Releases

[Tad Eareckson]

If you're still skimming there won't be - but no matter what you're doing you don't wanna be looking straight down at the pulley while the rope running through it is still connected to you.

[Steve Davy]

Thinking about a way to install your keel release without drilling the down tube.

Imagine a barrel with a pulley built into it with its axis vertical.

In other words, where you have installed a bolt though the barrel install a pulley.

Imagine a line exiting the top of the port down tube going around a pulley (same as vg) continuing on to the barrel pulley and attached to the starboard side of the keel opposite of the pulley.

Just brain storming a bit.

[Steve Davy]

So switch them to the Koch two stage.

- Your hand has to come off but it's the best of that breed - just a quick slap at your chest then back to regular business.

I have never seen a Koch two stage and don't have clue how the mechanism works. I am wondering how/if a mouth release could be incorporated into the design.

[Tad Eareckson]

Thinking about a way to install your keel release without drilling the down tube.

Why?

Imagine a barrel with a pulley built into it with its axis vertical.

That's a bit of a deal breaker. The factors which affect the efficiency of the mechanism, the load to actuation ratio...
- straight pin
- long pin
- minimal barrel inside diameter

You want the pin held as straight back as possible so the tension is trying to...

http://www.flickr.com/photos/aerotowrelease/8311348069/


http://www.flickr.com/photos/aerotowrelease/8312399698/

...compress the engagement area of the eye and you're minimizing the side loading of the pin.

The more you widen the barrel the more the:
- pin:
-- rotates towards the open position
-- is side loaded and subjected to distortion force
- tip of the pin presses into the side of the barrel

Imagine a line exiting the top of the port down tube going around a pulley (same as vg)

I just had to drill two holes in the keel to mount the cheek pulley.

...continuing on to the barrel pulley and attached to the starboard side of the keel opposite of the pulley.

I think I just had to drill another hole or tow in the keel.

I'm not entirely following this but bear in mind that...

When you're doing:
- VG you're shooting for a target inside the double surface and above the keel
- two point release you're shooting for a target below the keel and double surface

And you're better off with a release harnessed to the keel and free to rotate a little so that the load is nicely distributed and the mechanism remains directly opposed to the bridle tension at all times - versus hard mounting a Schweizer type release like they have on a Dragonfly.

Just brain storming a bit.

Great. The more the merrier, but...

- I hate drilling and surgery at least as much as the next guy.

- I'm massively anal and my release design evolved over a long time, is minimally invasive and EXTREMELY efficient, and it's gonna be pretty tough to improve on.

[Tad Eareckson]

I have never seen a Koch two stage and don't have clue how the mechanism works.

http://www.youtube.com/watch?v=mDStOEaOqHY


http://ozreport.com/toc.php?9.038&rss=1

For surface tow - other than platform - you wanna launch with the tension routed over and not interfering with the basetube. But as you climb and your tow angle increases the line over the basetube will start pulling down and back on the basetube and restricting your climb.

Solution...

- Put a Koch two stage on your chest.

- Use a split towline configuration to engage.

- The short top line is engaged by the first stage of the release mechanism which is actuated by a long lever.

- There's a longer bottom line which is routed under the basetube and is engaged by the second stage of the release mechanism which is actuated by a short lever.

- At launch the bottom line has sufficient slack to allow the bar to be stuffed and the glider to reach a high tow angle without interference.

- When you reach a high enough tow angle that the top line interferes with the basetube or soon will, you carefully hit the end of the long lever to trigger the first stage, dump the top line, and transfer tension to the bottom line.

- When you've maxed out your climb you swat with your hand more inboard to get both levers (the upper's no longer doing anything) and kiss the tow line by-by.

- In a low level emergency you swat inboard on both levers and dump both the tight upper line and slack lower one simultaneously.

I am wondering how/if a mouth release could be incorporated into the design.

It could but I'm not sure it's worth it.

Aerotow is where the danger is and, happily, because the tow angle is pretty much fixed and zero, where the fixes are easy.

On aero you're on a short, fixed length towline, you're flying fast 'cause the tug can't afford to slow down much - especially at the most dangerous phase of the tow (its beginning), there's a long skim before the two of you can climb out, and the guy supplying you tension is busy flying his own plane and having to watch you in a mirror when he can.

On a surface tow you can use a long towline, do a steep climb out, adjust the speed and/or tension to anything you want, and have a driver who can afford to keep a good eye on you all the time.

