Weak link question

[Tad Eareckson]

Oops.

Second paragraph of the previous was written with respect to the Danny (or Holly) losing tension at the wrong time scenario. The strain is getting to me.

With respect to the weak link holding to beyond the point of survivability... We've got plenty of examples of those. No need for more volunteer demonstrators.

Shawn,

Yeah, I remember you stating your intention to do that a week after Bill was killed.

Every time we have one of these everybody gets all these brilliant countermeasures ideas they're gonna implement. I salute you for being one of the rare individuals to actually follow through.

Post-Kunio, we beat the total crap out of this issue on the Oz Report Forum:

http://ozreport.com/forum/viewtopic.php?t=13132

and arrived at a pretty good consensus - considering it was all hang glider pilots involved in the conversation. I think it will hold up well over time as the last word on addressing this type of accident.

Synopsis (and inserting a bit of my bias)...

There is a handful of good approaches that will help but some are not universally applicable and one can figure out ways to circumvent most all of them.

Prominently - the Aussie method and the bolt-on suspension which encourages it are good but not appropriate for all environments and situations and can be cheated on.

THE KEY - however - is so simple and effective enough so that none of its practitioners has ever had a consequential incident. It's been in black and white staring at us since the beginning of time.

FOLLOW THE FREAKIN' SOPS AND DO THE GODDAM HOOK-IN CHECK IMMEDIATELY PRIOR TO COMMITMENT.

>
Steve K. Re: Launch procedures
1998/01/12 22:02
chga@idbdnet.com
judymcc@... (Judy McCarty)

Steve Kinsley, who almost launched unhooked once, forwards his thoughts:

"Devising a procedure that is proof against distractions and is appropriate in every situation is difficult. I favor hooking in before moving up to the ramp but I don't think there is a single, best answer. And I suspect any grand schemes to force wire crews or pilots to do things in a particular order will just increase the hassle factor and not affect safety. Let me suggest two things: 1. Do a final dip or back step until you feel the strap tighten as part of picking up the glider to launch. 2. Most importantly, concentrate on what you are doing and refuse to be hurried or distracted."
<

That was a couple more local crowd accidents - half of which were fatal - ago. THIS IS WHAT WE'RE -REQUIRED- TO BE DOING.

The most major thing in Steve's post with which I disagree is what's Most importantly. If you make the final hook-in check an instinctive part of your launch procedure you can withstand a lot of diffusion of concentration, rush, and distraction.

The slightly less major issue I take is that if there is any significant delay after picking up the glider you lift and tug repeatedly as necessary.

We who do this - KNOW - we will never launch unhooked. The procedure is, in fact, tattooed on our brains.

While I do appreciate you contribution and implementation of the orange covering on the suspension and paint on the carabiner...

As Danny alludes, this is of no use to the pilot - only to the crew - IF PRESENT. And the pilot MUST be the focus of this discussion.

I also think that the carabiner itself adds WAY more danger to the equation than the paint on it subtracts. I don't believe you fly in any situations in which quick and easy in and out of the glider is of any benefit. I'd be happier seeing you go bolt-on or speed link.

>
Was it adrenaline? Was it rushing? WHY?
<

No. Again...

He was set up for this fatal plunge by ANYONE and EVERYONE who was involved in his foot launch training and recreational hill and ridge flying who permitted him to launch so much as ONE SINGLE TIME without doing a hook-in check and thus in violation of the USHGA SOPs. It's a pretty good bet that - in fact - he NEVER IN HIS SHORT LIFE did a single hook-in check.

This community - and his Instructors and Observers in particular - have a LOT of blood on their hands.

(You're doing these hook-in checks, right Shawn?)

On that note...

Danny,

I once found myself embarrassed at Ridgely when Sea McKeon asked me to do a hang check while I was on deck. I wasn't terribly embarrassed because I would most assuredly have done a hook-in check prior to committing to launch. Even less of an issue than my trademark failure to buckle helmet.

Anyway...

I appreciate what you're trying to do with these potential victims but I actually think you're helping set them up to get killed - EXACTLY as Hank and Cragin did to Bill. The Road to Hell being paved with good intentions thing.

>
stevek

2005/10/02 02:45:48

When Bob Gillisse got hurt I suggested that OUR LOCAL INSTITUTION OF THE HANG CHECK IS MORE THE PROBLEM THAN THE SOLUTION. I still believe that. It subverts the pilots responsibility to perform a hook-in check. I often do not see pilots doing a hook in check. Why should they? They just did a hang check and they are surrounded by friends who will make sure this box is checked.

But what if there is no hang check and you are used to one?

DO A HOOK IN CHECK. you need a system that you do every time regardless of how many hang checks you have been subjected to that assures you are hooked in.
<

(my emphasis)

I am TOTALLY with him on this. The OPTIONAL hang check IS NOT and CANNOT SUBSTITUTE FOR the MANDATORY hook-in check.

