Tad Eareckson wrote:Hewett was (is) totally fucking clueless with respect to how the tow force vectors actually worked. His bogus hypothesis was (is) that you're effectively connecting to the glider system's center of mass and this would make the glider autocorrecting in roll. (The more out of line you are the better. 'Cause the autocorrecting force keeps getting stronger.)
-- with a one point connection on the harness suspension about a third of the way up from the pilot a lot more elegantly (which is what the Brooks Bridle (developed in the UK around the same time as and totally independently from the Hewett junk) did)
Where'd the UK (beyond Mike Lake) end up on vectors and autocorrecting?
OK I'm a newbie to towing but it's that moment that I come off the cart when I feel I don't have a third hand free to dump the line if it all goes wrong and I'm tipped over further than I am confident I can recover from with the wire pulling the wrong way. Doing the 'lockout drill' in level high flight showed me the line certainly wanted to fly the glider but reaching for the release with some height wouldn't be a tenth the problem.
I wondered if just moving my 'bike brake lever' to the basebar rather than having it on the down tube to eliminate the head turn to locate it would help but the place I'd want to put it is used by the cart so that's not on either. I've played at snapping a hand to the tube release on the chest loop but if the line is pulling in a funny direction that could become a fumble. I just don't fancy holding something in my mouth. That's trying to implement a motor skill with no background. I'd worry about it not working under pressure even if it was my 'normal' way to release.
Yeah, Mike's from the UK - Norfolk - and was very much in the thick of the pilot connection evolution of hang glider towing in the East Anglian neck of the Great Britain Woods.
The UK ended up in an even worse shit heap than the US did. It jumped on the Hewett snake oil bandwagon and dumped the Brooks Bridle branch of towing evolution and erased it from history as thoroughly as they were able.
The Brooks Bridle needed a bit o' work but even if it had never evolved beyond 1.0 the vast majority of individuals who've been snuffed in towing crashes wouldn't have been.
They were a fair way to being equally clueless/backwards on theory / vector stuff...
* HIGH degree of roll control on tow, that INCREASES with line tension. You can go more than 45 degrees off line and get back on again at full tension, and launch safely 30 degrees off wind. In addition, the bridle tends to pull the pilot over to the correcting side of the control frame to give recovery.
...but if that doesn't influence equipment design and/or training - which it didn't in their case - it makes no difference in the field.
After hesitating a bit for not really understanding the question I'll answer it yes.
I was having a problem with how one defines u$hPa operatives and distinguishes them from victims. But I'm just about at the point at which everybody active in hang gliding - save for Team Kite Strings - is a u$hPa operative.
Anybody with a reasonably functional brain who enters the sport should immediately become aware of its pervasive overwhelming stench. And Kite Strings is way more than a faint blip on the radar and we've bent over backwards for years in outreach efforts and gotten little above being pissed all over in return.
This autocorrecting center of mass bridle bullshit is EXACTLY the same hands-free launch run roll control bullshit Ryan is selling. We DEMOLISHED that little motherfucker on that issue and exposed him as a liar and fraud. And nobody cared. More Kool-Aid please.
So yeah. Only USHPA and their operatives. Only 99.99 percent of the people involved in the sport.
Every tension limiting device discussed up to now consists of mechanical components, has a limited range, or relies upon human operation. Every one of these tension limiting devices is subject to failure. Please correct me if I am wrong, but it is also my understanding that there are a large number of tow pilots today who are depending upon smooth air, rope stretch, boat speed, mechanical devices, and ground crews to provide the tension limitation control for their flights. Well, in the author's opinion that is just not good enough. Skyting requires the use of an infallible weak link to place an absolute upper limit to the towline tension in the unlikely event that everything else fails.
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." Well, I for one have been saved by a weak link and would not even consider towing without one. I want to know without a doubt (1) when I am pushing too hard, and (2) what will break when I push too hard, and (3) that no other damage need result because I push too hard.
Furthermore, I will not use a mechanical weak link no matter how elaborate or expensive because there is always the possibility that it may fail to operate properly. In skyting we use a simple and inexpensive strand of nylon fishing line which breaks at the desired tension limit. There is no possible way for it to jam and fail to release when the maximum tension is exceeded. Sure, it may get weaker through aging or wear and break too soon, but it cannot get stronger and fail to break. If it does break too soon, so what? We simply replace it with a fresh one.
A properly designed weak link must be strong enough to permit a good rate of climb without breaking, and it must be weak enough to break before the glider gets out of control, stalls, or collapses. Since our glider flies level with a 50 pound pull, climbs at about 500 fpm with a 130 pound pull, and retains sufficient control to prevent stalling if a weak link breaks at 200 pounds pull, we selected that value. Of course, a pilot could deliberately produce a stalled break at 200 lbs, just as he can stall a glider in free flight. But if he is trying to limit his climb rate and the forces exceed the break limit, the glider simply drops its nose to the free flight attitude and continues flying. If the weak link breaks (or should the towline break) at less than the 200 pound value, the effect is even less dramatic and controlled flight is still present.
Most people are amazed at how small a string is needed for the weak link of a tow system. In fact, many people upon seeing it in operation for the first time make a comment something like "Don't you need something a little stronger than that? It's going to break!" But, of course, that's the whole point, it's supposed to break. And in order to break at about 200 lbs, it needs to be a single strand (loop) of No. 21 or 24 size nylon cord or a double strand (loop) of No. 12 or 15 size. For our glider we have found through trial and error that a loop of No. 18 braided nylon twine is ideal. A single strand of this twine is rated at 140 lb breaking strength, so a double strength loop should break at 280 pounds. In practice, we have found that because of the knots, it actually breaks at about 200 lbs when tied in a loop and attached to the towline.
Although we suspect that the same weak link would work well with other gliders, we have not had the opportunity to run tests on other gliders to varify this suspicion. Until such tests can be run, we strongly recommend that considerable caution be exercised in determining the correct weak link for any other glider. One should start with a line that definitely breaks too soon, gradually increasing the strength until a point is reached where the glider is able to climb at a good rate without breaking the weak link, but where no stall occurs when the weak link does break.
Obviously, more work needs to be done in this area, but even so, we have found our current system to be quite satisfactory and able to provide the necessary tension limiting and regulation needed for safe and enjoyable flight under tow. Our next article will discuss various methods of attaching the towline to the glider and why the skyting method is to be preferred.
WEAK LINK
Every tension limiting device discussed up to now consists of mechanical components, has a limited range, or relies upon human operation.
- You mean like when you're using an engine on the plane for regular powered flight? (By the way... Don't the powered aircraft folk prefer LOTSA power for the planes for, amongst other things, wider safety margins in dicey situations?)
- Sounds like what we need here is a weak link. That'll certainly take care of the limited range issue. And I'd certainly never wanna go up in any aircraft without solid range limiting devices. Just think of the degree of trouble one would be able get into otherwise.
Every one of these tension limiting devices is subject to failure.
- Name something on an aircraft that ISN'T subject to failure. This is why we have stuff like engineering, HGMA glider certification and pilot competency standards, preflight inspections.
- Yeah Donnell. That's why the best we can do on a release system is "Reliable". But no problem whatsoever with the weak link. It can be Infallible because its catastrophic failure is always an unmitigated success. Really gotta admire the genius level logic involved on that issue.
Please correct me if I am wrong...
Why? What good would it do? You'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." And that hasn't done shit to put the slightest dent in your position. So I don't have the slightest fucking clue what it would take for anybody to correct you about anything.
...but it is also my understanding that there are a large number of tow pilots today who are depending upon smooth air, rope stretch, boat speed, mechanical devices, and ground crews to provide the tension limitation control for their flights.
- Anybody who thinks that "rope stretch" can be of any positive value in tension limitation control is a total fucking moron.
- Kinda like with Assisted Windy Cliff Launch flights? A pilot and his crew assessing a potentially lethal situation and responding, adjusting, initiating accordingly?
- Tell me why we NEED tension limitation control in this era of HGMA certified gliders.
- Note the conspicuous absence of mentions of back end releases and front end guillotines. Guess they get covered under the category of "mechanical devices". And what do we all know about the reliability of "mechanical devices" from the mainstream crowd?
-- Got any incident reports to support the idea that what we really need is an Infallible Weak Link to defuse any of these situations? Just kidding.
Well, in the author's opinion...
Yeah, the author's OPINION. Here we go with the whole Infallible Weak Link fiasco.
...that is just not good enough.
And perish the thought that we cite any actual real world incident reports to support the author's opinion. (See above.)
Skyting requires the use of an infallible weak link to place an absolute upper limit to the towline tension in the unlikely event that everything else fails.
- Yeah, the UNLIKELY EVENT that EVERYTHING ELSE fails. Let's use an Infallible Weak Link that succeeds one out of every four normal smooth air launches to make totally sure that we're perfectly safe in those UNLIKELY EVENTS in which EVERYTHING ELSE fails 25 percent of the time. That way you can totally bury the operation in multiple thick layers of shoddiness and incompetence and come away with lotsa really good flights.
