Weak links

[Tad Eareckson]

http://www.youtube.com/watch?v=_TDHqsXRtl0
Aerotowing Weaklinks

David Glover - 2008/08/04

http://www.youtube.com/watch?v=_TDHqsXRtl0


What to use, how to make and tie.
---
OK, this is gonna be called "Making Weak Links".

First we start off with Cortland Line Company Greenspot... (This is probably backwards, I don't know how to reverse it, but you can figure it out...) This is what we use.

Then we have this wonderful thing that's made, called "The Weak Link Machine" that I kinda created and, uh... with the help of God...

And then, uh, we spin it up... And we use a drill motor and once off it's all done...

We take a hot knife and we can cut 'em all...

And what's neat with that is they all end up having uniform length and all burned ends.

Now the good thing about the burned ends is it makes it really easy to actually cut (tie).

So that the way we do this is we lay it over like that, then we bring it over, and we just sorta tie a little half knot on one side of this string, and then we turn it over and we do another half knot on the other side of this string.

It's called a Fisherman's.

Then you pull these together, real tight and...

You created a weak link.

So that's it.

That's it! Great Dave! We now know everything we really need to about aerotow weak links!

First we start off with Cortland Line Company 130 pound Greenspot - 'cause this is what we use.

Then we have this wonderful thing that you created - with the help of God.

So at this point we've got the precise strength AND length required for to increase the safety of the aerotowing operation.

The length is Divinely Inspired by The Almighty and...

http://ozreport.com/12.081
Weaklinks - the HGFA rules

Davis Straub - 2008/04/22 14:47:00 UTC

At the 2008 Forbes Flatlands Greenspot for the first time was used as the standard weaklink material (thanks in large part to the efforts of Bobby Bailey). We applaud these efforts to improve the safety of aerotowing by using a better weaklink material.

...we're close enough on the strength. And besides...

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. 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.

What else are we gonna do?

And WOW! With that drill motor you sure can make lots of them fast!

http://ozreport.com/13.238
Adam Parer on his tuck and tumble

Adam Parer - 2009/11/25

Due to the rough conditions weak links were breaking just about every other tow and the two tugs worked hard to eventually get everyone off the ground successfully.

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.

All set then!

http://vimeo.com/17472550

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


http://www.youtube.com/watch?v=bTa6XL16i0U
SCFR Day 2 Highlights
LAGlide - 2011/09/20
dead
021-02800
http://live.staticflickr.com/3848/14609177375_f8c224836d_o.png


http://live.staticflickr.com/5529/14422573378_5385a9a99a_o.png
057-03703

And they work great for scooter towing too!

http://www.youtube.com/watch?v=VYe3YmdIQTM


And a double loop should be just about perfect for tandem.

http://ozreport.com/forum/viewtopic.php?t=865
Tandem pilot and passenger death

Mike Van Kuiken - 2005/10/13 19:47:26 UTC

The weak link broke from the tow plane side. The towline was found underneath the wreck, and attached to the glider by the weaklink. The glider basically fell on the towline.

Say hi to God for me next time you see him - and tell him to keep up the good work!

This is probably backwards...

Yeah, that's a pretty good guess.

I don't know how to reverse it...

I'm thinking if somebody got convicted of negligent homicide and USHGA got sued out of existence we might have a shot.

...but you can figure it out...

I'll keep working on it.

Fuckin' asshole.

[miguel]

A reasoned response is called for.
What do we get?
Invective and call the guy a fuckin ass hole.
That's the ticket!

[Tad Eareckson]

I tried reasoned responses with these motherfuckers for years. I was a little slow in understanding that a reasoned response when dealing with a religious cult leader or one of his zombies isn't a reasoned response.

Calling him a fuckin' asshole and moving on to someone worth talking to is a reasoned response.

You're more than welcome to use whatever approach YOU'VE found to be most effective for getting dangerous junk out of the air and keeping the next Bryan's arm from getting broken in three places - but DO get back to me with your numbers.

My own numbers are, granted, pathetic - but they're a helluva lot better than yours or anyone else's.

