Weak link question

[Matthew]

Gee Tad, Sorry I'm not at your beck and call 24/7. I don't always check out every thread on the forum. I've been otherwise pre-occupied the last couple of day. To answer you question, Bill Bennett and the instructor from Ohio were using a piece of nylon cord and not a weaklink. As to you assertion that a weak link has never saved anyone at Highland, how do you know? If a weak link breaks just prior to a lockout, that is saving someone's life. You are arguing that because weak links sometime's break when the pilot is not in danger that they don't do any good when the pilot's life is in danger. That is beyond absurd.


Matthew

[RedBaron]

A weak link certainly saved my butt on one occasion. I came off the cart crooked in my Litespeed, over-controlled and would have quickly been in a close-to-ground neck-breaking lockout if the weak link hadn't snapped right away. They can't be weak enough in my humble opinion, especially if you fly sluggish top performers.

[Tad Eareckson]

Hi Matthew,

Thanks much for coming back on. And, again, I'm very sorry you got hurt and wish you the best as far as recovery is concerned.

I don't expect everyone to read everything that comes across the wire, but if one has chosen to participate in a particular conversation...

I don't know - or particularly care, as it's completely irrelevant - what Bill Bennett and Mike Del Signore were using as a weak link but I believe I remember Christy telling me it was a multi-strand job. It was installed between the tow line and two point bridle and they were using a three-string installed at the bridle apex with the lanyard running back to the port side of the port pilot which was Bill.

The weak link was reported to have been four to five hundred pounds - which would have put ME - solo - well within USHGA specs. For that tandem ride we're talking a G rating of no more than 1.0 and that's significantly less than what Karen uses.

I wrote about this accident fifteen months ago but - obviously - things haven't sunken in. So here we go again...

It was hot, they were heavy, the trike wasn't up to the job - powerwise. None of those parameters does a whole helluva lot for climb rate. They were unable to stay level with the tug and that deficiency in altitude put them in dangerously close proximity to the wake. They PUSHED OUT to try to keep up and from about that point on were living on borrowed time.

They knew that. They knew that the only thing that was keeping them alive was the minimal tension they were getting through the string and that as soon as either they lost it or the stall progressed - whichever came first - the show was gonna be over. That's why they didn't release and that's why the last thing in the world that they wanted to have happen was a weak link break.

You're in luck right know 'cause Ridgely will be closed for the season shortly before you're gonna be ready to hop on a cart again. So you'll have until March to do this homework assignment I'm about to give you.

Go to:

http://www.ushpa.aero

Click on "Members Only" and log in.

About the first thing you'll see is a little box that says "Special Links".

It's got two items. Click on the top one - "Safety Briefing: Tandem AeroTow"

READ IT and do what it says.

Take particular note of the sentence that starts off:

>
SHOULD THE TANDEM GLIDER BECOME UNATTACHED FROM THE TUG DURING THIS MANEUVER...
<

and make sure you don't skim too fast through Paragraph 7.

>
As to your assertion that a weak link has never saved anyone at Highland, how do you know?
<

'Cause:

1. I've never heard of anything that comes close to qualifying for that prize;

2. around August I posed the question to Sunny and neither has he; and

3. as much as a great many people would LOVE to stick it to me - I STILL ain't hearing SHIT.

>
Matthew Graham

2008/11/03 18:40:45

If a weak link breaks just prior to a lockout, that is saving someone's life.
<

To oversimplify just a bit... A WEAK LINK DOESN'T AND CAN'T BREAK JUST PRIOR TO A LOCKOUT. Even the 0.50 to 0.75 G crap I was flying for all those years wasn't breaking before I was way, way, way into a lockout. And I could always release before it did.

>
Matthew Graham

2008/11/03 18:40:45

You are arguing that because weak links sometime's break when the pilot is not in danger that they don't do any good when the pilot's life is in danger. That is beyond absurd.
<

>
Steve Kroop, Tow Committee Chairman - 2006

2005/02/09 19:32

Weak links are there to protect the equipment NOT THE GLIDER PILOT. Anyone who believes otherwise is setting them selves up for disaster.
<

>
Donnell Hewett
Department of Physics
Texas A&M University-Kingsville
MSC 175 Kingsville TX 78363-8202

2005/02/08 18:30

It is impossible to design a weaklink to release the pilot when he loses flight control because there is no correlation between towline tension and flight control.
<

>
Dr. James Freeman
Dynamic Flight
Trawalla, Victoria, Australia

2005

The purpose of a weak link is solely to prevent the tow force from increasing to a point that the glider can be stressed close to or beyond its structural limits. Lockouts can and do occur without increasing tow tension up until the point where the glider is radically diverging from the direction of tow. At this point tension rises dramatically and something will give - preferably the weak link. Given that a certified glider will take 6-10G positive a 1.5G weak link as opposed to a standard 1G weak link should not significantly increase the risk of structural failure. It will however significantly decrease the probability of an unwanted weak link break.
<

