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

On Thursday, February 20, 2014 9:36:03 AM UTC-5, Chris Rollings wrote:
To repeat one point, our tests left us convinced that the tail-plane on the
tow-plane stalled quite early on in the kiting event, it would need some
tests to check exactly how early. It might be that the nose down angle
would have to be quite small, something that could happen in turbulence
perhaps.

1)It might be possible to recognize a pattern of stick movements and vertical acceleration (and possibly AOA and position relative to the tug) in the GLIDER that would provide a high confidence signature of an imminent kiting event prior to upsetting the tug. The fatal control input is made by the pilot a second or two before the glider kites. Perhaps stage one would trigger an alarm and stage two would trigger a release.

Discovery of the 'kiting signature' would be based on analysis of detailed logs of normal tows, including tows in severe turbulence. Logs would include the parameters noted above and perhaps a video of the tug from the glider. The release device might have three modes 1)normal turbulence 2)severe turbulence mode with higher threshold 3)alarm only mode with simulated release tone. AGL and distance to landable area might lower the release threshold.

Mode 3 would allow me to confirm calibration of the device to my particulars and to gradually increase glider pilot confidence in the device. If it were based on sound science and engineering, I would install a device like this on my glider to reduce my chances of killing a tow pilot even if it somewhat increased my risk of an unwarranted release. Kiting is rare, but I would rather die than possibly kill a tow pilot (especially a young one). I would take my chances on a sound device.

I know that this approach sounds sophisticated, but we live in a time of rapidly advancing technology and dropping costs. There are some good starting points that might only require software extensions once the 'kiting signature' is known, see http://www.diydrones.com/notes/ArduPilot

2)The clubs that I know find it nearly impossible to build a consensus about the most simple and inexpensive things, let alone an automatically activated tug hook. Spend money on a 1:1000000 chance?? There are also good arguments against an auto-release tug hook that might lead to the death of a glider pilot in a hard to justify/defend scenario. Lawyers would have a field day in the USA. Deployment would be spotty and slow. Lots of 'wait and see' decisions. On the hand, I could put a device on my glider and the question would be settled for me behind 100% of tugs.

3)What happens in rotor? Is it possible to stall the horizontal stabilizer of the tow plane? Perhaps it would be good to automatically released in severe rotor, especially if my AGL and distance to a landable spot were within predefined limits. Someday I think I might stay on tow in rotor longer than I should. A mode 3 alarm might provide timely and objective advice to the pilot in rotor. The device could confidently detect inverted flight on tow and auto-release immediately.

4)If you had this kind of sensor and computation power in a glider, it could detect and warn of things like 'imminent spin on turn to final' and other mistakes. Once you had the hardware platform installed a lot of useful safety features could be added.

On 21/02/2014 11:16, son_of_flubber wrote:

.... snips
3)What happens in rotor? Is it possible to stall the horizontal
stabilizer of the tow plane? Perhaps it would be good to
automatically released in severe rotor, especially if my AGL and
distance to a landable spot were within predefined limits. Someday I
think I might stay on tow in rotor longer than I should. A mode 3
alarm might provide timely and objective advice to the pilot in
rotor. The device could confidently detect inverted flight on tow
and auto-release immediately.

4)If you had this kind of sensor and computation power in a glider,
it could detect and warn of things like 'imminent spin on turn to
final' and other mistakes. Once you had the hardware platform
installed a lot of useful safety features could be added.

Are you an Airbus engineer?

GC