Using Plasma Rope For Winch Tows

[Craig Freeman]

We recently converted from 3/16 7x9 cable to 3/16 plasma rope on our winch.
"Plasma", made from Honeywell "Spectra" fiber, seems to have some real
advantages over wire or cable. Some benifits include light weight, 11.48lbs
per thousand, (that's not much even converted to metric!!), hollow braid
(no twisting), 5000 lb breaking strength (that a lot even converted to
metric!!), 25% increase in launch heights. We operate from asphalt and
it seems to be holding up wery well. Expensive? Yes! However in our
environment it promises to far outlast steel which would make it cheaper
in the long run plus the added benifits. Sorry this sounds like a commerical
I was just so tired of that !@#$@#%%^# wire. If anyone else has any experience
with this stuff is there anything we should be looking out for?

Happy Winching,
Craig-

[Bill Daniels]

"Craig Freeman" > wrote in message
...
> We recently converted from 3/16 7x9 cable to 3/16 plasma rope on our
winch.
> "Plasma", made from Honeywell "Spectra" fiber, seems to have some real
> advantages over wire or cable. Some benifits include light weight,
11.48lbs
> per thousand, (that's not much even converted to metric!!), hollow braid
> (no twisting), 5000 lb breaking strength (that a lot even converted to
> metric!!), 25% increase in launch heights. We operate from asphalt and
> it seems to be holding up wery well. Expensive? Yes! However in our
> environment it promises to far outlast steel which would make it cheaper
> in the long run plus the added benifits. Sorry this sounds like a
commerical
> I was just so tired of that !@#$@#%%^# wire. If anyone else has any
experience
> with this stuff is there anything we should be looking out for?
>
> Happy Winching,
> Craig-

You should be looking out for:
1. A lot of fun not interrupted by wire tangles.
2. A lot more soaring from the higher release heights.
3. A lot more soaring from the lower costs of the launch.
4. A lot fewer band-aids consumed due to fewer wire cuts on your hands.
5. No wire failures due to rust.

The stuff gets ugly and fuzzy as it wears out so you have a lot of visual
warning long before it gets too weak to use. BTW, I think washing it
occasionally might extend the usable life - you'll have to figure out how to
do that.

I just checked (again) the maximum safe working load of 3/16" 7x7 steel.
It's about 900 pounds if there are no dynamic loads. Spectra is WAY
stronger than that and it doesn't seem to be as sensitive to dynamic loads.

Thanks for the report.

Bill Daniels

[Gale Henslee]

This is very interesting to me - I am building a winch, and have been
thinking (agonizing) over the best cable to buy. Can you provide a
reference where I can find more information, and also tell me where
you bought yours? Thanks

[Simon Walker]

How does one splice it you get a cable break or a birds
nest on the winch drum and need to cut it to untangle?






At 22:54 28 July 2003, Bill Daniels wrote:
>
>'Craig Freeman' wrote in message
...
>> We recently converted from 3/16 7x9 cable to 3/16
>>plasma rope on our
>winch.
>> 'Plasma', made from Honeywell 'Spectra' fiber, seems
>>to have some real
>> advantages over wire or cable. Some benifits include
>>light weight,
>11.48lbs
>> per thousand, (that's not much even converted to metric!!),
>>hollow braid
>> (no twisting), 5000 lb breaking strength (that a lot
>>even converted to
>> metric!!), 25% increase in launch heights. We operate
>>from asphalt and
>> it seems to be holding up wery well. Expensive? Yes!
>>However in our
>> environment it promises to far outlast steel which
>>would make it cheaper
>> in the long run plus the added benifits. Sorry this
>>sounds like a
>commerical
>> I was just so tired of that !@#$@#^# wire. If anyone
>>else has any
>experience
>> with this stuff is there anything we should be looking
>>out for?
>>
>> Happy Winching,
>> Craig-
>
>You should be looking out for:
>1. A lot of fun not interrupted by wire tangles.
>2. A lot more soaring from the higher release heights.
>3. A lot more soaring from the lower costs of the launch.
>4. A lot fewer band-aids consumed due to fewer wire
>cuts on your hands.
>5. No wire failures due to rust.
>
>The stuff gets ugly and fuzzy as it wears out so you
>have a lot of visual
>warning long before it gets too weak to use. BTW,
>I think washing it
>occasionally might extend the usable life - you'll
>have to figure out how to
>do that.
>
>I just checked (again) the maximum safe working load
>of 3/16' 7x7 steel.
>It's about 900 pounds if there are no dynamic loads.
> Spectra is WAY
>stronger than that and it doesn't seem to be as sensitive
>to dynamic loads.
>
>Thanks for the report.
>
>Bill Daniels
>
>

[goneill]

At Auckland gliding club we are using plain standard rope (aerotow)and find
this works just as well as the more expensive spectra and others like it.The
only difference is in the initial lift off the ground and rotation .The rope
is more elastic and if you do not get load on the cable quickly and maintain
it, an oscillation can start between glider and winch. result: slow fast
slow fast etc launch. The main advantage is its cheap and available
everywhere.
Splicing is the same as aero tow ropes but double the length.
We use the correct weak link for the a/c type
We have found the increase in height is roughly the same as spectra and
others like it.
gary

"Craig Freeman" > wrote in message
...
> We recently converted from 3/16 7x9 cable to 3/16 plasma rope on our
winch.
> "Plasma", made from Honeywell "Spectra" fiber, seems to have some real
> advantages over wire or cable. Some benifits include light weight,
11.48lbs
> per thousand, (that's not much even converted to metric!!), hollow braid
> (no twisting), 5000 lb breaking strength (that a lot even converted to
> metric!!), 25% increase in launch heights. We operate from asphalt and
> it seems to be holding up wery well. Expensive? Yes! However in our
> environment it promises to far outlast steel which would make it cheaper
> in the long run plus the added benifits. Sorry this sounds like a
commerical
> I was just so tired of that !@#$@#%%^# wire. If anyone else has any
experience
> with this stuff is there anything we should be looking out for?
>
> Happy Winching,
> Craig-

[Simon Walker]

Do you have any idea how it stacks up cost wise compared
to wire rope?
i.e. twice, three. four times as expensive??
Thanks.


At 22:36 28 July 2003, Craig Freeman wrote:
>We recently converted from 3/16 7x9 cable to 3/16 plasma
>rope on our winch.
>'Plasma', made from Honeywell 'Spectra' fiber, seems
>to have some real
>advantages over wire or cable. Some benifits include
>light weight, 11.48lbs
>per thousand, (that's not much even converted to metric!!),
>hollow braid
>(no twisting), 5000 lb breaking strength (that a lot
>even converted to
>metric!!), 25% increase in launch heights. We operate
>from asphalt and
>it seems to be holding up wery well. Expensive? Yes!
>However in our
>environment it promises to far outlast steel which
>would make it cheaper
>in the long run plus the added benifits. Sorry this
>sounds like a commerical
>I was just so tired of that !@#$@#^# wire. If anyone
>else has any experience
>with this stuff is there anything we should be looking
>out for?
>
>Happy Winching,
>Craig-
>

[George William Peter Reinhart]

"Plasma Rope"
Brand name?
Mfr.?
Source?
Thanks.
Cheers!

[Wallace Berry]

In article >,
(Craig Freeman) wrote:

> We recently converted from 3/16 7x9 cable to 3/16 plasma rope on our winch.
> "Plasma", made from Honeywell "Spectra" fiber, seems to have some real
> advantages over wire or cable. Some benifits include light weight, 11.48lbs
> per thousand, (that's not much even converted to metric!!), hollow braid
> (no twisting), 5000 lb breaking strength (that a lot even converted to
> metric!!), 25% increase in launch heights. We operate from asphalt and
> it seems to be holding up wery well. Expensive? Yes! However in our
> environment it promises to far outlast steel which would make it cheaper
> in the long run plus the added benifits. Sorry this sounds like a commerical
> I was just so tired of that !@#$@#%%^# wire. If anyone else has any experience
> with this stuff is there anything we should be looking out for?
>
> Happy Winching,
> Craig-



Well, I was waiting for someone from the Memphis club to post. However,
no one has so far, so I'll have a go.

The Memphis club purchased Glen Lawler's winch a few months ago. My
club, Southern Eagles, used this winch with excellent results for a
couple of years. We only stopped using the winch when we moved to an
airport with crossing runways where we had marginal room for the cable.

A couple of weeks ago, Glen Klingshirn and I had the good fortune to be
invited up to Memphis to train their guys on winch launching. Just as an
aside, I have to say that you won't find a better bunch of folks to fly
with. The hospitality and fellowship was superb. They are also making
the ultimate contribution to the future of soaring in the U.S.: The
Memphis Soaring Society has established their own field at Cherry
Valley, Arkansas. They are doing it right with a huge field, immense
hangar and a beautiful clubhouse under construction.

Anyway, the MSS has equipped one drum on the (two drum) winch with
Spectra. The original wire rope is on the other drum. After a few
launches with the cable, we switched to the Spectra and didn't look
back. The Spectra seems to give higher launches although we didn't do
enough launches with the wire to make a valid comparison. The Spectra
had no more noticeable stretch than the cable so we didn't have any
"bungee" dynamics to work around. To me the biggest, and unexpected,
advantage of the Spectra was that it did not have enough mass to throw
itself into a tangle. During training of new winch drivers, we had a few
incidents which would have put a tangle in wire rope, but with the
Spectra, there was never a tangle of any kind. The Spectra also seemed
to be holding up well through 30 launches or so. The only minor problem
with the Spectra is that it has so little mass that the cable end strop
would fall through the chute unless the winch driver got the power back
on quickly after the glider released. This was just a problem with winch
driver trainees and resolved after each driver got more experience.

It may be that exotic stuff like Spectra is not needed for a winch. The
dacron rope that we have used for auto launch is very similar in
appearance and has almost no stretch like the Spectra. It is also
abrasion resistant. It is not as strong as Spectra but is plenty strong
enough. It may do as well as Spectra on a winch and is cheaper.

Wallace (help stamp out winchophobia) Berry

[Craig Freeman]

Simon Walker > wrote in message >...
> Do you have any idea how it stacks up cost wise compared
> to wire rope?
> i.e. twice, three. four times as expensive??
> Thanks.
>
>
Its three to four times as much. However, after having experienced
the frustrastions associated with wire for the last two years, this
is like heaven. We pull on a paved runway. Any wire splice or small
kink wears at an extrodinary rate. Plasma rope lays flat and does not
kink,
the light wieght reduces effect of friction on the pull and allows
for the rope to become airborn much quicker all reducing the wear
factor. In the long run Plasma may be cost effective even without the
added benifits of ease of use, added launch hieght ect. . Plasma has a
very small tendency to "birds
nest" as it has very little stretch so no recoil if released
under tension. Also it is relaxed on the spool so it does not try
to grow if the speed suddenly slows on the pull out. Our winch has a
48" drum and no level wind. Plasma does not self level as well as wire
did however it is satisfactory. More info on Plasma here
www.thecortlandcompanies.com/psrope/ .

