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Old December 9th 15, 07:52 PM posted to rec.aviation.soaring
Jonathan St. Cloud
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Default 'Canopy Wire Deflector Bars' - Past experience and current thinking


The wire cutters on helicopters are big and while sexy on a helicopter (give it a bad ass look) they would be nothing but drag inducers on gliders. Plus a helicopter operates down low in the dirt (we call it the money curve, as it is out of the HV safety zone). Helicopters need the wire cutters. Gliders are low when landing out and I think it cannot be stated too many times pilots that know of the wires often get distracted and forget the wires are there, so modify and drill into your head WIRES in any off field landing check list. I have been one of those pilots that knew the wires were there and almost hit them (while flying a helicopter).

I seem to remember some very good books by Tom Knauff about off field landings and avoiding wires.

Maybe one of the new data bases will map all the wires and we can upload the data base to our computers, Flarm or whatnots.



On Wednesday, December 9, 2015 at 11:14:21 AM UTC-8, son_of_flubber wrote:
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)