- Fuck these unlikely events in which everything else fails. If you go up with ANYTHING that can fail in the course of any flight in halfway sane conditions you deserve to die. Ditto for going up in totally insane conditions.
If a sidewire, downtube, leading edge, hang loop fails you're dead. (And if you use a backup loop to protect yourself from a primary failure you deserve to be.) If a towline or bridle element or connection fails that's always a good thing - an inconvenience at worst, a weak link that functions even more safely than the designated one.
We know what you're talking about - your Reliable, easily reachable, Rube Goldberg, placebo release. It's failed before you've gotten off the ground 'cause there's zero chance of you being able to use it at any time you really need to.
It took this bullshit sport around three and a half decades from when you started publishing this rubbish to get to a reasonable facsimile of your unlikely event in which everything else fails - 2015/03/27 Kelly Harrison kiddie tandem thrill ride at Jean Lake. And the Infallible Weak Link didn't do shit to mitigate anything. Goddam Fallible Parachute would've easily defused the situation down to mega-embarrassment level and allowed two people to walk away physically unscathed but it never occurred to him to deploy it.
- Skyting itself is the most monumental failure in the entire word history of aviation.
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,"...
- Well fuck... That's just an ARGUMENT. It's not like anything like that has ever actually happened out in the real world. Just a bunch o' uppity hang glider pilots wanting to argue for the sole sake of argument. Certainly no need to take a quick glimpse at any fatality report summaries in the magazine to see if there's any substance behind this argument. Whenever I hear anybody start to argue about anything I just start walking away.
- And anyway... Why would anybody in his right mind wanna be climbing hard on tow? The whole idea behind hang glider towing is to limit your climb rate as much as possible. Ya gotta have SOME consideration for the focal point of your safe towing system ferchrisake.
...and that "More people have been injured because of a weak link than saved by one."
Oh. You've HEARD that more people have been injured because of a weak link than have been saved by one. Not just an argument - but people who've actually been doing this shit out in the real world on major scales. Curiously mirrors the argument that you've heard about weak links always breaking at the worst possible time, with the gliders climbing hard in near stall situations. Probably just a coincidence. Don't worry about it.
Well, I for one have been saved by a weak link...
Yeah? You owe your life to a weak link success? You'd have been fuckin' dead otherwise? So how come you never considered this incident worthy of a report anywhere? It was a fuckin' TOW so there was at least one other individual involved. So how come we never heard anything about it from him/her either?
Yet we've got a pretty goddam detailed account in your 1983/03 edition of you breaking your right arm in a lockout violent crash your Infallible Weak Link did no more shit to prevent or mitigate than your Reliable Release. Guess Infallible Weak Links are good for saving lives but not so much for saving arms. Fair enough, I guess.
And of course this was a 200 pound weak link, right? A 300 pounder would've been totally useless, wouldn't have broken when it was supposed to.
If MY life had been saved by a weak link I'd be telling people every fuckin' detail of the incident - tow power flavor, location, operator, release, conditions, pullout altitude, what the fuck went wrong and why...
Saying that one has been saved by a weak link is like saying one was saved by a parachute - 'cept twenty times worse. These are dice roll situations. If there's any truth to this whatsoever it had to be a lockout at altitude with a Reliable Release. The Infallible Weak Link broke at two hundred feet before anybody at either end was able to operate any of the placebo equipment so we just credit the fishing line with preventing certain death.
And now it occurs to me that you're not even telling us whether this incident occurred before or after you figured out - mostly for the wrong reasons - that the lower attachment needed to be shifted from the basetube to the pilot. If before then funny you're not using it to illustrate how dangerous the old system. And it can't be after 'cause your Center of Mass system weight-shifts the pilot to under the high wing and neutralizes lockouts before they can get started, right?
...and would not even consider towing without one.
And I wouldn't even consider towing someone counting that much on a piece of fishing line to prevent him from crashing. Also wouldn't even consider towing with a Reliable Release which required me to effect an easy reach in a lockout situation no matter what the fuck I was using as the focal point of my safe towing system.
I want to know without a doubt (1) when I am pushing too hard, and (2) what will break when I push too hard, and (3) that no other damage need result because I push too hard.
So what happens when you get off of the tow? How the fuck do you have the slightest clue regarding pushing an HGMA certified glider to the seven G level you'd need to reach or exceed to break it?
I remember back in the fall of 1980 shortly before you started composing these articles when we were all towing entirely off the frame when KHK flight school manager Randy Cobb - who was a major fucking dickhead - towed Doug Rice...
11-12317
...up on a Yarnall winch in high wind. These bozos paid out several thousand feet of line until they got to the last loop which was tied to the drum. No weak link, the glider's release was overloaded, fuckin' douchebag Randy running around trying to find a knife, the winch was lifted off the ground. (Prequel to Lin Lyons / Harold Johnson / Mission Soaring Center state-of-the-art equipment fiasco...
...of 2013/06/15. ('Cept in the latter there was zilch tension involved. (Which, now that I think of it, makes it a really excellent illustration of how little misaligned tension is needed to pile drive and kill somebody. (Read good freakin' luck with your Infallible Weak Link.))) I think the separation occurred when Doug was finally able to pry his release open.
So Donnell... In light of that just how are we defining "pushing too hard" with respect to damaging shit?
You wanna know without a doubt (1) when people are pushing too hard, (2) what will break when they push too hard, (3) what other damage may result because they push too hard? Watch some films of blown aerobatics maneuvers. What will break when they push too hard - assuming they properly preflight the glider to make sure the sidewires are in good shape - is an outboard leading edge section or cross spar. After that what happens is pretty much academic 'cause it can range largely as a matter of luck from floating down under canopy with no more issues worth mentioning to the glider reduced to scrap metal and rags and the passenger dead on impact.
And if you think for a nanosecond that you're likely to come on tow within a fraction of what it takes to overload a glider to the extent you see in these aerobatic disaster films you really need to consider taking up another hobby.
Furthermore, I will not use a mechanical weak link no matter how elaborate or expensive because there is always the possibility that it may fail to operate properly.
- What the fuck are you talking about? Is there ANYTHING in the historical record anywhere about elaborate, expensive, mechanical weak links for hang gliders? Sailplanes have been using weak links since the beginning of time - a section of line or a calibrated metal insert that will blow before the plane gets overloaded. How did this get to be rocket science for hang gliders?
- You also furthermore won't use a mechanical release elaborate and expensive enough to operate properly because you've got a simple and inexpensive strand of nylon fishing line which breaks at the desired tension limit far before there's the slightest possibility of you getting into too much trouble.
In skyting we use a simple and inexpensive strand of nylon fishing line which breaks at the desired tension limit.
- Toldyaso.
- Yeah, simple and inexpensive always works best for anything involved in hang glider towing.
- And do please define for the next few decades worth of hang glider pilots what tension limit we should be desiring.
There is no possible way for it to jam and fail to release when the maximum tension is exceeded.
- Amazing. Let's get this guy an NAA Safety Award for developing a loop of fishing line which has no chance of failing to fail as a compensator for a release that has no chance of succeeding.
- Don't worry, Donnell. Hang gliding will very quickly figure out how to configure weak links to enable them to jam...
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!
...and fail to release when the maximum tension is exceeded. And I never once heard you speaking up about that flavor of unfathomable stupidity.
- You know sumpin' else that often works really well to keep the maximum tension from being exceeded? The fuckin' runway.
Sure, it may get weaker through aging or wear and break too soon...
And we've already figured out how to ignore any dangers concerning...
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
Tost Flugzeuggerätebau
- Use only the weak links stipulated in your aircraft TCDS or aircraft manual.
- Checking the cable preamble is mandatory according to SBO (German Gliding Operation Regulations); this includes the inspection of weak links.
- Replace the weak link immediately in the case of visible damage.
- We recommend that the weak link insert are replaced after 200 starts: AN INSERT EXCHANGED IN TIME IS ALWAYS SAFER AND CHEAPER THAN AN ABORTED LAUNCH.
- Always use the protective steel sleeve.
...premature releases due to substandard, defective, damaged weak links. We just call them inconveniences and train our pilots how to react to them - in simulations on tandem flights in smooth air at two thousand feet at thirty percent of maximum Tandem Standard Aerotow Weak Link capacity.
...but it cannot get stronger and fail to break.
Quite unlike all those elaborate, expensive, mechanical weak links that were all the rage back in the late Seventies.
If it does break too soon, so what? We simply replace it with a fresh one.
I met Zach up at Morningside.
Zach was hard not to like... and hard not to like instantly.
He will be sorely missed.
