Releases

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=22660
What can be learned from this "scooter" towing accident?

Jim Rooney - 2011/01/26 17:41:28 UTC

Mostly this has been pilots using single barrel releases with the weak link on the barrel side and the bridal directly attached to the other side. I'd tell them to at the very minimum, put the weak link on the harness side, not the barrel. This is AT towing... the "conventional wisdom" thinking is that you can generally overload the weaklink if necessary during a lockout if the bridal snags after releasing the barrel.

Marc Fink - 2011/01/27 06:50:13 UTC

I've used weaklinks on tow-line end when towing paragliders with a split string-style release--it's fairly common to have a weaklink "hang up" or stick if using a thin (i.e. cortland greenspot) loaded over a thicker/softer string line.

Larry West - 2011/01/26 16:29:58 UTC

We can have a discussion about releases, but every release will fail someday, so let's agree on a process that expects failure and deals with it.

They fail ONLY because of and at rates in direct proportion to the MONUMENTAL stupidity of the people "designing", configuring, and using them.

You'd think that failure to hook in incidents would eventually work to improve the gene pool a bit but it's always the wrong people who survive them.

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=22660
What can be learned from this "scooter" towing accident?

Tom Lyon (Jackie B) - 2011/01/28 16:51:56 UTC

I had this happen once several years ago with my instructor. It was very startling, but the rope almost immediately worked its way loose on its own. The tow pilot, feeling the problem, instantly released from his end as well. We ended up retrieving the rope from a corn field.

I didn't think too much more of it at the time and the instructor didn't seem too concerned, either. However, I have wondered since if it was a potentially much more serious situation than I thought at the time. Was it? Would we have been able to control the hang glider with the towing force transferred up to the keel? Was there a backup way to release that if we needed to? I don't recall.

When I return to hang gliding this summer, I'll be taking lessons at one of the best schools in the country (DFSC/Cloud 9 in Michigan), so I'm sure they are well aware of what needs to be done to minimize the possibility of a tow rope getting caught upon release.

Jackie,

I had this happen once several years ago with my instructor. It was very startling, but the rope almost immediately worked its way loose on its own.

1. Lucky both of you.

2. And almost certainly there was nothing in the way of a weak link on your secondary bridle - 'cause if there had been by the time you'd been startled the problem would almost certainly have been over.

3. So why was there nothing in the way of a weak link on your secondary bridle?

The tow pilot, feeling the problem, instantly released from his end as well.

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!

1. Lucky all three of you that your driver didn't get a wrap too.

2. Another alternate scenario...

Shane was a smart pilot and the tow operator had a response loaded (cut the line), but no one had talked about snagging the line, so the one thing no one prepared for was the one thing that happened.

...in which other people would have ended up retrieving the rope, your bodies, and the wreckage of the glider from a corn field.

I didn't think too much more of it at the time and the instructor didn't seem too concerned, either.

Yeah, brain dead instructors never get too concerned about potentially lethal equipment deficiencies and malfunctions. That's why people like Dan Cudney, Joel Lewis, Chris Bulger, Mike Dorobiala, Brad Anderson, Eric Aasletten, Harold Austin, Frank Sauber, Richard Graham, Rob Richardson, Debbie Young, Mike Haas, Robin Strid, Arlan Birkett, Jeremiah Thompson, James Simpson, Steve Elliot, Roy Messing, Lemmy Lopez, and Shane Smith end up dead.

However, I have wondered since if it was a potentially much more serious situation than I thought at the time. Was it?

Peter Birren - 2007/08/22

If I recall correctly, there were a couple of incidents at Whitewater a few years ago that were just what you described. I'm thinking of two women pilots who were hospitalized.

Nah.

Would we have been able to control the hang glider with the towing force transferred up to the keel?

Peter Roth - 1983/11

At this time the rope was still connected to the keel. Just as the pilot tried to release manually, full power to the keel jerked the glider into a vertical dive. The pilot was thrown into the sail. At this instant, the bolt holding the crosstubes together sheared off and the glider folded up, spiraling in a vertical dive. The pilot could not throw his parachute.

http://ozreport.com/forum/viewtopic.php?t=11591
Where to put the weaklink - the HGFA rules

Rohan Holtkamp - 2008/04/21

I know of just one pilot to survive this type of hook-up, took him some twelve months to walk again though.

Sure.

Was there a backup way to release that if we needed to?

Rohan Holtkamp - 2008/04/21

Once again history has shown us that this thread-through system can hook up and the hang glider remains being towed by the keel only, with the bridle well out of reach of even a hook knife.

But in your scenario you wouldn't have been towing from the keel - you'd have been towing from your shoulders. But with no weak link...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3107
I have a tandem rating!!!

Lauren Tjaden - 2008/03/23 22:20:15 UTC

When Jim got me locked out to the right, I couldn't keep the pitch of the glider with one hand for more than a second (the pressure was a zillion pounds, more or less), but the F'ing release slid around when I tried to hit it. The barrel release wouldn't work because we had too much pressure on it.

...and twice as much "PRESSURE" as Lauren and Dustin had on their piece o' shit Bailey release, you could still have been killed - but probably not as fast.

When I return to hang gliding this summer, I'll be taking lessons at one of the best schools in the country (DFSC/Cloud 9 in Michigan), so I'm sure they are well aware of what needs to be done to minimize the possibility of a tow rope getting caught upon release.

No, Tracy's just another asshole clone from the Matt, Bo, Bill, Davis, Jim, Marc mold.

A few questions for you...

Gerry Grossnegger - 2011/01/28 02:57:20 UTC

In this photo Davis is using a short tow bridle through the tow rope with a weak link on the left and a barrel release on the right. It would be Ok to put the / another weak link on the right, between the bridle and release.

1. Why is his "short" bridle twelve times longer than it needs to be? If it were four to ten inches would the possibility of it wrapping even exist?

2. Why is there no weak link on the right end of the bridle?

Davis Straub - 2011/01/28 07:28:51 UTC

Yes, but the reason it is done the other way is that the weak link serves as the second release.

3. How come Davis - who never has been and never will be smart enough to tell the difference between a release and a weak link - doesn't use a second release to serve as the second release instead of a weak link to serve as the second release?

Jim Rooney - 2011/01/28 11:04:40 UTC

HG AT, 3 point setup, tandem.

If you release while under load, the chances of the rope grabbing the tow ring are substantial.
When you're doing 20-30 tows a day, some things get obvious. This is one of those things.
Pull in a touch before you hit the release and the problem virtually disappears.

4. What if you don't have the luxury of pulling in a touch before you release 'cause you're already pulled in to your knees and/or you needed to release two seconds ago to live?

Matt Taber - 2009/05/11 21:48:48 UTC

In all of my experience as a pilot -- tandem pilot and tug pilot I have not seen, heard about or experienced this. Is it really an issue or a perceived issue?

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

Jim Rooney - 2009/11/02 18:58:13 UTC

Oh it happens.
I have, all the guys I work with have.
(Our average is 1 in 1,000 tows)

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.

6. If it's so fucking easy to make the problem virtually disappear how come in emergency simulation drills they have a failure rate of over fifty percent?

This is far more likely with the long top bridal as it whips around a bit as it goes through the ring.
I would not call it inconceivable for a short bridal to do the same. It would seem far less likely, but not impossible.

7. Since the wraps always occur within the last few inches of the bridle, why should a "short" bridAl be any less likely to wrap than a TWO point (long) bridle?

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=22660
What can be learned from this "scooter" towing accident?

Tom Lyon - 2011/01/28 22:55:48 UTC

If I shouldn't derail this thread (Davis, Scare), please let me know and I'll start a new one or ask Jim via PM. Since this is related to towing safety, I'm hoping it's appropriate.

