:39:51 PM UTC-7, Darryl Ramm wrote:
On Monday, August 3, 2015 at 11:00:01 AM UTC-7, Steve Leonard wrote:
On Monday, August 3, 2015 at 11:06:16 AM UTC-5, Mark Palmer wrote:
Out of curiosity, is there any equipment currently on the market that meets the TABS requirement?

Mark

Nothing that I am aware of. Requirements were just finalized in October of last year. I would need to dig back through some discussions I have have with others, but think of TABS as pretty much a Mode S transponder with the GPS input for "extended squitter" or 1090ES out. There are some other differences, but that is probably the closest description you will find of "TABS in 100 words or less".

Steve

There are two parts of the TABS specification, Class A devices which is a slightly stripped down Mode-S transponder with 1090ES Out and Class B devices which are a GPS Source to provide the input to Class A TABS devices. Full Mode S/1090ES Out transponders can also meet the requirement of TABS devices, and so opens up the possibility of using a TABS Class B GPS to drive those for TABS use.... but for example that (currently at least) will not be usable to meet any of the 2020 ADS-B Out carriage mandate for (powered aircraft). And since TABS only exists as a TSO for devices, there are TABS installation, carriage or use regulations *at all*... so anything beyond what the boxes technical specs are is totally unclear, and what the SSA should be workign on, what ends up happening with TABS could be useful or could be horrifically bad for gliding and other aviation segments.

I expect/hope that being able to eventually meet FAA 2020 ADS-B Out carriage mandates for GA aircraft using (hopefully) lower-cost TABS Class B GPS sources is something that AOPA and EAA really want to see happen.

There seems to be widespread confusion about TABS Class B GPS sources, while technical aspects of the TSO was written to make it possible to use some consumer GPS chipsets, that GPS product still needs to be manufactured by a TABS TSO holder, and has to meet specific complex tests (using a constellation simulator as described in the TSO spec). And in order to actually ship a "TSO'ed product" that manufacturer has to be licensed and working within the the regulated avionics manufacturing process in their country/regulatory area. So at least based on interpreting the current TSO, and understanding some of the concerns the FAA has about GPS technology, folks won't be connecting any old consumer GPS source to a TABS box or a Mode S Transponder.