I've been using one for nearly two years and consider it the best commercially available release.
Gawd. It's about freakin' time.
It took a little experimentation to get it set up optimally initially, and I think the spring is too heavy, but I see he now offers a lighter spring as an option.
Yeah. I got on him about that about that two months ago. Hopefully he'll remove the stronger spring as an option.
Landing clinics don't help in real world XC flying. I have had the wind do 180 degree 15 mph switches during my final legs. What landing clinic have you ever attended that's going to help? I saved that one by running like a motherfukker. And BTW - It was on large rocks on an ungroomed surface.
Jim Rooney's one-technique-fits-all attitude espoused on the Oz Report Forum has become tiresome to read. It does not work in the fucked-up world of XC landings and weary pilots.
...in narrow dry riverbeds with large rocks strewn all over the place.
GT Manufacturing Inc. (GT) and Lookout Mountain Flight Park Inc. (LMFP) make no claim of serviceability of this tow equipment. There is no product liability insurance covering this gear and we do not warrant this gear as suitable for towing anything.
isn't warranted as suitable for towing ANYTHING - and, if fact...
After several dysfunctions encountered by tandem, using a V-bridle and a 145kg wl on the apex, so a maximum load of 83kg on this primary release, I sent 3 times this email to fly@hanglide.com (LMFP contact) without any answer !!! :
Hello
I recently purchased one of your Aerotow Primary Releases for use in aerotowing tandem gliders. We conduct a tandem aerotowing operation just south of Paris, France.
We have been having considerable trouble releasing when the line is under high tension. It takes considerable effort to pull the Rope-Loop release, often requiring two or three violent tugs on the loop. Obviously, this is a considerable safety concern.
One possible reason for the difficulty is the fact that there is some play in the barrel, which does not fit 100% snugly against the main block. When there is tension on the line, the release catch tilts the barrel very slightly, which may have the effect of increasing friction and causing the barrel to catch (there is very slight burring on the main release block as a result of this tendancy).
I would appreciate any feedback you may have on this problem. If this is not an isolated case, and is in fact a design flaw that you have rectified in subsequent models, I would like to know the procedure for acquiring the updated model. If it is simply a problem with this particular item then I would like to have it replaced.
is NOT suitable for towing ANYTHING.
Zack C - 2011/07/10 00:53:22 UTC
So I took a trip to Lookout last weekend and my release gave me trouble (must be something in the air over there...). I took two tows on two different days and on both I had to pull the actuator loop three times before it released (password = 'red'):
Naturally, the release worked fine on the ground. I brought the release to the shop for 'inspection' (following the manual's instructions...) and the employee there seemed concerned but not surprised...she said they modified the design since I purchased mine (I didn't follow her description of the change but I think she was saying they shortened the required travel distance of the barrel) and would swap my release for a new one at no charge.
I took them up on it...they only had one in stock and without a side-by-side comparison it appears the same to me. Shortly after I got it I noticed the barrel seemed fixed in place short of the pin...it wouldn't budge. The release was coiled into a helix secured by the Velcro straps. I unwound it and found it then functioned as expected, but coiling it again reduced the available travel distance of the barrel. I never noticed behavior like this with other releases and don't understand it but the fact that the curvature of the cable can apparently affect release performance greatly concerns me.
On top of that, after getting back to my glider I found the cable was much longer than my previous one. It looks like it was made for a tandem or something. By this point the shop was closed and I was heading out early the next day, so it looks like I'm just going to have to deal with the excess for now.
And if that wasn't enough, I talked to a pilot from NW Texas that was also visiting and he had problems with the barrel on his release being so close to the edge of the pin that it was releasing prematurely on him a few feet off the ground. Last I spoke with him Matt was working on fixing it.
In fucking spades.
A number of different mechanisms are used... for releasing the V-bridle on a two or three point aerotow system.
Some aerotow releases, including a few models from prominent schools, have had problems releasing under high tensions. You must VERIFY through tests that a release will work for the tensions that could possibly be encountered. You better figure at least three hundred pounds to be modestly confident.
Maybe eight to ten years ago I got several comments from people saying a popular aerotow release (with a bicycle type brake lever) would fail to release at higher tensions. I called and talked to the producer sharing the people's experiences and concerns. I inquired to what tension their releases were tested but he refused to say, just aggressively stated they never had any problems with their releases, they were fine, goodbye, click. Another person tested one and found it started getting really hard to actuate in the range of only eighty to a hundred pounds as I vaguely recall. I noticed they did modify their design but I don't know if they ever really did any engineering tests on it. You should test the release yourself or have someone you trust do it. There is only one aerotow release manufacturer whose product I'd have reasonable confidence in without verifying it myself, the Wallaby release is not it.