OK, now I remember. The main release was at the top and activated by the bicycle handle on the control bar. I think it used a sailboat spinnaker release. The other two attachments were on the harness.

We weren't ready to release. The conditions were smooth and we were towing normally when the weak link broke on the harness. The bridle snagged for about one to two seconds as it worked its way through the carabiner or whatever was at the end of the towline. It was at a reputable flight park, so I'm sure they were using a good set up.

One takeaway for me was the experience of how it all happened so fast. The emergency systems definitely need to be set up to require as little human input as necessary. I know that's just common sense, but I've found myself saying "In this situation, I would..." when really, I'm almost certainly not accurately imagining the speed of the event and the stress of the situation.

If I shouldn't derail this thread (Davis, Scare), please let me know and I'll start a new one or ask Jim via PM. Since this is related to towing safety, I'm hoping it's appropriate.

http://groups.yahoo.com/group/USHPA/message/444
Davis, the Censure Bully, Straub, Strikes Again

Warren Narron - 2009/02/16 16:18:49 UTC

Now Davis suppresses tow release information from Tad Eareckson on the Oz Report forum.

I call foul on Davis for being such a controlling jerk 'moderator' bully that just can't stand any free and open thought.

For whatever reason, Davis has a mental limitation that can't tolerate free thought. His actions are an impediment to the ongoing innovation and safety considerations of hang gliding.

This is a serious offense, in my opinion.

Davis effectively killed that thread by again being the bully.

The only reason that thread's still going is because nothing substantive is being said or done by way of learning "from this "scooter" towing accident" which - by the way - was NOT, by any stretch of the imagination, an ACCIDENT.

The main release was at the top and activated by the bicycle handle on the control bar. I think it used a sailboat spinnaker release.

See, here's part of the problem. BICYCLE handle... SAILBOAT SPINNAKER release... You don't HAVE brakes or spinnakers on gliders. Those components are designed for different purposes on different vehicles. Both of those items have inappropriate elements which have killed people before and will do so again.

http://www.hanggliding.org/viewtopic.php?t=11497
Aerotow release options?

Axel Banchero - 2009/06/20 04:57:01 UTC

I just kept hitting the brake lever for a few seconds in WTF mode, and the instructor used the barrel release.

Ralph Sickinger - 2000/08/26 22:18:20 UTC

I pulled on the release (hard), but nothing happened! After the second failed attempt to release, I thought about releasing from the secondary, but before I could move my hand the tug stalled and started to fall...

http://ozreport.com/9.009
2005 Worlds

Davis Straub - 2005/01/11

Rohan Holtkamp did an analysis of the accident, in particular the bridle and weaklink, which never broke. The weaklink was caught on the release mechanism, a standard spinnaker release found on bridle systems used at Lookout Mountain, Moyes, Wallaby Ranch, and Quest Air. The release clamp has an arm that is thicker at the release point and this held onto the weaklink which consisted of multiple loops of thick line.

The conditions were smooth and we were towing normally when the weak link broke on the harness.

Jesus H. Christ. You ACTUALLY WERE towing from the keel - WAY the hell in front of the hang point. Next time somebody gives you a choice between doing that and playing a round of Russian roulette you might not want to dismiss the idea of the revolver too readily.

It was at a reputable flight park, so I'm sure they were using a good set up.

In-fucking-credible. What's a flight park gotta do to become a DISreputable flight park? Needlessly killing people doesn't seem to work so I guess a potentially lethal malfunction like this is never gonna make any difference.

Let's make the flying weight 450 pounds and call the normal tow tension 175 pounds - which is probably pretty generous.

Let's put double loops of 130 pound Greenspot - 200 pounds - on the top end of the primary bridle and between one end of the secondary bridle and a tow loop.

So during normal climb your primary weak link should be feeling a hundred pounds and your secondary fifty. Your secondary weak link blew at a quarter of what it should have and this is a REPUTABLE flight park?

When I return to hang gliding this summer, I'll be taking lessons at one of the best schools in the country (DFSC/Cloud 9 in Michigan)...

Yeah, with the bar that low it probably is.

Jim Rooney - 2011/01/29 09:15:02 UTC

Too right Jackie.

That "little detail" is so often overlooked or at best under-appreciated.
The shit can hit the fan exceptionally fast. And not... "wow, that was kinda quick"... but "holy crap! What just happened?".

Unfortunately, it's not until you've been through it that you get a real sense for it. Lord knows I didn't.
Then, all those things that make sense sitting here on the couch kinda go right out the window. Those plans of "Why, I would just.. bla bla bla" instantly look as silly as they are.

When my top bridals have tied on for example, I think I was able to hit the secondary once before the chest weaklink broke... and you bet your ass I always flew with a chest weaklink in addition to the top release weaklink. Some consider having the second weaklink overkill... and it's obvious that they've never had a tie-on... things get real obvious real fast. That's one of them.

I'm with you... the less human interaction, the better. I call it "stacking the deck in your favour".

The United States Hang Gliding and Paragliding Association, Inc.
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
10. Hang Gliding Aerotow Ratings
-B. Aero Vehicle Requirements

05. A weak link must be placed at both ends of the TOW LINE.

Hang Gliding - 1997/02

Tad Eareckson

To further address the danger of a primary release failure (bridle wrap), a secondary weak link, of strength somewhere between significantly stronger than and double that of the primary, should be installed at the other end of the primary bridle. Note that a double strength link will fail at a somewhat higher tow tension than is allowed by the primary, as the primary bridle has ceased being a bridle and is now an extension of the towline (as explained in Dennis Pagen's and Bill Bryden's November article), but you'll still be in a reasonable ballpark. Also note that this secondary link may make the effects of the snagging of a trailed primary bridle (the potential for which is illustrated on the December issue's cover) a lot easier to live with.

First known reference to having weak links on both ends of the bridle - thereby configuring in compliance with the SOPs.

Towing Aloft - 1998/01

Weak link on one end ONLY of primary bridle. No references to secondaries.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=939
Weak link breaks?

Daniel Broxterman - 2005/08/26 14:28:42 UTC

While we're on this topic...at Wallaby in April the launch crew put a second weak link in my system between the bridle and the Bailey. I fly with a two point, Wallaby-style release, with a single Bailey secondary. As I recall, here's the scenario they had in mind:

Pilot releases with primary, bridle catches on the tow line or release mechanism. If pilot becomes extremely out of position, the additional weak link would probably break prior to pilot finding and pulling Bailey.

Does anyone else use two weak links, one on each release point?

Second known reference to having weak links on both ends of the bridle - eight and a half years after first.

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

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

Also, the hang glider pilot should only use one weaklink, at the upper attach point in a 3 point bridle system, to prevent tucking should the bridle release at the low end and snag the ring. We have had excellent results using that system.

Regards,

Tracy Tillman
Draachen Fliegen Soaring Club
Cloud 9 Field
11088 Coon Lake Rd. W.
Webberville, MI 48892

"One of the best schools in the country (DFSC/Cloud 9 in Michigan)," UNDOUBTEDLY "well aware of what needs to be done to minimize the possibility of a tow rope getting caught upon release", warns of the extreme danger of any semblance of complying with the then decade-old requirement 'cause Tracy's too stupid to understand that a weak link on the end of a secondary bridle:
- is only feeling half of what the one on the primary is; and
- can be made out of heavier material.

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

During a turn when tow forces were too strong, my weak link broke. But bridle was still attached to the tug because the bridle was coiled and had wrapped itself around the carabiner. However I had left the weak link intended for pro-tow on the harness and it broke. This happened in no more than 2 seconds.
Since then I when I set-up I make sure the bridle has no twists and still keep the pro-tow weak link.
Anyone who wants recommendations for their towing or training, you have a great pool of knowledge in the tow parks especially from the ones that do it regularly and have the experience in the tug and behind the tug.