Craig-

[Mark Busse]

Wallace you did a great job on this write up . Sorry I have not post
for a long time, I was tired of getting all the porn after my address
was mined out of the archives (I just figured out why some of the
regulars put "DELETE" in their address line, I will see how well it
works)

Again Wallace did such a good job there is not much for me to add. We
have now been operating it each weekend,but due to the treelines we
can only pull 3600' of PLASMA not SPECTRA we went with the more
expensive stuff but I think the SPECTRA will work as well. I thought
we would have done a more accurate comparision of steel vs. Plasma but
no one will pull the steel out anymore. So we have a two drum winch
and we operate it as if it had only one, I can hardly wait for us to
budget the funds to buy rope for the one.
We have not had any launches with strong headwinds in fact there has
been little or no wind at all. The steel launches we made were
700'-900' then the Plasma were 1000'-1200' I wish we could pull out
1500' more rope maybe someday.
There are a couple of note Wallace did not mention.
1. Winch drive cannot read cable tention by observation of the droupe
THERE IS NO DROUPE!!! It looks like the glider is being shot in the
belley by a Purple laser beam.
2. One man can pull extra slack if the strope is too short for a
hookup.
3. No snags or injurys

BTW Dick Kilburn at PSROPE.COM is the salesman that handles our
account, he has been waiting a long time for us to move to our new
gliderport so we could operate the winch. We have about 100 launches
on the rope to date and it shows no sign of wear.
Mark

> >
> > Well, I was waiting for someone from the Memphis club to post. However,
> > no one has so far, so I'll have a go.
> >
> > The Memphis club purchased Glen Lawler's winch a few months ago. My
> > club, Southern Eagles, used this winch with excellent results for a
> > couple of years. We only stopped using the winch when we moved to an
> > airport with crossing runways where we had marginal room for the cable.
> >
> > A couple of weeks ago, Glen Klingshirn and I had the good fortune to be
> > invited up to Memphis to train their guys on winch launching. Just as an
> > aside, I have to say that you won't find a better bunch of folks to fly
> > with. The hospitality and fellowship was superb. They are also making
> > the ultimate contribution to the future of soaring in the U.S.: The
> > Memphis Soaring Society has established their own field at Cherry
> > Valley, Arkansas. They are doing it right with a huge field, immense
> > hangar and a beautiful clubhouse under construction.
> >
> > Anyway, the MSS has equipped one drum on the (two drum) winch with
> > Spectra. The original wire rope is on the other drum. After a few
> > launches with the cable, we switched to the Spectra and didn't look
> > back. The Spectra seems to give higher launches although we didn't do
> > enough launches with the wire to make a valid comparison. The Spectra
> > had no more noticeable stretch than the cable so we didn't have any
> > "bungee" dynamics to work around. To me the biggest, and unexpected,
> > advantage of the Spectra was that it did not have enough mass to throw
> > itself into a tangle. During training of new winch drivers, we had a few
> > incidents which would have put a tangle in wire rope, but with the
> > Spectra, there was never a tangle of any kind. The Spectra also seemed
> > to be holding up well through 30 launches or so. The only minor problem
> > with the Spectra is that it has so little mass that the cable end strop
> > would fall through the chute unless the winch driver got the power back
> > on quickly after the glider released. This was just a problem with winch
> > driver trainees and resolved after each driver got more experience.
> >
> > It may be that exotic stuff like Spectra is not needed for a winch. The
> > dacron rope that we have used for auto launch is very similar in
> > appearance and has almost no stretch like the Spectra. It is also
> > abrasion resistant. It is not as strong as Spectra but is plenty strong
> > enough. It may do as well as Spectra on a winch and is cheaper.
> >
> > Wallace (help stamp out winchophobia) Berry
> >

[Robert Ehrlich]

Mark Busse wrote:
> ...
> We have not had any launches with strong headwinds in fact there has
> been little or no wind at all. The steel launches we made were
> 700'-900' then the Plasma were 1000'-1200' I wish we could pull out
> 1500' more rope maybe someday.
> ...

I find these heights abnormally low. I expect about 40% of cable length,
this is what we used to reach in my club with steel cable and no wind, now
the engine does no more provide its full poweer, so the height is sligtly
reduced (350m instead of 400m with 1000m cable).

[Andreas Maurer]

On Thu, 31 Jul 2003 09:11:43 +0000, Robert Ehrlich
> wrote:

>Mark Busse wrote:
>> ...
>> We have not had any launches with strong headwinds in fact there has
>> been little or no wind at all. The steel launches we made were
>> 700'-900' then the Plasma were 1000'-1200' I wish we could pull out
>> 1500' more rope maybe someday.
>> ...
>
>I find these heights abnormally low. I expect about 40% of cable length,
>this is what we used to reach in my club with steel cable and no wind, now
>the engine does no more provide its full poweer, so the height is sligtly
>reduced (350m instead of 400m with 1000m cable).

Indeed. We are also testing a PE-cable instead of steel cable, with a
cable length of about 3.300 ft, and height difference between seteel
and the light PE cable is very hard to tell - definitely not an as
huge difference as Mark writes.
Bye
Andreas

[wy]

> > ...
> > We have not had any launches with strong headwinds in fact there has
> > been little or no wind at all. The steel launches we made were
> > 700'-900' then the Plasma were 1000'-1200' I wish we could pull out
> > 1500' more rope maybe someday.
> > ...
>
> I find these heights abnormally low. I expect about 40% of cable length,
> this is what we used to reach in my club with steel cable and no wind, now
> the engine does no more provide its full poweer, so the height is sligtly
> reduced (350m instead of 400m with 1000m cable).

My guess is that you are out side of north america. European winch
technology is far ahead of anything we do in the states. Although we do seem
to be experimenting more with the type of cable material a little more. The
fact that we are even talking about it in the states is a huge change from
just ten years ago.

We have been auto towing (off and on) for several years with Dacron rope and
are quite happy with it.

wy

[Bill Daniels]

"wy" > wrote in message
et...
>
> > > ...
> > > We have not had any launches with strong headwinds in fact there has
> > > been little or no wind at all. The steel launches we made were
> > > 700'-900' then the Plasma were 1000'-1200' I wish we could pull out
> > > 1500' more rope maybe someday.
> > > ...
> >
> > I find these heights abnormally low. I expect about 40% of cable length,
> > this is what we used to reach in my club with steel cable and no wind,
now
> > the engine does no more provide its full poweer, so the height is
sligtly
> > reduced (350m instead of 400m with 1000m cable).
>
> My guess is that you are out side of north america. European winch
> technology is far ahead of anything we do in the states. Although we do
seem
> to be experimenting more with the type of cable material a little more.
The
> fact that we are even talking about it in the states is a huge change from
> just ten years ago.
>
> We have been auto towing (off and on) for several years with Dacron rope
and
> are quite happy with it.
>
> wy
>
I suspect release heights will get higher as pilots get more comfortable
with the new winch. I find US pilots are extremely reluctant to enter the
full climb attitude until 200 - 400 feet AGL which significantly reduces the
height achieved.

This conservatism is appropriate when a group is learning new procedures but
it does limit launch heights.

Bill Daniels

[Robert Ehrlich]

Bill Daniels wrote:
>
> "wy" > wrote in message
> et...
> >
> > > > ...
> > > > We have not had any launches with strong headwinds in fact there has
> > > > been little or no wind at all. The steel launches we made were
> > > > 700'-900' then the Plasma were 1000'-1200' I wish we could pull out
> > > > 1500' more rope maybe someday.
> > > > ...
> > >
> > > I find these heights abnormally low. I expect about 40% of cable length,
> > > this is what we used to reach in my club with steel cable and no wind,
> now
> > > the engine does no more provide its full poweer, so the height is
> sligtly
> > > reduced (350m instead of 400m with 1000m cable).
> >
> > My guess is that you are out side of north america. European winch
> > technology is far ahead of anything we do in the states. Although we do
> seem
> > to be experimenting more with the type of cable material a little more.
> The
> > fact that we are even talking about it in the states is a huge change from
> > just ten years ago.
> >
> > We have been auto towing (off and on) for several years with Dacron rope
> and
> > are quite happy with it.
> >
> > wy
> >
> I suspect release heights will get higher as pilots get more comfortable
> with the new winch. I find US pilots are extremely reluctant to enter the
> full climb attitude until 200 - 400 feet AGL which significantly reduces the
> height achieved.
>
> This conservatism is appropriate when a group is learning new procedures but
> it does limit launch heights.
>
> Bill Daniels


I think the time at which you enter the full climb attitude should not
be determined by your altitude but rather by your speed. The main reason
you should not go to quickly to a high nose up attitude is the risk of
stall in case of cable break. In this case, a push down to 0g causes a
ballistic recovery path with a modern glider having a near zero drag
(compared to other involved forces), i.e. the glider flies an arc of a
parabola with a nearly constant horizontal component of speed. This means
that if you start the recovery at 100km/h and 45 degrees nose up, the
horizontal component is 100*sqrt(2) ~ 70km/h and you will reach the top
of the parabola with a speed of 70 km/h, i.e. above stall speed On the
other hand, even with a lot of altitude margin, if you have a cable break
with a high nose up attitude and you don't immediately push to 0g, you
are probably going to stall. If you do it starting from a to low speed, you
will need to continue at 0g past the top of the parabola in order to recover
a speed above the stall speed, and diving toward the ground at low altitude
is a thing any pilot would be reluctant to do.


As "wy" guessed, I am in Europe, more precisely in France. Winches are very
common in Germany and some other european countries, but in France, up to
a not very long time ago, the situation was very similar to that in the US. At the
time when a lot of gliders were built in France, a lot of them had no CG hook.
My knowledge on the subject is only from hearing what older pilots are saying,
since I started only in 1995, but as far as I understand, winch launching in
these years (50 to 80) was perceived as an old fashionned launching method
superceeded by aero tow. The availability of a lot of Rallye's dropped by the
army as tow plane helped that. Now the raising cost of maintenance of these
old planes, the complaints of neighbours of airfields against their noise
and the vanishing of the financial helps from the state are causing a renewed
interest for winching. But a lot of old mentalities remains. There are several
big clubs in the vicinity of Paris (more than 100 members), but my own one is
the only one owning and using a winch. And despite the efforts of the fans
of winch (I am one of them) the winch is highly underused (lowest year 2001 with
only 3 launches).