Not really. (Note that we've got an annual XC Bohl fly-in at Wharton but not a Marzec anything at Quest, Currituck, anywhere else. Doesn't seem fair as the latter did absolutely nothing wrong and the cause of his untimely death remains a total mystery to this very day - over five and three quarters years after the fact.)
A properly designed weak link must be strong enough to permit a good rate of climb without breaking, and it must be weak enough to break before the glider gets out of control, stalls, or collapses.
- Yeah Donnell, I'm totally sure it does. If only someone could figure out how to properly design one.
- This is total bullshit. Who the fuck talks about "properly DESIGNING" a weak link? (Someone who doesn't have the slightest fucking clue how to properly design a release system is my best guess.)
- Before the glider gets out of control? Where'd that come from?
I want to know without a doubt (1) when I am pushing too hard, and (2) what will break when I push too hard, and (3) that no other damage need result because I push too hard.
There's nothing in that statement about the glider getting out of control. And we've already debunked it as total rot. So how can the glider possibly get out of control with a Center of Mass bridle system that pulls the glider back to center before it can even think about getting off center?
Since our glider flies level with a 50 pound pull, climbs at about 500 fpm with a 130 pound pull, and retains sufficient control to prevent stalling if a weak link breaks at 200 pounds pull, we selected that value.
- Sure it does, Donnell. Instantly subtract 200 - or even 130 - pounds of thrust from a glider climbing at 500 fpm you can be one hundred percent POSITIVE that it will retain sufficient control to prevent stalling - no matter what the fuck else is going on. Like, fer instance, a pilot who was pushing too hard. That's been scientifically proven beyond any shadow of a doubt over the course of three out of five flights total in smooth evening air.
- Got that, people of varying ages? 500 fpm with a 130 pound pull - 70 pounds under Infallible Weak Link.
- But I'm a bit confused by an issue here...
THE SKYTING CRITERIA
2. CONSTANT TENSION
The tension in the towline must remain essentially constant throughout every phase of the towed flight.
5. GRADUAL TRANSITIONS
The transition to and from tow as well as any variations while on tow must be gradual in nature.
9. ADEQUATE POWER
The system must contain a source of power adequate to maintain a safe mode of flight while under tow.
If there are absolutely no downsides under any imaginable circumstances to going from 200 pounds tension to ZERO in the space of a millisecond then how could Constant Tension, Gradual Transitions from tow to free flight, Adequate Power to maintain a safe mode of flight possibly be of the slightest importance to anything under any imaginable circumstances? And why are you emphasizing these issues in an absolute minimum of 25 percent of your safe towing criteria points?
Of course, a pilot could deliberately produce a stalled break at 200 lbs, just as he can stall a glider in free flight.
- Yeah Donnell? How 'bout a blast from a monster thermal fifty feet off the deck? What could that deliberately do?
- Bull fucking shit. Lemme tell ya sumpin'... You CANNOT produce a stall in smooth air free flight without going to a lot of effort. Doing so is a requirement for a Three rating and it's supposed to be done at a minimum of 500 feet in smooth air. You gotta try hard to pull it off and doing so goes against all of your piloting instincts. (Although, gotta admit, it's kinda fun when you actually do it.) When you pop an Infallible Weak Link you can pretty much count on a stall and a bit of passenger mode time while your glider's recovering flying speed. And the ones that increase the safety of the towing operation shortly off the cart in AT result in a lot of downtube snapping crashes.
Also... Stalls ON TOW don't exist in the real world. Even this glider:
Well yeah... Hard to imagine a pilot on tow not constantly working his ass off to limit his climb rate. The higher you go the farther you have to fall. Every two-year-old has a solid grasp of that concept.
...and the forces exceed the break limit, the glider simply drops its nose to the free flight attitude and continues flying.
- Like a fuckin' lawn dart when the pilot's been doing a proper job of limiting his climb rate. And if you're not much good at that consider taking a climb rate limiting clinic from Jim Keen-Intellect Rooney.
- Of course it does. But our pilot has no fucking clue whether or not he's pushing too hard until his Infallible Weak Link kicks in to let him know. So what's the limit on THAT simple nose dropping phase - one might refer to it as a STALL - in THAT scenario? What result did you get on that test flight? You obviously did a few of those 'cause you've determined that a 200 pound weak link will let you know when you're pushing too hard - pushing hard enough to approach the point at which you're closing on breaking your glider.
- Got that, people of varying ages? Under Skyting theory "pushing too hard" is synonymous with not "trying to limit your climb rate". But don't worry, you've got an Infallible Weak Link to let you know when you're pushing too hard. Absolute total fucking lunacy. And this is all in...
12. SUITABLE ENVIRONMENT
The system must be operated only within the environment and under the conditions for which it was designed.
...glassy smooth air.
- Also catch this... Donnell needs an Infallible Weak Link to tell him when he's pushing too hard, right? Pushing too hard while he's trying to limit his climb rate to make sure his glider won't stall when the safety of his towing operation is increased? This motherfucker knows goddam well that when his 200 pound Infallible Weak Link let's him know that he's pushing too hard the feedback will be a fatal whipstall at low altitude or a fatal whipstall and tumble at high.
- And remember... He's climbing at 500 fpm with a 130 pound pull. So at 70 pounds under Infallible Weak Link he still stalls unless he's trying to limit his climb rate. 130 pounds is very close to what I measured for Yours Truly going up behind a 914 Dragonfly. And all of us know bloody goddam well what happens when we're running straight, staying level with the tug, in smooth air and the focal point of our safe towing system decides to increase the safety of the towing operation. Anybody need anything else to convince him what a total crock this business about a 200 pound weak link being able to prevent us from experiencing an inconvenience stall is?
If the weak link breaks (or should the towline break) at less than the 200 pound value, the effect is even less dramatic and controlled flight is still present.
- It just did. It just broke at 130 pounds. And we still stalled.
- Yep. Just make sure to adhere very carefully to Skyting Criterion 12.
- Oh! So the effect of blowing a 200 pound Infallible Weak Link IS, in fact, DRAMATIC. Just not all THAT dramatic. And here I was thinking that when you're properly trying to limit your good rate of climb you don't even stall. I guess we're just talking about a mildly dramatic dip while regaining a modest degree of airspeed.
Most people are amazed at how small a string is needed for the weak link of a tow system.
Totally amazing. You can just BARELY make it out at the loose end of his pro toad bridle. That's a REALLY safe one - right at the bottom of the legal range.
In fact, many people upon seeing it in operation for the first time make a comment something like "Don't you need something a little stronger than that?
Not that one, fer sure. It totally baffles me why people insist on trading off safety for convenience to that extent. You'd think the people at Quest would know better than to permit that degree of recklessness at their operation by this point in our history.
But, of course, that's the whole point, it's supposed to break.
Right. In the unlikely event that everything else fails. And ONLY in the unlikely event that everything else fails. Every other tow...
Due to the rough conditions weak links were breaking just about every other tow and the two tugs worked hard to eventually get everyone off the ground successfully.
...in rough conditions. Double the number of launches needed get the gliders up through the kill zone you double the safety of the towing operation. Also helps teach those assholes not to push too hard. And the tuggies...
We had six weaklink breaks in a row at Zapata this year. Russell Brown (tug pilot, tug owner, Quest Air owner) said go ahead and double up (four strands of Cortland Greenspot). He knows I used his Zapata weaklink in Big Spring (pilots were asked to tell the tug pilot if they were doing that).
...not to pull too hard.
And in order to break at about 200 lbs, it needs to be a single strand (loop) of No. 21 or 24 size nylon cord or a double strand (loop) of No. 12 or 15 size. For our glider we...
One glider, multiple pilots. How come you're not identifying and crediting the other members of your flight testing team?
...have found through trial...
Trail. You're using the old obsolete spelling.
...and error that a loop of No. 18 braided nylon twine is ideal.
No fucking doubt whatsoever. Hard to argue with a track record that long.
A single strand of this twine is rated at 140 lb breaking strength, so a double strength loop should break at 280 pounds.
Unless you consider the actual PHYSICS involved when you start throwing bends and knots into the equations.
In practice, we have found that because of the knots, it actually breaks at about 200 lbs when tied in a loop and attached to the towline.
- Perfect. As proven beyond all doubt over the course of an extremely long track record.
- Who the fuck is WE? And why aren't WE coauthoring this article?
- Most of the rest of us have found that a single loop blows at around the line test rating - half of what two strands would do if it weren't for the ugly reality of bends and knots. So it's a pretty safe bet that what you've been reporting as 200 for your fake testing is actually a lot closer to 140. And that's consistent with what we're seeing in the way of Infallible Weak Link success rates in the stuff you're publishing in your newsletter.
Although we suspect that the same weak link would work well with other gliders, we have not had the opportunity to run tests on other gliders to varify this suspicion.
Why do you need to run tests? You've determined that a 200 pound weak link works well for a 200 pound glider. How can this NOT be totally linear such that a 250 pound weak link works equally well for a 250 pound glider? Isn't that EXACTLY the way sailplanes have done this since the beginning of time?