I don't think the incidents are there which indicate a problem particularly worthy of fixing. (But it would be nice to get the bulk down a bit without making it harder to blow.)

[Steve Davy]

Why?

Although I'm not very good at it, it's fun to think.

The attachment point of the release to the keel doesn't affect trim. The attachment point of the tensioner to the keel doesn't affect trim.
The position of the pin eye fore/aft sets the trim.
The ideal point from which to pull the barrel aft would be dead center of the pin of the D shackle link attached to the keel.

Are any of those correct?

[Tad Eareckson]

The attachment point of the release to the keel doesn't affect trim. The attachment point of the tensioner to the keel doesn't affect trim.
The position of the pin eye fore/aft sets the trim.

Mostly right. In fact much righter than I got it at the end of:

http://www.kitestrings.org/post1793.html#p1793

Need to fix that.

There's also an up/down thing going on.

- What tensioning to the nose does is move the release - and bridle end - up and forward.

- Both of those repositionings move the trim point fore of what it would be if the release weren't tensioned to the nose.

- The effective trim point on the keel is determined by extending the line defined by the upper bridle section - from the tow ring to the primary release - to its intersection with the keel.

The ideal point from which to pull the barrel aft would be dead center of the pin of the D shackle link attached to the keel.

Right. I need to route the lanyard tension through the pulley upon which the primary release is built. That introduces an offset (half the sheave diameter) which means I'm pulling the barrel a bit up as well as back and that introduces an inefficiency.

If I can extend the length of the mechanism, as I can when I'm mounting it on my shoulder:

http://www.flickr.com/photos/aerotowrelease/8312402264/


the offset angle and resultant inefficiency become negligible.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=4333
Gear Review - LMFP Tow Release

Bill Reynolds - 2007/11/12 20:36:33 UTC
Florida

Gear Review - LMFP Tow Release

Oh good. A Gear Review of a piece of shit that's been around for at least fifteen years and is so notoriously dangerous that not even Ridgely will sell it - although they have no problem whatsoever with people towing with it 'cause it's Industry Standard and not homemade.

Have you ever been on tow, and your glider banks one way and the tug goes the opposite way?

I dunno... Have you ever been on tow in thermal conditions?

You're already pretty high so you try to save it, shifting all your weigh to the high side. But the situation does not correct so you think...
RELEASE!

I was in this situation and here is how I reacted...

My tow release was the hand-brake type mounted on the down tube. To release, I'd have to let go of the control bar and hit the brake. Since I was using all my strength with both hands white knuckled on the base control bar to hold my body to the high side, my mind wouldn't let me release because if I did, I wouldn't be able to hold myself to the high side anymore, and I'd fall hard to the low side, possibly losing the control bar completely and swinging around wildly.

And this situation was never a consideration before you were in it? What total fucking assholes "trained" you, sold you this junk, and signed your ticket?

So what did I do? This all happened within a few seconds. I continued holding to the high side, the weak link broke...

The standard aerotow weak link?

...and I recovered pretty easily.

Yeah, the Ryan Voight instant hands free release comes through once again! And you didn't even hafta roll it harder and push out!

So how much altitude did you lose when you recovered pretty easily?

After that, I got more nervous about aerotowing than I already was.

Why? When you failed to maintain the correct tow position (centered, with the wheels of the tug on the horizon), the weak link broke before you got into too much trouble.

I immediately went up again, though, and had an uneventful tow. Later, I thought about what happened.

Ya know, dude... BEFORE I went up on my very first tow - 1980/11/14 - I was thinking a lot about what could happen.

What I most remembered was that even though I wanted to release, the thought of letting go of the control bar set alarms off in my head because I knew I would fall to the low side, which would probably break my grip on the control bar completely.

Do ya think? Again, what total fucking assholes "trained" you, sold you this junk, and signed your ticket?

After that day, I was on the internet and dicovered the Lookout Mountain Flight Park tow release.

You DISCOVERED it? In late 2007 you DISCOVERED it?

This tow release attaches to the control bar, and there's a loop, like a shoestring, that goes around your hand. When you want to release, you just jerk your hand about an inch and it releases.

Yeah.

http://vimeo.com/17472603

red
http://www.youtube.com/watch?v=pC1yrdDV4sI

27-41810
http://farm6.staticflickr.com/5579/14820212815_4a9087727f_o.png


http://farm6.staticflickr.com/5559/14633508440_7b54ea6235_o.png
30-41826

Sure it does.

You don't have to take your hand off the control bar!

