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

On Wednesday, December 9, 2015 at 4:33:54 PM UTC-5, Dan Marotta wrote:

I can see the benefit of all those externally mounted wire
cutters/flarm antennae - more drag!* Since my glider won't be so
equipped, I'll realize an immediate benefit!

Less drag and more Adventure!

On Wednesday, December 9, 2015 at 2:14:21 PM UTC-5, 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)

You be the first- report back.
I'd stick with the proven solution if I were to do it.
UH

I second Hank on this. If you're worried about a power line in the grill while gliding, a canopy cage is the answer. Unfortunately, 99.999% of the time it seems like overkill.

'Zactly!

On 12/9/2015 2:53 PM, son_of_flubber wrote:
On Wednesday, December 9, 2015 at 4:33:54 PM UTC-5, Dan Marotta wrote:

I can see the benefit of all those externally mounted wire
cutters/flarm antennae - more drag! Since my glider won't be so
equipped, I'll realize an immediate benefit!
Less drag and more Adventure!

--
Dan, 5J

On Wednesday, December 9, 2015 at 9:09:48 PM UTC-5, Sean Fidler wrote:
If you're worried about a power line in the grill while gliding, a canopy cage is the answer.

Power line?? Are you saying that a canopy cage offers some small measure of protection (any protection at all) from the kind of wire strung between telephone poles (telephone wire, house power, coax cable)?

I was talking about the bare 12 gauge wires strung between fiberglass rods maybe 1 meter above the ground.

On Thursday, December 10, 2015 at 2:16:18 PM UTC-5, son_of_flubber wrote:
On Wednesday, December 9, 2015 at 9:09:48 PM UTC-5, Sean Fidler wrote:
If you're worried about a power line in the grill while gliding, a canopy cage is the answer.

Power line?? Are you saying that a canopy cage offers some small measure of protection (any protection at all) from the kind of wire strung between telephone poles (telephone wire, house power, coax cable)?

I was talking about the bare 12 gauge wires strung between fiberglass rods maybe 1 meter above the ground.

How about the wire strung across the field from a tree to the shed in the other corner?.
Fences are only one part of wire hazards.
UH

If you are worried about wires other than those separating pastures, the wire cutting through the canopy won't be your real problem... but at least it will shorten your suffering.

Bert
Ventus cM TW

On Thursday, December 10, 2015 at 2:16:18 PM UTC-5, son_of_flubber wrote:
On Wednesday, December 9, 2015 at 9:09:48 PM UTC-5, Sean Fidler wrote:
If you're worried about a power line in the grill while gliding, a canopy cage is the answer.

Power line?? Are you saying that a canopy cage offers some small measure of protection (any protection at all) from the kind of wire strung between telephone poles (telephone wire, house power, coax cable)?

I was talking about the bare 12 gauge wires strung between fiberglass rods maybe 1 meter above the ground.

An "in general comment" (directed to this thread, not SoF)..... what about the wire "just in the tree tops you don't see" while going into a field?
This can slide across the BOTTOM of the fuselage.

You WILL take the flying speed and STOP all forward progress and turn it into a "nose down until you hit something harder".
I arrived at an accident site maybe 20 minutes after a similar event. It was in "central PA" where I had just done a field retrieve of another competitor (I was also in the contest). As we headed home, we saw rescue groups at the other end of a field.
We stopped and found yet another competitor had had an accident. He was trying to "land short" and didn't see the wires in the tree tops that hung his gear and made him hit the ground ~90* nose down ~30' below the wires.

So, we're proposing "wire cutters" on the top of the fuselage, a "wire cage inside the canopy" as well as wire cutters (that retract) under the fuselage so we don't have to worry about wires going UNDER the nose on a retract?

Bold ambition, would be worthwhile (in some cases), better than "making a call to loved ones" after the fact.

If you want to be "perfectly safe", don't do anything that has some danger in it.

[ever see the statistics about fatal falls in the bathroom of your house?]

Everyone has to weigh "risk & reward", we ALL do things that have some risk. We strive to mitigate the risk (training, not doing whatever on a certain day, etc.).

I've had a canopy wire deflector bar set in my ASW 24 since 1992. Before ordering the glider, I had some questions, which Gerhard Waibel kindly answered. IIRC:

1. No, it won't stop a power line. But it might guide it up and over my head.
2. Yes, it can be installed aftermarket but it's easier at the factory.
3. Yes, it can be removed and replaced in the field to use only during contests (but I never have).
4. Yes, it's a potential danger in a crash but my head would probably only strike it a glancing blow.
5. No, it doesn't affect headroom. My head is between the two bars that extend aft from a hoop over the instrument panel.
6. Yes, it affects visibility. Gerhard sent a drawing and I taped up the canopy of my old glider to check it. I used to fly in the back seat of a Ka-7 so compared with that, you're in a fishbowl.

I like it. I've never removed it. It's not really in the way although you learn to move your head a bit to look around it. I use it to hang a rearview mirror that I flip down for gaggles and to check if I'm leading and go through a bump so I can see if the guy off to one side turns behind me in the thermal I missed.

It cost about $300 installed at the time. If I bought another new glider, I'd definitely order it again. Not having one wouldn't prevent me from buying or flying a used glider but I'd probably look around for one to install.

I don't plan to ever use it. I also don't plan to use my parachute or to rely on my PowerFLARM to keep me out of trouble. To those who say a wire strike or wire fence encounter are unlikely so why spend the money, I suggest you talk to the safety zealots who keep asking why I don't buy a transponder ("Isn't your life worth $2,000?). Sorry, that's unfair. The wire deflector was inexpensive protection against a hazard that had hurt or killed several pilots I knew of. I've only seen one other glider (an ASW 28) with it in the U.S.

Perhaps the biggest factor: it looks REALLY cool. According to most spectators, I have the only glider with a roll bar.

PM me with any questions.

Chip Bearden
ASW 24 "JB"
U.S.A.