On Tuesday, December 1, 2015 at 10:15:10 AM UTC-8, Jim White wrote:
At 16:27 01 December 2015, Dan Marotta wrote:
I'd like to know how not identifying a glider by call sign or climb rate
(if I understand stealth mode) degrades safety. C'mon, people, you
sound like a bunch of evangelists.

It doesn't. As I understand from the documentation Stealth mode does not
change what is transmitted, only how the receiver displays it. Alarms are
fully functional at all times.

Not 100% correct (and it matters a bit for head-to-head, especially in multi-ship scenarios). The Flarm Configuration manual 1.02 dated August 4, 2015 states that even with alarms active you won't get a FlarmID or FlarmNet ID - so you won't be able to call the other glider(s) to make sure that they don't "zig" when you "zag". You won't have any information before 2 km unless they are headed more or less right at you - so no way to avoid them UNTIL they become a collision threat, which can surprise you with as little as 10-12 second to go. Needs to be addressed.

Reference:

http://flarm.com/wp-content/uploads/...ation-1.02.pdf

Flarm is not TCAS, which gives Resolution Advisories to orchestrate between the targets which way to go to avoid each other. Flarm doesn't do this. The pilots have to assess and work cooperatively to ensure this - sometimes you can do that at a distance by taking a decidedly different track and hoping the other guy observes this and doesn't null out your adjustment (zig-zag-bang), sometimes a radio call can (and has) helped. These are scenarios that happen with some regularity.

9B