'Canopy Wire Deflector Bars' - Past experience and current thinking

From the New Zealand point of view, several things have changed:

- at the dawn of electric fencing, it was common to distribute it via a single high tensile wire quickly added to an existing fence using risers. These could often be quite high so that vehicles could pass under the electric wire at gates, and also so that risers were only needed every 5 or 10 posts. As it was a single wire and the risers perhaps only 2x1s it was not easy to see.

Many was the time, as a lad, that I rode a motorcycle through such a fence by accident.

Hmmm.... reminds me of white water canoeing in the '70's in eastern PA (Neshaminy creek?) one spring. I had the front of the canoe on a fast (spring thaw) but small stream.
Out of nowhere, I saw grass "floating in midair" across the stream. It had caught there when the stream was higher but now the water had receded some and left the grass on the wire.
I barely had time to lay backwards (paddle on top of me, lengthwise) and shout, "Wire!".
It was a barbed wire fence for cattle and it went across the stream.
A wire guide/cutter would have been nice then.

Can't say I ever had an issue with a landing though, but it's sorta like insurance, "You don't like it until you need it".

On Sunday, December 6, 2015 at 7:37:33 AM UTC-7, son_of_flubber wrote:
I found a few mentions of Canopy Wire Deflector Bars in the RAS Archives. One said that the deflectors were mandatory in the Netherlands. What has been experience and what is current thinking? Links and search terms appreciated as I could not find much with initial google search.

Temporary electric livestock fences are a known landout hazard in my area..

Jerry Robertson hit a fence between two railroad tie posts in a libelle, in the 1971 or 1923 Nationals in Marfa, Texas, tore his wings off and severely lacerated head and face. Next time he flew he had bars under his canopy to deflect wires.

gkemp

On Tuesday, December 8, 2015 at 7:45:39 AM UTC-7, gkemp wrote:
On Sunday, December 6, 2015 at 7:37:33 AM UTC-7, son_of_flubber wrote:
I found a few mentions of Canopy Wire Deflector Bars in the RAS Archives. One said that the deflectors were mandatory in the Netherlands. What has been experience and what is current thinking? Links and search terms appreciated as I could not find much with initial google search.

Temporary electric livestock fences are a known landout hazard in my area.

Jerry Robertson hit a fence between two railroad tie posts in a libelle, in the 1971 or 1923 Nationals in Marfa, Texas, tore his wings off and severely lacerated head and face. Next time he flew he had bars under his canopy to deflect wires.

gkemp
How quickly you forget. I was working on records in Utah, landed my 1-35 in a field, misjudged a ditch across the center, hit the barbed wire fence. Broke the canopy, one strand hit me in the face and broke, one, ended up in my mouth and one across my throat, 9 stitches. If it hadn't been a Schweizer, with skid down and hitting the edge of the road, the barbed wire would have killed me. Still thought that was very unusual and never but in Wire Deflector Bars.

gkemp "NK"

In the accident report which I posted, I was told the glider struck the
wire such that the wire was under one wing and above the other. There
was no escaping having the wire penetrate the cockpit.

On 12/8/2015 2:57 AM, Eric Munk wrote:
As mentioned they are no longer mandatory in The Netherlands. They were
introduced in the 1960s I believe after a string of accidents (some fatal).
Since then fields have become a lot bigger, obstacles a lot less and air
traffic a lot busier. We opted to replace all fences around the airport by
ditches, and deleted them from our fleet to improve on look-out. Also,
modern gliders seem less prone to injure pilots compared to the older ones
where the wire would go into the gap of the canopy front (compare K8 line
of fuselage/canopy to discus and you'lle see what I mean).



--
Dan, 5J

OK- Now that everybody has chimed in with reasons to have wire deflectors (or not), does anybody have a viable design that will work with a modern sailplane? I would be interested in seeing if a deflector is practical to use. Got a lot of barb wire out here in the desert, and I knew a pilot who lost an eye and got some pretty bad scars from having a wire slice into his canopy.

Here are some photos from inside (and outside) of my glider which has wire protection bars.

https://www.icloud.com/sharedalbum/#B0V5aVbMKXgkQp

At first they drove me nuts. I felt like I was in a cage. It bothered my visibility. But after 10 flights or so I do not even notice they are there.. I somehow learned to unconsciously adjust my head as needed to make sure I have cleared any blind spots.

These wire strike accidents are rare but still happen. A glider just ran into wires during a contest this fall at New Castle a couple months ago. Thankfully, the pilot was OK. I'm not sure if the wires hit the canopy or not, but it does make me feel better having at least some, minimal protection on my glider.

I will admit I was very close to removing them at first.

7T

On Tuesday, December 8, 2015 at 2:02:34 PM UTC-5, Mark628CA wrote:
OK- Now that everybody has chimed in with reasons to have wire deflectors (or not), does anybody have a viable design that will work with a modern sailplane? I would be interested in seeing if a deflector is practical to use. Got a lot of barb wire out here in the desert, and I knew a pilot who lost an eye and got some pretty bad scars from having a wire slice into his canopy.

Chip has them (OEM?) in his ASW-24, likely the first time I saw them in a sailplane.
I would consider a ASW-24 "fairly modern".

On Tuesday, December 8, 2015 at 2:02:35 PM UTC-5, Sean Fidler wrote:
Here are some photos from inside (and outside) of my glider which has wire protection bars.

https://www.icloud.com/sharedalbum/#B0V5aVbMKXgkQp

At first they drove me nuts. I felt like I was in a cage. It bothered my visibility. But after 10 flights or so I do not even notice they are there. I somehow learned to unconsciously adjust my head as needed to make sure I have cleared any blind spots.

These wire strike accidents are rare but still happen. A glider just ran into wires during a contest this fall at New Castle a couple months ago. Thankfully, the pilot was OK. I'm not sure if the wires hit the canopy or not, but it does make me feel better having at least some, minimal protection on my glider.

I will admit I was very close to removing them at first.

7T

I believe the issue was, "Hit wires, sudden stoppage too far above ground", the resulting (likely near vertical) impact did a job on the sailplane.
It was part of a thread within a day of the incident.
I would say, "The pilot survived", I WOULDN'T say he was "OK".

Really, really sorry to hear that. There has been very little information about this particular accident other than a wire was involved. What I did hear was "fairy banged up" but will recover. Again, very sorry to hear of the higher severity of the accident than I had imagined. I'm wishing for the best possible recovery. Wires are bad news.

On Tuesday, December 8, 2015 at 2:02:34 PM UTC-5, Mark628CA wrote:
does anybody have a viable design that will work with a modern sailplane?

Pure speculation.

For light gauge electric horse coral wires... Maybe a firmly mounted 'hook knife'mounted on a 12" whip to the fuselage just in front of the canopy might catch and cut wires (more often than not). Integrate it into an externally mounted Powerflarm antenna. Mount two. One on either side to get the sight blocking off center and gain redundancy (redundant antennas and cutter)..