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Old July 6th 09, 02:00 PM posted to rec.aviation.soaring
Del C[_2_]
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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.