SAFE Winch Launching

"chipsoars" wrote in message
...

My understanding is that Lucas, Prince of Darkness, was also
responsible for the invention of intermittent windshield wipers.

Well, sort of. They just weren't supposed to be intermittent at the
time.

History seems to assign the invention of true intermittent windshield
washers to Robert Kearns.
http://www.theautochannel.com/news/2...25/005398.html
I seem to remember a movie...

Vaughn

Just to put the record straight about pulley launching at North Weald
(UK):

There were at least three different generations of Ford trucks used
for launching at North Weald, with the Ford Zodiac cars as a brief
interlude. The Vauxhall that Frank mentions must have been on a day
during the old generations of second hand vehicles which were
certainly not the best. Somebody must have used their own private car
for launching – I do not recall the club ever had a Vauxhall between
1970 when I started and 1991 or thereabouts when we had to stop wire
launches at North weald.

For anyone to judge the capability of reverse pulley launching by a
sight of one off day in the 1970’s is not a fair comparison.

I joined the club in 1970, and they were using ex-US or Canadian
service Ford F100 trucks. A few years later, the second-hand supply of
these ran out, and old Mark IV Ford Zodiac’s were tried as an
affordable alternative with sufficient power.

In 1978 we undertook a major re-equipment. As well as two K13s and a
tug, we bought two brand new Ford F100 trucks. They had 5.8 L V8
engines and propane gas tanks. (We still have one of the engines. It
went on for a life after death, as a replacement engine in an ex-ATC
Eagle-type winch, which we still have as a backup winch at Ridgewell.)

In 1988, these were wearing out. We and Lasham ordered new Ford F250
trucks. We had two, but I can’t remember how many Lasham ordered at
that time. They had 7.5 L V8 engines, supercooling, LPG conversion,
and cost £10,251.25 each including delivery and VAT. This was the
net price after I was able to arrange a healthy discount through my
connections with Ford at that time, which included from time to time
arranging publicity photographs at North Weald with gliders in the
background when they wanted to launch a marketing campaign for a new
vehicle.

These were the last tow trucks we used for launching at North Weald.
(In the early 1990s, the council which had bought the aerodrome banned
wire launching at the request of powered aircraft operators at the
aerodrome. They had concerns about mixing wire and their aircraft at
the same time.)

The last version of the “pulley” that we used had two wheels on a
pivoting frame, with a short straight between them which formed an
anvil. A Guillotine arrangement ran through the horizontal pivot, so
we could meet the requirement to be able to chop the cable during a
launch if necessary. As far as I know, the Aston Down device did not
permit such a safety arrangement.

As a general comment on life, launching, and the universe, I would add
that there are two ways (at least) to contemplate a technique that you
have not used before.

1. Invent it from the beginning yourself and make the same mistakes as
everybody else did.
2. Learn from people who eventually got it right and do it similarly.

Yours in a spirit of friendship and cooperation.

Chris N.

I am not quite sure why this thread has turned into a discussion about the
merits of tasty warm British beer against that cold p*ss water the Yanks
drink, an attack on the late lamented Lucas car component company, and the
merits or otherwise of reverse pulley autotowing.

In the same period as Chris describes below, we did straight autotowing at
Lasham using various models of US Ford F series pick up trucks. This was
mainly because the winches available at the time were so poor. Once Tost,
Supacat and Skylaunch started building decent quality winches, it was
realised that you could get get much higher and safer launches, so the
changeover was made in the mid 1980's. I believe that only two UK clubs
still autotow in any form.

Derek Copeland

At 12:04 06 July 2009, Chris Nicholas wrote:
Just to put the record straight about pulley launching at North Weald
(UK):

There were at least three different generations of Ford trucks used
for launching at North Weald, with the Ford Zodiac cars as a brief
interlude. The Vauxhall that Frank mentions must have been on a day
during the old generations of second hand vehicles which were
certainly not the best. Somebody must have used their own private car
for launching =96 I do not recall the club ever had a Vauxhall between
1970 when I started and 1991 or thereabouts when we had to stop wire
launches at North weald.