Until such tests can be run, we strongly recommend that considerable caution be exercised in determining the correct weak link for any other glider.
Fuck yeah. You certainly don't wanna be using an incorrect weak link in the unlikely event that everything else fails. No telling what could happen.
And these tests, it now occurs to me, were NEVER run - by Donnell and his little south Texas crowd or anyone else anywhere. His tests, results, conclusions were and are total bullshit. Let's assume that he actually went through some motions. He would've towed up to a safe altitude on a fixed length towline, signaled the truck to accelerate, held some back pressure on the bar, waited for the fishing line to pop, recovered from the modest stall, declared the test a success. That's all that could be done 'cause it's impossible to scale a weak link to do all the crap Dennis Pagen and Bill Bryden claim it can and does in their bullshit excellent book.
And the mainstreamers never have done and never will do lockout testing on weak links because:
- there is no weak link rating that can prevent a potentially lethal lockout - even with the air as smooth as a baby's butt
- the motherfuckers don't wanna document that, due to the rapid loading increase, a two G weak link will blow a tenth of a second later than a one G weak link.
Donnell wanted a placebo safety device because he lacked the competence to engineer and produce an airworthy release system. And he served as an excellent model for the mainstream culture.
One should start with a line that definitely breaks too soon, gradually increasing the strength until a point is reached where the glider is able to climb at a good rate without breaking the weak link, but where no stall occurs when the weak link does break.
...already broken your arm in three places on the first effort.
This is total bullshit. He's saying that a properly designed weak link is strong enough to permit a good rate of climb and will only break if you deliberately push too hard - in which case it will, of course, obviously, STALL. It's a total nonsense feedback loop. He's got this lunatic pie-in-the-sky concept of an Infallible Weak Link and then runs these totally undocumented "test flights" to convince himself of the legitimacy of his snake oil.
Obviously, more work needs to be done in this area...
Nah, Donnell. You've obviously got it totally nailed.
You didn't do any actual testing. ACTUAL testing is a royal pain in the ass. Even something as straightforward and seemingly no-brainer as weak link strengths is astoundingly time and labor intensive. You've gotta set up a rig, slowly and carefully dial up the tension to get accurate numbers, record the results. And everybody who actually does this for the purpose of getting legitimate results does multiple tests on the same configurations to determine ranges and averages. And they present their data and tables online.
We've got ABSOLUTELY NOTHING from Donnell or anyone else on this. He just ran some fake trials to legitimize his concept of what could be accomplished with an Infallible Weak Link. And nobody else in the entire history of the sport - before or after these fake trials - has ever made the slightest pretense of ever doing anything along these lines. And you can expand that to sailplanes and paragliders.
...but even so, we have found our current system to be quite satisfactory and able to provide the necessary tension limiting and regulation needed for safe and enjoyable flight under tow.
- Yeah, you found that well before you actually put anything in the air.
- And we've quite satisfactorily and successfully ignored all the arguments and real world incidents which reveal our expectations, predictions, conclusions to be pure unadulterated rot. And down the road in the Skyting newsletter reports whenever there's an account of a horrendous lockout incident Donnell will conclude that the Infallible Weak Link must've been accidentally doubled and no one will ever call him on anything. Nobody ever tells him, "No Donnell! It was a SINGLE! These things do not and can not prevent gliders from getting into dangerous attitudes and positions!"
- I got news for ya, Donnell... There's no such thing as safe and enjoyable hang glider flight under tow. It's an inherently unstable and dangerous configuration. It's a necessary evil people - 'specially flatlanders - use to reach workable soaring altitude and start engaging in safe and enjoyable flight NOT under tow. Nobody ever asks a winch, truck, tug driver if he can slow things down a bit so's he can enjoy the safe and enjoyable tow a little longer.
And what people are MOST afraid of is, not surprisingly, what causes the most carnage at all Infallible Weak Link based towing operations. The focal point of one's safe towing system suddenly increasing the safety of the towing operation at the expense of a bit o' inconvenience.
Our next article will discuss various methods of attaching the towline to the glider and why the skyting method is to be preferred.
Don't bother, Donnell. You've got this Infallible Weak Link issue so totally nailed that we're all totally good with whatever else you wanna have us do.
Much as I hate to draw comparisons between this guy and a total piece o' shit like Rooney... You sure can draw a lot of extremely straight lines.
- Opinions.
- First person plural.
- Unidentified confederates.
- Trust us. We know what we're talking about.
- If it doesn't mesh with whatever I/we happen to be pulling outta my/our ass(es) at any given moment it's just some stupid muppet who feels like arguing with me/us.
- Trial/Trail and error. Our track record is now long enough for us to dismiss any noncompliant viewpoints, opinions, videos, facts, fatality reports.
- Any real world field data which shows are opinions to be pure unadulterated lethal crap is studiously dismissed and/or ignored.
- All scenarios are smooth air.
- Stall is a total nonissue with respect to weak link success. The only assholes who stall upon the instantaneous loss of a couple hundred pounds of thrust are the ones who aren't exercising proper towing skills - like maintaining a good rate of climb while trying to limit one's climb rate.
- The weaker the safer - any mild stall is gonna be even milder. Thus no bottom limit necessary. If it breaks too soon it's a minor inconvenience at worst.
- Designing a release system upon which a pilot can trust his life has been, is now, will forever be beyond the scope of human imagination - let alone of engineering capability. If it could be done we'd have done it already.
When you first read this crap without knowing the score - as pretty much all of us did at the time and all of the mainstreamer assholes still do today - you think...
- Physics professor. Obviously knows what he's talking about.
- Articulate enough. Tension limiting. Sounds solid. And hell, he sure got the part about running the lower attachment to the pilot right.
It isn't until you totally toss the mindset you probably had and all of your assumptions about his legitimacy and REALLY read critically what he put down that you realize what a total load o' crap it is. I've been working on this post on and off for several days and the more you find and realize the more you find and realize times ten. Very time consuming but the more you do it the better you get at identifying total crap and its patterns regardless of the discipline flavor.
This letter is a follow-up of my original accident report of Lemuel Lopez's fatal hang gliding accident in order to confirm and correct various aspects of that earlier report. After interviewing the witness, consulting with the police investigator, and inspecting the equipment and crash site, I believe the following facts are in evidence:
On October 13, 2010, at approximately 6:30 pm CDT, Lemuel Lopez age 45 was killed while towing a Wills Wing Falcon hang glider on a public road just north of Edinburg, Texas. Prior to the accident, he had taken 6 hang gliding lessons from me and logged some 38 flights totaling about 10 minutes in 9 months. He had progressed to the point of towing up to as high as 100 ft with consistently good foot-launchings, climb outs, straight flights, releases, and landings. He was able to handle and make corrections for light turbulence, mild wind gradients, and slight cross-winds, but he had not advanced to the point of making major corrections or banked turns. He was progressing well in ground school and was fully aware of the risks of trying to tow on his own. That was why he was taking professional lessons and why he tried very hard to duplicate the system he was training on and to follow the procedures he was learning. Unfortunately, the system he had acquired was unproven and the experience he had acquired was inadequate for him to properly evaluate the weather conditions and to tow safely on his own.
Only after the accident did I learn that his primary release was a make-shift "Linknife" constructed from a thin plastic tube with two single-edged razor blades inserted parallel to one another inside. It was activated by a rope attached to the pilot's harness on the left side, similar to the way he had been trained. His secondary release was a high quality folding utility knife with the standard one-inch blade. His payout winch was home-built with a wheel for adjusting the brake tension but with no emergency tension release and no hook knife to cut the line.
On the evening of the accident, the pilot and driver setup the towing system, adjusted the winch tension, and tested the pilot primary release several times to see that everything was working properly. The winds were reported to be variable with maximum speeds estimated to be below fifteen miles per hour. The pilot was eager to fly, but waited until a lull in the wind before giving the signal to accelerate. The pilot launched westward on an east-west paved roadway with grass fields on both sides. The take-off was good and the pilot climbed to approximately 25 ft with a ground speed of 20 to 25 mph before drifting to the right, out of sight of the driver who was looking through the rear-view mirror. The driver immediately looked over her shoulder only to see the glider in a steep bank to the right. By the time the driver could stop the pickup, the glider had crashed in the grass field approximately 100 ft to the right side of the tow road.
Inspection of the equipment after the crash showed that the right wing had broken where it joins the cross-bar, that the keel had broken near the hang point, and that the control bars had been mangled. An autopsy revealed that the right side of the pilot had numerous broken bones and that there was a severe head injury in spite of the pilot wearing a safety helmet. Inspection of the site revealed that the towline was approximately 250 ft long at the time of the accident and lined up with the crashed glider with its free end approximately 100 ft from the glider. The weak link had been cut and was lined up with the glider and towline, approximately 30 ft from the glider.