[Bill Daniels]

"Robert Ehrlich" > wrote in message
...
Snip-----
>
> I think the time at which you enter the full climb attitude should not
> be determined by your altitude but rather by your speed. The main reason
> you should not go to quickly to a high nose up attitude is the risk of
> stall in case of cable break. In this case, a push down to 0g causes a
> ballistic recovery path with a modern glider having a near zero drag
> (compared to other involved forces), i.e. the glider flies an arc of a
> parabola with a nearly constant horizontal component of speed. This means
> that if you start the recovery at 100km/h and 45 degrees nose up, the
> horizontal component is 100*sqrt(2) ~ 70km/h and you will reach the top
> of the parabola with a speed of 70 km/h, i.e. above stall speed On the
> other hand, even with a lot of altitude margin, if you have a cable break
> with a high nose up attitude and you don't immediately push to 0g, you
> are probably going to stall. If you do it starting from a to low speed,
you
> will need to continue at 0g past the top of the parabola in order to
recover
> a speed above the stall speed, and diving toward the ground at low
altitude
> is a thing any pilot would be reluctant to do.
>
Absolutely true. Airspeed is the key.

> As "wy" guessed, I am in Europe, more precisely in France. Winches are
very
> common in Germany and some other european countries, but in France, up to
> a not very long time ago, the situation was very similar to that in the
US. At the
> time when a lot of gliders were built in France, a lot of them had no CG
hook.
> My knowledge on the subject is only from hearing what older pilots are
saying,
> since I started only in 1995, but as far as I understand, winch launching
in
> these years (50 to 80) was perceived as an old fashionned launching method
> superceeded by aero tow. The availability of a lot of Rallye's dropped by
the
> army as tow plane helped that. Now the raising cost of maintenance of
these
> old planes, the complaints of neighbours of airfields against their noise
> and the vanishing of the financial helps from the state are causing a
renewed
> interest for winching. But a lot of old mentalities remains. There are
several
> big clubs in the vicinity of Paris (more than 100 members), but my own one
is
> the only one owning and using a winch. And despite the efforts of the fans
> of winch (I am one of them) the winch is highly underused (lowest year
2001 with
> only 3 launches).

I wouldn't have guessed. Sounds just like the USA.

Bill Daniels

[Bruce Greeff]

I concur - it is about speed (and to some extent altitude), not climb
angle.

The secret is in the winch driver, and the pilot knowing what they are
doing and ensuring a smooth and rapid acceleration appropriate to the
specific aircraft being launched.

We try to have the winch at "full throttle" (which varies depending on
what you are launching) in a smooth 4 second roll. That way the glider
is not snatched, but acceleration is rapid, minimising chances of wing
drops and other excitement.

If your aircraft is set up and trimmed properly you find that the whole
plot works fairly automatically.

Once the tail lifts you are at a speed where you have elevator authority
.. If you move the stick to the neutral position most aircraft lift off
as their speed increases beyond the speed needed to support the weight
(stall) Continuing the slow pull up with progressively more back
pressure on the stick initiate a safe climb, with the aircraft still
accelerating strongly.
By the time you are 100m down the runway and 20m up you have reached
close to Vw, at which point it is safe to rotate into the steep climb. A
smooth but relatively quick rotation will have you safely launching to
maximum height. Because you have enough speed to recover from a cable
break or winch failure, altitude is not particularly important unless
you are very low. If you fly a smooth pull-up into the climb you will
not be at your steepest angle below 30-40m (100+feet)

Some gliders have a tendency to over-rotate or kite, but that is
restricted to older designs as far as I know. In these it is unwise to
pull up too hard under any circumstances.

Interestingly enough if your winch has sufficient torque you will find
that steep climbs actually increase your speed, because you are
describing a larger arc. If your winch does not have sufficient power
reserves you can slow things down by pulling too hard, which is
extremely dangerous.

[Andreas Maurer]

On Thu, 7 Aug 2003 07:52:53 -0600, "Bill Daniels"
> wrote:



>The boundary on the high side of acceleration is the tendency of some
>gliders with high CG's, low hooks and limited down elevator authority to
>pitch-up uncontrollably when a threshold acceleration is exceeded.

Please tell me the names of these gliders. I have NOT heard of a
single one yet that showed this behaviour. Not one.


>Some winch operations deliberately accelerate the glider to a point above
>the Vw airspeed limit at the start of the launch. A short excursion above
>Vw at the start has no adverse effect on wing loads. Of course, the
>airspeed must fall below Vw as the glider enters the full climb attitude.

I wonder whyt use this should have. If the pilot decides to pull back
he will enter a highspeed stall as quickly as if he was slower. And as
long as he's in the 55-60 mph range his speed will always be
completely sufficient to recover if he has a rope break at low
heights.
Having high speed and a steep climb angle is the perfect trigger for a
rope (or weak link) break, therefore it's not a good idea to be too
fast in my opinion.


>This is a situation that cries out for precise winch instrumentation and
>automation. This is why a glider to winch data link is so promising. I
>envision a device in the glider that allows the pilot to set the desired
>acceleration and airspeed before the launch - in effect setting the launch
>parameters of the winch to fit a particular glider/pilot combination.

No idea why you get the idea why such a thing ought to be necessary -
but in my club (as well as in all other clubs I know, and these are
many) the winch drivers are perfectly capable of doing a safe and
efficient winch launch (none of them being a proffessional winch
driver, but having winch duty only half a dozen of days per year).
They get told what glider they are going to tow, and adjust the power
accordingly.


>It is also a case where large power reserves are needed. This is the reason
>the new generation of high power winches are so popular.

The advantages of a high power winch?
The ability to reach sufficient heights in a double-seater even with a
10 kts tailwind.

Bye
Andreas

[Chris Reed]

"Andreas Maurer" > wrote in message
...
> On Thu, 7 Aug 2003 07:52:53 -0600, "Bill Daniels"
> > wrote:
>
>
>
> >The boundary on the high side of acceleration is the tendency of some
> >gliders with high CG's, low hooks and limited down elevator authority to
> >pitch-up uncontrollably when a threshold acceleration is exceeded.
>
> Please tell me the names of these gliders. I have NOT heard of a
> single one yet that showed this behaviour. Not one.
>
In my experience the K8 pitch-up was near uncontrollable when winching. If
you had winched it previously you learnt the theoretically correct
procedure, which was:

a. Stick back to get the nose skid up.

b. Stick central to run on the main wheel; and then

c. (*Immediately the main wheel left the ground) Knuckles hard into the
instrument panel and wait for the pitch to become controllable.

On anything but the softest of take-ups (a) and (b) disappeared, as the
glider was flying before you could react, so the *real* procedure was stick
full forwards as soon as the glider moved.

Once full pitch control was re-established the rest of the launch was fine,
but the first two seconds were only semi-controlled, and that only if you
knew what to expect. I never saw a first flight in the K8 where the pilot
reacted in time to prevent an uncontrolled pitch-up as soon as the main
wheel left the ground. And our winch was not any kind of high-powered
monster.

All the glass gliders I've seen winching behaved well, but the K8 was ...
interesting.

[Bert Willing]

I learnt flying gliders on a Ka7/Ka8 combo (only winching), later
instructing, and I never came across a behaviour of a Ka8 as you describe
it. Completely simple and controlable.

--
Bert Willing

ASW20 "TW"


"Chris Reed" > a écrit dans le message de
...
> "Andreas Maurer" > wrote in message
> ...
> > On Thu, 7 Aug 2003 07:52:53 -0600, "Bill Daniels"
> > > wrote:
> >
> >
> >
> > >The boundary on the high side of acceleration is the tendency of some
> > >gliders with high CG's, low hooks and limited down elevator authority
to
> > >pitch-up uncontrollably when a threshold acceleration is exceeded.
> >
> > Please tell me the names of these gliders. I have NOT heard of a
> > single one yet that showed this behaviour. Not one.
> >
> In my experience the K8 pitch-up was near uncontrollable when winching. If
> you had winched it previously you learnt the theoretically correct
> procedure, which was:
>
> a. Stick back to get the nose skid up.
>
> b. Stick central to run on the main wheel; and then
>
> c. (*Immediately the main wheel left the ground) Knuckles hard into the
> instrument panel and wait for the pitch to become controllable.
>
> On anything but the softest of take-ups (a) and (b) disappeared, as the
> glider was flying before you could react, so the *real* procedure was
stick
> full forwards as soon as the glider moved.
>
> Once full pitch control was re-established the rest of the launch was
fine,
> but the first two seconds were only semi-controlled, and that only if you
> knew what to expect. I never saw a first flight in the K8 where the pilot
> reacted in time to prevent an uncontrolled pitch-up as soon as the main
> wheel left the ground. And our winch was not any kind of high-powered
> monster.
>
> All the glass gliders I've seen winching behaved well, but the K8 was ...
> interesting.
>
>
>
>

[Robert Ehrlich]

Chris Reed wrote:
> ...
> In my experience the K8 pitch-up was near uncontrollable when winching. If
> you had winched it previously you learnt the theoretically correct
> procedure, which was:
>
> a. Stick back to get the nose skid up.
>
> b. Stick central to run on the main wheel; and then
>
> c. (*Immediately the main wheel left the ground) Knuckles hard into the
> instrument panel and wait for the pitch to become controllable.
>

I have no experience with the K8, but the general procedure
I learnt for any glider is: stick full forward *before* start.
I don't know if this will prevent the nose skid of a K8 to lift,
but it doesn't prevent the nose wheel of a K21 to lift. At the
very beginning of the launch, the aerodynamic forces are weak
compared to the inertial forces (accelaration near 1g implies
inertial forces have the same order of magnitude as the weight
of the glider), so when acceleration just begins, the main forces
are the cable traction and the inertial force at CG, making
a pitching up moment. If later the aerodynamic force due to
the elevator becomes sufficient to override this moment, it
is now time to pull the stick avoiding a nose drop.

[Chris Reed]

The K8 in question had a replacement wing from a different glider and some
other repairs - maybe the CG hook was not ideally placed relative to the
revised CG? The glider has now gone, so can't check this out.

"Bert Willing" > wrote in
message ...
> I learnt flying gliders on a Ka7/Ka8 combo (only winching), later
> instructing, and I never came across a behaviour of a Ka8 as you describe
> it. Completely simple and controlable.
>
> --
> Bert Willing
>
> ASW20 "TW"
>
>

[Ray Lovinggood]

I have flown a K8 from a winch launch several dozen
times and never experienced a 'pitch up' as you describe.
I was trained for winch launching on a Ka-7 and then
was moved into the K8. I loved it! The winch, a Tost
unit, I think, was powered by a General Motors V-8
gasoline engine which was mounted on an ancient Mercedes
truck of maybe 5 ton capacity.

