wires

General discussion about the sport of hang gliding
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=31020
there was a close call...
Greg Fergus - 2014/04/01 01:58:03 UTC UTC
Frisco, Texas

Our AT administrator said there was a fatality a few years ago because one of the pins was left out of the base tube on an AT.
Can't find the reference now. Pretty sure it was at Quest, early last decade, Flytec comp, German pilot.
Fletcher - 2014/04/01 02:10:44 UTC

The story I heard about why Wills Wing made the folding basetube.
A pilot flew his Sport, landed, set the glider down and the basetube slipped out of the fitting with the pin securely installed in the down tube fitting but NOT through the basetube. Image Image Image
Rumor has it that WW gave the first production model folding basetube to that pilot.
There were a bunch of those incidents right after Wills Wing came out with the AT hardware, Yours Truly included. One was during a landing flare, the worst was Pete Lehmann a couple hundred feet over Harbor Mountain north of Breezewood. The trees and an undeployed chest mounted chute reduced the damage to about a broken collar bone.
Tormod Helgesen - 2014/04/01 05:17:05 UTC
Oslo

I seldom see people do a preflight check, even at big gatherings with lots of experienced pilots I see them just throw on their harness and fly. I asked a guy once and he said that he checked the glider during setup and that was good enough.
That is good enough for a lot of items.
I've tried to advocate preflight checks and gotten ridiculed as a wimp.
Doesn't your national organization have SOPs and provisions for rating suspensions, reductions, revocations?
I also suspect many of those who do a check don't really know what to look for, so errors may remain undetected.
Then they shouldn't have ratings to begin with. And the fuckin' manuals tell the owners exactly what to look for and do.
A few weeks ago a guy came down under a parachute because he didn't see the broken control cables on his rigid. Bad preflight check or just didn't know (didn't care to learn) what to look for?
Bet he doesn't miss that one again.
I always assemble my glider carefully, but even so I've found errors or things that have happened after setup that would be dangerous to fly with. My list includes a partially installed pip-pin in the basebar...
Not good but shouldn't be a serious problem.
...batten tips flipped open...
BFD.
...open zippers center and tip...
Not serious.
and several others. Only a open zipper at the tip (Moyes) I flew with and that only created a mild turn.
Right.
I don't know why preflight checks isn't done, but maybe it's because most hang glider pilots have no connection to the rest of the aviation world and don't have the training or attitude towards equipment safety that's common there.
Again. You don't have a rating system up there?
Equipment checks is mandatory to teach students here, but somewhere on the way it's lost.
See above.
Whitty - 2014/04/01 06:22:29 UTC

I bet all these pilots did a careful PFC when they started flying. Familiarity breeds contempt. I have seen one pilot clip in and walk to launch with his sprogs flapping around under the wing. Another very experienced phantom pilot also recently forgot to attach is aileron control cables which didn't end well.
Bob Knop - 2014/04/01 06:47:40 UTC
Holland

Hi,

My wing has a bayonet mount, no pins or loose parts which can get lost in the grass.
When installing the bottembar, there is only one way to do it.
You cannot fly the thing when it is not correctly engaged because it than just dangles and hangs downwards.
It has a safety cable inside as well.
Don't you understand that all that engineered in complexity just dramatically increases the likelihood of a catastrophic inflight failure? Should be happening any day now.
It is a Finsterwalder Funfex, this system is tested many years now and usable for any wing, if manufacturers are looking for an other solution.
paicolman - 2014/04/01 07:38:59 UTC

We actually get from day 1 of training the "10-point check" in Switzerland. As you progress, you extend it, but if I'm not mistaken, the "basic" check goes something like:

1. Hang strap / carabiner is ok.
2. Downtube OK, down to the pin on left side (this is what I did not quite correctly).
3. Front side of left wing, upper and lower cables ok, front bars have no dells. Feet on cable and pull wing up, check the screws.
4. Back of left wing, luv lines not entangled and going straight to the kingpost.
5. Back of the wing: wires connected, no worn signals, pick glider up and check it looks symmetrical.
6. Back side of right wing, same as left.
7. Front side of right wing, same as left.
8. Nose: Nose wires ok, nose cone is on.
9. Downtube ok, right pin ok.
10. Reserve in place, secured correctly (pins are not about to get loose).