>
Re: [Tow] Weaklinks
2008/10/07 18:09:32
GreggLudwig@...
skysailingtowing@yahoogroups.com

Tad-

I find your latest post quite interesting. I must say it has taken me sometime to get used to or accept your writing style but you make some valid points. When you refer to "ushpa" you are actually referring to me, Chair of the ushpa Tow Committee. Our next Tow Committee meeting will be at Chattanooga, TN 23-25 October. Can you attend?

Gregg Ludwig
ushpa Tow Committee Chair
<

>
Danny Brotto

2007/05/16 23:15:19

Weak links are not a secondary release system...
<

So, Matthew, are you starting to get the slightest clue that some of these people on similar wavelengths might actually know what they're talking about?

Janni,

So how come you didn't release? (Yeah - That's a rhetorical question.)

[Danny Brotto]

A weak link certainly saved my butt on one occasion. I came off the cart crooked in my Litespeed, over-controlled and would have quickly been in a close-to-ground neck-breaking lockout if the weak link hadn't snapped right away. They can't be weak enough in my humble opinion, especially if you fly sluggish top performers.

An instance where the weak link could have broken and I’m glad it didn’t…

I had the Axis on the cart with the AOA a bit high, launching to the west, with a moderate 90 degree cross from the left. I came out of the cart rolled and yawed to the right with the upwind wing flying and the downwind wing stalled. It was rather dramatic. If I had released or if the weak link had broken, the downwind wing would have further stalled and I would have cartwheeled into terra firma in an unpleasant fashion. I held on tight gaining airspeed until the downwind wing began flying, got in behind the tug, and continued the flight.

Sunny later told be he was about to give me the rope and I thanked him to no end that he didn’t. Lesson learned, check AOA on the cart especially in crosswinds.

-------------------------------------------------------------------------------------

An instance where the weak link held and it would have been nice if it had yielded…

On another instance, I was towing behind a trike being piloted by Bill Bennet as part of a demo at Fairfield (my sailplane port.) These were the early “experimental” days of aerotow. We were using a center-of-mass tow system, a three-ring circus release, and a fairly short rope. Bill commenced the tow, I came off the cart, and Bill started a rapid climb. This put me below the trike, stalled, and soon into the prop wash and tug wing-vortices. My Axis began to roll to the right, I tried to release but the polypro towline had some slack and the release mechanism held tightly. The line then tightened. I do not remember what kind of weak link was being used but with the mounting pressure I thought for sure it would break; but it didn’t. I was rolling past 90 and gave the release one last yank. It released, I completed a wing over just over the tree line, and came in for a nice landing. Bill and I debriefed about the pull-up. The subsequent tow, without the rapid climb out, went okay.

Lessons learned, abandon the three-ring circus and use a decent release (I purchased the then “new-fangled” Wallaby Release) and you can’t count on the weak link to get you out of an emergency situation.

Danny Brotto

[Matthew]

Tad,

Just because you wrote an article on Bill Bennet's accident doesn't make you an expert on the subject. You aren't an NTSB investigator. As to Sunny not responding to your post, Sunny isn't addicted to the forum like you and I can't recall Sunny ever posting. As to your argument, it still doesn't hold water. I could argue that weak links work because they have never had a towing fatality at Highland. People use weak links to tow at Highland, there aren't any fatalities at Highland. Ergo, weak links save lives.

So yes, I have no conclusive evidence regarding the use of weak links. But neither do you.


Matthew

[Tad Eareckson]

Five hours, fifty-six minutes, twenty-one seconds. High point of my year.

From hope for a rational, informed, intelligent discussion with promise for making progress back down to the usual opposite.

So Matthew,

What article are you talking about?

I didn't write an article. I didn't say I was an expert but - what the hell - compared to where you're coming from I'm a fucking genius. Meaning - of course - that I have the ability of your average ten year old to be able to predict what's gonna happen when the kite string breaks.

What post that Sunny didn't respond to are you talking about?

You could argue that weak links have saved lives but you'd have to be able to cite some evidence. Your one attempt was a rather miserable failure based upon a popular urban myth. I'm still waiting for any example with fewer than two asterisks.

On the other hand, I, in fact, HAVE witnessed and CAN document a whole lot more destruction caused by weak link breaks than you can their alleged benefits.

I know of only two potentially serious launch incidents at Ridgely (prior to Danny's post I only knew of one). Both of them could have been bad news if tension had been lost at the wrong time.