The winch was great for launching the single-seaters.
My best altitude at release height was 700 meters
in the K8. The winch could have used a bit more grunt
for launching the Grob 103, but it still managed to
get to 400 meters or so.

Could the weight and balance been out of limits on
the K8 you were launching?

I wish our club had a winch! Then, I would get to
drive the 'Lepo' again!

Ray Lovinggood
Carrboro, North Carolina, USA
LS-1d, 'W8'

At 12:06 11 August 2003, Chris Reed wrote:
>'Andreas Maurer' wrote in message
...
>> On Thu, 7 Aug 2003 07:52:53 -0600, 'Bill Daniels'
>> wrote:
>>
>>
>>
>> >The boundary on the high side of acceleration is the
>>>tendency of some
>> >gliders with high CG's, low hooks and limited down
>>>elevator authority to
>> >pitch-up uncontrollably when a threshold acceleration
>>>is exceeded.
>>
>> Please tell me the names of these gliders. I have
>>NOT heard of a
>> single one yet that showed this behaviour. Not one.
>>
>In my experience the K8 pitch-up was near uncontrollable
>when winching. If
>you had winched it previously you learnt the theoretically
>correct
>procedure, which was:
>
>a. Stick back to get the nose skid up.
>
>b. Stick central to run on the main wheel; and then
>
>c. (*Immediately the main wheel left the ground) Knuckles
>hard into the
>instrument panel and wait for the pitch to become controllable.
>
>On anything but the softest of take-ups (a) and (b)
>disappeared, as the
>glider was flying before you could react, so the *real*
>procedure was stick
>full forwards as soon as the glider moved.
>
>Once full pitch control was re-established the rest
>of the launch was fine,
>but the first two seconds were only semi-controlled,
>and that only if you
>knew what to expect. I never saw a first flight in
>the K8 where the pilot
>reacted in time to prevent an uncontrolled pitch-up
>as soon as the main
>wheel left the ground. And our winch was not any kind
>of high-powered
>monster.
>
>All the glass gliders I've seen winching behaved well,
>but the K8 was ...
>interesting.
>
>
>
>
>

[Bert Willing]

I guess that it was something like this, because Ka8's are somewhat the
reference for very, very easy gliders in all circumstances.
With a glide ratio of almost a PW5.

--
Bert Willing

ASW20 "TW"


"Chris Reed" > a écrit dans le message de
...
> The K8 in question had a replacement wing from a different glider and some
> other repairs - maybe the CG hook was not ideally placed relative to the
> revised CG? The glider has now gone, so can't check this out.
>
> "Bert Willing" > wrote in
> message ...
> > I learnt flying gliders on a Ka7/Ka8 combo (only winching), later
> > instructing, and I never came across a behaviour of a Ka8 as you
describe
> > it. Completely simple and controlable.
> >
> > --
> > Bert Willing
> >
> > ASW20 "TW"
> >
> >
>
>
>

[Ulrich Neumann]

"Chris Reed" > wrote in message >...
> "Andreas Maurer" > wrote in message
> ...
> > On Thu, 7 Aug 2003 07:52:53 -0600, "Bill Daniels"
> > > wrote:
> >
> >
> >
> > >The boundary on the high side of acceleration is the tendency of some
> > >gliders with high CG's, low hooks and limited down elevator authority to
> > >pitch-up uncontrollably when a threshold acceleration is exceeded.
> >
> > Please tell me the names of these gliders. I have NOT heard of a
> > single one yet that showed this behaviour. Not one.
> >
> In my experience the K8 pitch-up was near uncontrollable when winching. If
> you had winched it previously you learnt the theoretically correct
> procedure, which was:
>
> a. Stick back to get the nose skid up.
>
> b. Stick central to run on the main wheel; and then
>
> c. (*Immediately the main wheel left the ground) Knuckles hard into the
> instrument panel and wait for the pitch to become controllable.
>
> On anything but the softest of take-ups (a) and (b) disappeared, as the
> glider was flying before you could react, so the *real* procedure was stick
> full forwards as soon as the glider moved.
>
> Once full pitch control was re-established the rest of the launch was fine,
> but the first two seconds were only semi-controlled, and that only if you
> knew what to expect. I never saw a first flight in the K8 where the pilot
> reacted in time to prevent an uncontrolled pitch-up as soon as the main
> wheel left the ground. And our winch was not any kind of high-powered
> monster.
>
> All the glass gliders I've seen winching behaved well, but the K8 was ...
> interesting.

Chris,

there had to be something wrong with this Ka-8. I soloed on the winch
in a Ka-13 and transitioned to the Ka-8 long before taking up
aero-towing. Unless your winch operator was a graduate of the Naval
Cat-shot school, the launches were very controllable. Our procedure
had us lift off with the stick somewhat forward depending on your
weight and the rudder full left to compensate for the off-center tow
hook. As soon as you lifted off, the rudder went back to neutral (or
wherever it had to go to compensate for cross-wind) and you would
continue in a shallow climb to about 150' before easing the stick back
slightly aft of neutral to assume the steep climb attitude. We would
typically achieve 12-1500' on an average windy day.
Too bad that not more clubs operate winches in the US. Would someone
be able to offer an explanation for this?

Ulrich Neumann
Libelle 'GM'

[Udo Rumpf]

> Too bad that not more clubs operate winches in the US. Would someone
> be able to offer an explanation for this?
>
> Ulrich Neumann
> Libelle 'GM'

It is interesting, that no one has picked up on this.
Every body appears to be concerned about the decline of
member ship and how important it is to get young people into
gliding. Here is a way to substantially reduce the cost in North America,
for young aspiring Glider Pilots.
Regards
Udo

[Ray Lovinggood]

The club, 'DJK' in Landau in der Pfalz, Germany, had
many GREAT winch operators! The only instrument, I
think (hey, this was from 1983 till 1986), was a tach
and maybe a engine coolant temperature gauge. I think
they operated mainly by sight and sound. Yep, they
were great operators! I think their rules stipulated
at least 100 operations with an instructor before they
could operate solo.

Ray Lovinggood
Carrboro, North Carolina, USA
(who misses winch launching in the Land of Aero Tows)

At 13:48 12 August 2003, Bill Daniels wrote:
>Let me add that if the winch driver provides the right
>acceleration, the
>pilot of a K-8, or any similar glider, will be unaware
>of the pitch-up
>tendency. Ray, you were blessed with the services
>of a good winch driver.
>Bill Daniels
>
>'Jonathan Gogan' wrote in message
...
>> Ray;
>> Ka8 well known for pitch-up on winch-launch with
>> lighter (ladies or small/medim men) pilots but still
>>well within W&B
>limits.
>> I have no such problem being f*t g*t but that is not
>>altogether a good
>thing
>> ;-)
>> J.
>>
>>
>> 'Ray Lovinggood' wrote in message
>> ...
>> I have flown a K8 from a winch launch several dozen
>> times and never experienced a 'pitch up' as you describe.
>> I was trained for winch launching on a Ka-7 and then
>> was moved into the K8. I loved it! The winch, a
>>Tost
>> unit, I think, was powered by a General Motors V-8
>> gasoline engine which was mounted on an ancient Mercedes
>> truck of maybe 5 ton capacity.
>>
>> The winch was great for launching the single-seaters.
>> My best altitude at release height was 700 meters
>> in the K8. The winch could have used a bit more grunt
>> for launching the Grob 103, but it still managed to
>> get to 400 meters or so.
>>
>> Could the weight and balance been out of limits on
>> the K8 you were launching?
>>
>> I wish our club had a winch! Then, I would get to
>> drive the 'Lepo' again!
>>
>> Ray Lovinggood
>> Carrboro, North Carolina, USA
>> LS-1d, 'W8'
>>
>> At 12:06 11 August 2003, Chris Reed wrote:
>> >'Andreas Maurer' wrote in message
>> ...
>> >> On Thu, 7 Aug 2003 07:52:53 -0600, 'Bill Daniels'
>> >> wrote:
>> >>
>> >>
>> >>
>> >> >The boundary on the high side of acceleration is
>>>>>the
>> >>>tendency of some
>> >> >gliders with high CG's, low hooks and limited down
>> >>>elevator authority to
>> >> >pitch-up uncontrollably when a threshold acceleration
>> >>>is exceeded.
>> >>
>> >> Please tell me the names of these gliders. I have
>> >>NOT heard of a
>> >> single one yet that showed this behaviour. Not one.
>> >>
>> >In my experience the K8 pitch-up was near uncontrollable
>> >when winching. If
>> >you had winched it previously you learnt the theoretically
>> >correct
>> >procedure, which was:
>> >
>> >a. Stick back to get the nose skid up.
>> >
>> >b. Stick central to run on the main wheel; and then
>> >
>> >c. (*Immediately the main wheel left the ground) Knuckles
>> >hard into the
>> >instrument panel and wait for the pitch to become
>>>controllable.
>> >
>> >On anything but the softest of take-ups (a) and (b)
>> >disappeared, as the
>> >glider was flying before you could react, so the *real*
>> >procedure was stick
>> >full forwards as soon as the glider moved.
>> >
>> >Once full pitch control was re-established the rest
>> >of the launch was fine,
>> >but the first two seconds were only semi-controlled,
>> >and that only if you
>> >knew what to expect. I never saw a first flight in
>> >the K8 where the pilot
>> >reacted in time to prevent an uncontrolled pitch-up
>> >as soon as the main
>> >wheel left the ground. And our winch was not any kind
>> >of high-powered
>> >monster.
>> >
>> >All the glass gliders I've seen winching behaved well,
>> >but the K8 was ...
>> >interesting.
>> >
>> >
>> >
>> >
>> >
>>
>>
>>
>
>

[Bill Daniels]

"Ulrich Neumann" > wrote in message

> Too bad that not more clubs operate winches in the US. Would someone be
able to offer an explanation for this?
>
> Ulrich Neumann
> Libelle 'GM'

This whole thing about uncontrollable pitch-up occurs outside the normal
winch launch profile. It also usually requires a winch with an automatic
transmission in need of service. Mentioning the K-8 as an example of a
glider that pitches up was not intended as a criticism of this fine, docile
glider.

For whatever reason, all gliders are likely to have some acceleration value
above which the launch is not comfortable. This value is almost always
above what is considered "normal" acceleration. All well trained winch
drivers are well aware of this danger.

Most people have at one time or another driven a car with an automatic
transmission that won't start smoothly where the engine revs before the
transmission "thunks" into first gear, jerking the car forward. Should this
happen with a winch, the glider may get snatched into the air before the
pilot has enough down elevator authority to stop the pitch-up. Once an
automobile engine/transmission is installed in a winch, it is difficult to
evaluate the health of the transmission since testing protocols all require
a test drive of the original automobile.

