[Bob Kuczewski]

Hey Tad, Zack, Free, and Deltaman,

I flew my first hang gliding aerotow this week (tandem at Wallaby). It was great, so now I'm stoked about learning more about towing. I picked up "Towing Aloft" by Dennis Pagen and Bill Bryden during my visit to Wallaby today. I've only spent a few hours with it, but at least I'm learning some of the terminology. I'll probably be posting questions to this topic as time goes on, and I look forward to any help you all can offer to a former foot-launch flyer.

[Bob Kuczewski]

Well, I've been busy with so much other stuff that I still haven't gotten back to Wallaby yet. But I recently found the Birren Design Linknife page:

http://www.birrendesign.com/LKanimation.html

Here's an animation from that page:

      

birrendesign_com_LKanimation.gif (219.94 KiB) Viewed 6718 times

Any comments?

[TadEareckson]

Yeah.

01. Peter's an idiot.

02. The animation depicts a Hewett Bridle. Anyone using a Hewett Bridle doesn't have a clue regarding the basic physics of hang glider towing (or kite flying).

03. Tell me what the Linknife accomplishes more effectively than the Schweizer releases Dave Broyles and others were incorporating in their tow systems in the early Seventies - without having to cut and replace anything each flight.

Phil Wainwright - 2005/02/27

We've been using Linknives here in Western Australia for many years now for both car and aero-towing. From thousands of tows there have been only a couple of release failures. These have been due to either the release line twisting around the Linknife, or wheat stubble becoming jammed in the "v" of the blades.

04. Probably not a great idea to use it in areas where grass - on the ground in setup, staging, launching, and landing areas and/or in wind and dust devils - may be present.

05. Look at what the animation ISN'T showing. Somebody ask Peter who's flying the glider while he's grabbing and pulling on the lanyard.

Peter Birren - 2008/10/27

Imagine if you will, just coming off the cart and center punching a thermal which takes you instantly straight up while the tug is still on the ground. Know what happens? VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8G). So you pull whatever release you have but the one hand still on the basetube isn't enough to hold the nose down and you pop up and over into an unplanned semi-loop. Been there, done that... at maybe 200 feet agl.

Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"Never take your hands off the bar." - Tom Peghiny

Those guys knew what they were talking about. Peter NEVER will.

"In my opinion, the LINKNIFE is exceptionally brilliant! It is the best release I know about."

Donnell Hewett - Towing pioneer, author of Skyting Criteria, inventor of the concept of towline tension sensing and designer of the Hewett Center-of-Mass bridle.

Gregg Ludwig - 2010/10/28

Here is another report from a student (H-0 (Al Hernandez)) (of Donnell Hewett's) that may shed some light on the methods of instruction used. This student weighs about 250 pounds and was using a glider too small for his first tow over asphalt as reported.

>
28th and 29th I will be up in Kingsville, at the Kleberg County Airport about 8 am. I will be training with the Doc. He will be having lessons there Saturday, depending on weather conditions. Will be towed up with a winch - this will be my first tow. Have just been doing foot launch, will get some airtime in on those days.

-

I had to stand like a post, and not move at all once the truck took off at 25 mph with one foot in front of the other, and I am still standing in the same place leaning back, with the payout feeding me line, and there is a strange feeling, odd feeling to being pulled by the payout.

Then I take the first step to the run, and I am now running 25 mph, I am thinking, oooOOOOH SH#T, hope I don't have to run that far, hoping the HG gets lift so I don't have to run no more... My F-A running down the runway like a rocket. There is no wind, I have the right angle of attack, the HG is up, but still not enough lift for the pilot.

I can't reach my CUT line 'cause I have both hands on the downtubes, and if I let go of the Coke bottle grip I will crash.

I feel like pushing the HG into the air, or jumping up so it can lift, but I do not - that would make my situation worse.

I feel I am about to fall into the asphalt face first and crash, I am at my run limit, and feel I can not take another step. Still the glider is not lifting me.

The winch operator lets go of the pressure of the payout winch, my run comes to a jog, and to a stop. I drop to my knees.
<

Guess there's nothing in the Skyting Criteria about being able to use a Linknife to abort a tow when you in time to prevent slamming into the runway when your legs give out at 25 miles per hour.

Here's how Al was undoubtedly configured by Donnell:

http://www.birrendesign.com/towing_B.html

and what isn't being shown by Peter in the animation. You can maybe see how someone running top speed on the asphalt might have a problem getting to the cut line?

The idea behind any release is to be easy to set up, and not activate until it's needed (not a moment sooner). When it is needed - at the top of tow or in an emergency - it has to work the first time, every time.

But it DOESN'T.

The Linknife does that quite efficiently and works by cutting the weaklink, simple as that.

No Peter, it ISN'T. But that's all the level of complexity that your brain can handle.

07. And how great an idea is it to have the part of the bridle with two thirds of the tension in contact with the basetube? Mightn't the Koch two stage - which everyone and his dog has been using in Europe for this kind of towing for the past quarter century plus - be a much better idea?

A straight base tube is better than a speed bar for static towing. The bridle has less of a chance of locking in on one side of a speed bar. (Just a suggestion)

Yeah Peter, just a suggestion that no one in Europe has absolutely no reason to make or hear.

