Weak links

General discussion about the sport of hang gliding
Zack C
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Re: Weak links

Post by Zack C »

Tad Eareckson wrote:Where'd the post go? Who's aglia? You got the original?
Aglia apparently deleted it while I was writing a response. I deleted my post shortly after making it when I realized his post was gone since it was a reply to a non-existent post. I then sent the same response to aglia privately since I already wrote it.

Aglia is a pilot from San Antonio and a member of our aerotow club. He wasn't interested in learning from you, but maybe he'll learn from me.

I still had his post cached in my browser:
If it's strong enough to get you to altitude, it's strong enough to permit a very bad attitude that could be catastrophic near the ground.
Zack, pardon my dumb questions. Please help me be clarified. Are you saying a strong weaklink delays the occurence of a lock out. or is it there to prolong the lock out to give you time to release? HOw? Does one gain altitude when he/she is in a lock out (me thinks no so I think it won't matter if you have a strong weak link during a lock out)? cheers
Zack
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

He probably figured out that he was learning stuff from you that you had learned from me.
I wouldn't have deleted the post. It's not your job to preserve continuity based upon what somebody else does to the record.
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

Zack C - 2012/08/18 16:33:27 UTC

Nothin' in the SOPs about 130 or Greenspot!
Yeah there is.
Federal Aviation Administration - 2004/07/27
Title 14: Aeronautics and Space
PART 91-GENERAL OPERATING AND FLIGHT RULES
Subpart D-Special Flight Operations
Section 91.309
- Towing: Gliders and unpowered ultralight vehicles.

(a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless-

- (1) The pilot in command of the towing aircraft is qualified under Section 61.69 of this chapter;

- (2) The towing aircraft is equipped with a tow-hitch of a kind, and installed in a manner, that is approved by the Administrator;

- (3) The towline used has breaking strength not less than 80 percent of the maximum certificated operating weight of the glider or unpowered ultralight vehicle and not more than twice this operating weight. However, the towline used may have a breaking strength more than twice the maximum certificated operating weight of the glider or unpowered ultralight vehicle if-

-- (i) A safety link is installed at the point of attachment of the towline to the glider or unpowered ultralight vehicle with a breaking strength not less than 80 percent of the maximum certificated operating weight of the glider or unpowered ultralight vehicle and not greater than twice this operating weight;

-- (ii) A safety link is installed at the point of attachment of the towline to the towing aircraft with a breaking strength greater, but not more than 25 percent greater, than that of the safety link at the towed glider or unpowered ultralight vehicle end of the towline and not greater than twice the maximum certificated operating weight of the glider or unpowered ultralight vehicle;


- (4) Before conducting any towing operation within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport, or before making each towing flight within such controlled airspace if required by ATC, the pilot in command notifies the control tower. If a control tower does not exist or is not in operation, the pilot in command must notify the FAA flight service station serving that controlled airspace before conducting any towing operations in that airspace; and

- (5) The pilots of the towing aircraft and the glider or unpowered ultralight vehicle have agreed upon a general course of action, including takeoff and release signals, airspeeds, and emergency procedures for each pilot.

(b) No pilot of a civil aircraft may intentionally release a towline, after release of a glider or unpowered ultralight vehicle, in a manner that endangers the life or property of another.

[Doc. No. 18834, 54 FR 34308, 1989/08/18, as amended by Amdt. 91-227, 56 FR 65661, Dec. 17, 1991; Amdt. 91-282, 69 FR 44880, 2004/07/27]
So as of 2004/07/27 there's an FAA regulation which - for the first time in the history of hang gliding anywhere - establishes a minimum weak link rating - which, for all intents and purposes - is considerably higher than idiot USHGA's original MAXIMUM weak link rating - makes it illegal for me and every heavier solo to fly two point on that damnable piece of fishing line.

And when you consider that it blows left and right all the time on light medium gliders straight and level in smooth air at around 125 pounds towline it really outlaws it for everybody.

But nobody tells me - a dues paying, magazine receiving, rated and active AT pilot - and Ridgely Greenspot hell continues unabated for me and everyone else trying to get to the front of the line and release altitude.

On 2005/09/03 Jeremiah Thompson - along with his idiot "instructor" - dies behind an idiot high tug with an idiot low - and clearly illegal - weak link.

On 2005/10/05 his family files suit against Hang Glide Chicago but there's a whitewash/coverup and the suit is dropped.

On 2006/03/15 the slimeballs at USHGA - 'cause they know they've got a serious liability problem - issue a bullshit ass covering "safety" advisory:

http://www.ushpa.aero/advisory.asp?id=1

with a mild suggestion that...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links
Jim Rooney - 2007/08/01

Whatever's going on back there, I can fix it by giving you the rope.

It's more of this crappy argument that being on tow is somehow safer than being off tow.
...not every problem behind the tug can be most effectively fixed by the asshole up front handing the glider the rope - but going to great conspicuous pains to omit any mention of the weak link which triggered the two hundred foot plummet.

Fortunately for all the Flight Park Mafia whatever's-going-on-back-there-I-can-fix-it-by-giving-you-the-rope assholes, however, this advisory includes a clause which states that...
Understand that we are not asking if you agree with the safety notice, but that you have read it and understand what it says.
...the participant need not accept USHGA's perception that a mushing glider can go down like a fucking brick...
Wills Wing / Blue Sky / Steve Wendt / Ryan Voight Productions - 2007/03

NEVER CUT THE POWER...