Might I suggest that the next time you catch one of these fallible humans you - instead - ask him to pick up the glider, if it's not already on his shoulders, and lift it as high as he can.

This is a very good approximation of what he would have started feeling about eight feet down the north Pulpit ramp, will scare the crap out of him, and will teach him how to do a hook-in check.

Kevin,

Always very happy to have any input from you which your time allows.

Within the realm of honesty - I LOVE flip-floppers. As much and for similar reasons I do complete idiots. If one is not a flip-flopper one has not learned anything since the age of five. If one is not a complete idiot one is not capable of learning anything beyond the age of five.

Within that same realm of honesty but with some intelligence and competence thrown in (and testosterone siphoned off) I also love disagreement and challenges.

Addressing the rest of your post is gonna take more effort.

>
tow releases
1996/05/09 11:50
chga@lists.air-dc.org
skinsley@DGS.dgsys.com (Steve Kinsley)

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. sk
<

Another nail powerwhacked dead center by sk in excess of a decade prior to this point in time at which the unwashed masses have yet to begin to get their shit together.

Janni found himself in what he considered to be a near lethal situation SOLELY and EXACTLY for the same reason that Tog bent his glider and Bill had the life crushed out of his body. All three of them had too much stuff on their cards.

Tog appears not to be remedial. Bill, for an entirely different reason, is definitely not so. I believe Janni is but it's proving to be a very tough slog.

I disagree with one and a half points of your third paragraph. There IS a blanket solution and, while Rome wasn't built in a day, it's been up and running for a long time but very few people have taken note.

At the Currituck stop of the Dragonfly promo tour - 1991/08/02-04 - we had better, safer releases than most people are using now. I don't believe we had secondaries but the primary was simple and cheap and you didn't have to take your hand off the steering wheel to actuate it.

Yeah, I'm a total control freak.

Let's look at the full range of pilot skill/competence range - you being at the top end of the scale, me at the other.

If you tie one hand behind your back I'm almost always gonna be able to fly better than you can.

I can also kick your ass if I give you a glider with an airspeed of five miles per hour and mine has five or six times that.

Although my past flirtations with bourbon, weed, hash, peyote, acid, heroine, crystal meth, plutonium... (the list goes on and on - I can hardly remember anymore) did absolutely nothing to enhance my reaction time as I was led to believe (street dealers are all liars, kids), I can compensate quite a bit for some of those indiscretions by not having to reach for an actuator.

When I start rolling on a cart there are a whole lotta things I don't have to worry about that other people do.

I don't have to worry about finding, reaching for, and triggering a release actuator, a release failure, a bridle wrap, or an overloaded release mechanism.

If I lose tension it's gonna be for one of two reasons: I wanted to or the tug ran out of gas.

I am as much in control of the situation as one can possibly be and not much - if any - worse off than I am in free flight.

Am I perfectly safe and assured of one hundred percent chance of survival? Do I know for certain that I won't be overwhelmed by something too strong and fast for me to handle?

No, but that's no worse than the cards I can get dealt at landing.

Steve and I have gone through some evolutions of the four-string emergency release since its early days. My version of his concept IS a BITCH to adjust but that's a one time issue and, beyond that, the bugs are gone. There is no good reason not to fly one (or two) point without one or another of a couple of options for a hands free release. If you're interested I'll swap what you have for a free upgrade.

>
If I challenge you its because I harbor skepticism regarding the cause of some of these weak link breaks.
<

The cause of ALL weak link breaks is EXACTLY the same - They were loaded beyond their capacities. Simple.

If, at the time the weak link broke, the glider was not damaged - assuming it was still in the air - the weak link was not too strong. Also simple.

If the weak link broke when you didn't want it to - It was understrength. PERIOD. Addendum - it was almost certainly dangerously so.

It must be thought of almost exactly as one does a parachute.

It should come into play at about the same frequency and only AFTER the situation has gone to total hell and not WHILE it's salvageable and it can NEVER be counted on to do any good down low.

>
I have my own snobbish tendencies and when I go out to fly I can't help but silently criticize what appears to be pilots getting by with just enough proficiency and equipment to pull it off.
<

Totally on board with that. I don't think it clouds anything. Quite the contrary. Clear as a bell.

>
Instead of trying to shout over each other to champion our own safety vendetta, lets champion our vendetta's while promoting the other's. While promoting the weaklink discussion, address pilot skill, and when I push for raising the bar on skills, it will include pushing for appropriate evolutions in equipment.

Deal?
<

We don't have "our own safety vendettas". They've always been one in the same. The skills are totally useless without the equipment and the equipment is totally useless without the skills. Lately I've been doing a lot of emphasizing that it is a useless and deadly strategy to attempt to use a weak link as a substitute and compensation for inadequate skills (and equipment).

No deal necessary - we're on the same page.

Now let's team up and beat the crap out of Janni.

[RedBaron]

Another example where an understrength weak link would have been desirable...
http://www.youtube.com/watch?v=F_n5B3-MIC4

[Tad Eareckson]

Janni,

Definitely.