Note that bridle hang-ups on grips and basetube mounted hardware have locked out, mangled, and killed people.

08. And with a Koch two stage you don't have 35 feet of rope and string flapping around after you've gotten off tow.

In my 1000+ tows, I've had to use my hook knife three times... the first was on a pulley tow when an old 2-string release didn't work. Sure did need that hook knife... and RIGHT NOW! Though it worked fine and I lost the bridle and release, it gave me the inspiration to come up with the Linknife.

09. Wanna tell us about the other two?

10. What's the bridle made of?

The Reel Pilots use the Hewett Center-of-Mass bridle for foot launched static line towing of our hang gliders. It's basically a 2:1 pulley that's arranged thusly...

Main Bridle

The main bridle must be much stronger than the towline to prevent snap-back. Bridle measures 20-24 feet (7+ meters). Material should be a no-stretch line like perlon, spectra, or a particular 900-pound test like I found at a skydiving supply house.

Yeah. A no-stretch line like PERLON. Or, in a pinch, bungee.

11. He's cutting the weak link. What's the purpose of the weak link?

VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8G).

Apparently to blow you off tow when you can't get to your Linknife lanyard in the course of an over-the-top lockout.

And somebody ask Peter how it's possible to experience "VERY high towline forces" with a 0.8 G weak link - the FAA's MINIMUM legal rating for the MAXIMUM certificated operating weight of the glider. (The maximum legal for US sailplanes and hang gliders is 2.0.)

12. How is the Linknife being configured? What happens in an Eric Aasletten scenario (Performance Flying - Page 259, Figure 10-15) when Peter's clever little "Pitch & Lockout Limiter"...

http://www.birrendesign.com/LKOpinions.html

...kicks in?

Peter Birren - 2009/05/09

If you want a truly foolproof release, it's got to be one that eliminates the pilot from the equation with a release that operates automatically.

Sorry Peter, a person on a glider who gets eliminated from the decision making and control equation isn't a pilot. If he's lucky he's a passenger. If not he's an item on the eleven o'clock news.

March 18, 2006 - At the Fall USHGA BOD Meeting, the Linknife received the National Aeronautic Association SAFETY AWARD. What an incredible honor!

12. What an incredible farce.

Summary...

The Linknife itself is halfway clever and I occasionally recommend it to people as quick, cheap, and dirty fixes for shoddy systems. And anybody who comes up with an idea better than a bent pin barrel release deserves at least a couple of Brownie points. But there's a lot more to tow configurations and towing itself than a dependable core mechanism.

P.S. The reason that the Linknife is so widely glorified in hang gliding is because it's something simple enough for virtually all of the idiots who fly these things to fully and and immediately comprehend. And when you allow the idiots who fly these things make critical decisions regarding critical equipment it's all gonna boil down to "Simple - GOOD!!! Complex - BAD"!!!

Scott Wise - 2009/04/13

What some are missing with the K.I.S.S. comments is that the USE of the release must also fit within the Keep It Simple, Stupid principle. But it can be a real trick to make both the mechanism and trigger simple AND easy to use (while not removing your hand from the base tube).

But that's what Peter and the other knuckle draggers who constitute the overwhelming majority of this sport are incapable of ever getting - and doing anything about.

[Bill Cummings]

Tad’s post of a quote from Gregg:



Gregg Ludwig - 2010/10/28

Here is another report from a student (H-0 (Al Hernandez)) (of Donnell Hewett's) that may shed some light on the methods of instruction used. This student weighs about 250 pounds and was using a glider too small for his first tow over asphalt as reported.

>
28th and 29th I will be up in Kingsville, at the Kleberg County Airport about 8 am. I will be training with the Doc. He will be having lessons there Saturday, depending on weather conditions. Will be towed up with a winch - this will be my first tow. Have just been doing foot launch, will get some airtime in on those days.

-

I had to stand like a post, and not move at all once the truck took off at 25 mph with one foot in front of the other, and I am still standing in the same place leaning back, with the payout feeding me line, and there is a strange feeling, odd feeling to being pulled by the payout.

Then I take the first step to the run, and I am now running 25 mph, I am thinking, oooOOOOH SH#T, hope I don't have to run that far, hoping the HG gets lift so I don't have to run no more... My F-A running down the runway like a rocket. There is no wind, I have the right angle of attack, the HG is up, but still not enough lift for the pilot.

I can't reach my CUT line 'cause I have both hands on the downtubes, and if I let go of the Coke bottle grip I will crash.

I feel like pushing the HG into the air, or jumping up so it can lift, but I do not - that would make my situation worse.

I feel I am about to fall into the asphalt face first and crash, I am at my run limit, and feel I can not take another step. Still the glider is not lifting me.

The winch operator lets go of the pressure of the payout winch, my run comes to a jog, and to a stop. I drop to my knees.
<


Guess there's nothing in the Skyting Criteria about being able to use a Linknife to abort a tow when you in time to prevent slamming into the runway when your legs give out at 25 miles per hour.

