US Hawks Hang Gliding Association

Wallaby Ranch - 2011/04/17

If you fail to maintain the correct tow position (centered, with the wheels of the tug on the horizon), the weak link will break before you can get into too much trouble.

axo - 2009/06/18

I have had one weak link break during launch and I feel "lucky" everything went well and just landed a bit hard on the wheels.

But I also saw a world class pilot having exactly the same problem and breaking the link at the same altitude. But he broke the downtubes on his Litespeed and looked to be in pain in one of his wrists. He was fine though.

I saw more weak links break at low altitude and it is always a few seconds of anguish and uncertainty about what's gonna happen to the pilot.

Wallaby Ranch - 2011/04/17

Remember: it is almost impossible to stall under aerotow. The induced thrust vector makes the glider trim at a higher attitude. It is OK to push way out; you will climb, not stall.

Sergey Ka - 2006/05/23

I have aerotowed recently, my first three times. Wasn't allowed to use my mouth release (got the proper type which opens when you open your mouth) because the club uses Wallaby ranch style V-bridle. I've been really worried about releasing in a critical situation.

Also it didn't help my confidence that the particular top release was very hesitant to open - it took about three seconds of squeezing the bicycle brake type lever to open the release.

axo - 2009/06/20
Miami Beach

I always check my spinnaker shackle hook and the cable. Mine is still pretty much new and has worked perfectly.

But I have seen others fail twice and one of them was during one of my training tandems. I just kept hitting the brake lever for a few seconds in WTF mode, and the instructor used the barrel release.

Davis Straub - 2005/01/10

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.

This type of release mechanism has been banned (at least for a short while) from the Worlds at Hay.

cecilbunter - 2009/06/12
Illinois

Wallaby ranch has accidents.
They are kept very quiet.

Jack Axaopoulus - 2009/11/09

Tad, your continual bashing in general and bashing of HG schools has gotten really old. AT parks have solid safety records, so what you say and reality seem to be quite far apart.

You dominate the ignore report here http://www.hanggliding.org/ignorereport.php
Ever ask yourself why???

You do nothing but bring negativity here. My finger is on the ban button.
This is your last warning.

If you continue rubbing everyone the wrong way with your harsh, know it all tone, you are out of here.

Jacmac - 2009/11/16

Fatality at Wallaby

Alfie Norks - 2010/06/03
Brazil

Speedy recovery to the pilot in question.

It could have been worse. It could have happened at...the other place (but nothing happens there). Good luck if it does. No 911 calls allowed. My friend was lucky, the nurse on hand convinced the owner not to move him, this after he snatched and threw her phone away. She was trying to dial 911. My friend suffered lower back injury.

Helen McKerral - 2010/06/23
South Australia

If this is true, and can be substantiated (were you a witness?), then the place should be outed, reported to the relevant National umbrella org, and the owners have the book thrown at them.

fly,surf,&ski - 2010/06/23
Torrey Pines

In the U.S. our national org tends to view these kinds of things as a "Local Issue".

Sam Kellner - 2010/03/28

Yeah, I don't even read all of those long winded "explanations".

Sam Kellner - 2010/04/02

Tad's release

Would/could not release at all. No better than any others.

Bart Weghorst - 2011/02/25

But I've had it once where the pin had bent inside the barrel from excessive tow force. My weaklink was still intact. The tug pilot's weaklink broke so I had the rope. I had to use two hands to get the pin out of the barrel.

No stress because I was high.

Sam Kellner - 2010/04/03

When you pull your release and nothing happens , and you shitt your pants, then you will know how!

Yep, I have ABSOLUTELY NO DOUBT WHATSOEVER that if Sam really works at it there WILL BE another Wallaby Ranch in Leakey - also doing whatever the phuck it feels like with no long winded "explanations" to read, theory to understand, bothersome training and safety standards and advisories to follow, or meddlesome national umbrella organization to answer to. Is this a great country or what!!!

Need any help? I can throw an iPhone 4 seventy-five yards into the wind with no warm-up on a bad day.

More Kool-Aid anyone?

You got the fu**ing gall to ask me that after what you did a year ago on my final exchange on the Oz Report?