Of course, depending on your wing you add stuff like closing al zippers and and and, but for a beginners glider, like a Falcon, it's a good start... or should be Image

Then, just before start, the "5-point check" (I hope it's correct this way, it's a long time since):

1. I am Attached to glider
You just became an excellent candidate for launching unhooked and neutralizing everything else you've previously done in your preflight, flying career, and maybe life.
2. Wings are level
3. AoA is ok
4. No traffic in front of takeoff (We fly mountain only here...)
5. Wind ok
GO!
Good luck.
Steve Davy
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Re: wires

Post by Steve Davy »

Whitty - 2014/04/01 06:22:29 UTC

Another very experienced phantom pilot also recently forgot to attach is aileron control cables which didn't end well.
http://www.youtube.com/watch?v=MAr6R4I5bs4
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=31020
there was a close call...

http://www.kitestrings.org/post5858.html#p5858
Mike Lake - 2014/10/30 21:46:35 UTC
Mike Lake - 2014/03/31 12:32:30 UTC

What I mean by stressing the glider is I first grab the two front wires and squeeze them together as hard as I can.
The rear rigging failed when a pilot performed this preflight test yesterday exposing a fault with the connection to the keel. More details when I have them.

The above along with the side wire stress test should be part of everyone's preflight!
What if you're accidentally holding a sharp rock in your hand while you do that? You could do a lot of damage to those wires that way. Sorry dude, bad idea.
Rolla Manning - 2014/10/31 02:51:32 UTC
Keep a close eye on the right side control bar junction Image

http://www.youtube.com/watch?v=2Mofk1y6LKE


do you see anything amiss ?
The...
Austrian Times - 2009/08/28

A German hang-glider was killed when he plunged fifteen metres to the ground after forgetting to do up his leg straps during a flight yesterday in Tyrol.

Local police said the man, 58, took off from a mountain station near Tannheim but was seen clinging onto the hang glider with his hands and with his legs dangling down in front of him, forcing the craft to lose altitude.

They said he was killed immediately when he lost his grip and fell just 200 metres from his intended landing area.
Image

...skipped hook-in check?

The...

http://www.hanggliding.org/viewtopic.php?t=26854
Skids versus wheels
Andrew Stakhov - 2012/08/11 13:52:35 UTC

So I just came back from flying in Austria (awesome place btw). Stark difference I noticed is a large chunk of pilots choose to fly with skids instead of wheels. Conversations I had with pilots they say they actually work better in certain situations as they don't get plugged up like smaller wheels. Even larger heavier Atosses were all flying with skids. I was curious why they consistently chose to land on skids on those expensive machines and they were saying that it's just not worth the risk of a mistimed flare or wing hitting the ground... And those are all carbon frames etc.
...landing?
Dave Pendzick - 2014/10/31 18:11:21 UTC

I almost did this myself & a Paraglider pilot of all people saved my ass! I had put the bolts through the control frame but did not put the nuts on due to a distraction. I had gotten things set up & did not notice the bolts still in my pocket! He came over as I was donning my harness & picked up the glider by 1 down tube & asked out of curiosity "How much do these things weigh???" The bolts had slid out of the holes & the control frame fell apart & the glider came down & hit him on the head.

Thank goodness for the curious paraglider pilot! LOL!
'Cause no fuckin' way were you ever gonna use the preflight check that's specified in all the Wills Wing manuals and has just been described by Mike for his...

http://www.hanggliding.org/viewtopic.php?t=13864
My new wing
gluesniffer - 2009/10/04 18:29:28 UTC

If its a ww, do what their manual says.
If it is a pacair, do what their manual says.
...non Wills Wing glider.
wuffos - 2014/10/31 22:59:21 UTC
Philadelphia

Does WillsWing still make their hinged "ClickClack" basetube that never needs to be disconnected?
Unless you wanna install a pair of pneumatic wheels.
K C Benn - 2014/10/31 23:17:27 UTC
Ogden