Image

Reduce Gradually
Increase Gradually
...if the power is abruptly cut, that USHGA has the highest respect for the opinions of its rated pilots, and that if one believes that whatever's going on back there can be fixed by the gift of the rope then that decision will be fully honored - and defended in court by USHGA's lawyer / fatality report screener.

It took me until November of that year to stop being a 130 Pound Greenspot Zombie (even though I had debunked the 260 pound / position-the-knot-so-that-it's-hidden-from-the-main-tension-in-the-link-and-excluded-altogether-from-the-equation crap several years earlier).

Started the jihad the following season - 2007.

On 2009/02/11 then Towing Committee Chairman Gregg Ludwig, who's figured out that I know what I'm talking about on weak links, foolishly asks me to help him revise the AT SOPs to something safe and sane.

On 2009/05/09 - well over a month after the Towing Committee motherfuckers have totally ignored my months of work on the revision at the 2009/03/27-28 BOD meeting and haven't even done me the courtesy of telling me they haven't even bothered to read my revision - I start going into whistleblower mode and USHGA starts doing some major worrying about all the shallow graves out back.
Nobody - 2012/05/31 11:17:01 UTC

Take look at the June issue of the USHPA magazine. You'll find thirteen poorly written and confusing pages of weak link mumbo jumbo written by Drs. Lisa Colletti and Tracy Tillman.

Also included in the article- five photos, four bar graphs and eighteen references.

I suspect the article is an attempt to provide flight park operators and USHPA with justification and ammunition in a legal case filed against them.
In the 2012/06 issue of Hang Gliding magazine Drs. Lisa Colletti and Tracy Tillman publish a load of absolute crap about weak links - including 260 pound single loops of 130 pound Greenspot - in an effort to provide flight park operators and USHPA with justification and ammunition in the event a legal case filed against their criminally negligent asses.
Dr. Trisa Tilletti - 2012/06

I'll start with a legal review. The FAA has mandated requirements for weak links in FAR 91.309(a)(3) for civil aircraft towing sailplanes, ultralight gliders, and hang gliders in the US.
Zack C - 2012/06/02 02:20:45 UTC

It's news to me that FAR 91.309 applies to hang gliders, but sure enough, that appears to be the case. 'Unpowered ultralight vehicle' was added to the regulations in September of 2004.
Eight years after the fact this is the first ANYBODY hears that we're supposed to be operating under sailplane regulations.

So about three weeks after Dr. Trisa Tilletti has softened the crap out of everyone's brain with their bullshit article they publish the latest set of their bullshit SOPs.
The United States Hang Gliding and Paragliding Association, Inc. - 2012/06/20
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
12. Hang Gliding Aerotow
-C. USHPA Aerotow Equipment Guidelines
So everything following covering all of the equipment is a GUIDELINE - not an actual REGULATION. 'Cause everybody knows that regulation stifles the kind of innovation that we get from all the tow parks - who've devoted tremendous resources towards perfecting aerotowing for almost twenty years - and gifted and talented individuals like Bob Kuczewski.
04. Weak links must be used in accordance with 14 CFR 91.309(a)(3).
Well, not really MUST. We are talking GUIDELINES here.
USHPA recommends that a nominal 1G (combined operating weight of the glider and pilot) weak link be used, when placed at one end of a hang glider pilot's V-bridle; or about 1.5-2G if placed at the apex of the tow bridle or directly in-line with the tow rope.
WHAT THE FUCK KINDA SENTENCE IS THAT? You've gotta read it about twenty times to even get some vague idea of what was going on in the author's deranged mind.
USHPA recommends...
- Who the hell is "USHPA"?

- Upon WHAT is that idiot recommendation based? A nice round number that Donnell pulled out of his ass thirty-two and a half years prior under the idiot assumptions that it would prevent lockouts and stalls?
...that a nominal 1G...
Fuck nominal, de jure and de facto weak links. Sailplanes have done just fine without Tilletti mumbo jumbo bullshit weak links - so can we.
...(combined operating weight of the glider and pilot) weak link be used...
Fuck the combined operating weight of the glider and pilot.

- There's also a harness, parachute, helmet, clothing, instruments, water, packing gear... to consider.

- Weak links aren't about flying weights. Weak links are about glider capacities. Any asshole who talks about flying weights is trying to use weak links as lockout preventers or limiters.

- Take a minimally loaded Sport 2 155 - flying weight 210 pounds - USHGA recommended weak link 210 pounds. Max certified operating weight is 310 pounds. Minimum FAA legal weak link 248 pounds. So USHGA's recommendation is that you violate the FAA minimum by 38 pounds, that you fly at 0.68 percent of max certified operating weight. But that's OK... We're just really talking about guidelines, recommendations, opinions here.
...when placed at one end of a hang glider pilot's V-bridle;
The fucking FAA regulation doesn't say to put the fucking weak link at ONE end of the fucking hang glider pilot's V - by which Dr. Trisa Tilletti means two point - bridle. The fucking FAA regulation says:
A safety link is installed AT THE POINT OF ATTACHMENT OF THE TOWLINE TO THE GLIDER...
There's a reason it doesn't say to put it at ONE end of the hang glider pilot's V-bridle:
Towing Aloft - 1998/01

I witnessed a tug pilot descend low over trees. His towline hit the trees and caught. His weak link broke but the bridle whipped around the towline and held it fast. The pilot was saved by the fact that the towline broke!
It's so that on the extremely rare occasion on which you actually NEED the fucking weak link you actually HAVE the fucking weak link.

