http://www.hanggliding.org/viewtopic.php?t=11519
Aerotowing methods
Bill Reynolds - 2009/04/13 22:03:57 UTC
I have to tow in a head up position so my barrel releases don't rub on the base tube and accidently release. It feels squirrely like this and seems to add bar pressure.
Ryan Voight - 2009/04/13 22:22:13 UTC
Point of the Mountain
Aerotowing methods
"Pro-Tow" pros:
Yeah, definitely put that one in quotation marks.
-Simplicity. One (short) bridle attached to shoulders.
But always make it long enough to wrap at the tow ring - 'cause that's the way we've always done it. And, for good measure, make it thin too.
-Release located right in front of your face, easy to see and find (if you have a barrel on each side, the same is true for the backup release).
Right. 'Cause when the shit hits the fan you're always gonna have the time to see and find something.
-If you have a barrel on each side, it doesn't matter which hand you reach with, and you don't have to decide which hand you'll use when attaching the release (which you do have to do with the break-handle releases).
1. And, of course, no matter what hand you REACH WITH the glider will be fine 'cause you've got it set on autopilot to continue holding speed and fighting the turn.
2. BRAKE.
3. A motorcyclist has a "brake-handle" on his control bar. But a motorcycle isn't designed by idiots, the lever is at his right hand so he doesn't have/get to "decide" which, you never hear about motorcycle wrecks which occur 'cause someone couldn't reach the lever, and there are no analogous idiot discussions on motorcycle forums.
"Pro-Tow" cons:
-No help with pitch pressure. It's fine on a U2, especially at 1/2-3/4 VG, but I wouldn't want to "pro-tow" a Falcon for too long.
-If you get off to the side of the tug, the pro-tow pulls your shoulders over... I've seen a lot of people cross-control rather than get their legs over behind their shoulders.
Yep, some folk have absolutely no feel whatsoever for flying hang gliders and probably shouldn't be flying them.
V-Bridle pros:
-Helps with pitch pressures
-If you get off to the side of the tug, the v-bridle dampens how far over your shoulders get pulled (see above), but also pulls over on the glider, so you only have to do half as much correction, the other half is done for you.
-Break handle is easy to slap in an emergency, rather than locating, grabbing, and pulling a barrel release.
I tried to release but my body was off centered and could not reach the release.
Right. Never a problem slapping a BREAK handle. And it's not like you ever hafta locate it. I mean, it's right there on the downtube in the same place you put it when you were in the setup area.
V-Bridle cons:
-More bridle hanging after you release.
-More to set up before hand.
-Insignificantly more drag than "pro-tow"
Right. Insignificant. Just a glide point or so. I don't even know why they bother installing the VG actuation stuff INSIDE the downtube when they could just velcro some cable to the outside.
-Spinnaker upper release can LOOK closed, when it's not
BFD. I only know of one death catalyzed by that little shortcoming. And the passenger got off with just a concussion.
-Speed limit, tow pilots must not go to fast!*
* I was once towing behind Rhett (using a V-Bridle) and instead of waving me off at the end of the tow, he decided to play 'chase the ace' and see if I could follow. When he couldn't shake me, he began accelerating. As he sped up I pulled in more and more. As I got towards full-bar-stuff, I watched the tow line start to slide up the V-Bridle (since my AofA was now significantly lower than normal). As I pulled in more, and the line slid up the bridle farther and farther, the glider began entering violent oscillations. I slammed the release and climbed out to burn off the speed.
One time I saw someone that was used to truck towing attach his V-bridle to the nose, rather than the biner. Somehow no one noticed, and he launched. As he released from the cart his glider went into very similar oscillations, until it flipped upside down and impacted the ground.
Funny we never managed to hear about that one from the USHGA "accident" reports. Mind sharing the date and tow operation?
After my experience behind Rhett, I thought about that accident I had seen. It seems towing a glider from the nose causes it to oscillate and flip upside. I believe that, as the tow line slid up my v-bridle, it simulated the towing from the nose situation I have witnessed before.
It's only an issue if you're playing games, aerotowing at full-bar-stuff speeds... but worth mentioning...