That guy shoulda been using a 0.1 G weak link. This is also the rating that should be mandatory for anyone who believes that a weak link can keep him out of trouble by compensating for incompetence. If he uses one such he'll be right.

Kevin,

Feel free to step in any time. I believe this falls solidly under the jurisdiction of your vendetta specialty.

[Flying Lobster]

Today's word is "intransigent."

marc

[Tad Eareckson]

>
Brian,

Thanks much for giving Janni the reality check. It so helps when it's also coming from a source other than me. You got him upset - which means you've got him thinking.

He's a smart guy - he'll get it sooner or later.
<

Lessee... forty words, five mistakes. Quite possibly a new Guinness record for non political speech.

Well - as Brian expressed last spring - I've always been a lot better understanding and developing gizmos than I have people.

I always like to give logic and understanding as much of a chance as possible but maybe we need to look at the way the grownups play.

In the real world the FAA says, "Get it right way or you don't fly - we'll shred your ticket."

-
USHPA SOP 12-02.10

USHPA Hang Gliding Aerotow Ratings

B. USHPA Aero Vehicle Requirements

6. A release must be placed at the hang glider end of the tow line WITHIN EASY REACH OF THE PILOT. This release shall be OPERATIONAL WITH zero tow line force UP TO TWICE THE RATED BREAKING STRENGTH OF THE WEAK LINK.
-

Janni's primary release came nowhere near to being compliant with the accessibility requirement and his is secondary release(s) was (were) a joke with respect to capacity.

-
C. Aerotow Special Skill Endorsement (AT)

The aerotow skill is a demonstration of the pilot's ability to launch and tow successfully and safely behind a flying tow vehicle. ... In order to receive the endorsement, a pilot must demonstrate the following to an Aerotow Official:

2. ...a complete discussion of all those factors which are particular to the specific aero tow system used and those factors which are relevant to aero towing in general.
-

-
Donnell Hewett

It is impossible to design a weaklink to release the pilot when he loses flight control because there is no correlation between towline tension and flight control.
-

>
Janni

Luckily, my tea bag weak link doesn't hold that long.
<

-
Donnell Hewett

I am sure you can imagine more than one situation where getting off line is the worst possible alternative you can take. In such cases, the towline becomes a "lifeline" rather than a "death-line".
-

-
Danny Brotto

...if the weak link had broken, the downwind wing would have further stalled and I would have cartwheeled into terra firma...
_

>
Janni

They can't be weak enough in my humble opinion...

Quote:
The weak link that saved his butt in that situation is the same one that's gonna break his freakin' neck in Danny's or Bob's.

No it won't, because it's so wonderfully understrength.
<

(Note: BECAUSE IT'S SO WONDERFULLY -UNDERSTRENGTH-?!?!?!!!!)

-
2. (continued...) Must demonstrate complete understanding of ... emergency procedures ... and the indications of an impending emergency and convince the instructor of his ability to execute emergency procedures.
-

>
I probably wouldn't have released ... Because I thought I was in control until it broke...
<

-
4. Demonstrates successful, confident, controlled launches and flight under tow to release at altitude, with a smooth transition to flying, with proper directional and pitch control resulting in proper tracking of the aero tow vehicle in both straight and turning flight and appropriate maintenance of proper tow line tension and airspeed. Should demonstrate the ability to control the glider position relative to the aero tow vehicle. Such demonstrations should be made in typical soaring conditions. A minimum of 5 such successful demonstrations must be made.
-

I came off the cart crooked in my Litespeed, over-controlled and would have quickly been in a close-to-ground neck-breaking lockout if... (he hadn't lucked out after - through no fault of Mother Nature's nor anyone but his own - he commits, in the course of his very short short dolly launch career, what is - to my knowledge - the most dangerous launch in the forty thousand flight / ten season history of Ridgely aerotowing).

So Janni,

Given the above and the fact that you don't even have - or come anywhere close to qualifying for - an AT signoff, what makes you think that you're qualified to enough to contradict and ignore the points of people like Donnell Hewett (who was getting his doctorate in the physics of hang glider towing well before you had figured out how to make and launch paper airplanes in early primary school), high volume commercial tow operators, and lotsa top guns in the competition arena?

[RedBaron]

I'm so sorry Tad. I didn't realize this discussion and your weak links were only intended for pilots with expert aerotow skills. You're right, of course, if one is that good one can fly with stronger weak links. What the hack, perhaps pilots of your caliber don't need one at all on your end of the tow line. It's just that for every situation speaking in favor of stronger weak links I can easily think of a counter-example where an understrength weak link is preferable. A tow line can be a lifeline, it can also be a deathline, I'd give that a 50/50 distribution.
Whatever I choose, I will never be 100% safe. That's why I couldn't care less about your weak links.

[Tad Eareckson]

Janni,

What, exactly, do you mean by "MY" weak links?

