Most well-equipped gliders in the US have PowerFLARM and at least a Mode-S transponder, such as a Trig TT22. An increasing proportion are equipping with ADS-B Out since the incremental cost is relatively low to add a GPS source. PowerFLARM is a 1090ES ADS-B In device and now decodes TIS-B (rebroadcast SSR targets) and ADS-R (rebroadcast UAT targets). Proper coverage for rebroadcast targets really requires ADS-B Out to establish the service "puck" around your aircraft for these rebroadcast targets from ADS-B ground infrastructure.

I am not aware of any gliders that have ADS-B Out but not FLARM. There may be a handful. There are many with FLARM but not ADS-B Out, though most of those have a transponder in my experience. I fly out west where transponders seem quite prevalent.

If you are flying a glider out of an area with other gliders in the vicinity it is likely that your biggest threat will be another glider. A FLARM-compatible collision avoidance device is required at all US National Championships and may be required by individual event organizers at regional contests or cross-country camps.

Andy Blackburn
9B

On Thursday, February 18, 2021 at 4:04:47 PM UTC-8, Jeff Bures wrote:
I gather that FLARM is much more popular outside of the USA. Are most well equipped sailplanes installing FLARM in the USA? What about other GA aircraft in the USA?

Is FLARM more common (or a necessity) at competitions in the USA? For club and casual cross-country soaring, it might be less prominent.

Having both FLARM in/out and ADS-B in/out is getting quite expensive. Would a budget minded sailplane in the USA get FLARM or ADS-B. Which has the most utility for situational awareness and safety in the USA?

What does FLARM offer that ADS-B does not? I'm assuming FLARM is faster and more accurate for gaggles. What's the relative refresh for FLARM and ADS-B data?

Yes, I know ADS-B out would open up some airspace that would normally be excluded, but I'm ignoring that factor for now.