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Old December 16th 06, 11:33 PM posted to rec.aviation.soaring
Derek Copeland
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Posts: 65
Default How to get maximum height on a winch launch?

I thought that was exactly the point I was trying to
make! Stick position is type dependent. Where you hold
the stick and how much you have to pull back, or push
forward, may be different to what you are used to,
if you fly a different type of glider. It depends on
the hook position, the exact c of g and centre of pressure,
and the trim position. The advice I gave was to hold
the stick in a position that gives the optimum angle
of climb for your type of winch. Full stop, period!

Real life winch launching takes place using different
types of gliders in differing wind strengths. No one
throttle setting can cover all cases. If you launched
a slow glider (e.g. a K8) into a 45 knot headwind,
you could stop the winch altogether once it has got
airborne and allow it to launch like a kite. The wind
would be providing the energy while the winch would
just act as an anchor point on the ground. Conversely
launching a heavy two seater on a still day with a
moderately powerful winch might require absolutely
full throttle.

Derek Copeland

At 18:12 16 December 2006, Ian wrote:

Dan G wrote:
Ian wrote:


And that was a surprise? Find yourself another club,
man, because if
headwinds on a winch launch are unexpected your current
lot are going
to damage someone one day.


Easy now, my club has a long safety record any would
be proud of. AFAIK
there's never been a winch launch accident. In that
particular example
there was a very strong wind gradient. I was using
as an illustration
of the belief that K21s can take everything the winch
gives.


I am glad to hear about the safety record. I only hope
they can keep
it.

No. I think it's bad advice. Yes, you should aim
to have a proper climb
angle and air speed, but the stick position is irrelevant.
Just use
enough to do what's needed.


Well, 'find what stick position will hold them at
about 45 degrees to
the horizon AND give a safe speed' and 'you should
aim to have a proper
climb angle and air speed' seems to be the same thing...


No, they are completely different. Stick position is
irrelevant. All
that matters is whether you need to move it.

Let me give a simple example. The exact position of
the temperature
lever on a shower doesn't matter, does it? If it's
too hot you move it
'cold' a bit and if it's too cold you move it 'hot'
a bit. You don't
say 'I'll have a position 5 shower, no matter how hot
that is'.

Same with the stick.

Ian