By the definition of whatever imbecile it was who wrote the HGFA rule concerning weak links - I haven't flown with one for a couple of years. There's nothing on my end of the tow line that's gonna break when I start pulling significant Gs.

Over the course of ten seasons at Ridgely I've been in dangerous situations three times that I can recall offhand (all of them my own fault and nothing more).

Chad, Sunny, and Adam were all pretty sure I was gonna get majorly creamed at the conclusion of my very first flight there on their very first day of operation. I myself was seriously considering the the possibility.

While the situation was not directly attributable to a weak link break, I wouldn't have been in it had not the goddam thing popped a few seconds off the cart for absolutely no reason. People are ALWAYS safer going up than they are coming down.

My tow problems ended the moment I stopped using a weak link 'cause now I'm the one making the decisions and exercising the control. Same goes for the few other folk who've beefed up to something reasonable.

Janni,

Did Danny's post have any effect on your humble opinion? I thought I detected something of a glow when I presented that scenario to you in a discussion we had at Ridgely.

[Matthew]

Tad,

You talked about the Bill Bennet accident and the said

"I wrote about this accident fifteen months ago but"

You also said you posted the question to Sunny about weak links and he never responded.

Do you ever read the stuff you write?

matthew

[Tad Eareckson]

Yeah, Matthew, with respect to Bill Bennett, I like it when you put quotation marks around something I actually said.

What I was primarily referencing was my post of 2007/08/01 11:56:37 in which I dedicated twenty-five words over the course of two sentences to address a clueless reiteration of a clueless accident report.

Eleven of those words were a quotation of the clueless reiteration so only fourteen were actually mine.

Although that miniparagraph covers most of what you need to know about this crash, it does not constitute an "article".

And neither do a few other short scattered references I made to that accident around that period.

You would have done well to copy, paste, and quote what I said with respect to Sunny too 'cause - as it is - you added a "t" to a word I actually used and invented a lot of the rest. After the medication wears off a bit please go back and READ WHAT I ACTUALLY SAID.

Back to Bill/Mike...

People who use the "NTSB investigator" crap on me (you're not the first) tend not to have the capacity to understand things themselves.

If you want to make a stab at understanding this accident yourself all you gotta do is read the tug pilot's account - 583 words - and the cause should be glaringly obvious. You don't have to be a rocket scientist or NTSB investigator to see it. You just have to be able to tie a halfway competent fifth grader on a reading comprehension test.

If it's over your head and/or you don't trust my interpretation...

Run it by Sunny - as I did. He amended my understanding of the shit that hit the fan by explaining how and why that configuration would have been extremely vulnerable to wake turbulence.

And, yeah, I do read the stuff I write and on the rare occasions when someone catches me on something I deal with it.

Right now you've got a bit of a backlog of issues with which to deal.

[RedBaron]

I'm not against mouth releases or whatever else you want to use. I like the solutions Tad came up with, there, I said it before, I'm saying it again. Danny's examples from an ancient past when I was still crapping into my diapers are very interesting to listen to, no doubt, but do they really still apply to tow operations in 2008/2009? I mean, high AOA in 90 degree cross winds on a glider I've never heard of sounds pretty much like you're asking for it. His second example also reads more like "we had no clue as to what we were doing" rather than anything else. Please, guys, I'm begging for contemporary case studies by someone other than Tad. I probably witnessed 50 broken weak links this summer at Highland. I didn't witness one case when the weak link should have yielded but didn't. But I did witness pilots launching in nasty conditions. And let's not forget Paul Tjaden who would have been screwed by a stronger weak link.

[Tad Eareckson]

Janni,

Thanks for weighing in again. (And Matthew, thanks for not weighing in.)

And thanks for the plugs - but the multi-string was Steve's idea.

I too would LOVE to get contemporary case studies by someone other than Tad. Two problems though - people tend not to give enough of a rat's ass to participate and dangerous AT incidents are extremely rare anyway.

I totally agree with you that both of these problems could have been taken care of well prior to the point at which things got ugly. But that's irrelevant. We only need to look at them in terms of textbook examples of what a weak link can and can't do - and both of those are contrary to the popular perception.

We have to recognize that shit CAN and, in fact, DOES happen. Damn near all the time it comes off it's clear of the ground and of no consequence whatsoever. But just damn near all the time.

Sometime a while back this season Bob Koshmaryk got dust devilled right off the cart, dragged a tip, and got into an oscillation problem. They were getting worse so he did EXACTLY what he should have and released on the way back from one. If he had released or been released or had a weak link pop at the wrong time he could have ended up being the second area ATer to get a face full of titanium within three seasons.

And you yourself were relying on luck to help keep us below a one to one ratio.

