Watch this history. ('Cause they REALLY don't want you to.)
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://groups.yahoo.com/group/skysailingtowing/message/4606
Weaklinks and aerotowing (ONLY)
Davis Straub - 2005/02/09 06:13:39 UTC
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 in the first two days of the Worlds because the pilot's weaklink was stronger than the plane's weaklink. I had heard that the plane's weaklink was 115-135 pounds. The ones on the Dragonfly were on V-bridles at the end of the V-bridle, and the ones on trikes were on three ring circuses.
End result: A very wide range of possible weak link values here depending on pilot skills and weight.
Competition:
Pilots need to be able to go to the front of the line (if they are ready to launch) if they have a weaklink break. Otherwise you'll have "strong links."
http://ozreport.com/9.011
2005 Worlds
Davis Straub - 2005/01/13
Tom Lanning had four launches, and two broken weaklinks and a broken base tube. He made it just outside the start circle.
http://ozreport.com/12.081
Weaklinks - the HGFA rules
Davis Straub - 2008/04/22 14:47:00 UTC
Here is the requirement from the 2007 Worlds local rules (which I wrote) for weaklinks:
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.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
Jim Rooney - 2008/11/24 05:18:15 UTC
Well, I'm assuming there was some guff about the tug pilot's right of refusal?
Gee, didn't think we'd have to delve into "pilot in command"... I figured that one's pretty well understood in a flying community.
It's quite simple.
The tug is a certified aircraft... the glider is an unpowered ultralight vehicle. The tug pilot is the pilot in command. You are a passenger. You have the same rights and responsibilities as a skydiver.
It's a bitter pill I'm sure, but there you have it.
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.
Jim Rooney - 2011/08/28 10:40:24 UTC
Hi Tormod.
Oh, not at all.
I think what you're picking up on is my lack of willingness to discuss this with people that have already made up their minds.
Sorry for that, but it's just the nature of the beast.
I have no issue with discussing this with people that don't have an agenda.
I get very short with people that do however.
Am I "certain" about anything?
Nope.
However, some things get real obvious when you're doing them all the time. One is that weaklinks do in fact save people's asses.
You're 100% onto it... relying on the skill of the pilot is a numbers game that you'll lose at some point.
I find that so many people do not appreciate how fast and furious lockouts can happen.
They're exponential in nature.
Twice the time doesn't equate to twice the "bad"... it's four times the "bad"... then 16... it gets dramatic fast.
Is a weaklink going to save your ass? Who knows? But it's nice to stack the deck in your favour.
Now flip the argument and you start to see the devil.
A glider can take a whole shitload more force than a weaklink can.
So, if you're of the "sole purpose" cult, then you see no issue with a LOT stronger weaklink.
Well, it won't take long with that system before we've got a lot more dead pilots out there.
So they can stuff their philosophical purity bs... cuz I have no desire to tow someone to their death, no matter how willing they may be.
I'm not playing with this stuff in my head and just dismissing it. There's been a lot that's gone into this system.
I've seen too many people walk the "strong link" road only to find out the reality of things.
Fortunately, they've been unscathed, but there have been a lot of soiled underpants in the process.
I'm happy to discuss this stuff.
But I'm sick to death of arguing about it.
http://ozreport.com/forum/viewtopic.php?t=15716
weak links
Davis Straub - 2009/04/26 22:05:31 UTC
Tad doesn't agree, but the rest of us no doubt do, that we are in a partnership with the tug pilot, and that he needs to be protected also, and therefore our weaklink has to be less than his.
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/31 09:25:57 UTC
Oh how many times I have to hear this stuff.
I've had these exact same arguments for years and years and years.
Nothing about them changes except the new faces spouting them.
It's the same as arguing with the rookie suffering from intermediate syndrome.
They've already made up their mind and only hear that which supports their opinion.
Only later, when we're visiting them in the hospital can they begin to hear what we've told them all along.
Nobody's talking about 130lb weaklinks? (oh please)
Many reasons.
Couple of 'em for ya... they're manufactured, cheap and identifiable.
See, you don't get to hook up to my plane with whatever you please. Not only am I on the other end of that rope... and you have zero say in my safety margins... I have no desire what so ever to have a pilot smashing himself into the earth on my watch. So yeah, if you show up with some non-standard gear, I won't be towing you. Love it or leave it. I don't care.
http://airtribune.com/2019-big-spring-nationals/info/details__info
2019 Big Spring Nationals (pre-Pan-Americans)
http://airtribune.fra1.digitaloceanspaces.com/media/contest/files/2019/07/GTxd6mT4AIn8.pdf
Local Rules
15 - Launch
Weaklinks of 140 and 200 pounds will be available and provided by the organizers. Weaklinks provided by the organizers must be used by the competitors.
...
Pilots who have a premature release below 1000' will be slotted back into the launch cue as soon as possible.
http://airtribune.fra1.digitaloceanspaces.com/media/contest/files/2018/10/31F9RzGy00DU.pdf
Aerotow Check List
Appendix D - Hang Glider Pilot Aerotow Checklist
01. Check that the glider has been pre-flighted.
02. Check cart integrity; adequate air pressure in tires, keel support at proper height,
glider hold down mechanism adjusted properly and wheels are straight.
