On Friday, January 22, 2016 at 1:01:28 PM UTC-8, ZP wrote:
I have one question getting back to Andy's question about FLARM GPS being fed into a transponder for ADS-B out usage (and Darryl, I apologize in advance if you already answered this).... But, "in a hypothetical world where cats and dogs sleep together, and the FAA decided to allow non-TSO'd GPSs to be used for VFR operations".... would there be anything technically missing that would prevent a FLARM GPS from being used as a GPS source for ADS-B out (e.g. protocol or some missing information in the data sentences that would result in the transponder from forwarding the GPS data?

Better change that to ..."in a hypothetical world where Hillary and Trump sleep together". I'm just trying to understand when someone says "Can't do it" whether that is based on technical or regulation reasons.

Covered before already on r.a.s. in many posts. Did you try searching?

The FAA is not going to allow any old GPS source for ADS-B. That should be absolutely frigging obvious. I've been over this many times. The *only* thing on the horizon is TSO-C199/TABS Class B GPS related regulations (if they happen). And TABS is *not* about you using any random GPS source. And I've explained just in this thread why it's unreasonable to expect FLARM to pursue TABS approval of their devices.

Is stuff missing in a NEMA source like FLARM? Yes stuff is missing. I kind of mentioned that in this very thread ("you can't do it over NMEA"... technically stuff is missing, but it's not even up to anybody to worry about for a certified aircraft, there you have to follow an approved install/pairing of GPS and ADS-B Out to obtain FSDO field approval).

So for actual installation using PowerFLARM GPS to drive ADS-B out.

A certified aircraft? Can't be done. You have no choice.

An experimental aircraft. You can do relatively speaking what you want... but will it work? That depends on how you define "work". It won't be seen by certified ADS-B In receivers in other aircraft (maybe a really bad thing), it won't (as of around now) trigger ADS-R or TIS-B ground services for your client aircraft (which may or may not matter at all to you). You have to know what you are doing when this is configured and get it wrong and the FAA may come looking for you. And you certainly can not use this to meet 2020 Carriage mandates, say when/if gliders lose the ADS-B Out carriage exemption.

Wanting to use PowerFLARM GPS to power ADS-B Out is the *wrong* thing to want. A complete waste of your and everybody else's and FLARMs time. What if anything changes moving forward is going to depend on TABS/TSO-C199C GPS devices. TSO-C199 *was* the FAA's response to folks wanting to use low-cost GPS sources--and it certainly does not just let you connect any GPS source up to ADS-B out, never was going to and nobody should have ever expected it to.

So yet again, just wait until we see what effect TABS carriage and installation regulations have in this area. If you have something specific now that makes any sense to worry about, like a specific transponder in a specific certified/experiential glider, a pressing need to get 1090ES Out and maybe willingness to spend some money. Cough up the actual details and question and you'll get help.

And get along to the SSA convention and listen to Dave Nadler's talk, he's much nicer than me.