Analysis of the above facts suggests that the primary cause of the accident was the weather conditions. Although we do not know the direction of the wind at the time of the accident, the fact that the pilot launched westward suggests that the wind at the time of take-off was from the west. However, the prevailing wind at that location is from the southeast, so there is a reasonable probability that the wind at 25 ft was stronger than that at take-off and from the left. If that were the case, it would have caused the glider to drift and bank to the right as observed. In any case, the fact that the wind was variable with speeds approaching 15 mph would likely have produced a significant wind gradient when launching from a lull. Even if the wind gradient were head on, it would have caused the glider to climb rapidly and the pilot to pull in hard on the control bar to keep from climbing higher. In either case, if the pilot had tried to release at the first sign of trouble as he had been trained to do, then he would have taken his hand off the left down tube long enough to release. If his make-shift release failed to release immediately, his continued pull-in on the right side of the control bar would have produced a strong roll and turn to the right as observed. The amount of time from the initiation of the roll-out until the impact on the ground could only have been a matter of seconds, probably about 5 seconds. The glider would have accelerated during the roll-out and the pilot would have impacted on the ground head-first on his right side at approximately 40 mph. It is doubtful that the pilot had time to even consider using his back-up release. In all probability, the primary release finally functioned immediately before impact or upon impact, cutting the weak link too late for the pilot to have any chance of recovery or survival.
Donnell Hewett
Revised Accident Report 10-24-10
This letter is a follow-up of my original accident report...
Which we can read where? Presumably you submitted it to u$hPa.
In 2009 there were several serious hang gliding accidents involving pilots on the HG forum (or who had close friends on the forum that reported that these accidents had occurred). In each case there was an immediate outcry from forum members not to discuss these accidents, usually referring to the feelings of the pilots' families as a reason to not do so. In each case it was claimed that the facts would eventually come out and a detailed report would be presented and waiting for this to happen would result in a better informed pilot population and reduce the amount of possibly harmful speculation.
In each of these cases I have never seen a final detailed accident report presented in this forum. So far as I can tell, the accident reporting system that has been assumed to exist here doesn't exist at all, the only reports I've seen are those published in the USHPA magazine. They are so stripped down, devoid of contextual information and important facts that in many cases I have not been able to match the magazine accident report with those mentioned in this forum.
The end result has been that effective accident reporting is no longer taking place in the USHPA magazine or in this forum. Am I the only one who feels this way?
Exactly what good were you expecting to come of that move?
I know I saw this revision right after it came out 'cause I quoted chunks of it on the Houston dump before its douchebags voted me off the island 2010/11/19. Almost certainly have the full report archived somewhere. But before now the only site at which it was publicly accessible was this UTC-minus-four one.
...of Lemuel Lopez's fatal hang gliding accident...
Fatal hang gliding what?
...in order to confirm and correct various aspects of that earlier report.
Lemuel Lopez was a wonderful person with an adventurous spirit who took six hang gliding lessons from me and logged some thirty flights totaling about ten minutes in nine months. He was progressing well with consistently good take-offs, climb outs, straight flights, releases, and landings. He was also progressing well in ground school and was well aware of the risks of trying to tow on his own. Therefore, I was shocked to learn that he had built himself a towing system and was killed while using it to tow in Edinburg (some 100 miles away from me in Kingsville).
I have filed an accident report to USHPA and am continuing to investigate what happened. So far I have learned that he was towing with his own unproven towing system accompanied only by an inexperienced driver. He foot-launched successfully and climbed to an altitude of about 100 ft on a 250 ft towline. When the driver could no longer see the pilot in the rear view mirror, the driver stopped and may even have backed up somewhat before getting out of the pickup to watch the flight. The pilot apparently tried to release without success by cutting his weak link with a pocket knife. He continued to fly straight ahead with the towline draped over the control bar still attached to the pickup. When the towline tightened, the glider nosed down and the pilot crashed head first into the ground. He was killed on impact.
As stated previously, I am continuing to investigate the incident to confirm the above report because I have had no opportunity to interview the only eye witness, namely, the driver who obviously has been distraught over the tragedy.
Good bet that's it.
After interviewing the witness, consulting with the police investigator, and inspecting the equipment and crash site, I believe the following facts are in evidence:
On October 13, 2010, at approximately 6:30 pm CDT...
2010/10/13 23:30 UTC
...Lemuel Lopez age 45...
1965/07/15-2010/10/13
...was killed...
Fatally Inconvenienced.
...while towing...
Nah, he'd finished towing shortly before.
...a Wills Wing Falcon...
Size?
.. hang glider on a public road just north of Edinburg, Texas.
Police are investigating the death of an Hidalgo County lawyer killed while hang gliding in Edinburg.
Lemuel Lopez died along the stretch of Constitution Street and Highway 281 Wednesday evening. Police say he was in a hang glider being pulled by a pickup truck.
Constitution Street by that name no longer exists. I've so far been unable to find ANYTHING about it. "Highway 281" is US 281 which is now also through the relevant area Interstate 69C. There's also a Business 281 which splits off from the main drag north of town in the ballpark of 26°20'38.17" N 098°08'52.27" W. I'd guess that we're talking a bit north of that. As things happen I'll be on a birding trip at the usual time of year that takes in Edinburg Scenic Wetlands and I'm hoping that I'll be able to properly nail things down then.
Prior to the accident, he had taken 6 hang gliding lessons from me and logged some 38 flights totaling about 10 minutes in 9 months.
Super. An average of a bit under sixteen seconds per flight. Who could ask for more.
He had progressed to the point of towing up to as high as 100 ft with consistently good foot-launchings...
Until just now I've been assuming this was a platform launch. It was a foot launch. Holy shit! That sure would explain a lot of things.
...climb outs, straight flights, releases, and landings.
Most of which could be accomplished by a sack of potatoes.
He was able to handle and make corrections for light turbulence, mild wind gradients, and slight cross-winds...
See above.
...but he had not advanced to the point of making major corrections or banked turns.
By the time I'd racked up my first eight and three quarters minutes - on Jockey's Ridge under Kitty Hawk Kites - I'd scored my Two and was making hard banked well coordinated turns at the ends of soaring passes and was invited to come back as an instructor.
That's what I was referring to when I commented on turns near the ground elsewhere. I see so many landings where a low turn from base to final is just standard. And almost all of us have either seen, or know of someone who caught a wingtip or otherwise landed while in a turn. It's so dangerous.
In learning to fly the sailplanes, I had it drilled into me that below 200 feet, my options did not include anything more than maybe a very slight turn to avoid hitting an obstacle. Like 30 degrees from my heading may. A slight bank.
I see hang gliders make 90 degree turns from base to final at maybe 50' - 75' AGL fairly often. And I always cringe. Turns down low definitely appear to be something (from my very limited experience) that our sport needs to take more seriously in terms of avoidance.
Keep up the great work, Donnell.
He was progressing well in ground school...
Since he wasn't getting much in the way of progressing in any actual flying.
...and was fully aware of the risks of trying to tow on his own.
Apparently not.
That was why he was taking professional lessons...
Meaning he was paying for them - and nothing more. As a matter o' fact...
Donnell Hewett - 1981/10
MY PRIORITIES
Those of you who do not know me personally may wonder - if skyting is really all that it's claimed to be - then why don't I spend more time, more money, and more effort in developing it to its completion? The reason is simply a matter of priorities. Development of the skyting technique, as important as it is, simply is not at the top of my list of priorities.
My first priority belongs to Jesus Christ, the Son of God, my Savior and Lord. Considering all He has done for me and the love we have for one another, I can do nothing less than commit my life and all that I have to Him and His service. If you know Him personally, then I'm sure that you understand my feelings and will agree that Jesus beats anything this world has to offer - including hang gliding. If you never come to meet Him, then ask someone to introduce you - believe me, until you do, you don't know what you're missing.
My second priority belongs to my family. Helen, my wife, is the greatest companion any man could hope for, and has filled my life with happiness throughout the eleven years we have been married. My daughters, Tahnya (ten years old last October), and Tammi (eight years old last June), are also important in my life. I love all three of my "girls" as well as my parents and my inlaws, so that if it ever comes to a choice between my family and skyting, then hang gliding will lose every time.
My third priority belongs to my profession, I am a professor at Texas A&I University and teach physics, astronomy, and solar energy. I am also conducting research in the field of solar energy in an attempt to develop some truly cost effective solar energy devices (including a solar air conditioner). Since these activities are my primary means of support, are obligations I have voluntarily accepted, and are both enjoyable and fullfilling to me as a person, I consider both my teaching and my solar energy research to be more important than my involvement in hang gliding.
Skyting, therefore, is number four in my list of priorities. I still consider it to be important, both for providing me with a means of personal relaxation and recreation, and for providing others with an opportunity for safe and accessible hang gliding. But in my life, skyting and its development will just have to accept the fact that it gets the time, the money, and the attention that remains after I have met the needs and the obligations associated with the higher priority items mentioned above.