You can accomplish that by following the fucking regulation and putting the goddam weak link at the point of attachment of the towline to the glider's bridle, WHICH NOBODY DOES, or - like I said in the magazine over fifteen years ago and wrote into my SOPs proposal - treat the bridle as an extension of the towline, put a compliant weak link on the top end, and put something heavier but under two Gs BELOW the tow ring.

But, since this concept is miles above the comprehension level of Dr. Trisa Tilletti...

http://groups.yahoo.com/group/skysailingtowing/message/549
Weaklinks/bridles; was: high wire act world news
Dr. Trisa Tilletti - 2001/05/16 15:14:55 UTC

We (and many others) do not recommend using a second weaklink on the non-released end of the bridle. That weaklink is just as likely to break as the one on the other end. If the lower weak link breaks, the bridle could get caught in the towline ring, and pull the glider from the 'biner or keel, causing it to tuck. The other weaklink (on top) may not break prior to the tuck.

The weaklink should be on the released end of the bridle, and the bridle should release from the top. That way, if the bridle does get caught on the ring, it is pulling from the body, rather than from the glider, and the glider may still be controllable--in which case you can use your secondary release (or hook knife if that fails) to release.
...(and many others) they just tell you to go ahead, violate the FAA regulations, and configure such that the focal point of a safe towing system is, when using Industry Standard equipment, taken out of the equation...

http://www.hanggliding.org/viewtopic.php?t=14230
pro tow set-up
Jim Rooney - 2009/11/02 18:58:13 UTC

Oh yeah... an other fun fact for ya... ya know when it's far more likely to happen? During a lockout. When we're doing lockout training, the odds go from 1 in 1,000 to over 50/50.
...over half the time in the situations in which it's most needed.

It's EXACTLY like Steve Seibel's idiot fucking Wallaby Release:

http://www.hanggliding.org/viewtopic.php?t=26870
weak links
Steve Seibel - 2012/08/18 16:22:36 UTC

The high G-load made it harder to for me to get my hand quickly to the release, and the glider rolled to quite a steep bank, and the loads rose much higher than I intended before I hit the handle.
Dr. Trisa Tilletti and the rest of the Flight Park Mafia just LOVE configuring things such that the more one's life is dependent upon a piece of equipment the more it's likely it is to become inoperable and/or taken out of the equation altogether. I one hundred percent guarantee you that if these assholes designed the landing lights systems for conventional aircraft they'd be solar powered.
...or about 1.5-2G if placed at the apex of the tow bridle or directly in-line with the tow rope.
Or about one and a half to two Gs if configured in compliance with the FAA regulation. Or, if you put a:
- 0.8 G weak link at the end of the towline, 0.8 Gs
- 1.0 G weak link at the end of the towline, 1.0 Gs
- 1.2 G weak link at the end of the towline, 1.2 Gs
- 1.4 G weak link at the end of the towline, 1.4 Gs

Thanks, Trisa, I think I'm starting to understand this concept.
The actual strength of the weak link used by the hang glider pilot must be appropriate for the operation and have a breaking strength between 80% and 200% MCOW (max. cert. operating weight) of the glider, in terms of direct towline tension.
Right, Trisa. 'Cause, at different operations gliders have different load capacities. Same way...

http://groups.yahoo.com/group/skysailingtowing/message/4592
Weaklinks
Tracy Tillman - 2005/02/08 19:16:10 UTC

The sailplane guys have been doing this for a long time, and there are many hang glider pilots and quite a few tug pilots who don't understand what the sailplane guys have learned over the years. It certainly would help if hang glider towing methods and training were standardized to the degree that they are in the sailplane world.
...it works for different sailplane operations.

At the Columbus operation...

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Zack C - 2011/08/31 17:38:50 UTC

And not everyone tows at flight parks. At our local club, I use a 1.3 G weak link and the tug uses a ~600 lb one. I'm quite happy with that arrangement.
...1.3 Gs is appropriate and everybody's quite happy.

At a Flight Park Mafia operation...

http://ozreport.com/12.081
Weaklinks - the HGFA rules
Davis Straub - 2008/04/22 14:47:00 UTC
Pilots must use weaklinks provided by the meet organizers and in a manner approved by the meet organizers. All weaklinks will be checked and use of inappropriate weaklinks will require the pilot to go to the end of the launch line to change the weaklink.

Weaklinks will consist of a single loop of Cortland 130 lb Greenspot braided Dacron Tolling line and should be placed at one end of a shoulder bridle.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links
Jim Rooney - 2007/07/19 14:50:52 UTC

And yes, get behind me with a "strong link" and I will not tow you.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
Jim Rooney - 2008/11/24 05:18:15 UTC

I've personally refused to tow a flight park owner over this very issue. I didn't want to clash, but I wasn't towing him. Yup, he wanted to tow with a doubled up weaklink. He eventually towed (behind me) with a single and sorry to disappoint any drama mongers, we're still friends. And lone gun crazy Rooney? Ten other tow pilots turned him down that day for the same reason.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links
Jim Rooney - 2007/07/22 22:30:28 UTC

Hahahahahahahahaha
Oh that's just rich!
Riiiiiight... it's my attention span at issue here....
and I'm the one that's arrogant!
HAHAHAHAHAHAHAAHAHA

No, I'm not being nice. No, I do not feel the need to be nice. You're trying to convince people to be less safe. I don't want to be on the other end of the rope when someone listening to this drivel smashes in.

I've heard it a million times before from comp pilots insisting on towing with even doubled up weaklinks (some want no weaklink). I tell them the same thing I'm telling you... suck it up. You're not the only one on the line. I didn't ask to be a test pilot. I can live with your inconvenience.