So let's say these incidents are happening at a rate of one per twenty thousand tows. That means that your individual chance of getting into a serious low level situation is about zilch. But just one Holly in a decade of towing is too goddam many - especially when a little better training and a lot better equipment would make that sort of thing a virtual impossibility.

There's no freakin' way I'd tow with a downtube mounted actuator. I would if I had to - but I don't have to. NOBODY has to.

>
I didn't witness one case when the weak link should have yielded but didn't.
<

I'd be amazed if you witnessed one case when the weak link should have yielded - PERIOD. I've never experienced nor seen one.

No, I haven't forgotten Paul Tjaden. But he's got those two asterisks I was talking about earlier.

Here's his opening line regarding the incident...

>
The lockout Lauren mentioned was precipitated by my attempt to pull on more VG while on tow.
<

OK, nobody's enough of an idiot to screw with the VG before there's a bit of daylight between him and the ground.

The other asterisk is that he was using a release for which he had to reach.

(There would have been a third asterisk but, since he wasn't able to reach it in time, the fact that it's performance sucked so much that it might not have functioned anyway is irrelevant.)

Now let's assume that the VG distraction had nothing to do with the severity and speed of the lockout and move him down a thousand feet.

He's dead - no matter what he's using for a weak link. Steve is who'd I put my money on in that race.

>
And let's not forget Paul Tjaden who would have been screwed by a stronger weak link.
<

NO. WRONG. INVALID.

He broke a weak link at about 1.3 Gs of tension. Let's give him a 3.0 G link. Tell me how he gets screwed?

(I've taken the liberty of fixing the grammar.)

>
A weak link is there to protect the equipment - not the glider pilot.
<

At altitude a three G weak link will leave you a completely intact glider with which to fly away.

>
Anyone who believes otherwise is setting himself up for disaster. The pilot actuating his release is the way to save himself.
<

He's talking about you, Janni. Odds are you'll never again have another launch incident like that but you're not gonna get away with two more if you keep relying on a weak link of any strength to do your job for you. Put your brake lever on your basetube - like Matthew did.

[Matthew]

Tad,

Here's is what Tow Me Up says about weak links.

*************

Weak Links - Probably the most important item in any tow system. A weak link acts like a fuse, in that it responds instantaneously to an overload condition in the tow system. There are many things that can produce extreme and unplanned loads on the tow pilot. Some of the overloads we have seen include an overzealous tow operator, line dig or jamming of the towline, vehicles and boats running over the towline and dragging it away - with the pilot still attached, pilot entering a very strong thermal on tow. Typically a weak link that breaks at 75% of your inflight load is desired. (ie. If you, your gear, and glider weigh 300 pounds; you should use a weak link with a 225 pound breaking strength). Weak links are essential to prevent overloading your glider, as they limit the maximum force that can be exerted on it to 75% over your normal inflight load. Some pilots feel towing causes severe stress or damage to their gliders. Our experience has shown that towing causes little noticeable wear, and frankly our gliders are exposed to 100% over their normal inflight load when we do a simple 60 degree banked turn. If it is unsafe for the glider to perform steep turns, you probably wouldn't want to be flying it anyway.

We are big fans of testing, and virtually all of the products on this site are tested to failure to ensure they perform as designed. We do a combination of computer modeling using a finite element analysis program to predict loads in areas of stress, and destructive testing using load cells and strain gauge testers. A weak link is useless if you don't know what strength it breaks at in a predictable manner. We use only Dacron or Polyester weaklink line specially manufactured for us to our specifications and each batch of line is tested to verify its actual breaking strength . We are big fans of sewn weak links, since they break in a very predictable manner at the rated strength of the line used to make the link. Sewn weak links are offered in a wide range of breaking strengths. These are the ultimate in ease of use since they don't require any fiddling to tie, and you know exactly what load they will break at. We also carry a wide range of Calibrated weak link line with instructions to tie them so they break in a predictable fashion at a predetermined load. We have even added a page to show you how to build your own Weaklink tester to calibrate the breaking strength of your own links for around $100 from readily available materials.

**********

Pay particular attention to the first line-- "Weak Links - Probably the most important item in any tow system".

Your argument, as best as I can dicipher, is either--

1. Weak links aren't necessary.

or

2. If you hit the release in time, then you don't need a weak link.

So, please clarify your position. Try to avoid the mish-mash of cut and paste and non-sequiturs and comments to various people. Please, simply state your position on the matter.

Matthew

[Batman]

Shocker ... first time I read the forums in 6 weeks and Tad is arguing weak links. I don't think I've ever met anyone who loves to hear himself talk more than Tad ... surely no one on this forum! At least I haven't missed much ... argument looks the same. Same piss poor attitude ... See ya in another 6 weeks ...

