At 16:43 25 March 2009, bildan wrote:

Everyone has experienced the imprecise surging when backing a car with
an automatic transmission to align a tow ball with a trailer hitch.
Imagine trying to control the acceleration a 1000 pound glider with a
drive train intended for a 6000 pound road vehicle.

Anyone who thinks any of this is not true, needs to produce some valid
measurements to the contrary. I believe validated data.

Bill,

I have been involved in a lot of discussion a debate here in Scotland abut
the merits or otherwise of Skylaunch winches and I have been launched by
one and have launched about 8 gliders with one. As you well know because
you have been told this on another forum the auto box is a complete
non-issue. It changes into third during the ground run and stays in fixed
ratio top gear throughout the launch - only exeptionally changing down
under very heavy loading during the main part of the launch. The early
upwards gear changes are undetectable to the glider pilot.

I don't know what you consider to be validated data if not 40 odd winches
over many years of use without problems with controllability related to the
auto box. I can understand your wish to promote the merits of tension
controlled winches but to do so by denigrating a clearly successful
alternative design reveals more about your mindset than the winch in
question. It is a shame that you have no practical experience of the
Skylaunch which in our club trials worked equally successfully for K8s to
Duo Disci

I am pretty sure that the long term future of winching will rest with much
more complex designs but there is none currently available that is proven
by experience in terms of time of use and numbers built. The Hydrostart
is certainly not yet convincing and is very expensive and, correct me if I
am wrong, the US version is not launching yet. Considering the cost of
winches, and the fact that once a club becomes winch orientated then
proven reliabilty is critical, then I would reckon that it will be 5-10
years before it becomes wise to risk the purchase of what is now an
experimental winch design. That is not to say that the the US tension
controlled winch will not be successful from the start - just that it is
better to let others act as the early adopters.

John Galloway