As for why winches are uncommon in the USA, I suspect that it has to do with
the fact that most glider operations in the country are at public airports.
Winching on a public runway that is shared with power traffic is problematic
at best.

There is also the fear of the unknown. Almost all US pilots were trained
with airtow or in powered aircraft and, to them, the sight of a glider in a
45 degree climb near the ground looks like an incredibly dangerous thing.
It's almost impossible to convince them that winch launch is actually as
safe or even safer than airtow.

Bill Daniels

[Bruce Greeff]

I do not understand why winch launch is not popular in the USA.

Its cheap, safe, fast and FUN. Winch launching gliders combines the
rollercoaster first 50 seconds, with all the nice quiet peaceful stuff
for the rest of the flight. Best of both worlds...

Only disadvantage is it needs an extra person on the winch and some
radio co-ordination.


Udo Rumpf wrote:
>>Too bad that not more clubs operate winches in the US. Would someone
>>be able to offer an explanation for this?
>>
>>Ulrich Neumann
>>Libelle 'GM'
>
>
> It is interesting, that no one has picked up on this.
> Every body appears to be concerned about the decline of
> member ship and how important it is to get young people into
> gliding. Here is a way to substantially reduce the cost in North America,
> for young aspiring Glider Pilots.
> Regards
> Udo
>
>

[Marc Ramsey]

"Jeff Goodenough" > wrote...
> Bruce Greeff > wrote:
>
> >Only disadvantage is it needs an extra person on the winch and some
> >radio co-ordination.
>
> As opposed to an extra person in an aircraft in front of you, you mean? :-)

Using aerotow you can launch with two people, one in the tow plane and one in
the glider. Would you do a winch launch with with only the operator and the
pilot?

Marc

[Bob Johnson]

Hi Marc --

Well, granting that a wing-runner can sometimes be dispensed with, and
with good radio connections, I don't see any added safety a ground
observer at the launch end lends to the operation. Of course, this means
that the winch operator also must tow the line back out, and this makes
for a slow operation and one busy fellow, but I don't see why it
couldn't theoretically be done.

Now on car tow, you've got another situation. Here, I believe that
someone looking backward is occaisionally helpful and certainly makes
for more safe.

BJ

Marc Ramsey wrote:
>
> "Jeff Goodenough" > wrote...
> > Bruce Greeff > wrote:
> >
> > >Only disadvantage is it needs an extra person on the winch and some
> > >radio co-ordination.
> >
> > As opposed to an extra person in an aircraft in front of you, you mean? :-)
>
> Using aerotow you can launch with two people, one in the tow plane and one in
> the glider. Would you do a winch launch with with only the operator and the
> pilot?
>
> Marc

[Robin Birch]

Until recently, say 4 years ago, we used reverse pulley with a General
Motors truck pulling in the opposite direction. We may have been the
last club in the UK to use this system, I'm not sure. This had the
disadvantage that the driver didn't know what he was facing until the
glider was flying and he could see the belly view. Because the trucks
were getting old and the only way to operate was to go like blazes until
you knew what you had on the wire it was fairly common for tyro pilots
on the Ka8s to start with a stick fully or fairly forward.

When we got our winch we were all worried that it would be worse.
However, although it initially felt that you were going off a carrier
the initial "jerk" was far less unless the winch driver was a real ham
fisted i****t. This meant that even a Ka8 won't leap into the air unless
you are doing something really daft, a slight bit of forward stick is
all that is required. This is with a winch that is quite capable of
getting an ASH to leap off the deck if you really try. The controls in
most winches, unless totally abused, will give a rapid but controlled
acceleration without too much kick at the start.

Although we do aerotow I must admit that on most average days a winch
launch that will give you 1500 ft in 40secs for say 6 pounds is far
better sense than an aerotow to 2000 for say 30. Also flying a winch
launch is a damn sight easier than an aerotow. (In my humble and
inexperienced opinion).

Robin
--
Robin Birch

[Bill Daniels]

"Bob Johnson" > wrote in message
...
> Hi Marc --
>
> Well, granting that a wing-runner can sometimes be dispensed with, and
> with good radio connections, I don't see any added safety a ground
> observer at the launch end lends to the operation. Of course, this means
> that the winch operator also must tow the line back out, and this makes
> for a slow operation and one busy fellow, but I don't see why it
> couldn't theoretically be done.
>
> Now on car tow, you've got another situation. Here, I believe that
> someone looking backward is occaisionally helpful and certainly makes
> for more safe.
>
> BJ

I'm a bit uncomfortable with the idea of a wing runner-less winch takeoff.
CG hooks don't pull the glider straight so if the wing catches on something,
the resulting ground loop will be very violent. Then there's the problem of
properly clearing the airspace above and behind the glider before committing
to the launch.

On the other hand, using the winch driver to pull out the cable works fine
if the driver is amenable and the pull-out drag brake is reliable. The
worry here is that if the winch uses an automatic transmission, the engine
must be left running for the tranny to get lubrication. If the transmission
gets vibrated into gear......things get complicated. For this reason, it
makes sense to have a way to completely disengage the winch drum from the
transmission so the engine can be shut down during the cable pull-out. It's
safer and it saves a lot of fuel.

Bill Daniels

[Mark James Boyd]

I would love to find a winch in California, but haven't
heard of any in this state. I'd love to learn this type
of launch (or auto-tow).

It seems it isn't as popular as aerotow for a lot of reasons.
Winches can't do retrieves/landouts, can't tow to 8000 ft
for sightseeing flights on calm days, require more runway
(we only have 3000ft) for altitude, are more difficult
to move to a new location (for a meet or gathering), and
winches mean there is a long rope falling out of the
sky somewhere after release. Of course the benefit is that
the complexity of a towplane and qualified pilot are
avoided.

At least these were some of the reasons discussed when
I asked about ground launch here at Avenal.

But one would think that auto-tow would be more popular.
One can certainly drive easily somewhere, and if the
thing can haul a trailer, it might tow up a glider?

Is there anywhere in California that does auto-tow or
winch? It would be a kick to try it. Also, who sells
equipment (like a hitch/pulley) for auto tow?

[Bill Daniels]

"Mark James Boyd" > wrote in message
...
> I would love to find a winch in California, but haven't
> heard of any in this state. I'd love to learn this type
> of launch (or auto-tow).
>
> It seems it isn't as popular as aerotow for a lot of reasons.
> Winches can't do retrieves/landouts, can't tow to 8000 ft
> for sightseeing flights on calm days, require more runway
> (we only have 3000ft) for altitude, are more difficult
> to move to a new location (for a meet or gathering), and
> winches mean there is a long rope falling out of the
> sky somewhere after release. Of course the benefit is that
> the complexity of a towplane and qualified pilot are
> avoided.
>
> At least these were some of the reasons discussed when
> I asked about ground launch here at Avenal.
>
> But one would think that auto-tow would be more popular.
> One can certainly drive easily somewhere, and if the
> thing can haul a trailer, it might tow up a glider?
>
> Is there anywhere in California that does auto-tow or
> winch? It would be a kick to try it. Also, who sells
> equipment (like a hitch/pulley) for auto tow?
>
>
When I lived in SoCal in the 1960's a lot of folks auto towed regularly on
Mojave dry lakes. If you have lots of room, as on the dry lakes, auto tow
is great.

Bill Daniels

[Clint]

> On the other hand, using the winch driver to pull out the cable works fine
> if the driver is amenable and the pull-out drag brake is reliable. The
> worry here is that if the winch uses an automatic transmission, the engine
> must be left running for the tranny to get lubrication. If the transmission
> gets vibrated into gear......things get complicated. For this reason, it
> makes sense to have a way to completely disengage the winch drum from the
> transmission so the engine can be shut down during the cable pull-out. It's
> safer and it saves a lot of fuel.
>
> Bill Daniels

The winch we use has a V8 engine driving through a three speed
automatic gearbox. There are two drums connected to the differential.
The drums have to be able to dissengage from the drive shafts or both
drums would turn at the same time - and we only launch one glider at a
time. Thus when pulling the cables out - both drums rotate freely and
the transmission does not turn. There are simple brakes on the drums
to prevent overun whilst pulling the cables out.

The winch driver can pull the cables back - but it is faster if there
is a dedicated person to do it. We use thus a winch driver, tractor
driver, signal man (we use a light to give signals to the winch) and a
wing runner. This can be reduced to a winch driver (who also pulls the
cable) and a wing runner who also gives the signals (wing signals as
opposed to the light - or with a handheld radio). It will be
unadvisable to elliminate the wing runner as he keeps a lookout for
other traffic which the pilot cannot see - and hooks up the glider
when the pilot has completed all his other pre-takoff checks. You
would not want a glider hooked up to a winch if the pilot is not ready
to release instantly.

Last Saturday - I got a 610m (1800ft)launch from a 4800ft cable in an
ASK 21. There was a 30km hour wind straight down the runway. What a
rush! 400m is what we normally achieve in the ASK 21 as it is a heavy
glider.

Clinton
LAK 12

[Bert Willing]

Well, it does work without a wingrunner, supposed that you put the wingtip
on a chair or something like this. Breaks on 'til the slack is taken up, and
then a decent acceleration by the winch.

--
Bert Willing

ASW20 "TW"


"Bill Daniels" > a écrit dans le message de
...
>
> "Bob Johnson" > wrote in message
> ...
> > Hi Marc --
> >
> > Well, granting that a wing-runner can sometimes be dispensed with, and
> > with good radio connections, I don't see any added safety a ground
> > observer at the launch end lends to the operation. Of course, this means
> > that the winch operator also must tow the line back out, and this makes
> > for a slow operation and one busy fellow, but I don't see why it
> > couldn't theoretically be done.
> >
> > Now on car tow, you've got another situation. Here, I believe that
> > someone looking backward is occaisionally helpful and certainly makes
> > for more safe.
> >
> > BJ
>
> I'm a bit uncomfortable with the idea of a wing runner-less winch takeoff.
> CG hooks don't pull the glider straight so if the wing catches on
something,
> the resulting ground loop will be very violent. Then there's the problem
of
> properly clearing the airspace above and behind the glider before
committing
> to the launch.
>
> On the other hand, using the winch driver to pull out the cable works fine
> if the driver is amenable and the pull-out drag brake is reliable. The
> worry here is that if the winch uses an automatic transmission, the engine
> must be left running for the tranny to get lubrication. If the
transmission
> gets vibrated into gear......things get complicated. For this reason, it
> makes sense to have a way to completely disengage the winch drum from the
> transmission so the engine can be shut down during the cable pull-out.
It's
> safer and it saves a lot of fuel.
>
> Bill Daniels
>

[Ian Johnston]

On Tue, 12 Aug 2003 14:46:22 UTC, Ray Lovinggood
> wrote:

: The only instrument, I
: think (hey, this was from 1983 till 1986), was a tach
: and maybe a engine coolant temperature gauge. I think
: they operated mainly by sight and sound.

