It's not a sleeping dog, asshole. It's a constant hyperactive lethal threat.
...has been hashed out on other forums akin to whipping a dead horse.
Yeah, that "whipping a dead horse" line is a perennial favorite with the shitheads on the majority/established sides of indefensible positions.
Some moderators have even lock down threads about weak-links rather than go stark raving mad.
Oh. SOME moderators have EVEN locked down threads about weak links rather than getting there balls ripped off and handed to them whenever sanity starts rearing its ugly head.
- Moderators are - by definition - SCUM. They're insidious enemies of the First Amendment freedoms that all those guys who got slaughtered on Omaha Beach were supposed to have been giving their lives for and absolute murder on minority positions.
- Yeah. I've been permanently banned from seven separate hang gliding forums (counting CHGA from which I got a permanent three month suspension near the end of 2008) and one (the) paragliding forum - not to mention permanent banning from hang gliding itself - for winning battles against you goddam pigfuckers on this issue. Whenever you go into Bible Belt country saying Creationists are totally full of shit you're not gonna make a lot of friends.
Forget the endless argument over what weak-links are for.
There is no argument over what they're for.
Tost Flugzeuggerätebau
Weak links protect your aircraft against overloading.
Anything beyond or other than that is just pigfuckers pulling opinions outta their asses.
Simplify it down to what they do.
Tow--or--break.
Yes. And WHEN they break - either because they're dangerously and usually illegally light or because a tow has been allowed to get dangerously out of control - the aftermath is almost always some degree of ugly.
Forget what releases are for.
Simplify it down to what they do.
Release--or--fail to release.
BULLSHIT. If it doesn't release it's not a release. It's just an attachment point for a towline or bridle end. Reasons for it not releasing:
- It's a bent pin piece of shit that wasn't designed for towing anything.
- The actuator is located within easy reach on an aircraft which requires two hands to fly.
- All of the above.
And it's a real safe bet that you've never once in your entire flying career flown with an ACTUAL release on your glider so you should probably shut the fuck up on that issue.
First this: Tow--or--break.
If a weak-link breaks and it puts you at risk due to loss of towing tension what was your plan B, for when the towline failed?
I dunno, Bill. If you lose your engines just as you lift off from the runway at BWI what's your Plan B? Head between your legs and kiss your ass goodbye?
How 'bout right after launch at Dry Canyon with a hundred and fifty feet of air under you and your sidewire fails?
Now cite an incident in which engines were lost on takeoff, a sidewire blew at 150 feet, or a towline blew in which the issue couldn't be traced back to an incompetent and/or negligent douchebag.
For when the release broke apart?
I don't fly with a release that can break apart. And little makes me happier than the benefit to the gene pool you get when somebody gets killed because his release broke apart.
For when something went through the aero-tugs prop and it disintegrated?
Like when the plastic gas tank went through Jon Leak's Cosmos prop and ended my first aerotow clinic after one flight?
- Maybe it's a good idea to design aircraft such that stuff doesn't come loose and go through the prop.
- Trike was outta commission but there was never the least problem with the glider. So what's your fuckin' point?
For when the tow vehicle ran out of gas?
What's the tow vehicle? A tug, truck, snowmobile, boat?
- How much of a problem does that tend to be for the glider when the engine sputters to a stop and the vehicle starts coasting?
- Does anybody really wanna be towing with people too stupid to have enough gas in the tank to complete a tow?
For when an internal muffler baffle broke off inside and plugged the aero-tows muffler exhaust, killing the motor? (Hopefully nothing else.)
Fuck you, Bill.
For when the tug's throttle cable broke?
Prop's still spinning, right? Doesn't sound all that traumatic to me - or am I missing something?
For when the oil injector failed and the motor seized?
Tug's...
...toast. Glider's fine. So not my problem and who gives a fuck.
For when the tug pilot bumped the choke lever and flooded the motor? For when a deer or kid ran out in front of the platform truck? For when dirt got into the fuel and killed the motor? For when the spark plug fouled?
HAD ENOUGH?
No, keep going with this bullshit. You haven't said anything about rattlesnakes or Al Qaeda terrorists yet.
No? Okay then -- to continue, what was plan B, for when the tugs joystick control cable broke on the tug?
Release, land, toast marshmallows over the flaming wreckage? (Using earplugs, of course, to protect your hearing from the agonized screams of the roasting former Pilot In Command of your glider.)
For when the tug couldn't clear the trees and dumped the towline?
You mean like when Dave Farkas was heading for the trees and trying to use his piece of shit trike release to dump Bill Bennett and Mike Del Signore into a fatal tip stall before his piece of shit front end weak link did the job for him?
For when the tow trucks coil burned out? For when a tow vehicle tire blew out? For when the tugs front wheel fork snapped and dug into the dirt before lift off?
As opposed to snapping and digging into the dirt AFTER liftoff? Yeah, I watched a douchebag's Dragonfly do that one time. One of my fonder memories from this sport.
OH ---OH--
Here is one you'll like: A friend had his chest safety belt come unhooked from the lap buckle and the chest belt went into the prop killed the Rotax engine and destroyed the prop.
How 'bout the glider? Was he able to exercise the extraordinary skills he needed to handle that one?
I know other motor heads out there are reading this and haven't yet read here what happened to them. Feel free to reply and expand the list of other stuff that can reduce thrust that wasn't planned.
Here ya go...
Bill Bryden - 1999/06
During the tug's roll-out for the second launch attempt, the tug pilot observed the glider clear the runway dust and then begin a left bank with no immediate correction. At that point he noticed that the launch cart was hanging below the glider and immediately released his end of the 240 foot towline. The tug never left the ground and tug pilot watched the glider continue a hard bank to the left achieving an altitude of approximately 25 feet. Impact was on the left wing and then the nose of the glider. Rob was killed immediately from severe neck and head trauma.
Tug pilot makes a good decision in the interest of your safety / fixes whatever was going on back there by giving you the rope while you were working on getting your glider straightened up and in position to deal with a problem.
No. YOUR idiot fucking point you're trying to present as THE point to support your idiot fucking position.
...is if you are being towed into the air and not expecting that at any second you will be able to handle the loss of tow tension, YOU ARE DOING SOMETHING WRONG!
BULLSHIT.
- You go into the air with the best equipment you can get your hands on or develop yourself (and you won't get it from anywhere inside the Industry 'cause they've all collaborated to make sure that nobody provides anything that isn't total shit) and fly in a manner such that you'll be best able to respond react to any dangerous micrometeorological events or equipment or operator issues.
- If you EXPECT to be able to HANDLE any event or combination of events that gets thrown at you then you are a total moron.
I'm CERTAIN that I can equip myself to be able to safely handle the shit that Mother Nature threw at Zack Marzec. And I'm also CERTAIN that some asshole on the other end of the string with a Dragonfly tow mast breakaway protector and a few fingers on the release lever ready to make a good decision in the interest of my safety can kill me just as dead as Zack Marzec and there won't be a goddam thing I'll be able to do about it.
flying two point. Yeah, he could/should've been holding the nose down better. But have him doing that, hit him with a real blast of lift, and tell me that he'd have definitely been able to walk away smelling like a rose. The blast he'd have definitely been able to handle. The blast PLUS the Hewett Link...
You give us all this bullshit that's happened ONCE in the course of some asshole's flying career virtually always as a consequence of negligence and/or incompetence and, for all intents and purposes, NEVER happens in real life towing operations and ESPECIALLY NEVER HAPPENS at critical points in real life tows - low altitude when other critical shit is going on.
And BECAUSE all this dangerous stupid shit has happened somewhere sometime that makes it OK to MANDATE that for EVERYONE who goes up on Davis Links which GUARANTEE *INSTANTANEOUS* loss of 225 pounds of thrust on up to six out of six consecutive NORMAL FLIGHTS in DEAD AIR.
What an INCREDIBLE ASSHOLE.
Example. The contest launch director signaled the tug to start the tow.
Fuck the goddam contest launch director. When the tow starts is ONE HUNDRED PERCENT the call of the glider - the guy who's PAID FOR the tow. And NOBODY disputes that. And if we're supposed to swallow Jim Keen-Intellect Rooney's bullshit about there being one Pilot In Command for the duration of the tow that issue should tell us that the Pilot In Command is the guy it SHOULD be - the one whose life is most being endangered and who's in the position which requires the better judgment, equipment, and skills.
There is a two to three mile per hour tail wind. You're comfortable that your weak-link will not break because you are using a strong-weak-link.
