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SAFE Winch Launching



 
 
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  #11  
Old July 5th 09, 02:50 PM posted to rec.aviation.soaring
Alistair Wright
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Posts: 37
Default SAFE Winch Launching

In all this discussion of winches, and the building thereof, no one has
mentioned auto towing. The 'reverse auto tow' is the most efficient launch
method I have ever encountered. We used it at the Essex Club at North Weald
while I instructed there.

You need a nice long runway, about 6000ft is ideal but shorter will do. The
ingredients a

1) Two large automatic cars of about 100BHP - we used retired V6 Ford
Zephyrs - we will call them car1 and car2. A driver and observer (who
watches the glider) are required.

2) A large grooved pulley about six feet in diameter on a rotatable gimbal
and anchored firmly to the ground. The pulley is at the opposite end of the
runway to the launch point.

3) A piece of single strand piano wire the length of the runway.

4) Gliders with pilots.

The wire is passed over the pulley and attached to car 1 which is sitting at
the pulley and the other end to the glider via the usual rope, parachute,
and weak link. Car 2 is sitting at the launch point. Slack is taken up, and
at the all out signal car 1 sets off down the runway towards the glider
which most obligingly lifts off, and sets off up what is now effectively a
winch launch. Meanwhile car 2 sets off following the glider towards the
pulley avoiding car 1, of course, which is driving at about 35- 40 mph
towards the launch point. Glider releases, (we often got nearly 2000ft on a
good day), and car 1 carries on the launch point while car 2 arrives at the
pulley. The cable has launching tackle on both ends, so the next glider is
coupled on and car 2 is connected to the cable and does the next launch ...
need I go on? We used to get 20 launches an hour using this method. No time
is wasted retrieving cables. No need to buy an expensive winch, and the
cheap cable lasted a long time. Ford Zephyrs were also fairly cheap from the
scrap yard, and we had people in the club adept at fixing them. As quite of
lot of American clubs seem to have access to runways I cannot see why they
cannot try this method of launching. I recommend it.

Alistair Wright


Ads
  #12  
Old July 5th 09, 04:08 PM posted to rec.aviation.soaring
Frank Whiteley
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Posts: 1,876
Default SAFE Winch Launching

On Jul 5, 7:50*am, "Alistair Wright" wrote:
In all this discussion of winches, and the building thereof, no one has
mentioned auto towing. The 'reverse auto tow' is the most efficient launch
method I have ever encountered. We used it at the Essex Club at North Weald
while I instructed there.

You need a nice long runway, about 6000ft is ideal but shorter will do. The
ingredients a

1) Two large automatic cars of about 100BHP - we used retired V6 Ford
Zephyrs - we will call them car1 and car2. A driver and observer (who
watches the glider) are required.

2) A large grooved pulley about six feet in diameter on a rotatable gimbal
and anchored firmly to the ground. The pulley is at the opposite end of the
runway to the launch point.

3) A piece of single strand piano wire the length of the runway.

4) Gliders with pilots.

The wire is passed over the pulley and attached to car 1 which is sitting at
the pulley and the other end to the glider via the usual rope, parachute,
and weak link. Car 2 is sitting at the launch point. Slack is taken up, and
at the all out signal car 1 sets off down the runway towards the glider
which most obligingly lifts off, and sets off up what is now effectively a
winch launch. Meanwhile car 2 sets off following the glider towards the
pulley avoiding car 1, of course, which is driving at about 35- 40 mph
towards the launch point. Glider releases, (we often got nearly 2000ft on a
good day), and car 1 carries on the launch point while car 2 arrives at the
pulley. The cable has launching tackle on both ends, so the next glider is
coupled on and car 2 is connected to the cable and does the next launch ....
need I go on? *We used to get 20 launches an hour using this method. No time
is wasted retrieving cables. No need to buy an expensive winch, and the
cheap cable lasted a long time. Ford Zephyrs were also fairly cheap from the
scrap yard, and we had people in the club adept at fixing them. *As quite of
lot of American clubs seem to have access to runways I cannot see why they
cannot try this method of launching. I recommend it.

Alistair Wright


Having launched with EGC at North Weald a couple of occasions many
years ago, my experience was a bit different. We got maybe 800ft in
the K13, but I think the normal launch cars were broken down and a
manually shifted Vauxhall was in use. Each time it shifted, the
drogue chute was over the nose of the glider. I got 1200ft in the SHK
on the other day. IIRC, airspace was limited to 2200ft until about
five miles north. (Have to dig out an old chart that's archived
somewhere). On the days I was there, only one vehicle was in use and
on the first day, there was a wire snarl up on the pulley system (two
big wheels) that delayed things for well over an hour.

However, I do agree that the system may be very efficient. To that
end, the old Cotswold GC system was, IMVHO, more elegant and required
less people to operate
http://www.coloradosoaring.org/think...ey/default.htm

In addition to the long runway, CGC insisted on a lateral 2000ft clear
zone around the pulley. Piano wire is nasty stuff when it breaks
under tension. They also used rather more substantial tow vehicles
and you couldn't launch modern K-21's, DG-50X's and 1000's and single
seaters with Zephyr's. You can't discount the cost of powerful tow
vehicles. We did okay at Enstone GC with an XJ6 Jag on auto tow.
After many years, Cotswold GC reverted to winching.
http://www.cotswoldgliding.co.uk/ They formerly had a history page
about the reverse pulley, but I don't find anything on their web site
now. They do mention that learning to glide is cheaper than learning
to drive though;^)

We do have some long runways in the US, but few are lacking runway
lights or other obstacles that are too close to entertain reverse
pulley launching. On these same runways, it's quite feasible to winch
using the UHMWPE ropes.