In eight of the ten seasons of Ridgely operation Karen has been flying a weak link 1.6 times as strong as mine - with much more success and safety margin than yours truly. Only in the past two seasons have I been flying a weak link fifteen percent stronger than hers.

So let's give credit where credit is due. These are MUCH more KAREN'S weak links than they are mine.

Who said anything about "EXPERT" aerotow skills?

I was referencing the absolute MINIMUM aerotow skills - and, much more importantly, UNDERSTANDING - that are required for a goddam Hang II to get his ticket.

Having "expert" aerotow skills is EXACTLY like having and expert tic-tac-toe playing skills. There isn't much to it, it doesn't take much in the way of brains, you can only get so good at it, and it gets REAL boring REAL fast.

I'm not particularly worried about your SKILLS - although I think they were alarmingly poor at the time of this incident. They're probably at least adequate now and for all I know you will tie or eclipse me on your next flight.

I am, however, extremely concerned about your crappy noncompliant equipment and your abysmal lack of compliance with USHPA SOP 12-02.10:C:2.

You could do a reasonable job of bringing your equipment up to snuff by mounting your brake lever on your basetube - like Matthew did - and swapping out those bent pins with which everyone is so enamored with some good ones. Just doing the former would bring your safety margin WAY up.

But right now your understanding of the principles of an aerotow system and emergency procedures REALLY SUCKS - possibly almost as much as just about everyone else's.

I'd like to see you understand that AT pilots of just about ANY caliber can tow without weak links as safely as they can fly without parachutes.

>
A tow line can be a lifeline, it can also be a deathline, I'd give that a 50/50 distribution.
<

I AM REALLY REALLY HAPPY TO -FINALLY- HEAR YOU ACKNOWLEDGE THAT. We now stand a chance of making progress.

Let's look at the 50/50 part of that statement...

I know of only four relevant incidents at Ridgely - one more than has been referenced in this discussion.

I watched John Dullahan launch on Runway 120 while Bruce was predicting what would happen. John (according to Bruce who was standing next to me) reported that John was trying to use weight shift to correct the cart heading (instead of just staying centered and letting the cart and tow line take care of things automatically).

As soon as he separated he found himself in a really spectacular and prolonged lockout to the right.

It wasn't scary looking though 'cause he was climbing the whole time. His weak link DIDN'T BREAK and he eventually released and had plenty of time to put an uneventful landing together.

We have yours which was entirely self inflicted.

We have Danny's which was partially self inflicted - pitch trimmed too high on the cart, moderate 90 cross.

And we have Bob Koshmaryk's. It could be argued that his was, to some extent, avoidable but I would be quick to say that anyone trying would be full o' shit. That's the one in forty thousand tow that could happen to ANY of us.

So John's was pretty much irrelevant. Totally self inflicted, not dangerous, weak link didn't need to break, weak link didn't break, pilot released at leisure and altitude.

Yours. Totally self inflicted, extremely dangerous, no recognition of seriousness of situation, lucky break. Lucky break not apt to be repeatable for a sustained series.

Danny's. More or less self inflicted but a scenario which can result solely as an Act of God nevertheless. Consequence of losing lifeline potentially lethal. Gained control of situation and flew away unscathed.

Bob's. Pure Act of God and validation of Danny's situation. Gained control of situation, released, and landed unscathed.

So I'm seeing this as more of 0/100 distribution.

>
Whatever I choose, I will never be 100% safe.
<

Maybe. But I think ALL of us CAN and SHOULD be 99.999 or better percent safe. But not if we lack the skills to exercise maximum control of the situation or allow ourselves to be robbed of the ability to do so by a roll of the dice.

>
That's why I couldn't care less about your weak links.
<

I got a little momentum going with the Tow Committee so, with a lot more work and a little bit o' luck I just might be able to MAKE you care.

But don't lose any sleep - nobody every actually enforces safety rules in this bullshit culture anyway.

[Tad Eareckson]

(Make that "ever".)

Oops. Missed a really obvious tic-tac-toe analogy...

The ONLY way you can lose is to do something REALLY STUPID.

And if you've got a downtube mounted release actuator and a weak link under 1.0 Gs you've already more than fulfilled the requirement.

P.S. Note that the two guys who lived because their weak links held were both lightweights - Danny's already given us his stats and Bob's a skinny high school kid.

[XCanytime]

Hey Janni,
You have a choice that would enable you to be 100% safe (relative to towing). You can choose not to tow. Without being tethered to a tow vehicle it's all on you. No extra variables to worry about. No weak link (strength) to argue about. Disclaimer: This is not a anti-towing message.

Bacil

[hepcat1989]

It stands out better against the black harness. Yeah, I guess I did that because of an accident, but it was something easy to do and it stands out better now......It is, The Pilots Responsibility ! I check others anyway. I don't ever want to see.............
Shawn.

[Danny Brotto]

"I think for the purposes of this drill we oughta min out a Falcon 140 - 42+120=162. Allowable max tow line tension range - 130 to 324 pounds."

