http://www.paraglidingforum.com/viewtopic.php?t=2859
Towing safety
Stu Caruk - 2005/06/30 09:44:56 UTC
towing
Interestingly, the type of winch appears to me to be of little consequence. The worst potential for injuries that I have seen was when a truck drove over a line running from a scooter tow winch to the pilots and drug it off. It was spooling line rapidly off the scooter, the winch operator wasn't close to the winch, he was chasing after the vehicle to get them to stop. I happened to notice what was going on and ran towards the pilot on tow trying to get them to pull the release whilst grabbing my trusty pocket knife.
- And the reason you're not telling us what YOUR STUDENT was using for a weak link is because he WASN'T using a weak link. Right?
- So do we get to hear how things turned out or do we hafta tune in to next week's episode?
- Did our hero get the student to pull the release or did he hafta cut the line with his rusty - sorry - TRUSTY pocket knife?
- Or was his trusty sidekick Robin able to stop the truck?
- Had Batman instructed the pilot to pull the release thingy when it was obvious that the tow was going south and not likely to turn back any time soon?
- Had Batman equipped the pilot with a release which would allow him to reliably end such a tow?
- What weak link rating would you suggest we us to protect against scenarios involving lines rapidly spooling off of winches?
- So how many of your students have your weak links spared from subsequent incidents like that one?
Second scariest would be a scooter tow with almost all the line out and a pilot who launched and for some reason was very uncomfortable, reached for and pulled the release but never insured the line had released (it hadn't) then turned downwind peeling line off the drum until it hit the end of the spool. Fortunately the line was attached to the spool with a light weaklink which broke to prevent things from going really bad.
- Meaning that - again - there was no weak link on the student.
- Maybe he was very uncomfortable because hadn't been trained adequately to be operating at that level?
- And he very obviously hadn't been properly equipped to be operating at that level.
- Why was he using a release:
-- that he had to REACH FOR?
-- which wouldn't blow AFTER he REACHED FOR and PULLED it?
- Why wasn't he adequately trained to verify the disconnection before turning?
- What load was the release rated to handle?
- With a light weak link on holding the end of the line on the drum what was the maximum loading to which that release could've been subjected?
- What the fuck is a "LIGHT WEAKLINK" and how "LIGHT" does it need to be to prevent things from going:
-- really bad;
-- moderately bad;
-- acceptably bad;
-- hardly bad enough to be worth mentioning?
- So what would've happened if there had been a line dig and all the line didn't pull off?
- So what would've happened if the towline had snagged on something?
- Did you read about the 2011/01/15 Shane Smith fatality?
Stu Caruk - 2005/06/28 21:03:57 UTC
They provide even less protection from a line jam during the downwind phase of a step tow.
- I'm having a little trouble resolving those two statements.
3rd was a pilot who continually locked out on tow from side to side behind our boat...
So you were towing someone who couldn't fly.
...forcing us to reduce the line tension and end up with a ridiculously shallow line angle.
Maybe that would've been a real good time to just continue reducing line tension.
In the turn they...
At what point in the tow had the tow become a tandem?
...of course cut the corner to let the line go slack which forces us to run like mad and rewind the line to keep it out of the water. Snagging the line on a saialboat mast or other boat is a distinct possibility...
- If you had ended the tow when you should have there'd be a whole lot less line to worry about.
- Maybe people incapable of conducting a safe controlled tow operation shouldn't operate around other vessels.
The real problem occured at the top of the tow when the pilot release (some $15 POS... so what if it doesn't work, it was cheap!) failed to function.
- But you decided to use your boat to tow him up ANYWAY.
- So you've got a fifteen dollar piece of shit release that doesn't work at normal release tension and you're not using a weak link to limit the load going to it.
- Oh well...
Stu Caruk - 2005/06/28 21:03:57 UTC
If you carry a hook knife, which all paraglider pilots should, I'd find it hard to find a malfunction you can't solve.
...I'm sure you insisted that both of them carry hook knives so that shouldn't really have been a problem.
They freaked...
They FREAKED? BOTH OF THEM? Keeriste. If they had just remained calm and used their hook knives!
