On Wednesday, June 21, 2017 at 9:43:20 PM UTC+3, Walt Connelly wrote:
The argument that low tow might substantially decrease the chances of
tug upsets is limited. As was pointed out by a previous poster this
might only increase the chance to react by half a second. My personal
experience is that in a sudden kiting situation it's happened before you
could react. If it is a slowly evolving circumstance you might have a
chance to release. There is an altitude below which the outcome will be
disastrous no matter what kind of hook is being used.

In my two experiences both gliders had nose hooks. While the CG hook
might enhance the kiting incident the nose hook requirements are not
going to eliminate it. While I am all for extra training and vigilance
the bottom line is that the human element is still in the picture and
humans make mistakes even with the best of training. One moment of
failure to pay attention on the part of the glider pilot can result in
the death or serious injury of the tow pilot.

The Schweizer hook is well documented to be incapable of releasing the
glider under certan circumstances. The Tost hook on the other hand does
not seem to have these limitations. In virtually every document I have
read regarding this it states, "In some towhook systems, the high
pressure loading on the towhook causes towhook seizure, and the tow
pilot may not be able to release the towline from the towplane. This
situation can be critical if it occurs at altitudes below 500 feet above
ground level (AGL). Upon losing sight of the towplane, the glider pilot
must release immediately." For this reason it is beyond my ability to
comprehend why Schweizer hooks are still in use. At a minimum they
should be inverted and the release handle should be such that olympic
level calesthenics are not necessary for actuation.

My letter is nearing completion and I fully intend to submit it to the
FAA. Will it cause disruption to the sport? Perhaps, but the fact is
that the SSA and their assigns have demonstrated to me that they are
unwilling to step forward in the name of safety and act.

Like others here, I don't have any expectation that involving the FAA will have any good results, and almost certainly not net good results. Quite the opposite.

If I were you, I'd send off a few dozen friendly and informative letters with your experiences and concerns addressed to "The Chief Tow Pilot" at every US gliding organisation I could find the address of.