You should not necessarily point the glider at the winch, you should point
it in the direction that the cable is going to take. If there is a bow in
the cable then the glider should not point at the winch but towards the
bow so that yaw is not induced.
Of course the ideal and proper situation is that the cable runs straight
from the winch to the takeoff point when the cable direction and the winch
are both in the same direction.

The correct thing to do if a wing drops is to release the cable, semantics
maybe but can we please get the terminology right at least.

Just to illustrate the point many years a go a gliding site in the UK
winch launched on a dog leg, the winch cable changed direction halfway
down the run by being taken round a telegraph pole and the launch was
always towards the pole. The change in direction when the cable reached
the top of the pole and slipped off was interesting, the good news was
that CofG hooks were not common so the pull of the cable helped to damp
the yaw induced. I would not want to do it in a modern glider with a CofG
hook, damm dangerous I would think.



At 07:30 26 June 2009, Derek Copeland wrote:
For Christs sake Bill! Lasham is the largest and most professional
gliding
club in the UK and we do about 10,000 winch launches per year, 9,999 of
which go without incident. We do know what we are doing. We either point
the glide directly at the main winch, or just slightly upwind of it in a
crosswind to reduce any initial yaw due to weather cocking.

The K13 incident was caused by a gust, and the glider was landed without
damage or injury. A similar wing drop during an aerotow would be
considered quite unremarkable. The correct thing to do is to pull off if
a
wing drops during a winch launch.

Derek Copeland

At 03:42 26 June 2009, bildan wrote:
On Jun 24, 7:00=A0pm, 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
o=
f
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
cas=
e
with the more forward release on older gliders. Perhaps that might
explai=
n
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.