Please tell me again what's wrong with the wheel? Why you keep trying to reinvent it?
...THE weak link that's appropriate for the operation and has a breaking strength between 80% and 200% MCOW (max. cert. operating weight) of the glider, in terms of direct towline tension - at the sole discretion of the tow park operator, meet director, tug driver, or cabal of tug drivers - is, as it's ALWAYS BEEN and ALWAYS WILL BE, the loop of 130 pound Greenspot that...
This article was peer-reviewed and approved for publication by the USHPA Towing Committee.
...Dr. Trisa Tilletti, the USHPA Towing Committee, the editor of Hang Gliding magazine, and the USHPA Board of Directors...
Based on several decades of experience and hundreds of thousands of tows conducted by numerous aerotow operators across the county, the de facto standard has become use of a 260 lb. weak link made as a loop of 130 lb. green spot IGFA Dacron braided fishing line attached to one end of the pilot's V-bridle.
...have all certified as having a breaking strength of 260 pounds - pretty much around the middle of the FAA legal range for most solo gliders.

And, as it's ALWAYS BEEN and ALWAYS WILL BE, if you've got bench test data showing the loop of 130 pound Greenspot blows at around 130 pounds, puts you off the bottom of the FAA legal range, and has a high probability of dropping you back on the launch cart and wanna fly something that ACTUALLY blows at 260 pounds, you can go fuck yourself 'cause...
Dr. Trisa Tilletti - 2012/06

We could get into details of lab testing weak links and bridles, but this article is already getting long. That would be a good topic for an article in the future. Besides, with our backgrounds in formal research, you and I both know that lab tests may produce results with good internal validity, but are often weak in regard to external validity--meaning lab conditions cannot completely include all the factors and variability that exists in the big, real world.
...your data has shit in the way of external validity and cannot completely include all the factors and variability that exist in the big, real world of aerotowing from several decades of experience and hundreds of thousands of tows conducted by numerous aerotow operators across the county.

If you want your odds of clearing the runway to be a little better than...

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Davis Straub - 2011/08/26 14:04:52 UTC

We had six weaklink breaks in a row at Zapata this year.
...zero out of six...
Russell Brown (tug pilot, tug owner, Quest Air owner) said go ahead and double up (four strands of Cortland Greenspot).
...maybe you can get a green from the de facto FAA official to fly within the lower third of the legal range, without - if you're lucky - having to promise to suck his dick after you get your glider put away for the day.

But, of course, DO make sure you always inform him when you're exercising this privilege...
He knows I used his Zapata weaklink in Big Spring (pilots were asked to tell the tug pilot if they were doing that).
...so that he can adjust his flying such that it's less likely to put you into a lockout or swap his weak link down to make sure the tow tension never exceeds his comfort level (solo - single loop, tandem - double loop).
The weak link used at the tow plane end of the towline must be stronger, but not more than 25% stronger, than the strength of the weak link used at the glider end of the towline.
Yeah.

http://ozreport.com/5.126
Flytec Dragonfly
USAFlytec - 2001/07/14

Steve Kroop - Russell Brown - Bob Lane - Jim Prahl - Campbell Bowen

The tail section of the Dragonfly is designed so that it can accept in-line as well as lateral loads. Furthermore the mast extension, which is part of the tow system, is designed to break away in the event of excessive in-line or lateral loads. The force required to cause a breakaway is roughly equivalent to the force required to break the double weaklink used on the tail bridle.
http://www.questairforce.com/aero.html
Aerotow FAQ
Quest Air Hang Gliding

For tandems, either two loops (four strands) of the same line or one loop of a stronger line is usually used to compensate for nearly twice the wing loading.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
Jim Rooney - 2008/11/24 18:54:27 UTC

I'm confused. I never said the tug's ass was endangered. That's why we use 3strand at the tug's end. Using 4 strand can rip things off (it's happened).
http://groups.yahoo.com/group/skysailingtowing/message/4633
Weaklinks and aerotowing (ONLY)
Steve Kroop - 2005/02/10 04:50:59 UTC

On the tow plane we use 1-1/2 loops (3 strands) of 130# line.
Jim Rooney - 2008/11/20 22:25:38 UTC

Something to bear in mind... the tug's weaklink is three strand.

For clarity... A normal single loop weaklink would be considered two. A tandem double loop is considered four.

In the tandem setup, the "weaklink" in the system is at the tug end, not the glider.

Ya'll seem to be missing this.
Once you go beyond three strand... you're not using a weaklink. If the weaklink goes, you're getting the rope.
Paul found this out the hard way in Texas.

Theory's wonderful and all, but reality is not forgiving.
Ask yourself... are you willing to bet your life on your theory?
Dress accordingly.
Jim Rooney - 2008/11/23 19:42:44 UTC

The tug uses 3 strand and so all this talk about using a stronger one is academic.
You don't get to have one that's equal or stronger.

See we've got a system that has an extremely solid track record.
Jim Rooney - 2008/11/23 22:28:30 UTC

If you can find one, more power to you.