Here's how Al was undoubtedly configured by Donnell:

http://www.birrendesign.com/towing_B.html

and what isn't being shown by Peter in the animation. You can maybe see how someone running top speed on the asphalt might have a problem getting to the cut line?

The idea behind any release is to be easy to set up, and not activate until it's needed (not a moment sooner). When it is needed - at the top of tow or in an emergency - it has to work the first time, every time.


But it DOESN'T.

The Linknife does that quite efficiently and works by cutting the weaklink, simple as that.


No Peter, it ISN'T. But that's all the level of complexity that your brain can handle.

07. And how great an idea is it to have the part of the bridle with two thirds of the tension in contact with the basetube? Mightn't the Koch two stage - which everyone and his dog has been using in Europe for this kind of towing for the past quarter century plus - be a much better idea?

I don’t think this to be a much better idea for Al’s predicament.

Al's release delemma,

Al, Tad skipped over this and did not go into enough detail. Your predicament would not be addressed by the Koch two stage release.

Maintaining the coke bottle grip on your downtubes would dictate that as part of your pre-launch check list that you unzip the fly on your blue jeans.

Now you would have some means available to activate the Koch release while maintaining you Coke bottle grip on the downtubes.

In cold weather while snowmobile towing never use your tongue to activate the Koch two stage release. (Freezing problem.)
If you do use your tongue the food, for the rest of your life, will taste like a Koch two stage release handle.

I hope this clears up the release problem that you experienced.

[TadEareckson]

Thanks much for the thoughtful and constructive reply. It's only because of discussions like these that we see understanding, procedures, and equipment continually and rapidly evolving up and away from the bloodbath that was hang glider towing thirty years ago.

Great example illustrating just how lucky we all are to have the freedom to participate in and guide the development of safe, responsible, self regulated aviation.

[Bill Cummings]

Al I put up a suggestion for your releasing dilemma in the video section. Go to "Al's dilemma."

[Birren]

Yeah.

01. Peter's an idiot.

Coming from a guy like you, Tad, that's a mighty high compliment.

02. The animation depicts a Hewett Bridle. Anyone using a Hewett Bridle doesn't have a clue regarding the basic physics of hang glider towing (or kite flying).

Guess my thousand-plus static line tows with a Hewett Center-of-Mass 2:1 bridle were only a figment of my imagination.

03. Tell me what the Linknife accomplishes more effectively than the Schweizer releases Dave Broyles and others were incorporating in their tow systems in the early Seventies - without having to cut and replace anything each flight.

A. The Linknife is MUCH lighter so if/when a snap-back happens, it won't put out an eye (ala Michael Robertson).
B. Using a new weaklink for each flight helps assure that it won't break prematurely, as the Reel Pilots experienced in the mid- and late-80's when we used a single weaklink many times.
C. By having the release well in front of the wires, there's nothing to snag, especially if in the middle of a lockout to the side.
D. The best: No tow forces are placed on the Linknife but rather go through it... the more tension there is, the faster it cuts with no additional effort required to release.

Phil Wainwright - 2005/02/27

We've been using Linknives here in Western Australia for many years now for both car and aero-towing. From thousands of tows there have been only a couple of release failures. These have been due to either the release line twisting around the Linknife, or wheat stubble becoming jammed in the "v" of the blades.

Thanks, Phil. More than 200 pilots in Australia have been using the Linknife since it came out. These are the first I've heard of these problems... both easily preventable.

04. Probably not a great idea to use it in areas where grass - on the ground in setup, staging, launching, and landing areas and/or in wind and dust devils - may be present.

05. Look at what the animation ISN'T showing. Somebody ask Peter who's flying the glider while he's grabbing and pulling on the lanyard.

Ya know, my address is all over the place and easily found, but not a single person has asked me anything about this. Wonder why. Could it be 'cuz the process is simpler than "grabbing and pulling on the lanyard"? But to answer you, I'm the one flying and in mostly complete control for the half-second it takes to pull the string.

Peter Birren - 2008/10/27

Imagine if you will, just coming off the cart and center punching a thermal which takes you instantly straight up while the tug is still on the ground. Know what happens? VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8G). So you pull whatever release you have but the one hand still on the basetube isn't enough to hold the nose down and you pop up and over into an unplanned semi-loop. Been there, done that... at maybe 200 feet agl.

This event occurred on one (1) of my 65 aerotow launches. The over-the-top lockout happened because of the short towline; had the line been longer, it would've been a non-issue. Using a short like for aerotow is SOP which is one of the reasons I prefer the long static tow line; there's lots more room for error.

Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"Never take your hands off the bar." - Tom Peghiny

Those guys knew what they were talking about. Peter NEVER will.

Tad, have you never flown no-handed? Have you never adjusted your instruments in flight? Have you never pulled a VG cord? Sheesh.

"In my opinion, the LINKNIFE is exceptionally brilliant! It is the best release I know about."

Donnell Hewett - Towing pioneer, author of Skyting Criteria, inventor of the concept of towline tension sensing and designer of the Hewett Center-of-Mass bridle.
. . .

Guess there's nothing in the Skyting Criteria about being able to use a Linknife to abort a tow when you in time to prevent slamming into the runway when your legs give out at 25 miles per hour.

