Wing Launch - Can it pull your wings off?

On 8/14/2010 8:17 AM, Derek C wrote:
On Aug 14, 11:30 am, John wrote:
Derek C wrote:
The consequence of using a 10% weaker link would be a greater chance
of a broken weak link and a failed launch, which might be hazardous in
itself under some circumstances.

No, never! A cable break is routine and *never* hazardous in *any*
circumstances. If it is, then something in your operation is seriously
flawed.

Depends on the size and nature of the airfield. Our site at Lasham in
the UK is large and flat, and gives you a wide range of options after
a winch launch failure. I have flown at a small sloping German site
where they launched without a weak link because having a weak link
failure was considered a serious hazard. Having said that the speed
control and quality of their winch launches was very good.

Derek C

Out of genuine curiosity, can you share more details of "small sloping...site"?

I have difficulty imagining a winch site unsuitable for either a straight
ahead landing following an 'early-early' launch problem not also suitable for
a 360-to-a-return-at-the-launch-point for a 'later-in-time' launch problem. I
am assuming a 'reasonably powered winch' of course, which I imagine is the
German norm. Short of an anemic winch with the winch/line stashed down a road
in a copse of woods, my imagination fails me here.

My experience in the western U.S. (generally 5000' msl) is any field
considered 'distance-suitable' for (even marginal) aerotowing is - in a
launch-emergency sense - far more 'emergency-option-friendly' than aerotowing,
because you never get dragged at low altitude over completely unlandable
terrain...which is definitely *not* the case in these parts with aerotowing.
Are there folks winch launching from postage-stamp-sized-fields surrounded by
unlandable terrain using a beyond-the-boundary-winch?

Curiously,
Bob W.

On Aug 15, 2:23*pm, Bob Whelan wrote:
Are there folks winch launching from postage-stamp-sized-fields surrounded by
unlandable terrain using a beyond-the-boundary-winch?

The site where I converted to winch launching was like that. It's
"Jury Hill", at Greytown, near Wellington NZ.

There is a quite long north/south runway, but the interesting
conditions are often in westerly winds. The westerly runway starts
from the southern end of the main runway and at the time I was flying
there had a length of around 300 - 400 m. The winch run was something
like 1200 m with the remainder of the distance to the winch crossing a
mixture of swamp and low "sand dunes" (not actually sand, but
similarly lumpy). The cable retrieve vehicle used a not terribly
straight path through the lumps, including crossing a farm track and
one or two small streams.

With a glider with good brakes (e.g. Ka7, ASK13) and a bit of a
headwind (and you wouldn't use that runway unless there was too much
crosswind for the other one) you could land straight ahead from a
cable break at 200 or 250 ft and make some kind of circuit from 200 ft
or less, so there was always either one good option or else two
reasonable ones for the same runway, plus the option of simply turning
right 90 degrees onto the 1000+ m runway and land with a crosswind.