Just keep in mind if you do, you need to be weaker than the tug's link... not equal to. You will need to talk it over with any tug pilot that you tow behind. Anything less is unethical. And just as you have the right to refuse a tow from any tugger, they have the right to refuse to tow you... for any reason what so ever.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3648
Oh no! more on weak links
Carlos Weill - 2008/11/30 19:24:09 UTC

The tug weak link broke off at 1000ft, in less than a second the glider was at 500ft.
Right.
06. The purpose of the weak link is to protect the tow equipment, and may not prevent lockouts or other abnormal flight conditions.
What else may it not do, Trisa? May it not prevent:
- injury beyond:
-- four broken ribs and a larynx after a blown dolly launch?
-- a broken shoulder and bashed up face after you snap off a dolly wheel in a hole in the Florida Ridge runway?
- one from having a glider destroyed and/or being paralyzed from the neck down if the tug driver doesn't notice that he's being dragged?
- the wings from being torn off the glider when one slams into the propwash of a 914 Dragonfly after a Mach 5 takeoff?

But it OCCASIONALLY WILL prevent lockouts and other abnormal flight conditions - just as it OFTEN WILL prevent successful launches, straight and level flight in turbulent and smooth air, and any chance of survival for a low glider going into a steep climb.

So because it MAY prevent lockouts or other abnormal flight conditions, especially for total assholes...

http://www.hanggliding.org/viewtopic.php?t=26870
weak links
Steve Seibel - 2012/08/18 16:22:36 UTC

The high G-load made it harder to for me to get my hand quickly to the release, and the glider rolled to quite a steep bank, and the loads rose much higher than I intended before I hit the handle.
...who use total shit for equipment, the actual APPROPRIATE strength of the weak link used by the hang glider pilot will be determined by the operation to be...
Lockout Mountain Flight Park - 2009/07/12

The new GT aerotow release, new as of July 11th 2009, is designed to be used with a V bridle and a 130-pound green stripe Dacron tournament fishing line weak link. At this time it is not recommended to use this release with a higher value weak link. We are confident that with an ultimate load of 130 pounds at the release point, the new GT aerotow release works better than all cable releases that we have experience with.
...that of a single loop of 130 pound Greenspot (at this time).
Nothin' in the SOPs about 130 or Greenspot!
EVERYTHING in this despicable fraud, manipulation, and abuse of power...

http://groups.yahoo.com/group/TUGS/message/1184
aerotow instruction was Re: Tug Rates
Larry Jorgensen - 2011/02/17 13:37:47 UTC

It did not come from the FAA, it came from a USHPA Towing Committee made up of three large aerotow operations that do tandems for hire.

Appalling.
...is about maintaining the ability to force gliders up on 130 pound Greenspot, keep the Dragonflies on triple-strand to protect their tow mast breakaways, and keep the Towing Committee Chairmen, tow park operators, tug drivers, tandem instructors, and excellent book authors from having to admit that they're all a bunch of brain dead, incompetent, gutless, corrupt, evil, lying, criminally negligent, serial killing shits.
Zack C
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Re: Weak links

Post by Zack C »

Tad Eareckson wrote:Take a minimally loaded Sport 2 155 - flying weight 210 pounds - USHGA recommended weak link 210 pounds. Max certified operating weight is 310 pounds. Minimum FAA legal weak link 248 pounds. So USHGA's recommendation is that you violate the FAA minimum by 38 pounds, that you fly at 0.68 percent of max certified operating weight.
Tad, I don't think you understand the recommendation. They're saying the actual weak link breaking strength should be 210 lbs. At the end of a two-point bridle that will allow a towline tension of 365 lbs. That's 1.18 times the MCOW.

We've discussed this before, but I think the idea behind the whole 'nominal 1G' thing is that it spares the pilot from having to compute anything. 'Nominal 1G' is, for most pilots and gliders, going to be somewhere in the middle of the FAA's mandated range. That's why I'm telling people to follow USHPA's recommendation.

Yeah, I don't get the 'appropriate for the operation' BS but it's immediately followed by 'must...have a breaking strength between 80% and 200% MCOW', so it doesn't bother me that much.

I think you're being way too cynical. We now have the FAA regs mentioned in the USHPA magazine, explicitly in the SOPs, and implicitly as USHPA's official recommendation. This is better than I could have ever hoped.

'Trisa'...I like that.

Zack
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Tad Eareckson
Posts: 9161
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Re: Weak links

Post by Tad Eareckson »

Tad, I don't think you understand the recommendation.
I'm pretty sure NOBODY does - including/especially the authors.
They're saying the actual weak link breaking strength should be 210 lbs.
Or, should you happen to fall at the other end of the spectrum, 310 pounds.
At the end of a two-point bridle that will allow a towline tension of 365 lbs.
At the end of a one point bridle that will allow a towline tension of 620 pounds.
That's 1.18 times the MCOW.
That's 2.00 times the moocow.

That's a pretty generous range to be RECOMMENDING for a single glider model - especially when one of the goons undoubtedly behind this rubbish is selling the best two point release in The Industry and telling everyone (after purchase) not to use a weak link more than 42 percent of USHGA's recommended nominal one G weak link at that point.

Yeah, you're right about the intent being to stick the 210 pound weak link on the two point bridle. But this "nominal one G weak link" bullshit traces back to their idiot magazine article in which they reveal that they're under the impression that some long forgotten wise old aerotowing gurus recommended a weak link equal to flying weight for some rational reason when - in fact - it's just a nice round number that Donnell pulled out of his ass in 1980 on the assumption that in would serve as a lockout preventer and let him survive using the lunatic crap he assembled from the local hardware store for eight and a half bucks and designated as a release system.
We've discussed this before, but I think the idea behind the whole 'nominal 1G' thing is that it spares the pilot from having to compute anything.
- Yeah, dontchya miss the good ol' days when you just walked out to the flight line, got handed a loop of 130 pound Greenspot, and got told to Double Lark's Head it onto your one or two point bridle such that the knot was positioned to be hidden from the main tension in the link and excluded altogether from the equation so that you'd have the full 260 pounds, the flying weight of an average glider - thus about one G, a good rule of thumb which would keep you from getting into too much trouble?