PREFLIGHTS ARE SO IMPORTANT !
Aside from sidewire and the related control frame corner pins issues, WHY? Serious incidents relating to issues with the rest of the glider are pretty much statistically nonexistent.
I do mine every flight and still mess up ! The person I fly with does not do an efficient preflight and I worry about him sometimes ! I think what ill suggest is what my instructor and I used to do in the old days. When the gliders are set up after or before are own preflight we also preflight each others glider. (Of course this means he will have to wait until my glider is set up).
Fine. But if you just pause for five or ten seconds before moving out of the setup area and think about the important issue...
This year I have had two times when one of my ribs had come unlatched (causing a turn in my glider).
BFD.
One time I only had my undersurface zipper zipped up halfway, one time when I did not have my VG rope in the cleat and finally one time when my right inner sprog was not zipped up.
These are not the sorts of things that are gonna get you hurt/killed.
Most of these happened @ the SS of POTM where I just landed back on top with a quick fix. This is complete stupidity on my part and could lead to my own or others injury!
Cite an incident in which any one of those issues has resulted in a scraped knee.
I call this old-timers disease (after all I have been flying for 39 years have 1000's of hours in the air blah, blah, blah,) Thanks for reminding me to get back on track Image Image
michael170 - 2014/11/01 03:27:45
Dave Pendzick - 2014/10/31 18:11:21 UTC

I almost did this myself & a Paraglider pilot of all people saved my ass! I had put the bolts through the control frame but did not put the nuts on due to a distraction. I had gotten things set up & did not notice the bolts still in my pocket! He came over as I was donning my harness & picked up the glider by 1 down tube & asked out of curiosity "How much do these things weigh???" The bolts had slid out of the holes & the control frame fell apart & the glider came down & hit him on the head.

Thank goodness for the curious paraglider pilot! LOL!
http://www.hanggliding.org/viewtopic.php?t=25963
Woman killed in B.C. hang gliding fall.
Dave Pendzick - 2014/09/30 17:00:51 UTC

Learn something new!?!? Like what exactly? Remembering to hook in??? If this is new information to someone then they probably shouldnt be hang gliding.
Perhaps you shouldn't be hang gliding, Dave.
Touché.
Rodger Hoyt - 2014/11/01 04:23:37 UTC

WTF - I thought this issue was resolved decades ago when Pacific Airwave started painting the male fitting red, vividly alerting you when the junction wasn't fully joined.
Why did no other manufacturers follow suit? Why must we relearn the same lessons?
michael170 - 2014/11/01 04:39:56 UTC

Think about why this is a dangerous "solution" to the issue:

http://www.youtube.com/watch?v=PYi_0yLKDr8
Dave Pendzick - 2014/11/01 05:17:21 UTC

Go fuck yourself! Image :mrgreen:
2014/11/01 05:56:16 UTC - 3 thumbs up - michael170
michael170 - 2014/11/01 05:52:06 UTC

If you're interested in surviving in this idiot sport then that is the right attitude.
I'm interested in him continuing doing the same things over and over and expecting better results.
MikeLake
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Re: wires

Post by MikeLake »

Tad Eareckson wrote:What if you're accidentally holding a sharp rock in your hand while you do that? You could do a lot of damage to those wires that way. Sorry dude, bad idea.
You crack me up sometimes! :lol:
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

Aw shucks, 'tweren't nuthin'. Just anticipating inevitable Jack Show feedback.
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=33308
Funston Accident
Steve Morris - 2015/08/24 05:06:40 UTC

It has been mentioned on Facebook that the HG pilot who died at Funston today was Rafael Lavin. There is also some ongoing discussion about a possible sidewire failure on the older glider he was flying, but I'm relaying this third hand and can't say if this was the cause of the accident.
Probably one of those assholes who always does the Wills Wing preflight sidewire load test and ground one of them into a sharp rock.
Raffi was a great guy with a wonderful sense of humor.
Yeah, aren't they always.
He will be missed by all of us at the Fort.

Image
Well, he died doing what he loved - losing a wing and slamming back into the slope. How are things shaping up for tomorrow? I have the day off and would really like to take a two or three hour flight in his honor.