...held onto the brakes and tried to separate the release.
- Was one working the brakes while the other tried to pry and/or hack the release open?
- Do you just have people show up at the dock and say, "That looks like fun! Can I give it a try?"?
Ever see a 1 1/2 turn spin with the pilot on tow....
- Sounds like they had the wrong person on the brakes.
- Did you cut speed and tension to help them out?
...followed by the pilot running downwind...... eeeek.. Actually to be fair, a weak link wouldn't have helped here...
- Whereas properly rated and configured weak links would've eliminated all the problems and dangers of the other two incidents.
- That's alright. I really enjoyed hearing the anecdote. Most amusing.
...unless we hit the sailboat mast with the towline...
- So how many Gs do you use to make sure that nothing bad happens to anybody or anything when you hit a sailboat mast?
- Damn those sailboats anyway. Always rocketing across your stern at thirty knots oblivious to everything that's going on.
If it can happen when towing, you can bet at some point it surely will...
- Especially when you've people who can't fly and/or have total shit equipment trying to go up and unprofessional, irresponsible, negligent, clueless douchebags running stuff on the surface.
- All of those situations were inexcusable on your part, Stuart. And I don't even hear you admitting any errors of judgment or accepting any responsibility for ANY of that crap.
- So what you're saying is that it's just inevitable that a tow operation is gonna have a situation in which killing somebody is a pretty good probability.
...and pretending (hoping) that it never will is a silly idea at best.
You mean like YOU'RE about to start doing when you dismiss high tension situations at launch as products only of incompetent tow operations and not worth considering with respect to the weak link rating issue?
We need to be proactive.
Some of us HAVE BEEN proactive - for a LONG time. But we always tend to get drowned out and overwhelmed by the shit happens crowd.
We need to look to our fixed wing bretheren...
Paragliders ARE fixed wing aircraft.
...and observe why the safety record is so much better for the airlines then private aviation.
Standards, training, enforcement.
The answer is simple, they are required, and actually plan and brief for a malfunction on EVERY takeoff.
Yeah. Like...
- You're twenty feet into launch.
- You get slammed by a thermal and pitched so you're standing on your tail.
- Your three quarter G weak link blows.
What's the best way to hit the ground to best absorb the impact and yield the greatest odds of long term survival?
They assume something will go wrong and have a plan to deal with it.
Did they do a scenario with a shitheaded tow operator in the equation?
They don't skimp on safety equipment.
Yeah. They find any three quarter G weak links, they swap them out for half G weak links. Nothing but the BEST!
Towing is a well accepted practise in aviation, and yet in the US EVERY towing activity requires a specific waiver, and EVERY towing activity also requires a weaklink to be used.
Maybe if they didn't require a weak link to be used...
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
they wouldn't require specific waivers either.
Ever wonder Why?
No.
Tost Flugzeuggerätebau
Weak links protect your aircraft against overloading.
It's a pretty fucking simple issue.
I'd tend to dispute that lockouts are the worst thing that can happen with towing a paraglider.
Quite right.
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
Lockouts don't hold a candle to weak link induced stalls.
I've towed hundreds of inexperienced pilots and while watching a paraglider pilot start to lock out and head off the towline is an annoyance, it's not much of a big deal in my opinion. With a hang glider,, sure as skippy, it's a hugely big deal and likely to go really bad, really quick, but we're not taliking about towing hang gliders here are we...
The issue isn't primarily paragliders versus hang gliders. The issue is that most hang gliders are aerotowed and the tension CAN'T be reduced quickly or to any extent usefully enough to help out the glider.
But even then... Dangerous low level lockouts in hang gliding are so rare as to be virtually nonexistent - especially when you compare the volume of what aerotow operations pump through to what paragliders are putting up. And furthermore, we could pretty much totally erase them with better release equipment than the tow cartel allows people to use.
With a paraglider, if the pilot starts to diverge from the towline it's a relatively simple matter for the tow tech to reduce line tension and allow the pilot to fall back under the canopy or make it easier for the pilot to correct back on course. If the pilot doesn't correct, it's pretty simple to adjust the line tension to keep the problem from getting worse, and if the pilot fails to correct you can further reduce the tension and land the pilot. It's only a real issue of they are over water and you don't want to get them wet.
