To add some spice - I personally watched two bad winch accidents, each
had to do with power failure of the winch/too low airspeed. In both
cases there was direct radio communication between glider and winch.


Of course having radio connection does not mean you can just let the
launch happen. You still have to fly it and react to whatever
situation arises. First, you have to use the radio. Second you have to
use it before it's to late and third and most important: never rely on
the use of radio of having any effect on the launch.
I still fail to understand why any winch or cabel failure should lead
to an accident. With or without radio. With or without wind. With or
without water ballast.
Be prepared.

Marcel