On Thursday, August 6, 2015 at 11:04:00 AM UTC-7, John Carlyle wrote:
Could someone please clarify - if a PowerFlarm is in Stealth mode, does that affect in any way the display of PCAS and ADS-B information? If it does, then to my mind there's no sense in using Stealth mode at all, ever.

Assuming Stealth only affects Flarm signal display, I think we need to consider why people would want Stealth used in contests. I think there are three basic types of pilots at contests - those that are hyper competitive, those that are trying to learn competition flying, and those that are just out for fun. It's clear that hyper competitive pilots will probably always want Stealth, so they don't give up any advantage. Those that are trying to learn competition flying will most likely not want Stealth used, so they get a better idea of what's going on around them in real time so as to learn/improve faster. Those out for fun would probably also not want Stealth, but most likely only for situational awareness.

It's the learning pilots that I think are causing the angst in this thread. Perhaps a good compromise would be to allow Stealth only in Regional contests, or perhaps only in Sports class?

-John, Q3

Stealth doesn't affect ADS-B or PCAS, but it does raise an interesting question.

As cheaper non-TSO'd GPS sources become available it is likely that some gliders will start equipping with ADS-B 1090ES Out (think Trig TT-series plus a Garmin GPS 20A, or equivalent). The future FAA position on ADS-B for gliders is TBD but there is an NPRM on transponders already on the table.

Ultimately, FAA action notwithstanding, you will see gliders equipped with ADS-B Out. These will offer ranges of many tens of miles, not the 3-5 miles offered by Flarm. All of that traffic information will be picked up by your PowerFLARM and go straight to your flight display and will include gliders as well as any power traffic equipped with ADS-B 1090ES. There's no stealth mode for ADS-B and ADS-B doesn't discriminate aircraft type. It does, I believe, transmit an ICAO code.

I'm guessing we don't want to be in the position of requiring pilots to turn off their ADS-B gear or banning its installation. You might be able to filter out glider ICAO codes using some sort of registration database like FlarmNet (not a current Flarm capability), but that starts to get pretty complicated and I'd bet the FAA would have something to say about it.

Not an immediate issue, but 5 years from now it could be very real.

John's points about preferences by pilot experience level are broadly consistent with my impressions talking with people - though there is a fair amount of variance. A poll question would put some real numbers against it.

9B