Carlos, flying at Highland Aerosports, the team of highly experienced and knowledgeable professionals that made Jim Rooney the MAN he is today, has a secondary weak link to mitigate the danger created by his primary 130 pound Greenspot only as a matter of luck - meaning they're still doing shit in the way of training pilots and ensuring safety and compliance.

Unfortunately, it's not until you've been through it that you get a real sense for it. Lord knows I didn't.

When my top bridals have tied on for example, I think I was able to hit the secondary once before the chest weaklink broke... and you bet your ass I always flew with a chest weaklink in addition to the top release weaklink. Some consider having the second weaklink overkill... and it's obvious that they've never had a tie-on... things get real obvious real fast. That's one of them.

Ya know, Jim, I didn't actually NEED to go through that thirteen years ago to understand that it COULD happen, the potential consequences of it happening, and how to configure to protect against it happening. And I was using a secondary weak link at Ridgely on Day One of its operation - long before anyone else was and WAY long before you first blighted the dump.

And I knew the difference between "bridle" and "bridal" back then too.

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=22660
What can be learned from this "scooter" towing accident?

Jeff Johnson - 2011/01/29 17:05:47 UTC

Was out there yesterday seen the setup spoke to an eyewitness.

Yes, Weak link (205? leach line loop)at the end of the tow line instead of a carabiner.

Pilot was using pro-tow with barrel release and bridle. He did at least one tow with the proper set up (Carabiner) other pilots were using a three ring release around the weak link without the carabiner.

The carabiner did not get put back on and his bridle was routed through the weak link on his last tow which jammed.

What happened after that ??

Yes, Weak link (205? leach line loop)at the end of the tow line instead of a carabiner.

Pilot was using pro-tow with barrel release and bridle. He did at least one tow with the proper set up (Carabiner) other pilots were using a three ring release around the weak link without the carabiner.

01. Bill Booth invented the three-ring release as a cutaway for skydiving in the Seventies. The whole principle of the mechanism - and the three-string spinoff developed in hang gliding to reduce the mass of something that might hit you in the face - is that you go from smaller to larger - NEVER the other way around.

02. Nobody was using three-rings 'cause there's no way they would've worked engaged directly to a leechline loop. They were using three-STRINGS.

03. The people that were using three-strings without the carabiner were asking for it. They were undoubtedly going from larger to smaller diameter string and risking a lock as well as burning the weak link (and the third loop unnecessarily) and reducing its rating. Two ways to kill yourself towing - come off when you need to be on and lock on when you need to be off. Might as well hit 'em both.

04. What fucking moron(s) took the carabiner off and why?

05. Shane's bridle was undoubtedly hollow braid with eye splices in the ends.

06. If you do it right you overlap the ends of the line in the middle so that the thickness of the bridle tapers.

07. Nobody does it right so there would've been bulges near both ends.

08. Either one of said bulges would've virtually guaranteed a lock.

09. Everybody also makes these bridles a dozen times longer than they should be and there isn't a doubt in my mind that that was also the case here.

10. Even if Shane had had benefit of a tow ring he was still vulnerable to a wrap and this day could've ended just the same.

11. For well under five bucks of material and as many minutes of time you can make an infinitely better barrel release than the bent pin shit that everybody sells and uses.

12. At the time of the attempt this was a routine - non emergency - release situation.

13. After it started becoming an emergency situation there was plenty of time for the operator to cut his end of the line.

14. There was WAY more opportunity for the Shane to blow the under five dollar release that he didn't bother to have on the other end of his bridle.

15. This wouldn't have happened if these idiots had been using bridle and release integrated weak links.

16. This wouldn't have happened if these idiots had been using Tost weak links.

17. This wouldn't have happened if these idiots had been using NO weak links.

18. Robin wouldn't have been killed if he had been using NO weak link.

19. Robin Strid - 2005/01/09
- shit release
- no bridle
- shit weak link
- no tow ring
- no secondary release

20. Shane Smith - 2011/01/15
- shit release
- double shit bridle
- shit weak link
- no tow ring
- no secondary release

21. http://ozreport.com/forum/viewtopic.php?t=22660

What can be learned from this "scooter" towing accident?

22. Yeah. What CAN we learn from THIS unbelievably stupid towing CRASH?

23. I'm sorry but this is pure unadulterated Darwin material.

Jim Rooney - 2011/01/29 19:01:47 UTC

Thanks for the update Jeff.
Good to have a clear picture of things.

I'm going to save the rant... it'll do no good.
We've been towing for years. We worked this shit out a long time ago.
You either follow the well worn path or you take your own.

We've been towing for years. We worked this shit out a long time ago.

WE worked this shit out a long time ago?

You first hooked into a hang glider in 2002. You didn't help develop the three-ring because it and you are about the same age. I hooked up behind a Cosmos trike with one 1986. What the fuck has been worked out in towing technology - that you haven't gone out of your way to suppress anyway - in the past couple of decades?

You either follow the well worn path or you take your own.

Yeah Jim, let's get the lockup rate down from a hundred percent - like the assholes at Phoenix Regional had it...

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.

...to something over fifty - like you assholes at Ridgely have it. But use Dragonflies so when it happens you usually have half a mile of air underneath you to deal with it.

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. At that point I realized I had the rope, so I drop it in the parking lot.

Fuck people over up high so when you dump the rope on them it doesn't immediately snag on the ground and kill them.

Davis Straub - 2011/01/29 21:27:11 UTC

Pro-tow on a scooter tow? Boy that makes no sense either.

Yeah Davis, no sense whatsoever.

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



And Robin's configuration made no fucking sense whatsoever either. But I didn't see you doing anything to get it off the flight line before he got killed - or at Ridgely at the ECCs when it continued to go up.

http://www.hanggliding.org/viewtopic.php?t=20529
Shane Smith - RIP

Davis Straub - 2011/01/18 12:47:46 UTC

I would look at the weaklink loop and the need for two releases (unlike in aerotow).

Yeah, there's no conceivable set of circumstances in which...
- it might be advantageous to have two targets for two hands on two shoulders in a lockout
- that stupid four foot one point bridle of yours could wrap at the tow ring

http://ozreport.com/9.032
The Worlds - weaklinks

Rohan Holtkamp - 2005/02/07

A full lockout can be propagated with less than 40 kg of tension. Read "Taming the beast" on our website and/or come have a look at the video if you doubt this in any way.

- That stupid 60 kg weak link on your left shoulder wouldn't blow even if it did.

Oh well, even if you never get killed as a consequence there's always the possibility that someone who looks up to and respects you will.

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=22660
What can be learned from this "scooter" towing accident?

Gerry Grossnegger - 2011/01/30 04:40:49 UTC

I've done it (single-point bridle under the bar) from a dolly with a big stationary winch, but I wouldn't recommend it. You've really got to lean on the bar for the first part, and if the bridle were to go off-center it would be... bad.

Why did I do it? Honest, I did not say "watch this, hold my beer". Probably to see if it could be done, and find out if it should be done. Yes, and no.

Yeah Gerry, it was done by everyone until 1982 when the Lake Bridle - the predecessor of the Koch two stage release - came out. After that nobody really had to. (Those who are unable to learn from history...)

David Williamson - 2011/01/26 00:03:23 UTC

If you can't drop the line you MUST throw your reserve.

This is like advice for what to do after you launch unhooked. There is absolutely no good reason for being in a situation like that and your prospects aren't great no matter what you do.