If you wanna do something useful in this sport start:

- answering the questions I ask you in these discussions - the way I answer all of yours - so we can reach some resolutions and make some progress;

- understanding its:

-- physics and the reasons we're slamming people in at a rate about twenty times higher than we need to;

-- history so you can understand the motivations of the evil motherfuckers who deliberately and knowingly put thousands of people up on hundreds of thousands of flights on insanely dangerous equipment - like Cortland Line Company 130 pound Greenspot ("This is what we use.");

- speaking out against incompetence and corruption whenever you see it;

- understanding that there's an inverse relationship between integrity and popularity; and

- trading off a lot of the latter for a little of the former.

[miguel]

http://heidiisern.com/wp-content/uploads/2012/07/No_Pity_Party.jpeg

[Tad Eareckson]

Oops.

deltaman - 2012/02/20 07:07:48 UTC

Aerotowing teaching
Do you think there is no useful passive security in AT for teaching other than tandem ? cause asking a student to release at the right moment when he is 100% stressed is not a 100% reliable method.. For example a friend, who is a trike teacher told me this story. He teached an aircraft pilot used to manage radio. When he asked him to make a communication during the take off as he was used to do with his own plane he stopped it without realizing he was so focused on his steering..

The idea of a pitch limiter relative to the tow line is attractive and could be helpful for the first flights in calm air. Yes it is not at all suitable when the glider is at low airspeed, below the tug position and want to push to climb but the lock-out is even more feared for a student and probably with more chance to occur...

I pull text off of the forums and save and work with it in word processing files. For the past few days I've been doing a lot of checking and organizing and just realized I somehow managed to chop off and miss the two paragraphs above. Sorry 'bout that.

Hang gliders - including the ones that don't use weak links - are virtually never a threat to the tug.

Sailplanes - because they're unbelievably clean and fast - are HUGE threats to the tug. They can and do shoot up above it, pull its tail up, and nose it into the ground. It's referred to as a kiting incident - and the lightest of legal weak links can't stop it from happening.

Both Schweizer and Tost sailplane releases will autorelease when the towline angle is such that the glider's overflying a tug (or winch or truck). That capability isn't enough to guarantee that the tug won't be crashed but it sure sounds like a good idea for terminating a bad situation that won't be getting better anytime soon, it doesn't cause any real world problems I've heard or can think of, and I can recall an incident or two in which a hang glider would've survived with something like it.

But otherwise I don't like the idea of autoreleases on hang gliders - in no small part because I'm so sick of this thirty plus year mindset that there's no problem that can't be solved by taking the decision away from the pilot and blowing the glider off tow.

What you describe could save or kill a glider. But even if it would save more than it kills I still don't like the idea because somebody who's trying to do his job might die because he's using a device intended for people who can't do theirs.

Also...

- Even if the pitch limiter blows to mitigate a situation the results could still be fatal or some lesser flavor of bad 'cause the situation's already well out of routine limits when it kicks in.

- Pitch isn't a real big problem on aerotow - for the glider or the tug.

http://www.youtube.com/watch?v=F_n5B3-MIC4

03-0920


The very first time I aerotowed - one point (that's all we had back then) behind a fast Cosmos tug on a glider with a lot of pitch pressure - I couldn't hold it down and was looking pretty much straight down at the trike when I pulled the string (at nine hundred feet).

- ROLL is the problem. And - even if it weren't an astronomically bad idea anyway - good luck designing a roll limiter.

- No students have problems with pitch control - it's easy and intuitive.

- Lotsa people have problems with roll control - it's harder and somewhat counterintuitive 'cause when you want to turn to your left you angle your body to point to the right. On my second lesson - on the dunes - I tried to correct a left turn with left input - and more left input when the glider didn't do what I wanted it to - and slammed straight back into the slope pretty hard. (Wonderful stuff sand is.) And we instructors would see people doing that ALL THE TIME.

- And it takes a while before proper roll input becomes a hardwired, reflexive, muscle memory response.

- So do you really want to be aerotowing someone in whom you have so little confidence in his ability to handle pitch that you feel he might benefit from a pitch limiter?

Aerotowing has some inherent dangers that ground based towing doesn't. Tugs need more airspeed than gliders and the guy at the front end of the string has gotta worry about flying his own plane, can only afford to pay so much attention to the tiny little glider in the convex mirror while he's taking off, and has very little latitude for reducing tension (speed) to help the glider deal with a situation - especially at the most critical stage of the flight.