Wish I'd been there but I wasn't. I missed most of the discussion but unless you're being towed downwind, I find it hard to believe he was moving at 25 -- faster than any human being can run -- and not flying. Maybe there's more to it but I'll save that for later.

Here's how Al was undoubtedly configured by Donnell:

http://www.birrendesign.com/towing_B.html

and what isn't being shown by Peter in the animation. You can maybe see how someone running top speed on the asphalt might have a problem getting to the cut line?

The idea behind any release is to be easy to set up, and not activate until it's needed (not a moment sooner). When it is needed - at the top of tow or in an emergency - it has to work the first time, every time.

But it DOESN'T.

The Linknife does that quite efficiently and works by cutting the weaklink, simple as that.

No Peter, it ISN'T. But that's all the level of complexity that your brain can handle.

How thoughtful of you to include me in this discussion... and not include me at the same time.

07. And how great an idea is it to have the part of the bridle with two thirds of the tension in contact with the basetube? Mightn't the Koch two stage - which everyone and his dog has been using in Europe for this kind of towing for the past quarter century plus - be a much better idea?

Tad, you haven't got a clue what you're talking about. Your total ignorance of the static tow system and how it works is exceeded only by your penchant for making up answers to your own questions without learning from reality.

A straight base tube is better than a speed bar for static towing. The bridle has less of a chance of locking in on one side of a speed bar. (Just a suggestion)

Yeah Peter, just a suggestion that no one in Europe has absolutely no reason to make or hear.

Note that bridle hang-ups on grips and basetube mounted hardware have locked out, mangled, and killed people.

08. And with a Koch two stage you don't have 35 feet of rope and string flapping around after you've gotten off tow.

Make that 22 feet of bridle that takes maybe 30 seconds to wrap up, if need be, while at a safe altitude to do it.

In my 1000+ tows, I've had to use my hook knife three times... the first was on a pulley tow when an old 2-string release didn't work. Sure did need that hook knife... and RIGHT NOW! Though it worked fine and I lost the bridle and release, it gave me the inspiration to come up with the Linknife.

09. Wanna tell us about the other two?

Only if you say "pretty please."

10. What's the bridle made of?

The Reel Pilots use the Hewett Center-of-Mass bridle for foot launched static line towing of our hang gliders. It's basically a 2:1 pulley that's arranged thusly...

Main Bridle

The main bridle must be much stronger than the towline to prevent snap-back. Bridle measures 20-24 feet (7+ meters). Material should be a no-stretch line like perlon, spectra, or a particular 900-pound test like I found at a skydiving supply house.

Yeah. A no-stretch line like PERLON. Or, in a pinch, bungee.

Bungee? Are you still off your meds? Damn straight it should be no-stretch.

11. He's cutting the weak link. What's the purpose of the weak link?

Tad, if you have to ask the question at this point, you have no business taking notes.

VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8G).

Apparently to blow you off tow when you can't get to your Linknife lanyard in the course of an over-the-top lockout.

And somebody ask Peter how it's possible to experience "VERY high towline forces" with a 0.8 G weak link - the FAA's MINIMUM legal rating for the MAXIMUM certificated operating weight of the glider. (The maximum legal for US sailplanes and hang gliders is 2.0.)

I see you are still trying to pawn off on someone else what you can't do yourself. Fuckin' coward... ignorant coward.

12. How is the Linknife being configured? What happens in an Eric Aasletten scenario (Performance Flying - Page 259, Figure 10-15) when Peter's clever little "Pitch & Lockout Limiter"...

http://www.birrendesign.com/LKOpinions.html

...kicks in?

Tad, you ignorant slut, if you read further than your selective snipping reaches to somehow prove a point, you would have read how this works. And, pray tell, what is the title of that page? Could it be "opinion"? as in a thought/idea. Surprising, isn't it, that I've heard from a couple of instructors (both with more credibility in their little fingers than you have in your self-inflated ego) who have been using similar systems for years to prevent hazardous scenarios from happening... and it works. But you'll never consider what actually works, just your own concepts of reality.

Peter Birren - 2009/05/09

If you want a truly foolproof release, it's got to be one that eliminates the pilot from the equation with a release that operates automatically.

Sorry Peter, a person on a glider who gets eliminated from the decision making and control equation isn't a pilot. If he's lucky he's a passenger. If not he's an item on the eleven o'clock news.

March 18, 2006 - At the Fall USHGA BOD Meeting, the Linknife received the National Aeronautic Association SAFETY AWARD. What an incredible honor!

12. What an incredible farce.

Tell that to NASA. Tell that to the 1200 pilots who've used the Linknife. But you won't because you're a coward.

Summary...

The Linknife itself is halfway clever and I occasionally recommend it to people as quick, cheap, and dirty fixes for shoddy systems. And anybody who comes up with an idea better than a bent pin barrel release deserves at least a couple of Brownie points. But there's a lot more to tow configurations and towing itself than a dependable core mechanism.

P.S. The reason that the Linknife is so widely glorified in hang gliding is because it's something simple enough for virtually all of the idiots who fly these things to fully and and immediately comprehend. And when you allow the idiots who fly these things make critical decisions regarding critical equipment it's all gonna boil down to "Simple - GOOD!!! Complex - BAD"!!!