Regards,

Frank Whiteley
  #13  
Old July 5th 09, 07:17 PM posted to rec.aviation.soaring
johngalloway[_2_]
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Posts: 46
Default SAFE Winch Launching

On 5 July, 02:38, bildan wrote:
On Jul 4, 5:15*pm, Derek Copeland wrote:



To all my friends in the United States of America.


You may have got the impression from some recent correspondence on this
site that winch launchings is about as risky as bungey jumping or joining
a Kamikaze squadron!


In fact we do many tens of thousands, if not hundreds of thousands, of
winch launches in Europe with only the very occasional accident. Even the
ones we do have are largely avoidable.


Most of the serious winch launching accidents come into the following
categories:


1) Ground loop or cartwheel after catching a wingtip on the ground.
2) Flick spin due to over-rotating after lift off.
3) Stall/spin after a cable break or other launch failure.


These can be avoided respectively by:


a) Pulling the cable release knob if a wing drops.
b) Monitoring the airspeed and controlling the rate of rotation to not
more than 10 degrees/second.
c) Lowering the nose to the recovery attitude and regaining a safe
airspeed before attempting any further manoeuvres. Also learning the most
suitable options for landing safely from various heights.


Things happen much more quickly during a winch launch than they do during
an aerotow, so you do need to engage your brain before you start moving,
not halfway up the launch.


There is starting to be more interest in winch launching in the States,
due to rising fuel and maintenance costs for tug aircraft. However I have
found it somewhat disappointing that some of the leading US protagonists
seem to want to ignore any advice from European clubs and winch builders,
who have a wealth of experience in this method. It's the 'good ol' US
of A always knows best' syndrome. As a result you have already suffered a
fatality and two serious injuries this year from a fraction of the number
of launches that we would do in Europe in the same period.


You already have the most of the basics for winch launching in the US. You
have many vehicles fitted with large and powerful V8 engines and good
automatic gearboxes that can be cannibalised to make decent winches.
Please note that you must disable any kick down arrangement on the
automatic gearboxes. If you join a Yahoo group called 'Winch Design' you
will find a document written by the BGA winching advisor called 'Proven UK
specification' which gives you most of the information needed to build a
good winch. You don't need very fancy and expensive, but as yet unproven,
diesel-hydraulic or electric winches that the above protagonists seem to
think are essential.


Derek Copeland


Written by someone who thinks British automobiles with Lucas electrics
are reliable transportation.



Seems to be a non sequitor considering that Derek was advocating US
not UK engines for winches.

  #14  
Old July 5th 09, 08:57 PM posted to rec.aviation.soaring
bildan
external usenet poster
 
Posts: 655
Default SAFE Winch Launching

On Jul 4, 8:00*pm, Brian Goodspeed
wrote:
Written by someone who thinks British automobiles with Lucas electrics
are reliable transportation.


Written by someone who always claims to know everything about everything -
except that Lucas no longer exist. *They were taken over and bankrupted by
a U.S. company!


Written by someone who actually knows how to use Google.

BTW, I think Lucas was bought by DARPA who was looking for the secret
of light bulbs that emit darkness.

See: www.hermit.cc/mania/tmc/articles/lucas.htm
  #15  
Old July 5th 09, 10:30 PM posted to rec.aviation.soaring
Del C[_2_]
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Posts: 53
Default SAFE Winch Launching

At 18:17 05 July 2009, johngalloway wrote:


Seems to be a non sequitor considering that Derek was advocating US not

UK engines for winches.

Well I would, but most UK cars do not have huge gas guzzling V8 engines
that are big and powerful enough to power a winch, due to our
Government's excessiveand historical taxation of road vehicle fuels.
Possibly V12 Jaguar or Rolls Royce engines would do. if you can find them
cheaply enough second hand. If you want a new engine, then the GM Marine
engines, as used by Skylaunch, are as good and cheap as anything.

Derek Copeland

P.S. Lucas made their initial fortune by selling reversing lights for
Italian tanks in WW2. They worked perfectly!
  #16  
Old July 5th 09, 11:00 PM posted to rec.aviation.soaring
chipsoars
external usenet poster
 
Posts: 90
Default SAFE Winch Launching

On Jul 5, 5:30*pm, Del C wrote:
At 18:17 05 July 2009, johngalloway wrote:



Seems to be a non sequitor *considering that Derek was advocating US not


UK engines for winches.

Well I would, but most UK cars do not have huge gas guzzling V8 engines
that are big and powerful enough to power a winch, due to our
Government's excessiveand historical taxation of road vehicle fuels.
Possibly V12 Jaguar or Rolls Royce engines would do. if you can find them
cheaply enough second hand. If you want a new engine, then the GM Marine
engines, as used by Skylaunch, are as good and cheap as anything.

Derek Copeland

P.S. Lucas made their initial fortune by selling reversing lights for
Italian tanks in WW2. They worked perfectly!


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

I couldn't resist.............

Chip F. - who loves a good winch launch.
  #17  
Old July 5th 09, 11:45 PM posted to rec.aviation.soaring
vaughn[_2_]
external usenet poster
 
Posts: 92
Default 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



  #18  
Old July 6th 09, 01:04 PM posted to rec.aviation.soaring
Chris Nicholas[_2_]
external usenet poster
 
Posts: 198
Default SAFE Winch Launching

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.
  #19  
Old July 6th 09, 02:00 PM posted to rec.aviation.soaring
Del C[_2_]
external usenet poster
 
Posts: 53
Default SAFE Winch Launching

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.

  #20  
Old July 9th 09, 02:30 PM posted to rec.aviation.soaring
Del C[_2_]
external usenet poster
 
Posts: 53
Default SAFE Winch Launching

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
 




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