Ralph Sickinger - 2000/08/26 22:18:20 UTC

Under sled conditions, I decided to borrow Brian Vant-Hull's glider instead of setting up my own, since we both fly the same type of glider. Brian's release is a different style, but I tested it twice during preflight to make sure I was familiar with it. After towing to altitude, Sunny waved me off; I pulled on the release (hard), but nothing happened! After the second failed attempt to release, I thought about releasing from the secondary, but before I could move my hand the tug stalled and started to fall; Sunny had no choice but to gun the engine in attempt to regain flying speed, but this resulted in a sudden and severe pull on the harness and glider; I was only able to pull on the release again, while simultaneously praying for the weak link to break. The release finally opened, and I was free of the tug.

Unless you hafta go to your Industry Standard...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3107
I have a tandem rating!!!

Lauren Tjaden - 2008/03/23 22:20:15 UTC

The barrel release wouldn't work because we had too much pressure on it.

...backup release.

Well, I ordered one and finally got to try it at the Florida Ridge recently.

Is that an answer to my questions about what total fucking assholes "trained" you, sold you this junk, and signed your ticket?

The first thing I noticed when I was on the cart getting ready to launch was that it wouldn't take much movement to inadvertantly release it.

I dunno...

Brian Vant-Hull - 2000/08/28 22:49:13 UTC

I purchased my release (the one Ralph used) at Lookout Mountain over a year ago, but never had any problems until the Ridgely Fly-In, where the same thing happened. I pulled three or four times on the release, then finally went to the secondary, by which time I was high above the tug and Sunny was frantically waving me off.

I've found it to fail this way once more since then, then on Ralph's flight, for about one time in ten.

You might might be in better shape on that score than you think.

So I got it looped around my hand and made sure I had my hand firmly gripped on the control bar where it needed to be, and made a mental note not to move it while under tow. I test released it a couple of times, and then I was off. It worked like a champ.

The United States Hang Gliding and Paragliding Association, Inc.
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
12. Hang Gliding Aerotow Ratings
-C. Aero Vehicle Requirements

05. 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.

Under what loading?

In summary, I highly recomment the LMFP tow release. I have a lot more peace of mind knowing that I can release a lot quicker and without letting go of the control bar if I get into any trouble on tow.

Oh. You buy one of these pieces of shit, slap it onto your glider, and get it to work twice on the ground under no load and once in the air with the glider straight and level at regularly scheduled wave-off at well under half the tension of your pathetic fucking loop of 130 pound Greenspot standard aerotow weak link and you highly recomment it?

And THIS is a GEAR REVIEW?

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=4333
Gear Review - LMFP Tow Release

xerxes - 2007/11/12 20:43:35 UTC
Atlanta

Yea, I'm pretty impressed with it too.

Me too. So far his experience indicates a one hundred percent reliability rate.

Similarly to the bike-handle release, don't forget to lock it, and test the full range of motion at the tow point because you don't want any tension on the release cable when going around turns etc.

You actually don't want much in the way of tension on the release itself either. Try to get off tow before the tension gets much over half a standard aerotow weak link.

-
H2 AT FL CL FSL
Mark IV

Socrates Zayas - 2007/11/12 21:00:20 UTC
Miami Beach

I use both types...

Brake in Florida and Loop in LMFP: Reasons? Because the situations that one feels during tows are different at both places...

Huh? Can you expand on that a little? This may possibly rank amongst the top five most moronic things I've ever heard anyone say in the course of my entire experience with hang gliding.

Fact is that the situation you explain only occurs when you take your eyes off the tug for a thousand of a second. Ok fess up the real story we all fly here and we all have had a lock out at some point in our beginning phase.

Yeah.

Bill Bryden - 2000/02

Dennis Pagen informed me several years ago about an aerotow lockout that he experienced. One moment he was correcting a bit of alignment with the tug and the next moment he was nearly upside down. He was stunned at the rapidity. I have heard similar stories from two other aerotow pilots.

1. The laws of physics dictate that lockouts are ONLY possible if you take your eyes off the tug. There's no possible way you can get kicked out of line by a thermal.

2. And, of course, lockouts are only issues for beginners. Once you've got a dozen or so tows under you're belt you'll have mastered this towing thing and can go up on any piece of shit the flight park has in the display counter.

Mine was an experience the tug and air was so rough the vario pushed into me and I looked to the side for an instant and there she was! The Tug went Right, I kept left and locked out!

Right. 'Cause that's how you locked out once no other explanations are even worth looking at.