That's not that big of an issue - especially compared to what we hafta deal with.
Lockouts though aren't really a tension control issue, they are more of a heading control issue. It's unlikely that a weaklink will break soley because a pilot locks out (although I've seen them break after the pilot hits the dirt and is being drug by the tow tech) in fact it's likey that a weaklink won't break because the force won't be high enough (This also makes the case to not use them to prevent a lockout kind of mute as well though... what can they hurt here?)
Here's how they hurt...
The motherfuckers who run this sport tell everybody:
http://www.wallaby.com/aerotow_primer.php
Aerotow Primer for Experienced Pilots
The Wallaby Ranch Aerotowing Primer for Experienced Pilots - 2012/04/18
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.
so people all fly with standard aerotow weak links thinking that they'll compensate for their piece of shit releases so, not only do we kill the same number of people in lockouts, but have so many stalls and crashes that they're considered routine nonevents and - in the serious ones - attributable solely to inadequate piloting skills.
This is by the way one of the reasons we REALLY like a tow assist style bridle, and frankly we now require them to be used, unless the pilot has demonstrated their ability to launch cleanly in no wind without the device. The issue with lockouts is really most prevalent where the pilot uses an older style bridle without an assist. The glider never comes cleanly overhead unless the pilot really puts in the effort on launch. So the pilot comes into the air with the glider hanging well back and perhaps off to the side. Unless the glider is going perfectly straight, it's going to head off to the side, and because the pilot is pulled well out in front of the glider, it will take a huge correction on the pilots part to bring the glider on a more appropriatte heading. If the tow tech adds more tension at this point there is a very good chance the weak link will break.
Shithead.
THis is really BAD.
Duh.
The pilot will then pendulum backwards and pound in on their (hopefully used) back protector. If they're a little higher, the glider will surge, and the pilot will pound in on their face. A wee higher and a full frontal is possible. A lucky pilot will damp the surge, flare and land. The WRONG response from the tow tech is also to dump all the tension at this point.
And fear not! The weak link would never make a WRONG response in this situations. Weak links are INFALLIBLE. Just ask Doctor Hewett.
Tyically the pilot is pulled a bit off to one side, and in addition to the problems above they will swing sideways back under their canopy as they pound in.
Not good eh!
With a tow assist, the glider comes cleanly overhead in the first place, so it's easy to make a course correction. Secondly if the glider diverges say to the right, the assist automatically trims the glider faster on the right and helps make the correction. I often see things going bad, and know that as long as an assist device is being used I can add tension, and literally drag the glider into the direction I need the pilot to go. That's also the technique used in towing Sheba the wonderdog. She can't make a course correction, but her tow bridle can do it for her.
Without an assist device it's a whole lot more work. I'm not going to say it's impossible to lock out a glider with an assist device, although I will say I've towed some pretty lame pilots who do nothing to make a correction and are way, way off tow.
WHY are you towing pretty lame pilots who do nothing to make a correction and are way, way off tow?
By adjusting the line tension I can easily balance the tow force to keep them in the air maybe even climbing slowly while they work to get things straightened out. If they are over the water, I've seen the glider go almost 90 degrees off tow, and literally towed the glider sideways for a while till things got sorted out. You just can't go near that far over the dirt though.
LOckouts are not IMHO a terrible risk with a paraglider.
So with tow assists and people working things well on both ends of the line, light weak links aren't really a problem.
OVERTOWING A GLIDER OFF LAUNCH AND BUSTING A WEAKLINK is FAR more likely and FAR more dangerous. It places the glider in a unusual flight configuration with the possibility of a great surge with not enough altitude to recover. I don't care how good a pilot you are. If you have enough energy applied before the weak link busts, and you're too low, the results won't be pretty.
So we've got:
It's unlikely that a weaklink will break soley because a pilot locks out...
and
OVERTOWING A GLIDER OFF LAUNCH AND BUSTING A WEAKLINK is FAR more likely and FAR more dangerous.
So Stuart... THINK. The weak link is very UNLIKELY to blow when it would be highly advantageous to be off and very LIKELY to blow when coming off is extremely dangerous.