OK, one of the most important of the many constructive and supportive things I do for hang gliding is identify stupid, dangerous, and evil people in hang gliding who - by what they teach, set as examples, advise, sell, do, and don't do - are major threats to other people.

I'll be more than happy to provide lists and answer any other questions you might have.

I just posted on this thread to make sure I got noticed this time. I'm gonna leave it alone now, wish Sam well on his soaring forecast efforts, and continue back at "Conflict of Interest". (Kinda like that part of the title 'cause it really hits the nail on the head with respect to a huge chunk of what's wrong with hang gliding.) I suggest folk head over there and pay attention.

We ALMOST ALWAYS have enough margin and/or redundancy in these situations to come out smelling like roses and thus the hang gliding community considers them no BFDs, occupational hazards, costs of doing business. Then we continue right along as we always have until someone gets killed a year or two later, blame the pilot who just froze, made no effort to release, shouldn't have been flying in those conditions at his skill level, and take a flight in his honor on the same equipment.

There's stuff I can't see and don't know about this configuration and tow but we do have several good, proven, time honored ways to kill ourselves here.

It was a super tow to cloud base ~2500'.

I'm guessing payout winch? Hopefully platform launch since this isn't a two stage release.

As the tow vehicle neared the end of the runway...

Still maintaining full tow tension / pressure gauge reading or slowed down / backed off? I'm guessing the former.

I glanced down to visually locate the release pin line.

Is that a luxury your gonna be able to afford when the shitt's hitting the fan down low?

Maybe two seconds later...

That can be a very very long time when the shitt's hitting the fan down low. That can be the rest of your life.

I felt a normal thump of release...

Suggesting that you WERE still under normal climb tension.

...and the tow line fell away.

So you didn't hafta spend the next forty-three seconds hacking away with your hook knife the way Todd did at similar altitude a bit over a year ago.

http://www.hanggliding.org/viewtopic.php?t=16384

WTF ? Mind controlled release ?

No, weak link failure.

Here's what was left attached when I landed...

Was the (three-string?) release recovered from the end of the towline?

Not relevant to this situation but... The bridle appears to be Perlon. Bad idea. You want low stretch (Dacron, Spectra) and short - going to tow loops versus carabiner.

Where's the lanyard anchored?

The lanyard's only going to one side. Why not run lanyards to both?

What would be the downside to having a pair of barrel releases at your hips?

If you had used a Koch one stage (or two stage used as a one stage) would you have been able to actuate it a little faster, without having to look for a trigger?

At what tension did you launch and how much tension were you feeling at the top?

How much line was out?

What was the weak link strength and why?

What was your glider model and size and your flying weight?

Can you imagine being in a situation in which things could get really really ugly if that weak link blew at the tension you were feeling when it did?

You're using:

- an actuator that you've gotta look for;
- an actuator that, at altitude with the glider level and trim and everything normal and on schedule, you are unable to trigger after the second hand has ticked a couple of times;
- an actuator that requires you to take a hand off to blow while you pretend to be able to fly the glider with the other - possibly while fighting a lockout;
- a weak link that blows under normal tension.

People have died for all of those reasons individually. You've got them all stacked together. Gonna do anything differently next time or the same - 'cause this is the way everybody's always done it - and expect different results?

Sorry, couple more thoughts on this situation.

Ya know what's REALLY DANGEROUS about this tow?

For the past three decades the total morons who control this sport - national organizations, book authors, magazine editors, forum moderators, flight parks, schools, tug drivers, competition organizers - have been programming the total morons who participate in it to believe that ANYTHING and EVERYTHING BAD that starts happening on tow WILL BE nipped in the bud with "a properly applied weak link" (Towing Aloft - Page 334).

And you can always find plenty of examples in which "a properly applied weak link" DOES blow "AS IT'S SUPPOSED TO"...

Chris McKee - 2008/05/25
Ridgely

Expecting to add to my long list of sled rides this year, I was surprised just how much thermal turbulance was out there on tow. At 2200 feet, I watched as the Tug rocketed up and my glider joined the space shuttle launch a few seconds later. I fell out of the thermal in a hard right turn and knew I had no chance to get back wings level. As I reached for my release, the weak link snapped (AS IT'S SUPPOSED TO) and suddenly I was off tow. I followed the ensuing hard right turn around 270 and entered the thermal that had just bucked me and continued by climb up to 5500 feet.