What are these orange growers spraying on their orchards that's making its way into the drinking water down there?

Fortunately I had just been tested with Lockouts by both Rex and Dan and knew it was about to happen and released.

1. So this was a Florida lockout and thus there was no advantage to being able to release with both hands on the basetube.

2. And you're fuckin' stupid enough to "think" that because Rex and Dan put you through a couple of bogus simulations of a lockout at two grand in smooth evening air you're gonna be just fine when the real deal hits the fan at seventy-five feet.

Fact is every lockout story I have heard to date fell in the "I looked away for a second" and was: fill in the blank (to low, high, right, left...) and locked out.

How bad does it hurt your neck when you stick your head that far up your ass?

It is the most dangerous part of our sport, towing that is...

It probably comes in well behind the hang check and standup landing.

...and to not divert 100% of your attention for 5-8 minutes is just irresponsible.

Fuck you, buddy.

- Yeah. Sometimes people DO get out of position 'cause they get distracted by something. That was probably one of two factors - the other being this piece of shit from Lookout that all you assholes are drooling over - that's gonna get Roy Messing killed less than twenty-two months from now. But he was still a flight or two away from scoring a Two, that was his NINTH aerotow, and he didn't look away 'cause he was just irresponsible. He looked away 'cause he thought he saw something wrong and he's human.

- And if the fuckin' useless tug driver hadn't put him up on fuckin' useless shit equipment it's very unlikely that getting distracted for a couple of seconds would've been a deal breaker.

It could cause injury to you...

Yeah, it COULD. But that's the only case I know about in which it was very probably a contributing factor. 'Cause in the other 99.9999 percent of the launches people are GLUED onto the tug until they get well clear of the kill zone. And after they've gotten up a couple of hundred feet it doesn't matter much if they start doping off a little.

What actually DOES cause injury to you is the piece of shit Industry Standard:
- a) two point release;
- b) one point release;
- c) 130 pound Greenspot weak link;
- d) tug driver always ready to make a good decision in the interest of your safety.

Speaking of "c"...

Socrates Zayas - 2008/05/21 23:53:23 UTC

The cycle was nice, nothing out of the ordinary, but just as the tug flew over the fence line of the orchard the weak link broke. It was as if it didn't even break - Eric and I both thought it was a release malfunction.

Axel Banchero - 2008/05/22 04:19:39 UTC

Doc's body wasn't moving and we were shitting our pants until he started talking confused. The first thing I saw was his eye bleeding and swollen the size of an 8 ball. There was sand and dirt inside. Looked like he lost it at first until he could open it a little bit.

You're a bit over six months away from a demonstration of just how much a standard aerotow weak link can improve the safety of safety of a towing operation.

But, hey... You're gonna keep the tug nice and safe and that's the really important thing.

...and worse to the tug and pilot.

FUCK the tug.

- You name me ONE tug who's been scratched because of the irresponsible actions of glider.

- I can name you a shitload of gliders who've been crashed, hurt, or killed because of the front end assholes forcing them up on shit equipment, outclimbing them, and dumping them.

Not getting on you but would like to know why you missed the tug going right???

Who the fuck cares?

- Are you suffering from the delusion that you can't have the glider going one way while the tug's going the other unless someone's done something irresponsible, negligent, or stupid?

- Is it OK to fly with shit equipment that'll send your probability of survival to hell WHEN the glider's going one way while the tug's going the other because someone's done something irresponsible, negligent, or stupid?

- So why aren't you getting on the tug for missing - or not giving a rat's ass about - the glider locking out to the left and turning right? Who's supposed to be serving whom in this arrangement? Who's paying for the goddam gas and driver?

P.S. I'm afraid I missed the part about why a brake lever actuator works better for Florida air and a loop actuator works better for the Georgia stuff.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=4333
Gear Review - LMFP Tow Release

Bill Reynolds - 2007/11/12 21:08:41 UTC

Hey Doc,

What happened was my right wing got lifted, so I was already trying to correct when about the same moment the tug suddenly turned right, making the situation worse.

In other words... You were doing everything right, everything possible to stay lined up, and the tug really didn't give much of a rat's ass about the safety of the tow and the guy who's paying him for the ride.

I think I was paying attention ok...

No way dude. You were being irresponsible and endangering the tug and it's pilot.

...just had events working against me.

Yeah. Just had EVENTS working against you.

With the new tow release, though, I won't hesitate to release If this happens again.

And you've tested it to make sure it'll function while you're not hesitating while you're going one way and the tug's going the other, right?