Does anyone use a tug tow hook that releases automatically whenglider kites?

On Saturday, February 22, 2014 8:04:43 AM UTC-5, Karl Striedieck wrote:
On Sunday, February 9, 2014 5:27:23 PM UTC-5, 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.. Although FAA approval might be an obstacle, a system that would work would be to connect the elevator cable to the tow release cable such that the last small increment of travel toward full up elevator of the tow ship would pull the release. An additional concern that tow pilots should be aware of is the possibility of an accelerated stall right at release of a kiting glider. With full back stick the angle of attack might increase so rapidly the tug pilot wouldn't get the stick forward fast enough.

Full back stick is where I am during run up, beginning of take off roll, and commonly in the flare.
A combination of inputs might be made to work if including:
Climb power above some threshold
Plus some predetermind degree of up pitch control input
Plus some predetermined air speed.
Maybe find a way to add in a rate of deceleration input.
Maybe add reduction in G force for some predetermined time
If the combinations fall into the specified range, you have as problem.
Need is to avoid a single input that may be false.
FWIW
UH

I think the Aussies figured this out.

Nose hook on glider plus low tow (and suitable training for the high-low transition, which really isn't that hard) solves the problem.

Now, is the key part of the solution the glider hook position, or the tow position?

Without any statistics, my scientific wild-ass guess (SWAG) is about 80% nose tow hook on glider and 19% low tow; I'll concede 1% to training just because I know how poorly most glider pilots listen to any training when "safety" is involved...

Seriously, I think the key is to stop towing on CG hooks in turbulent conditions. Or at least tell the tow pilot when a CG hook is being used and make sure the glider pilot is fully aware of the potential for kiting. Perhaps insist that CG gliders go to low tow.

And if anyone thinks you can release a towplane Schweizer release under tension, especially with an upward component, I suggest that you try it on the ground. You may be unpleasantly surprised.

OT, been watching "Rake" (the original Aussie version) on DTV. Excellent!

Now, where is that Bearcat flight manual I've been reading?

Fun thread, hope is makes people think a bit about what CAN happen on tow, and saves a life or two.

Kirk
66

On 23/02/2014 01:35, kirk.stant wrote:

Without any statistics, my scientific wild-ass guess (SWAG) is about
80% nose tow hook on glider and 19% low tow; I'll concede 1% to
training just because I know how poorly most glider pilots listen to
any training when "safety" is involved...

I'd agree with that split. I'd also add that there are no Schweitzer
hooks in Oz. That helps a lot.

GC

Kirk 66