Now you are making stuff up. If you are going to use the FAA (and I'm not saying their rules apply to HGing) as a guide, then it's the maximum certificated weight not some made-up 160 lbs + 42 lbs scenario. The published all-up weight of the small F3 is 235 and that's what the 80% and 200% (186 lbs to 480 lbs) should be applied to in a one-size-fit's-all scenario.

If an individual pilot fits the 162 lbs all up scenario, then he/she can use the lower pull break accordingly.

BTW on that video, the weak link does seem to break as the HG pilot begins that second roll-out. What he did to regain control tells me that he had no capability (and he had enough scenario to regain control once off tow.) I suspect that either there was something wrong with glider or he was totally inexperienced at flying such a glider and it got totally away from him.

Danny Brotto

[Flying Lobster]

Hey Janni,
You have a choice that would enable you to be 100% safe (relative to towing). You can choose not to tow. Without being tethered to a tow vehicle it's all on you. No extra variables to worry about. No weak link (strength) to argue about. Disclaimer: This is not a anti-towing message.

Bacil

Of course it is!

marc

[brianvh]

Janni;

"for every situation speaking in favor of stronger weak links I can easily think of a counter-example where an understrength weak link is preferable. A tow line can be a lifeline, it can also be a deathline, I'd give that a 50/50 distribution. "

If you really believe the dangers of a weak and 'strong' link are equal, why use the one that causes the inconvenience of having to trudge your glider back to the tow line more frequently? Scale it up proportional to mass but keep it weaker than the one on the tug end. If you join the happy minority with their fingers on the release you might be more willing to make the change.

Yes, I know I said I wasn't gonna participate anymore, but this was so obvious I couldn't believe others had passed it up.

[Tad Eareckson]

Danny,

No, I'm not making stuff up.

I'm on dialup so I haven't yet dared to download the nine meg Falcon 3 manual so I used the 2005 edition.

The allowable hook-in weight range for the 42 pound Falcon I 140 is listed as 120 to 210 pounds. The minimum is about Karen minus the parachute and Camelbak. This gives us a hook up weight range of 162 to 252 pounds. The top is comfortably over one and a half times the bottom end.

I didn't say anything about using the FAA as a guide. What I said was "for the purposes of this drill".

The FAA isn't terribly concerned nor wants to deal with the range of stuff that goes in a sailplane cockpit - It represents a much smaller percentage of the package than the stuff on a hang glider between the carabiner and basetube.

The USHPA - appropriately - says nothing about the maximum certificated operating weight and is concerned - appropriately - only with the stuff on the cart prior to any given launch.

The FAA model for this glider mandates that Thirsty Karen tows between 1.04 and 3.11 Gs. Her max would be 31 pounds above my mid.

>
I suspect that either there was something wrong with glider...
<

Yeah. Something seriously wrong right between the carabiner and basetube. Look no further. He launched like his was coming off of the back of a truck and that was the high point of his performance.

Kevin,

Did the glider look familiar?

Brian,

Good one. Thanks. Wish I had thought of that.

Hope you'll stick around and help me with a few more such gems.

[RedBaron]

You could do a reasonable job of bringing your equipment up to snuff by mounting your brake lever on your basetube - like Matthew did - and swapping out those bent pins with which everyone is so enamored with some good ones. Just doing the former would bring your safety margin WAY up.

This discussion is not about release mechanism. It's about stronger weak links vs. weaker weak links. Actually, it's about weak links that break vs. no weak links at all as revealed by the following statement

I'd like to see you understand that AT pilots of just about ANY caliber can tow without weak links as safely as they can fly without parachutes.

#1: Pilots generally do not deliberately release in close-to-ground oscillations. They generally hang on to fix the problem, or don't realize they've got a problem until the glider is banked 90 degrees and beyond. An understrength weak link would break before that happens. If you watch the video closely, you will see that the pilot is out of position way before things go sour. I don't care if you think he's incompetent, that's beside the point. With my configuration the weak link would have yielded right there. A good thing.

#2: I believe weak links should protect the pilot as well. Considering a tow line a lifeline is complete hogwash. I think they should reliably snap as soon as you're out of position or start oscillating. One thermal can bank an oscillating and otherwise manageable glider past the point of recovery. A weak link break or deliberate release at that point is too late for you'll hammer in with a lot of speed to boot. Landing in the prop wash of the tug is as likely but safer.

#3: I will next season, provided I get permission, deliberately lock out at 2500' in a gradual way in a series of experiments to see whether my weak link breaks consistently and at what bank angle it would do so. If it allows me to enter a full lockout, I may ask Tad to make me a 0.75 G weak link that breaks at precisely that pull force

[brianvh]

Though theory may say you can go into lockout without breaking the weak link, we all know theory is crap and I applaud your decision to test it. I just know that if it was me, no matter how much I said I wanted to test it I'd get spooked and be pulling the release long before I hit lockout.

You need a damn-the-consequences full throttle test pilot. Maybe Ellis is available?