Sure didn't take u$hPa long to wipe the records off the database this time.
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=33308
Funston Accident
Tim Dyer - 2015/08/24 20:36:19 UTC

Racing side wires. R.I.P.
Oh! It was a RACING wire! You DEFINITELY don't wanna be doing preflight sidewire load test on those guys - sharp rocks around or not! Sorry, my bad.
---
P.S. - 2015/08/24 21:50:00 UTC

Might wanna edit the thread title to something more appropriate now that we have this clarification.
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=33308
Funston Accident
NMERider - 2015/08/24 21:59:55 UTC

It broke at the Nico-press sleeve. Possibly due to electrolysis. It is a bare copper sleeve on what may be stainless wire. If so, this is a real no-no especially around moisture and far worse with salt air. The damage to the wire is undetectable other than via destructive testing.
Well... Good job then.
The club safety officer is looking into it.
I can hardly wait.
Steve Morris - 2015/08/24 23:10:39 UTC

Here is the photo of the damaged wire.

Image

I heard (3rd hand) that there is a video which shows that the wire failed at launch.
Which tells us that the wire blew at a max loading of almost certainly well under one and a half Gs. Which pretty much confirms what we were pretty much certain of already - that a preflight sidewire load test was not performed on this flying day, or on any of the previous dozen, hundred, whatever.
I don't know how long the glider flew or what the trajectory was after launch, but it was a topless glider so it didn't fold up even with the broken wire. Hopefully we will get a more detailed accident report from those with greater knowledge of the facts.
And hopefully we'll find out that this was a Wills Wing glider and thus have confirmation that the most important and critical preflight check specified in the owner's manual was deliberately skipped as a matter of standard operating procedure and then we'll start hearing a lot less crap from assholes like Red about the dangers to the wires this check entails.

And notice that so far none of the Jack Show assholes have dared breathe a word about this blindingly obvious issue. Reminds me a lot of the standard failure to hook in fatality discussion in which mention of a hook-in check is strictly forbidden.

P.S. Fuck you, Red Howard.
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=33308
Funston Accident
NMERider - 2015/08/25 02:22:17 UTC

Here are some maintenance and pre-flight steps from the T2 and Litespeed RS manuals for everybody's enlightenment.

Image
Image
Good. Now let's count the number of Jack Show total fucking assholes who once again lapse into temporary selective total blindness...
gluesniffer - 2015/08/25 03:28:57 UTC

What a bummer. Image I think he has been there almost every time I have flown the fort. Rip Raffi
One...
raquo - 2015/08/25 03:29:58 UTC

I assume this means that the wire was self-made, not from the manufacturer?
Two...
Takeo Eda - 2015/08/25 04:24:48 UTC
Silicon Valley

Without pointing fingers or attempting to place blame, this appears to be a maintenance related accident. I personally don't know why I looked at hang gliders as different than any other air vehicle but after Sunday I'm going to keep a maintenance log of every user-replaceable component on my two gliders, in combination with my flight log. In addition I plan to keep an extra set of all the wires on my gliders handy just in case. A few hundred dollars is cheap insurance indeed.
Five...
Eric Beckman - 2015/08/25 04:26:49 UTC

So sad. Rafi was such a well-liked guy, and a fixture at the Fort for years. Heartfelt condolences to all family and friends.

I don't remember any year with so many fatalities, and I've been flying since 1975. Oy!

There were a few side wire failures in years past with gliders that had lots of time at Fort Funston, but none resulted in fatalities (that I know of). Coastal flying is especially hard on equipment, and the control bar spends a lot of time in contact with salty moist sandy dirt. A corrosion factory.

While I don't yet know for sure which end of the side wire failed, I would be surprised if it wasn't the control bar end. A new set of flying wires every year or two is inexpensive insurance (even if too the pilot is too cheap to replace them every 6 months or 50 hours). Corrosion keeps working its destructive nature even when the glider isn't being flown.
Six.
Takeo Eda - 2015/08/25 04:30:34 UTC

It was.
Got that one already.
NMERider - 2015/08/25 05:32:42 UTC

I've been around since 1973 and the per capita death rate over the past 18 months seems like it has never been this high.