...for some some total moron while he's reaching for his very very reliable bent pin release and pretending to control the glider with his other hand at 2200 feet where there's no airport to come up and smack him while he's following the ensuing hard right turn around 270.

And then we can continue to ignore the Dave Garrison, Chris Bulger, Richard Graham, Debbie Young, Dick Reynolds, Frank Sauber, Rob Richardson, Ralph Sickinger, Mike Haas, Robin Strid, Holly Korzilius, Arlan Birkett / Jeremiah Thompson, James Simpson, John Dullahan, Lauren Tjaden, Carlos Weill, Steve Elliott, Roy Messing, Shane Smith situations in which "a properly applied weak link" DOESN'T blow "AS IT'S SUPPOSED TO" and keep on using the same shitrigged equipment.

And a little more on that aspect of the issue...

As the tow vehicle neared the end of the runway, I glanced down to visually locate the release pin line. Maybe two seconds later...

As my car neared the intersection a truck ran the red. I glanced down to visually locate the brake pedal. Maybe two seconds later...

As my kid neared the end of the driveway a car was speeding through the neighborhood. He glanced down to visually locate the brake lever. Maybe two seconds later...

This is TOTAL bulls***. There's no freakin' way sane people back in the REAL world would tolerate crap like this. That was a TOTAL RELEASE *FAILURE*.

You wanna get off in ANY circumstances, two seconds later you're still on - that's a FAILURE. Start recognizing it for what it is and do something about it - something that DOESN'T involve using a more properly applied weak link or some clown on the back of the truck with a machete.

It's a bent pin that was straightened release...

Yeah, thought they looked a bit suspicious. Seems like it would make more sense to start out with straight pins but I guess the thinking is that they'd be pretty easy to bend back to the original shape to use for Bailey releases.

I thought this would topic would spark your interest.

Always. Too bad hang gliding has never managed to evolve to the point at which it's way less interesting and way more fun.

No the release was not connected to the tow line.

Yeah, at one point in my thinking I knew that but the light went back out while I was crunching the concept of putting a weak link downwind of the release.

...after the weak link performed as designed...

So what's that weak link "designed" to do? Yeah, I know, blow - but at what point and to accomplish what?

Ignoring the strength of the weak link and the actuation system for the moment... That's a safe but stupid design. You shouldn't hafta lose your release (as well as your tow) every time you blow a weak link (which should be never anyway).

For a three-string I kinda like what Zack's crowd is doing. Make the loop that engages the tow ring the weak link.

Have you heard of "topping off the tow"?

Yeah, even done it a few times - which is why I'm at a loss to understand how a weak link could possibly blow while one was at the point of completion and working on separating voluntarily.

I don't have a whole lot of truck tows and the highest I ever got was only a bit over fifteen hundred feet.

Yeah, I was surprised at the tension Zack guessed he was feeling near the top of tows. Granted, he's probably often lifting a lot more line than I did but I woulda thunk the drivers would be pretty good at backing off on the brake pressure to compensate a bit.

But, what the hell, it's not a safety issue and probably doesn't make any appreciable difference in the efficiency of the tow.

You didn't have a "release malfunction" - in the sense that it did exactly what it was designed to and you were instantly / cleanly / completely separated from tow... But:

1. I've never before heard of a configuration that automatically costs you one release mechanism per weak link failure - in hang gliding, paragliding, or sailplaning.

2. I'd have thunk that the reason you had decided to release at that point was 'cause that you were no longer climbing and that the reason you were no longer climbing was 'cause the tension had dropped to the point of uselessness.

3. Despite all the total rot taught by the morons running the flight parks and published in works of fantasy like Skyting and Towing Aloft, a weak link has one function and one function only - to blow before the glider does in a really rare and extremely ugly situation in which the people have almost certainly totally lost control of the tow a long time ago. Weak links which fail in routine circumstances are expensive and dangerous.

I'll ping Zack and let him know about this discussion.

Thanks.

It was a super tow to cloud base ~2500'.

With a good winch we might get 1000' max.

