At 18:01 02 November 2007, John Cagle wrote:
The chute kept fully opening the
first day I used it. You can see it in the video that
I have on my web
site. http://www.caglesonline.com/video/autotows.wmv
Since that day I have
increased the 2 m connecting cable to 4 m. It does
a better job as you can
see in the next video taking the same day and place
that jims glider ground
looped. http://www.caglesonline.com/video/07fallroachlake.wmv

It looks from the videos as if the towing cable is
split in four and looped over the chute so it is trying
to keep it closed only because of the tension in the
cable. I think the chute is almost bound to open with
this arrangement. In all the ground launch cables I
have seen and used - for both winch and auto tow -
the strop attached to the glider goes directly to the
apex of the parachute so that the chute itself is part
of the cable and is kept closed by its own tension.

And 65 or 70 mph seems far too fast. At any reasonable
launch angle the glider airspeed is considerably more
than the tow car speed so for a good launch at say
55 or 60 kt into a light wind, the car should be doing
no more than 30 or 40 mph.

Neil