We had a 2mm side wire failure on a Litespeed at Sylmar back in 2012. The pilots did a fast swoop over the LZ and it went "Twang!". The beefy crossbar barely bowed upward but the hapless pilot had no way of shifting his weight to the side missing the wire and the glider spiraled into the rock-strewn river wash.
Wow! The ideal hang glider landing zone! Lucky bastard!
He suffered only a broken arm and was able to repair the glider which is still flying today. I had heard his racing side wires were pretty well-used.
Probably did the preflight sidewire load test one too many times. Let that be a lesson to y'all.
I had a long phone conversation this afternoon with a private pilot in CO and he relayed story after story to me of familiar types of negligence and fatal accidents in the GA community over the past few years. This trend does not seem to be isolated to our form of recreation.
Image
These hang glider maintenance schedules:
NMERider - 2015/08/25 02:22:17 UTC

Image
are pulled out of manufacturers' asses for the purposes of:
- covering same; and
- selling more wires

They have ABSOLUTELY NOTHING to do with reality.

http://www.hanggliding.org/viewtopic.php?t=13785
Old cables
W9GFO - 2015/08/25 05:33:41 UTC

I've been making a point of performing that step-on-the-side-wire test every time I preflight. That's in addition to close inspection of the crimps. Gives me peace of mind. It's rare that I see anyone else doing the same. I actually feel kinda dorky doing it. I can't be the only one that feels that way but it won't stop me from doing the test.
WHOA!!! A flicker of actual intelligence! On the Jack Show! Who'da thunk. (The rest of you guys be sure to get him on your Ignore list right to keep it from spreading and creating disharmony and unrest.)

This motherfucker would've lost a flying day - or maybe just an hour if he'd carried spares and tools (like I do (did)) - instead of his glider (and life) if he'd just bothered to step on the goddam wire and load it up on the ground before loading it up in the air. Sorry guys, but Darwin strikes yet again.
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Tad Eareckson
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Re: wires

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=33308
Funston Accident
flyzguy - 2015/08/25 06:02:08 UTC

What's 50 lbs? Its a question that's come up by new pilots when very literally looking at the manual.
Try to get the new pilots looking at the right manual. 50 is for toplesses. New pilots aren't flying toplesses. It's 75 for kingposted.
I'm sure its not too magic of a number...
Exactly.
...but one good tip I've heard is to simply put 50 lbs on your bathroom scale with one foot to get a sense of the weight. Someone could do the trigonometry to figure out the resulting line tensions and how they compare to flight loads, but I don't have the energy at the moment. I'll just keep stepping on those wires.
Exactly.
Rick Cavallaro - 2015/08/25 06:35:36 UTC

It depends entirely on how bent the wire is at the load. For sake of argument let's say the 50 lb load is applied in the middle of the wire, and the wire is bent by an angle of theta. We can compute the resulting tension on the wire this way...

sin(theta/2) = 50 / tension

Or:

tension = 50 / sin(theta/2)

So if the wire is bent 10 degrees the tension would be 573 lbs
If it was bent 30 degrees the tension would be: 193 lbs
Rick Cavallaro - 2015/08/25 06:58:24 UTC

Doing some rough calculations and using the attached HG pic, I get that you want the cable to withstand 360 lbs for a 200 lb pilot to do a coordinated 60 degree banked turn with a 50% safety margin (with some assumptions as indicated).

This seams reasonably in line with the 50 lb test.

Calcs:

Length of 1 wing: 568 pixels
wire attach point: 298 pixels
200 lb pilot (we don't count the weight of the wing since it's being supported by the air)
1/2 pilot's weight goes to each side wire.
Let's put the center of lift at 1/3 of the wing span (based on an elliptical loading and some guess work).
Assume the load is taken entirely by the cables - not the cross-bar.

Moment required to hold wing: (568/3) x 200/2
Same moment must be applied by wire attached at 298: 298 * vert_force = (568/3) x 200/2 = 18933
So vert_force on the wire is: 63 lbs (when flying at 1G).
Based on the image the side wires are at an angle of 31 degrees.
Using the equation from the previous post we see that a 63 lb vertical force applied by a wire at 31 degrees results in a wire tension of: 122 lbs
In a coordinated 60 degree bank we'd be doing 2G's - so each wire would be at about 240 lbs.
And you'd want at least a 50% safety margin so that suggests we should test it to: 360 lbs.

http://forum.hanggliding.org/download/file.php?id=26120
Image
Just step on the fuckin' wire and push up until you start getting a little scared. It's a common sense thing. That's all it would've taken to keep this one from happening. The goddam thing blew right after launch ferchrisake.

P.S. Fuck you too, Lauren Eminently-Qualified-Tandem-Pilot Tjaden.
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