At 14:01 18 July 2009, john hawkins wrote:
I would love to see wich operations at local GA aiports but seems to me
the

length required (3X the expected altitude) is a problem. Currently I fly
out
of a 2500 ft strip. there is amybe 500 ft pas the runway that is
available

to locate the winch so 1000 release height is the most I could get. Not
much
to find a thermal with in flat eastern noth carolina.

If you use a decent winch, such as a Skylaunch, and Dyneema cable you
should be able to get heights of about 45% of the cable run (2500 + 500 =
3000ft) in zero headwind. That should give you about 1300ft, and even
more if you can launch into a headwind.

I also fly from a flat site in the UK and can usually get away from such
heights (a bit more in our case as we have a longer run). You just have to
look hard for thermal clues, such as other gliders circling, birds taking
off, and newly forming cumulus clouds. Often the winch or the winch cable
will trigger off a thermal, so it is often worth turning downwind straight
off the top of the launch. This was a tip given to me by an old and very
talented soaring glider pilot many years ago. This is the thermal that
people always find (too low down to use) on the base leg, if they
initially head off upwind!

Derek Copeland