Steve Seibel - 2011/01/30 05:29:18 UTC

Some people might think it's a good idea to have multiple weak links, including one in the end of the towline.

For every every configuration there's a best way to do things - and it has nothing to do with what people "think" and everything to do with physics and engineering.

Steve Seibel - 2011/01/30 05:39:51 UTC

Hmm, I seem to recall being instructed to put the weak link on the barrel side. Can't remember why-- it seemed odd to me but there was some specific reason.

Yeah, the specific reason was that the person so instructing you was an idiot.
- What was the weak link? A loop of 130? Why?
- Did the barrel have a curved pin? Why?
- Why weren't there TWO barrel sides?
- How long was the secondary bridle? Why?

As I understand it a weak link often does not break at low enough force to prevent entering a lockout so it sure won't save your butt down low...

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

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

Weak links are there to protect the equipment not the glider pilot. Anyone who believes otherwise is setting them selves up for disaster.

The weak link is not there to save your butt at ANY altitude.

Steve Seibel - 2011/01/30 05:58:38 UTC

Well lots of food for thought here. No doubt mostly obvious to those with lots and lots of tow experience.

NONE of this has ANYTHING to do with EXPERIENCE. ALL of it has EVERYTHING to do with physics and is obvious from within that context. And most of the people with the most experience are the ones least "equipped" to understand physics.

I often aerotow with a three-point system...

No, you don't. You tow TWO point - pilot and glider. Nobody tows three point anymore.

...but have considered using the barrel as the primary and the spinnaker as the secondary. So that one of the bridles stays up on the keel, out of my way, and I don't have to deal with tucking it away.

"Tucking" being the operative word here.

Now seems clearly not a good idea...

For someone as intelligent as you are it's absolutely astounding that that would EVER have seemed like anything but an EXTREMELY BAD idea.

...even for one second, as long as it takes to reach for the spinnaker release handle...

Why is your spinnaker release handle someplace where you have to - and may very well not be able to - REACH FOR it?

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 second time it happen I saw the tug line 45 degrees off to the left and was not able to align the glider again I tried to release but my body was off centered and could not reach the release.

What's the point in discussing how you're not gonna release from the bottom to keep from being killed in a tuck while leaving yourself WIDE OPEN to being killed in a lockout?

What makes you think you're gonna have the luxury of being able to squander that one second even if you don't wind up upside down while you're REACHING FOR the spinnaker release handle?

Jim Rooney - 2011/01/30 09:09:45 UTC

Yeah, people have lots of voodoo (BS) reasons they like to do things incorrectly.

So who were the total assholes who signed them off, Jim?

The usual "reason" for putting the weaklink on the barrel side is that it fits the barrel "better". I don't like anything directly attached to my harness. I couldn't care less what this guy thinks is a "good reason" to put it on the other side. He wants a weaklink on that side... great... but put one on the other side as well.

I love weekend warrior "experts".

Ya know, Jim... It was largely through several decades worth of the efforts of weekend warrior experts that hang gliding and towing got handed to useless assholes like you on silver platters when you finally got around to it.

Weaklinks don't save your butt... you do. They just help you.

Bullshit.

If you want to overload a weaklink on AT... it only takes a fraction of a second. So yeah... you can do it down low.

Yeah Jim. When you're fighting the stall and roll just push out and roll a little harder... it only takes a fraction of a second. So yeah... you can do it down low. You can also launch unhooked and lose your grip on the basetube and be doing just fine for the next second or two. But after either procedure the results can be EXACTLY the same. So what's your point?

I don't recommend it, but it's a damn sight easier than you're thinking.

Ya know what I recommend? While continuing to fight the stall and roll just twist your grip and release.

A bit of an eye opening experience that I don't suggest you try... this is something taught under very controlled conditions... is "lockout training". Essentially, you slowly get out of position behind a tug. Do it smoothly enough and you'll be surprised how long that little weaklink holds out and how exceptionally fast lockout accelerates from "a little bad" to "holy shit!"

Here's the other side though... don't do it smoothly and you'll see how fast that little weaklink gives up.

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.

1. But then your bridle wraps over half the time.
2. So what you're saying is, accelerate a low level lockout to try to blow the weak link. So what happens next?

Many have seen this first hand as they fly through the propwash behind a tug without pulling in... *pop*.

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.

Yep - *pop*. No more weak link, no more tow, no more problems.

Marc Fink - 2011/01/30 14:24:47 UTC

I'm still not understanding the mechanics of this accident--and all this aerotow protow conjecture also confuses the situation for me.

There's still not enough information regarding the tow set-up arrangement and attachment points--but routing the bridle through the weaklink on tow line end would seem to me to be clearly asking for trouble--though I've not independently tested this.

Oh Marc, PLEASE independently test this. Everybody wants to make ABSOLUTELY SURE.

[llwest@comcast.net]

Glad to be reading some more rational thoughts here.

I'm a pessimist (I say realist, some say pessimist) and still try to take the attitude that everything will fail and have a response loaded to each failure. You are very correct that a side-wire failure is going to be catastrophic and probably fatal so we put a lot of effort in to testing and replacement of that critical component, but I do still assume that component can fail and I will have to tuck myself in to a ball with my head down and try to survive that if I'm low.

What I'm trying to say is that I look at every point of failure in the process (and I think engineering the process is more valuable than engineering hardware) and try to have a response planned for it, even it it is still going to hurt or kill me (now that I'm thinking about it, the only cascade of events I built in my head that would end with me saying "nothing I can do but die" is very short). I have some hope in almost every imagined situation) but still don't think there is any release that doesn't have a failure mode.

The release Shane was using (barrel/pin) is one I wouldn't trust AT ALL (I send people links to your image library to back that up), but turning away from the line while still attached is NEVER a response I train.

Looking forward to reading things over here after getting frustrated reading over on Oz and HG.org. Thanks for putting this up.

I've been trying to conceive of a inline "line cutter" squib that would be cheap and easy to fire off from either end under certain conditions, but haven't found the tech that I would trust yet. I want to be able to disconnect from the line reliably if the release jams or the operator passes out, but then would have to develop a plan for dealing with THAT failing.

Logic is a bitch.

Keep up the conversation.
Thanks Tad

[Tad Eareckson]

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

Bill Reynolds - 2009/11/02 18:44:46 UTC
Florida

Hey forum,

Is the two barrel release set-up overkill? I need to buy a tow set-up, so I ask myself this question. Why not have just one barrel release off my right shoulder, with the tow bridel permanently tied to the left should loop?

THX

Craig Hassan - 2009/11/02 18:51:59 UTC
Ohio

If the bridal gets caugth up in the tow line you could have issues with 1 barrel. I've only seen this happen on scooter tows with a bowling loop at the end of the tow line. I've never had it happen with AT and a metal biner/ring at the end of the tow line.

Jim Rooney - 2009/11/02 18:54:34 UTC

If you use a single barrel setup, have the weaklink on the other side.

This way you don't have a piece of rope tied directly to you.
Every now and then, ropes like to grab things
Extremely not likely, but... well, why not just avoid the situation all together?

Jim Rooney - 2009/11/02 18:58:13 UTC

Oh it happens.
I have, all the guys I work with have.
(Our average is 1 in 1,000 tows)

As I said, the odds are with you, but still... slapping the weaklink on the other side is such an easy solution.

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.

DaveB - 2009/11/03 01:15:45 UTC
Fort Collins

While we were not using a "Pro Tow " setup, on my very first AT lesson the bridle from a Lookout Mountain style release promptly wrapped itself around the towline carabiner prompting an even quicker secondary shoulder release by my instructor.

