On Saturday, January 31, 2015 at 5:58:39 AM UTC-8, Mike Schumann wrote:

This is going to be THE collision avoidance technology in the US.

Except for gliders, where it does't address the primary collision scenarios today and won't in the future.

ADS-B is architected to complement the ATC 5 mile/1000' separation philosophy. It's not good at close-in, dynamic collision warning the way PowerFlarm is. It doesn't doesn't do position prediction so it can't handle dropped packets the way PowerFlarm can (important close-in). In short it's not at all good for the glider-glider scenario and isn't adaptable to that scenario in the future.

Unless you have a transponder, carrying ADS-B won't light up TCAS carried on all large jets and most corporate jets and turboprops. TCAS will continue to be the primary (and perhaps only) collision warning system on these aircraft even after the 2020 carriage mandate. ADS-B fits in as traffic advisory and leaves TCAS to do collision avoidance.

If you want to stay clear of gliders get a PowerFlarm - that's the ONLY thing you can do today. IF the FAA pursues changes to allow lower cost GPS sources then if you are carrying a suitable Mode-S transponder (like the Trig TT22) you MIGHT be able to upgrade to an affordable full ADS-B 1090 ES In/Out system that would allow you to see/be seen by other ADS-B carrying traffic AND will provide TCAS collision warnings to all TCAS-equipped aircraft.

Stay away from all that ADS-B UAT stuff (unless you want to get a cheap UAT In device to get free aviation weather). Virtually no one is carrying ADS-B UAT Out today and there's no point in carrying a transponder AND an ADS-B UAT Out device when you can just add GPS to your Mode S transponder - which you need anyway for TCAS.

Cheap GPS sources would really finish out the collision avoidance technology picture for glider pilots by allowing glider pilots to install Mode S and PowerFlarm (Core, rather than Core Pure) today and upgrade to add ADS-B 1090 ES Out in the future.

9B