Bert Willing wrote:
"Marc Ramsey" wrote in message
. com...
I also suspect that FLARM won't do much to help where I'm most concerned
about a collision with another glider, the ridge running down the White
and Inyo mountains near the CA/NV border. FLARM advertises an effective
range of 2-3 km, or 1 to 1.5 nm. Given a head-on approach between two
gliders, each running at a TAS of 150 knots, you'll be lucky to get 10
seconds of warning. Might work for an ex-fighter pilot, but that's not
much time for someone like me...

You're wrong there, Marc. I'm not an ex-fighter pilot, and I had this
warning from my Flarm on the ridge. I took an evasive action and we
didn't collide. 10 sec is a lot when something is yelling at you.

Real world experience definitely trumps my speculation.

By the way, if anyone here in the US is interested, for another project
I've found multiple sources of FCC approved (no conformance testing
required, if used with specific antennas) 900 MHz RF modules with as
much as 20 mile line of sight range using 1/2 wave whip antennas. There
might be a way to do this without a huge up-front hardware and
certification costs. Software and testing would still be a big effort...

Marc