It's worth trying to understand these accidents and being ware of "solutions" that don't address the root cause. I think I've worked harder on this than many, so I'll share my summary. For those that don't know me, I've been instructing for 3 years and have about 2000 hours in gliders and towplanes since 1986. I am not timid (thanks Rick :-)).

The Skyline accident is an outlier. Video evidence shows that the glider deck angle never gets out of normal limits. It was not a kiting event. However, it's perfectly clear that the glider PIC lost situational awareness for several seconds and left the normal tow position at very low altitude (~200' iirc). The video + audio suggest that it is likely that the towplane's elevator authority was compromised before tow separation. Although this cannot be established with certainty, we do know that the tow line angle was unusually steep and that the tension became high enough to break the rope without a slack line event. I'll bet a year's worth of tow fees you can't break a rope in this manner without compromising the tug.

The similar accident I am aware of is the Sugarbush takeoff accident in 1999.

https://app.ntsb.gov/pdfgenerator/Re...Final&IType=FA

It's similar to the Skyline accident in that it involves a reasonably experienced pilot in a modern nose hook equipped glider giving in to a cockpit distraction on departure (open canopy) and allowing the glider to fly well outside normal positional limits. It's unclear to me if this became a kiting event or not, but it's clear that the towplane's elevator authority was badly compromised. Observers stated that the tow rope was "vertical" prior to separation. The towplane was forced into the ground and came to rest inverted.

We don't have an easy way to collect statistics on the gliders involved in upset accidents and incidents. The glider type is generally not mentioned in an accident report concerning a towplane, unless the glider is also wrecked. The anecdotes I know of suggest it's most often Schweizer iron, with the 2-33 figuring prominently. The anecdotes generally suggest a kiting event as described in the work of Rollings, et al.

It's easy to see why. The stick pressure on tow cannot be trimmed out in any 2-33 I've flown. The forward stick force required to maintain formation with the tug is substantial. The departure from normal tow position (high or low, doesn't matter), should you momentarily release forward pressure for any reason, will be extreme and potentially catastrophic for the tow pilot.