For anyone to judge the capability of reverse pulley launching by a
sight of one off day in the 1970=92s is not a fair comparison.

I joined the club in 1970, and they were using ex-US or Canadian
service Ford F100 trucks. A few years later, the second-hand supply of
these ran out, and old Mark IV Ford Zodiac=92s were tried as an
affordable alternative with sufficient power.

In 1978 we undertook a major re-equipment. As well as two K13s and a
tug, we bought two brand new Ford F100 trucks. They had 5.8 L V8
engines and propane gas tanks. (We still have one of the engines. It
went on for a life after death, as a replacement engine in an ex-ATC
Eagle-type winch, which we still have as a backup winch at Ridgewell.)

In 1988, these were wearing out. We and Lasham ordered new Ford F250
trucks. We had two, but I can=92t remember how many Lasham ordered at
that time. They had 7.5 L V8 engines, supercooling, LPG conversion,
and cost =A310,251.25 each including delivery and VAT. This was the
net price after I was able to arrange a healthy discount through my
connections with Ford at that time, which included from time to time
arranging publicity photographs at North Weald with gliders in the
background when they wanted to launch a marketing campaign for a new
vehicle.

These were the last tow trucks we used for launching at North Weald.
(In the early 1990s, the council which had bought the aerodrome banned
wire launching at the request of powered aircraft operators at the
aerodrome. They had concerns about mixing wire and their aircraft at
the same time.)

The last version of the =93pulley=94 that we used had two wheels on a
pivoting frame, with a short straight between them which formed an
anvil. A Guillotine arrangement ran through the horizontal pivot, so
we could meet the requirement to be able to chop the cable during a
launch if necessary. As far as I know, the Aston Down device did not
permit such a safety arrangement.

As a general comment on life, launching, and the universe, I would add
that there are two ways (at least) to contemplate a technique that you
have not used before.

1. Invent it from the beginning yourself and make the same mistakes as
everybody else did.
2. Learn from people who eventually got it right and do it similarly.

Yours in a spirit of friendship and cooperation.

Chris N.

Pros and Cons of winch launching:

PROS:

1) A new professionally built winch will probably cost less than a new
towing aircraft. If you build your own from scrap automobile/truck parts
it will cost considerably less.

2) A winch doesn't require a highly qualified and certificated driver,
Certificates of Airworthiness, 50 hour checks, etc, etc. Some routine
maintenance is required though.

3) Low carbon footprint. A winch launch consumes less than a fifth of the
fuel required for an aerotow

4) No aircraft noise complaints.

5) Given proper training and pilot awareness, it's pretty safe.

6) Winch launching is cheap; at our club less than a third of the cost of
a 2000ft aerotow, even with professional winch drivers. So ideal for
training and circuit bashing. A decent soaring pilot can usually get away
from the sort of heights achieved, in the right conditions.

7) You don't have to learn accurate formation flying behind a tug.

8) You are unlikely to kill the winch operator, as opposed to a tug pilot
who can be killed if you get too high or too out of position.

9) Above all IT'S FUN.

CONS:

1) Launch height is limited by by the length of the cable run and the
headwind component. On a still day you will at best get about 45% of the
cable run. Launching directly into a headwind will improve this.

2) You can't get towed to a source of lift, such as a cumulus cloud or a
ridge. You always end up right over the winch.

3) Pilots need to be fairly well trained and switched on to deal with
launch failures and cable breaks.

4) Winch Cables may conflict with power flying at a mixed operation site.

Derek Copeland

To Alan Larson.

I tried to reply to your questions directly, but your spam filter doesn't
seem to like my tiscali email address. So the answers a

1) How high you get depends on the length of the run, the power of the
winch (ours are Skylaunches with plenty of power and good control) and the
headwind component. At my club we typically get about 1600ft in no wind and
2000ft launching into a 10 knot headwind. Our standard aerotows are 2000ft,
but you can go as high as you like, depending on your needs and the depth
of your wallet.