[Tad Eareckson]

Janni,

An airbag has never been a factor in the safety of one of my (or anyone else's) drives to Ridgely. Had it been disabled my face would look exactly the same as it does now.

(Insert joke of choice here.)

I want it in place at all times but I don't want it going off every time a piece of gravel gets kicked up by a semi and bounces off my license plate. That would make the drive more dangerous.

For non aerobatic flights in the entire history of CHGA/MHGA we have had - to the best of my knowledge - only ONE parachute deployment. It happened because a bulky handle was amended to the deployment bag and caught on the basetube - exactly as the pilot had been warned.

So, within the above context, parachutes haven't made us any safer - quite the contrary in fact.

>
I don't care if you think he's incompetent, that's beside the point.
<

His unquestionable incompetence seems to be blindingly obvious to everyone but you and is ENTIRELY the point.

>
Pilots generally do not deliberately release in close-to-ground oscillations.
<

Under the USHGA Aerotowing and Tug Pilot Guidelines, tug and glider pilots are REQUIRED to release at low altitude if oscillations worsen.

>
They generally hang on to fix the problem, or don't realize they've got a problem until the glider is banked 90 degrees and beyond.
<

Under the Guidelines they are REQUIRED to release at half that bank angle. If they're too dense to realize they have a problem they have no business hooking into a glider at the airport, the Pulpit, or Jockeys Ridge. The Pilot Proficiency Program is in place to prevent them from doing so.

In the case of what I believe is the ONLY low level oscillation incident over to occur at Ridgely the pilot did, in fact, handle the situation perfectly.

--

Donnell Hewett:

2005/02/08 18:30

It is impossible to design a weaklink to release the pilot when he loses flight control because there is no correlation between towline tension and flight control.

James Freeman:

The purpose of a weak link is solely to prevent the tow force from increasing to a point that the glider can be stressed close to or beyond its structural limits.

Stuart Caruk:

Will weaklinks prevent injuries to pilots who have crappy launch skills and get drug across the ground on launch? Will they protect against lockout, or even a vertical lockout if the pilot is dumb enough to have the line come tight going downwind? Nope and Nope. The weaklink protects the equipment to ensure the pilot has something left to fly. It's up to the pilot to decide if they are capable of flying it. Weaklinks don't make better pilots than reserves do, and frankly they are in about the same class.

I think a weak link is essential. Its sole purpose is to ensure that maximum designed tow forces are never exceeded.

Steve Kroop:

A weak link is there to protect the equipment - not the glider pilot. Anyone who believes otherwise is setting himself up for disaster. The pilot actuating his release is the way to save himself.

Danny Brotto

2007/05/16 23:15:19

Weak links are not a secondary release system...

--

These people all know what they're talking about. You don't.

And nobody who makes as statement like:

>
Considering a tow line a lifeline is complete hogwash.
<

has any business owning a card with "AT" stamped on it.

[RedBaron]

It is impossible to design a weaklink to release the pilot when he loses flight control because there is no correlation between towline tension and flight control.

Agreed. Irrelevant, however, since loss of line tension renders any weak link ineffective and is, therefore, of no concern in this discussion.

How about this:
It is possible to enter situations that encompass rapid buildup of towline tension beyond what is normally employed to commence launch,
requiring the pilot to quickly release if loss of flight control is imminent.
It is possible to reach the point of no recovery before the decision to release is made.
It is possible to design a weak link to release the pilot entering situations that encompass a rapid buildup of towline tension beyond what is normally employed to commence launch.

No?

[Tad Eareckson]

>
Agreed. Irrelevant, however, since loss of line tension renders any weak link ineffective and is, therefore, of no concern in this discussion.
<

No, it's not irrelevant. In your previous post you were talking about trying to hit a sweet spot which would protect the pilot. And Donnell's statement encompassed a lot more than loss of tension.

>
It is possible to enter situations that encompass rapid buildup of towline tension beyond what is normally employed to commence launch,
<

Yeah...

>
requiring the pilot to quickly release if loss of flight control is imminent.
<

Yeah...

>
It is possible to reach the point of no recovery before the decision to release is made.
<

Yeah... But now it starts getting a little complicated.

If the pilot is either incompetent or brain dead or, as is the usual such case, some combination of the two the decision to release may be made a couple of weeks later when he regains consciousness. Such is also the case regarding this pilot's decision to correct a roll prior to clearing the slot at Woodstock.

But I know of no Dragonfly dolly launch situations that could have been controlled better and faster by the weak link than the pilot.

>
It is possible to design a weak link to release the pilot entering situations that encompass a rapid buildup of towline tension beyond what is normally employed to commence launch.

No?
<

Yeah, fer sure. BUT...

--

Problem 1

Tow line tension two or three times what is required to get the cart rolling may be the ONLY thing keeping you alive in an oscillation situation - such as Holly's or Bob's.

Problem 2

You can be low and locked out / totally out of control / no way coming back and still wanting to stay on tow for a good while longer. Rob Kells pointed out to me that if you're rolled but CLIMBING it's probably a good idea to stay on line to give you more altitude with which to get back level after you get disconnected for one reason or another.