Scott Wise - 2009/04/13

What some are missing with the K.I.S.S. comments is that the USE of the release must also fit within the Keep It Simple, Stupid principle. But it can be a real trick to make both the mechanism and trigger simple AND easy to use (while not removing your hand from the base tube).

But that's what Peter and the other knuckle draggers who constitute the overwhelming majority of this sport are incapable of ever getting - and doing anything about.

Care to threaten me with more gunshots to the head? Asswipe!

Peter Birren
http://www.birrendesign.com/linknife.html

[TadEareckson]

Oops. Missed seeing this one till yesterday. Apologies for not having immediately exploited it to its fullest potential.

Coming from a guy like you, Tad, that's a mighty high compliment.

Doesn't matter from whom it comes. In hang gliding stupidity is a virtue. You're welcome.

Guess my thousand-plus static line tows with a Hewett Center-of-Mass 2:1 bridle were only a figment of my imagination.

1. What's your point?

2. If you had pulled off a thousand-plus static line tows wearing pink bunny slippers would that make static towing with pink bunny slippers a good idea for everyone?

3. How much better do your thousand-plus tows with a Hewett Center-of-Mass 2:1 bridle stack up than the untold millions of no-bridle direct-connect-to-the-Koch-Two-Stage-at-the-chest tows?

A. The Linknife is MUCH lighter so if/when a snap-back happens, it won't put out an eye (ala Michael Robertson).

1. How many eyes were put out by the Schweizer releases Dave Broyles and others were incorporating in their tow systems in the early Seventies? We didn't start getting recoil issues until Donnell came along and figured that nylon parachute cord would make a really great substitute for a controllable tension winch.

2. Mike Robertson was on the back of the boat which was towing someone using some piece o' shitt weak link that wasn't up to the job and UNDOUBTEDLY using polypro for the towline. Whether his piece o' shitt weak link had blown on its own or been cut at the same dangerously inadequate tension by a Linknife the recoil - and results - would've been identical. This is why people who know what the hell their doing use towline and bridles which don't stretch and weak links which don't blow.

B. Using a new weaklink for each flight helps assure that it won't break prematurely...

So does using a one and a half G weak link which either stays with the glider - like mine - or is designed to be dragged - like Tost's. And mine NEVER need to be replaced and, while Tost advises two hundred tows - they really don't either.

...as the Reel Pilots experienced in the mid- and late-80's when we used a single weaklink many times.

So it took y'all four or five years to figure out that that was a bad idea and that there might have been at least SOMETHING to what...

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

...these early guys were saying?

C. By having the release well in front of the wires, there's nothing to snag, especially if in the middle of a lockout to the side.

1. How many lockouts have you heard about in which anything gets anywhere NEAR the wires - let alone snags?

2. Where are all the snags we should be getting over the course of ten zillion two point aerotows in which the top end of the bridle is released from a spinnaker shackle anchored somewhere in the vicinity of the control frame apex?

D. The best: No tow forces are placed on the Linknife but rather go through it... the more tension there is, the faster it cuts with no additional effort required to release.

I can blow six hundred pounds of towline tension with about an eleven pound pull to a keel mounted barrel release - WITHOUT taking my hand off the basetube. I can live with that - thank you very much.

These are the first I've heard of these problems... both easily preventable.

Yeah, they're easily preventable. They're also problems that my stuff and the Koch don't have.

Ya know, my address is all over the place and easily found, but not a single person has asked me anything about this. Wonder why.

'Cause in 1981 Donnell Hewett came along and declared that being able to release with both hands on the basetube was not one of the criteria for a safe tow - that if you really had a problem you should be able to just radio the guy at the other end and he - or his assistant - would take care of the problem for you with a machete. And all the idiots in hang gliding shortly thereafter started buying everything he said hook, line, and sinker. And now none of the idiots who participate in hang gliding believe it's within the capability of human engineering to design a release that works to blow you off tow while maintaining maximum control of the glider.

Steve Kinsley - 1996/05/09

Personal opinion. While I don't know the circumstances of Frank's death and I am not an awesome tow type dude, I think tow releases, all of them, stink on ice. Reason: You need two hands to drive a hang glider. You 'specially need two hands if it starts to turn on tow. If you let go to release, the glider can almost instantly assume a radical attitude. We need a release that is held in the mouth. A clothespin. Open your mouth and you're off.

So now they accept everything that stinks on ice as normal and inevitable and won't even tolerate the idea that anyone can do any better.

Could it be 'cuz the process is simpler than "grabbing and pulling on the lanyard"?

Yeah, it always is - until the shitt really hits the fan.

Doug Hildreth - 1991/06

Good launch, but at about fifty feet the glider nosed up, stalled, and the pilot released by letting go of the basetube with right hand. Glider did a wingover to the left and crashed into a field next to the tow road.

This scenario has been reported numerous times. Obviously, the primary problem is the lack of pilot skill and experience in avoiding low-level, post-launch, nose-high stalls. The emphasis by countless reporters that the pilot lets go of the glider with his right hand to activate the release seems to indicate that we need a better hands-on way to release.

