Per Steve's comment that the only energy for the glider comes from the towplane engine I have a comment which is in many ways a request for enlightenment.
I had a kiting incident at Moriarty in my 27. All worked out OK, other than fright, mostly because I got off quickly, just as the kite began. How it began is not very clear at all, and much of this is later rationalization I fear, best I can come up with. Skilled glider pilots who watched failed to come up with much, if anything, that helps.
Tow began normally. Within first few seconds, both still on the ground, the tow plane bobbled a bit -- nothing that much given that this was Moriarty on a nice strong thermal day. When I hit the place where the bobble happened the 27 popped into the air a few feet.
My explanation is that I made moves that exaggerated what followed. Anybody with better ideas please join in.
I pushed forward on the stick, the glider began to react, as I flew out of whatever it was caused the bobble, the glider sank fast towards the concrete, so I (rationalizing) assume I moved the stick back to ease the bump.
The glider bounced off the concrete, not that hard but bounced. The one thing I believe I truly remember is that there was a bit of a snake in the rope -- ie some slack.
The tow plane was of course accelerating. So (rationalizing) as the glider bounces up I have at best neutral stick, maybe a bit aft still, and the slack comes out of the rope and the glider at this point began the early stage of a winch launch.
I know that I did two things quickly -- one was hit the release, the other was to get the nose down. Once at flying speed, at maybe 30 feet (I don't have any real guesses from the observers), I moved to the right to use the taxiway. Then, when the tow plane came in sight going like stink out of my way down the runway, I moved back and landed on the runway.
Not a scratch, including to the tow plane's prop. Good towing Mike Stogner..
My point is that there can be a hell of a lot of energy in the rope if for some reason it gains a bit of slack and is then turned into an elastic band.. For some strange reason weak links sometimes do not bust when they might be expected to ...






On Sunday, February 9, 2014 3:27:23 PM UTC-7, son_of_flubber wrote:
This topic was buried in a drifting degenerate thread. I'm wondering if anyone knows more about the tow hook innovation mentioned below by UH.



On Saturday, February 8, 2014 9:31:13 AM UTC-5, son_of_flubber wrote:



Why does the pilot need to pull the release if the glider kites? Why is the release for a deadly tow position not fully automatic? Is a simple purely mechanical, totally foolproof and 100% automatic release not possible? As the guy in the glider, I would be fine with a 100% automatic release. If I kite, release me immediately.





On Sunday, February 9, 2014 5:05:52 PM UTC-5, wrote:



There was a design and prototype of a release like this created many years ago and published, I believe, in Soaring magazine. I know if no one that has adopted this which makes it fairly clear that this is not perceived as a huge problem.