P.S. Culinary School Rocks ... no weak links and no Tad

[Tad Eareckson]

Gee Matthew, I'da thunk the first thing you'd have wanna have done would have been to apologize for the crap you wrote earlier. You coulda regained some respect from me that way, but... Go figure.

So, still unable to provide a single instance of an AT weak link break anywhere ever that was totally desired and necessary, you copy and paste stuff from a guy who's an expert on towing paragliders from a payout winch mounted on a boat blasting up and down the Columbia River but has zilch experience with hang gliders and even less with aerotowing them (and, note, it's pretty much impossible to aerotow a paraglider).

OK, if that's the best you can do, we'll go with it.

I don't know why you pasted the second paragraph 'cause it's totally irrelevant to the discussion, but looking at the pertinent stuff...

>
Weak Links - Probably the most important item in any tow system.
<

The people who have their shit together in aerotowing understand that CONTROL is the main safety issue and that weak links have absolutely nothing to do with that equation. A weak link can only be of any use after you've flunked the test.

>
A weak link acts like a fuse, in that it responds instantaneously to an overload condition in the tow system.
<

Yeah, so? A hang glider isn't much worried about overload until it passes six Gs. With or without weak links we virtually never get into a situation in which that could become an issue.

Is there anything else we need to discuss there?

Stuart is a good guy, smart, has a great web site, and runs a smooth ship.

Here's what else he has to say (on one of my other threads)...

>
2008/11/04 15:54

Will weaklinks prevent injuries to pilots who have crappy launch skills and get drug across the ground on launch? Will they protect against lockout, or even a vertical lockout if the pilot is dumb enough to have the line come tight going downwind? Nope and Nope. The weaklink protects the equipment to ensure the pilot has something left to fly. It's up to the pilot to decide if they are capable of flying it. Weaklinks don't make better pilots than reserves do, and frankly they are in about the same class.

I think a weak link is essential. It's sole purpose is to ensure that maximum designed tow forces are never exceeded.

Stuart Caruk - Director of Research and development
http://www.TowMeUp.com - TowMeUp@...
(360-887-0702) Voice - (360) 887-1930 Fax
23102 NE 3rd Avenue, Ridgefield, WA USA 98642
<

which is ONE HUNDRED PERCENT FUCKING PRECISELY what my position is.

[Tad Eareckson]

Dear Mister Moderator,

I don't know what your understanding of this issue is but I'm hoping that by this point you've noticed that there's a consistency of position amongst the less brain damaged people in the sport, the USHPA Tow Committee, the USHPA Standard Operating Procedures, the FAA, the physics folk, and what a lot of the smarter pilots are doing.

This discussion began with a new pilot raising a concern that his rate of weak link breaks were off the scale.

Danny, one of those smarter (and better) pilots I had in mind, provided very concrete evidence of one of the points I've been trying to get across for a very long time - that the use of understrength weak links is a potentially lethal (as well as wasteful) practice.

Kevin, also well into that category, also concurs that the kind of nonsense that we accept as par for the course should not be happening.

And, as you note, the discussion was fairly civilized, calm, and - I'll add - academic.

Then Matthew comes in with some bewildering ad hominem attack.

You called him on it. Thanks. It needed to be done.

But his post was basically just an annoyance. It didn't do me any harm - it just make him look like a jerk.

But where he did the real damage to this discussion was to repeatedly misquote me and misrepresent what I said. That can make ME look like a jerk to the many sloppy readers who frequent this wire.

That's a serious issue as far as I'm concerned. That's how come they've got libel laws out in the real world.

I had to waste a lot of time and energy dealing with it, it significantly derailed the discussion, and he gets to skate free.

Then Chris emerges from the woodwork to join a discussion in which he is monumentally unqualified to participate and drags things down even further with a naked personal attack. Search the archives and try to find any indication of him having something positive to contribute to any discussion that requires an understanding of the equipment we use and the science behind it.

Notice he didn't/wasn't able to address or refute anything I said so he did the only thing within the normal range of his capacity - toss yet another stink bomb.

So why bother with the stupid crack of 2008/10/29 and then just let this other sludge slide?

This is where and way all of these conversations start going down the sewer and it always happens 'cause nobody 'cept me calls these folk on much of anything. What was it that Ben said about a stitch in time?

[brianvh]

Geez Tad;

He's a moderator, not a copy editor. NOT his job to check the accuracy of what people say, just whether they get so obviously offensive that even a casual reader will be taken aback. Chris may be in the gray area, Matt much less so. In fact, I think you were far more offensive to Matt than he was whether or not he misrepresented you. Please, give it a break.