So should we be dumbing them down in hopes of making them more effective lockout protectors or beefing them up to make them less effective stall catalysts?
So now you have to think to yourself. Since the really dangerous point is right off launch with insufficient altitude to recover you want to ensure a couple things.
First, as a pilot I would like the tow tech to use the minimum force necesary to get me airborne reducing the potential for a problem.
Yeah. First reduce your thrust at takeoff so you don't take a chance of damaging your lockout protector. Brilliant.
I want to do my part to ensure my glider is cleanly overhead by doing an aggresive launch and I want to be assisted into the air, not yanked off my feet. This means I really need to do my part.
But ONLY because you don't wanna stress your lockout protector. Otherwise you'd just waddle into the air any way you could.
I assume the tow tech will try to kill me by over towing me, so I make every effort to get my foot on the speed bar immediately after launch and before I sit down (heck, I never sit down fro 50 feet or so because if the weak link brakes, things will happen so fast you won't get on your feet).
Do you assume your lockout protector will try to kill you by blowing when your tow tech is trying to kill you by overtowing you and do anything to reduce that threat level? Just kidding.
I assume that ther will be a line dig, line jam, some sucker will drive over the line, etc.
Stuff happens though so lets face it. Right after you lauch, somce sucker on a jetski will cut off the boat driver and they will be distracted momentarilly and not look at you the pilot. The scooter tow operator will sneeze and jam the throttle, the throttle on the winch or boat will jam wide open. you name it, it will happens, and right about that time you will trip and fall on launch.... something that just never happens. If you WISELY used a wek link, it will be a non event.
Of course it will.
- What's a wise rating for a wek link that'll turn all this stuff into a nonevent?
- Why should we be listening to recommendations on wise wek link ratings from somebody who can't even spell wek link?
You will fall, get drug a ways, and the link will bust.
- What's the farthest you can get drug an a three quarter G weak link before it busts?
- If you had a release actuator in your teeth how far would you get drug?
- How often have people been drug at your operation?
- How often have people been drug at your operation when the assholes on the ground were doing a halfway competent version of their jobs?
- Do you have guillotines on any of your equipment?
If you've run really hard on launch, are standing upright in youir harness, you've used an appropriately sized weak link and the link breaks, you will experience a minor surge, hopefully flare and land.
You are so totally full of shit, Stuart. I sure wish you wrote a lot less.
If you have no weaklink, somethings got to give and if it';s an 1100# towline (the minimum recomendation for safely towing a paraglier BTW) you can get drug a long ways, or you will have a wicked surge.
NO. Something DOESN'T *HAVE TO* GIVE. Even if the asshole on the upwind end tries as hard as he possibly can he'd probably be unable to MAKE something give on a bet. So how 'bout just shutting the fuck up?
I simply for the life of me can't fathom towing without a weaklink.
You don't have a snowball's chance in hell of beginning to fathom the sole purpose of a weak link. And if you don't have a clue what the purpose of a piece of towing is you have absolutely no fuckin' business towing anything or anybody - including yourself - anyway.
As a USHGA tow supervisor (just a shmuck that can issue tow administrator, tow tech, and TL endorsements)...
Great. Thank you once again, USHGA.
...I side with USHGA which requires the use of weaklinks for ALL towing operations.
- Why am I not the least bit surprised.
We need to look to our fixed wing bretheren...
- Do you also side with USHGA's departure from the rest of fixed wing aviation in which only top end values for weak links are specified - even though you're starting to get a slight clue that it's the bottom end where there REAL problems are?
Now this of course I'll admit means spit in the US, since we don't need to comply with this or be USHGA pilots to tow (unless we are flying under the USHGA tandem waiver) it comes from years of accumulated experience and a standardized training regimine.
And if you are USHGA you're perfectly free to ignore and/or make up whatever rules you feel like anyway 'cause no matter how many people you get killed with by violating the regulations no one will ever hold you accountable for anything.
I look back to the weird days when we started towing. Glider lines were stretching, pilots were pounding in, waeklinks...