That is NOT someone who has any business taking payment for aviation instruction. And if you ever did anything about restructuring your priorities then I never heard anything about it. Everything I've taught here - for free - has gotten enough of my top priority attention and effort for me to be 100.00 percent certain of its validity. And I defy you to find a punctuation mark to indicate otherwise.
By the way Donnell... How has having the death of this guy on your conscience affected all those other priorities of yours? Does Jesus think you've done a stellar job? Has it helped your family relations? Good career move? Fruits of your decades of labor more secure now?
...and why he tried very hard to duplicate the system he was training on...
- Which didn't include a platform - 'cause you were teaching him great foot launch skills.
- Yeah? Wanna tell us about the areas in which he came up short? Roll control might've been one if you'd actually been teaching him anything about it.
...and to follow the procedures he was learning.
- All of which were totally solid and based on total solid aeronautical theory.
- Have you looked at any of the procedures of other tow operations around the planet and found every last set of them vastly inferior to all of yours?
You have a predilication for using scare tactics and pure speculation in some of your accident interpretations. You seem to expect that people to accept your equipment and ideas based on your convictions before they're proven.
Chris McKee - 2007/05/22 13:24:03 UTC
I give up ... What exactly is your point in this whole thread? And what relevance did the accident report have to with this thread? Your logic train has derailed and I'm jumping off before it goes over the cliff. Fly how you want, with what equipment you want, blah blah blah. When you start showing empirical data with proven and qualitative results instead of clouding the issue with conjecture, misquotes, and speculation maybe I will be more inclined to listen, but right now it just seems you are grasping at straws and I have no clue what the point in all of this is.
My only point here is that Tad's releases have not been extensively tested, and at least in my experience with them, are not safe.
I just don't want pilots to think that his weak links are entirely the answer. Tad is very smart, and is trying to address the problems he sees, so he should get kudos for that. But be very careful before you buy into the "great-new-weak-link-thing."
Dr. Trisa Tilletti - 2012/06
What we have covered in this article is practical information and knowledge gleaned from the real world of aerotowing, developed over decades and hundreds of thousands of tows by experts in the field. This information has practical external validity. Hopefully, someone will develop methods and technology that work better than what we are using as standard practice today. Like the methods and technology used today, it is unlikely that the new technology will be dictated onto us as a de jure standard. Rather, to become a de facto standard, that new technology will need to be made available in the marketplace, proven in the real world, and then embraced by our sport.
"Proven" is THE top weasel word in the sport. Who the fuck ever proved this one:
Donnell Hewett - 1982/09
In addition to the above mentioned roll and yaw tendancies, there is some sideways force on the pilot due to the body line. This is illustrated below:
As can be seen, this sideways force tends to pull the pilot over to the correct side to make the glider turn naturally in the proper direction.
Donnell? You are the LAST person ever in this sport who gets to talk about whether or not anything's been PROVEN.
- You call his system "unproven" but you don't cite one dust particle's worth of evidence to suggest that there was the slightest relevant issue.
- If we got a do-over on this one and had only the option of putting a guy on the back of the truck with a hook knife we'd take it - wouldn't we? But you don't mention that issue 'cause he duplicated your system and your system doesn't feature a guy on the back of the truck with a hook knife.
...and the experience he had acquired was inadequate for him to properly evaluate the weather conditions...
Bull fucking shit. You don't have him getting up over 25 feet. There ain't much rocket science level expertise necessary for assessing threat level within that range.
...and to tow safely on his own.
Compare/Contrast with:
John Kelly Harrison - 53375 - H5 - 1996/10/23 - Joe Greblo - PL TFL TPL AWCL CL FSL RLF TUR XC - ADV INST, TAND INST
Only after the accident did I learn that his primary release was a make-shift...
Makeshift? The implication that it wasn't up to Peter Birren standards and thus was major issue in this crash? And that Lemmy was a bit of a douchebag?
..."Linknife" constructed from a thin plastic tube with two single-edged razor blades inserted parallel to one another inside.
That's a copy of this report on Peter's cult rag. ZERO discussion. It was a total Linknife and Peter's not gonna acknowledge this one 'cause he doesn't wanna fuck up his perfect safety record with a really ugly fatality like this one. And he's also on the record having Donnell and his Skyting Criteria as walking on water.
It was activated by a rope...
A ROPE? What was it? Half inch? Three quarters? Think it was really up to the task? He calls it a rope 'cause that helps him paint this guy as substantially clueless.
...attached to the pilot's harness on the left side, similar to the way he had been trained.
- Well, no problems there then. Doesn't get much more easily reachable than that. Well done on that part of the training, Donnell.
- This was a Skyting Bridle. Lower junk routed under the control bar to the hips, make-shift "Linknife" out to aft of the tow ring.
His secondary release was a high quality folding utility knife with the standard one-inch blade.
Excellent. A razor-sharp cutting tool that can slash through lines in an instant. Really critical in a lockout emergency at 25 feet.
His payout winch was home-built with a wheel for adjusting the brake tension...
Which you use to regulate towline pressure, right Donnell? (You wouldn't believe how backwards I had those two terms before I got into hang gliding.)
...but with no emergency tension release and no hook knife to cut the line.
No hook knife. So the driver had no chance of stopping the truck and getting to the spool in time to cut the line. So many missed opportunities on this one.
On the evening of the accident, the pilot and driver setup...
"Set up" is two words.
...the towing system, adjusted the winch tension, and tested the pilot primary release several times to see that everything was working properly.
It wasn't 'cause he was using a make-shift "Linknife" but they figured that one outta three was plenty good enough.
The winds were reported to be variable with maximum speeds estimated to be below fifteen miles per hour. The pilot was eager to fly...
After the nine months of stagnation to which you subjected him? I imagine he probably was.
...but waited until a lull in the wind before giving the signal to accelerate.
On a platform launch the driver asks the pilot if he's good to go, the pilot affirms, the driver accelerates the truck and the glider.
The pilot launched westward on an east-west paved roadway with grass fields on both sides.
Probably not anymore. I wasn't able to find a good candidate.
The take-off was good and the pilot climbed to approximately 25 ft with a ground speed of 20 to 25 mph before drifting to the right, out of sight of the driver who was looking through the rear-view mirror.
If that had been a platform launch the rear-view mirror would've been totally useless a second after he'd popped the nose release. Also note that there's no mention of an airspeed gauge or the airspeed at which the glider popped off.
The driver immediately looked over her shoulder only to see the glider in a steep bank to the right.
How do you think it got like that?
Donnell Hewett - 1982/09
In addition to the above mentioned roll and yaw tendancies, there is some sideways force on the pilot due to the body line. This is illustrated below:
As can be seen, this sideways force tends to pull the pilot over to the correct side to make the glider turn naturally in the proper direction.
I thought that the farther off line you got the more effective the Skyting Bridle was in getting you back to center. Too much adverse yaw maybe?
By the time the driver could stop the pickup, the glider had crashed in the grass field approximately 100 ft to the right side of the tow road.
Who cares? The time to inspect the equipment is before you head out. And if it's not the best doable you don't head out. And this was pretty much total crap from head to toe.
...showed that the right wing had broken where it joins the cross-bar, that the keel had broken near the hang point, and that the control bars had been mangled. An autopsy revealed that the right side of the pilot had numerous broken bones and that there was a severe head injury in spite of the pilot wearing a safety helmet.
Are you sure it was an actual safety helmet and not just one of the purely cosmetic ones?
Inspection of the site revealed that the towline was approximately 250 ft long at the time of the accident...
Must've undergone a helluva lotta shrinkage. Really quickly too.
...and lined up with the crashed glider with its free end approximately 100 ft from the glider. The weak link had been cut...
- By a make-shift "Linknife"? Go figure.
- I thought it was supposed to break before you could get into too much trouble. And by the time he was able to cut it with his make-shift "Linknife" he was obviously in way too much trouble. Must've been a Tad-O-Link.
...and was lined up with the glider and towline, approximately 30 ft from the glider.
Analysis of the above facts suggests that the primary cause of the accident was the weather conditions.
The primary cause of the "accident" was that he was foot launching. It's REALLY HARD to fuck up a platform launch.
Although we do not know the direction of the wind at the time of the accident, the fact that the pilot launched westward suggests that the wind at the time of take-off was from the west. However, the prevailing wind at that location is from the southeast...
Pretty weak.
...so there is a reasonable probability that the wind at 25 ft was stronger than that at take-off and from the left.
If he'd gotten airborne on a halfway competent platform launch it wouldn't have mattered. He'd have been proned out with tons of airspeed and the glider would've weathervaned into the direction it needed to go.
If that were the case, it would have caused the glider to drift and bank...
