On Tuesday, December 8, 2015 at 5:20:43 PM UTC-5, wrote:

Why would you do that when there is technology that is demonstrated to work already in existence- and not ugly and dangerous to line crew also?
UH

Demonstrated to work? It's been demonstrated that only a few people feel that the potential benefits of the cage outweigh the immediate drawbacks. A device that practically no one adopts is not a successful engineering solution to a problem.

Say we mount something like the new external Flarm antenna on the nose just in front of the canopy and put a cutter on top. Something relatively cheap that works on practically any glider, that is integrated with something that you get a more immediate benefit from (aka Flarm). A wire cutting device that gets installed on a whole bunch of gliders will avert more injuries in total than a few cages (even if it were to work only half the time).

And sure of course, you'd want a slotted device that blocked the entry of ground crew fingers, a slot that lets a wire slide in and contact the blade. http://www.galls.com/photos/styles/KN208_500_1.JPG

As Jonathan pointed out 'wire strike kits' are used on helicopters. Lots of products and studies on the web. You'd not need something so big on a glider.

The wire cutter idea has been around for a long time
https://en.wikipedia.org/wiki/Wire_cutter_(jeep)