In fact, in three weekends of crack of dawn lessons and then ground crewing for the day for the rest of the pilots, the incidence of a bridle tangling seemed almost one in twenty-five to thirty.

http://ozreport.com/forum/viewtopic.php?t=22660
What can be learned from this "scooter" towing accident?

Mike Lake - 2011/01/31 00:19:06 UTC

If you release while under load, the chances of the rope grabbing the tow ring are substantial.

Jesus.
I find this a disturbing statement.
In the UK this would just not be acceptable.

Tom Lyon - 2011/01/31 01:04:34 UTC

How is aerotow done differently in the UK, Mike? Or is hang glider aerotow not done in the UK?

Davis Straub - 2011/01/31 01:06:30 UTC

The chances exist (but are small) on one setup (V-bridle hooked to the keel with weaklink only (no other release up there), pro-tow only release). Not on the pro-tow set up.

Mike Lake - 2011/01/31 01:38:12 UTC

Mechanical chest release in most instances.

Actually the point I was making is that over here a release jam is a very rare occurrence.
The impression I get from the US (from what I read) is that it is not quite such a rare occurrence and is considered more of an occupational hazard.

Davis Straub - 2011/01/31 01:51:44 UTC

A very incorrect impression. But I guess that is the internet for you.

Mike Lake - 2011/01/31 02:10:50 UTC

If you release while under load, the chances of the rope grabbing the tow ring are substantial.

"Substantial"

Tom Lyon - 2011/01/31 03:58:25 UTC

The chances exist (but are small) on one setup (V-bridle hooked to the keel with weaklink only (no other release up there), pro-tow only release). Not on the pro-tow set up.

You're satisfied that the pro-tow set up for aerotow is as safe as the Tost or Schweizer releases used on sailplanes? It looks like it is to me, but I haven't towed that way yet and you must have five thousand tows with the setup.

Davis Straub - 2011/01/31 04:43:37 UTC

I and many others are very satisfied with the pro-tow setup for aerotowing.

Jim Rooney - 2011/01/31 10:47:56 UTC

Pudpud.
A little research may do you some good. You're not following this and you're starting down that annoying old chest crusher debate again... which in addition to being annoying, has nothing to do with this discussion.

The release doesn't fail, the bridal grabs the towrope caribiner as it zings through it. The secondary weaklinks, which were holding 1/4 load, switch to 1/2 load in shock loading and break nearly instantly.

Your lovely chest release would make no difference.

Mike Lake - 2011/01/31 11:55:50 UTC

To repeat my earlier post...

Actually the point I was making is that over here a release jam is a very rare occurrence.
The impression I get from the US (from what I read) is that it is not quite such a rare occurrence and is considered more of an occupational hazard.

Sorry I didn't make myself very clear at all.
In this instance I wasn't particularly referring to the release itself as a "chest crusher", "flappy dangly thing", or otherwise. I have no intention of starting any debate in that direction.

What I should have said was...

Actually the point I was making is that over here not being able to detach oneself from the glider is a very rare occurrence.
The impression I get from the US (from what I read) is that it is not quite such a rare occurrence and is considered more of an occupational hazard.

What you said Jim...

If you release while under load, the chances of the rope grabbing the tow ring are substantial".

"Substantial"
This struck me as a bit too likely whatever the strategy for recovery.

Hopefully with this revision I can now stop annoying people and possibly contribute something at sometime in the future.

Invisible Wave Rider - 2011/01/31 15:22:59 UTC

The tow line to release interface

Jim, as I am starting to play with Elektra Tow (ET) at Quest Air (the battery powered "scooter" tow system you and Adam got me jazzed up about up at Highland) I've watched this thread closely. We all can learn.

Jim, as I am starting to play with Elektra Tow (ET) at Quest Air (the battery powered "scooter" tow system you and Adam got me jazzed up about up at Highland) I've watched this thread closely. We all can learn.

Enjoy your posts, as always, and find your comments solid, based on hundreds of hours / tows of experience and backed up by a keen intellect/knowledge of the issues when it comes to most things in general and hang gliding AT/Towing in particular. Wanted to go on record in case anyone reading wanted to know one persons comments they should give weight to.

Particularly germane to this thread is the towline to tow release interface. Very important, as it was a root cause in this accident (attaching directly through weaklink line on the end of the tow line to the tow bridle, leading it would seem to the bridal line wrapping up / cinching to the tow line and hence failure to release). Jim Praul here at Quest explained a lot about the research / testing on what's best to put on the end of the tow line to avoid the dreaded tow bridle wrap around and cinch issue. Big rings seem to provide enough real estate perpendicular to the tow line that it allows/promotes the bridle to whip around and wrap up as it is passing through. Worse whipping around if you release under high load as you mention and, also as mentioned, too long of a weak link on the release side of the bridle makes this worse as well. Small rings were too small and allowed bunches in the line to catch and not cleanly passing through. Most operations seem to have settled on smallish carabineers on the end of the tow rope. Seem to work pretty well and easy to get / use. As Jim P. explains it (and it seems to make sense) tapered / triangular shapes with the tow line attached on the narrow angle end don't provide a place for the whipping around bridal line to wrap around. The loose bridal line kinda slides right down the tow line to the attachment "ring" and slides right on by without hitting enough of a discontinuity to initiate the dreaded wraparound/cinch maneuver while still providing a big enough hole for a less than linear, tangled ball of bridal line to go through.

So, your thoughts on the topic and what's your favorite tow line / bridal interface?

Mitch

++++++++++

If the bridal gets caugth up in the tow line you could have issues with 1 barrel. I've only seen this happen on scooter tows with a bowling loop at the end of the tow line. I've never had it happen with AT and a metal biner/ring at the end of the tow line.

Bridle? Caught? Bowline?

So apparently in Ohio people are also stupid enough tow in EXACTLY the same manner that caused the jam that got Shane slammed in, watch it happen, and do little or nothing about it. Goes with the language skills.

If you use a single barrel setup, have the weaklink on the other side.

This way you don't have a piece of rope tied directly to you.
Every now and then, ropes like to grab things
Extremely not likely, but... well, why not just avoid the situation all together?

Why not REALLY avoid the situation altogether and:
- use a bridle too short to wrap;
- put weak links on BOTH sides; and
- put releases on BOTH sides?

Why don't we have sane regulations in this stupid sport to make that MANDATORY?

While we were not using a "Pro Tow " setup, on my very first AT lesson the bridle from a Lookout Mountain style release promptly wrapped itself around the towline carabiner prompting an even quicker secondary shoulder release by my instructor.

1. Almost certainly meaning there was no weak link below the tow ring and thus you were towing with no limitation on the tow tension during the emergency.

2. No - the reaction of your instructor was NOT quicker.

In fact, in three weekends of crack of dawn lessons and then ground crewing for the day for the rest of the pilots, the incidence of a bridle tangling seemed almost one in twenty-five to thirty.

Matt Taber - 2009/05/11 22:48:48 UTC

In all of my experience as a pilot -- tandem pilot and tug pilot I have not seen, heard about or experienced this. Is it really an issue or a perceived issue?

Three and a third to four percent, Matt. A hundred percent on Dave's first tow.

The chances exist (but are small) on one setup (V-bridle hooked to the keel with weaklink only (no other release up there), pro-tow only release).

Now seems clearly not a good idea-- really don't want to end up connected only to the keel even for one second, as long as it takes to reach for the spinnaker release handle...

Don't have a cow, Steve. Davis seems to be OK with it.

Not on the pro-tow set up.

---

When we're doing lockout training, the odds go from 1 in 1,000 to over 50/50.

---

Nah, no freakin' way on the "pro-tow" setup. After all, you guys are pros.

But I guess that is the internet for you.

---

In fact, in three weekends of crack of dawn lessons and then ground crewing for the day for the rest of the pilots, the incidence of a bridle tangling seemed almost one in twenty-five to thirty.