1. So either that was a super tow not at your local airfield or a super tow to over a fifteen hundred feet shy of cloudbase followed by a climb to cloudbase.

2. I know that aerotowing is expensive and a royal pain with all the tug driver regulations nowadays but it sure is nice being able to go as high as and wherever you want (and not having to deal with all the rewind issues).

3. Stu Caruk (http://www.towmeup.com) is probably a real good place to start for a winch. Ain't cheap but my guess is that the more you pay at the beginning the less you're gonna pay down a rather short road.

4. And there's no doubt whatsoever that people have died 'cause people were towing static instead of using a payout winch.

There's some about tow forces I do not understand, at least unable to discuss in correct terminology.

That's key. I overshot a field on my third mountain flight 'cause my idiot "instructor" didn't know the meaning of the word "turnpoint".

The force that took my release did not feel excessive. It did not even feel unsafe.

A weak link blow is SUPPOSED TO BE like a parachute deployment.

1. It should never happen in the course of an average pilot's flying career.

2. With rare exceptions, it should only happen after a pilot has screwed a couple of pooches bigtime.

3. The pilot should be scared shitless just before it happens.

4. The pilot should not expect to live if it happens down low.

Need a number. From your photos my best guess is that the weak link is 5/64 inch / 205 pound Dacron leechline. That's gonna blow at about two hundred pounds - which would be pathetic - and does seem consistent with what you reported feeling.

Zack's crowd is using a loop of 205 Lark's Headed onto the tow ring loop of a three string release. It thus becomes an extension of the tow ring loop so you just ignore it and connect your three string normally. I'll attach his photo.

Zack claims it blows around six hundred pounds and - although I haven't tested it myself - that sounds about right. And that's a pretty good one-size-fits-all number.

I would advise that you connect your remaining release directly to the bridle and duplicate Zack's configuration.

And if you have other ideas for weak links I'll be more than happy to load test them for you if you don't have a test rig.

Something I'd like to know more about as a PL pilot.

Platform, reel-in, foot, static, aero... The weak link has only one function and it only cares about the strength of the glider, not the flavor of the tow. And thus you use the same weak link for your glider, regardless of the flavor of the tow (despite as the crap you/we've been fed).

It might be a safety issue without a weak link.

1. Nobody with half a brain or better advises towing ANYTHING without a weak link. But there's a tradition in hang and para gliding that Donnell seems to have founded that you either use a weak link of one G or less - preferably WAY less - or nothing at all. Nobody ever died from using a two G weak link and a two G weak link is never gonna blow in the real world.

2. I don't really like to see "safety" used in the same sentence with "weak link".

Steve Kroop - 2005/02/09

A weak link is there to protect the equipment - not the pilot. Anyone who believes otherwise is setting himself up for disaster.

Steve's actually pretty clueless on weak links - he's a 130 pound Greenspot clone - and I had to patch up his grammar for that quote - but that does express the issue REALLY WELL. All the weak link can and will do is limit the stress on the glider in the air under positive loading - and it doesn't give a rat's a** what happens to you - or the glider - before or after that predetermined stress limit is reached.

3. Statistically you're never gonna be in a situation in which a weak link of any rating is gonna do you any good. Got a choice between losing the weak link and losing the wheels... Lose the weak link. No brainer.

4. Choice between a weak link of one G or less or no weak link... Again, lose the weak link. No brainer.

But, it's called "topping off the tow", for a reason.

Absolutely no reason to have (or excuse for using) a weak link which will blow while anyone's topping out a tow.

I thought sure the loop of smallest diameter line would have been the "weak link".

Of course you're stepping down the tension with each loop so - not unless it's deliberately designed that way which, in my opinion, would be an idea second in crappiness only to your current configuration.

Start off with 400 pounds towline tension, the tow ring loop transmits 200 to the middle loop which transmits 100 to the trigger loop which transmits 50 of side loading to the pin. In the real world however - due to the stiffness of the material and friction - the numbers drop A LOT FASTER than that and make the release dysfunctional at low tensions. That's usually no BFD but since a barrel release has excellent performance over a huge range - when it's on the end of a bridle, from under four pounds to over seven hundred of towline tension no sweat - I don't see any point to using three-strings. (Plus there's no significant abrasion/wear involved in barrel release actuation.)