And when tugs use release levers they virtually always:
- crash a glider that needed to stay on; or
- are too late to do the glider any good.

The record sucks and - as far as I'm concerned - that lever is only there for the safety of the tug and should only be used for that purpose. If you try to use it for anything else you're probably gonna do more harm than good.

The good news for aerotowing is that - because the tow angle is constant and straight ahead - it's very simple, easy, and cheap to design and provide releases for the glider that lets the pilot blow tow with both hands on the basetube.

cause asking a student to release at the right moment when he is 100% stressed is not a 100% reliable method..

Allowing a situation in which there's a POSSIBILITY of a student - or anyone else - becoming one hundred percent stressed is not anything close to a reliable method. The student should never be in a situation in which he's more than thirty percent stressed.

Unlike hill and scooter tow training, we can't take someone off the street and put him in the air for the first time solo behind a tug. So that means before he gets on a cart there's been some other training available to get him to that point. So make life hell for him using that training before he gets on the cart. Make him really learn how to turn a glider even if all you have available is a forty foot hill.

In the US the student is forced to stay upright on the downtubes, told to keep the glider dead level at all times, and everything is geared for standup landings. Do the precise opposite.

Then put him up on a Street Release with a 1.5 G weak link in glassy morning air. If you must have a Pitch and Lockout Limiter use an instructor halfway down the runway with a radio going to the tug pilot. Carefully tow him up to to safe altitude and then stress the crap out of him so the next time he launches he'll barely be able to stay awake dealing with the boredom.

When he asked him to make a communication during the take off as he was used to do with his own plane he stopped it without realizing he was so focused on his steering.

Good! Give that guy a gold star! He's got his priorities straight.

Nobody's ever gotten in trouble being more concerned with a glider than a radio - and there've been some real disasters when people have done the opposite. As a matter of fact there are a lot of laws in the US prohibiting people from using cell phones when they need to be steering cars.

I remember the instructor of my FAA ground school class telling us that in an emergency situation our order of priority is: aviate, navigate, communicate.

When that guy gets comfortable steering the glider on tow he'll start using the radio just fine.

...but the lock-out is even more feared for a student...

Fly him on 130 pound Greenspot for a while.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links

Jim Rooney - 2007/07/22 22:30:28 UTC

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.

Then he'll start understanding that the thing that he really needs to be afraid of is a stall.

In calm air the only way a lockout can happen is if the student makes it happen.

And even in strong thermal air with a student making half an effort to stay level and in position low level / dangerous lockouts are virtually nonexistent.

And with a few ribbons around the runway the instructor can pretty much guarantee that he won't launch the student into something that can overwhelm him.

...and probably with more chance to occur...

Just doing a quick mental review of the towing crashes I know about from over the years I'm not seeing much evidence that the situation you're envisioning is really a problem. The reasons we crash gliders at launch are Davis Links (overwhelmingly), shitrigged equipment jamming and autoreleasing, violent thermals and dust devils, and gliders and tugs failing to stay in position - the former 'cause of crap control authority and/or training, the latter 'cause they don't bother. And there's just about always some combination of the above issues going on when something bad happens.

And those issues and combinations aren't all that difficult to manage.

[Zack C]

For the past few days I've been doing a lot of checking and organizing and just realized I somehow managed to chop off and miss the two paragraphs above. Sorry 'bout that.

Tad,

Speaking of missing posts on this thread...not sure if you missed this one or just declined to comment:
http://www.kitestrings.org/post960.html#p960
I didn't ask for a response or direct it at anyone in particular, but I'm wondering what your take on it is. Hang glider manufacturers may not specify weak link parameters for their wings, but that doesn't appear to be the case with tow planes. But why would their maximum ratings be so low? We don't have a maximum weak link rating on our trike but we've broken 600 lb weak links without issue catching the tow line on something.

Zack

[Tad Eareckson]

...not sure if you missed this one...

No, it immediately burned into my circuitry, I think about it often, I intended to comment, and there's a little check mark next to it in my file reminding me to do so. But I'm easily distracted and sidetracked and there are scores of those little check marks in my files.

OK, let's do this in pounds 'cause, unfortunately, that's the way my brain is wired.