Define those terms in *Gs* - motherfucker.
The (Lord help me--)...
The Lord's about all you have going for you, Bill.
...strong weak-link will get you safely to altitude so that you would have enough room to turn into the wind to land should it become necessary.
How does it EVER become necessary to turn into a wind that's blowing two and gusting to three?
The last thing you want to do is give up your, "next up," position and go the back of the line with your launch dolly to eliminate the tailwind launch.
Ya got that goddam right, Bill. But don't worry, if you're flying under Flight Park Mafia rules and show up at the front of the line with a stronglink consisting loop of 135 pound Greenspot you WILL be going to the back of the line to swap it out with a proper safe one.
But let's be real here.
No Bill. Stick with your lunatic Hewett inspired delusions. So much more fun that way.
Will the stronger weak-link also protect you from all those other thrust killing events that we just went over and others that we haven't even brought up?
I'll take my chances with them pigfucker. You don't hear about tuggies having six engine failures in a row because they don't like it when THEY get all THEIR thrust killed in a millisecond and they tend not to be able to handle the inconvenience quite as effortlessly as they're always telling us muppets we should be able to.
It is times like these that you have to recognize that, YOU ARE DOING SOMETHING WRONG! (Pop Quiz. In this case what was it?)
Fuck you, Bill.
Our best flying happens in zilch wind thermal conditions when the thermals are commonly sucking in any direction you wanna name. There is NOTHING WRONG with flying a six hundred pound weak link in switchy air behind a competent tug pilot. The chances of a thrust failure prior to getting to an altitude at which you can pick any direction you want are zilch and nobody ever got scratched 'cause he came in with a five mile an hour tailwind at a goddam AIRPORT.
Does the thought of your weak-link breaking make you uncomfortable?
GODDAM RIGHT. I put up with that crap my entire AT career and it scares me SHITLESS. That and some douchebag on the front end ready to make a good decision in the interest of my safety are the ONLY things I'm scared of on an aerotow.
It shouldn't.
Yeah, we've been listening to assholes like you constantly telling that for decades. Also bending over backwards to tell us what fuckin' muppets all the people who've been smashed up by this lunacy are/were. But THIS:
Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974
"The greatest dangers are a rope break or a premature release." - Richard Johnson
When I/we static tow (ST) with a car or truck we use 1,600' of towline.
When you/you static tow you're throwing away the massive safety margin provided by a constant tension / payout winch - a safety margin which would've allowed Deb Young to complete her flight smelling like a rose so please shut the fuck up about the goddam weak link.
We tow not to the end of the tow road but 3/10 of a mile short of the end. After we dropped the line the car will slowly drive to the end. That will allow our dropped end to be pulled out of the side field and back up onto the road. All this while the weak-link would be getting roughed up for 3/10 of a mile.
Did you ever consider:
- leaving the weak link with the glider so's there's no dragging involved?
- using a Tost weak link assembly in which the inserts are totally protected from wear?
Just kidding.
We would release the car end and go back to attach to the pilots' end and pull it back to the next pilot. So we would never reuse a weak-link.
Great approach, Bill. I've designed weak links which never need to be replaced.
Since it was a one time use we often would troll down the tow road for thermals. If we were approaching the 3/10th of a mile end point and before we got there and having not yet hooked a thermal we would, "Milk the weak-link." We would see how much extra altitude we could get before the weak-link broke or we arrived at the 3/10 of a mile end point.
Why should an element of the towing system whose sole function is to protect against overload ever break under circumstances such as those?
The strongest weak-link that we ever used was 350 lbs. (1.6 times our all up weight.) for payout winch/reel.
Why?
For static we use 220 lbs for a weak-link.
Why?
Neither of these two breaking limits would cause any control problems when they broke. (Of course you have to pull the bar in when the weak-link broke or the hang glider will climb, drop airspeed and stall.)
Well that's great then, Bill! That proves that at a thousand feet with the glider completely under control - if, of course, one pulls the bar in when the weak link breaks - it's physically impossible for anyone using either of these strengths or anything in between to ever have a problem. And, of course, we can extrapolate to show that for anyone using either of these strengths or anything in between it's physically impossible to have any kind of problem under any circumstances - if, of course, he pulls the bar in when the weak link breaks.
So now we also know that when Jim Keen-Intellect Rooney tells us that he and his pigfucker buddies know what they're doing we're getting solid information.
Nothing takes all the fear out of a weak-link breaking than doing it on purpose during the many static tows that you do.
I REALLY like that, Bill. Reminds me a lot of the Aussie Method. If you never get into your harness unless it's connected to your glider all the fear of launching unhooked...
Each of us agrees that it is not a particular method, but rather the fear of launching unhooked that makes us diligent to be sure we are hooked in every time before starting the launch run.
Beyond these facts anything else would be pure speculation. I have personally had numerous weak link breaks on tow, both low and high, after hitting turbulence and have never felt in danger of a tumble. I have witnessed countless others have weak link breaks with no serious problems. We train aero tow pilots how to handle this situation and I am certain that Zach had also encountered this situation many times before and knew how to react properly.
...had TONS of practice breaking Rooney Links so we know that fear of such events CERTAINLY wasn't a factor in his fatal tumble at Quest early last year.
I think we should use even LIGHTER weak links so's more people will experience more pops in more circumstances, find out how little they should be feared, and stop whipping this dead horse and forcing our moderators to lock down threads to save themselves from being driven stark raving mad.
You develop a feel for when they are about to break.
Yeah, just like the people who used to argue with Donnell - who's well respected for his knowledge of towing, bridles, and weak links - always said...
Donnell Hewett - 1980/12
Now I've heard the argument that "Weak links always break at the worst possible time, when the glider is climbing hard in a near stall situation."
At the worst possible time, when the glider is climbing hard in a near stall situation.
It even helps when towing into a thermal low. You know when to get the nose down to save your weak-link so that you can continue to top out.
Release--or fail to release.
I can't agree with the following statement that I have heard from several sources in the past that goes something like this--
The statement:
I no more expect my release to fail than I do my hang strap.
GOOD. It makes me nervous when total morons start agreeing with rational statements.
I don't think releases are as reliable as a hang strap for the following reasons.
They're not. Just beyond the scope of human engineering to get one that works much more than about sixty percent of the time. And when you try you just get homemade Rube Goldberg funky shit that Jim Keen-Intellect Rooney won't tow because it doesn't work because if it did everybody would be using it already.
The minute someone starts telling me about their "perfect"system, I start walking away.
The minute someone starts telling me about his "perfect" system I just start walking away. And it's pretty fucking obvious that you do too.
I've used just about every release known to the sport of hang gliding...
You oughta try some of the ones that the sport of hang gliding doesn't want you to know about.
...with the exception of the chest mounted KOCH...
Which - surprise surprise surprise - is the most effective surface tow release in popular use in both hang and para gliding.
...and a Tost release.
Which is a built in sailplane release pretty much totally incompatible with hang glider towing.
I've noticed that even this Tost release had several theories involved for the failure with similar applications that are recorded at the sailplane website.
Bullshit. That thing's bulletproof and fuckin' amazing.
It is quite possible that the hang gliding use and the sailplane use have nothing at all in common.
With respect to the Tost release, for all intents and purposes, they don't.
I have no experience with any type of chest mounted KOCH or Tost release.
Oh wow. You can misuse and abuse aviation equipment and get it to not work. Who'da thunk? You need to spend more time with your buddy Jim Keen-Intellect Rooney - once he gets over his love for Joe, of course.
Why aren't straight pins used?
That's easy. They can't be used with anything but thin lines.
They also can't be made with anything but thin lines.
Tad loves to forget that I've actually gotten one of his to jam.
NOTHING is perfect kids.
Straight pin releases can work, but they're not the panacea that these guys are claiming.
One of his favorite hobbies is finding stupid stuff you can do to carefully engineered tow equipment to make it not work to a degree that his Industry Standard shit doesn't work when you use it in accordance with the fuckin' manual.
What's it say about the purposes of the weak link over there, Bill? And what's it say about using weak links which have degraded below the manufacturer's specified rating?
This is not going to be an in depth investigation into the reasons that all releases that I have used to date have failed.
Did you ever think of using releases that people have developed that DON'T fail? Just kidding.
If I believed for one second that my hang strap was equally as reliable as the best release out there I would not fly again.
Yeah. You're using crap for releases - like Peter Birren's Eighth Wonder of the world that can't be blown in anything remotely resembling an emergency and can be knocked out of action by a looped lanyard or a little wheat stubble in the slot.