[Flying Lobster]

Shocker ... first time I read the forums in 6 weeks and Tad is arguing weak links. I don't think I've ever met anyone who loves to hear himself talk more than Tad ... surely no one on this forum! At least I haven't missed much ... argument looks the same. Same piss poor attitude ... See ya in another 6 weeks ...

P.S. Culinary School Rocks ... no weak links and no Tad

Have you learned how to prepare weak-a-link stew? Hot and spicey, though can upset the digestion easily.

marc

[deveil]

Dear Mister Moderator . . .

as regards the basic message?
amen.

gary devan

[Tad Eareckson]

Brian,

I don't know if you've taken a look at one of those little color blindness test charts lately but Chris was NOWHERE NEAR the gray layer. He was way down at the bottom of the flaming red zone - as is often the case.

With respect to Matthew... My fuse has gotten pretty short.

In a previous incarnation of this discussion he made the comment:

>
Egads! Popping wink links isn't your only problem.
<

whilst operating under the delusion that weak link rating had something to do with hook-in weight.

You were the one who called him on it - rather too gently, I thought.

That needed to be followed up by an "Oops, sorry 'bout that." It wasn't.

His first contribution to this thread was an out of the blue personal insult. No apology - nor even explanation - there either.

Then repeated multiple misrepresentations of what I had stated despite repeated cautions and requests to actually READ the material upon which he was commenting.

That should have generated another "Oops, sorry 'bout that." but again he continues on as if he's never been capable of error of any kind and has the gall to ask "Do you ever read the stuff you write?".

That's a super strategy if one is running for political office but it's got no place here.

My definition of a moderator is someone who moderates. I didn't request and would (and have) STRONGLY OBJECT(ED) to Mark editing any copy.

As I have said in previous discussions - to little effect - it helps moderation ENORMOUSLY when a third party steps in with a simple intervention like "No, Matthew, that's not what he said. Go back and read what he said." That doesn't have to be Mark - that can be any halfway literate member of the forum.

But it seldom happens, things inevitably degrade, and Mark always winds up having to spend a lot of time threatening the people on the right (me) and clueless (most everyone else) sides of the discussion with expulsion.

My take of the Matthew:Chris ratio is the precise opposite of yours. Chris can be totally ignored - he's relatively harmless. Matthew - although much less overtly malicious - mixes genuine effort and legitimate - although misguided - concerns with negligent disinformation and clouds the issue. He's way more disruptive and dangerous than Chris could ever hope to be.

Easy segue to the "casual reader"...

This discussion concerns a major safety issue. This is no place for no goddam "casual readers". Matthew's casual reading is precisely what got this thread gummed up and gave Chris an opening. I strongly recommend that casual readers stick to weekend flying recaps where they can't do much harm.

This issue of AT weak links is so difficult to understand that - worldwide - the number of hang glider pilots who totally get it would all fit in a Chevy Suburban and still have plenty of room left over for harnesses.

The reason for that is that we got it wrong from Day 1. It's wrong in the books, regs, and training and we're just lately starting to get it right on a rather microscopic level. It's taking a LOT of work though and I don't need any more potholes or speed bumps thrown in my way.

Gary,

Thanks much for your comments - on and off forum.

[brianvh]

Tad;

You are right, in terms of damaging what I believe is your largely correct arguments, Matthew is more dangerous than Chris. But you are asking the "moderator", a volunteer, to perform a highly involved and subtle task. However useful and beneficent it may be, it's asking way too much. Sorry to say, you're on your own until a true conflagaration breaks out. And then Mark's still not compelled to do anything unless he feels like it because he's a volunteer. Let's not make him feel unappreciated by asking too much.

Maybe you'd do better to consider Matthew a worthy opponent to help crystallize your statements for everyone else? I believe Johnson used this approach to push through civil rights. He won over a reluctant congress.

I'm not ready to say you are completely correct until I've gone through the math of lockouts for myself. Then there may be other extreme things like the pilot flying way too high while the tug's release jams so the tug tries to break it by gunning the throttle, etc. The blanket statement that weak links do nothing to protect the pilot may not be strictly correct, just mostly true.

[brianvh]

After some thought and prodding by an anonymous source I want to lay things out as clearly as I can.

1. We definitely want links that will break when there's a sudden snap in tension caused by such non-normal flight scenarios such as the cart getting hung up in a pothole, the tug taking up without taking up slack in the line, or a wing falling off the tug causing it to plummet like a dead weight. In these cases the weak link protects both the pilot and equipment.