- It would also probably be a good idea to design cars such that everyone could use octane, brake fluid, oil, tire pressure ratings of one.

- So how you've gotta have extensive ground school and testing to get sailplane ratings - but for hang gliders, which are a hundred times more difficult and dangerous to tow, it's considered an unacceptable burden to insist that the pilot run a grade school math problem once per glider purchase?

- You've just been dealing with the likes of Paul Hurless, Craig Hassan, and Kinsley Sykes. How many total morons who can't handle any numbers more complicated than one - at best - do you think this sport really needs?

-

150 - 225 - 129 - 113
175 - 263 - 151 - 131
200 - 300 - 173 - 150
225 - 338 - 194 - 169
250 - 375 - 216 - 188
275 - 413 - 237 - 206
300 - 450 - 259 - 225
325 - 488 - 280 - 244
350 - 525 - 302 - 263
375 - 563 - 323 - 281
400 - 600 - 345 - 300
425 - 638 - 367 - 319
450 - 675 - 388 - 338
475 - 713 - 410 - 356
500 - 750 - 431 - 375
525 - 788 - 453 - 394
550 - 825 - 474 - 413
575 - 863 - 496 - 431
600 - 900 - 518 - 450

Column 1 is moocow.
Column 2 is 1.5 Gs / towline weak link.
Column 3 is two point bridle end weak link.
Column 4 is one point / secondary bridle end weak link.

Put THAT in the fucking SOPs and/or Guidelines instead of the rot that's in there now. Then somebody who graduated from the second grade could just look at it and tell Paul, Craig, and Kinsley which pieces of fishing line they should be using and where to put them.
'Nominal 1G' is, for most pilots and gliders, going to be somewhere in the middle of the FAA's mandated range. That's why I'm telling people to follow USHPA's recommendation.
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Kinsley Sykes - 2011/08/31 11:35:36 UTC
Zack figured it out.
Well actually he didn't. But if you don't want to listen to the folks that actually know what they are talking about, go ahead.
Feel free to go the the tow park that Tad runs...
How many people do you think are actually doing it and how many people are continuing to listen to the folks who actually know what they are talking about?

- We can't get aeroexperiments to change his string to something that won't blow up in his face or spend fifty bucks for a Street Release to keep him from getting killed for real down low the way he's been killed for the purpose of the exercise at altitude half a dozen times already 'cause he's busy telling everybody how to retrofit their gliders with rudders.

- The thread appears to be dead and is real close to drifting into archive pages obscurity.

- Paul Edwards is your best bet. We are SO fragile over here. It's so much more rewarding to be engaging someone and know you're getting through just a little bit instead of doing repetitive monologues 99 percent of the time and praying for the hit counters to creep up a little.
Yeah, I don't get the 'appropriate for the operation' BS...
It's OBVIOUS code for Greenspot. The flight parks have enough of it stockpiled to wind around the Earth at its equator twenty times. And 95 percent of our Dragonfly drivers would sooner take off with broken aileron control linkage and water in their fuel lines than allow a solo glider to get behind them with a loop of 135 pound test fishing line.
...but it's immediately followed by 'must...
With each flight, demonstrates a method of establishing that the pilot is hooked in just prior to launch.
...have a breaking strength between 80% and 200% MCOW', so it doesn't bother me that much.
Lemme know the next time you get behind a Dragonfly confident that if the shit hits the fan you won't be getting the rope - one way or another.
I think you're being way too cynical.
Zack C - 2012/08/02 01:30:21 UTC

LOL...you are a prophet.
Nobody - 2012/05/31 11:17:01 UTC

I suspect the article is an attempt to provide flight park operators and USHPA with justification and ammunition in a legal case filed against them.
Steve ABSOLUTELY NAILED IT. You don't get rot that outrageous just on the basis of stupidity alone. This has been engineered. I've analyzed the hell out of every comma these motherfuckers have put in print and I know EXACTLY what they're doing, why, and how they're trying to accomplish their goals.

That article and that SOPs revision was an OBVIOUS counterattack to my efforts to get the SOPs revised and the FAA to do something to get us to follow something in the ballpark of our own goddam rules. I'm referenced in that idiot article three times and the idiot weak link SOPs are a condensation of the idiot article.

Likewise this USHGA video:

http://www.youtube.com/watch?v=VW8qZESnFvQ


...is USHGA's lawyer's response to the "Failure To Hook In"...

http://www.kitestrings.org/post2087.html#p2087

http://groups.yahoo.com/group/hhpa/message/11361
Question
Zack C - 2010/10/15 13:25:50 UTC

Speaking of which, while I can fault Tad's approach, I can't fault his logic, nor have I seen anyone here try to refute it.
...article I submitted to the magazine a bit under three years ago.