Oh yeah. Tiberiu probably wouldn't have started the topic if he were happy with the Industry Standard shit. And I notice there haven't been a whole bunch of Jack Showers singing its praises quite yet.
I also wanted to make this release available to those on a budget without compromising anything in the way of safety and reliability.
Fuck those on a budget. If you spend the same for your release system that you do for your parachute you'll get at least thirty times the safety bang for your buck. Anybody who wants to compromise in this area for the sake of a few hundred dollars has my enthusiastic blessing to leave the gene pool.
And I'm guessing there are a lot of people out there who've flushed over five hundred bucks down the toilet in fruitless "Quests" for an Industry Standard two point that isn't a dangerous total piece of shit.
The relatively low cost of this release is not an indication of poor quality but rather a reflection of my desire as a pilot to build the safest release I could conceive, make it affordable, and therefore put a safer release in the hands of my fellow pilots.
Then you need to specify safe weak links. As abysmal as the Industry Standard crap is it's not the big problem. On only the rarest of everything-lined-up-right circumstances - almost always involving a major and easily avoidable pooch screw by the glider pilot - is an inaccessible and/or inoperable release a consequential issue. The fuckin' Rooney Links are crashing people left and right.
My goal is not to make a large profit but to give something back to the sport which has given me so much joy since I began in 1985.
Sometimes I wish I'd never heard of this goddam idiot sport.
Every release is tested using 150 kg weight before being shipped although destructive tests show that the release can take closer to 200 kg before there is any permanent deformation of the release pin. At this point the release still worked successfully. This much force at the release would translate into an extremely high force at the tow rope due to force reduction at the tow bridle, and proper weak link selection should never allow anywhere near this much force to be applied to the release, but it illustrates that the release is built and tested to high standards and affords a significant safety margin for material strength.
Let's knock 41 pounds off of two hundred kilograms and make it four hundred pounds. And that's a lot because you need a really small diameter line with a really high capacity (that I can't find available any more)...
Four hundred pounds on a two point bridle translates to 696 pounds towline.
696 pounds towline translates to 1.9 Gs on a T2 154. That's still legal and not the least bit ridiculous.
150 kilograms translates to 331 pounds or 576 towline.
576 towline translates to 1.9 Gs on a Sport 2 155 or 1.0 Gs on a Falcon 3 Tandem.
We can probably go to 375 pounds for 1.14 Gs on the tandem without having to worry about the pin - but that's definitely on the anemic side.
There are now two versions of return spring. The normal version has a rather stiff return spring which means that even at zero load it takes a 3 kg pull to activate the release. The light action version only requires about 1 kg pull at no load.
- Lose the heavy spring entirely. Anything over 0.1 kilograms is just degrading performance for no reason whatsoever.
- It doesn't do any good to keep return spring force on the barrel if a fuckin' Rooney Link is gonna dump the glider off tow for no or a really bad reason anyway.
The tow forces are nearly high enough to pop the weak link.
What weak link?
We'll do everything we can to get your releases in the air and Jim Keen-Intellect/Bent-Pin/No-Funky-Shit Rooney out of it but we need to do the whole package. And now that for the first time in the history of mainstream hang glider aerotowing there's a commercially available two point release that can be counted on to be fully operable and functional in any emergency a few people...
Although the release has not been loaded to the destruction point, it has been tested with 150 kg of weight which, with a typical 60 degree V-Bridle setup would represent roughly 258 kg of tow force. Always use a weak link as part of the bridle setup to limit these forces. The release itself is strong enough to transmit destructive forces to the glider...
I doubt it. I suspect if you got a thick enough line to transmit the necessary tension engaged by the pin it would distort the pin pretty fast, start converting it to...
And you're anchoring to the keel - which is what you're anchoring yourself to. The glider - make it a Sport 2 155 - can take at least six Gs which means the keel can handle a 250 pound max hook-in pilot at six Gs or fifteen hundred pounds.
In the absence of a weak link the pin's gonna be the weak link. When the glider's holding fifteen hundred pounds from the keel you'll have half the tow tension going through the bridle and half going through the harness and suspension. The suspension will be pulling 875 and the release anchor 625. I think the pin will be toast. Or Tost - either homonym works.
...which must be prevented through proper weak link selection.