I know, I know, "If they would just do it right. Our current system is really okay." I'm just telling you what's going on in the real world. They are not doing it right and it's up to us to fix the problem.

But the shitt only VERY RARELY hits the fan when somebody's down low enough for it to matter and we can ALWAYS find some way to pin it all on pilot error...

Tried to save the tow when he should've released immediately...
Made NO attempt to release...
Shouldn't have been flying in thermal conditions...
Weak link was WAY too heavy...

...so all of the GOOD pilots can feel OK about continuing to use releases which all stink on ice.

But to answer you, I'm the one flying and in mostly complete control for the half-second it takes to pull the string.

British Hang Gliding and Paragliding Association Technical Manual - 2003/04

On tow the Pilot in Command must have his hand actually on the release at all times. 'Near' the release is not close enough! When you have two hands completely full of locked-out glider, taking one off to go looking for the release guarantees that your situation is going to get worse before it gets better.

Yeah, sure you are, Peter. 'Cept every once in a while things stack up to the point when "mostly" totally sucks and somebody who doesn't have to gets killed.

This event occurred on one (1) of my 65 aerotow launches.

Not bad. Only one and a half percent of the aerotows - in which you actually get airborne - are dice rolls when "mostly" totally sucks and a half second has really spectacular consequences.

And then there's this one:

Peter Birren - 2008/10/27

I know about this type of accident (Davis's) because it happened to me, breaking four ribs and my larynx... and I was aerotowing using a dolly. The shitt happened so fast there was no room for thought much less action. But I wasn't dragged because the weaklink did its job and broke immediately on impact.

So three percent of your aerotows tend to be really good YouTube material. And things tended to be so much more boring - 'cept for the broken downtubes resulting from weak link failures - during the ten seasons I flew with the dickheads running Ridgely.

The over-the-top lockout happened because of the short towline; had the line been longer, it would've been a non-issue.

But the matter of the tug having been in a parcel going up fast while you were way the hell behind it in a parcel going down fast would've made it a non-non-issue.

Using a short like for aerotow is SOP which is one of the reasons I prefer the long static tow line;

Yeah, you're right. The whole aerotowing thing was a dangerous failed experiment - doomed from the very beginning. We should all cut our losses and return to nice, safe, foot launched static surface. Probably oughta outlaw platform as well - just look what happened to John Woiwode 'cause HE was ALSO on a short towline.

And what are all those sailplane people thinking?

...there's lots more room for error.

Sounds like you need as much as you can get.

Tad, have you never flown no-handed?

Not within striking distance of anything much harder than air - and NEVER on tow.

Have you never adjusted your instruments in flight? Have you never pulled a VG cord? Sheesh.

Yeah. Adjust the VG on tow. Now THERE'S a recipe for a memorable day if ever I heard one.

Paul Tjaden - 2008/07/22

The lockout Lauren mentioned was precipitated by my attempt to pull on more VG while on tow. I have done this before but this time the line wouldn't cleat properly and while I was fighting it, I got clobbered and rolled hard right in a split second. There was a very large noise and jerk as the relatively heavy weak link at the tug broke giving me the rope. I recovered quickly from the wing over and flew back to the field to drop the line... I have never had a lockout situation happen so quickly and dramatically and had no chance to release as I have always thought I could do.

And you should probably do it low so the camera people can get really good clips to show at your celebration of life gatherings.

Wish I'd been there but I wasn't. I missed most of the discussion...

You can ask Al Hernandez (DarthVader here) about it - he was the victim.

...but unless you're being towed downwind, I find it hard to believe he was moving at 25 -- faster than any human being can run --

On his own - probably not. When being pulled by a lot of horsepower with a glider partially lifting...

...and not flying. Maybe there's more to it but I'll save that for later.

OK, let's make it fifteen miles an hour and downwind. He wanted and NEEDED to abort the tow by using the RELEASE. He couldn't. But I'm sure you can come up with all kinds of reasons why he shouldn't have been in a situation in which he needed to abort the tow in the first place. And let's not even talk about using a dolly 'cause the Skyting Criteria don't consider rolling launches to have significant enough advantages to be worthy of mention.

The idea behind any release is to be easy to set up...

Yeah.

John Moody - 2004/12/16
Conroe, Texas

What is not normal is to see a factory-made glider that has a built in nose attachment or keel attachment or even the keel release built-in, faired and clean - like a VG system is.

So why does Mr. Reynoldson have to ask where to attach his tow line? ATOS has to know that their gliders are being towed every day. Why does each pilot have to figure it out, one at a time. Why don't the manufacturers sell a TOWING version of their gliders and avoid someone getting it wrong?

You certainly wouldn't want manufacturers build mission critical stuff into the glider that can just be left there they way they do with the VG system and those bozos do with their sailplanes. Easy to set up should be at the ABSOLUTE TOP of ANYONE'S list of priorities for ANY release system.

...and not activate until it's needed (not a moment sooner).

Right. It's the job of the weak link or...

Jim Rooney - 2007/08/01

Whatever's going on back there, I can fix it by giving you the rope.