2. We would prefer the weak link not break during normal tow forces on a thermally day. This could be dangerous.

3. Tad claims that lockout forces are no larger than normal thermally day tow forces. He claims therefore that the accumulated risk of unneeded weak link breaks during tows outweigh the accumulated risk of the more rare breaks during lockout. He wants to increase the average weak link strength that most heavier pilots use to match that typically used by lighter pilots.

All extraneous statements Tad has made about weak links largely being useless I'll ignore as coming from a mind under duress that hasn't taken the time to qualify blanket statements.

I'm willing to accept his claim that lockout forces are not larger than normal tow forces (but would prefer to verify it myself and this will take time to get around to).

The claim that the accumulated risk of breaks during normal tows are greater than that during lockout is much more subjective, and that's where the argument lies. Is this a fair assessment?

[deveil]

Tad;
. . .asking the "moderator", a volunteer, to perform a highly involved and subtle task. . . it's asking way too much.

agreed. the basic issue is not about the moderator. it's about diversions - which i'll hereafter stop being a part of. all alcoholic/addictive types are doomed if they can't resist that first drink. enablers have their own demons.
garyD

[brianvh]

last emendation: where ever I say lockout, I should add 'or other pilot induced in-flight scenarios'.

[Tad Eareckson]

The writing is getting ahead of me. I'm gonna go ahead and post this which I had ready for Brian's of 03:03:29 and then try to catch up on the rest.

Brian,

I greatly appreciate what Mark has done to keep this wire running. I'm just suggesting that he actually might be able to do less of it by stepping in with a short word before an all out flame war erupts.

But - again - ANYBODY (with half a brain or better) can be an effective volunteer moderator.

Gary thinks I'm a total freakin' asshole. But he also thinks that even a total freakin' asshole deserves to be treated fairly. I'm totally with him on those points. (Even Chris occasionally posts something worth responding to and I recently credited him with being right for a change.)

Six words from a neutral third party just made all the difference in the world. It lets me know that I'm not dealing with a total lunatic asylum and it gives a hint to the aforementioned goddam casual readers that maybe I'm not as totally deranged as is the popular perception.

No way Matthew gets worthy opponent status on anything remotely like the tack he's been on since 2007/07/23.

Yet another example... When anyone with a reasonable understanding of aerotowing reads the trike pilot's account of the Bennett / Del Signore fatalities it's freakin' blindingly obvious / case closed.

Assuming there was something wrong with my assessment a worthy opponent would have read the source material and started punching holes. "OK, so how does that explain this?" Instead I get the vintage Marc sort of response along the lines of "You don't have five thousand hours in tugs and gliders each so you can't possibly be intelligent enough to comment."

There are some people out there who would make worthy opponents but - unfortunately - damn near all of them are already sitting in the Suburban. (I'm actually currently working on one who - I believe - is real close to putting the other foot inside and buckling up.)

You yourself are certainly worthy opponent material. On that note - back to the discussion.

You're making this too complicated.

Let's look at one of Matthew's statements again...

>
If you ever decide to stop using weak links altogether, let me know so I can buy a life insurance policy in your name.
<

and do a substitution:

>
If you ever decide to stop flying with a parachute, let me know so I can buy a life insurance policy in your name.
<

I wouldn't feel particularly safe eliminating either one but, statistically, the odds of Matthew making - rather than losing - anything on the deal are, for all intents and purposes, ZERO.

Now lemme save you a bunch of way-over-my-head math real life data.

On 2005/09/10 behind Sunny at 2400' with the Garmin 76S logging coordinates I got hammered, was rolled rapidly and severely to the right, and lost thirty feet before I was able to work on the problem of getting the bubble back.

I was using what some people are starting to realize was a dangerously understrength weak link - 0.76 Gs. IT DIDN'T BREAK. I released.

Move that scenario down to just off the runway and assume that my adrenalin doesn't kick in any faster and I'm dead. And if I'm dead anyone lighter than me - which is just about everyone - is really dead. And Karen is really really really dead.

Steve Kroop again...

>
A weak link is there to protect the equipment - not the glider pilot.
<

If you persist in using the word "lockout" in a discussion about weak links you're gonna have a hard time understanding them.

On an earlier occasion the same 0.76 G weak link held while I rolled about thirty degrees beyond the placard limitation of my glider. So you can't use the terms "weak link" and "control" in the same sentence either.

The jammed tug release scenario...

A weak link isn't there to allow you to fly with crappy equipment. If you fly with a crappy basetube the weak link isn't going to save you. The same must be assumed with respect to the release.

2000/08/26 - Ralph, at waveoff, can't get the Lookout release he borrowed from you to function. Same flimsy weak link. He STALLED OUT THE DRAGONFLY. Sunny GUNNED THE ENGINE. "This resulted in a SUDDEN AND SEVERE PULL ON THE HARNESS AND GLIDER; I was only able to pull on the release again, WHILE SIMULTANEOUSLY PRAYING FOR THE WEAK LINK TO BREAK."