Which is what?
- Ideally we should be protecting the glider.
- One step down we should be making sure the pilot shouldn't hafta pull more than 25 pounds - which is a reasonable generally accepted limit.
- Least desirable we're protecting the release from damage.
According to USHGA guidelines permissible weak link breaking strength is 0.8 to 2.0 times the total weight of glider and pilot combination.
Nope.
- In the 2009/03 SOPs - and for many years prior - the REQUIREMENT was a max of twice flying weight and the other end was as safe as any tug driver shit felt like forcing you up on.
- By 2011/05 Trisa had changed all the REQUIREMENTS to GUIDELINES so any tug driver shit could force you to buy and fly...
Oh, btw... before you go there, cuz it is where you're headed... please note the word "Guidelines".
As I said.
Been through this shit a million freaking times.
Please quit trying to educate me about my job.
...anything he felt like.
- In the 2012/06 version Trisa finally clued us in that FAA was covering under sailplane regs - and had been since 2004/09 - nearly eight years prior. And those regs specify:
-- a MINIMUM - a first in the history of hang glider towing - of 0.8 times max certified operating weight, not actual flying weight
-- a max of twice max certified operating weight
- And five days after Zack Marzec's approximately one G Quest Link dumped him to a fatal rest on the Quest runway Trisa deleted all references to weak link regulations, requirements, guidelines, recommendations.
DO try to stay current - as difficult as that may be.
The duct tape and zip ties have been replace with Velcro.
The INSTALLATION INSTRUCTIONS say:
The release cable should be secured very well to the down tube. A combination of duct tape and cable ties is very effective. Secure the cable with several tight wraps of duct tape at three or four locations along the length of the down tube. Some pilots prefer a section of hockey tape in the area of the down tubes where the glider is normally held during foot launching. Leading the cable beneath these wraps helps secure and hold the cable along the down tube. At the ends of the down tube two cable ties should be added over the duct tape to add strength. A hose clamp at the pilot end is preferred. In any case the attachment must be able to withstand a pull on the lanyard of at least 12 kg which may be required when releasing under high tension.
So when some fuckin' douchebag figures the success with velcro on this configuration should be just a good as the success we've all heard about with velcro on Quallaby Release levers...
When Jim got me locked out to the right, I couldn't keep the pitch of the glider with one hand for more than a second (the pressure was a zillion pounds, more or less), but the F'ing release slid around when I tried to hit it.
...he's not using Joe's release any more than some asshole who figures a cardboard tube will make a perfectly acceptable replacement downtube for a Sport 2 155 is flying a Wills Wing certified glider. Either substitution has the potential to kill the self appointed engineer or one of his beneficiaries equally dead.
The Monkey fist with a large washer.
Joe didn't advise that. But go right ahead - use a large washer. I can use the laughs when some Darwin case piles in and gets a finger or two half ripped off.
The point of his release is that there is a consistent small amount of force (due to the spring) required to release the V-bridle, irrespective of the pressure from the V-bridle.
I like the bent gate bar, as Marc suggested that should make release force many times less than tow force, if not nearly independant of tow line force.
Nicely done Lookout! Elegant solution!
As in most cases, the simplest designs work best.
...as usual. Meanwhile, back at reality...
Typical force with a good setup is 10 kg on the lanyard to release 150 kg of load applied at the release pin.
The only two releases which blow at actuation efforts independent of towline tension are Peter Birren's Linknife - which actually gets easier with tension - and my bungee actuated system:
Ya know... Virtually all hang glider aerotowing in the world is being done - for all intents and purposes - without glider releases (outside of Russia / Eastern Europe anyway).
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.
They're damn near all inaccessible, poorly or, more often, NOT engineered, and highly malfunction, lock, jam, wrap prone.
But since pretty much the only time a good aerotow release can be important is in a low level lockout and low level lockouts are:
- extremely rare
- easily avoidable
- seldom survivable regardless of:
-- equipment
-- skill and reactions of the people on both ends of the string
if you took away everyone's releases, just tied bridles to shoulder straps and keel attachments, and made sure everyone had a hook knife to use at wave-off at two thousand feet you wouldn't see an increase in serious crashes, injuries, and fatalities.
I'd predict you'd actually see a DECREASE in serious crashes, injuries, and fatalities because there'd be no temptation for people to reach for anything and they'd be in better shape when their Rooney Links finally got around to blowing or their tug drivers finally got around to making good decisions in the interest of their safety.