This was, in fact, EXACTLY what happened in the only incident of low level lockout at Ridgely of which I am aware. John Dullahan waited a LONG time to release and, consequently, had plenty of time and altitude with which to recover.

Problem 3

You can be rolled and have a wing stalled - as was Danny's situation - and dependent upon the lifeline for survival.

Problem 4

You can be low relative to the tug and mushing - as was the Bill and Mike tandem situation - and desperately in need of twice as much tension you're getting. (They didn't.)

Problem 5

For me it takes about a third more tension to get the cart rolling than I'm feeling aloft. That extra forty pounds is plenty enough to lock me (or you) out and hold long enough to preclude your survival. Mike Haas - 2004/06/24.

--

So by trying to hit this totally fictional sweet spot you're throwing away certain survival options in four of these documented scenarios for a dice roll which can only MAYBE be of any value in one and then only if you're not doing your job.

The lighter pilots are flying higher Gs with the one size fits all weak link and thus having fewer problems. They're the serendipitous winners of this game.

Amongst the heavier pilots there's a distinct directly proportional relationship between weak link rating and IQ. Think about joining the club.

[brianvh]

"The lighter pilots are flying higher Gs with the one size fits all weak link and thus having fewer problems. They're the serendipitous winners of this game."

This was what convinced me, though I admit in large part it was because I don't have to do much (I'm around 1 g). If I was around 0.5 g I'd be kicking and screaming to prevent having to make a change. I also admit that if I had a bicycle release instead of a lookout pullstring release, I'd be slow to make the change. It's the same reason I'm not a vegetarian: I tend towards moral indolence.

Yes, there are dangers to increasing the weak length strength, but since I'm concentrating so hard when near the ground and I have my finger literally on the release, I can deal with it faster than the link can. Up high when I'm dozing off it's not quite as critical. Deepfloat points out that once you are definitely in a lockout situation (in this case deliberately induced, and most likely you would have released before this) the weaklink often does tend to break before the pilot panics and releases, but since nobody's making weaker weak links for light pilots, stronger weak links for large pilots are indicated.

Just don't go above what the tug has or you'll get the rope and be unhappy.

[Tad Eareckson]

Bacil,

Appreciate you following a thread which has pretty much zero relevance to your range of flying.

What follows is something I started focusing in on a couple of days prior, but anyway... Thanks for the great segue.

In addition to the nonsense about backup suspension being installed to enhance safety and needing twelve thousand pound locking steel carabiners on eighteen hundred pound gliders we've got a few deadly popular myths in this culture, mostly originating in efforts to reinvent wheels that have been working perfectly well in mainstream aviation for the past century.

Ones that come to mind (which we've recently discussed)...

"Don't even consider rolling in for a landing like everybody else does. If you wanna stay really safe you take your hands off the steering wheel at a critical point in the flight, move them to the downtubes, and whip stall the glider at a precise moment to instantly go from eighteen to zero miles per hour."

"A hang check is mandatory and supersedes the optional hook-in check."

"A weak link is a release mechanism which ensures that the glider doesn't get out of control and keeps the pilot safe."

Here's another one:

"Being off tow is safer than being on."

IT IS - IN FACT - HUNDREDS OF TIMES SAFER TO BE ON TOW THAN OFF!

Stop thinking of the kite as a glider and start thinking of it as a Cessna. The tow line is your engine.

Which is safer? A little plane with water in the fuel lines whose engine abruptly cuts out at random points in the takeoff about one out of ten times or one preflighted and flown by a sane person?

Cessnas can get hit by the same crap we do and get kicked around a bit at takeoff. The procedure for dealing with it is not to immediately and irrevocably kill the engine, come up with a Plan B, start over from scratch, and repeat as necessary.

Granted, the analogy breaks down in the case of a low level non climbing lockout, but the instances of those that have progressed so fast that the weak link can come into play faster than the pilot can react are NONEXISTENT (although it may be within the capability of a really determined pilot to deliberately induce one).

The 250 feet of hollow braid Spectra between Dragonfly and glider is virtually ALWAYS a LIFELINE.

Climbing out is ALWAYS safer than landing.

The tow line - as has been demonstrated locally over tens of thousands of tows - is your best friend. But the typical knee jerk reaction is to malign it as your worst enemy.

The reason for this is that it has emerged from a history (ongoing - to no small extent) in which there was often a lot of crap and incompetence in the vicinity of BOTH ends and it took the rap - coming away with a reputation it didn't deserve and is having a hard time living down.

>
You have a choice that would enable you to be 100% safe (relative to towing). You can choose not to tow. Without being tethered to a tow vehicle it's all on you. No extra variables to worry about.
<

Free launcher or tower - Gravity is the common enemy here. It ultimately deposits you on terra firma - the nasty crap that is the only stuff that can hurt you in this sport.