When we're doing lockout training, the odds go from 1 in 1,000 to over 50/50.

When Jim got me locked out to the right, I couldn't keep the pitch of the glider with one hand for more than a second (the pressure was a zillion pounds, more or less), but the F'ing release slid around when I tried to hit it. The barrel release wouldn't work because we had too much pressure on it.

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

---

Yeah Davis, that's the internet for ya. Just can't find good information anywhere.

I and many others are very satisfied with the pro-tow setup for aerotowing.

---

Under weight of these observations, I do attest that TAD's RELEASE is SUPERIOR to the BAILEY RELEASE and that the BAILEY RELEASE is SERIOUSLY FLAWED UNDER HIGH LOADS.

The barrel release wouldn't work because we had too much pressure on it.

By the time we gained about sixty feet I could no longer hold the glider centered - I was probably at a twenty degree bank - so I quickly released before the lockout to the side progressed. The glider instantly whipped to the side in a wingover maneuver.

The basebar hit the ground first, nose wires failed from the impact, and at the same time she was hitting face first.

I have never had a lockout situation happen so quickly and dramatically and had no chance to release as I have always thought I could do.

Hurt hang glider pilot joked bravely with friends after a crash landing, unaware that his injuries were fatal.

The pilot launched with his Litespeed and climbed to about forty feet when he encountered a thermal that lifted him well above the tug. After a few moments, the glider was seen to move to the side and rapidly turn nose down to fly into the ground, still on tow, in a classic lockout maneuver. The impact was fatal.

---

Yeah Davis, there's practically nothing that you and other assholes AREN'T very satisfied with for aerotowing.

A little research may do you some good. You're not following this and you're starting down that annoying old chest crusher debate again...

Hey Jim, why don't you shut the fuck up until YOU'VE done a little research and found an example of a chest crusher actually crushing a chest.

The Civil Aviation Authority (CAA) is urgently pushing for new hang-gliding industry standards after learning a hang-gliding pilot who suffered serious injuries in a crash three weeks ago had not clipped himself on to the glider.

Extreme Air tandem gliding pilot James (Jim) Rooney safely clipped his passenger into the glider before departing from the Coronet Peak launch site, near Queenstown, CAA sports and recreation manager Rex Kenny said yesterday.

In a video, he was seen to hold on to the glider for about fifty meters before hitting power lines.

Rooney and the passenger fell about fifteen meters to the ground.

The passenger, believed to be a tourist in her twenties, suffered minor to moderate leg lacerations.

How 'bout instead we start referring to you as a passenger slasher - 'cause we have the data to justify that.

---

The barrel release wouldn't work...

Holly's face wasn't just cracked in a few places, it was shattered into many pieces over large areas.

Elliot shattered four bones in his neck and damaged several blood vessels that supplied blood to the brain. He was flown to the Royal North Shore Hospital in Sydney and put into an induced coma but died on Monday.

The impact was fatal.

---

How 'bout we call the pro-tow setup a jammer, face smasher, neck breaker, or aerodynamic engineer killer? That OK with you, Passenger Slasher?

The release doesn't fail...

---

The barrel release wouldn't work because we had too much pressure on it.

---

...the bridal grabs the towrope caribiner as it zings through it.

On a two point system that's an inherent weakness. On a one point it is a design flaw and - yes - a RELEASE FAILURE.

...which in addition to being annoying, has nothing to do with this discussion.

Ignoring the fact that the title of this thread is:

What can be learned from this "scooter" towing accident?

and this "ACCIDENT" would not have happened with a Koch two stage.

Your lovely chest release would make no difference.

Except that Shane would now be healthy and looking for some other way to kill himself at this time.

I have no intention of starting any debate in that direction.

Too bad, 'cause that's the debate we need to be having.

...and backed up by a keen intellect/knowledge of the issues when it comes to most things in general and hang gliding AT/Towing in particular.

KEEN INTELLECT???!!!

---

...bridal grabs the towrope caribiner...

Bent pin releases are indeed very very reliable.

Aerotowing is a static system, I can snap that weaklink at will.

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.

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

A tandem hang-gliding pilot was in hospital with serious head injuries last night after the crash, which is the latest in a series of incidents involving Queenstown company Extreme Air that have prompted Civil Aviation Authority (CAA) investigations.

There isn't one sure-fire answer. If there was, we'd all be doing it already.

---

Wanted to go on record in case anyone reading wanted to know one persons comments they should give weight to.

---

The passenger, believed to be a tourist in her twenties, suffered minor to moderate leg lacerations.

---

How 'bout we get a second opinion on that?

...leading it would seem to the bridal line wrapping up
...settled on smallish carabineers...
...the whipping around bridal line to wrap around...
...The loose bridal line...
...tangled ball of bridal line to go through...
...bridal interface...

Maybe it's something in the water on the Delmarva Peninsula and/or in central Florida.

So, your thoughts on the topic and what's your favorite tow line / bridal interface?

How come NOT ONE of you fucking morons is discussing the bridLE construction or LENGTH???

http://www.flickr.com/photos/aerotowrelease/8306152861/


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

(Please don't be Mitch Shipley - I thought he was smarter than that.)

[Tad Eareckson]

Hey Larry,

VERY happy to have you on board.

I'm a pessimist...

Goddam right you are. Hang gliding sucks 'cause 99 percent of its participants are optimists. This forum exists exclusively for rabid pessimists who won't take a one in a million gamble if there's absolutely no reason to do so. Robin Strid was killed in a one in a million alignment of the negatives that hang gliding optimists work so hard to maintain. I will ban any optimist that rears his ugly head here in a New York minute.

...but I do still assume that component can fail and I will have to tuck myself in to a ball with my head down and try to survive that if I'm low.

Me too. Totally on board with that. If I separate from my glider and harness at five thousand feet I'm gonna try to learn enough freefall technique in the next in the next two minutes to get myself over a pond (assuming I'm not totally paralyzed with terror - which I probably will be).

...and I think engineering the process is more valuable than engineering hardware...

Not sure I understand that.

...but still don't think there is any release that doesn't have a failure mode.

And I'm still saying that there never has been or will be a failure of a hang gliding - or sailplane - release that wasn't due to an obvious and predictable design, setup, maintenance, and/or preflight failure.

Look at this last one, for example. Absolutely infuriatingly obvious and stupid. I know I'm probably a rotten person for saying this but I don't think I've ever felt less sympathy in any hang gliding crash than for the casualty and the people involved in that situation. (But I'm holding out hope that Davis, Jack, and/or Jim Rooney will lower the bar another two or three feet.)

The release Shane was using (barrel/pin) is one I wouldn't trust AT ALL (I send people links to your image library to back that up)...

1. Thanks.
2. Even with the crap they were using they'd have been in good shape if they had just left the goddam carabiner on the towline.
3. But the Koch two stage is still better than anything I've developed that would be ready to go for that kind of towing.
4. And the goddam Koch two stage has been around since at least 1985.

...but turning away from the line while still attached is NEVER a response I train.

The driver's ed equivalent being - don't drive into a tree.

Yeah, sounds like he had no plan at that point - but this group didn't have any plans for anything to begin with.

Looking forward to reading things over here after getting frustrated reading over on Oz and HG.org.

Those dumps are huge parts of the machinery to keep anything from ever getting better.

Thanks for putting this up.

I was gonna do something like this myself some day but... Thank Zack. (And he's a much better geek than I am.)

I've been trying to conceive of a inline "line cutter" squib that would be cheap and easy to fire off from either end under certain conditions, but haven't found the tech that I would trust yet.