In a recent aerotow weak link discussion someone pointed out that the AirBorne Edge series of trikes have the following on their Hang Glider Aerotow Limitations Placard:

Maximum takeoff weight of hang glider: 551
Maximum weak link strength: 331

The Pegasus XL-R has a maximum weak link specified of 220.

And, yeah, as you say, for the Edge series that's a 0.6 G weak link for the biggest glider they allow you to tow...

Which is:

- 0.2 Gs below the FAA minimum legal weak link for sailplanes

- a bit under half of what what sailplane manufacturers specify for their birds

- 1.4 Gs below / 30 percent of USHGA / FAA maximum allowable

- 1.27 times a "standard solo aerotow weak link" on a one point bridle

- about 1.27 times the towline tension that overloaded the piece o' shit trike release which disintegrated on Chris Bulger and got him killed at Chelan on 1985/07/17

Interestingly, I now realize, about two weeks before Chris was killed the following arrived in everybody's mailbox:

Hang Gliding - 1985/07

USHGA Aerotow Guidelines
from the USHGA Safety and Training Committee

The FAA has granted the USHGA an exemption that allows aerotowing of hang gliders according to these guidelines. Aerotowing is a new and different way of flying hang gliders and must be done according to these guidelines for safety and legality.

II - AEROTOWING EQUIPMENT

1) The tow line connection to the towing vehicle must be arranged so as not to hinder the control system of the towing vehicle.

2) A pilot-operational release must connect the tow line to the towing vehicle. This release must be operational with zero line force up to twice the breaking strength of the tow line.

3) A weak link must be placed between the tow line and the release at both ends of the tow line with the forward link ten percent stronger than the rearward weak link. The weak link must have a breaking strength less than 85% the weight of the hang glider and pilot combination, not to exceed 200 pounds.

4) A release must be placed at the hang glider end of the tow line within easy reach of the pilot. This release shall be operational with zero tow line force up to twice the rated breaking strength of the tow line.

5) A drogue device must be placed midway to 3/4 back from the tow vehicle on the tow line to prevent the tow line from reaching the tow vehicle propeller.

6) The tow line must be at least 150% as strong as the weak link in use.

So the shitheads from the USHGA Safety and Training Committee max out the weak link five percent over the FAA sailplane minimum.

And because there's also a 200 pound maximum - 88 percent of 130 pound Greenspot two point and 77 one and regardless of your flying weight - the only way you can get up to 0.85 is to have a flying weight of 235.

Once your flying weight is over 250 you fall below the 0.80 FAA sailplane minimum.

And a little girl at the bottom end of a Falcon 3 145 maxes out the towline tension at 140.

And the fucking shitheads at the FAA are totally OK with this.

Note also that the towline need only be 300 pounds to cover the max allowable weak link. You could do that with 3/32 inch Dacron leechline. Nowadays we use two thousand pound Spectra (in front of our 130 pound Greenspot) to protect us from dangerous towline failures.

And the release is required to handle twice towline.

A Bailey release would - if it didn't disintegrate first - require require over 48 pounds to blow twice towline.

The victim's manual for the New and Improved Lockout Mountain Flight Park Release precludes the victim from using a weak link which allows the towline tension to exceed 226 - 38 percent of the 1985 standards.

Note that the tug weak link MUST exceed the glider's by ten percent. Now it SHOULD exceed the glider's by a hundred pounds.

Good thing they made those drogue chutes mandatory.

Anybody wanna take a crack at the math that these assholes used to arrive at 85 percent / 200 pounds - whichever comes first?

Be that as it may, it's hard to argue with manufacturer stated operating limitations...

It's hard to argue with any total moron. It's so much easier and more efficient and rewarding just to beat him senseless with a tire iron and get on with the program.

Aerotowing is a new and different way of flying hang gliders and must be done according to these guidelines for safety and legality.

Yeah, right. With max 200 pound weak links - which, for Yours Truly, is 0.6 Gs. And I need 0.4 just to do a normal, smooth air, straight and level climb behind a 914 Dragonfly.

And, by the way guys, I've been really impressed with the concern you've shown for legal guidelines in the better part of three decades since.

Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"The greatest dangers are a rope break or a premature release." - Richard Johnson

Where were the tire irons and people to use them when we really needed them?

[Zack C]

The weak link must have a breaking strength less than 85% the weight of the hang glider and pilot combination, not to exceed 200 pounds.