The primary "worrisome" extra variable with which the tow heads are dealing is thrust - just one more very important weapon against the evil gravity force.

In ridge launching you have several tools for putting daylight between terra firma and yourself.

1. You can develop thrust - a la Flintstone - in the course of getting airborne. But once you have - that tool is history.

2. You have the advantage that - as long as you're pointing the right way - terra firma is receding away from you. The downside of that is that if you get pointed the wrong way - tree, boulder, and Timber Rattler infested terra firma starts closing at an alarming rate.

3. If strong smooth ridge lift is present you can pretty much dispense with the thrust drill and easily and safely climb away from the receding terra firma. The downside of strong smooth ridge lift is that - while you're almost guaranteed to survive the launch - you're also almost guaranteed to die of the ensuing boredom.

4. You can use a thermal cycle as substitute for ridge lift to help clear a slope. The ensuing flight is apt to be a lot more interesting but so might the launch itself.

Comparing/contrasting AT launches...

1. As long as the tug pilot takes an occasional glance at the gas tank - we've got unlimited thrust.

2. The terra firma is flat and thus of no aid in increasing the separation rate but if you get turned it doesn't come back up to smack you in the face. It's all mown grass, there are no trees or boulders, and the snakes tend to be Rat, Racer, Hog-Nosed, and Water (try to avoid the Water if you ever have to make a choice).

3. We don't have the terrain to produce strong smooth ridge lift. In the conditions that produce it however, there are two directions in which the launches get really easy but the ensuing flights are infinitely more abysmal than their mountain counterparts.

4. Thermals are mandatory up high, annoyances during the bulk of the tow, and, while rare and mostly avoidable during launch, potentially very dangerous - but magnitudes less likely and probably no more dangerous than the ones at the ramp and almost always quite manageable with tools available.

So now let's start looking at local anecdotal data...

Ed Reno, Chris Miller, John Coleman, Steve Kinsley, me, Chris McKee, me, Ed Tom, Raean Permenter, Bob Gillisse, me, Marc Fink... Somebody wanna help me out with with ridge launches with bothersome and/or unpleasant consequences? It's been a while.

So what have we got from Ridgely launches? Yeah, they haven't spanned the time but they've pumped through a lot of volume. The ONLY stuff we've got are a skinned knee and a few broken downtubes and ALL of those happened BECAUSE the lifeline was lost BECAUSE of UNDERSTRENGTH weak link breaks.

I can think of about four flights originating from Ridgely that were immediately followed by trips to the hospital and ALL of them happened well after normal releases at altitude.

You lose that lifeline at the critical stage of launch...

You ARE coming down at a pretty much fixed time and location not of your choosing.

You lose airspeed - Your angle of attack suffers greatly.

You lose margin to recover from a stall - tip, partial, or full.

You lose the ability to recover from an oscillation (see Holly Korzilius - 2005/05/29).

>
No weak link (strength) to argue about.
<

The people who have their shit together know there is no argument and dial in right around 1.4 Gs.

>
Anyone who believes otherwise is setting himself up for disaster.
<

Disclaimer: This is not a anti ridge flying message. (And I'm not trying to be smart ass about that.)

[RedBaron]

I think there are dangers to increasing their strength and I think there are dangers to flying with understrength weak links as well. It all depends on what risks you're more comfortable taking.

Being off tow is safer than being on

Sometimes yes, sometimes no.

Stop thinking of the kite as a glider and start thinking of it as a Cessna. The tow line is your engine

Nonsense

Climbing out is ALWAYS safer than landing

What you mean here is staying on tow is always safer than landing (you don't climb in a lockout all that great), and that's nonsense as well.

You can be low relative to the tug and mushing - as was the Bill and Mike tandem situation - and desperately in need of twice as much tension you're getting.

Irrelevant, weak links don't create line tension.

For me it takes about a third more tension to get the cart rolling than I'm feeling aloft. That extra forty pounds is plenty enough to lock me (or you) out and hold long enough to preclude your survival.

Sounds reasonable, it's just not backed by what I've personally experienced. Perhaps I found the sweet spot? I will extensively test that next season.

[Flying Lobster]

To lockout or not to lockout..therein lies the rub,
Perhaps kind sir, thou knowest not what it is, much less hath not experienced it's vile temperament.

marc (having stood on the bridge at Stratford on Avon last week)

[RedBaron]

Fair is foul, and foul is fair.

[jimrooney]

Something to bear in mind... the tug's weaklink is three strand.
For clarity... A normal single loop weaklink would be considered two. A tandem double loop is considered four.
In the tandem setup, the "weaklink" in the system is at the tug end, not the glider.

Ya'll seem to be missing this.
Once you go beyond three strand... you're not using a weaklink. If the weaklink goes, you're getting the rope.
Paul found this out the hard way in Texas.

Theory's wonderful and all, but reality is not forgiving.
Ask yourself... are you willing to bet your life on your theory?
Dress accordingly.

Keep fighting Janni. He'll never listen to you, but it's entertaining to watch
Jim