1. I've looked into adapting my AT system for something like this using radio control and it would be pretty easy.

2. Jim Prahl actually put something in the air.

3. But I talked to him about it and he had concluded that it really didn't represent much/any advancement.

4. I concur.

- You can kill someone by pushing the button at the wrong time.

- The pilot is the one in the best position to make the call and it's his ass.

- Even if the pilot's never been near a glider before this - his first day of training - he's still the pilot and it's still his call and his ass. If you're the instructor your job in to keep him out of situations that can become critical.

- It's a thousand times better to let the pilot kill himself than for somebody on the ground to kill him.

- If you want him radio controlled put some speakers in his helmet so he can be advised - but don't expect much better results if he really doesn't know what he's doing to begin with.

I want to be able to disconnect from the line reliably if the release jams or the operator passes out, but then would have to develop a plan for dealing with THAT failing.

Logic is a bitch.

Tommy Crump - 1986/10

There are some things that you must rely on hundreds of thousands of times without failure. A release mechanism that is properly designed can do that.

My take...

- Despite all the crap you hear in hang gliding it takes additional engineering complexity to make release systems safer.

- Engineering complexity is not to be confused with non engineering complexity. It was non engineering complexity which caused Lauren's Bailey and Robin's Wallaby to lock up.

- You're talking about engineering potentially dangerous complexity into a tow system to compensate for an inadequately engineered absolutely critical component - the release.

- Focus on making the release (and the pilot, another absolutely critical component) absolutely bulletproof. More bang for the buck, no potential downsides.

[Zack C]

Welcome, Larry...good to see a post from someone other than Tad and me.

Tad, if you put every post related to releases in this one topic, it's eventually going to get very hard for newcomers to follow it. I think the Shane incident discussion should have been a separate topic. We can create a 'Tow Releases' subforum to put all release-related discussions in if necessary. JMO.

There needs to be some basic Boy Scout knots and line stuff in the Hang One requirements and on the test.

Yeah, I've never spliced rope or even stitched anything in my life (I suck with knots too...took me years before I started consistently getting the orientation of the overhands in Fisherman's Knots matching on the first try). I'll admit they're skills I should pursue, but I'm not going to start practicing them on things my life depends on.

The ONLY time you need to replace a bottom end weak link is after it blows following a wrap.

Even if it's string? I'm worried about the stuff wearing over time and I surely don't want the bottom end breaking before the top. 20% over the upper weak link isn't a big margin. I'm still going to replace the top periodically (though not as frequently as I was)...seems like when I do that I should replace the bottom at the same time.

I think I wasn't following your intent regarding the weak link on the bottom end of the primary bridle. When you first mentioned it I thought you were talking about duplicating the function of the weak links on the secondary bridle, which is why I didn't see the need for both. If I understand you correctly now, having a ~1.5G secondary bridle isn't so much to release automatically in the event of a primary wrap (the function of the weak link on the bottom end of the primary) but to protect from equipment failure in the event of towing single-point (whether due to a wrap or intentionally). But you can reduce the strength of the secondary bridle weak links to make them serve the same purpose as the primary bridle bottom weak link so long as you don't tow one-point with them. Is my understanding correct? I was under the impression from what you said before that even a 1.5 G secondary weak link would likely break in the event of a primary wrap.

I'm not sure if I like making the secondary bridle break just above the top weak link. The reason is that I'm worried about it breaking before the top (as happened to Jackie B, although the setup details of that incident are unknown). Were this to happen, the thimble would have to feed through the tow ring. I'm not sure what complications this would cause if any, but I don't want to discover them the hard way. If the weak link is instead around the thimble and it broke before the top one, the thimble would stay on the secondary (and hopefully the primary wouldn't wrap...). Having said that, I have much more confidence in the longevity of your Bridle Links than string weak links.

I don't think the primary bottom weak link would be a big deal, really.

If we can find a few more increments of light line like that... Maybe just two - 250 and 300...

What if? I'm not following you here.

At any rate, Stuart Caruk sells line in 250, 300, and 400 lb flavors.

Good wrap resistant hollow braid Spectra bridles you can do in your sleep.

I hope by 'you' you don't mean me!

1. We're even.
2. Freudian?

About the three-string premature release...

The bridle was stretching and getting longer.

I was aware of this type of issue and have actually seen it cause a premature release, but it happened pretty soon after launch. It seems like if this was the cause, it would happen frequently. I'm wondering if something did in fact pull the lanyard...like I said, it doesn't take much to trigger the release.

What material is being used for the bridle? Nylon?

Don't know and don't know how to tell. Here's a pic (the black being the bridle) in case it tells you anything:

YOU ABSOLUTELY CANNOT OPERATE THIS WAY.

Which is why I quit using that release.

About our tug...

Is an extension of the towline routed through the propeller shaft?

Not sure what you mean...the tow line connects to the release, which sticks out the propeller shaft. From my memory, the release looks sort of like the snap shackles at the shoulder loops on your release photos...curved gate hinged on one side with a spring loaded pin on the other going through a hole in the gate to keep it latched.

Do they do tandem?

They generally don't do tandems at Columbus because the runway isn't long enough for the tug to land safely in the event of an engine failure shortly after takeoff given the slower climb rate with a tandem. But I know that our tug has pulled tandems before.

The front end of the towline would be a REAL GOOD place to put one of my Shear Links...

Yeah, but our club members voted to ban you...I expect they'd be much more receptive to Tost weak links than something from your 'black magic workshop'.

Zack

[Tad Eareckson]

Tad, if you put every post related to releases in this one topic...

It's always hard to keep these discussions organized. Releases, weak links, lockouts, stalls, fatalities, even suspension... Overlaps, gray areas, blurring, tangents...

Yeah, I knew from the start that things were gonna get somewhat unwieldy - and they have - but I'm not real worried about where we are now. It's well written, well organized, searchable, and quotable. But if you think you've got better ideas I can be lead by the nose fairly easily.

...(I suck with knots too...took me years before I started consistently getting the orientation of the overhands in Fisherman's Knots matching on the first try).

In case you don't know this already and/or for the benefit of anyone else...

Do the first Overhand over the other end of the loop, flip the loop (yaw it 180 degrees), and tie the second Overhand exactly the same as you tied the first one.

I'll admit they're skills I should pursue, but I'm not going to start practicing them on things my life depends on.

1. Do you know how incredibly dangerous your AT bridle/release system was prior to these discussions? It would be pretty tough to go any direction but up.

I had a very different mindset too back then and trusted the people that made my equipment. Since then I've realized (largely due to this discussion) that while I can certainly consider the advice of others, I can't trust anyone in this sport but myself (and maybe the people at Wills Wing).

2. If you want some of this stuff done right you're gonna hafta do it yourself - like I did. And at this time you're not gonna get any help from Wills Wing.

http://groups.yahoo.com/group/skysailingtowing/message/4411
Keel Attachment

John Moody - 2004/12/16 23:07:36 UTC
Conroe, Texas

What is not normal is to see a factory-made glider that has a built in nose attachment or keel attachment or even the keel release built-in, faired and clean - like a VG system is.

So why does Mr. Reynoldson have to ask where to attach his tow line? ATOS has to know that their gliders are being towed every day. Why does each pilot have to figure it out, one at a time. Why don't the manufacturers sell a TOWING version of their gliders and avoid someone getting it wrong?

Cc:
tx-hg@yahoogroups.com
AustinFreeFlight@yahoogroups.com
houstonhg@yahoogroups.com
aerotow@yahoogroups.com

3. So don't start practicing them on things on which your life depends. Start practicing them on scraps of line while you're vegging out in front of the television. Like I said, I practiced Dvorak on an unplugged keyboard and, after a couple of months, sucked at it no worse than I did at qwerty after forty years.

