Can anyone tell me more about how a Standard Cirrus handles when
winched?
We use a GMC V8 325 HP petrol engine with standard automatic gearbox.
No problems until now with K8, K6 and Astir Jeans.
I plan to fit my Cirrus with a CG hook. Cirruses imported to France
where all equipped with a nose hook.

Willy VINKEN OO-ZNY


On 22 Mar 2009 10:00:06 GMT, Del C wrote:

As far I can find out, Bill has only done a few hundred launches on rather
underpowered and overgeared old US Gehrlein type winches, plus a couple of
launches on his 'US Superwinch' in a Grob G103 before the drum was
crushed by the synthetic cable, something else I warned him about! The
G103, being low winged and quite heavy, is not prone to over-rotation
accidents anyway, as identified in the Aerokourier report.

I have personally witnessed several vastly overpowered launches involving
K6 and K8 gliders, and have sat through 3 myself, in a K8, a Standard
Cirrus and a DG101. They really do go into a near vertical climb, often
despite the best efforts of the pilot to control the rotation.
Particularly in the DG case I was lucky not to join the accidents
statistics, as I slipped back up the seat as the glider rotated and was
only able to keep the stick just off the backstop with my fingertips.

Just about everyone in Europe, where we we have a lot of winch launching
experience, disagrees with Bill's views. As to engineering data, I have
seen none whatsoever from Bill, whereas I have supplied quite a lot plus
illustrative videos on the Yahoo Winch Design Group.

If you know the position of the belly hook and the centres of gravity and
pressure in a given glider, it should be possible to calculate the
rotational couple for various levels of pull, and at what level it will
overpower the elevator.

Derek Copeland