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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