2) A wingtip touching the ground during an aerotow ground run is not
normally an issue for aerotowing, provided that it's on a smooth surface
or very short grass. Having said that I once did £5.5k's worth of damage
to my glider trying to aerotow out of a cowfield with rather clumpy grass,
when I caught a wingtip in a particularly lush clump before I could get the
wing up and groundlooped violently. With a winch launch, because you are
putting in a lot of energy very quickly, a cartwheel can develop very
quickly; hence the need to abort the launch if a wing drops.

You also have to fly the glider in such a way that you can always recover
from a launch failure, which basically involves a short initial safety
climb and controlling the rate of rotation. If you pull up like a Saturn
rocket taking off, you are in severe danger or either flick spinning on
the cable, or stalling heavily into the ground if the cable breaks or the
winch fails early on!

3) It's surprising how often you find a thermal straight off the top of a
winch launch. I suppose this is because the heat generated by the winch
engine triggers off a thermal. Otherwise you head off to the nearest
cumulus cloud, or look for birds or other gliders circling. It is
considered polite to move out of the way before the next glider is ready
to launch and not to circle low down in the base leg area, but that often
allows 5 minutes or so in which to climb, by which time you may be high
enough not to conflict.

4) When training new members we normally start them off with aerotows to
get them used to being in the air and to learn how to control the glider
before transferring to the winch. Having said that, many UK clubs do all
their training by winch.

5) For obvious reasons you have to have a system in place that prevents
aerotows and other aircraft from taking off at the same time as a winch
launch is taking place. We have an appointed 'launch point controller'
whose job it is to coordinate all movements by radio. We also place the
winch launch point about 500 yards in from the downwind boundary and on a
grass area away from the main runway, so most gliders, tugs and light
aircraft can land short of there without conflicting with the cables.
Unfortunately this costs us some potential launch launch height. If we use
the full length of the airfield (1900yards) we can get 2500ft winch
launches even in nil wind. We sometimes do this when things are quiet, but
then you have to stop launching whenever there is an aircraft or glider on
approach. Also the higher you take the cables, the more likely they are to
drift over something expensive after a cable break.

Regards,
Derek Copeland






At 13:30 09 July 2009, Del C wrote:
Pros and Cons of winch launching:

PROS:

1) A new professionally built winch will probably cost less than a new
towing aircraft. If you build your own from scrap automobile/truck parts
it will cost considerably less.

2) A winch doesn't require a highly qualified and certificated driver,
Certificates of Airworthiness, 50 hour checks, etc, etc. Some routine
maintenance is required though.

3) Low carbon footprint. A winch launch consumes less than a fifth of
the
fuel required for an aerotow

4) No aircraft noise complaints.

5) Given proper training and pilot awareness, it's pretty safe.

6) Winch launching is cheap; at our club less than a third of the cost
of
a 2000ft aerotow, even with professional winch drivers. So ideal for
training and circuit bashing. A decent soaring pilot can usually get
away
from the sort of heights achieved, in the right conditions.

7) You don't have to learn accurate formation flying behind a tug.

8) You are unlikely to kill the winch operator, as opposed to a tug
pilot
who can be killed if you get too high or too out of position.

9) Above all IT'S FUN.

CONS:

1) Launch height is limited by by the length of the cable run and the
headwind component. On a still day you will at best get about 45% of the
cable run. Launching directly into a headwind will improve this.

2) You can't get towed to a source of lift, such as a cumulus cloud or
a
ridge. You always end up right over the winch.

3) Pilots need to be fairly well trained and switched on to deal with
launch failures and cable breaks.

4) Winch Cables may conflict with power flying at a mixed operation
site.

Derek Copeland

On Jul 11, 2:00*am, Derek Copeland wrote:

At my club we typically get about 1600ft in no wind and
2000ft launching into a 10 knot headwind. Our standard aerotows are 2000ft,
but you can go as high as you like, depending on your needs and the depth
of your wallet.

This week we were getting as high as 1900' from 3900 feet of rope at
9000 feet density altitude with little wind with the Hydrowinch. With
no gear shifting at all, the Hydrowinch is MUCH smoother than any
winch with an automatic transmission.

