Guy Acheson wrote:

Take a look a Wings and Wheels website. They sell
several portable collision avoidance systems (PCAS).
One goes for 289 USD. Another for 499 USD. A fairly
sophisticated unit goes for 1700 USD. All work with
the transponder system. A couple function off AA batteries
so the concerns about power consumption are also handled.

Umm, for these PCAS systems to work, the threat aircraft have to have
transponders, which do draw considerable power. So if you want the PCAS
in the other glider to notice you, plan on a minimum 500 ma more current
drain from your 12 volt battery, not a couple of AA batteries.

Again, IMHO sailplanes are aircraft, not toys. Transponders
work and are not that expensive.

Looking at the Wings and Wheels website you mention, I see the cheapest
transponder with encoder and antenna is US$1900, and can easily be
$3000+ with installation by an aircraft mechanic. More, if you have to
install an additional battery and it's mounting and wiring. Expensive by
my standards.

Not that I'm against transponders: I do have one in my glider. My cost
was "only" $1850 because I was able to install it myself and I didn't
need more batteries. Where I fly, airliners and airplanes are the
principal collision hazard, not other gliders. FLARM was developed for
glider pilots whose main hazard is other glider pilots, and for them an
$US800 (installed!) FLARM is more effective and a lot cheaper than a
transponder.

FLARM was never intended to nor claimed to solve the all collision
problems everywhere in the world, yet it's detractors argue that because
it doesn't, it's worthless and doomed to failure. Each region, perhaps
each pilot, must determine the threat he faces and it's appropriate
response, such FLARM, transponders, looking out the canopy, or just
trusting to luck.

--
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"