wrote:
A lot of the clubs here tow with thickish (5/8 inch and some 1/2inch)
poly and nylon ropes, without weak links, and pilots with years of
experience say that no load exerted by the glider can damage the tug -
and in the worst of cases even a 5/8 rope will break before damaging
the Tug (Most often a supercub)

Comments from knowlegable people please ---

Thanks and kind regards

JS

Been there, done that (damaged a towplane). I got my CFI-G ticket in
2-33s and had about 100 hours instructing in these. Then, I
volunteered with another club that used Grob 103s for training. A very
different animal from the 2-33. Things get out of whack much faster.
On my second flight with a fairly new student, I let her get a fairly
impressive PIO going in both pitch (vertical position) and roll
(lateral position). On about the 3rd oscillation, she had a huge loop
develop and, before I could reach the release, she applied full
opposite stick. A godawful sproingggg and we were in free flight. I
noticed the towplane (an L-19) in a fairly impressive rolling dive to
the left and saw the rope trailing free from the towplane end (ie.
attached to the glider) . Once I got my nerves under control, we
dropped the remaining rope over the airport and had an uneventful
landing...

.... Uneventful, that is, until the towpilot came walking over. It
didn't take a genius to figure out that he was not in the best of
moods. I noticed he was carrying something in his hand. The
something was the mangled release mechanism. We had broken it from
the towplane at the mounting bolt; it stayed attached only thanks to
the release cable.

So, in answer to your question, it is possible to damage a towplane
with a glider. At this operation, they used 5/8 braided poly with
Schweizer rings for the main rope. The club which owned the G103 used
"adapters" for the Tost release. I believe (can't recall for sure)
that these were also 5/8.

Erik Mann
LS8-18 (P3)