Skylaunches are just like old Gerhleins with new paint - they use
exactly the same components. They are not particularly well
controlled since they use road vehicle torque converters and automatic
transmissions free to shift gears when they please. The old junk
Gerhleins around most US clubs are probably the only winches in the
world worse than a Skylaunch - but they are a LOT cheaper.

BTW, notice how Derek has to reply to himself to get any conversation
at all?

On Jul 11, 9:36*am, bildan wrote:
On Jul 11, 2:00*am, Derek Copeland wrote:

At my club we typically get about 1600ft in no wind and

2000ft launching into a 10 knot headwind. Our standard aerotows are 2000ft,
but you can go as high as you like, depending on your needs and the depth
of your wallet.

This week we were getting as high as 1900' from 3900 feet of rope at
9000 feet density altitude with little wind with the Hydrowinch. *With
no gear shifting at all, the Hydrowinch is MUCH smoother than any
winch with an automatic transmission.

Skylaunches are just like old Gerhleins with new paint - they use
exactly the same components. *They are not particularly well
controlled since they use road vehicle torque converters and automatic
transmissions free to shift gears when they please. *The old junk
Gerhleins around most US clubs are probably the only winches in the
world worse than a Skylaunch - but they are a LOT cheaper.

BTW, notice how Derek has to reply to himself to get any conversation
at all?

That you, Lennie?

-T8

Unlike Bill Daniels, I tell it as it is without exaggerations and unproven
assumptions. The figures I gave are for a K13, which winch launches less
well than a K21 because the belly hook is too far forward. K21's get
about 200 feet higher, especially when flown solo.Also Bill Daniel's
winch is using synthetic Dyneema cable which adds about 150 feet to the
launch compared with the 4.5mm stranded steel cable we use.

Dynema cable is superb stuff, but unfortunately 5 times more expensive
than steel. As cable replacement is one of the major costs in winch
launching, this makes it less economic.

The Skylaunch winch gives well controlled, correctly speeded launches for
every type of glider from slow old vintage single seaters up to big heavy
two-seat DG1000 turbos. It is also very easy to drive (I am a winch
driver). The gear change all occur during the ground run and are totally
smooth and imperceptible from the glider end.

If you build a winch with an automatic gearbox, you have to disable the
kick down function and tweak the box so that it changes up at fairly low
revs. I agree with Bill that you can't just stick an unmodified automatic
gearbox into a winch without encountering the sort of problems that seem to
beset Gerhlein winches. It is also important to get the overall gearing
correct.

For a good quality Skylaunch launch of a K21 to 2300ft into about a 5 knot
headwind see:

http://www.youtube.com/watch?v=4ArI5_1PE_Y

BTW. My reply was genuine in response to an email from a gent called Alan
Larson. I tried twice to reply by email, but got delivery failure
notifications with the text:
The following message to email address was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'5.0.0 All tiscali sends is spam'

OK Tiscali is not the best ISP in the world for keeping out spam, but even
so.....? I have removed Alan's actual email address to prevent him getting
any spam.

Derek Copeland



At 13:36 11 July 2009, bildan wrote:
On Jul 11, 2:00=A0am, Derek Copeland wrote:

At my club we typically get about 1600ft in no wind and
2000ft launching into a 10 knot headwind. Our standard aerotows are
2000ft
,
but you can go as high as you like, depending on your needs and the
depth
of your wallet.

This week we were getting as high as 1900' from 3900 feet of rope at
9000 feet density altitude with little wind with the Hydrowinch. With
no gear shifting at all, the Hydrowinch is MUCH smoother than any
winch with an automatic transmission.

Skylaunches are just like old Gerhleins with new paint - they use
exactly the same components. They are not particularly well
controlled since they use road vehicle torque converters and automatic
transmissions free to shift gears when they please. The old junk
Gerhleins around most US clubs are probably the only winches in the
world worse than a Skylaunch - but they are a LOT cheaper.

BTW, notice how Derek has to reply to himself to get any conversation
at all?