We've got enough death and destruction going on with aerotow - mostly as a consequence of shitrigged equipment and shitheaded operators - without needing to play games, thank you very much.
Adi Branch - 2009/04/14 13:20:10 UTC
I have to ask this, in the US why is it that you still seem to be using methods such as barrel releases as the main release mech?
Because that's what the Flight Park Mafia sells. You got a problem with that?
Ryan Voight - 2009/04/13 22:25:27 UTC
I have to tow in a head up position...
Sounds like your pro-tow bridle is too short... a longer one would locate the barrel in front of the base tube.
A longer bridle will do absolutely NOTHING to relocate the release and a lot to increase the wrap potential. He needs to extend the releases and shorten the bridle.
Ryan Voight - 2009/04/13 23:27:29 UTC
But don't forget the weaklinks- one on each side!!!
Dallas Willis - 2009/04/14 00:08:15 UTC
Ryan are you serious?!?!
One weaklink on the side you don't normally release from is all you need (less wear and tear on the weaklink). 2 weaklinks = 2 chances for a weaklink to inadvertently break which is bad.
How very odd. I've never heard that weak link failure could be anything but a blessing.
If you release one side and it hangs up, the solution is to ditch the other side not rely on another weak link which is only there to prevent the glider from blowing up.
1. The only way it can hang up is if the bridle's too long - but nobody's ever gonna listen to me on that one so let's go to...
2. So the weak link is only there to prevent the glider from blowing up. So now you're locking out and there's no longer a weak link on that side so now - obviously - it's no longer important to keep the glider from blowing up. Or overloading the release.
3. Are you gonna say anything about the dual bent bin releases?
4. If the weak link is only there to prevent the glider from blowing up do you think you can use something heavier than a loop of 130 pound Greenspot that'll still blow well before the glider does? Think about this one carefully Dallas - you're a goddam aerobatics pilot ferchrisake.
Rick, most folks flying a U2 will go with just a pro-tow system. However if you don't plan on towing all that much *and* given your concerns from your other post about not wanting to take your hands off the control bar, then I'd certainly advise you to go with the "lookout" style...
And don't even consider any of the many one point options for putting an actuator in your teeth.
...2 or 3 point (depending on your definition of "point")...
Let's stop allowing individual definitions on this. Pilot only - one point. Pilot and glider - two point.
...and attach it to your carabiner. Just make sure your carabiner gate faces toward the back of your glider.
Yeah, huge danger of blowing your carabiner apart from the inside. No danger whatsoever of your locking mechanism ripping your parachute bridle to shreds.
Also you're around some great pilots in the Denver area, Jim Yockum, Joe Nance and JT will take good care of you. Trust them.
Trust NO ONE - especially great pilots.
Bill Reynolds - 2009/04/14 13:49:06 UTC
Adi, you must be asking about the black thread, which is the weak link. I have it on the left barrel. I use the right barrel to release, but can release the left if necessary. The weak link is strong enough to handle normal tow pressure but is supposed to break in a lock-out or other over-pressure, thereby letting me off the tow line without me releasing.
Yes. Tow PRESSURE.
Yes. A weak link is SUPPOSED to break in a lockout. And if you don't like all the videos and fatality reports in which they don't - hell - just ignore them.
Yes. Lockouts are always over-PRESSURE events.
Craig Hassan - 2009/04/14 14:02:26 UTC
Ohio
I don't see much of a benifit with these over the brake release. Still have to let go, maybe less failure of the components, but do the brake releases fail often? That is if you hit the lever and actuate it as opposed to knocking it off to the side.
Yeah Craig, never worry about a LITTLE failure of the components or the lever occasionally migrating to the side when you try to hit it. Chances are that when there's a fatality it'll happen to someone else.
Marco Weber (selbaer) - 2009/04/14 14:08:26 UTC
Tampa
All I have done so far is aerotowing. No winch, scooter, platform or truck, boat towing so far and the barrel looks just fine to me in its simplicity. It's pretty idiot proof.
But I've had it once where the pin had bent inside the barrel from excessive tow force. My weaklink was still intact. The tug pilot's weaklink broke so I had the rope. I had to use two hands to get the pin out of the barrel.