It's more of this crappy argument that being on tow is somehow safer than being off tow.

...some fu**ing moron at the other end of the string to blow you off tow when you don't need or want or can't afford it to.

How thoughtful of you to include me in this discussion... and not include me at the same time.

You locked me out of skysailingtowing - asshole. But isn't it marvelous that we now have a place to resume two way conversation - where you don't don't have scores of the half-witted zombies in your cult to run interference for you.

Tad, you haven't got a clue what you're talking about.

JohnG - 2009/04/13

Rick,

Not being constructive? There is one person who has put more thought and time into releases than anyone. That person is Tad. He explains the pros and cons to every release out there. I gave you the link to more release information than the average person could ever digest, and I didn't get a thank you. Just you bitching that we aren't being constructive. What more could you want? He has created something that is a solution, but no one is using it... apparently you aren't interested either. So what gives??? What do you want us to tell you? Your concerns echo Tad's concerns, so why not use his system? Every other system out there has known flaws.

Yeah, right.

Your total ignorance of the static tow system...

Skyting Criteria

These are Donnell Hewett's original 12 elements of a good tow system. They are as viable today as they were in the early 80's when he wrote them.

...

02: Constant Tension

The tension in the tow line must remain essentially constant throughout every phase of the towed flight. (Some tension regulation device must be used... +/- 15 pounds during every phase of tow. Settings should reflect a "comfortable" flight and "reasonable" climb rate.)

...and how it works...

1. Yeah, it's so incredibly COMPLICATED. One wonders how ten year old kids ever figure out how to keep kites in the air for more than five or ten seconds without smashing them back into the ground. And just think - all without gauges, tension control mechanisms, elastic strings, weak links, and observers with machetes.

ian9toes - 2009/06/14

I strongly disagree with banning the one guy (Yours Truly) who has the most knowledge about safety issues involving what I believe is the most dangerous part of our sport. I hear someone dies every year from towing.

2. And, by the way... Aerotowing - like most people use out in the REAL world in hang gliding and sailplaning - IS a static tow system.

...is exceeded only by your penchant for making up answers to your own questions without learning from reality.

Well it's just super that you're here then - where you CAN answer my questions and you CAN'T cut my microphone when you and the other skysailingtowing a**holes have shot yourselves in your feet.

A straight base tube is better than a speed bar for static towing. The bridle has less of a chance of locking in on one side of a speed bar.

Well great! Who wants to fly gliders with speed bars anyway? Especially those crappy faired carbon jobs one sees all over the place nowadays?

(Just a suggestion)

04: CM Attachments

The tow line/bridle must be attached as closely (as possible) to the effective center-of-mass of each of the components and must not be allowed to touch any other part of the flying system. (Violations of this produce lockouts, adverse yaw, and other loss of control problems.)

Yeah Peter, just a suggestion that no one in Europe has absolutely any reason to make or hear.

Make that 22 feet of bridle...

Fine. Twenty-two.

...that takes maybe 30 seconds to wrap up, if need be, while at a safe altitude to do it.

http://kitestrings.prophpbb.com/topic16.html

Flappy string V kludge.

In my 1000+ tows, I've had to use my hook knife three times... the first was on a pulley tow when an old 2-string release didn't work.

Why?

Sure did need that hook knife... and RIGHT NOW!

Yeah! And wasn't in just super that you had the time and air to be able to use it! 'Cause there was ABSOLUTELY NO WAY you could have predicted the failure of your old two-string ('cept, perhaps, that it was a two instead of a three-string).

Though it worked fine and I lost the bridle and release, it gave me the inspiration to come up with the Linknife.

I'm glad you came up with the Linknife. But I'm not hearing about a whole lot of problems with three-strings from the Hearne truck towing crowd.

Only if you say "pretty please."

Pretty please.

Bungee? Are you still off your meds?

No, I was being sarcastic.

Damn straight it should be no-stretch.

Then why are you including perlon - which is specifically designed to be the precise and extreme OPPOSITE of no-stretch - on the list?

Tad, if you have to ask the question at this point, you have no business taking notes.

I'm one of about a dozen or so hang and paraglider jockeys on the planet who DOESN'T hafta ask the question. But there seems to be a HUGE degree of controversy about it just about everywhere - as typified by the "discussion" going on on The Davis Show right now.

So how 'bout humoring me.

1. What - in YOUR opinion - is the purpose / are the purposes of the weak link?

2. What's your glider model and size, flying weight, and strength of your weak link in pounds and Gs?

3. Why that particular value?

4. Pretty please.

I see you are still trying to pawn off on someone else what you can't do yourself. Fuckin' coward... ignorant coward.

Don't you DARE call me a coward after hitting me with a lock button - motherfucker.

Now you wanna answer the question?

How is it possible to experience "VERY high towline forces" with a 0.8 G weak link?

Tad, you ignorant slut...

Ignorance and sluttiness - two things which bring bliss. Sorry, I've got massive depression issues just about all the time. Must have me confused with somebody else.

...if you read further than your selective snipping reaches to somehow prove a point, you would have read how this works.