When I was a winch instructor at a club in the southwest of England I
always taught new drivers to do it by the appearance of the glider and
the bow in the cable alone. Of necessity, because there were no engine
gauges at all, but I firmly believe it's the only way to do it well.
It's also very helpful, I think, if winch drivers are also current
glider pilots.

Ian
--

[F.L. Whiteley]

Don't know about leaving a chair on the airfield, but an orange traffic cone
perhaps, and keep the grass mowed short. Hopefully, there's enough interest
so that it doesn't come to this in the first place.

Frank Whiteley

"Bert Willing" > wrote in
message ...
> Well, it does work without a wingrunner, supposed that you put the wingtip
> on a chair or something like this. Breaks on 'til the slack is taken up,
and
> then a decent acceleration by the winch.
>
> --
> Bert Willing
>
> ASW20 "TW"
>
>
> "Bill Daniels" > a écrit dans le message de
> ...
> >
> > "Bob Johnson" > wrote in message
> > ...
> > > Hi Marc --
> > >
> > > Well, granting that a wing-runner can sometimes be dispensed with, and
> > > with good radio connections, I don't see any added safety a ground
> > > observer at the launch end lends to the operation. Of course, this
means
> > > that the winch operator also must tow the line back out, and this
makes
> > > for a slow operation and one busy fellow, but I don't see why it
> > > couldn't theoretically be done.
> > >
> > > Now on car tow, you've got another situation. Here, I believe that
> > > someone looking backward is occaisionally helpful and certainly makes
> > > for more safe.
> > >
> > > BJ
> >
> > I'm a bit uncomfortable with the idea of a wing runner-less winch
takeoff.
> > CG hooks don't pull the glider straight so if the wing catches on
> something,
> > the resulting ground loop will be very violent. Then there's the
problem
> of
> > properly clearing the airspace above and behind the glider before
> committing
> > to the launch.
> >
> > On the other hand, using the winch driver to pull out the cable works
fine
> > if the driver is amenable and the pull-out drag brake is reliable. The
> > worry here is that if the winch uses an automatic transmission, the
engine
> > must be left running for the tranny to get lubrication. If the
> transmission
> > gets vibrated into gear......things get complicated. For this reason,
it
> > makes sense to have a way to completely disengage the winch drum from
the
> > transmission so the engine can be shut down during the cable pull-out.
> It's
> > safer and it saves a lot of fuel.
> >
> > Bill Daniels
> >
>
>

[Bill Daniels]

I was shown a gadget just for this sort of thing made of PVC pipe. It was
essentially a tripod with a 2 meter horizontal pipe along which the wing
would slide as the glider started its roll. It was intended for airtow but
the thing would work with a winch.

I agree with Frank. I hope it doesn't come to this.

Returning to the USA situation with winch launch for a moment, whenever a
group tries a once-a-year winch party with 20 or so untrained people, the
result looks a lot like a Chinese fire drill. Since this is the usual
situation in the US, there is the widespread opinion that winch launching is
a confused, labor intensive affair.

However, a group of experienced winch people with polished procedures can
make it look as easy as air tow. It sure is a lot quieter, cleaner and more
pleasant than the noisy, dusty environment in the vicinity of a tug.

Bill Daniels

"F.L. Whiteley" > wrote in message
...
> Don't know about leaving a chair on the airfield, but an orange traffic
cone
> perhaps, and keep the grass mowed short. Hopefully, there's enough
interest
> so that it doesn't come to this in the first place.
>
> Frank Whiteley
>
> "Bert Willing" > wrote in
> message ...
> > Well, it does work without a wingrunner, supposed that you put the
wingtip
> > on a chair or something like this. Breaks on 'til the slack is taken up,
> and
> > then a decent acceleration by the winch.
> >
> > --
> > Bert Willing
> >
> > ASW20 "TW"

[Tim]

"Bill Daniels" >s comments read:

> I was shown a gadget just for this sort of thing made of PVC pipe. It was
>essentially a tripod with a 2 meter horizontal pipe along which the wing
>would slide as the glider started its roll. It was intended for airtow but
>the thing would work with a winch.

Surely this situation normally occurs when retrieving as well as days
when the operation is normally closed. I've heard a tale about a coke
can and good blast of prop wash being used to get the wind up. Sounds
like asking for trouble ...

--
Tim - ASW20CL "20"

[Mike Lindsay]

In article >, Bill Daniels
> writes
>
>I agree with Frank. I hope it doesn't come to this.
>
>Returning to the USA situation with winch launch for a moment, whenever a
>group tries a once-a-year winch party with 20 or so untrained people, the
>result looks a lot like a Chinese fire drill. Since this is the usual
>situation in the US, there is the widespread opinion that winch launching is
>a confused, labor intensive affair.
>
>However, a group of experienced winch people with polished procedures can
>make it look as easy as air tow. It sure is a lot quieter, cleaner and more
>pleasant than the noisy, dusty environment in the vicinity of a tug.
>
>Bill Daniels
It can also be very efficient. The Midland Gliding Club which operates
from a hill top site in Shropshire, England, uses a single drum winch
to launch and a lower powered winch to retrieve the cable. The launch
rate can be phenomenal!

--
Mike Lindsay

[Jonathan Gogan]

yeee-hah (cable-please-don't-break), yeee-hah
J.

"OscarCVox" > wrote in message
...
Gliders susceptable to this often have features in common.
Light weight
High mounted wings
nose wheel or skid
The whole thing made worse by inexpert winch drivers in a powerfull winch
used
to launching heavy 2 seaters

The worst experience I have ever had was in one of those PW5 things. It
rotated
until the wheel on the tail hit the ground hard then took off like a scalded
cat. With full forward stick I was about 200ft before I managed to resume
control. Scary.
With a nose wheel or skid they rock back on the all out signal presenting
the
wings at a large angle of attack before the elevator has a chance to become
effective.

[Robert Ehrlich]

Mike Lindsay wrote:
>
> It can also be very efficient. The Midland Gliding Club which operates
> from a hill top site in Shropshire, England, uses a single drum winch
> to launch and a lower powered winch to retrieve the cable. The launch
> rate can be phenomenal!
>

How does the retrieve work? I.e. is that not a way of moving
the problem to how to get back the retrieve cable, or does
it remain tied to the main cable? In this case doesn'it
slow down and pull back the main cable?

[Robert Ehrlich]

OscarCVox wrote:
>
> Gliders susceptable to this often have features in common.
> Light weight
> High mounted wings
> nose wheel or skid
> The whole thing made worse by inexpert winch drivers in a powerfull winch used
> to launching heavy 2 seaters
>
> The worst experience I have ever had was in one of those PW5 things. It rotated
> until the wheel on the tail hit the ground hard then took off like a scalded
> cat. With full forward stick I was about 200ft before I managed to resume
> control. Scary.
> With a nose wheel or skid they rock back on the all out signal presenting the
> wings at a large angle of attack before the elevator has a chance to become
> effective.

I think the most important factors in the cas of the PW5 are the
high position of the tail skid, allowing for a high pitchup before
leaving the ground, and a to aft position of the CG hook. The ASK23
is also a light weight glider with high mounted wings and a nose
wheel, but it doesn't exhibit this behavior.

[Bill Daniels]

The lighter Spectra doesn't sag nearly as much as steel so the pull vector
is more nearly aligned with the flight path. The potential height gain at
release is more due to the angle that Spectra pulls on the glider.

The Van Gelder? You bet. That's the reference winch design. Somebody want
to link us to some detailed pictures of the Van Gelder?

Bill Daniels

"Bob Johnson" > wrote in message
...
> Robert --
>
> There's only about a 100 lb reduction in line weight at release,
> assuming you're currently using 5mm steel, so I wouldn't expect a
> dramatic height gain.
>
> Hoo boy, a 6 drum Diesel Monster Van Gelder -- now THAT'S a winch!!
>
> Robert Johnson 8')
>
>
> Robert John wrote:
> >
> > At Dunstable (London Gliding Club - UK) we have 4 tugs
> > (typically 2 operating unless it's really busy) and
> > a 6 drum diesel Munster Van Gelder winch. The launch
> > rates with a slick ground crew can be extremely good.
> > 30 secs to launch, another 30secs to reel in the cable,
> > then hook up the next one and go.
> >
> > It's quick, quiet and cheap (a quarter the cost of
> > a typical tug launch).
> >
> > Our only bugbear is that the field is fairly short
> > so we rarely see more than 1200 feet from a winch launch,
> > sometimes as little as 800 (flat calm on one of the
> > shorter runs). 1500'+ would make winching the preferred
> > method of launch for most XC flights (standard aerotow
> > is 2000ft - we Brits are used to thermalling up from
> > heights most Americans would regard as circuit height!).
> >
> >
> > Perhaps we should experiment with Plasma rope?
> >
> > The winch is slightly less labour-intensive than the
> > tug in that the hook-on and control crew is the same
> > for both but you only need one winch driver and he
> > is utilised as soon as he is needed - you don't need
> > to wait for him to return to earth and taxi into position
> > after a launch. Someone from the launch point goes
> > to the winch with a tractor and 6-hook trailer before
> > the last cable is used so as to be ready to bring the
> > cables back to the launch point.
> >
> > Rob John
> >
> > At 08:24 14 August 2003, Mike Lindsay wrote:
> > >In article , Bill Daniels
> > > writes
> > >>
> > >>I agree with Frank. I hope it doesn't come to this.
> > >>
> > >>Returning to the USA situation with winch launch for
> > >>a moment, whenever a
> > >>group tries a once-a-year winch party with 20 or so
> > >>untrained people, the
> > >>result looks a lot like a Chinese fire drill. Since
> > >>this is the usual
> > >>situation in the US, there is the widespread opinion
> > >>that winch launching is
> > >>a confused, labor intensive affair.
> > >>
> > >>However, a group of experienced winch people with polished
> > >>procedures can
> > >>make it look as easy as air tow. It sure is a lot
> > >>quieter, cleaner and more
> > >>pleasant than the noisy, dusty environment in the vicinity
> > >>of a tug.
> > >>
> > >>Bill Daniels
> > >It can also be very efficient. The Midland Gliding
> > >Club which operates
> > >from a hill top site in Shropshire, England, uses a
> > > single drum winch
> > >to launch and a lower powered winch to retrieve the
> > >cable. The launch
> > >rate can be phenomenal!
> > >
> > >--
> > >Mike Lindsay
> > >

[W.J. \(Bill\) Dean \(U.K.\).]