Anything has a solid foundation of numbers and logic in this sport, USHGA's gonna spare no effort in attempts to hunt it down and kill it.
Zack C - 2012/06/02 02:20:45 UTC

I just cannot fathom how our sport can be so screwed up.
These assholes and their strategies and tactics are why.
We now have the FAA regs mentioned in the USHPA magazine, explicitly in the SOPs, and implicitly as USHPA's official recommendation. This is better than I could have ever hoped.
You getting halfway through to Paul Edwards was more important. That's the only way ANYTHING is gonna be accomplished. We need to keep finding people capable of actual thought processes and consolidating them and ripping the Paul Hurlesses, Craig Hassans, and Kinsley Sykesses to shreds. Keep pushing as much as you think you can afford to.
'Trisa'...I like that.
Hey! What about "Tilletti"? The names merge and blend as seamlessly as their words, brain waves, lies, and DNA sequences.
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

From Page 56 of the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden, Reference 4 for Dr. Trisa Tilletti's 2012/06 landmark article on weak links:
Towing Aloft - 1998/01

Safety Tip: The only way to insure safe, consistent weak links is to test each batch of new weak link material with the same equipment (release, rings, bridles, etc) for breaking strength.
But hey, that's old school. Based on several decades of experience and hundreds of thousands of tows conducted by numerous aerotow operators across the county it has been realized that bench testing to determine weak length strength is totally useless because...
Dr. Trisa Tilletti - 2012/06

We could get into details of lab testing weak links and bridles, but this article is already getting long. That would be a good topic for an article in the future. Besides, with our backgrounds in formal research, you and I both know that lab tests may produce results with good internal validity, but are often weak in regard to external validity--meaning lab conditions cannot completely include all the factors and variability that exists in the big, real world.
...the results have absolutely no external validity.

New school is to take a length of 130 pound Greenspot, install it on a bridle in some clever way that positions the knot so that it's hidden from the main tension in the link and excluded altogether from the equation better than someone else's clever way that positions the knot so that it's hidden from the main tension in the link and excluded altogether from the equation, declare its strength to be 260 pounds (the perfect rating for just about any glider you wanna name), and force everybody to use it for a couple of decades.

But back to the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden, Reference 4 for Dr. Trisa Tilletti's 2012/06 landmark article on weak links, Page 59:
For aerotowing operations, a weak link breaking strength equal to 80 to 100% of the total flying weight--the weight of the pilot and glider--is a reasonable starting point. This will typically be in the neighborhood of 200 to 250 pounds. With the common aerotow bridle that has a weak link at the end, about half these values is a proper weak link strength. A common weak link in this case is a loop of 130 lb test braided fishing line or a loop of 205 leech line with an overhand knot in it to weaken it. These weak links break around 120 lbs due to the knots and effect of rings or releases. When placed at the end of a V bridle it gives a tow breaking point of 240 pounds.
So...

- This tested value is probably a bit off 'cause it's only 46 percent of Trisa's assumed value - which has really excellent external validity.

- In order for a 120 pound weak link on the end of a two point bridle to give a tow breaking point of 240 pounds the apex angle would need to be zero degrees. And that would necessitate use of an infinitely long bridle - which would be a real bitch to stow after release.

- This is a little confusing 'cause on Page 57 of the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden, Reference 4 for Dr. Trisa Tilletti's 2012/06 landmark article on weak links there's a Figure 2-19 showing the Effect of Bridle Length on Weak Link using - if you do the trig 'cause they don't bother to tell you - an apex angle of 51 degrees. The load on the weak link is eleven percent over half towline.
Dr. Trisa Tilletti - 2012/06

What we have covered in this article is practical information and knowledge gleaned from the real world of aerotowing, developed over decades and hundreds of thousands of tows by experts in the field. This information has practical external validity.
So let's go to one of the experts in the field of the real world of aerotowing, whose procedures, such as omitting glider end weak links from tandem flights, and equipment, such as the new GT aerotow release which works better than all cable releases that they have experience with at an ultimate load of 130 pounds at the release point at this time, were developed over decades and hundreds of thousands of tows.
Lockout Mountain Flight Park - 2009/07/12

The new GT aerotow release, new as of July 11th 2009, is designed to be used with a V bridle and a 130-pound green stripe Dacron tournament fishing line weak link. At this time it is not recommended to use this release with a higher value weak link. We are confident that with an ultimate load of 130 pounds at the release point, the new GT aerotow release works better than all cable releases that we have experience with.

We recommend the green stripe 130-pound test tournament fishing line. Our tests have shown that when tied properly this line breaks consistently at 130 lbs.
Lockout pioneered the Wrap and Tie method of installing 130 pound Greenspot on bridles which Trisa uses to pretend to achieve a 260 pound breaking strength. But they claim that it blows at the 130 pound limit they need to keep the new GT aerotow release from locking up more than three out of four times.

And they've obviously read Page 59 of the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden, Reference 4 for Dr. Trisa Tilletti's 2012/06 landmark article on weak links 'cause...
With a "V" bridle angled at 60 degrees or less this will give you a breaking strength of 260 lbs at the tow line.
...they've determined that with a "V" bridle angled at 60 degrees or less this will give you a breaking strength of 260 pounds at the towline - the same figure you get with a "V" bridle angled at zero degrees or less.

I'm guessing they've determined this because they don't want anybody plugging the actual figure of 226 pounds towline into the equation along with his glider's moocow figure and finding that under FAA regulations it's illegal to fly a glider of more than 283 pounds moocow with a standard aerotow weak link and that would put Matt's piece of shit new GT aerotow release which works better than all cable releases that they have experience with totally off limit for a HUGE percentage of the gliders out there.