...the only one that protected me with a weak link break.

It didn't protect YOU - see above. And if it left you with the impression that it did, it actually accomplished the precise opposite.

I'm thinking the force comes from somewhere and not really line weight or line drag.

Mostly the truck.

I was climbing. No vario, but still climbing good. The tension never dropped.

Then why would you be attempting to release?

It felt like it accelerated to weak link failure.

That WOULD explain the weak link failure.

It was real breezy that day. That might be a factor?

Assuming you're heading into the wind and the driver leaves the hydraulic pressure alone...

1. The tension your glider - and the truck - will be feeling will be constantly increasing as the line feeds off the reel and decreases its effective diameter.

2. You'll start climbing off the platform at about a 70 degree angle. Higher performance (L/D) gliders will climb at higher angles, lower at lower.

3. The tension you'll be feeling will also be constantly increasing as a consequence of line weight - which will work totally against you. It will be as if you're constantly taking on ballast, cause the line to pull off the winch faster and sag down, and pull less forward and more down - thus causing the glider to trim at a lower pitch attitude. The heavier the line the more the sag and the more gas the truck's gonna hafta burn to keep you climbing.

4. The drag of the line - which increases as a consequence of its diameter - will cause the line to bow back and pull off the winch faster and, as is the case with the weight and sag, also pull less forward and more down and also cause the glider to trim more nose down.

5. These two factors - weight and drag - will put you at a lower angle (farther) behind the truck and climbing less efficiently. At some point, even with unlimited runway and line, you're gonna be unable to climb any more.

6. With a headwind - call it 15 mph - your driver's gonna have his airspeed indicator reading exactly the same for launch and climb but his speedometer (groundspeed indicator) is always gonna be reading 15 mph slower.

7. Neither the winch, your glider, nor your weak link are gonna know the difference between no wind and fifteen before you get to the altitude you could on that runway in no wind.

8. But... With the headwind you will be using the runway more efficiently / effectively and reach your no wind max altitude with - let's call it - a third of the runway left over.

9. From that point on, because of ever decreasing reel diameter and ever increasing line length, weight, and drag, your glider and weak link are gonna be feeling ever increasing tension beyond "normal".

Not sure of their top-off procedures but Zack will probably say the pressure is increased at the end of the tow.

Let's not use the terms "pressure" and "tension" interchangeably. Drives me nuts.

TENSION is what the towline is transmitting and the glider is feeling and is expressed in POUNDS.

PRESSURE is what the hydraulic fluid is under, is read off the gauge as POUNDS PER SQUARE INCH, and - as long as the drum is turning - is directly proportional to tension. But there are a lot of variables you gotta plug into the equation to get a rough idea how that translates to tension.

Vehicle slows.

As long as the drum is turning the tension isn't gonna be changing appreciably in the short run (insignificant decrease in reel diameter and increase in line out). If the drum stops turning the tension is gonna drop as the vehicle slows.

I'm not sure if it is possible to over fly the tow vehicle while still climbing with tight line. That kinda sounds like perpetual motion.

1. Throw a thermal, dust devil, or strong gradient into the equation... Yes - You CAN achieve perpetual motion (for long enough anyway).

2. If you start out with enough airspeed you can also continue to climb with a tight line straight over the vehicle - but that's not gonna happen with much line out.

3. And of course you don't wanna fly very far in front of the vehicle with a tight line - climbing or not - 'cause you won't live very long if you do.

Where's Zack?

Haven't heard from him in a bit. That usually means he's on a loaded schedule.

The more experienced PL pros are probably laughing at my ignorance. When I become a pro...

I don't give a rat's a** about how EXPERIENCED any of the PROS - or any other folk - are. In hang gliding pros and experienced people are usually just really really good at doing things really really wrong - and are often just as ignorant and always at least as stupid as they were at the end of Day One. What impresses me is someone who understands the relevant principles. What satisfies me is someone who at least conducts operations consistent with the principles - even if he doesn't really understand them.

There isn't a whole lot in the fundamentals of hang gliding - launching, landing, towing - that benefits much from experience once a little muscle memory skill is developed. Spark just proved that bigtime in the Golden, Colorado LZ a couple of weekends ago.

