On Jun 24, 7:00*pm, Don Johnstone wrote:
What is particularly interesting in both the video and the photographs is
the direction the glider is pointing relative to the cable. In the video
the glider can be seen to yaw as the cable tightens and then further yaw
as the it starts to move.
In the photographs it is clear that the glider is pointing to the right of
the direction of the cable AND stangely is pointed in the same direction as
the K13 parked behind it, a co-incidence perhaps. In both cases it would
appear possible that the glider was not lined up with the cable prior to
launch so that as soon as the cable moved yaw was induced. With a CofG
hook the glider will be more unstable about the yaw axis than was the case
with the more forward release on older gliders. Perhaps that might explain
why this appears to be a "new" phenomenon.

Nope, they lined it up at an angle to the wire then all the other
stuff compounded the problem. There are other videos from Lasham with
the gliders improperly staged which show a similar wobbly takeoff. If
the gilder isn't pointing at the winch, the takeoff will be
'interesting'. Unfortunately, some people in the US are showing the
k-13 photo sequence as proof that winches are too dangerous to use.
This actually forced me to add a paragraph in my winch training
syllabus cautioning pilots to aim gliders at the winch - which any kid
launching a balsa glider with a rubber band would understand without
being told.

To be fair, there very well could have been a wind event that we, in a
dustier climate, would call a "dust devil" which couldn't be seen in
lush green England. We would see it coming and stand down until the
thing passed - then launch and go chase it for the lift it marks.