http://www.hanggliding.org/viewtopic.php?t=30828
Sonora wings plane crash
Larry Howe - 2014/02/25 05:32:53 UTC
I could be wrong, but the amount of fatals involving Dragonflies per Dragonfly flying would have grounded any certified aircraft. Maybe we need to spend a little more time analyzing is this just a bad design aircraft.
http://www.questairforce.com/aero.html
Aerotow FAQ
Weak Link
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.
http://ozreport.com/3.066
Weaklinks
Davis Straub - 1999/06/06
During the US Nationals I wrote a bit about weaklinks and the gag weaklinks that someone tied at Quest Air. A few days after I wrote about them, Bobby Bailey, designer and builder of the Bailey-Moyes Dragon Fly tug, approached me visibly upset about what I and James Freeman had written about weaklinks. He was especially upset that I had written that I had doubled my weaklink after three weaklinks in a row had broken on me.
The problem with strong links (neither Bobby Bailey nor I was aware at the time of the US Nationals that pilots were doing this) is that they endanger the tug pilot. If the hang glider pilot goes into a lock out, and doesn't break the weaklink (because there isn't one), they can stall the tug.
http://ozreport.com/5.126
Flytec Dragonfly
USAFlytec - 2001/07/14
Steve Kroop - Russell Brown - Bob Lane - Jim Prahl - Campbell Bowen
The tail section of the Dragonfly is designed so that it can accept in-line as well as lateral loads. Furthermore the mast extension, which is part of the tow system, is designed to break away in the event of excessive in-line or lateral loads. The force required to cause a breakaway is roughly equivalent to the force required to break the double weaklink used on the tail bridle. More simply put, the mast would break away long before any structural damage to the aircraft would occur.
http://ozreport.com/9.022
Worlds organization critique - a response
Davis Straub - 2005/01/25
Weaklinks are a big issue. The problem is that pilots "learn" to make stronger and stronger weaklinks because they do not want to have a weaklink break when it is dangerous (they are low and out of control) and they are penalized by the meet rules which put them to the back of the launch line after they land. Bill Moyes lost eleven spectra ropes the first two days of the Worlds because the pilots' weaklinks were a lot stronger than the ones at the tug end.
http://ozreport.com/forum/viewtopic.php?t=559
Protow vs. weaklink
Davis Straub - 2005/02/21 10:44:27 UTC
Paris wrote:
At Quest, for solo tows, we use two strands (one loop) of a 130. Lb line on one end of a v-bridle, with the knots "buried" to try to remove them from the equation. You'd think this would allow for nearly 520 lb. Of actual tow force, though I never personally measured it and would guess that it's significantly less than this.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
Jim Rooney - 2008/11/23 19:42:44 UTC
The tug uses 3 strand and so all this talk about using a stronger one is academic.
You don't get to have one that's equal or stronger.
See we've got a system that has an extremely solid track record.
Jim Rooney - 2008/11/23 22:28:30 UTC
If you can find one, more power to you.
Just keep in mind if you do, you need to be weaker than the tug's link... not equal to. You will need to talk it over with any tug pilot that you tow behind. Anything less is unethical. And just as you have the right to refuse a tow from any tugger, they have the right to refuse to tow you... for any reason what so ever.
Jim Rooney - 2008/11/24 18:54:27 UTC
I'm confused. I never said the tug's ass was endangered. That's why we use 3strand at the tug's end. Using 4 strand can rip things off (it's happened). When forces are achieved that do break a 3 strand, your tail gets yanked around very hard, which does have implications as to the flight characteristics and flightpath. AKA, I have no desire to allow you to have the ability to have that effect on me when I tow you... esp near the ground.
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!
Bill Moyes, Bobby Baily, and all the pin bending assholes constituting the Dragonfly industry and culture are total fucking morons. This shit is rotten to from the core. Rip it down, figure out which way is up, start over doing it right.
Or will we continue to look the other way because it's one of the few games in town for towing HG.
You mean the way everybody did after Keavy went down?
How long do you think they'd put up with Super Cubs and Pawnees crashing and killing sailplane tow pilots if they had this rate of fatals?
Conventional aviation...
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/25 04:55:25 UTC
It always amazes to hear know it all pilots arguing with the professional pilots.
I mean seriously, this is our job.
We do more tows in a day than they do in a month (year for most).
We *might* have an idea of how this stuff works.
They *might* do well to listen.
Not that they will, mind you... cuz they *know*.
...isn't controlled by unregulated off the scale stupid little shits like Jim Keen-Intellect Rooney and...
http://ozreport.com/12.081
Weaklinks - the HGFA rules
Davis Straub - 2008/04/22 14:47:00 UTC
Pilots must use weaklinks provided by the meet organizers and in a manner approved by the meet organizers. All weaklinks will be checked and use of inappropriate weaklinks will require the pilot to go to the end of the launch line to change the weaklink.