(USHGA Aerotow Guidelines, 1985)

Wow, I had no idea that was once policy. So what made them increase it so dramatically?

Zack

[Tad Eareckson]

- Inability to get the dolly rolling.

Rob Kells - Wills Wing

The longer rope is then routed through the tow ring and attached to the upper release with a proper weak link.

Wills Wing / Blue Sky / Ryan Voight Productions - 2007/03

Steve Wendt -
But with the towline we use a standard weak link like we would for aerotow... Uh... This... In this particular case it's 130 greenline, 130 pound test.

http://www.hanggliding.org/viewtopic.php?t=14230
pro tow set-up

Ryan Voight - 2009/11/03 00:14:35 UTC

Ummm... If you're holding strong pitch pressure and let it out, I assure you the weaklink will earn it's name, and it will do so at a time of YOUR choosing.

Gregg McNamee - 1996/12

The weak link utilized in this system is one loop of 130-pound test Dacron fishing line - no nicks or frays. When I started towing, years ago, the tow rope was the weak link, and would literally fail the airframe of the glider if the tow pressure was too high. I prefer to learn by example rather than practice, so I accept no substitute when it comes to weak links.

http://vimeo.com/17472550

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


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://groups.yahoo.com/group/skysailingtowing/message/4633
Weaklinks and aerotowing (ONLY)

Steve Kroop - 2005/02/10 04:50:59 UTC

Davis,

Your weak link comments are dead on. I have been reading the weak link discussion in the Oz Report with quiet amusement. Quiet, because weak links seem to be one of those hot button issues that brings out the argumentative nature of HG pilots and also invokes the "not designed here" mentality and I really did not want to get drawn into a debate. Amusement, because I find it odd that there was so much ink devoted to reinventing the wheel.

Collectively I would say that there have been well over a 100,000 tows in the various US flight parks using the same strength weak link with tens of thousands of these tows being in competition. Yes I know some of these have been with strong links but only the best of the best aerotow pilots are doing this.

http://aviacamp.com/

Davis Straub - 2012/02/18

I don't own a hang glider. I exchange temporary use of various hang gliders for Oz Report advertising. I am very generous with the advertising and the companies are very generous to let me use their gliders. In the last two years I have flown in competition or going for world records the Wills Wing T2C 144, Wills Wing T2C 154, Airborne REV 13.5, Moyes Litespeed RS 3.5, Icaro 2000 Z9, Northwing Freedom.

My harness is a Wills Wing Convert. I also have Rotor harness. My vario is a Flytec 6030.

Wills Wing

Wills Wing Quality Partners:

Freeflight Enterprises
Cloudbase Foundation
ROTOR
Learn Live Fly Strong
Charly

http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links

Jim Rooney - 2007/07/22 22:30:28 UTC

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.

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.

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://groups.yahoo.com/group/skysailingtowing/message/612
hang gliding Comments on outlandish release/bridle/weak link

Tracy Tillman - 2001/05/25 01:01:56 UTC

We normally use 130 lb., but we now also have 150 lb. on hand for heavier pilots in draggier gliders. I use 150 lb. for pro-towing, but Lisa still uses 130 lb. for pro-towing. I use 130 lb when using my regular towing bridle.

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://groups.yahoo.com/group/skysailingtowing/message/4592
Weaklinks

Tracy Tillman - 2005/02/08 19:16:10 UTC

If an advanced pilot wishes to use a stronger weak link, the degree of extra strength must be limited. Primarily, the use of a weak link is to save the tug pilot's behind, by preventing structural and/or control failure--and it should also help to prevent structural and/or control failure of the vehicle being towed. Secondarily, a lower-rated weaklink may or may not help to prevent a full lockout--just don't count on it.

A tug pilot and/or aerotow operator has every right to inspect the use and quality of the weaklink used by a hang glider pilot, and has a duty to him/her self and the hang glider pilot to make sure that it is not too strong for its primary purpose. Concurrently, the hang glider pilot has a duty to understand and respect the well-founded concerns of the tow pilot and/or aerotow operator.

http://www.hanggliding.org/viewtopic.php?t=14230
pro tow set-up

Ryan Voight - 2009/11/06 18:14:30 UTC

All the more reason to use a WEAKER weaklink. If you're bending pins rather than breaking the weaklink, I have to think your weaklink is too strong (and now the pin has become the weakest link in the system

http://www.youtube.com/watch?v=eTKIAvqd7GI

Wills Wing - 2011/09/24

Wills Wing Pilots Sweep Santa Cruz Flats 2011

This year's Santa Cruz Flats Race in Arizona, September 18-24, was a great contest with challenging conditions, from weak, blue days to full-blown task-cancelling gust fronts. Jeff O'Brien took first place, with Dustin Martin close behind and Mitch Shipley coming in third. Those three and 5th-place finisher James Stinnett were all flying Wills Wing T2C 144 hang gliders. Joe Bostik and Chris Zimmerman took 9th and 10th place flying T2C 154's, giving Wills Wing six of the top ten places.

http://www.youtube.com/watch?v=r1LbRj-NN9U


http://www.youtube.com/watch?v=bTa6XL16i0U
SCFR Day 2 Highlights
LAGlide - 2011/09/20
dead
021-02800
http://live.staticflickr.com/3848/14609177375_f8c224836d_o.png


http://live.staticflickr.com/5529/14422573378_5385a9a99a_o.png
057-03703

- What dramatic increase?

USHGA changed the number from 85 to 200 on a document that nobody ever reads, adheres to, or enforces but Wills Wing - through its network of dealerships, training programs and materials, and competitions it promotes and supports - establishes and enforces policy. And the policy it has in place drops the reliable maximum for the weak link down from 200 pounds to about 125 - regardless of race, creed, glider manufacturer, or flying weight.

- How much of a chance do you think there will be that, after you talk to Steve Pearson, the Wills Wing glider manuals will be revised to specify recommended and minimum allowable weak link ratings?

[Tad Eareckson]

http://www.paraglidingforum.com/viewtopic.php?t=2859
Towing safety

James Bradley - 2005/06/21 22:15:17 UTC
New York City

Paraglider towing really unnerved me at first. I have done enough of it now to feel confident with it and to get my USHGA towing signoff, but my experience is still limited to 35 tows and it still feels a bit spooky to do it.

Here are some things I think I know about towing. Please chime in with corrections, amplifications, better information, or just your own experiences.

You have your goddam towing signoff - presumably by paying one of USHGA's highly qualified instructors. What do you expect to find out here that you shouldn't have had down solid before you were ever off the ground on the end of a string?

Almost all my towing has been with "payout" winches on vehicles or boats.

You want a winch operator who either has a lot of experience, or who is being assisted by someone with a lot of experience. The operator has a large responsibility, especially in the first part of your flight.

I don't know what the BFD's supposed to be on this. You just tow up and, if anything starts going wrong, the operator...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links

Jim Rooney - 2007/08/01 13:47:23 UTC

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

...can fix it just by giving you the rope.

Right after takeoff is the most dangerous time, of course, because you are close to the ground. If you use way too much brake, and/or if your winch operator uses way too much tension...

You're supposed to call it "pressure".

...you could stall without room to recover.

Why would having too much tension produce a stall?

If you are inattentive or make wrong corrections you could turn away from the tow line and lock out, and if your winch operator does not attentively release tension as you do, you could hit the ground hard.

What's stopping YOU from releasing tension?

At the end of the tow, I prefer to release as soon as I see the car or boat stop, because there is still tension on the line and it is easy to release. Staying on for the last twenty feet of altitude means the line goes slack, and my bridle suddenly requires two hands or a hand and a foot to release.

It also means you get higher - which is the whole point of this expensive dangerous operation.

By then I am normally high, so I have time to deal with it...

Yes. You have time to deal with it.

...but I don't like it when I have any trouble disconnecting...

If you're not under any tension worth mentioning, what's it matter?

...so I prefer to release a few seconds earlier.

That could also mean you that you're gonna land a couple of hours earlier. Your idiot instructor should've trained you to do this right.

With a fixed winch or a loop winch, some people do "step" towing. You get pulled up across the field, then without disconnecting you turn and fly back downwind while the operator freely pays out the line, then you turn back upwind and get towed up again going upwind. One risk is if something jams the line while you're flying downwind, you could find yourself in a strong downplane without a lot of room above the ground.

Which is why it's a really bad idea to turn downwind without a lot of room above the ground in the first place.