I'd predict that if you just tied bridles on, eliminated all weak links from the back end, and put the double loop of 130 pound Greenspot back on the Dragonfly - the way things were before the Dragonfly douchebags decided to start protecting their tow mast breakaways - that aerotowing crash rates would PLUMMET.
That's not to say that it's not totally moronic and irresponsible to fail to equip yourself with the best system obtainable because:
- people make mistakes; and
- shit happens (even though it shouldn't)
and every once in a while a few extra degrees of roll, a fraction of a second delay, and/or five or ten fewer feet of altitude can make the difference between someone coming out smelling like a rose and dying doing what he loved. But don't expect to:
- find yourself in a situation in which your investment will pay for itself
- survive a situation in which your investment could be a factor
You have a greater mechanical advantage by being at the end of a longer moment arm like when you are using the control bar instead of holding on to the downtubes. It takes less effort to make a control input that way.
The pin of a straight pin barrel release has a greater mechanical advantage by being captured at the end of a longer moment arm verses a curved pin design.
And one would think that even brain dead glider drivers would be able to figure out that controlling a glider from the control tube affords greater control and that even BDGD's could view a photo of a straight pin barrel release and conclude that it takes less effort to release that way.
Yeah, but in hang gliding the length of the track record is WAY more important than the length of the moment arm. And the straight pin barrel release has an EXTREMELY short track record.
On http://www.nanoavionic.com/ you can see my new variant which has low actuation force. If you like I can send you the new spring. You can pull the big spring off with strong pliers or vise grips. The new spring you can install on the cable by starting at one end and turning the spring like a screw. Actuation force at no load is about 1kg and with 150kg load about 6kg to pull.
I was towing and I'd attached the link to the towline incorrectly.
- Yep...
(And I know that I shouldn't be rubbing anything in at this point, but... Ferchrisake.)
- How 'bout referring to that thing as a RELEASE rather than a LINK. Despite what you may have read and/or been taught those are NOT interchangeable terms.
- So I guess it's not normally all that important to have a launch assistant checking things out before the winch starts cranking.
- You'd have had to have gotten REAL creative to figure out how to totally disable...
Yeah. You reduced a perfectly good three-string to the level of the New and Improved two point Lockout Mountain Flight Park Aerotow Release or the Weghorst bent pin barrel release.
At a thousand feet I realized I was in trouble, couldn't fix it, was descending at three thousand feet per minute, and tossed my parachute.
HANG GLIDING FOR BEGINNER PILOTS
By Peter Cheney
Published by Matt Taber
Official Flight Training Manual of the U. S. Hang Gliding Association
Towing equipment
- Weak link: The weak link is a specially-calibrated piece of line that is placed at the end of the tow line - if the line tension gets too high for any reason, the weak link will break and release you from tow.
- Hook knife: A hook knife is a razor-sharp cutting tool that can slash through lines in an instant. You should never tow without one - in an emergency, you can use it to cut the tow-line or bridle. The hook knife must be mounted on your harness so that you can reach it quickly and easily.
Weak link in truck towing WILL (read: should) still break in a lockout situation... but as everyone has already pointed out, it takes a lot longer because the glider can continue to pull line off the winch.
There is a limit to how fast line can come off the winch though... so the forces still build up, and the weaklink still fails.
Eleven seconds after my parachute was full I was on the ground. More excitement than I need, I can assure you.
Vimeo is much better video quality. At 1:09 in I release my auto-release.
You mean the mechanism that very clearly provides you protection from an excessive angle of attack for that form of towing?
I guess if you don't have a release that allows you to blow tow with both hands on the basetube something like that can be counted on to fix whatever's going on out there.
That allows me to get somewhat higher without it disconnecting the tow.
Why the fuck isn't Pat using a goddam Koch two stage?
At 1:24 you can see me try to release the tow and nothing happens, even after several tries.
- Well, at least you were able to try - which you wouldn't have been in a low level lockout.
- What if you had at least had a pair of barrel releases on your hips instead of a three-string at the apex?
By 1:30 in I know I'm in trouble.
- You were in trouble at 0:02 when you stamped your foot to signal your idiot fuckin' driver that you were hooked in, had your leg loops, and were ready to go.
- If you can't be bothered to use a fucking hook-in check to signal your driver would you consider using a fucking launch dolly?
I kicked my feet out of the harness to indicate that I had a problem.
- And what was the emergency procedure in place to respond to that signal?