What I do is adopt a procedure that has, built into it, allowances for the few chances of a release failure.
Yeah Bill. And what *I* do is engineer releases that eliminate all failure possibilities. 'Cause *I* understand that when the shit really hits the fan you're gonna be lucky to be able to execute Plan A in the one second window you'll have available.
Why? Because I've had a few too many release failures.
Try not using stupid junk. Of all the release failures you've had and know about how many of them weren't totally and easily predictable? I know of ZERO examples myself - including the embarrassing incident with my own Four-String design (which, consequently, is now a Three-String design).
On the other hand if my hang strap had failed with the same regularity as my release failures you would not be reading this.
And what a tragic loss that would've been.
I was really excited years back to read up on the Link-Knife development and ordered several.
The facts that you were able to read about in Hang Gliding magazine and that Peter got a USHGA Safety Award for it should've set off all kinds of alarm bells.
Imagine if you will, just coming off the cart and center punching a thermal which takes you instantly straight up while the tug is still on the ground. Know what happens? VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8 G). So you pull whatever release you have but the one hand still on the basetube isn't enough to hold the nose down and you pop up and over into an unplanned semi-loop. Been there, done that... at maybe 200 feet agl.
Right.
(Or at least to those less of one than me.)
The first failure was when the release after having been dragged through the snow, which filled up the plastic tube, then froze solid at altitude. Pulling the release cord just shook and bowed the towline a little.
Here's a thought, Bill... Don't drag critical flight equipment through the snow. I'm guessing SR-71 pilots don't drag their pitot tubes through the snow and expect them to work climbing through twenty thousand feet.
The second failure was slushy snow on the "O" ring.
Not a real quick learner, are you?
At altitude it froze to the plastic tube and prevented the "O" ring from moving which prevented the weak-link string from coming in contact with the two internal razor blades.
Yeah. Now that I think about it NASA had a problem with an "O" ring designed to seal sections of a solid rocket booster for launches in Florida when they decided to take a chance on sending it up in sub freezing temperatures.
Pulling the release cord just shook and bowed the towline a little.
Try wheat stubble next time and see how that works.
The third failure (not the fault of the release) was using some twisted poly-pro towline instead of diamond braid poly-pro 3/16 inch.
Don't use polypro - asshole.
Under tension the rope untwisted about three to five times which wrapped the Skyting Bridle...
Don't use a Skyting Bridle - asshole.
...up about three to five times and captured the release cord between the keel rope and the body ropes to the pilot. Pulling the release cord just shook and bowed the towline a little.
Gettin' good at that, aren't ya?
The fourth failure was during mid summer on what we referred to as Gene's Field. Gene Stone found it. A piece of straw somehow got into the slot of the Link-knife and shielded the weak-link string from the two razor blades.
See? Told ya so.
Pulling the release cord just shook and bowed the towline a little.
Four failures so far, three of them on the Link Knife in three separate flavors. The greatest contribution to hang glider towing since they took the lower attachment off the control bar and put it on the pilot. The only release that USHGA has reported on and endorsed in modern history. Go figure. (Did I mention that Peter banned me from his show two years ago for telling him to go fuck himself when he told me that I was only allowed to say stuff which supported his opinions?)
I've had threaded bridles capture in the process of unthreading after releasing.
I've designed threaded bridles that are highly resistant to totally incapable of wrapping.
I've had straight pin barrel releases fail to release.
Yeah, ones you've packed full of slush before flying them to altitude.
I've had curved pin barrel releases fail to release.
- Who hasn't?
- Why would you even bother going up with bent pin shit like that?
Which by the way I hope everyone has seen the picture that Jim Rooney put up on the OZ report about accidentally rigging up a curved pin barrel release backwards so that it will not release once the barrel is pulled back.
I hope they haven't. I'd SO love to get another kill out of that crap - one not just 'cause...
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.
...some asshole had no chance to get to it as he unbelievably stupidly always thought he could.
Did anybody look at MY pictures, illustrating for the benefit of the third grade science challenged, why that moronic bent pin piece of shit would jam when deliberately "properly" rigged...
...and predicting years in advance idiot fucking Bart Weghorst's failure?
I find it unbelievable that this failure to release didn't also happen to me.
Me too. And that's why you need to understand that you really don't have any fuckin' business commenting on releases and weak links. You need to understand that you need to leave that kinda job to people who understand basic engineering and flight dynamics.
I must be getting luckier.
Yeah, assholes like you damn near always are. And whenever you luck out with some bullshit like a weak link light enough to get blown by a driver stomping on the gas you see the light and start spewing out the wisdom gained from your experience all over the sport to the joy of all the other luck based idiots.
I'll spare you the other release failures and captures.
Thanks. No need to publicize all the fatalities waiting to happen that are in circulation over a good chunk of the planet. The goal here is to show people that there's never any need to be afraid of weak link pops and encourage everybody to use the lightest ones they can use to get to altitude in sled conditions.
I'm able to post this because I never towed with a weak-link --- that wasn't!!
Yeah.
- 1.6 Gs was totally fine because you could always use it as an instant hands free release whenever you wanted to and just fly away.
- If you'd JUST ONCE flown with a STRONGLINK you'd have been killed instantly.
I'm not going to waste my time worrying about a weak-link that might break.
Good.
I'll save the worry for when it doesn't.
You've never been in an emergency situation with a release filled with frozen slush and being left dependent upon a weak link as a backup. The assholes who've counted on that strategy are pretty much all dead. Whenever everything is smooth, level, high, climbing, normal there's all kinds of stupid shit you can get away with. Classic examples:
Try reading some ACTUAL serious crash and fatality reports and see just how much validity this dangerous bullshit you're spewing has. If this crappy sport had any integrity to it you'd have your ratings suspended for making statements like this. This is totally analogous to the Andrew Wakefield autism/vaccines bullshit and that motherfucker lost his license.
And you're just an echo chamber for Donnell and his delusional crap and he's THE most successful serial killer in the history of sport aviation.
If you are of the opinion that the weak-link is only there to protect the hang glider...
That's not an OPINION - asshole. That's the only legitimate function of the weak link and the only one that can be proven to work using ACTUAL NUMBERS.
...and you are using a tow line with the same strength as 3/16 poly rope then why not eliminate the weak-link completely? 3/16 poly towline will never break a hang glider in the air.
CFR > Title 14 > Chapter I > Subchapter F > Part 91 > Subpart D > Section 91.309
§ 91.309 Towing: Gliders and unpowered ultralight vehicles.
(a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless-
- (3) The towline used has breaking strength not less than 80 percent of the maximum certificated operating weight of the glider or unpowered ultralight vehicle and not more than twice this operating weight. However, the towline used may have a breaking strength more than twice the maximum certificated operating weight of the glider or unpowered ultralight vehicle if-
-- (i) A safety link is installed at the point of attachment of the towline to the glider or unpowered ultralight vehicle with a breaking strength not less than 80 percent of the maximum certificated operating weight of the glider or unpowered ultralight vehicle and not greater than twice this operating weight;
-- (ii) A safety link is installed at the point of attachment of the towline to the towing aircraft with a breaking strength greater, but not more than 25 percent greater, than that of the safety link at the towed glider or unpowered ultralight vehicle end of the towline and not greater than twice the maximum certificated operating weight of the glider or unpowered ultralight vehicle;
Some pilots may think this last suggestion about removing the weak-link sounds stupid but that's only because they're correct.
It IS stupid. Permitting sailplanes and hang gliders to fly at half a G under manufacturer specifications is also stupid - and a helluva lot more dangerous. I want to know EXACTLY what my breaking strengths are so's I can push the load all the way up to the most I wanna stress my release system and I can't do that with a goddam rope that's getting baked in the sun and dragged across the ground all the time.
If you haven't hooked up your towing bridle and weak-link between two vehicles (car or truck) and slowly pulled the weak-link to destruction to see what will happen ---YOU ARE DOING SOMETHING WRONG!
BULLSHIT.
The United States Hang Gliding and Paragliding Association, Inc. - 2013/01/23
12. Standard Operating Procedure
10. Towing/Aerotowing Administration
09. Aerotow Pilot Appointment (ATP)
-B. Aerotow Equipment Guidelines
03. 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.
04. A weak link must be placed at both ends of the tow line. The weak link at the glider end must have a breaking strength that will break before the towline tension exceeds twice the weight of the hang glider pilot and glider combination. The weak link at the tow plane end of the towline should break with a towline tension approximately 100 lbs. greater than the glider end. Weak links must be used in accordance with 12 CFR 91.309(a)(3). The USHPA recommends that a nominal 1G (combined operating weight of the glider and pilot) weak link be used, when placed at one end of a hang glider pilot's V-bridle; or about 1.5-2G if placed at the apex of the tow bridle or directly in-line with the tow rope. The actual strength of the weak link used by the hang glider pilot must be appropriate for the operation and have a breaking strength between 80% and 200% MCOW (max. cert. operating weight) of the glider, in terms of direct towline tension. The weak link used at the tow plane end of the towline must be stronger, but not more than 25% stronger, than the strength of the weak link used at the glider end of the towline.
05. A release must be placed at the hang glider end of the tow line within easy reach of the pilot. This release shall be operational with zero tow line force up to twice the rated breaking strength of the weak link.
We know that all commercial aerotow operations are using:
- FAA legal weak links for solo AND TANDEM at the USHGA recommended one and a half to two Gs
- releases that can handle three to four Gs - in compliance with USGHA requirements - on tandem gliders
So put ANY of these same releases on a SOLO glider... No brainer, dude. I mean, if you can't trust USHGA, flight parks that have been perfecting aerotowing for twenty years, Wills Wing dealerships... who CAN ya trust?
If a tow pilot hasn't had a release failure or a capture upon releasing -- you will.
Yeah Bill. You've used my equipment - or at least taken a serious look at the engineering, specs, performance test data - and you can make that prediction. Go fuck yourself.
There is a far, far, lesser chance of a hang strap failure.
There's zero chance of EITHER - motherfucker. I don't roll dice in the air.
Earlier you read that you should have a plan "B" for when you lost tow tension since there are many more possible causes than a weak-link break.
Yeah, you could have a SAFETY link break. WAY more dangerous than a WEAK link break. Or, worst of all, some egomaniacal shithead in a Dragonfly fixing whatever's going on back there by giving you the rope.
(Again motor heads please feel free to reply to this post with other thrust killing experiences not yet covered that you heard or know about.)
Fuck you, Bill. When we've got six consecutive Davis Links in a row increasing the safety of the towing operation in light morning conditions and the owner of the flight park which spent twenty years perfecting aerotowing telling everybody to double the perfected Davis Link with the huge track record we need look no further for thrust killing experiences. For every Dragonfly that runs out of gas with a glider behind it there are about ten thousand precision fishing line incidents.
Now what is the plan, "B" for a release failure, for example, while aero-towing?
01-001
04-200
07-300
10-307
15-413
Wait to slam in and break you're fuckin' neck? Oh, right... You're gonna be at a couple thousand feet over a dry lakebed on a platform tow and have the rest of the afternoon to hack yourself free with a hook knife.
Jim Rooney over on the OZ Report weak-link thread said something to the effect that a pilot could push out and pop the weak-link to get free of tow. (Paraphrased and not verbatim.)
As for being in a situation where you can't or don't want to let go, Ryan's got the right idea. They're called "weak" links for a reason. Overload that puppy and you bet your ass it's going to break.
You can tell me till you're blue in the face about situations where it theoretically won't let go or you can drone on and on about how "weaklinks only protect the glider" (which is BS btw)... and I can tell ya... I could give a crap, cuz just pitch out abruptly and that little piece of string doesn't have a chance in hell. Take your theory and shove it... I'm saving my a$$.
Jim and I are on the same page with respect to weak-links.
Doesn't seem to be a whole lot of gray area with respect to hang gliding people. Either intelligence and decency or brain dead scum. And the ratio's about a thousand to one.
My personal plan, "B" for when my release fails will be of no use to the pilots found in the camp of, "Strong Weak-Links. (oxymoron.)
Yeah, that was Mike Haas's personal Plan B. Got him off tow just fine.
Pilots in this camp are precluded from applying my plan, "B" so we have to move quickly to plan, "C."
The problem here is that I have never personally had to move beyond my plan, "B," to my plan, "C," Parachute (four feet off of the dolly?---yeah r-r-r-i-i-ght.) "D," Prayer, and last on the list, --- hook knife. (With the exception of one point attachment while platform towing which may work.)
101-20014
(I have at times had several redundant back up releases.)
And every time you don't need to use one you can get a credit for the time allotted for its use and bank it for use in a future flight.
I fully expect that cutting a towing bridle or towline (static tow, platform or dolly tow) near the ground would pose the ultimate test exercise for any "Focused Pilot."
I'd go with climbing back into the control frame after an unhooked launch.
My plan "B" after a failed release attempt is first to break the weak-link on purpose.
Yeah, your parachute isn't gonna work four feet off the dolly but your Rooney Link will.
And aren't you just so upbeat and positive about everyone and everything posted within your nasty little dictatorship!!!
I like the comparison between a release and a hang strap. That really drives h ome the point.
Which is what?
- Mike's point that he has as much dependence on and confidence in his release as in his hang strap?
or
- Bill's point that it's beyond the scope of human engineering to be able to design and produce a release that works more than sixty percent of the time and thus we should all stack our decks with fishing line that always breaks at the worst possible time, when the glider is climbing hard in a near stall situation?
Oh. You don't say. That way assholes with total mush for brains taking polar opposite positions will derive comfort from assuming that they've got a fair amount of support from you. As in:
I voted for Bob after spending a very enjoyable hour on the telephone with him a few months ago. My impression of Bob is that he is a level headed and enthusiastic supporter of both hang gliding and paragliding, and above all: SAFETY.
As forum moderator...
And what was it I said two hours, twenty minutes, and twenty-seven seconds before you identified yourself as "forum moderator"?
What will keep the US Hawks from becoming another USHPA or HGAA?
You will ... hopefully. The price of freedom is eternal vigilance. Everyone has to do their part once in a while. If you see something that's not being done correctly, then it's your duty to speak out. One big difference between the US Hawks and other organizations is that the US Hawks really does honor the free speech of its members.
Please explain to me how that despicable lie you paste up as a foundation of your phony little organization has the slightest meaning or value with a MODERATOR in unchecked control.
Does the US Constitution have a provision for a Moderator of free speech?
How 'bout a science classroom? Does the teacher/professor have somebody who presents the ideas that the middle ground finds acceptable and agrees upon?
I have "Moderator" status over here but I don't think or act as a moderator. It's aviation and there are right and wrong answers and I never have and never will moderate shit.
I try to read every post on the forum.
You TRY? How DO you manage to keep up with the workload?
I know Tad has long pushed the "strong weak link" idea...
Suck my dick, Bob. Tad has long pushed the "weak link a bit up from the middle of the legal range" idea which is totally in line with the crap Dr. Trisa Tilletti shoved into the SOPs and pretends everybody's in line with by tying loops of 130 pound Greenspot in special ways to get them to break consistently.
...and I'm glad to see the other side of the argument being presented.
I thought you were supposed to be this brilliant aeronautical engineer dude who has no respect whatsoever with vegetables such as myself who can't run Navier-Stokes equations in their sleep. And now you're GLAD to see the OTHER side of the "ARGUMENT" being PRESENTED by some deranged Rooney harmonizing Hewett cult member who takes pride...
If you take this away that angle goes from there to now there and the... You're stalled. You're stalled.
You know... You're plowing through the air.
And no longer can you...
So you immediately... When you lose this force you have to adjust the angle of attack, gain speed down...
They ARE fucking stalls.
...so we understand how to handle them and to not be afraid of them.
Yeah, "WE" (meaning anybody but YOU) understand how to handle them and to not be afraid of them.
The United States Hang Gliding and Paragliding Association, Inc. - 2014/03/14
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
11. Hang Gliding Special Skill Endorsements
-A. Special Skills attainable by Novice
-D. Aerotow
05. Must demonstrate the ability to control the glider position within the "cone of safety" behind the aerotow vehicle by performing "cross" and "diamond" maneuvers during tow at altitude with a tandem rated pilot who is experienced and proficient at performing those maneuvers. (Note: This checks for positive control and lockout prevention skills, somewhat like the "boxing the wake" maneuver used for sailplane aerotow check flights, but "boxing the wake" must not be performed by hang gliders on tow due to lack of 3-axis control.) The candidate must also demonstrate the ability to properly react to a weak link/tow rope break simulation with a tandem rated pilot, initiated by the tandem pilot at altitude, but at a lower than normal release altitude. Such demonstrations should be made in smooth air.
"WE" do them from dead center in the Cone of Safety on a glider being pulled two point and straight level at a couple thousand feet in smooth air at a point a tandem aerotow instructor decides won't cause any real problems.
