At 00:59 21 December 2016,
wrote:
On Tuesday, December 20, 2016 at 3:00:06 PM UTC-7, Don
Johnstone wrote:
At 23:33 16 December 2006, Derek Copeland wrote:
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
Yep, what he said.
If you take a winch launch with a really skilled winch driver you
will=20
experience a constant speed all the way up the launch. How is
that=20
done? There are a combination of things that can give clues to
the=20
winch driver, the bow in the cable, if it is wire, does not work
so=20
well with dynema/sky rope. Marked throttle settings as on a=20
Skylaunch winch can help but it really is a matter of feel
and=20
experience. For most glass gliders 55-65kts seems to work
best.
I always reduce power at the top, back to idle once the glider
gets=20
near to the max angle, instigating a back release, this avoids
the=20
possibility of a loop if the cable is released under tension. It
is=20
absolutely essential to ensure that the power is cut, before
the=20
glider is vertically over the winch in nil/very low headwind=20
conditions, it is very unpleasant to have 1000ftl of cable drop
on top=20
of the winch, it it can take a bit of time to get it off as well.

If you know how to fly you can have exactly the airspeed you want
all the
w=
ay up the launch. =20

The winch does not and, in fact, cannot control glider airspeed.
The
pilot=
is the only one who can do that. The winch merely controls
power (think
t=
hrust). It works exactly as with airplanes, pitch controls airspeed
and
po=
wer (thrust) controls rate of climb. The pilot merely adjusts pitch
attitu=
de as necessary to maintain the desired airspeed.

Reduce winch power and the rate of climb (angle) decreases but
the
airspeed=
is unchanged. Reduce it all the way to zero and the glider is left
in a
g=
lide at the desired airspeed. Increase power and the rate of climb
(angle)=
increases but the airspeed stays the same. Increase it too much
and the
w=
eak link breaks - at exactly the desired airspeed - or the glider
runs out
=
of up elevator and the pilot must then ask for less power.

It's really very simple.

Ha Ha, good one. Not done much winching then Bill