Even if it's string?

Yes. I flew for years with a loop of 205 leechline at the bottom end of my bridle. And I'm a lot heavier than you are and have locked out a whole lot more than you have. It's not getting stressed. It's especially not getting stressed when you've got something lighter at the top.

I'm worried about the stuff wearing over time...

1. It doesn't wear. There's nothing to wear it. And if it did wear you could easily see the wear.

2. And Dacron doesn't give much of a rat's ass about UV - especially if you put your harness back in the bag when you're not in it and don't leave it on the field baking in the sun all afternoon.

3. IF anything's gonna wear and/or degrade it's gonna be your primary. Self correcting problem.

20% over the upper weak link isn't a big margin.

So go higher. Like everything else in aviation, it's a tradeoff. The closer you get to the upper the less the likelihood you'll ever hafta deal with a wrap. The further you get the less you hafta worry about a tuck - to a point. At some point the chance of the lower one blowing first becomes ZERO and there's nothing but downside to going higher.

With my Shear Links testing and tolerances I felt confident using and recommending twenty.

Plus... I've got a primary release in which I have one hundred percent confidence and if I do ANYTHING with my left hand the problem's over. And - based on accounts of people pulling Lennies - I'm confident that I can react in plenty of time to deal with things.

I'm still going to replace the top periodically...

Don't. That's 130 Greenspot mind-set. Put a magnifying glass on it once a month if in makes you happy. If there's nothing significant in the way of broken fibers leave it alone.

Remember, if you shoot for 1.5 Gs you're gonna end up somewhere close the middle of a very wide target. Even if a 250 pound loop becomes 200... So what? You go from one and TWO thirds to one and ONE third Gs. BFD. Plus you widen the margin between top and bottom.

And 1.5 itself is a somewhat arbitrary figure.

Don't get too anal. And this coming from one of the most anal jerks on the planet.

Also - With all those disclaimers on the release you're using now...

I think I wasn't following your intent regarding the weak link on the bottom end of the primary bridle. ... Is my understanding correct?

Yep.

If I understand you correctly now, having a ~1.5G secondary bridle is ... to protect from equipment failure in the event of towing single-point (whether due to a wrap or intentionally).

The "equipment" - in this less than ideal state of technology - primarily being the release(s) and "failure" meaning overload and/or damage.

I was under the impression from what you said before that even a 1.5 G secondary weak link would likely break in the event of a primary wrap.

No, I'm pretty sure I never said that - although I wouldn't bet on it holding. What I can tell you is that Sunny told me that on a tandem the blowing of a double loop of 130 on the end of a secondary bridle following a wrap is a virtual no brainer.

The reason is that I'm worried about it breaking before the top (as happened to Jackie B, although the setup details of that incident are unknown).

The Jackie B (Tom Lyon) thing was a freakin' atrocity.

I'll tell you EXACTLY how that crap was configured.
- Quest primary, lever on the right downtube
- Double loop of 130 on the top end of the primary bridle
- Bottom end of primary bridle chewed up by middle inch of four foot secondary bridle
- Middle inch of four foot secondary bridle chewed up by bottom end of primary bridle
- Bailey release on right shoulder
- Right end of secondary bridle connected directly to Bailey
- Left end of secondary bridle connected to left tow loop with double loop of 130

Every time there's a fluctuation in tow tension the secondary weak link tightens and eases on the tow loop and abrades just a little bit.

Eventually, after the degree of abrasion becomes ridiculous, the secondary becomes the primary - big time.

Freakin' assholes.

Were this to happen, the thimble would have to feed through the tow ring. I'm not sure what complications this would cause if any, but I don't want to discover them the hard way.

I don't design for this happening 'cause there's no good excuse for it happening. Kind like Wills Wing doesn't design gliders to recover from flying into radio towers.

I keep that end as wrap resistant as possible anyway in case it does but that's not the primary design goal of that end of the bridle. That end of the bridle is designed not to chew and be chewed - to reduce the likelihood of a bottom end separation and subsequent wrap - and to optimize the performance of the secondary system - like Shane DIDN'T - in the event of a top end wrap.

Were this to happen, the thimble would have to feed through the tow ring. I'm not sure what complications this would cause if any...

Highly likely none. Worse than the possibility of a wrap of just the bridle fer sure - but that ain't zero neither.

...but I don't want to discover them the hard way.

Then do what I do. Configure so that it can't happen.

If the weak link is instead around the thimble and it broke before the top one, the thimble would stay on the secondary (and hopefully the primary wouldn't wrap...).

Correct. But you haven't plugged everything into the equation.

If you deliberately blow a secondary release because your Lookout Special does what the owner's manual says it will or one is accidentally triggered, the bottom end of the primary bridle is now MORE likely to hang up.

Having said that, I have much more confidence in the longevity of your Bridle Links than string weak links.

The Bridle Link's gonna be better but not enough to matter. The main advantage here is that you very likely can dial in a better number than you're likely to land on using string.

Stuart Caruk sells line in 250, 300, and 400 lb flavors.

Yeah, he does. I somehow managed to miss that.

There's a Western Filaments that does 250 - I wonder if that's what he's got.

250 is probably what you want. On the top end of your primary bridle that puts your Sport 2 - fully loaded - at 1.4 Gs. One point, 1.6. At your flying weight, 1.7 and 1.9.

Respective numbers for the 200 you're using now: 1.1, 1.3, 1.3, 1.5.

Maybe use 250 two point and 200 one. 150 on the ends of your secondary when using it as a secondary.

I hope by 'you' you don't mean me!

Yeah, I can make you one you can use and - after I get hit by a truck - reverse engineer and duplicate to keep the technology alive.

I'm wondering if something did in fact pull the lanyard...

There aren't a whole lot of possibilities. Shouldn't take Hercule Poirot to narrow them down.

Don't know and don't know how to tell. Here's a pic...

Almost CERTAINLY nylon. Hook the release to a carabiner, hook the carabiner to a chain around a tree, pull on the loop at the end of a bridle half. If it stretches it's nylon.

Which is why I quit using that release.

Just replace the bridle with something inelastic and short and anchor it - and the lanyardS (one on each side) at your tow loops.

Not sure what you mean...

What I mean is... Is there any possibility of the towline twisting at a rate of 5000 rpms? If so, you need a swivel.

From my memory, the release looks sort of like the snap shackles at the shoulder loops on your release photos...curved gate hinged on one side with a spring loaded pin on the other going through a hole in the gate to keep it latched.

Which has been tested to operate at what loading and to what angles?

The United States Hang Gliding and Paragliding Association, Inc.
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
10. Hang Gliding Aerotow Ratings
-B. Aero Vehicle Requirements

04. A pilot operational release must connect the tow line to the towing vehicle. This release must be operational with zero tow line force up to twice the rated breaking strength of the weak link.

Yeah, right.

"Oh, if Zack had JUST used a SANE WEAK LINK like everybody else Mick's wonderful wife and fifteen adorable children would still have a loving husband and father coming home every night. We all hope you're REALLY HAPPY now, Tad."

They generally don't do tandems at Columbus because the runway isn't long enough for the tug to land safely in the event of an engine failure shortly after takeoff...

Yeah, tug drivers don't like it when THEY have power failures shortly after takeoff...
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://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.

Yeah, but our club members voted to ban you...

Slightly over half of your club members voted to ban me. Slightly over a quarter voted to keep me. Half of your tug drivers voted to ban me and the other half - Gregg - voted to keep me.

I expect they'd be much more receptive to Tost weak links than something from your 'black magic workshop'.

Tell 'em it's the latest thing from Lookout. Five or six people should be crushed in the stampede to be first to use, adore, and worship it.