1. I've read the whole can of worms - top to bottom - MANY times.

2. With what misconceptions did I leave my reader with the use of my selective snippings? What did I take out of context or distort?

3. Lemme see if I've got things right...

When the glider is locking out or rocketing up and the "pilot" has a death grip with both hands on the basetube ('cause all the sudden he realizes that flying "in mostly complete control for the half-second it takes to pull the string" is gonna 'cause him to fail the practical) the Pitch and Lockout Limiter will eventually kick in, make the "pilot's" decision for him, cut him loose such that his angle of attack will instantly go from dangerously high to through the ceiling, and drop him like a brick for a while until he either regains enough airspeed to resume flying or slams back into the runway, dies of severe head injury (doing what he loved), and has his ashes scattered on Packsaddle Mountain by family and hang gliding "friends".

Did I miss anything?

The excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden...

Yeah, right. Undoubtedly THE most moronic publications ever written on an aspect of aviation since long before the days of cave paintings.

And, pray tell, what is the title of that page?

Pitch & Lockout Limiter.

Could it be "opinion"?

No, it absolutely could not. The word appears in the URL and three times in the text but in nothing remotely resembling a title.

...as in a thought/idea.

There are lots of OPINIONS, "thoughts", and ideas in hang gliding. But virtually all of them which don't have some kind of foundation or analogy in sailplaning and/or kite flying totally suck.

And ever since 1974 when Richard Johnson wrote:

The greatest dangers are a rope break or a premature release.

and 1990 when Brad Anderson and Eric Aasletten reaffirmed the obvious validity of that statement the idea of a Pitch & Lockout Limiter has totally sucked.

And if I were you - which, due to a high degree of variability within the gene pool, I am, most thankfully not - I would get out on all the douchebag glider forums and in the magazine and make sure everybody hears an advisory about that lunatic idea.

Surprising, isn't it, that I've heard from a couple of instructors...

Care to name them?

...(both with more credibility in their little fingers than you have in your self-inflated ego)...

Oh yeah, I'll bet they have credibility. In this sport all you need for massive credibility is to do things wrong better than anybody else for three or four years at a commercial operation and learn how to absolve yourself of all responsibility when you write up the fatality reports.

...who have been using similar systems for years to prevent hazardous scenarios from happening...

Oh, yeah. That type of strategy sounds like a REAL WINNER. Throw somebody unqualified in conditions he can't handle with a release that he can't get to in an emergency, and hope that it kicks in either when he's so low that just the glider gets wrecked or so high that he can recover from the whipstall - and that nothing bad happens in between. Hard to believe that EVERYONE isn't using a similar system.

...and it works. But you'll never consider what actually works, just your own concepts of reality.

1. So let's have some accounts and/or videos.

2. So what you're saying is that lotsa "pilots" really can't execute - or afford to execute - that trivial little "in mostly complete control for the half-second it takes to pull the string" thing in which you're such a past master (except in aerotowing) and that when Tom Peghiny wrote:

Never take your hands off the bar.

the better part of four decades ago he may actually have been on to something.

Tell that to NASA.

Oh yeah. NASA. You're go-to guys for everything you need to know about hang glider towing.

Tell that to the 1200 pilots who've used the Linknife.

Versus the untold tens of thousands of "pilots" who've used the "industry standard" Bobby Bailey...

Bart Weghorst - 2011/02/25

I've had it once where the pin had bent inside the barrel from excessive tow force. My weaklink was still intact. The tug pilot's weaklink broke so I had the rope. I had to use two hands to get the pin out of the barrel.

No stress because I was high.

...bent pin barrel release?

Sorry Peter, ANYBODY who's managed to ooze his way into a position of authority can tell or sell people any crap he feels like...

If you fail to maintain the correct tow position (centered, with the wheels of the tug on the horizon), the weak link will break before you can get into too much trouble.

...and tens of thousands of the morons who participate in this sport will buy it and eat it up with a spoon.

But you won't because you're a coward.

Don't you DARE call me a coward after hitting me with a lock button - motherfucker.

Care to threaten me with more gunshots to the head?

I don't recall threatening you with any gunshots to the head. And if I WERE so disposed I'd aim for some part of your body containing an organ that you'd actually miss if it were gone. But I don't want you dead. I need you to keep saying stuff that's really easy to dismember and ridicule.

Asswipe!

Oh good, you've descended to my level. I so do look forward to the continuation of this discussion.

[TadEareckson]

Oops. Didn't see the crap over at:

viewtopic.php?f=17&t=649

from you - and Sam - either.

Yeah, Peter, you and Sam should get along JUST FINE. IQs in the extremely low double digits and REALLY good with the lock and ban buttons.

Exactly what US Hawks really needs.

(Care to comment on anything, Bob?)

[Bob Kuczewski]

(Care to comment on anything, Bob?)

All I can do is shake my head for having thought that you could be an asset to this forum. Jack and Davis and all your USHPA "favorites" must be laughing their heads off at me for welcoming you to this forum. I guess they deserve the laugh.

Here's to you Tad!! I don't know if hang gliding got into this mess because of you, but you've certainly earned a place in history for keeping it here. Keep up the good work so Jack, Davis, all the USHPA power mongers can stay on top!!