Yet another entertaining spelling of the word. Ya know... anal and asshole don't mean the same thing.
...were rarely used becasue they were understood, we slingshot paraglider pilots into the air, sometimes using polypro or nylon to try to dampen out the surge (whilst actually ensuring an almost impossible means of accurate tension control, and guranteeing a bucking bronco ride aloft)...
Precisely. Wanna have a few words with Mark Stucky on this issue?
...and compare it to the ridiculously simple graceful means we have of towing aloft today... I don't want to go back there.
I'm not following you here.
- You used to blast gliders into the air with rubber bands with crappy tension control and no weak links but the only problem you were having was having the glider bounce all over the sky as you climbed out.
- Then you went to Spectra and got everything under control.
- Except your releases were/are crap so you couldn't blow tow on your decision when you fuck up a launch and are getting dragged.
- So you then added three quarter weak links which you felt would blow you of before you got dragged too far and introduced the issues of three quarter G weak link failure and the ensuing stalls.
Can you see where I'm going with this?
Pervious posters are 100% correct.
Pervious posters CAN'T be one hundred percent correct - by definition. (I love that one.)
You can go to different areas of the country and see vastly differnt towing practises. Things are gradually being more standardized and safer as more tow pilots travel around, and current techniques and equipment are adopted.
Bullshit. It's a race to a totally homogenized bent pin bottom.
I love all the history the hang glider pilots have taught us.
You would.
I just wish that many pilots would quit trying to tow paragliders the way we've towed hang gliders for years. Towing a paraglider is NOTHING like towing a hang glider.
Bullshit. The principles of towing paragliders, hang gliders, sailplanes, and ten year old kids' kites are IDENTICAL.
Paragliders don't need high line tensions to launch...
Most of the time - no. But that don't make it a great idea to flush the option down the toilet.
...we don't wan't anything to do with stretchy spongy springy towlines...
Talk to Mark.
...we really don't have pitch control...
Sometimes one point aerotowers don't have what they really need either.
...so tow assist bridles are very helpful...
We call them two point aerotow bridles.
...and weaklinks are ALWAYS a good thing to have in the system.
You shoulda shut the fuck up while you were still sounding halfway intelligent.
For all the arguements against them, why not just toss in say a 250 or 300 pound link.
Yeah. Sure.
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
Let's just toss something in that'll probably blow when we get dragged to compensate for our shit releases.
You should never see anywere near that tow force.
Nah. The only ways you could see anything like that kind of tow force would be if...
I assume the tow tech will try to kill me by over towing me, so I make every effort to get my foot on the speed bar immediately after launch...
- the tow tech tries to kill you by overtowing you before you can get your foot on the speed bar;
I assume that ther will be a line dig, line jam...
- there's a line dig or jam;
...some sucker will drive over the line, etc.
- some sucker drives over the line;
Right after you lauch, somce sucker on a jetski will cut off the boat driver and they will be distracted momentarilly and not look at you the pilot.
- right after you launch, some sucker an a jet ski will cut of the boat driver and he and his brand new clone will both be distracted momentarily at you, the pilot;
The scooter tow operator will sneeze and jam the throttle...
- the scooter tow operator will sneeze and jam the throttle;
...the throttle on the winch or boat will jam wide open...
- the throttle on the winch or boat will jam wide open;
...you name it, it will happens,
- you get gusted or hit with a thermal or dust devil.
Hard to imagine any of those sorts of things happening and the glider pitching up thirty feet off the deck and overloading a THREE HUNDRED POUND weak link.
Sure, you need to change them after every 3 or 4 tows (QUIT WAITING TILL THEY BREAK YOU CHEAP BOZOS) but they are so cheap it's worth changing every flight.
Yeah, now that Stu has pulled a number or two out of his ass with no fuckin' clue as to what he's talking about and zilch in the way of grade school logic or common sense, you'll be just fine with them as long as you CHANGE them every three or four tows (YOU CHEAP BOZOS).
As a pilot I almost always carry my own weak link and tie on a new one rather than use the shabby old weathered piece of shoelace that's been installed for the last year.
You're not a PILOT, Stuart. A PILOT knows what the fuck he's doing and talking about You're not even a qualified tow operator - nowhere even close. You're a dice roller.