The main cable and the retrieve cable are both shackled to a "triangle", the
rope trace to the glider is attached to the third corner. No parachute is
used, the whole thing drops straight down when released.

This system can only be used when it is safe and operationally convenient
for the cable, triangle and retrieve cable to drop straight down when
released, without risk of damage to people or property, and without damaging
itself.

If you go to the on-line "Gliding Magazine" photo section, page 4, 4/3/2003
http://www.glidingmagazine.com/PhotoGallery.asp?Page=4 you will see 3 photos
I posted of a K21 being launched at the Mynd.

In the first photo the triangle is about to leave the ground, the retrieve
cable is on the ground in the right foreground.

In the second photo the triangle is the black object at the end of the rope
trace, the wire cable and retrieve cable cannot be seen. The winch is just
below the skyline right center well clear of the trees.

The third photo was in fact taken first, it shows the glider ready to
launch.
The first part of the trace is the weak link unit, a short wire trace in
coloured (black) hose, you can see a blue link unit (used for most single
seaters) under the wing tip.

Since we never launch without the retrieve wire attached, it is difficult to
know if we are losing height. However, we are saving the drag of the chute
used in most other systems. We are well pleased with the height we get.

W.J. (Bill) Dean (U.K.) - member of Midland G.C.
Remove "ic" to reply.

>
> "Robert Ehrlich" > wrote in message
> ...
>
> >
> > Mike Lindsay wrote:
> >
> > It can also be very efficient. The Midland Gliding Club which operates
> > from a hill top site in Shropshire, England, uses a single drum winch
> > to launch and a lower powered winch to retrieve the cable. The launch
> > rate can be phenomenal!
> >
>
> How does the retrieve work? I.e. is that not a way of moving
> the problem to how to get back the retrieve cable, or does
> it remain tied to the main cable? In this case doesn'it
> slow down and pull back the main cable?
>

[Bob Johnson]

<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
I don't know about detailed --
<p><A HREF="http://www.621vgs.co.uk/works.htm">http://www.621vgs.co.uk/works.htm</A>
<p>Bill Daniels wrote:
<blockquote TYPE=CITE>The lighter Spectra doesn't sag nearly as much as
steel so the pull vector
<br>is more nearly aligned with the flight path.&nbsp; The potential height
gain at
<br>release is more due to the angle that Spectra pulls on the glider.
<p>The Van Gelder? You bet.&nbsp; That's the reference winch design.&nbsp;
Somebody want
<br>to link us to some detailed pictures of the Van Gelder?
<p>Bill Daniels
<p>"Bob Johnson" > wrote in message
<br><a </a>...
<br>> Robert --
<br>>
<br>> There's only about a 100 lb reduction in line weight at release,
<br>> assuming you're currently using 5mm steel, so I wouldn't expect a
<br>> dramatic height gain.
<br>>
<br>> Hoo boy, a 6 drum Diesel Monster Van Gelder -- now THAT'S a winch!!
<br>>
<br>> Robert Johnson 8')
<br>>
<br>>
<br>> Robert John wrote:
<br>> >
<br>> > At Dunstable (London Gliding Club - UK) we have 4 tugs
<br>> > (typically 2 operating unless it's really busy) and
<br>> > a 6 drum diesel Munster Van Gelder winch.&nbsp; The launch
<br>> > rates with a slick ground crew can be extremely good.
<br>> >&nbsp; 30 secs to launch, another 30secs to reel in the cable,
<br>> > then hook up the next one and go.
<br>> >
<br>> > It's quick, quiet and cheap (a quarter the cost of
<br>> > a typical tug launch).
<br>> >
<br>> > Our only bugbear is that the field is fairly short
<br>> > so we rarely see more than 1200 feet from a winch launch,
<br>> > sometimes as little as 800 (flat calm on one of the
<br>> > shorter runs).&nbsp; 1500'+ would make winching the preferred
<br>> > method of launch for most XC flights (standard aerotow
<br>> > is 2000ft - we Brits are used to thermalling up from
<br>> > heights most Americans would regard as circuit height!).
<br>> >
<br>> >
<br>> > Perhaps we should experiment with Plasma rope?
<br>> >
<br>> > The winch is slightly less labour-intensive than the
<br>> > tug in that the hook-on and control crew is the same
<br>> > for both but you only need one winch driver and he
<br>> > is utilised as soon as he is needed - you don't need
<br>> > to wait for him to return to earth and taxi into position
<br>> > after a launch.&nbsp;&nbsp; Someone from the launch point goes
<br>> > to the winch with a tractor and 6-hook trailer before
<br>> > the last cable is used so as to be ready to bring the
<br>> > cables back to the launch point.
<br>> >
<br>> > Rob John
<br>> >
<br>> > At 08:24 14 August 2003, Mike Lindsay wrote:
<br>> > >In article , Bill Daniels
<br>> > > writes
<br>> > >>
<br>> > >>I agree with Frank.&nbsp; I hope it doesn't come to this.
<br>> > >>
<br>> > >>Returning to the USA situation with winch launch for
<br>> > >>a moment, whenever a
<br>> > >>group tries a once-a-year winch party with 20 or so
<br>> > >>untrained people, the
<br>> > >>result looks a lot like a Chinese fire drill.&nbsp; Since
<br>> > >>this is the usual
<br>> > >>situation in the US, there is the widespread opinion
<br>> > >>that winch launching is
<br>> > >>a confused, labor intensive affair.
<br>> > >>
<br>> > >>However, a group of experienced winch people with polished
<br>> > >>procedures can
<br>> > >>make it look as easy as air tow.&nbsp; It sure is a lot
<br>> > >>quieter, cleaner and more
<br>> > >>pleasant than the noisy, dusty environment in the vicinity
<br>> > >>of a tug.
<br>> > >>
<br>> > >>Bill Daniels
<br>> > >It can also be very efficient. The Midland Gliding
<br>> > >Club which operates
<br>> > >from a hill top site in Shropshire, England, uses a
<br>> > > single drum winch
<br>> > >to launch and a lower powered winch to retrieve the
<br>> > >cable. The launch
<br>> > >rate can be phenomenal!
<br>> > >
<br>> > >--
<br>> > >Mike Lindsay
<br>> > ></blockquote>
</html>

[W.J. \(Bill\) Dean \(U.K.\).]

The Van Gelder was a superb winch when it first arrived in the U.K., but the reference winch today is the Skylaunch http://www.skylaunchuk.com/ . I have done many launches in solo gliders and in two-seaters by both winches, and I prefer the Skylaunch. I have no commercial interest in that company.

The reference you gave is to 621VGS, which is an Air Training Corps squadron, and therefore part of the Royal Air Force. Their equipment is bought and maintained by the taxpayer, and their economics are rather different from the civilian clubs.

Note that the Van Gelder needs a substantial vehicle to tow it, the Skylaunch can be towed on the road by any reasonable SUV. The Midland Gliding Club have a Skylaunch which is towed round our rough airfield by a Range Rover.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.
"Bob Johnson" > wrote in message
...

I don't know about detailed --
http://www.621vgs.co.uk/works.htm

Bill Daniels wrote:

The lighter Spectra doesn't sag nearly as much as steel so the pull vector
is more nearly aligned with the flight path. The potential height gain at
release is more due to the angle that Spectra pulls on the glider.
The Van Gelder? You bet. That's the reference winch design. Somebody want
to link us to some detailed pictures of the Van Gelder?

Bill Daniels

> "Bob Johnson" > wrote in message ...
> Robert --
>
> There's only about a 100 lb reduction in line weight at release,
> assuming you're currently using 5mm steel, so I wouldn't expect a
> dramatic height gain.
>
> Hoo boy, a 6 drum Diesel Monster Van Gelder -- now THAT'S a winch!!
>
> Robert Johnson 8')
>
> >
> > Robert John wrote:
> >
> > At Dunstable (London Gliding Club - UK) we have 4 tugs
> > (typically 2 operating unless it's really busy) and
> > a 6 drum diesel Munster Van Gelder winch. The launch
> > rates with a slick ground crew can be extremely good.
> > 30 secs to launch, another 30secs to reel in the cable,
> > then hook up the next one and go.
> >
> > It's quick, quiet and cheap (a quarter the cost of
> > a typical tug launch).
> >
> > Our only bugbear is that the field is fairly short
> > so we rarely see more than 1200 feet from a winch launch,
> > sometimes as little as 800 (flat calm on one of the
> > shorter runs). 1500'+ would make winching the preferred
> > method of launch for most XC flights (standard aerotow
> > is 2000ft - we Brits are used to thermalling up from
> > heights most Americans would regard as circuit height!).
> >
> >
> > Perhaps we should experiment with Plasma rope?
> >
> > The winch is slightly less labour-intensive than the
> > tug in that the hook-on and control crew is the same
> > for both but you only need one winch driver and he
> > is utilised as soon as he is needed - you don't need
> > to wait for him to return to earth and taxi into position
> > after a launch. Someone from the launch point goes
> > to the winch with a tractor and 6-hook trailer before
> > the last cable is used so as to be ready to bring the
> > cables back to the launch point.
> >
> > Rob John
> >

[Bill Daniels]

"W.J. (Bill) Dean (U.K.)." > wrote in message ...
The Van Gelder was a superb winch when it first arrived in the U.K., but the reference winch today is the Skylaunch http://www.skylaunchuk.com/ . I have done many launches in solo gliders and in two-seaters by both winches, and I prefer the Skylaunch. I have no commercial interest in that company.

The reference you gave is to 621VGS, which is an Air Training Corps squadron, and therefore part of the Royal Air Force. Their equipment is bought and maintained by the taxpayer, and their economics are rather different from the civilian clubs.

Note that the Van Gelder needs a substantial vehicle to tow it, the Skylaunch can be towed on the road by any reasonable SUV. The Midland Gliding Club have a Skylaunch which is towed round our rough airfield by a Range Rover.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

Bill, would you expand on the reasons for your preference for the Skylaunch winch?

Aren't most of the Van Gelder winches mounted on trucks so the towing issue is moot?

Bill Daniels

[Bob Johnson]

Bill, I appreciate the lead. Given the relatively high initial cost,
operating cost, and manning problems for a decent tug, 19,000 USD for a
new first-class winch doesn't seem unreasonable, particularly since they
can go for years with mostly only fuel cost to consider. And since
practically any club member can be quickly taught to drive a well
thought out winch, it's a wonder they are not more popular. I see that
Skylaunch has chosen to follow Craig's example in choosing the big-block
GM V-8 engine 8') while Supacat is sticking with the 250 hp Diesel.

We were hoping for the magic 2000-ft light wind launch height. Given our
5000 ft runway length, Plasma rope and a 20 kt wind, we may make it yet.
What fraction of the runway length in launch height are you getting with
these high powered winches?

