On Jun 9, 8:23*pm, Evan Ludeman wrote:
PCAS is useless for gliders flying intentionally in proximity, e.g. in
thermals. *Range is based on signal strength, altitude is based on
pressure altitude encoder and there's no directionality. *Best that
PCAS would tell you is that there are "n" gliders close to you. *It
certainly can't give collision warning.

-Evan Ludeman / T8

Sorry Evan but that is not completely correct. While I agree that
PCAS can only offer very limited collision avoidance it certainly does
help. Speak of the devil I have video to prove it! Check out the
following which is just one of many videos showing close sailplane
formation and PCAS proximity warnings. Note my PCAS warns me that I
am drifting too close to the other transponder equip ship. I am all
for Power Flarm and have one on order but please note that the PCAS
does offer at least a little bit of help. Better than nothing...that
is when it works. My Zaon PCAS has stopped working 3 times with no
warning other than it didn't alert me to a close aircraft giving me a
hint that it stopped working again. Grrrr!

http://www.youtube.com/watch?v=n2H4SQpjRxc

The PCAS warnings come at :18, :27 (note how the sailplane is drifting
towards me), :46, 1:14 and on and on throughout the video. Again,
I'll take Flarm any day of the week but I guess they have to start
shipping our brick units first. Another Grrr.

Take care,
Bruno - B4