...I hope I never get too important to talk to students with questions.

Or to assume that you can't learn something extremely valuable about some aspect of aviation from someone who's never been around it before and may have little to no aptitude for it.

And, by the same token, one thing you can rely on like death and taxes... If you're ever in a debate with someone who asks about your experience and/or skill level and/or brings up his - you KNOW you're talking to a total idiot who isn't worth the time of day. NEVER fails.

P.S. I'm not seeing a way to get the photo up - may be a problem with my antique browser. But Bob can probably stick it in later if I send it to him. And anyway, the topic IS "missing release".

Admin Note: Here's the "missing release" that Tad sent to me by email:

It looks like you guys are swapping information...

Swapping?

So far all I'M getting is a picture of glider end towing equipment which has evolved significantly backwards from what I was using twenty years ago.

So far all I'm doing is spending a lot of time and effort GIVING much better information than the "pros" controlling this sport are SELLING.

This I am perfectly happy to do. But I'd be a lot happier KNOWING that this information is getting through and causing things to move forward and, so far, I'm not getting an indication that that's happening.

...and no one is getting thrashed...

Ya actually need a lot of thrashings to keep the skies and highways safe. THE primary reason hang gliding stays so insanely dangerous is because nobody gets a well deserved thrashing unless it's from Mother Nature. And Mother Nature usually just thrashes undeserving victims of serial offenders like Steve Wendt. And Mother Nature doesn't always use much in the way of restraint or proportionality - the way a competent organization could.

...or insulted.

Oops. Getting behind my quota.

Davis and Jack are evil stupid cowardly douchebags.

Ya go with reason on the occasions in which it works but you need a good Plan B for the other ninety-nine percent of the time.

You guys are really disappointing Davis and SG.

Not until we effect positive changes.

But rather than give you a fish, how about if I give you a fishing lesson?

Build a man a fire and you keep him warm for a night. Set a man on fire and you keep him warm for the rest of his life.

Thanks, but the problem is my 2003 Mozilla 1.3.1 browser.

At the bottom of your posting page, there's a tabbed box that looks like this...

At the bottom of YOUR posting page - but, I'm afraid, not mine.

I don't see those tabs - just empty white space.

If I Select All, Copy, and Paste into word processing I DO get text that reads "Options" and "Upload attachment" but there's nothing visible or clickable on the browser page. If I click in the location where "Upload attachment" should be, nothing happens. I was pretty sure I'd have been OK firing up the other computer but I didn't feel like firing up the other computer just then.

I get this issue with a lot of stuff on the Hawks and Strings pages and often have a few hoops to jump through to get things done.

Thanks for the fishing lesson anyway, I'll send you the photo - just 71 K.

P.S. The tabs are visible/functional for me back on the main drag - just not here in South West Texas.

What was the material? How many strands/loops?

You can see it in the photos in the first post. Comparing the line diameter to the pin width my best guess is 205 leechline (single loop).

I usually get off the line hella quick at this point 'cuz I dislike high tension, but I would imagine you could gain a good bit of altitude staying on the line.

Stay on. There's nothing that can happen to you in those circumstances.

Not always, as described above.

Hadn't experienced or thought about that scenario.

Most guys don't want pressure to be backed off.

Jerry Forburger - 1990/10

High line tensions reduce the pilot's ability to control the glider and we all know that the killer "lockout" is caused by high towline tension.

Towing Aloft - 1998/01

Fortunately, we have good defenses against lockouts. These defenses include limiting the tow forces by using weak links and pressure gauges...

Three recent aerotowing accidents have occurred--one fatal. The common thread in all three was a lockout and the use of a much too heavy weak link.

A weak link is an integral part of any towing system in order to prevent overloading and lockouts.

Guess near the tops of the tows those guys start locking out like crazy, huh? Do people able to keep control of their gliders all the way up win special T-shirts?

I don't pay to much attention to winch issues 'cause I:

a) was always an aero junkie; and

b) think that the guys that operate them tend to be pretty good at it ('cause they hafta be 'cause the rigs are always breaking down and demanding that their owners be good mechanics, improvisers, and engineers).

