Don Johnstone wrote:

Unless 100% of gliders have it installed it cannot be effective,surely you can
see that.

Not really Don, if any percentage of gliders is equipped with Flarm, the
risk of collision is reduced, surely you can see that.

Realistically persuading sufficient pilots in the UK
to fit FLARM to make it anywhere near effective has
about the same chance as winning the national lottery.

Well, I do not know about UK, but I do know that at my club, DDSC in
Queensland Australia we have achieved a nearly 100 % compliance within
few weeks. Upon request by the club committee, enough money was donated
by members to equip all club gliders and tugs. Almost all private
gliders were also fitted with Flarm.
In a recent competition 60 or so gliders were equipped with Flarm. A
questionnaire and interviews after the comp showed that all pilots were
very positive about the Flarm.
So, I am not so sure that it will be so difficult to get a high level of
voluntary compliance.
The Australian Flarm (I am not sure about the European version) will be
able to receive communication from transponders and thus give
information on the power aircraft.
I find your position quite interesting Don. Clearly you have no
experience with Flarm, yet you dismiss it. Likewise you seem to able to
speak on behalf of a vast majority of UK pilots - no mean feat.
Clearly Flarm is not a device that will solve all the problems. Lookout
is important and will remain so. However it has failed many time, I
guess in some cases because it was not particularly good, but in other
cases it could have been due to physiological limitation of pilots.
Equally you cannot see in your blind spot, Flarm can.
Personally I have only flown with Flarm 2 or 3 times. I have found that
it showed me gliders I did not see, once dead ahead but well bellow, so
I have changed course slightly and spotted it. One other time at my 10
o'clock a long way away. Overall I have found that it has improved my
situational awareness as the Australian Flarm actually shows you where
the gliders are (well +- 22.5 deg).
Finally we all spend money on chutes (about 3x as much) and yet their
potential to save one is quite limited.

regards

paul