- How 'bout considering lifting your fucking glider up to the stops twice just prior to launch to indicate to yourself, driver, and everyone watching you that there are two particular problems that you DON'T have.
(But they already knew that.)
- Oh, yeah. Panic.
- THEY? Mission had the luxury of having more than one person stationed at the winch but couldn't be bothered to have a single launch assistant at the other end of the line?
By 1:40 you can see the towline, nearly straight down, over the base tube starting to put pressure to dive.
Why the fuck:
- isn't Pat using a goddam Koch two stage?
- is that line still under tension?
By 1:50 I start fishing with one hand for my parachute. That didn't work.
DUDE! That's the THIRD THING that hasn't worked so far this afternoon. Who'da thunk!
At 2:00 I begin to use both hands and at 2:10 the parachute is finally out.
Would've been a good idea to throw it aft between the tail wires.
The video shows that 'chute waving around but it's still. The glider and I are doing the waving. That's obvious if you see the shadows on the glider wing. At 2:19 you can see the glider shudder. That's the towline being cut on the hose clamp that holds the wheel in place.
- Good. We've got two things that have worked so far - one of them by accident.
- So you're flying a configuration in which you regularly have the bridle in contact with the basetube and you have something on the basetube capable of cutting through the towline. Anybody see any potential problems with that?
By 2:23 I'm on the ground.
As you would've been eventually if everything had gone according to Plan A. So I guess we can log this one as a success and valuable addition to our huge track record.
If you look at the angle of the glider with the horizon at around 1:40 and compare that with the angle at 1:54 you can see that I'm headed nearly straight down.
Please relay my compliments to your winch operator.
On the ground thinking, "Hey, I'm down, alive, and I don't hurt. Amazing."
Cool! How much they charge you for the tow?
At the top of my flight I was dragging about a mile of towline behind me.
There's no weak link anywhere in that system.
- I don't see one.
- You don't mention one.
- If you had had one you'd have been told that it's purpose was to increase the safety of the towing operation by blowing before you could get into too much trouble and you'd have been expressing astonishment about the fact that it didn't work.
There was no reason for a weak link to have blown in the course of those events and it wouldn't necessarily have done you any good if you had snagged the towline on something - but it sure wouldn't have hurt anything at that point. (And it also might have blown in response to the parachute opening and simplified your situation a bit.)
Harold had released the power to both winch drums and watched the line scream off both drums at a rate he'd never seen or heard before.
I'll bet he was really surprised. Probably never really thought much about what would happen to a glider with a jammed release.
He was pretty much terrified.
Much too terrified to reach for the machete they always kept mounted on the winch for just such an occasion.
I'm really sorry Harold.
I wouldn't be all that fucking apologetic. NOBODY, especially a goddam brand new...
Linwood Lyons - Moraga, California - 93088 - H2 - 2013/06/05 - Patrick Denevan - FL ST 360 FSL
...Two, should be put up on a system that - in the absence of a low level lockout - has such a degree of nothingness in the way of checks, redundancies, and Plans Bs and Cs that a single locked up release puts him as close to getting killed as you were.
That, for the purpose of the exercise, WAS a KILL.
- And I notice that it was you - not Pat Denevan, Harold Johnson, or anyone else from Mission Soaring Center - who published anything in the way of an incident report.
- And it's a real safe bet that Mission's gonna continue operating WITH:
-- that idiot fucking autorelease / whipstall inducer
and WITHOUT:
-- launch assistants
-- launch dollies
-- hook-in checks
-- the best commercially available release for the job
-- an emergency release that allows the pilot to blow tow with both hands on the basetube
-- a weak link
-- a guillotine
Yeah, he may have been getting away for decades with the shoddy crap system he's been using but your getting killed a couple weeks ago just made all the cut corners not worth it.
And as far as I'm concerned the fuckup with the three-string was Mission's fault - not yours.
- You were equipped with a release that COULD be fucked up - and you're not the first person to fuck up a three string in that manner.
- You were inadequately trained to connect and preflight it.
- There wasn't so much as a radio check's worth of verification.
When Harold hit the gas it was on four very dangerous assumptions... that you:
- were hooked in
- had your leg loops
- had a release good to go
- wouldn't get into a low level lockout and need three hands to manage the situation well enough to survive
And the archives are littered with really ugly and fatal consequences of all of the above.
Okay, parachute did deploy and I've landed. Now what? Where am I?
Wing spar broke and ripped the fabric. I'm two roads over from where I started and not sure how I got this far off course. Parachute is out in the road, but still in good shape.