No. But if it had - based on what you've told us about your "training" of him - he would've probably been worth shit in correcting. You could've had him just running into a fair wind doing S-turns to get him reasonably well wired for roll control. This one's sounding a lot like 2010/06/26 / Packsaddle / John Seward.
...to the right as observed. In any case, the fact that the wind was variable with speeds approaching 15 mph would likely have produced a significant wind gradient when launching from a lull.
Sure. Whatever you say.
Even if the wind gradient were head on, it would have caused the glider to climb rapidly and the pilot to pull in hard on the control bar to keep from climbing higher.
- Fuck yeah! The LAST thing you wanna be doing on a tow launch is climb rapidly in a headwind. Makes my skin crawl just thinking about it.
- Climb rapidly? Wasn't he using a properly designed weak link...
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." Well, I for one have been saved by a weak link and would not even consider towing without one. I want to know without a doubt (1) when I am pushing too hard, and (2) what will break when I push too hard, and (3) that no other damage need result because I push too hard.
Furthermore, I will not use a mechanical weak link no matter how elaborate or expensive because there is always the possibility that it may fail to operate properly. In skyting we use a simple and inexpensive strand of nylon fishing line which breaks at the desired tension limit. There is no possible way for it to jam and fail to release when the maximum tension is exceeded. Sure, it may get weaker through aging or wear and break too soon, but it cannot get stronger and fail to break. If it does break too soon, so what? We simply replace it with a fresh one.
A properly designed weak link must be strong enough to permit a good rate of climb without breaking, and it must be weak enough to break before the glider gets out of control, stalls, or collapses. Since our glider flies level with a 50 pound pull, climbs at about 500 fpm with a 130 pound pull, and retains sufficient control to prevent stalling if a weak link breaks at 200 pounds pull, we selected that value. Of course, a pilot could deliberately produce a stalled break at 200 lbs, just as he can stall a glider in free flight. But if he is trying to limit his climb rate and the forces exceed the break limit, the glider simply drops its nose to the free flight attitude and continues flying. If the weak link breaks (or should the towline break) at less than the 200 pound value, the effect is even less dramatic and controlled flight is still present.
...to prevent him from climbing in excess of a good rate?
In either case, if the pilot had tried to release at the first sign of trouble as he had been trained to do...
- Oh. You trained him to TRY to release at the first sign of trouble. What's he supposed to do after he tries? Let go of the control bar and prepare for impact?
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.
IMPORTANT - It should never be assumed that the weak link will break in a lockout.
ALWAYS RELEASE THE TOWLINE before there is a problem.
Now you're supposed to always release the towline BEFORE there is a problem. ALWAYS. If you wait until the first sign of trouble to try to release it's already way too late.
- You've just defined and suggested a scenario of:
Even if the wind gradient were head on, it would have caused the glider to climb rapidly...
as a sign of trouble. And you've told him to try to release at the first sign of trouble. So where do you get the idea that he might have been doing NOTHING in the way of trying to release and instead pulling in hard on the control bar to keep from climbing higher?
- Right Donnell. At the first sign of any kind of trouble the one-size-fits-all remedy is to try to release.
Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974
"A bad flyer won't hurt a pin man but a bad pin man can kill a flyer." - Bill Bennett
"Never take your hands off the bar." - Tom Peghiny
"The greatest dangers are a rope break or a premature release." - Richard Johnson
What's the worst that could happen?
...then he would have taken his hand off the left down tube long enough to release.
- It's a foot launch. Fucking obviously never went prone.
- What the fuck do you think is gonna be going on a couple seconds prior to a really spectacular fatal lockout impact when he takes his hand off the left downtube long enough to (TRY TO) release?
If his make-shift release...
Yeah Donnell, Keep reminding us that it's a MAKE-SHIFT "release". We might not have gotten it the first time.
...failed to release immediately...
Why would it have? The motherfucker "tested the pilot primary release SEVERAL TIMES to see that everything was working properly." Tell me how it could possibly NOT have been working properly. Did he use cheap Bronze Age X-Acto knife blades in his make-shift "Linknife"?
...his continued pull-in on the right side of the control bar would have produced a strong roll and turn to the right as observed.
And he'd have been too fucking stupid to see what was going on and try to bring the glider back into something remotely resembling control.
The amount of time from the initiation of the roll-out until the impact on the ground could only have been a matter of seconds, probably about 5 seconds.
No shit. And if it had been a platform launch there'd have probably been about five seconds worth of acceleration before the truck had been brought up to launch speed.
The glider would have accelerated during the roll-out and the pilot would have impacted on the ground head-first on his right side at approximately 40 mph.
Definitely should've been using a better safety helmet.
It is doubtful that the pilot...
The what?
...had time to even consider using his back-up release.
It's pretty fucking doubtful that the pilot was 0.01 percent stupid enough to even think of his high quality back-up release.
In all probability, the primary release finally functioned immediately before impact or upon impact, cutting the weak link too late for the pilot to have any chance of recovery or survival.
Bull fucking shit. His primary make-shift "Linknife" "release" finally functioned the millisecond he pulled its "rope". But he was pretty much toast no matter what a second and a half after he got airborne.
See what happens when you let the commercial interest responsible for the train wreck investigate and submit the incident report on the train wreck? Notice the strong smell extremely similar to the one we got when Steve Exceptionally-Knowledgeable Wendt did the report on Holly Korzilius? These things are ALWAYS written by motherfuckers terrified of getting their asses sued outta existence - and it really shows.
---
2019/10/02 13:00:00 UTC
That discussion ended less than three weeks before Zack first lit up Kite Strings - 2010/11/23 05:23:34 UTC. And three weeks into the discussions - 2010/12/14 23:51:17 UTC - I've quoted from it.
Ridgerodent puts in an appearance - 2010/10/28 03:20:39 UTC.
Single post from Jim Keen-Intellect Rooney - 2010/10/20 18:44:20 UTC. Zilch substance, weak support for the Establishment. Can't say much more 'cause the Establishment isn't gonna come out smelling all that good on this one.
Not all Americans. Mike Lake - 2010/10/26 18:44:20 UTC - does some damage. And Sergey Kataev - 2010/10/28 17:09:33 UTC - gives another plea for the Kaluzhin release which will again fall on totally corrupt ears.
Almost certainly have the full report archived somewhere. But before now the only site at which it was publicly accessible was this UTC-minus-four one.
Nope. 2010/10/20 02:27:23 UTC. That's obviously their source.
That's a copy of this report on Peter's cult rag. ZERO discussion.
But Peter graces us here with a whole twelve sentence post - 2010/10/28 13:44:28 UTC. Uses it to self promote, whitewash Donnell, piss all over the dead guy.
Past Kite Strings ally Gregg Ludwig does nine posts which appropriately blast what Donnell was passing off as instruction.
And note that Donnell is quoted four times, all through Davis, at least half of those being through direct email communications.
- Davis is a total piece o' shit - always has been, always will be. Fuck anybody who dignifies him with the role of dissemination of any information worth reading.
- Donnell doesn't there or anywhere else ever open himself up to the dangers of discussion participation. He majorly screwed the pooch on this one - as he had for everything else he'd ever done in the sport - and he can't afford any degree or flavor of interaction.
Donnell's finished. He has this guy's blood on his hands and knows it. And he also knows that the more and more honestly he discusses it the greater the chances of him getting sued out of existence are. (Lemmy was a lawyer - by the way.) His Skyting Bridle has never worked as advertised, nobody's using it, and hundreds of thousands of aerotow launches have been executed with one-to-one bridles just fine. All his fucking Infallible Weak Links do is stall and crash gliders left and right - just as rope breaks and premature releases were doing in 1974 - and Lemmy's fatal impact is two days shy of the Standard Aerotow Weak Link inconvenience that gets Pete Lehmann's knee sanded down to the bone and forces Russell to command everyone to double up. And now Donnell's been disappeared by The Industry from the history books.
I hadn't remembered that discussion and I don't know if I'd ever understood that it was a foot launch. But at some point I'd painted a vague picture in my head of it having been a platform. And our Russian buddy may have been / be operating on the same assumption. He posts:
I can't tell from the translation whether he posts it as an example of what they WERE or as an example of what they SHOULD HAVE BBEN doing. Maybe Aleksey can help us out.
It's posted by easily reachable Linknife junkie Miller Stroud. If you watch the first thirty and last sixty seconds you won't have missed much - although at 4:08 a helium balloon is released apparently as the glider comes off tow and turns back downwind. No idea what that was about.
Amongst those getting thanks (probably from Jim Seaton) at the end is Butch Pritchett who was a Skyting Newsletter participant and is a total piece o' shit.
And I'm glad I told him he was - just before Davis started rescuing his pet douchebags by cutting my wire.
I need to give that Lemmy Lopez thread a good working over. That crash was a MAJOR game changer in the world history of the sport, we now have another nine years worth of historical perspective, and I'm a lot better at spotting all the crap that's not being said and identifying the motherfuckers who aren't saying it.