...I had a terrifying stall experience with my instructor when I was learning to fly airplanes back in the 70s.
Fuck you. You're no more a pilot than you are an aeronautical engineer.
For a long time I feared getting close to stall. As long as I feared stalls, I was not spending much time getting comfortable with them, and that didn't make me a better pilot.
Fuck you. See above. You're almost as sorry an excuse as a pilot than you are a human being.
So there's a lot to be said for safely learning to handle the inevitable rather than trying to come up with some way to avoid the inevitable.
I once locked out on an early laminarST aerotowing. went past vertical and past 45 degrees to the line of pull-- and the load forces were increasing dramatically. The weaklink blew and the glider stalled--needed every bit of the 250 ft agl to speed up and pull out. I'm alive because I didn't use a stronger one.
Learn to safely handle your inevitable Rooney Link induced stalls in strong thermal conditions using actual Rooney Links at a hundred feet - MOTHERFUCKER. And make sure you have a camera running. It may not survive the impact but we'll probably be able to get something we can all treasure from the card.
Nice job Bill !!!!
Nice job moderating !!!! Motherfucker.
What was it you sold your soul for, Bob? I'm guessing you did it at about age five so it may not have taken much more than an ice cream cone or two.
And yes, get behind me with a "strong link" and I will not tow you.
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. You're not the only one on the line. I didn't ask to be a test pilot. I can live with your inconvenience.
No one is actually scared to fly with a standard weaklink. They may say they are, but deep down inside, they're not.
Jim Rooney - 2008/11/24 05:18:15 UTC
Well, I'm assuming there was some guff about the tug pilot's right of refusal?
Gee, didn't think we'd have to delve into "pilot in command"... I figured that one's pretty well understood in a flying community.
It's quite simple.
The tug is a certified aircraft... the glider is an unpowered ultralight vehicle. The tug pilot is the pilot in command. You are a passenger. You have the same rights and responsibilities as a skydiver.
It's a bitter pill I'm sure, but there you have it.
BTW, if you think I'm just spouting theory here, 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.
Jim Rooney - 2008/11/24 18:54:27 UTC
I'm confused. I never said the tug's ass was endangered. That's why we use 3strand at the tug's end. Using 4 strand can rip things off (it's happened). When forces are achieved that do break a 3 strand, your tail gets yanked around very hard, which does have implications as to the flight characteristics and flightpath. AKA, I have no desire to allow you to have the ability to have that effect on me when I tow you... esp near the ground.
What I said was that by using a weaklink that's stronger than the tug's, you're effectively removing your weaklink. Big difference.
The accepted standards and practices changed.
I still won't tow people with doubled up weaklinks. You don't get to "make shit up". I don't "make shit up" for that matter either.
We all play by the same rules, or we don't play.
Morningside decided that they were happy with 200lb weaklink. They changed their tug's link and they don't just pass the stuff out either. If you'd like to know more about it... go ask them.
The law of the land at comps was 130lb greenspot or you don't tow. Seriously. It was announced before the comp that this would be the policy. Some guys went and made their case to the safety committee and were shut down. So yeah, sorry... suck it up.
Pilots must use weaklinks provided by the meet organizers and in a manner approved by the meet organizers. All weaklinks will be checked and use of inappropriate weaklinks will require the pilot to go to the end of the launch line to change the weaklink.
Weaklinks should be placed at one end of a shoulder bridle. The tow forces on the weaklink will be roughly divided in half by this placement. Pilots will be shown how to tie the weaklink so that it more likely breaks at its rating breaking strength.
The curve of injuries as a function of weak link strength probably looks something like this:
OK, thanks, we've all seen it. You can stow it back up your ass now. And when you can get around to it could you perhaps refer us to some incident reports and/or videos that support your bullshit? I mean if it's not too much trouble for you.
That means there's danger on either end ... and even at the lowest (best) possible point!!
Hey Bob... Any chance you could pull another graph like that out of your ass for sailplanes?
Dr. Trisa Tilletti - 2012/06
You and I have flown sailplanes for almost as long as we have flown hang gliders. We own two sailplanes and have two airplanes that we use for towing full-size sailplanes. In all the time that we have flown and towed sailplanes, we have not experienced or even seen a sailplane weak link break.
How 'bout one comparing the safety records of gliders equipped and unequipped with backup loops? Or something equally useful and effective like shark repellent?
If you're flying a piece of "safety" equipment for which there is essentially ZERO...
See, in truck towing, a weaklink does next to nothing for you (unless the line snags).
This is because you're on a pressure regulated system... so the forces never get high enough to break the link.
This is not the case with an aerotow.
This is why the weaklink exists.
The forces of an aerotow can get high enough to tear the wings off the glider.
This is no exaggeration... it can be done.
So... if it's *only* purpose is to prevent your glider from breaking apart... which is complete and utter bullshit... but if that was it's only purpose... why then do we have them at all?
Your glider will tear the rope apart before it breaks.
It will tear the towmast off the tug before it breaks.
Your glider is capable of amazing feats of strength... it is in no danger of folding up on you.
...practical need then what's the graph look like?
Let's say that a parachute needs two hundred feet to open and one hundred percent of your flying is below two hundred feet. How do the accidental deployments that we see in this sport - which...
...are virtually certainly much more common than deliberate ones - affect the graph?
However, the shape of that curve for any particular pilot is based on their choice of equipment, conditions, and their own pilot skill.
- With USHGA regulations that you've never done shit in the way of objecting to which MANDATE that the aerotow release being able to handle twice weak link does the particular "pilot" have the legal right to use...
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.
...any bent pin piece of shit he feels like and try to compensate for it with a Rooney Link below FAA legal requirements?
- Tell me what tow conditions can be predicted for any given launch...
The weather conditions seemed quite benign. It was a typical winter day in central Florida with sunny skies, moderate temperatures and a light south west wind. Time of day was approximately 3:00. None of these conditions were even slightly alarming or would have caused any concern about launching.
...on any potentially soarable day.
- How much pilot "SKILL" does it take to stuff a bar when a piece of fishing line breaks?
Here's a tandem aerotow instructor totally lucking out from a Rooney Link pop:
Please describe the "SKILL" he employs that allows him to "SAFELY" recover from the increase in the safety of the towing operation. What's he doing that any Hang 1.0 couldn't do just as well?
A pilot with good skills at recovering from weak link breaks (as Bill mentioned above) will be operating with a curve that's much lower (less chance of injury) on the left side than a pilot with poor skills at recovering from weak link breaks.
Describe these "SKILLS" - asshole. This bullshit is like the skill involved in accelerating a car with an automatic transmission off the train tracks. You're not gonna be able to tell the difference between Tiffany the High School Senior and Dale Earnhardt Junior because the "SKILL" involved is stomping on the gas pedal. Tiffany might even be able to do a few milliseconds better as a consequence of her seventeen year old reflex speed.
Similarly, a pilot using a good quality release will be operating with a curve that's lower on the right side than a pilot using a poor release.
- Which would keep the fucking fishing line entirely out of play - as is the case in sailplaning. Sailplanes ALL have bulletproof releases and weak link breaks are statistically nonexistent while Industry hang glider releases ALL stink on ice and are ONE HUNDRED PERCENT USELESS in emergencies of any and every kind so everybody's forced up on illegally light weak links which annihilate those without good stall recovery skills and are of no measurable use in emergency situations.
- What good and poor quality releases, Bob? Bill, like his buddy Jim Keen-Intellect Rooney, tells us ALL OF THEM suck - especially homemade funky shit. So why bother bringing up that issue?
In the end, I think the best weak link strength will be based on the combination of equipment, conditions, and pilot skill.
So how come sailplanes don't spew the kind of moronic drivel you are? How come they specify 1.4 times max certified operating weight and 1.3 for surface and don't give a flying fuck about equipment, conditions, and pilot skill?
Hell show me one word from the entire 29 year twisted history of USHGA's aerotowing SOPs on equipment, conditions, skills issues...
But you - with one whole Wallaby tandem ride (where the purpose of the weak link is to provide a safe limit on the tow force such that if you fail to maintain the correct tow position (centered, with the wheels of the tug on the horizon) it will break before you can get into too much trouble) under your belt and zero interest in ever towing again - are gonna tell us all about what you "THINK" we should be doing.
So one of the goals of this chapter should be to show the full range of those issues so the individual pilot can be educated as to how to weigh them in making their own choice of weak link strength.