List of Wills Wing solo gliders from the Nineties on with maximum certified operating weights of 283 pounds or more:

Spectrum
-165

HPAT
- 145
- 158

RamAir
- 146

XC
- 142
- 155

Ultra Sport
- 147
- 166

Eagle
- 164
- 180

Falcon 2
- 195
- 225

U2
- 160

Sport 2
- 155
- 175

T2
- 144
- 154

Falcon 3
- 195

Any of those which have been flown two point with a "standard aerotow weak link" after 2004/08 have been flown in violation of FAA safety regulations.
Zack C - 2011/11/06 14:41:54 UTC

Because knowing me the balloonist I arrange this with will turn out to be an FAA agent and I'll be permanently banned from all forms of aviation, fined for all the money I was saving to buy a rigid, locked up for a month, fired from my job because I now have a criminal record, and unable to find employment the rest of my life because no one wants to hire a thug.
You're a thug, Zack. Here's the proof:

http://vimeo.com/17472550

password - red
2-1306
http://farm8.staticflickr.com/7258/13851486814_77efdf1004_o.png
Image

Maybe when you're rotting in prison you'll be wishing you'd learned how to do a balloon drop so, with a little help from your friends on the outside, you could've escaped from the exercise yard on something you'd concocted from bed sheets, mop handles, and shoelaces.
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

http://www.chgpa.org/forums/viewtopic.php?f=2&t=4788
Highland March20?
Ward Odenwald - 2011/03/22 02:15:06 UTC

To echo what others have already posted - Highland had another great season opener on Sunday! Early morning forecasts indicated light easterly winds during the day coupled with a decent lapse rate/thermal index and by noon the soaring forecasters had nailed it. I flew twice. My first tow took me to ~20 feet above the deck before my weak link snapped, resulting in a fifty yard high-adrenalin flight (in the future, I'll start the new season with new links).
You're flying a Moyes Litespeed RS 4 two point. Moocow is 314 pounds.

A shiny new Ridgely Link puts your max towline tension at 226 pounds which is 0.72 Gs which is .08 Gs south of minimum legal.

Next time you see the crew at Ridgely tell them go fuck yourselves for me. And tell CHGA the same.

P.S. Does Ridgely still have somebody at the head of the flight line making sure you're into your leg loops and main and backup and your carabiner is locked, parachute pins are in, harness and helmet are buckled, bridle is properly routed, Wallaby Release lever is securely velcroed to your downtube, bent pin releases are properly closed, VG and harness cords are properly stowed, and cart trim is properly set? Everything you need to minimize the likelihood of fifty yard high adrenalin flight?

(Useless fuckin' assholes.)
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

Further thoughts on the above.

To the best of my knowledge in the entire history of Ridgely (and I welcome data and/or evidence to the contrary)...

- There have have been ZERO launch crashes as a consequence of:
-- pilot error and/or incompetence;
-- oscillations, lockouts, or stalls resulting as consequences of crosswinds, gusts, lulls, switches, tailings, turbulence, thermals, dust devils;
-- any combination of the above.

- There have been ZERO towing incidents at any altitude that would have had worse outcomes with two G weak links.

- Industry Standard release delays and failures, bridle wraps, and front end weak link failures are so common that a good chunk of the time they don't even merit mention. Many would have been fatal had they occurred in the kill zone instead of at a thousand feet.

- It's always a minor miracle when a Ridgely Link survives a tow on a medium or heavy solo glider in good thermal conditions to release altitude.

- Crashes at or shortly after launch are common enough that I've personally witnessed several (and experienced one myself) and ONE HUNDRED PERCENT of them are directly or indirectly attributable to Ridgely Links.

In other words, if all Ridgely gliders had used two G weak links the record of tow related crashes would be ZERO.

But at the head of the flight line all gliders are checked to insure that they're equipped with a Ridgely Link - pristine on its first flight or safer with a dozen tows worth of fuzz on it. As long as you've installed the one item most and highly likely to crash you they're happy.

True, you will be permitted to have something in the middle of the safety/legal range but:
- that one hundred percent guarantees you you'll end up with the towline when things get tight; and
- the motherfuckers are so negligent in checking the front end weak link that you can end up with the rope just using a Ridgely link anyway.
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=26870
weak links
hangster - 2012/08/22 19:06:11 UTC

So how long should the links be once they are tied? (solo)
Always use an appropriate weak link with a finished length of 1.5 inches or less. Longer weak links are more likely to get tangled on the tow ring upon release.

For tandem always use an appropriate weak link with a finished length of 3.0 inches or less.

Image

Then when it welds itself to the tow ring...

Image

...you wanna spend several pages discussing the kind of knot that should've been used.

http://ozreport.com/forum/viewtopic.php?t=24534
It's a wrap
Zack C - 2012/08/22 19:23:25 UTC

Only as long as they need to be. Longer loops are more likely to get caught on something after releasing. I keep mine under an inch (from the bridle).
But don't make the secondary bridle just as long as it needs to be.

http://www.flickr.com/photos/aerotowrelease/8313526097/
Image

We're not really worried about it getting caught on anything after releasing. Make it two to four feet long 'cause that's what it says in the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden.

P.S. hangster...

Don't gear it for how long it's gonna be once it's tied. Gear it for what it's gonna be after it's tied, installed, and seated under 150 pounds of loading. You'd be AMAZED how much longer it'll get after that process. (And 150 pounds will take all that fuckin' 130 pound Greenspot out of circulation.)
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

P.P.S. hangster...

THIS:

http://www.flickr.com/photos/aerotowrelease/8306296899/
Image

is what you want a string weak link to look like after it's fully seated and loaded. Just long enough so's it won't hang up on the mechanism on a slack line actuation. (I know, it's 130 pound Greenspot. I was a total moron back then.)

And if you're using a two point release mechanism with anything other than this M111S parachute pin as its core there are some other issues you really need to be discussing.

http://www.flickr.com/photos/aerotowrelease/8311348069/
Image
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