On Thursday, May 21, 2020 at 4:53:54 AM UTC-7, wrote:
Unfortunately, I think we can discount any load sensing concepts (weak links, load cells, etc) for the following reason. Kiting events are rare and so for any system to be widely adopted, the frequency of any nuisance releases of any system need to be similarly rare or hopefully less rare. Otherwise the system will be a PIA and will be removed because of the nuisances.

Two situations that come to mind that would/could occur that would lead nuisance releases are the following

1. This spring the ground was soft and it took 100% power from the Pawnee to get a 2 seat glider to start to move.

2. Slack line situations, either real or simulated for training. The impact load when the slack comes out will likely overpower any weak link and then we've created a PTT.

As such, I suspect for a KGARS system to be workable, it needs to go back to a parallel operation of the mechanical tow release in the cockpit, but only when very specific upset conditions are detected. (airspeed, pitch angle, elevator position, etc.)

KISS is nice, but if weak links worked reliably for upsets, we'd probably be doing it already.

With all due respect.

Mark

Doing proper state estimation would prevent any unexpected KGARS activation.. For example, your ground roll situation the towplane is obviously not flying (inadequate airspeed, still at ground elevation and no increase in pitch angle). I assume that you mean a slack line will break the weak link, which isn't an inadvertent activation of KGARS. This IS a solvable problem.

Tom