Yeah, use Sam and Bill to handle this one. That'll sure help make The Bob Show a safe place for people of varying ages to visit.
It's important to remember that the safest weak link strength may differ between two pilots even if they have the same weight, equipment, and conditions. Their skills matter, and I think that is very well said in Bill's post.
Shouldn't Nobody get a shot at providing some input on this? I thought his take on the issue...
Don't increase the strength of your weak-link. (Don't--Don't!)
You've got s*** for brains, Bill. Rot in Hell pigf*****.
...was pretty fuckin' spot on - assuming, of course, that those asterisks are replacing the letters I think they are (which would be h i t and u c k e r).
Sorry I haven't spent too much time tidying this up as I'm looking after my two granddaughters and both are rather fond of granddad's 'taptop'. If you spot something like degree when I mean disagree then blame my spell checker for not knowing what I meant to say!!
There are several contentious issues here but for now I'd like to concentrate on just a few.
Wow. How were you able to get this far into your response without using the term "pigfuckers" three or four times?
Just to understand where I'm coming from and to get a consistent frame of reference I am assuming:
- A system with an observer, a winch-man able to control tension, reduce power, and, in extreme situations, guillotine the line.
Fuck that. In the US we just have the glider toss his chute...
...while the winch-man runs around asking to see if anyone has a Swiss army knife he might be willing to lend out for a moment.
- A system with automatic tension control. Something able to make a reasonable effort at keeping line tensions within preset limits. Fixed line I avoid and consider dangerous.
- It's illegal for hang gliders in the UK, isn't it?
- Hell, just use eighth inch nylon parachute shroud line for your towline and a tension gauge. That's a perfectly acceptable alternative to a constant or controlled tension winch.
- Aero's inherently fixed line so the tension's all over the place. The good news is that the tow vehicle is pushing off of air instead of asphalt and doesn't weigh that much so high tension automatically slows it down a bit.
To keep things simple I'm the pilot and without an endless runway I need about 100kg of thrust to get to a reasonable height - more than this and I'm uncomfortable, much less makes for lousy height gains.
Looks like Morningside decided they weren't that happy with the two hundred pound line after all. Can't really have people just making shit up and getting out of line from decades long track records and proven systems that work.
First and foremost I disagree strongly that a pilot is always able to fly their way out of an unplanned line separation. Furthermore I say that this mentality is positively dangerous.
That would've been a good passage in which to work in a couple of "stupid pigfuckers".
Removing 100kg of thrust changes the flying mode from one of climbing under power to one of free flight with an abnormal nose up attitude in an instant, this is a fact.
Fuck you. It's an OPINION. And on The Bob Show the opinion of anybody who doesn't make The Bob Show an unsafe place for people of varying ages to visit is just as valid as anyone else's - regardless of how many people he's killed...
A pilot in a similar situation on his landing approach would considered himself in an extremely uncomfortable situation to say the least.
Or dead to say the most.
A good pilot should indeed be prepared for such an unplanned line separation (along with many other situations he might encounter during a launch). However, I have seen enough evidence to convince me that this is not always the case.
Sorry, Mike. On the Davis, Jack, Peter, Cragin, Bob Shows it's considered poor form to discuss fatalities which don't conform to conventional Hewett based assumptions.
There are situations that even perfect pilots cannot deal with...
No. That's just in free flight in which thermal turbulence is capable of overwhelming control on launch. As long as you're being tow launched using an appropriate weak link it's physically impossible for ANYONE to get into too much trouble.
...and, it is a fact, most pilots are not perfect indeed by definition most pilots are only average.
MOST pilots are weekend warrior muppets who think they can fix bad things and don't wanna start over and don't react to the inconvenience of an appropriate weak link break properly. When the pilot is a popular professional and dies the same way nobody will ever really know what happened and people who speculate are despicable scumbags.
Also conditions are not always perfect enough to allow for the textbook recovery technique to work as desired...
Bullshit. If that were really the case don't you think that imperfect conditions would've been addressed in:
- Donnell Hewett's Skyting newsletter series?
- the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden?
- Dr. Trisa Tilletti's Higher Education magazine articles?
...(pulling in hard with a bit of a wing up for example).When I say line separation I include all the things that might go wrong such as a line break, premature release and the like. Fortunately these are rare events and tow groups do all that is possibly to avoid them.
Whatever's going on back there, I can fix it by giving you the rope.
...tow groups anyway. So US aerotowing is pretty much completely off the table.
A (too weak) weak-link on the other hand is introduced by design and is, by a big margin, the most likely thing to fail.
So much so that all the crap that Bill was babbling about is statistically nonexistent.
So to summarise this part.
You don't have to do anything wrong to find yourself in a compromised situation after a link break even if you are an expert pilot. For the rest of us the situation could be far worse.
I'll say there's ZERO difference between a solid Hang 2.0 and a Davis Straub who's been at an around all this plenty long enough to understand what's what and who's who. There's not that much skill involved, all that's required can be overwhelmed in a millisecond, and the crap that wins one aerobatics and XC trophies is about as useful as a parachute at seventy-five feet.
Of the two schools of thought ...
...the first of which entirely excludes thought and acceptance of reality as components...
A non event that presents no problem verses a potentially serious issue.
The former is by far the most palatable.
Not for an industry built and for decades wobbling on a foundation of the former.
But for now, even if just to humour me, accept my pessimistic view because provided there is no trade-off, to assume there is a danger is likely to be a safer option than to assume there is none.
Yeah? Name a tuggie - or any other flavor of driver - who was ever worse off after a glider was dumped.
"Provided there is no trade-off".
You're just trading inconvenience for safety. No brainer.
To make it clear I'll say from the onset that flying with no dedicated weak-link is plain stupid.
As is having a weak link on only one end of a long bridle - like most gliders and ALL...
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!
...Dragonflies.
Also if one changes the term 'strong link' to 'one not too weak' (as used above) then there is a complete change of emphasis.
Brian,
While I appreciate your quest for the perfect weaklink, didn't we cover this already? (Again?)
Are we to go down the road of debating the quality standards of greenspot again?
Ok, for review, it doesn't matter.
Why?
Because you have nothing else.
Do I have to review why we don't tow handmade gliders?
Listen we're all perfectly aware that greenspot is not laser calibrated to 130lbs. It's bloody fishing line. Get over it. Are you flying below your perfect numbers as a heavy guy. Yes. Yes you are. Get over it.
Why?
Because it's all you've got.
Why lower numbers? Because your choice is lower or higher... and higher is more dangerous than lower.
Plain and simple. Janni, 1G, but please stay.
Now, my turn.
Name one commercially available strength rated material that can be used as a weaklink OTHER than greenspot.
Then again, Russell Brown had us double up behind him after six breaks in a row at Zapata. We couldn't figure out why we had so many breaks so quickly. Maybe just coincidence.
...somewhat excessively inconvenient at times - almost always as a matter of...
Um... If you're going to start pretending that you're discussing his accident you need to remember that Zach was a very light pilot.
...coincidence.
So to keep things very simple...
Remember you have Sam participating in this discussion. If you can't express everything you need to say exclusively in smilies then don't even bother.
...lets say I am towing with 100kg of thrust with a weak-link value of 101kg. It's easy to see that I can expect frequent breaks indeed launching might not be possible, winch tension control is not that good.
Just tie it with the knot positioned so that it's hidden from the main tension in the link and excluded altogether from the equation and you'll get 202 kilograms. Then it will still break consistently when you need it to but not inconsistently when it inconveniences you - all of the advantages of the acceptable material with none of the dangers of material twice as heavy tied without the knot being positioned so that it's hidden from the main tension in the link. Win win. No brainer.
Up the weak-link value a bit.
How would you know you're upping it?
Dr. Trisa Tilletti - 2012/06
We could get into details of lab testing weak links and bridles, but this article is already getting long. That would be a good topic for an article in the future. Besides, with our backgrounds in formal research, you and I both know that lab tests may produce results with good internal validity, but are often weak in regard to external validity--meaning lab conditions cannot completely include all the factors and variability that exists in the big, real world.
Lab testing can't tell you anything with the external validity necessary to predict what's gonna happen with all the factors and variability that exist in the big, real world. Bob - with his background in aeronautical engineering - can certainly tell you this much.
Launches are now possible but there are still frequent link breaks.
Which is where the danger curve peaks.
A bit more and breaks become just a few.
Which is where the stupid motherfuckers in this sport REALLY get lulled into false senses of security.
At this point, only for historic reasons as far as I can see, it is now deemed acceptable and anything above is referred to as a 'strong link'.