Police are investigating the death of an Hidalgo County lawyer killed while hang gliding in Edinburg. Lemuel Lopez died along the stretch of Constitution Street and Highway 281 Wednesday evening. Police say he was in a hang glider being pulled by a pick-up truck.
Lemuel had been learning from Donnell Hewitt and was likely flying a Wills Wing Falcon.
Donnell Hewett writes:
Lemuel Lopez was a wonderful person with an adventurous spirit who took six hang gliding lessons from me and logged some thirty flights totaling about ten minutes in nine months. He was progressing well with consistently good take-offs, climb outs, straight flights, releases, and landings. He was also progressing well in ground school and was well aware of the risks of trying to tow on his own. Therefore, I was shocked to learn that he had built himself a towing system and was killed while using it to tow in Edinburg (some 100 miles away from me in Kingsville).
I have filed an accident report to USHPA and am continuing to investigate what happened. So far I have learned that he was towing with his own unproven towing system accompanied only by an inexperienced driver. He foot-launched successfully and climbed to an altitude of about 100 ft on a 250 ft towline. When the driver could no longer see the pilot in the rear view mirror, the driver stopped and may even have backed up somewhat before getting out of the pickup to watch the flight. The pilot apparently tried to release without success by cutting his weak link with a pocket knife. He continued to fly straight ahead with the towline draped over the control bar still attached to the pickup. When the towline tightened, the glider nosed down and the pilot crashed head first into the ground. He was killed on impact.
As stated previously, I am continuing to investigate the incident to confirm the above report because I have had no opportunity to interview the only eye witness, namely, the driver who obviously has been distraught over the tragedy.
There is a lot to learn from this accident (and a lot more to find out). The only problem is that we've already learned it many times.
Police are investigating the death of an Hidalgo County lawyer killed while hang gliding in Edinburg.
I'm guessing he was killed immediately after hang gliding in Edinburg.
Lemuel Lopez died along the stretch of Constitution Street and Highway 281 Wednesday evening. Police say he was in a hang glider being pulled by a pick-up truck.
If he was in a hang glider being pulled by a pick-up truck then why the fuck wasn't he platform launching? Who else gets pulled by pickup trucks and foot launches?
Lemuel had been learning from Donnell Hewitt...
Does that spelling of "Hewitt" match the one you have on the next line?
Weaklinks need to be strong enough to not break in circumstances where they would put the pilot in trouble, but weak enough to break to help get the pilot out of worse trouble.
How strong should aerotow weaklinks be?
The lowest figure I've seen is that they should break at 85 kg (187 pounds) of tension. The range discussed at the Worlds was 85-115 kg (187 lbs to 253 lbs).
Donnell Howell mentions (using hookin weight of 100 kg and glider weight of 36 kg):
0.5 G - inexperienced pilot: 68 kg (150 lbs)
1.0 G - experienced pilot: 136 kg (300 lbs)
2.0 G - very experienced aerobatic pilot: 270 kg (600 lbs)
you've got him down as Donnell HOWELL. And do you know any operation that's doing what Donnell Howell advises? Got news for ya... Half a G isn't enough to get the cart up to launch speed. It's also at this time been blatantly illegal under FAA AT regs. Those are numbers he's OBVIOUSLY pulled outta his ass. Zack Marzec was a very experienced pilot flying at a max of 0.8 Gs and still didn't have enough aerobatic experience to keep his glider from whipstalling, tail sliding, and tumbling. And yet right after that one many of us suddenly became happy with Tad-O-Links.
...and was likely flying a Wills Wing Falcon.
Well that's probably the problem right there. Wills Wing doesn't design their gliders to be motorized, tethered, or towed.
Lemuel Lopez was a wonderful person with an adventurous spirit who took six hang gliding lessons from me and logged some thirty flights totaling about ten minutes in nine months.
Wow. Are you sure you were getting the interval times long enough for him to get the adrenalin levels back down to something reasonable?
He was progressing well with consistently good take-offs, climb outs, straight flights, releases, and landings.
- In other words he wasn't learning anything about how to fly a hang glider.
- Good thing you hadn't yet started him down on the CONTROL bar and learning serious roll control. He might've gotten in a lot of trouble pulling that shit at under two hundred feet.
- Did you catch that, people of varying ages? Lemmy had never been proned out before. Find a Hewett product out there to contend otherwise.
- He was progressing well with consistently good releases? Is that a skill? Can you show us some videos of the less than stellar ones he had initially and later ones as he started getting his shit together? Any comment on this:
Have you been teaching releasing skills 'cause for the past thirty years it's been too goddam much trouble to develop a release that doesn't require any more skill to operate than a left turn signal does? Or incorporate someone else's design?
He was also progressing well in ground school...
Did he get Skyting Theory:
Donnell Hewett - 1982/09
In addition to the above mentioned roll and yaw tendancies, there is some sideways force on the pilot due to the body line. This is illustrated below:
As can be seen, this sideways force tends to pull the pilot over to the correct side to make the glider turn naturally in the proper direction.
down OK?
...and was well aware of the risks of trying to tow on his own.
- That without another person to run the winch or drive the truck you'd just stand there all afternoon and dehydrate?
- Was he well aware of the risks of actually towing on his own versus just trying to tow on his own?
- What are they? We get zillions of people mangled and killed at commercial operations with tens of thousands of pulls under their belts. But if somebody strikes out on his own and eats it that's always the major emphasis. And there's virtually no record of the folk who strike out on their own and do fine.
- Ya know what the risks of NOT trying to tow on his own are? He's made six two hundred mile round trips over the course of the past nine months for a total of 38 flights and ten minutes of airtime and gotten up to a hundred feet without having gotten to do any actual flying. At Kitty Hawk Kites I could get people up to around Two level in maybe three consecutive days of lessons.
Therefore, I was shocked to learn that he had built himself a towing system and was killed while using it to tow in Edinburg (some 100 miles away from me in Kingsville).
And why do you think he didn't consult with you AT ALL on this project? He was so fuckin' fed up that he never wanted to speak with you again? I've had instructors and ratings officials like that. Damn near all of them as a matter o' fact. A guy who's gonna build his own system is the kinda guy hang gliding needs more of. And the only thing I've heard about that he screwed up on the system was that it didn't have platform capability. And that was something he was never gonna get from you.
I have filed an accident report to USHPA and am continuing to investigate what happened.
Severe conflict of interest. I remember when I asked Santos the morning after he killed Frank Sauber if he wanted me to go back down to Taylor's to help recover the gear and wreckage he thought for about a second and a half and kindly declined.
So far I have learned that he was towing with his own unproven towing system...
So when you turned it over to the US Board of Surface Towing Standards what serious defects and deficiencies did they find?
...accompanied only by an inexperienced driver.
Which part did she fuck up?
He foot-launched successfully and climbed to an altitude of about 100 ft on a 250 ft towline.
Where'd you get this? In the revision he didn't break 25. If he'd gotten to a hundred he'd have probably been OK.
When the driver could no longer see the pilot in the rear view mirror...
How 'bout the glider? Could she also no longer see the glider in the rear view mirror? Me? I tend to always go for the glider before I start narrowing things down to the pilot.
...the driver...
We know it was "the driver" from the beginning of the sentence. What's wrong with "she"?
...stopped...
If the glider had been climbing she wouldn't have expected to see it in the rear view mirror. So if she stopped it was because she saw, heard, felt something else.
...and may even have backed up somewhat before getting out of the pickup to watch the flight.
She stopped the truck with the glider at a hundred feet, may even have backed up somewhat, and got out to watch the flight?
The pilot...
His name's Lemmy. And he's not a pilot at this point. He's a passenger.
...apparently tried to release without success by cutting his weak link with a pocket knife.
Yeah, he pulled the pocket knife out of his pocket, opened the blade, and started hacking away at the weak link in front of his bridle apex. And fortunately it was still under tension so he could do this while flying the glider with the other hand - on the left control tube.
He continued to fly straight ahead...
...over the parked truck with the driver standing next to it watching his progress...
...with the towline draped over the control bar...
He's flying with a two to one Skyting Bridle with the lower elements routed under the control bar. How does the towline end up getting draped over the control bar?
...still attached to the pickup.
And here I was thinking he was using a winch. What was it tied of to? The trailer hitch?
When the towline tightened, the glider nosed down and the pilot crashed head first into the ground. He was killed on impact.
And definitely not after the rebound.
As stated previously, I am continuing to investigate the incident to confirm the above report...
Good freakin' luck.
...because I have had no opportunity to interview the only eye witness, namely, the driver who obviously has been distraught over the tragedy.
Hope she remembers to thank you for all the great training you gave this guy.
There is a lot to learn from this accident (and a lot more to find out). The only problem is that we've already learned it many times.
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.
How many decades worth of that bullshit did we hafta go through before you total assholes began getting your shit together SLIGHTLY better?