It's NOT idiot proof - quite the contrary 'cause only idiots use them. But don't worry - the important thing is that it LOOKS just fine to you in its (and your) simplicity.
Craig Hassan - 2009/04/14 15:10:21 UTC
The only part of my get up I change between scooter and areotow is the weak link.
Why? Does your glider break at different stresses on scooter and areo?
I use the same 2 barrel set up I always use. Keeping things familiar is more comforting to me!
Yeah, I really hope you keep things familiar so you'll always be comfortable and complacent.
It is just a barrel on each shoulder and 4' or 5' so bridal.
Yeah, keep that BRIDAL nice and long. People who spell it that way always do.
I use a weak link on the left hand side, since I release the right side 99.9% of the time.
I can hit the release without looking almost always on the first try. (Almost is not 100% and the time I really need to hit it I'll probably miss!)
That's GREAT!
Just practice with your left hand one out of a thousand tows 'cause it's almost always OK to sacrifice the control afforded by your right in any emergency situation.
And if you can almost always get it on the first stab in normal situations you should be JUST FINE when the shit hits the fan.
I also still have to let go of the base bar to activate it.
I can't really see that being a problem.
On guy took a bit of string and attached it to the rear of his barrel and holds it in his hand. All it takes is a flick of the wrist. Still has to remove his hand from the bar, but it is a much quicker release than reaching out to the barrel! ( and the pin doesn't get a chance to snap back on your thumb! OUCH! )
And don't even consider putting the other end of the string in your teeth. We do want to keep things sporting.
Here is a picture of the scooter set up (not me). I guess I was wrong I also change the length of the barrel strap. We usually scooter from a dolly with the line under the control bar, and need the extra length to keep the barrel from hitting the bar and releasing.
And of course now there's NO WAY those barrels can come into contact with the basetube. So now it's OK to keep the bent pins, short fat barrel, and flared tubing ends.
Ryan Voight - 2009/04/15 00:03:47 UTC
I have to ask this...
Why not? Simple, light weight, and foolproof. It's either closed or it's not. You give it a tug and it releases (every time).
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.
The barrel release wouldn't work because we had too much pressure on it.
But I've had it once where the pin had bent inside the barrel from excessive tow force.
Yeah, why not? It's simple, light weight, and foolproof. It's either closed - when you miss it, you're locking out and can't get to it, it has a little tension on it, or the pin has folded in half - or open - when it slides across the basetube when you're trying to pull your nose back down.
The basebar hit the ground first, nose wires failed from the impact, and at the same time she was hitting face first.
And you give it a tug and it releases (every time (almost)).
Rick Maddy - 2009/04/15 01:54:33 UTC
Denver
As for releases (based on the other thread) I will have barrel releases on both shoulders and I will most likely use the Lookout cable release. This way I can have my primary release in my hand, on the basetube. But instead of putting my hand in the loop I will most likely put a big knot on the end or some sort of disc - maybe 3/4" in diameter (or whatever size will be appropriate). Then I can just hold the knot/disc between two fingers. This will allow me to pull the release with a small movement of my hand but my hand won't be stuck in a loop.
Kinda like that, Rick?
Adi Branch - 2009/04/15 09:12:19 UTC
I'm still a newbie really, I don't know a lot of things, but it does strike me that requirement or standards in the US seem to be different...
The US has no standards, Adi - just a bunch of shitheads doing whatever the hell they feel like and telling other people what they can and can't do.
Dawson - 2009/04/15 11:56:18 UTC
Lake Macquarie
Is that the kind of weaklink (Tost) in the Koch release? How does it work? Where is it?
Adi Branch - 2009/04/15 14:07:49 UTC
No, it's attached between the tow rope and V bridle...
They're very similar to this exploded view one, taken from a sailplane site... the actual weak link is the bottom two bits, the rest is just housing.
Pros and cons of both types I guess. The more experienced of you may spot flaws with using these? I dunno...
The pros of the Tost weak links is they're made and tested to specific ratings and tolerances so you can use them for specific gliders and know what you have.
The pros of the 130 pound Greenspot is that its strength is whatever anyone says it is so you can use it on any one or two point bridle to put any solo glider at one G.
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