THE WEAK LINK DIDN'T BREAK!

If you start trying to dumb down the weak link to do a job which it can't do anyway YOU'RE GONNA KILL DANNY.

>
The purpose of a weak link is solely to prevent the tow force from increasing to a point that the glider can be stressed close to or beyond its structural limits.
<

[brianvh]

Based on these situations, the only thing that's causing all these normal flight time weaklinks to break is them getting frayed. I don't believe this because I once broke 5 weak links in a row while trying to learn to tow a K2. One of those may have saved me from a lockout situation, but I'm not sure if in that case I released first or not. I think I did release in that case instead of it breaking. In other tows I felt a bit out of control but not panic stricken enough to release.

Since in 4 out of 5 tows I felt somewhat under control but the link broke, and when I (and Ralph) were out of control it didn't, it seems to back up your argument that weak links don't prevent in-flight incidents. But I don't know if the tug pilot had a very different feeling and was being yanked around by my poor tow technique on that glider.

[Tad Eareckson]

Brian,

The worthy opponent of my dreams. Ahhh...

The cart getting hung up in a pothole. NO. That's gotta be the release.

http://ozreport.com/pub/fingerlakesaccident.shtml

The weak link DOES NOT KEEP THE PILOT FROM GETTING HURT. He's undoubtedly got an understrength weak link but he gets hurt. The weak link only fails AFTER he gets hurt. You could make a weak argument that in the absence of any weak link he's gonna get dragged AFTER he gets hurt but - why bother? There's no freakin' way a 2.0 G weak link is gonna withstand a super power whack like that.

That release configuration, by the way, was no freakin' way in compliance with the SOPs.

The tug taking up slack in the line. Not really. With the glider pointing at the tug any increase in tension isn't gonna last very long. Not much of an issue.

Wing falling off the tug. If you want. I'm probably gonna be able to release 'cause the tug's 250 feet away and that gives me some time.

Point 2. Yeah. We don't want the weak link to break on a thermally day 'cause that's the only sort of day on which we want to be flying. We want to be the ones making that decision and we can virtually always do it faster and better than the weak link. And a weak link that fails in such a manner as to inconvenience everybody at the flight park can also fail in such a manner as to kill you.

Point 3. Yeah, pretty solid. We are not seeing evidence of lighter pilots being injured at a higher rate than heavier ones. We are - in fact - seeing quite the opposite.

Mind under duress... Yeah, totally solid there.

Weak links useless, blanket statements, qualification...

WE DO NEED TO FLY WITH WEAK LINKS - BUT...

In the entire history of Ridgely flight ops there would have been no negative consequences if we hadn't.

Just as if - for non aerobatic flights - there would have been no negative consequences to anyone flying without a parachute.

There is a point at which a light weight weak link becomes DANGEROUS. That point has been defined by the FAA and other folk who tend to have their shit together as 0.8 Gs.

We have been flying weak links which are - in effect - as low as 0.4 Gs, i.e., HALF OF WHAT THEY SHOULD BE and there is absolutely no question that they ARE making things more dangerous.

We should be not be hugging that lower limit and we have no need to push the upper. Karen is in the right ballpark at 1.22 and has no problems. If she flies in the middle of the safety range - at 1.40 - I predict she will have even less than no problems.

>
I'm willing to accept his claim that lockout forces are not larger than normal tow forces (but would prefer to verify it myself and this will take time to get around to).
<

Again. Skip the math. Just look at the flight reports. When are we having weak link breaks and when aren't we? I'll save you the trouble. We're having them when we don't want them and not having them when we do.

>
The claim that the accumulated risk of breaks during normal tows are greater than that during lockout is much more subjective, and that's where the argument lies. Is this a fair assessment?
<

No. This is not subjective. We've got TONS of data. I'm still looking of JUST ONE positive weak link break with no asterisks. I'm having much better luck with my Sasquatch hunt.

Oops, yet another post on which to catch up.

I'm not sure where the getting frayed thing came from but, to some extent, yeah. But not necessarily 'cause they're being used for multiple flights. Virgin weak links often break right off of the cart. Safe working load thing.

http://ozreport.com/forum/viewtopic.php?t=13573

If a weak link breaks and saves you from a lockout situation it's dumb luck. It can never be counted on to break until you're well into a lockout situation. And if you happen to be low at the time things are already potentially lethal.

If the tug pilot doesn't like what's going on at the back end of the string he never has to wait for the weak link to kick in - and, at launch, can't afford to.

P.S. I don't think you CAN learn to tow a K2.