Maybe it's because I'm the fat guy that breaks the links... maybe it's because they never get changed that they break, and at the worst times.
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," and that "More people have been injured because of a weak link than saved by one."
Maybe it's because they're below what would be legal for sailplanes and under half what would be safe for paragliders. Shithead.
Towing is IMHO...
Oh good. More of your OPINION. And just when I thought you were all out.
...one of the safest means of getting aloft in a paraglider.
Could be fifty times as safe if the people who were running it weren't a bunch of morons.
It's as safe as you want to make it though, and weaklinks should make things safer not more dificult.
Yeah. Anybody gets killed at your operation it's not gonna be as a consequence of anything you told or sold him or did to fuck things up at the other end.
On the flip side though I know people will always skip this important safety deveice.
I wish.
I make my living dealing with this mentality.
You make a killing when you write this crap and people trust you.
I get to do a service call in the morning for a company that kept blowing the 30 amp fuses on a machine. After blowing half a dozen fuses (which cost $4.67 each after all) they replaced the fuses on each of the 3 legs of 480 volt 3 phase AC power supply with short pieces of copper water pipe. Those cheap fuses protected several thousand dollars worth or motors, drive amplifiers, and H bridge assemblies, which sadly the copper pipe (I'm guessing they would blow at probably 1000 amps or more) didn't protect.
- How many amps would it take to blow your glider and how many amps is the fuse you're using on it?
- If the navigation system in your cockpit normally draws 18 amps but occasionally draws 22 and the manufacturer specifies a 30 amp fuse, how great an idea is it to use a 20 amp fuse and try to fly through a mountain pass in a blizzard?
- Shithead.
I get to make lots of money on their stupidity.
And hospitals and funeral homes make lotsa money on YOUR stupidity.
With a paraglider, the weaklink works like a similar fuse. It's designed to break before catastrophic damage can occur. Removing it allows what should be a minor incident to potentially be catastrophic. The only difference is the guy getting rich if we're lucky will be the surgeon. If we're unlucky it could the mortician.
Shithead.
If you've got a bad weak link break incident that doesn't involve a hang glider (we all know that's very bad on launch after a lockout especially), or doesn't involve overtowing I'd love to hear about it and a pure rational explanation as to why weak links are so dangerous.
- So now we can take items "a" through "g" out of the equation 'cause they're no longer compatible with the two numbers you just pulled out of your ass.
- Your so far beyond the reach of rational explanations that it melts everybody's circuitry down just thinking about it.
Fortunately everybody is entitled to do what they want.
Always a good thing in aviation - especially when other people's asses are on the line. I'll tell Jeremiah Thompson's family hi for you.
They can tow with or without weaklinks, unless or course they come towing with us. We clearly see the benifit of weaklinks...
- Who the fuck is "WE", Stuart? How come the rest of US aren't in this conversation speaking for themselves?
- People who use that pronoun are usually liars. (Bob - for example - is hugely into that pronoun.)
- If you so clearly see the benefit of weak links, how come your explanation of them to us sounds like snow job and demented babbling?
...and tow assist style bridles, and require their use (as well as life jackets for over the water) at all times.
Get fucked.
If your local towing group still insists on the need for huge towline tensions on launch...
- So the only way you'll be able to experience huge towline tensions on launch - even once - is if your local towing group INSISTS on them.
- Who are these local towing groups who are insisting on these huge towline tensions? Are we hearing complaints about them on the forum. Or are they just fictitious products of your fevered imagination like the clueless pilots we have in hang gliding who get killed because they try to save bad situations instead of blowing tow at the first sign of trouble?
...and you're having problems breaking weaklinks I'd love to invite you to call us if you happen to be near Ridgefield, WA. We'd love to have you come out and tow with us, or arrange to tow with one of the local schools that teach by using tow launching as their principle means of instruction. you can find us through
http://www.TowMeUp.com
Yeah, TowMeUP - the Western Hemisphere's last word on paragliding weak links. See them emerge fresh from Stu's ass.
Tow high
Stu
Yeah. And make sure nothing unusual happens before you get there.