In article
,
bildan wrote:

On Jul 11, 2:00*am, Derek Copeland wrote:

At my club we typically get about 1600ft in no wind and
2000ft launching into a 10 knot headwind. Our standard aerotows are 2000ft,
but you can go as high as you like, depending on your needs and the depth
of your wallet.

This week we were getting as high as 1900' from 3900 feet of rope at
9000 feet density altitude with little wind with the Hydrowinch. With
no gear shifting at all, the Hydrowinch is MUCH smoother than any
winch with an automatic transmission.

Skylaunches are just like old Gerhleins with new paint - they use
exactly the same components. They are not particularly well
controlled since they use road vehicle torque converters and automatic
transmissions free to shift gears when they please. The old junk
Gerhleins around most US clubs are probably the only winches in the
world worse than a Skylaunch - but they are a LOT cheaper.

BTW, notice how Derek has to reply to himself to get any conversation
at all?

My club used to have a very good winch. It was a one-off called the
"Eagle Winch" and was designed and built by one of our members. He got
his initial glider training in Germany and had knowledge of quality
winches. That winch is now with the Philadelphia Glider Council, I
believe. We were forced to let go of it because we moved to a municipal
airport that was incompatible with winch operations (crossing runways).

The Eagle winch has an automatic transmission. However, in our operation
it was locked into 2nd gear for normal conditions. In strong wind, we
used 1st gear. No gear changes necessary. It was very easy to operate
and became even more so after the steel cable was swapped our for plasma
rope by the second owners at the Memphis club. At our original field,
with 4000 feet of cable out, we could easily launch our single seaters
to 2000 feet if we had any headwind.

On 11 July, 14:36, bildan wrote:
On Jul 11, 2:00*am, Derek Copeland wrote:

At my club we typically get about 1600ft in no wind and

2000ft launching into a 10 knot headwind. Our standard aerotows are 2000ft,
but you can go as high as you like, depending on your needs and the depth
of your wallet.

This week we were getting as high as 1900' from 3900 feet of rope at
9000 feet density altitude with little wind with the Hydrowinch. *With
no gear shifting at all, the Hydrowinch is MUCH smoother than any
winch with an automatic transmission.

Skylaunches are just like old Gerhleins with new paint - they use
exactly the same components. *They are not particularly well
controlled since they use road vehicle torque converters and automatic
transmissions free to shift gears when they please. *The old junk
Gerhleins around most US clubs are probably the only winches in the
world worse than a Skylaunch - but they are a LOT cheaper.

BTW, notice how Derek has to reply to himself to get any conversation
at all?

This account of the performance of the Skylaunch winch is, as Bill has
repeatedly been told previously elsewhere by pilots who actually
operate or launch on Skylaunch winches, utterly false and his
obsessive denigration of it is disgraceful. Our club had a Skylaunch
winch for evaluation for six days a couple of weeks ago. The
smoothness of launch is faultless and a vast improvement over Supacat
and Tost winches

The fact that the automatic transmission can shift gears "when they
please" is a complete non issue. The gear changes up at the start of
the launch occur within the first 2-3 seconds (timed by me) and before
the glider has rotated into the climb. The gear changes are
completely imperceptible in the glider. None of numerous pilots on
the ground near the winch during launches note the upwards gear
changes without being prompted to listen out for them - an even then
there was soe debate about whether they could be detected.
Occasionally the autobox changes down to second during the mid launch
when under load but at no time was any of the many pilots launched
aware of any gear change.

The operational mechanisms of the Skylaunch are not designed to
"control" the launch so it is not surprising that it does not do so.
What it does have is an interconnected maximum throttle position guide
that takes into account the type of the glider and the headwind
component. This means that each glider is effectively provided with a
winch with an appropriately powered engine for itself and the wind
conditions in the mid launch. The winch driver still has to control
the start and end of the launch - by advancing the throttle control at
an appropriate rate at the start (about 3 seconds IMHO) and backing
off the power at the top. The predictable response of the good old GM
V8 to load means that the plot can pull into a steep climb without
fear of overspeeding.

The new US winches may turn out to be brilliant but Bill's emotional
bias invalidates him as an objective reporter in my opinion.

John Galloway