It's actually deemed MANDATORY - regardless of how many pops they get up to six consecutive...
For many years a number of us (US pilots) have felt that #8 bricklayers nylon line was not an appropriate material to use for weaklinks as it is not as consistent in its breaking strength (as far as we are concerned) as the Greenspot line used in the US.
...because once the Industry pigfuckers put crap into circulation there's no way in hell they're EVER gonna admit they were fuckin' clueless regardless of the number of people they crash, injure, and kill. And crashes, injuries, and kills have ZERO effect on lengths of track records.
I see no logical...
LOGIC? In HANG GLIDING?
...reason for stopping at that point. Why not up the tension a bit more until undesirable link breaks disappear, just like sailplane towing?
We've declared properly tied 130 pound Greenspot to be the equivalent of what sailplanes use.
Dr. Trisa Tilletti - 2012/06
There are many reasons, but for most pilots it is not because the standard 130 lb. green spot Dacron line used to make weak links for hang gliders is too weak.
What more do you want?
Naturally this does not mean exceeding or even coming close to forces needed to break the next thing in the chain.
All the more reason to use a WEAKER weaklink. If you're bending pins rather than breaking the weaklink, I have to think your weaklink is too strong (and now the pin has become the weakest link in the system
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.
Yeah?
The payout winch and other tension controlled variants were the first and one of the most significant safety devices ever to be introduced to the hang glider towing world.
But they cost MONEY. Just use eighth inch nylon parachute cord and a tension gauge. You'll be fine.
With a (trained) winch-man added I believe this launch method to be as safe, and in some instances, safer then all the other methods available.
Just as long as he's not trained to fix whatever's going on...
We were towing on the lee side of some thousand foot mountains. I had flown without problems an hour before.
I got to about a hundred feet and the glider was completely veered to the left due to the strong crosswinds from the right.
What made me hesitate and not release was having the right wing way up and being stalled and very low. I had the feeling I was going to be catapulted backwards if I released and had a clear notion I was going to hit dirt in a tailwind.
The best option seemed to be to resist the lock out and slowly bring the glider down, even if it was crooked, but another problem arose when the observer had the tow line cut when I was down to about fifty feet.
I had no chance. The glider that had been hanging on like a kite dead leafed to the ground. The left leading edge hit first, destroying it along with the nose plates. My body's impact point was the left shoulder and the left side of my head and neck.
I remained unconscious for about twenty minutes with a bloody face from what poured from my nose. The chopper arrived about an hour after the crash. I was already semi-conscious but in a lot of pain and having trouble breathing. I was hauled to Stanford (about half an hour flight time).
The toll: fracture and crushing of the upper humerus, several broken ribs, a lung pierced and collapsed by one of them, and broken C1 vertebra right by the artery. They considered surgery, but the no-surgery risk was lower - they feared a chip would rupture the artery.
...by giving you the rope.
Having a weak-link calibrated too close to the expected tow tensions only serves to overrides the far superior ironing out effect of a tension control system with a vastly inferior random and one way removal of all power.
So? Controlled tension systems with quality releases cost thousands of dollars. The price of a few inches of fishing line is a couple pennies and you can pretend that it works just as well and keeps you just as safe.
This is illogical.
Certifiably fucking insane. But...
Dr. Trisa Tilletti - 2012/06
Dr. Lionel D. Hewitt, professor of physics and developer of the 2-to-1 center-of-mass Skyting bridle for surface towing, is well respected for his knowledge of towing, bridles, and weak links.
What are ya gonna do?
So what is lost by upping the link value as above? The winch will still work limiting the tension, assuming the winch-man is something much more than some passerby...
I'll take the passerby over some total fucking asshole...
And we take off with this... We call it a weak link - many people would call it a fuse... And that fuse is all we need to tow us up. And if anything ever happened that got us overtensioned that would just break - and we'd be free flying, which is just what we like.
...like Mike Dead-Eye Robertson.
...he will be observing and protecting the pilot, the line can be chopped in extreme situations and not forgetting the pilot still has a release.
This is all before the weak-link comes into play and even then it will still break in a jam up before anything else does!
If you use those STRAIGHT pins. But then it's hard to hook up to a thick rope without using a weak link. And somebody showed Jim Keen-Intellect Rooney how to flip the pin through the loop to make it lock.
Why aren't straight pins used?
That's easy. They can't be used with anything but thin lines.
They also can't be made with anything but thin lines.
Tad loves to forget that I've actually gotten one of his to jam.
NOTHING is perfect, kids.
NOTHING is perfect kids.
As for the argument that a weak-link is there to compensate for an unreliable release* I say get yourselves a release with the same failure rate as your hang strap and this requirement will vanish.
I get tired as hell "refuting" all these mouth release and "strong link" arguments. Dig through the forums if you want that. I've been doing it for years but unfortunately the peddlers are religious in their beliefs so they find justification any way they can to "prove" their stuff. This is known as "Confirmation Bias"... seeking data to support your theory... it's back-asswards. Guess what? The shit doesn't work. If it did, we'd be using it everywhere. But it doesn't stand the test of reality.
ZC, You're right! I'm wrong! Your mind is made up! Good luck with your strong weak links! LATERS!
...we'd have hit the target a third of a century ago.
* Purpose built mechanical releases have an almost unblemished safety record on par with hang straps and side wires but some samples are not immune to poor design and construction as demonstrated by an incident observed only last month.
Probably wasn't simple enough. Get Paul Hurless to draw you a sketch showing you how it SHOULD be done. He's really great at telling everybody how great he would be at drawing sketches showing everybody how it should be done if he ever felt like drawing sketches showing everybody how it should be done.
My entire hang gliding towing experience consists of one tandem aero-tow at Wallaby Ranch ... where I was the passenger (thanks for the flight Malcolm).
Welcome to Wallaby Ranch, the first and largest Aerotow Hang Gliding Flight Park in the World! We're the aerotowing (or "AT") professionals; no-one knows AT like we do; it's all we do, and we do it everyday, year-round. This primer will teach you the basics of AT theory and technique. Our instructors have fine-tuned this system over the course of many years, while teaching thousands of people how to aerotow hang gliders.
...and world renowned expertise on matters of aerotowing in general and weak links in particular we should probably all just defer to his takes on aerotowing.
In an excessive out-of position situation, the weak link will snap before the control authority of the glider would be lost.
Davis Straub - 2013/02/08 20:32:45 UTC
You'll have to ask Malcolm to update his document. He knows better.
Even a total piece of shit like Davis who forces all his victims up on Cummings Links to keep them safe from getting into excessive out-of position situations where the control authority of the glider would be lost will occasionally make the mistake of going on the record saying that's a load of crap.
Any comment on that, Bob? If Malcolm is as full of shit as he so obviously is then how is anyone's EXPERIENCE - or lack thereof - the very least bit relevant to any discussion? Wouldn't we be at least as well and almost certainly better off listening to some jerk randomly selected at the mall?
(If somebody wants to fuck Bob over but good ask him point blank whether or not Malcolm's/Wallaby's statement has the slightest shred of validity and then watch him squirm trying to figure out strategies for getting out of actually answering the question.)
So my comments come more from an attempt to understand towing...
As for Nobody's request for me to read a document, I haven't found the time yet. I'm sorry, but I don't have time to read everything that everyone asks me to read.
...understanding towing. Guess the background in Navier-Stokes equations didn't quite cover it.
Bull fucking shit, Bob. You never have and never will give ten percent of a rat's ass about towing, understanding it, and fixing it. You're SOLE interest - just like that of your scummy moderator and elected official colleagues - is in sabotaging all progress towards sanity within this fuckin' lunatic asylum of a flavor of aviation. And don't think for a nanosecond that I don't know EXACTLY what you're doing - which is EXACTLY what you've been doing for YEARS.
...than any pretence of authority on the subject.
- Good thing you're not maintaining any pretence of authority on the subject of spelling either - yet another discipline in which a halfway intelligent ten year old wouldn't have much trouble kicking your ass.
- You didn't have any problem maintaining a pretense of authority on the subject when you told your asshole pigfucker buddy Orion Price...
I first learned about Tad Eareckson when I was Regional Director and the USHPA Board circulated a letter he had written (with intention to send?) to the FAA about some dangerous practices in hang gliding.
The Board's knee-jerk response was to try to take some kind of legal action to silence Tad. I indicated that I thought we shouldn't be sending our lawyers in as our first response, and that maybe we should have someone talk with him first. So Dennis Pagen volunteered, and I believe the matter was settled without any serious damage to the sport.