Weaklinks will consist of a single loop of Cortland 130 lb. Greenspot braided Dacron Tolling line and should be placed at one end of a shoulder bridle.
...Davis Straub.
http://www.hanggliding.org/viewtopic.php?t=14312
Tow Park accidents
Jack Axaopoulos - 2009/11/12 14:49:58 UTC
gasdive,
One of the stated goals of this site is to promote HG. MOST views on this site are NOT from members but from visitors, they have no ignore button.
Having Tad run around every day giving the impression that there is a massive weekly slaughter of pilots at tow parks due to their horribly dangerous devices surely doesnt promote HG. Especially when the safety records are quite excellent.
Like Jim said, theyve gone a decade with no fatalities at their tow park. Pretty damn good I say.
Yet listening to Tad, you would think guys were dying all over the place
He's been nothing but misleading and negative and ignored multiple warnings from me. So He's GONE
Why don't you start running your idiot mouth again - pigfucker?
NMERider - 2014/02/25 06:56:49 UTC
You would have to bring up the trump cards wouldn't you?
I brought this up last night in a conversation with an eye-witness to the crash and it was a sore topic.
Do you know how many pilots have been killed...
Actual PILOTS? Precious few would be my guess.
...flying Wills Wing Sport 2s?
After skimming the LZ, suddenly having the nose go up steeply, turning left, making three spirals, and slamming in? I dunno... Fifteen, maybe twenty tops?
The number might shock you.
Yeah...
http://ozreport.com/forum/viewtopic.php?t=25321
Stop the Stupids at the USHPA BOD meeting
Mark G. Forbes - 2011/09/30 23:21:56 UTC
Here's how it really works:
- Member submits an accident report. Could be the pilot who had the accident, or some other witness.
- Accident report is sent to Tim to maintain legal privilege. Tim reviews the report and determines whether there's significant legal risk associated with it. He may redact certain parts (personally identifiable information, etc.) if in his opinion exposure of that information poses a risk to us. If the report is very risky, he may decide that it can't be shared further, and will notify the ED about it. He may also notify our insurers if he sees a potential for a claim, as is normal practice for any incident where we are aware of such a potential.
- Redacted report goes to the accident review chairs, for incorporation into periodic articles in the magazine. Articles focus on root causes of accidents, not on personal narratives or details.
It probably would. It's not like it was in the old days when we had people like Robert Wills and Doug Hildreth working their asses off to identify and fix systemic problems - instead of a national organization and its lawyer doing the precise opposite.
Maybe Wills Wing should cease production?
Maybe Wills Wing should get off its sleazy ass and get people doing hook-in checks and wheel landings, building releases into their gliders, specifying weak link ratings for their glider models, and cutting off dealerships who tow in flagrant violation of FAA regulations.
Yes, there have been a lot of Dragonfly fatalities. I don't know the answer and won't pretend either.
Rookie mistakes. Just listen to Jim Keen-Intellect Rooney.
But these tugs get a tremendous amount of use and probably abuse.
Combine that with crap engineering and you could have some real serious problems.
They go through a huge number of duty cycles and many get disassembled then reassembled after being trailered long distances.
- That's why we have shit like preflight inspections and maintenance schedules.
- Right. That would explain what happened with Keavy and Mark.
- If that WOULD explain what happened with Keavy and Mark any halfway competent crash investigation would find and report it so.
I think it's just an occupational hazard and it's up to each and every pilot in command whether he or she chooses to operate his or her Dragonfly for commercial tug duty.
Right, Jonathan. It's just simply beyond human capacity to design a tug properly and inspect and maintain it for safe reliable operation. Space Shuttle - sure. On the two occasions when they were fried the issues were known beforehand. Goddam ultralight tug to pull two to five hundred pound hang gliders up to a couple grand? No fuckin' way.
And it's up to each and every hang glider pilot to decide for him or herself whether to be towed up behind one.
I don't. Bobby was too fucking stupid to build the back end for the job it was supposed to do and keep BOTH aircraft safe. But that doesn't have shit to do with the issue at hand.
Come what may.
Mark alive was just another threat to the sport. His death has just triggered a productive conversation and forced Jim...
Jim Rooney - 2011/08/26 08:24:31 UTC
Bobby's a fucking genius when it comes to this shit.
...Keen-Intellect Rooney, Davis...
http://ozreport.com/forum/viewtopic.php?t=24534
It's a wrap
Davis Straub - 2011/07/30 19:51:54 UTC
I'm very happy with the way Quest Air (Bobby Bailey designed) does it now.
...Straub, and Paul...
Paul Tjaden - 2011/07/30 15:33:54 UTC
Quest Air has been involved in perfecting aerotowing for nearly twenty years.
...Tjaden out of it.
We need fatal Dragonfly wrecks like this one 'cause they scare the crap out of these front enders who've taken over the sport - while very happily pissing all over the people who buy their toys for them and finance their flying - and force them to confront the fact that they've got a fundamental problem and don't know what the fuck they're doing or talking about.