Thanks and best regards,

Bob Johnson

[Bruce Greeff]

Hi Bob

Depending on the aircraft 2000' launch is a very reasonable height
expectation for a good day.

We have 1800m of runway / steel cable. (approx 5900')
Runway is 4740' MSL
Density altitude is regularly above 9000' (it gets hot here, even in winter)
Launch in still air is around 1/3 of cable length.
In calm conditions we get

- 1400' -1600' dual in a trainer.
- 1600' -1800' solo in a 15m (Cirrus)
- 1600' + solo in a 17m

When the wind is down the runway and over 10kt the launch heights
improve dramatically. Personal best is 2300' in solo in one of the
trainers into a 20Kt wind. This thing is flying within 10m under those
conditions and pulling up at minimum safe winch speed makes a big
difference.

This is achieved with what can most kindly be described as a tired
winch. It is fifteen years old homebuilt job, with a Ford 352 Windsor
engine connected to a three speed auto transmission. We launch in second
gear to control the take up and prevent those big moments this thread
started on. We also seldom use the full (nominally 220hp) power
available, only the heavier two seaters need more power.

So the caption goes, vast power is no requirement - we don't have it.
You also don't NEED plasma, though we would love to replace our steel
wire for the convenience of plasma. Lots of reliable torque and a decent
run of cable do the trick, as long as the pilots and winch driver know
their stuff.

As for the cost - the winch will probably be the best investment a club
ever makes. Ours has had minimal maintenance, never been overhauled and
still works adequately although it is getting due for an upgrade. Our
club has been sending pilots solo on this winch for 10 years - over
15,000 launches, no injuries. If we had been aerotowing the club would
have folded financially years ago. Because it is cheap we do a lot of
flying on marginal days and the club stays active, and members stay current.

Bob Johnson wrote:
> Bill, I appreciate the lead. Given the relatively high initial cost,
> operating cost, and manning problems for a decent tug, 19,000 USD for a
> new first-class winch doesn't seem unreasonable, particularly since they
> can go for years with mostly only fuel cost to consider. And since
> practically any club member can be quickly taught to drive a well
> thought out winch, it's a wonder they are not more popular. I see that
> Skylaunch has chosen to follow Craig's example in choosing the big-block
> GM V-8 engine 8') while Supacat is sticking with the 250 hp Diesel.
>
> We were hoping for the magic 2000-ft light wind launch height. Given our
> 5000 ft runway length, Plasma rope and a 20 kt wind, we may make it yet.
> What fraction of the runway length in launch height are you getting with
> these high powered winches?
>
> Thanks and best regards,
>
> Bob Johnson

[W.J. \(Bill\) Dean \(U.K.\).]

The Van Gelder http://www.proximedia.com/local/netherlands/m/machine-el/various.htm is built in units of 2, 4, 6, or 8 drums and can be on a truck or as a trailer.

I have not seen the version mounted on a truck, all the ones I have seen were trailers and were 6 drum; this includes the one at Dunstable with which I have had many launches.

If you have a winch mounted on a truck (I have seen other winches on a truck, e.g. the Tost winches at Lasham) then you have to buy a truck as well, and if the truck has problems or needs work then the winch is out of service as well. Winch maintenance when on a truck tends to be more difficult because access is more difficult.

I think the best layout is a trailer winch which can be towed on the public road and on the field by any decent SUV or reasonably sized car. The Skylaunch has done a demonstration tour of Germany like this, the trailer Van Gelder and the Supercat would have to go on a low loader truck or be towed by a large vehicle. Note that the Air Training Corps http://www.621vgs.co.uk/works.htm use a Bedford 4 Tonner (probably 4-wheel drive), all very well for them, the taxpayer pays for it!

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.
"Bill Daniels" > wrote in message ...

"W.J. (Bill) Dean (U.K.)." > wrote in message ...
The Van Gelder was a superb winch when it first arrived in the U.K., but the reference winch today is the Skylaunch http://www.skylaunchuk.com/ . I have done many launches in solo gliders and in two-seaters by both winches, and I prefer the Skylaunch. I have no commercial interest in that company.

The reference you gave is to 621VGS, which is an Air Training Corps squadron, and therefore part of the Royal Air Force. Their equipment is bought and maintained by the taxpayer, and their economics are rather different from the civilian clubs.

Note that the Van Gelder needs a substantial vehicle to tow it, the Skylaunch can be towed on the road by any reasonable SUV. The Midland Gliding Club have a Skylaunch which is towed round our rough airfield by a Range Rover.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

Bill, would you expand on the reasons for your preference for the Skylaunch winch?

Aren't most of the Van Gelder winches mounted on trucks so the towing issue is moot?

Bill Daniels

[W.J. \(Bill\) Dean \(U.K.\).]

I understand that Supercat http://www.supacat.com/ have not in fact built
any new winches for some 10 years. The company still trades but is busy
with other products.

See the article by Gordon Peters on the on-line Gliding & Motorgliding
International site,
http://www.glidingmagazine.com/ListFeatureArticleDtl.asp?id=345 . His club
is the one where the Clayton winch originated in the late 50s or early 60s,
and the Supercat is a development of it. Remember that the original layout
of the design, still seen in the Supercat, was done to work with piano wire
(single strand) as distinct from stranded wire. The Tost, Van Gelder and
Skylaunch winches would almost certainly fail with piano wire, but this does
not matter because nobody uses it any more.

Big V-8 engines from the USA, petrol (gasoline) converted to run on Propane,
are now the engine of choice for winches in the U.K. I understand that the
engines used in the Skylaunch are the marine versions. They are of course
fitted with the usual automotive automatic transmission, I don't know if
these are modified for winching.

These engines have been in use in the U.K. for many years, for instance in
Tost winches of which there are a number here. The special features of the
Skylaunch are the detail design, and in particular the power control and the
ease of driving.

I think that when the quality of winch driving is less than perfect it is
due to one or more of the following factors:
1/ Bad driving.
2/ A winch that is difficult to drive.
3/ Difficult conditions.
For instance, one site I know has trees on the borders, so whenever there is
any wind there is marked turbulence and gradient just at the height where
the glider is rotating into the full climb.
It is easier to drive the Skylaunch well compared with other types of winch.

I do not know how the heights we get at the Mynd http://www.longmynd.com/
compare to the length available. We tend to be reasonably conservative in
our driving and flying methods, that is we leave a bit in hand. We
practically never break weak links, and we try to fly some way from the edge
in rotating into the full climb. Sites with restricted runs sometimes have
to try harder.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

>
> "Bob Johnson" > wrote in message
> ...
>
> Bill, I appreciate the lead. Given the relatively high initial cost,
> operating cost, and manning problems for a decent tug, 19,000 USD for a
> new first-class winch doesn't seem unreasonable, particularly since they
> can go for years with mostly only fuel cost to consider. And since
> practically any club member can be quickly taught to drive a well
> thought out winch, it's a wonder they are not more popular. I see that
> Skylaunch has chosen to follow Craig's example in choosing the big-block
> GM V-8 engine 8') while Supacat is sticking with the 250 hp Diesel.
>
> We were hoping for the magic 2000-ft light wind launch height. Given our
> 5000 ft runway length, Plasma rope and a 20 kt wind, we may make it yet.
> What fraction of the runway length in launch height are you getting with
> these high powered winches?
>
> Thanks and best regards,
>
> Bob Johnson.
>

[W.J. \(Bill\) Dean \(U.K.\).]

It is not unknown for the biggest and busiest clubs to do 15,000 winch
launches per annum.

Usually at these clubs both the driving and the maintenance are done by
employees. It costs so much if the winch is mechanically unreliable, the
driving is of low quality, or the launch rate is poor.

The better clubs have worked this out. This is why they are prepared to
pay for good production winches, good drivers, good maintenance and to
change the cable before it is worn out.

Compare the value of the gliders waiting for a launch with the value of the
equipment doing the launching.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

>
> "Bruce Greeff" > wrote in message
> ...
>
> Hi Bob
>
< snip >
>
> As for the cost - the winch will probably be the best investment a club
> ever makes. Ours has had minimal maintenance, never been overhauled and
> still works adequately although it is getting due for an upgrade. Our
> club has been sending pilots solo on this winch for 10 years - over
> 15,000 launches, no injuries. If we had been aerotowing the club would
> have folded financially years ago. Because it is cheap we do a lot of
> flying on marginal days and the club stays active, and members stay
> current.
>

[Bert Willing]

On a glider only site you would be in the very vicinity of the pattern. It
is obvious that if there are many gliders at this altitude, you need to
think about what you do.

On a site shared with power traffic, patterns are usually seperated, i.e.
gliders on left hand pattern, power on right hand pattern, and there are
restrictions as to thermalling on final approach.

Just for completeness, these 800-1200ft release altitudes relate to fields
which provide something like 3000ft ish cable length.

With my Calif on a 5000ft cable, I typically get 1800-2000ft release
altitude. I'm not convinced that a Plasma rope would get you much higher -
there is nothing like length of the cable to increase height, and recent
tests on a military airfield in France have shown that there is no
saturation to be seen at 6500ft of cable length: you get about 40% of the
cable length as release altitude with a single seater.

--
Bert Willing

ASW20 "TW"


"Todd Pattist" > a écrit dans le message de
...
> "Bert Willing"
> > wrote:
>
> >In Europe, 500-600ft is normally considered as ok to thermal up. Many
launch
> >sites will give you 800-1200ft as release height from the winch.
>
> How far from the traffic pattern would you be located when
> thermalling at 500' and do you have to share with any power
> traffic?
>
> Todd Pattist - "WH" Ventus C
> (Remove DONTSPAMME from address to email reply.)

[Andreas Maurer]

On 12 Aug 2003 14:46:22 GMT, Ray Lovinggood
> wrote:

>The club, 'DJK' in Landau in der Pfalz, Germany, had
>many GREAT winch operators!

Although I know you are biased, thx a lot for the compliment, Ray! :)

>The only instrument, I
>think (hey, this was from 1983 till 1986), was a tach
>and maybe a engine coolant temperature gauge. I think
>they operated mainly by sight and sound. Yep, they
>were great operators! I think their rules stipulated
>at least 100 operations with an instructor before they
>could operate solo.

The 100 launches (on at least 10 deifferent days) are standard
requirements in Germany before you are able to work as a winch driver.
And in 2003 we have a 280 hp turbo Diesel winch that is easily able to
catapult any glider into the air - and we still use the same hightech
gauges you mentioned - the winch is basically driven with the RPM
meter and visally (rope slack).


>
>Ray Lovinggood
>Carrboro, North Carolina, USA
>(who misses winch launching in the Land of Aero Tows)
.... simply go back to the club of your youth... ;)


Bye
Andreas