At 19:34 11 July 2009, johngalloway wrote:

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 some 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

Totally agree with all of that. I believe the Hydrostart winch on which
the Hydrowinch is based costs an astonishing 500,000 Euros, so it ought to
be damn good! Makes a Skylaunch 2 at 90,000 Euros sound very good value,
and it is a tried and tested design. And remember that they do a cut down
and simplified version called the Skylaunch 3 for a lot less than that,
if you can do without air conditioned cabs etc.

Until recently we had a demo Skylaunch with a GM 502 High Torque engine.
On that you could open the throttle up to the preset as fast as the gas
strut would allow you to. However we have just bought two new winches with
the High Power engine and I initially got some complaints about banging the
tails of K13s down a bit hard at the start of the ground run, so I have
slowed down opening the throttle to about 3 seconds, as you suggest. You
also have to start backing off the throttle for the last third of the
launch to avoid overspeeding the glider. As long as you know that you have
to do this it is not difficult.

What the Skylaunch does brilliantly in my opinion, is to give a very
consistent ground run and rotation, whatever type of glider you are
flying. With our old Tost winches you could get anything from a
dangerously fast snatch into the air to a slow and ponderous ground run
with a risk of a wing drop. If a launch starts right it tends to stay
right, so we get consistently higher launches from them, if only for that
reason.

Derek Copeland