Releases

General discussion about the sport of hang gliding
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Tad Eareckson
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Re: Releases

Post by Tad Eareckson »

This is an issue with all spinnaker releases, correct?
Yeah.
I thought this was only a risk when they're used in a one-point configuration.
I don't buy that there was enough twist in the towline to precipitate Robin's lock. I think that if he'd been using a conventional two point Wallaby arrangement and botched putting the weak link on the bridle end the same way he botched putting it on the towline end - whatever that was - he'd have wound up just as dead.

Note that there was no photo of the critical malfunction released. The whole followup of the fatality was an exercise in ass covering to take as much heat as possible off the meet organizers and the Wallaby / Moyes release and dump as much as possible on the dead competitor and his nonstandard aerotow weak link.

That being said...

The risk of a snag is very low and manageable.

But why risk and manage it when you can spend fifty bucks (?) on Joe's release and totally eliminate it with a mechanism and assembly designed to do the job?
No, I haven't, and don't really understand what there is to adjust.
I was referring to the adjustment on the bicycle - just to be clear.

- You have to use pliers to hold tension on the brake cable while you use a wrench to start clamping down on the adjustment. A wee bit too long and your lever bottoms out on the handlebars before you get safe stopping power. A wee bit too short and your brake pads drag on the rim.

- And if your wheel isn't well trued - if there's a bit of wobble on the rim - you got problems.

- Same deal on the Wallaby release. Too long and you have to go to your "backup release". Too short and you're holding the latch partially open and subjecting yourself to a good possibility of a premature release - which, if you use a standard aerotow weak link, you may not even notice. (Some of the Wallaby releases have throttle cable adjusters which help to tweak things.)
So do these releases fail after working initially because this adjustment changes?
It's mostly a matter of the bends. It's a bad idea to put one of these levers on the basetube 'cause of the extra bend (which is why most people DON'T put them on the basetube). And lotsa people anchor to the carabiner and that bend changes with control input.
Could it be prevented from changing (perhaps through better manufacturing)?
You're talking about manufacturing a better piece of shit instead of doing the job right and building it into the glider which is twenty times easier and cheaper. And we've got Joe's release which isn't perfect and has a couple of small issues but if you adjust the bottom end properly and preflight it it's perfectly SAFE.
Can the adjustment problem always be detected on the ground, or can it happen post-launch?
Lose it. Joe's release makes all other cable based releases obsolete. There's zero excuse for putting ANY of them in the air EVER again.
Do brakes on bikes ever have to be readjusted for the same reason?
No. They're built in and well engineered, there's no variation in the bend on the front brake cable and precious little movement with respect to the rear, and as long as the rims stay true you're good to go - or stop.
...(though I have no idea what it's L/A is).
I got a load to actuation ratio average of 16.14 on the spinnaker shackle and the brake lever assembly gives about a four to one mechanical advantage boost.
Instead, if I'm following you, it can enter a state where NO force will actuate it.
Yeah.

http://www.hanggliding.org/viewtopic.php?t=11497
Aerotow release options?
Axel Banchero - 2009/06/20 04:57:01 UTC

I just kept hitting the brake lever for a few seconds in WTF mode, and the instructor used the barrel release.
If it's out of adjustment the lever will bottom out before anything happens.
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Tad Eareckson
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Re: Releases

Post by Tad Eareckson »

Hey Zack,

Next time you land that tail dragger of Gregg's...

http://vimeo.com/37468810

red

...do me favor and stow the bridle first. That was really painful to watch.

If your don't have time to stow it just yank the bridle up and bite the midpoint. Or use a barrel release and dump it low on final.
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Re: Releases

Post by Zack C »

Yeah, after I posted the video here I watched it and thought, 'Tad's not going to like that...' Sorry about that. I actually did stow the bridle but it apparently fell out of wherever I stuffed it...I had no idea it was dangling behind me until after I landed.

Zack
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Tad Eareckson
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Re: Releases

Post by Tad Eareckson »

I actually did stow the bridle but it apparently fell out of wherever I stuffed it...
Oh yeah - I see upon review.

What I'd do...

- Ten inch length of eighth inch bungee.

- Fold it in half and tie the ends together using a Thumb Knot (an Overhand Knot with the two strands).

- Slide a cord lock (like on a stuff bag drawstring) on the resulting loop.

- Put the loop over your left thumb down to its base and set the cord lock to make it snug enough to hold it it place. You can see a little bit of what I'm talking about at:


Image

- Whenever you get a spare moment after release sloppily Figure 8 coil the bridle over your left thumb.

- Loosen the cord lock, pull the bungee loop over the coiled bridle, and tighten the cord lock snug.

- Rock up to take the pressure off the front of your harness and stuff the bundle inside.

- If you drop it you don't have ten feet of bridle to coil up again.
...I had no idea it was dangling behind me until after I landed.
How did it fare? (If it got chewed up lie and tell me it's fine.)
Zack C
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Re: Releases

Post by Zack C »

Tad Eareckson wrote:How did it fare? (If it got chewed up lie and tell me it's fine.)
No need to lie...it's fine...no noticeable damage.

Zack
Steve Davy
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Re: Releases

Post by Steve Davy »

Tad,

What release system would you recommend for scooter towing students up to one or two hundred feet?
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Re: Releases

Post by Steve Davy »

Don't worry. No fuckin' way I'm getting anywhere NEAR that cone while I'm still connected to the towline with an aerotow type V-bridle and release system which works well for scooter towing. I'm probably gonna try to sneak it back a few yards when nobody's looking.
I'm not sure what you mean by this.
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Tad Eareckson
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Re: Releases

Post by Tad Eareckson »

1. Dolly launch them - or, better yet, use Gregg's tail dragger trainer. A huge percentage of your potential problems disappear when you do that.

2. Use my built in aerotow release system for the ground skim stuff. If Wills Wing can build the fuckin' Condor for training they won't have any problem whatsoever building in a release system to go with it for an extra hundred bucks.

3. Failing that use Joe Street's release.

4. When they start towing higher they're gonna start having basetube interference issues with the aerotow bridle.

5. 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.

- You lose the speed assist of having a keel attachment but - big fuckin' deal...

- - - The student has developed some developed some proficiency at this point and can suffer holding a little bar pressure for five or ten seconds.

- - - People in Europe do this as a matter of routine.

- - - The higher the tow angle the more irrelevant the keel attachment becomes.
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Tad Eareckson
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Re: Releases

Post by Tad Eareckson »

I'm not sure what you mean by this.
The bridle's over the basetube. Shortly before you reach the pulley it'll start pulling back on the basetube. After you pass the pulley it's gonna stuff the bar and dive you in. That's a really good and proven method of getting you killed fast.

And the releases Steve's using suck - and he knows it.
Steve Davy
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Re: Releases

Post by Steve Davy »

Shortly before you reach the pulley it'll start pulling back on the basetube.
I had not considered there could be any problems BEFORE reaching the pulley. Duh.
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