How to get maximum height on a winch launch?

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
experience a constant speed all the way up the launch. How is that
done? There are a combination of things that can give clues to the
winch driver, the bow in the cable, if it is wire, does not work so
well with dynema/sky rope. Marked throttle settings as on a
Skylaunch winch can help but it really is a matter of feel and
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
near to the max angle, instigating a back release, this avoids the
possibility of a loop if the cable is released under tension. It is
absolutely essential to ensure that the power is cut, before the
glider is vertically over the winch in nil/very low headwind
conditions, it is very unpleasant to have 1000ftl of cable drop on top
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 way up the launch.

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 thrust). It works exactly as with airplanes, pitch controls airspeed and power (thrust) controls rate of climb. The pilot merely adjusts pitch attitude 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 glide 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 weak 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.

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

On Tue, 20 Dec 2016 16:59:34 -0800 (PST),
wrote:


If you know how to fly you can have exactly the airspeed you want all the way up the launch.

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 thrust). It works exactly as with airplanes, pitch controls airspeed and power (thrust) controls rate of climb. The pilot merely adjusts pitch attitude 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 glide 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 weak 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.

Hi Bill,

unfortunately it's not that simple. Your description does not even
remotely match the experiences I made I made in the last couple of
thousand winch launches.

Best regards
Andreas

Actually if we had better designed winches Bill would be correct.

Unfortunately the gliding movement certainly in the UK, but also in Europe,
seems to have taken the "Easy" option of Skylaunch winches.
400hp and auto Transmission mean that the pilot has little control of the
airspeed during the launch.

Too fast? ease back, go even faster!

PF

At 13:01 21 December 2016, Andreas Maurer wrote:
On Tue, 20 Dec 2016 16:59:34 -0800 (PST),
wrote:


If you know how to fly you can have exactly the airspeed you want all
the
way up the launch.

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 thrust). It works exactly as with airplanes, pitch controls
airspeed and power (thrust) controls rate of climb. The pilot merely
adjusts pitch attitude 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 glide 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 weak 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.

Hi Bill,

unfortunately it's not that simple. Your description does not even
remotely match the experiences I made I made in the last couple of
thousand winch launches.

Best regards
Andreas

On Wednesday, December 21, 2016 at 8:15:04 AM UTC-6, Peter F wrote:
Actually if we had better designed winches Bill would be correct.

Unfortunately the gliding movement certainly in the UK, but also in Europe,
seems to have taken the "Easy" option of Skylaunch winches.
400hp and auto Transmission mean that the pilot has little control of the
airspeed during the launch.

Too fast? ease back, go even faster!

PF

Ah, so you took the American Approach. Nothing Exceeds like Excess! Or, there is nothing that cannot be improved with application of more cubic inches.

Steve Leonard

On Wednesday, December 21, 2016 at 6:01:50 AM UTC-7, Andreas Maurer wrote:
On Tue, 20 Dec 2016 16:59:34 -0800 (PST),
wrote:


If you know how to fly you can have exactly the airspeed you want all the way up the launch.

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 thrust). It works exactly as with airplanes, pitch controls airspeed and power (thrust) controls rate of climb. The pilot merely adjusts pitch attitude 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 glide 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 weak 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.

Hi Bill,

unfortunately it's not that simple. Your description does not even
remotely match the experiences I made I made in the last couple of
thousand winch launches.

Best regards
Andreas

It is just that simple and it PRECISELY matches my experiences in my last couple of thousand launches.

On Wednesday, December 21, 2016 at 7:15:04 AM UTC-7, Peter F wrote:
Actually if we had better designed winches Bill would be correct.

Unfortunately the gliding movement certainly in the UK, but also in Europe,
seems to have taken the "Easy" option of Skylaunch winches.
400hp and auto Transmission mean that the pilot has little control of the
airspeed during the launch.

Too fast? ease back, go even faster!

PF



400HP is good. Automatic transmissions are evil.

At 21:19 21 December 2016,
wrote:
On Wednesday, December 21, 2016 at 6:01:50 AM UTC-7,
Andreas Maurer wrote:
On Tue, 20 Dec 2016 16:59:34 -0800 (PST),
wrote:
=20
=20
If you know how to fly you can have exactly the airspeed you
want all
th=
e way up the launch. =20

The winch does not and, in fact, cannot control glider
airspeed. The
pi=
lot is the only one who can do that. The winch merely controls
power
(thin=
k thrust). It works exactly as with airplanes, pitch controls
airspeed
and=
power (thrust) controls rate of climb. The pilot merely adjusts
pitch
att=
itude as necessary to maintain the desired airspeed.

Reduce winch power and the rate of climb (angle) decreases
but the
airsp=
eed is unchanged. Reduce it all the way to zero and the glider is
left in
=
a glide at the desired airspeed. Increase power and the rate of
climb
(ang=
le) increases but the airspeed stays the same. Increase it too
much and
th=
e weak link breaks - at exactly the desired airspeed - or the glider
runs
o=
ut of up elevator and the pilot must then ask for less power.

It's really very simple.
=20
Hi Bill,
=20
unfortunately it's not that simple. Your description does not
even
remotely match the experiences I made I made in the last
couple of
thousand winch launches.
=20
Best regards
Andreas

It is just that simple and it PRECISELY matches my experiences in
my last
c=
ouple of thousand launches.

Well Bill, we will have to differ because it certainly does not match
my experience in the last 10,000 launches. Both the MVG and
Skylaunch winch will exceed the max winch launch speed easily
whatever you do in the cockpit, except of course yawing to tell the
winch driver he is applying too much grunt.
If you think winch launching is simple it is going to bite you one
day.

On Wed, 21 Dec 2016 13:19:17 -0800 (PST),
wrote:

On Wednesday, December 21, 2016 at 6:01:50 AM UTC-7, Andreas Maurer wrote:
On Tue, 20 Dec 2016 16:59:34 -0800 (PST),
wrote:

The winch does not and, in fact, cannot control glider airspeed. The pilot is the only one who can do that.

It does. Reduce power, and the glider pilot will need some quick
reaction to lower the nose and keep up 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 glide at the desired airspeed.

Nope. Reduce winch power to zero and the pilot needs a very quick
reaction to lower the nose and keep airspeed up. Without reaction the
glider pilot is very, verfy close to stall and crash.
Seen a couple of bad crashes due to winch failure.




Increase power and the rate of climb (angle) increases but the airspeed stays the same.

Never experienced that ever. Not in a light Ka-8, not in a a really
heavy open class double seater.

Increase it too much and the weak link breaks - at exactly the desired airspeed - or the glider runs out of up elevator and the pilot must then ask for less power.

From all 60+ gliders I've flown in a winch launch only one prototype
ever ran out of elevator authority.

Maybe us Europeans are doing something fundamentally different.