Seems like it would be prudent to fly downwind with one hand on the tow release...

When would it NOT be prudent to be flying with a release you can blow at will without delay or control compromise?

...but if it's thermic you might not want to put the brakes in one hand to do that.

I might not want to go up with anything which necessitates a control compromise to effect a release. Sounds like you don't either. How tough would it be to rig a bite actuated release for these things? (You assholes could do it in your sleep but you get away with this bullshit at a high enough frequency that you don't bother.)

Some very experienced people refuse to do step towing. I have not done it and I think if I can't find a thermal and get away from a one pass tow, I'm ok with not flying that day, but I'd be interested to hear your experiences.

Then why bother going out in the first place?

You will have a "weak link" between your bridal and the towline...

Of course we will.

Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"The greatest dangers are a rope break or a premature release." - Richard Johnson

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Jim Rooney - 2011/08/26 02:44:10 UTC

The "purpose" of a weaklink is to increase the safety of the towing operation. PERIOD.

Why would any responsible pilot not want to increase the safety of the towing operation when the means of doing so is so simple?

...a loop of line that is designed to fail at a certain amount of load.

Yes - a CERTAIN amount of load.

Get some advice from an expert about weaklinks...

- Oh yes. Definitely get some ADVICE from an EXPERT about weak links.

- I thought we already knew everything we needed to about weak links. They're designed to fail at a certain amount of load.

- Didn't you just pay a fucking expert about weak links for his advice?

- What was it?

- What were you using for your 35 tows?

- Why?

- Guess he got the design strength just right 'cause you've had 35 tows and haven't been killed yet.

- How come in sailplaning there are no experts on weak links? How come it's just in hang and para gliding that we have hundreds of experts on weak links - and thousands of opinions regarding their purpose?

...and if you can, get a couple of meters of weak link line...

Yes. Go to your friendly neighborhood fishing store and get a spool of the stuff they designed for towing YOUR glider up to a CERTAIN amount of load.

...make your own, and keep extras with you.

So you can keep replacing them after they save you from fatal lockouts six times in a row.

The one that is on the towline may have dragged a lot on the ground.

Then it would be under the precise value carefully determined by an expert to break in an emergency but not too easily.

You want the weaklink to break in an emergency, but you don't want it to break too easily.

Told ya so.

If you get a strong wind gust just as you take off, and say the operator has the tension a little too high, your wing will rock farther behind you than usual and put more pressure...

There ya go! You're starting to get the lingo down!

...on the weaklink.

I wouldn't worry. A weak link selected by an expert will only fail to defuse an emergency - never to create one.

If the link brakes while you are still in this attitude and very low, you could get a pitch rotation and surge that you can't catch before you hit the ground.

Dude!

Jim Rooney - 2011/08/26 02:44:10 UTC

The "purpose" of a weaklink is to increase the safety of the towing operation. PERIOD.

NO WAY! Remember... It always INCREASES the safety of the towing operation. PERIOD. It is - by definition - PHYSICALLY IMPOSSIBLE for it to crash you.

Usually an early release or weaklink failure doesn't mean an accident...

Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"The greatest dangers are a rope break or a premature release." - Richard Johnson

Usually skipping a hook-in check and running off a ramp doesn't cause an accident. I really wish it did though 'cause that's the only way we'll ever be able to get people to start doing hook-in checks.

...but with other contributing circumstances a frayed weak link that is now too weak could cause an accident, so it is worth taking responsibility for your weak link the way you do for the rest of your gear.

- Yeah. If you get a weak link designed to fail at a certain amount of load on the advice of an expert the only way it could possibly cause an accident is if you allow it to become frayed.

- You're not taking responsibility for your weak link 'cause you have no fucking idea what either its strength or purpose is. What was the name of the asshole who signed you off?

Seems like it would be prudent to fly downwind with one hand on the tow release, but if it's thermic you might not want to put the brakes in one hand to do that.

- You're not taking responsibility for the rest of your gear either. You're using some crap that's dangerous and that you're afraid of 'cause that's what some asshole set you up with.

- And if you get mangled as consequence of either your shit weak link or your shit release system I one hundred percent guarantee you that none of the motherfuckers who've taught or advised you or are regulating the conduct of these operations will be taking responsibility for shit.