"Ian Forbes" wrote in message
...
Gary Emerson wrote:

if you know of a case where the winch driver had to cut a glider
loose, let
us know here on RAS. We don't need too many specifics, just trying to
see how many times it's happened.

Two cases in our club.

The first happened many years ago to one of our pilots visiting another
club. The glider overran the winch cable and it got caught in the main
wheel. The launch proceeded. The winch driver operated the guillotine -
but it failed to cut the cable. Bystanders radioed a warning to the
pilot. He attempted to circle the winch in a tight turn, but spun in
and was killed in the crash.

The second was more recent.

A group of members tried experimenting with auto-tow. Once again there
was an overrun and the rope got wound around the main wheel axle. At
the top of the launch the tow car observer cut the rope with a knife
and the glider landed safely. (There was no release on the tow car end
of the rope.)

A serviceable, tested guillotine (or release on the tow vehicle for
autotow) is essential.

Of equal importance is a "snake" - a length of garden hose threaded over
the cable between the glider and the retrieve 'chute - which reduces
the tendency for the cable to get snagged on parts of the glider.

One of our club members called it a 'stiffy'. (You Canadians can quit
laughing now.) In my experience, vinyl garden hose becomes a bit brittle in
colder weather and cracks and breaks. I've been using pneumatic hose over
wire rope though our drogue chute for some time and think this would also
work well at the ring end also. It wears well, is a bit more pliable, has
somewhat smaller cross section, works fine in cold weather, is available in
some variety of colors if color coding is needed, and is generally cheaper
than a similar length of garden hose. Of course, used garden hose is widely
available at no cost but may also have become more brittle with age from UV
effects also.

We ran some spectra through the middle of the drogue chute. We abandoned
this after a few launches as there was no resistance to twisting (like wire
rope). For whatever reason, on most launches the chute and lines twisted
and the chute wouldn't open which resulted in its own set of problems. We
were operating on a hybrid rope at the time, with 1000ft of spectra on the
end of our wire rope.

Frank Whiteley