But I was surprised to see Stu's skinny little levelwindless reel and a lightbulb lit upon reading his explanation. Yeah, the tension goes up pretty fast as you pay line out but that's pretty much what you want anyway.

No, but it can cause weak links to break.

Go ahead and blow them. It takes a lot of time, money, wear and tear, and gas to get to the top of a tow. And sometimes a few extra feet can mean the difference between an awesome day and a sled ride with no further shot at the soaring window. (And thanks again, Ridgely, for all those years of 260 pound loops of 130 Greenspot and all that prime time waiting for relaunches. (Idiots.) But I guess they helped a lot with downtube sales.)

(Even so, they are extremely rare in our group...I can't remember the last time we had one blow.)

How extraordinary. I can't remember the last time when fewer than a dozen didn't. In 2008 Bob Buchanan managed ten consecutive all by himself ('cause he wasn't flying SMOOTHLY enough).

What are people using for launch tensions?

Line drag does not affect tension, correct? This is something we've (HHPA) debated in the past.

Shouldn't be debating. All this stuff can be thunk through. It ain't easy and it always takes me forever to redo it every time the issue comes up but do sketches, vector diagrams, extreme scenarios, thought modeling.

Aerotowing...

The planes are level and the line is horizontal with a tiny bit of sag and aligned well with the airflow so drag a negligible issue.

1. Both planes are supporting EXACTLY the same line weight.

2. The tug is dealing with ALL of the line drag, the glider is dealing with none of it, so the front end weak link is feeling a wee bit more pain than the back end one.

Static...

1. When the glider first becomes airborne it's an aerotow - same weight supported at both ends, truck dealing with all of the line drag.

2. As the glider climbs it starts taking more of the weight.

3. Line drag increases because it shows progressively more profile, the truck has to use more gas to compensate and maintain airspeed, and the towline bows and reduces the forward vector getting to the glider.

3. When the glider climbs straight over the truck (which it can't unless its glide ratio is better than a hundred to zero) and the towline is straight vertical (which it can't be if its diameter is greater than zero millimeters) it's supporting ALL of the line weight and the truck is doing none of it.

4. If we make the line diameter greater than zero millimeters and make the glide ratio a hundred to negative twenty (or cheat and use a Mosquito harness) so the glider can stay straight over the truck while dealing with a towline that's being bowed downwind of the vertical line... the truck and glider are sharing extra tension due to line drag equally.

Platform...

Ignore tension variations due to spool rpms, inertia, and ever decreasing diameter and assume the reel is always turning.

01. The line at the point it's coming off the drum is ALWAYS feeling (call it) 150 pounds.

02. Line (and/or glider) drag can NEVER have an effect on that 150. When it tries (which it always does) all that happens is that pulls line off faster.

03. Make the line weightless to get all that mess out of the equation.

04. The line at the glider has always gotta be coming into it at some measure of forward angle or you're not climbing and already got off a while back.

05. Instead of thinking line drag think tiny parachutes on the line every twenty feet along the five thousand feet that's out.

06. The line tension measured between the winch and the first parachute is 150 pounds.

07. The line tension measured between the first and second parachute is a little less than 150.

08. The tension reaching the glider (and its weak link) is 150 pounds minus what's eaten up by those 250 parachutes.

09. So the line drag DOES affect tension but - with respect to the glider (which is a big terminal lift and drag generating parachute) - negatively.

10. But let's give the line its weight back.

11. So as the tow progresses we're getting more line out, more drag, more sag and bowing, and more weight to offset the tension reduction at the top/downwind end of the towline.

12. Because of sag and bowing - near the glider the line will be showing more profile to the wind and the parachutes will be bigger or more closely spaced but my head hurts way too much already.

I just checked Wings & Wheels and they give the weight of a thousand feet of two thousand pound Spectra as only 3.3 pounds so it appears that virtually all of that weak link endangering tension you're feeling when the truck's approaching the end of the runway is winch.

I'm sure you have a good reason for not upgrading...

I'm upgraded as far as I can go on this old OS 9 capable machine which I've got tricked out for word processing and lotsa other stuff I wanna do. I can play it like a piano. I'm screwed when I wanna browse so for lotsa stuff I've gotta fire up the new machine.