...that my efforts to get EXISTING and UNCHALLENGED REGULATIONS enforced would've caused serious damage to the sport - on top of the moderate damage I'd already done before the efforts to silence me had been fully and properly mobilized.
One of my thoughts...
Fuck you. Any and all THOUGHTS you have are geared ENTIRELY towards advancing your personal position and NOTHING more. If fifty-one percent of your potential power base is pin bending Rooney Linkers you're gonna fight to the death for bent pin "releases", Rooney Links, and pin bending Rooney Linkers.
...while mulling this all over is that the severity of the glider's response to a line break must be related to the amount of tension in the line when it broke.
- What's it matter? The worst that can happen as a consequence of ANY strength weak link break is a STALL. And we're already in full agreement that stalls are nonissues. In fact, once you've practiced them a bit and learned there's nothing to be feared, they're a total BLAST!
- Did you mull over the facts that Zack Marzec's glider's response to a Rooney Link break was a tailslide, whipstall, and lethal tumble back onto the runway and that there was not ONE SINGLE SERIOUS SUGGESTION of dumbing down Rooney Links - let alone any implementation of same? That ALL *ACTUAL* recommendations and changes which took place were towards HEAVIER weak links?
In other words, if the tension is very close to zero before the break, then the glider's response will be very close to zero after the break. Is that generally true?
Yes, Bob. If the glider's dangerously pitched up by a powerful thermal forty feet off the deck and a .005 G weak link pops he'll wind up just as dead as Tom Perfetti found himself on the afternoon of 1982/06/20 when he was on final coming into the High Rock LZ with his hands on the downtubes. So I think it would be a good idea to start thinking about .0025 G weak links.
And let's ignore the fact that if Tom had been on tow with a 1.5, 2.0, 3.0, 10.0 weak link with a winch, truck, tug in front of him he could've climbed out just fine.
Similarly, if the tension is very high at the time of the break, then that means that the force diagram before the break shows a large force along the tow line and an equally large force opposing it.
Wow. What a really impressive way of saying that when the towline tension hits four hundred pounds a four hundred pound weak link will blow. Asshole.
At the moment of the line break, the tow line force becomes zero, and the opposing force is converted to acceleration (actually deceleration in this case) according to Sir Newton's F=ma.
What a load of crap. The moment of a line break there IS NO opposing force and you have no fuckin' clue what's gonna be going on with whatever it was that was providing the opposition.
- If you snap a four hundred pound weak link trying to pull a twelve and a half ton Easter Island Moai statue it won't decelerate 'cause you didn't get it moving in the first place.
- In a surface tow the glider can have overflown a truck, winch, pulley and the towline can be pulling nearly straight back. (That's happened, people have died.) The glider, assuming the bridle's routed under the basetube, will be at in a steep dive at a high angle of attack. (If the bridle's routed OVER the basetube it'll be dead already.) If the four hundred pound weak link blows the glider will pitch up and it's angle of attack will abruptly DECREASE.
- You have no fuckin' clue where the glider was pointing, what its angle of attack/airspeed was, what the air will be doing in the following one to five seconds, how much of a gradient or wind shift there will be on the ground, how well and quickly the pilot will be able to react, how responsive the glider will be as a consequence of hook-in weight and sprogs and VG settings.
What you DO know beyond all fucking doubt is that the tow was NOT terminated by either of two PILOTS (and, YES, anybody driving a tug, boat, truck, winch, scooter is a PILOT and, not infrequently, a PILOT IN COMMAND) who are SUPPOSED TO BE qualified AND EQUIPPED...
...can kick in. And whenever a piece of fishing line overrides the decisions of two pilots to maintain thrust it's a REAL GOOD BET that the situation isn't gonna get any better and - if it's an emergency situation - that things are gonna get real ugly...
Note that in the example above if the ground had been about ten feet higher the motherfucker would've wound up six feet under it and not one single asshole in this sport would've been talking about dumbing down the Rooney Link any more than it already was.
Note also that as things turned out, BARELY, as they did, not one single asshole in this sport, including this one:
A vertical stabilizer would have saved this pilot! Double surface gliders at high speed will do this. They will say the problem is PIO but it's really DIO (design Induced Oscillation) If a pilot can loose control at any speed within the gliders VNE (Velocity Never Exceed) It is the fault of the manufacture. Sure the pilot exacerbated the DIO with PIO but the glider needs a vertical stabilizer when towing fast. Getting off of tow and slowing down (not speed up.) is the correct thing to do.
...made any reference whatsoever to the Rooney Link. What do you think the response would've been if he'd been known to have been flying a Tad-O-Link?
So the greater the line tension at the time of the break, the greater that thrust change and subsequent deceleration will be.
In fixed wing aviation deceleration is another way of saying increase in angle of attack. And moderate increases in angle of attack result in decreases in control authority - which is bad. But extreme increases in angle of attack result in stalls - which are total nonissues. So shouldn't we be going for really heavy weak links which either leave us on tow with LOTSA airspeed or dump us off tow into severe stalls with NO airspeed? It's that MIDDLE area that's the real danger.
It's like being dropped off in the middle of a lake. Either really warm in mid August so's you'll have no trouble swimming out or really cold in late January so's you'll have no trouble walking out. Definitely NOT in mid March.
Is that generally true as well?
Sure it is, Bob. Just like it's GENERALLY true that:
The strength of the weak link is crucial to a safe tow. It should be weak enough so that it will break before the pressure of the towline reaches a level that compromises the handling of the glider but strong enough so that it doesn't break every time you fly into a bit of rough air. A good rule of thumb for the optimum strength is one G, or in other words, equal to the total wing load of the glider. Most flight parks use 130 lb. braided Dacron line, so that one loop (which is the equivalent to two strands) is about 260 lb. strong - about the average wing load of a single pilot on a typical glider. For tandems, either two loops (four strands) of the same line or one loop of a stronger line is usually used to compensate for nearly twice the wing loading. When attaching the weak link to the bridle, position the knot so that it's hidden from the main tension in the link and excluded altogether from the equation.
- The strength of the weak link is crucial to a safe tow. It should be weak enough so that it will break before the pressure of the towline reaches a level that compromises the handling of the glider but strong enough so that it doesn't break every time you fly into a bit of rough air.
- A good rule of thumb for the optimum strength is one G, or in other words, equal to the total wing load of the glider.
- Most flight parks use 130 lb. braided Dacron line, so that one loop (which is the equivalent to two strands) is about 260 lb. strong - about the average wing load of a single pilot on a typical glider. And when you stick it on a bridle end you get about TWICE the average wing load of a single pilot on a typical glider.
- If you're not an average pilot on typical glider you can go fuck yourself.
- For tandems, either two loops (four strands) of the same line or one loop of a stronger line is usually used to compensate for nearly twice the wing loading.
- When the weak link is attached to the bridle with the knot positioned so that it's hidden from the main tension in the link it's excluded altogether from the equation.
Thanks for the great discussion.
You're ever so welcome, Bob. And thank YOU for once again setting yourself up as you did!
It's great to see all aspects of a topic like this being explored!!
- Oh yes, it's ABSOLUTELY FANTASTIC! And I really admire your tolerance for...
I've had to deal with your profanity, your attacks on other members, your strong weak link theories, your lift and tug theories, and your hopelessly long and repetitive posts.
...Mike's strong weak link theories - you goddam two-faced piece o' shit.
- Yeah, let's have ALL aspects of this topic explored. Just like we should have ALL aspects of the origin of species explored. If you're teaching biology in Oklahoma you should give evolutionists and creationist / intelligent design assholes input in proportion to the student population say into what's gonna be on the final. You'll have a LOT more kids getting MUCH higher grades.
- Really glad to see that you're not one of these moderators who lock down threads about weak links rather than go stark raving mad as this horse carcass is once again being exhumed and whipped mercilessly.
- Fuck you, Bob. In the close to four years of you're crappy little dictatorship's existence name ONE SINGLE advancement or improvement to hang gliding procedures or technology that's come out of it. How many of Sam Quite-A-Genius Kellner's hook-in check mirrors have been installed on gliders? Compare that figure to the number of unhooked launch incidents that have been documented in the near three years since that flash of brilliance. How 'bout making a prediction on the number of weak links that'll be swapped out for something heavier or lighter based upon what's happening there? I'm guessing about ZERO - or possibly as many as ZERO.
P.S. Ask Sam what the tension was reading on Terry...
whenever you wanted to and just fly away.
