So the whole -250 vs -2020 thing is nuanced. A couple of years ago, because of the way the SIL=0 (-250 at the time) ADS-B Out reports interact with other traffic, FAA decided to consider SIL=0 aircraft the same as completely unequipped. So -250 equipped aircraft stopped receiving aggregated traffic from the ADS-B ground stations. We looked, determined that we meet the requirements to be a SIL=1 device, and asked if those wake up the system and get sent traffic back. The FAA confirmed that they would. I don't think that they ever promised that it would work until -2020, but I don't think we anticipated that they'd change anything after that. What is true is that you don't have to have a compliant Out solution (which would require a -2020 or other certified GPS position source) until 2020. That isn't the same as saying "the -250 will work until -2020". Now that the FAA is ramping up automated compliance testing, they've determined that ANY non-compliant emitter will not receive traffic back. We can't speak for them, but I suspect that the approach is to tighten things up as 2020 approaches. If we weren't only year or so from the actual mandate deadline, we'd probably look into whether or not there were other solutions (like we did years ago with the SIL=1 solution) that would preserve traffic, but at this point, with the mandate around the corner, and the -2020 being perhaps the most affordable way to update to be compliant, we think that our efforts aren't best spent trying to have the FAA issue a temporary reprieve here.