03. Check that glider is properly seated in cart saddles with wheels on the outside (if applicable) and keel is centered on the support.
04. Perform a hang check.
- a. Check that harness is connected to the glider main and backup hang loops and the carabiner is locked. If using a direct connect harness, check that harness is hooked in to direct connect system inside the sail.
- b. Check proper height above bar.
- c. Check that harness lines are straight, leg loops are connected, chest buckle is connected and parachute pins are in place.
- d. Check that lines are fully retracted especially the pod harness line at the harness boot.
- e. Check that helmet is buckled.
05. Check that the bridle is free of all restrictions and is routed above the basetube.
- a. Check bridle connection to release closure mechanism.
- b. Check bridle line for knots.
- c. Check weak link(s) and replace if necessary.
06. Check glider VG line is set for anticipated tow speed and desired bar pressure and is properly stowed.
07. Check instruments are properly attached to base/downtubes and turned on.
08. Check that all electronics (radio, phone, camera) are on and working properly.
09. Connect tow rope to bridle. Check tow rope clip for proper closure.
10. Signal for "take up slack".
11. Check final line tight configuration of release, bridle, tow rope and clip for routing, knots and assembly/closure.
12. Check tow rope is clear and no knots are visible. 13.Check that wind conditions are suitable for launch. 14.Check for air traffic.
15. Mentally prepare for tow and emergency actions.
16. Say "Go go go!" to start the launch.
REMEMBER, as the pilot of a Hang Glider, YOU are responsible for checking everything! A crew person is only an assistant, and a second pair of eyes. Attention to detail is paramount. Should there be any problem that you did not catch, you must take responsibility for your own safety! Releasing is the only way to abort a tow!
We start out using a double looper on the Dragonfly so it, the tandem glider, and the tow mast all blow at the same time.
At Forbes the Dragonflies are using something a bit LIGHTER than you'd have on a two point solo glider. Still plenty enough towline pressure to pile drive Robin Strid back into the runway ('cause - as we all very well know - the glider Tad-O-Link automatically overrides whatever the tug's using).
But still the PILOTS aren't happy 'cause they don't want their weak links increasing the safety of the towing operation when it's dangerous (they are low and out of control). Go figure.
Then they make the back end weak links so safe that they can't get anybody airborne and keep shuffling their relighters to the front of the line. And if you're caught trying to hook up with a Tad-O-Link you're sent to the back of the line to refit and contemplate how close your selfish action came to killing the tug.
Then we're just passengers behind the motorized Pilots In Command and we need to use weak links to protect the tug's new, improved, unannounced weak link - unless we're tandems. If we're tandems everything's OK. (As long as you're not slope launching and flying - hang or para - with Jim Keen-Intellect Rooney.)
Now...
- We just choose whether we want to fly at 108 or 154 percent of the previous astoundingly long track record max - regardless of glider flavor, flying weight, experience, skill, conditions, what the hell the tug's using. Pick one - 140 or 200. Nothing in the middle. (Which is what we'd do if we were choosing glider square footage.)
- If we pop off we go to the back of the line. (So you'd hafta have a low single digit IQ to go with 140 - on that issue alone.) No bearing on either u$hPa SOPs or FAA AT regs whatsoever.
- WE are the Pilots In Command of OUR gliders. The fuckin' tug driver doesn't have shit to say about our hook-up. (And if the fuckin' tug driver is flying legally he's gotta stay over four hundred pounds on his end.) And we don't hafta tell the fuckin' tug driver shit about our hook-up (so he can properly evaluate and adjust to the equation).
- RELEASING is the only way to abort a tow? Our Infallible Weak Link won't keep us from getting into too much trouble, increase the safety of the towing operation, ensure a safe recovery, help us stack the deck in our favour? We can't just pitch out abruptly and pop our two hundred pound instant hands free release?
That last chunk is absolutely tectonic. It's a virtual total refutation of nearly four decades of Hewett based and Pagen advanced aeronautical snake oil. This has been the biggest scam in aviation history. The Ponzi scheme became toast on the afternoon of 2013/02/02 at Quest and I think that either Davis was paid off to run his newsletter/forum through the shredder or he did it on his own initiative - or maybe a mix.
http://www.hanggliding.org/viewtopic.php?t=32673
This is terrible
Dave Pendzick - 2015/03/30 17:42:41 UTC
This is not going to end well for us...
It didn't. And it wouldn't have after 2005/09/03 Arlan Birkett / Jeremiah Thompson if the family had pursued the legal action they'd started and I'd known and understood then what I know and understand now. The Jack and Davis Shows would've been total gold mines for good attorneys after 2015/03/27 Jean Lake and I'd have been only too happy to guide them through any rough spots.
Still no public reaction outside of Kite Strings and two Jack Show posts.
Yeah, I don't even read all of those long winded "explanations".
. Reminds me that any and all Davis Show origin images, photos embedded here and anywhere else are - or should be - currently toast. But here's Davis getting a much needed and deserved face rearrangement at Finger Lakes:
