Video of surface tow, foot launching with Hewett bridle

General discussion about the sport of hang gliding
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llwest@comcast.net
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Joined: 2011/01/26 14:30:47 UTC

Video of surface tow, foot launching with Hewett bridle

Post by llwest@comcast.net »

http://www.youtube.com/watch?v=SGPZkrf94D4


I towed him once solo and once with his student tandem. It was worrisome to me, but his father (a master rated pilot and advanced instructor) walked us all through it and who am I to argue with a master/advanced instructor?
Watch and critique please.
You can see the terrain isn't very forgiving and the road had 1.5' foot berms on both sides so a cart would have been scary too, but at this point, I'm just picking how scared I wanna be driving up hangies. I feel much better about baggies, but would like to get my hangie chops up to snuff too.

We had a good 15mph headwind on the surface and a smooth 25 aloft with a nasty shear layer he had to pass through (I saw it on the tension gauge in the truck), so the consequences of a break were less than they would be no wind and we wouldn't have even attempted it in a no wind, but......a low level lockout was more likely with high launch winds.
He was on a 300 pound weaklink with the Center of Mass bridle (that I'm still trying to wrap my mind around as I remember Peter B. really explaining it to me about 5 years ago and convincing me it was "safer" than platform launch, but now I can't really remember the speech he gave me. I just pretty much was convinced and then never revisited his logic. I've only been towed myself with the CM bridle 10 times, but I'm going to try just a two-point (keel to towline attachment to waist) on a good day when everything feels right to see what the difference is. I'm looking at other options for doing a platform launch trailer and getting a winch and trailer set up for just hangies, but again, without more interest, it's hard to get the money and without the setup, it's hard to get the interest. Until then, we have to share this rig and do the best we can.
So....help me not maim or kill under the constraints I have now.
Thanks guys.

There it is.
Give me your thoughts.
llwest@comcast.net
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Re: Video of surface tow, foot launching with Hewett bridle

Post by llwest@comcast.net »

Oh, and he used a 2 loop, string release at the towline connection point and we had an 8m sutton flow form kite on the end of the line to keep the line off the dirt during rewind.
MikeLake
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Re: Video of surface tow, foot launching with Hewett bridle

Post by MikeLake »

As a comparison

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


Flappy string V kludge.
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Tad Eareckson
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Re: Video of surface tow, foot launching with Hewett bridle

Post by Tad Eareckson »

It was worrisome to me, but his father (a master rated pilot and advanced instructor) walked us all through it and who am I to argue with a master/advanced instructor?
I ended my flying career with 140 points over the 1450 I needed for a Five and a lot of maxed out categories but still twenty-six and a half hours shy of the airtime. I was certified as a Basic Instructor a couple of times. There's no difference between a Basic who's worked giving rides at Kitty Hawk for a week or so and an Advanced 'cept for the rating you have at the time you get it.

These credentials are virtually MEANINGLESS. There are zillions of total assholes who have them. Don't let yourself be impressed or intimidated by them. Neither of them requires anything in the way of brains or skill.

He's using a Skyting Bridle. Therefore he doesn't know what he's doing.
Watch and critique please.
- Have them clean the Vaseline off the lens first next time.

- It the early stage of the tow he's got two thirds of the tension routed under and in firm contact with his basetube.

- He's making substantial corrections and sliding the bridle from side to side on the basetube.

- That lateral movement is stopping JUST SHORT of the foam grips on the basetube.

- If he's ever in a situation in which he needs to go a LITTLE BIT farther than he is under these relatively ideal conditions the glider may not do what he wants and expects it to do.

- If a lockout resulted from this interference it would not be an unprecedented problem.

- The Germans knew what they were doing when they came out with the Koch two stage over a quarter century ago.

- Mike knew what he was doing well before that when he used a spreader bar to keep the bridle off the basetube.

- Two seconds elapse between the time his hand moves off the basetube and the towline goes bye-bye. Two seconds can be a VERY LONG TIME under less pleasant circumstances when one is holding a lot of bar pressure. One second can be a VERY LONG TIME under less pleasant circumstances when one is holding a lot of bar pressure.

- After the towline goes bye-bye he's still got fifteen yards of flappy string V kludge wrapped all over the control bar.

- There does not appear to be a tether on his hook knife.

- Nevertheless, it is of a lovely colour. Neon lime green would you say, Mike? I have an orange one.
...I'm just picking how scared I wanna be driving up hangies.
You shouldn't need to be too scared towing rated pilots. Legally, USHGA has always made real sure that the standards for procedures and equipment are shit or nonexistent so you're off the hook. Morally...

Make sure there's gas in the truck and the tires are good for at least another ten or twenty miles.

Mirror, tension gauge, pressure control, dump lever. Airspeed indicator might be fun.

The winch should be in good shape and I hope there's a levelwind.

The line should be properly wound and good for at least maybe eight hundred pounds - better a thousand.

The weak link should be one and a half to two times the maximum allowable flying weight of the glider. It should NEVER break. I'd use Tost.

The pilot's release must be able to handle two Gs. Go with Koch two stages.

Wheels. Wheels that will actually roll on the actual surface.

Streamers at launch and ahead here and there for 75 yards.

Screw the observer.

Somebody standing by the glider with a radio would be very nice.

Don't move the truck unless the pilot has demonstrated that he's hooked in within the previous five seconds.

Your job is to provide and adjust tension as he launches and climbs.

His job is to fly the glider and get off tow if he can't.

If he locks out and dies that's his problem - just like it would be if you launched a qualified Two off a mountain and he flew over the back and into a rotor. You can only do so much to save people from themselves.

I like the headwind.
...so the consequences of a break were less than they would be no wind...
Don't have breaks. You can't predict what will or won't happen after a break based on what the wind is or isn't doing. There are all kinds of mixed menus available for killing people towing - or suddenly not towing.
He was on a 300 pound weaklink...
Make it five.
...with the Center of Mass bridle (that I'm still trying to wrap my mind around...
THERE IS NO SUCH THING AS A CENTER OF MASS BRIDLE. It's an optical illusion like the "floating crossbar" of thirty years ago. Like a backup loop it doesn't do anything besides putting extra dangerous crap in the air and making stupid people feel better. Anybody who speaks of one - from Donnell to Peter to Dennis - doesn't know what he's talking about and doesn't understand the physics of a towed glider or a flown kite.
...as I remember Peter B. really explaining it to me about 5 years ago...
PETER B. IS A DANGEROUS IDIOT. Peter B. was a dangerous idiot five years ago, he's a dangerous idiot now, he will still be a dangerous idiot five years from now.
...and convincing me it was "safer" than platform launch...
There is NOTHING safer than a platform launch. And that's coming from a major aerotow freak. Read the fatality reports and see where we've been having - and not having - our problems over the past 25 years.
...but now I can't really remember the speech he gave me.
It would've been based upon Donnell's sacred Skyting Criteria which a sharp fifteen-year-old science student could blow apart in an hour or two if he gave them much thought.
I just pretty much was convinced and then never revisited his logic.
He's never had any - or common sense for that matter. All he's got is faith.
I've only been towed myself with the CM bridle 10 times, but I'm going to try just a two-point (keel to towline attachment to waist) on a good day when everything feels right to see what the difference is.
You don't need to. I can tell you right now.

They're both two point bridles and the attachment points either are or can be the same. Let's say they're the same and put one on your harness at your hips and another on a release on the keel a foot in front of the hang point.

Let's call your hook-in weight a hefty 250 pounds.

Let's make the 2:1 bridle one and a half times the length of the 1:1 bridle so the silhouettes when they're loaded up are identical. (With me?) And we'll call the apex angle(s) - at the tow ring - 60 degrees.

Let's pull 200 pounds tension with the truck and freeze the glider after it's off but the towline is still horizontal (so you're still in aerotow mode at this point).

With the 1:1 the ring on your harness and the release on your keel are equally loaded. It the bridle were infinitely long both points would be feeling half the tension - 100 pounds apiece. But since it ain't we gotta do a little trig and up those loads fifteen percent so those attachment points are both being stressed to 115 pounds.

The 2:1 bridle is a pulley system. Actually, so is the 1:1 bridle. In a pulley system the load is proportional to the number of strands. So the 1:1 bridle is delivering 230 pounds evenly / proportionally divided between two strands and the 2:1 is splitting it between three. So 230/3 equals (call it) 77 pounds. The release (keel) is getting one strand so it's getting 77 and you're getting two so you're getting 154.

Since the keel (glider) is (hopefully) always pitched up above horizontal and the upper attachment point is fore of the hang point, some component of the tow tension going there will (help) pull the nose down / trim the glider faster. The more pitched up the glider and/or the steeper the tow angle the more pronounced this effect will be.

You REALLY don't want all of the tow tension going to this point and you REALLY don't hafta try it in the air (like Jim - Prahl did) to predict what will happen - even if you are completely unaware of the numerous real life unplanned demonstrations.

Ignoring the trim effect, the glider doesn't give a rat's ass about what's going on with all the crap below it. All it knows is it's got something pulling straight down on it at 250 pounds and straight ahead on it at 200 pounds. (It doesn't care about things are being stressed in the course of routing the tow tension. It all comes back to the keel and you start out with 200 you deliver 200.)

You yourself really don't give a rat's ass about the trig either - just the forward vector you're feeling which is 100 pounds for the 1:1 and 133 for the 2:1.

So with the 2:1 bridle you're using a bunch of Rube Goldberg crap to reroute a few pounds of tension through you before it gets to the keel instead of routing them directly to the keel. Big Fucking Deal. It doesn't do anything either useful or that you're gonna notice - or if you do you can move the release on the keel an inch or two one way or the other to tweak the trim.

And Mike's using a Koch two stage clipped to his chest and he's got all 200 routed through him and even he's not gonna notice any really significant towing idiosyncrasies between the configurations.

And we're not using 200 anyway so the differences are gonna be even more insignificant.

And as the glider climbs / tow angle increases there's less and less justification for a two point bridle of any flavor and more and more reason for doing what the rest of the world does for surface towing and going one point.

If none of that makes any sense then just put a blindfold on and take one flight on a Hewett and another on a Koch and see if you could tell which was which.
...and he used a 2 loop, string release at the towline connection point...
Sounds anemic.
As a comparison...
Note that this guy isn't locking out and dying or having his chest crushed, releases in half the time, and doesn't have fifteen yards of flappy string V kludge wrapped all over everything immediately after release and for a long time thereafter.
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Tad Eareckson
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Re: Video of surface tow, foot launching with Hewett bridle

Post by Tad Eareckson »

It was worrisome to me, but his father (a master rated pilot and advanced instructor)...
Bill Cummings?
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Tad Eareckson
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Re: Video of surface tow, foot launching with Hewett bridle

Post by Tad Eareckson »

Well, Larry, until you drop by again I'm gonna assume that it was indeed Bill. I was trying to figure out what Hang Five sorta person would be hanging around Albuquerque setting up a son with a tangle of flappy string V kludge for a foot launch tow. As far as I know most of the more severe cases of Hewett poisoning are confined to geography under control of the Midwest Towmaster and his goon squad. But in New Mexico...

So let's have a little fun while we're waiting for the next fatal lockout...

http://groups.yahoo.com/group/hhpa/message/9355
Weaklinks, a different opinion.
Bill Cummings - 2010/02/03 16:24

For now I'll leave Aero Towing out of the weaklink conversation.

Besides having a weaklink to protect the glider from breaking it will also stop a glider from climbing into a nose high stall if it breaks at high speed under a lot of tension. (That was two things so far.)

A third thing I use a weaklink for is a back up for a release failure.

Many a time in the winter when snow machine towing we would run into frozen release problems with many different types of releases. Slush on the frozen lake would freeze at altitude. There have been more capture failures than freezing.

Rather than let go of the control bar to cut the Skyting Bridle we would always stop short to release. If the release failed we would break the weaklink.

How?

Most of you would not be able to do safely what I'm about to tell you because you fly gliders that can give you handling problems at high speeds and your weaklinks are too strong.

I don't tow with gliders that will do that.

My weaklinks are not too strong.

I put a vertical stabilizer on my glider for towing so that it will not handle poorly at any speed under the gliders V.N.E. (That's no out of control handling problems of PIO or DIO folks, at any speed below the gliders VNE.)

Now I'm able to radio the driver to break my weaklink by speeding up with me pushing out slightly. The weaklink breaks before I am in danger of a nose high stall and I fly away all the time with both hands on the basetube. We stop short on clear tow roads for the same option. (That was the third thing I use my weaklink for.)

The fourth thing I use my weaklink for is to break under a tension that will not allow my Skyting Bridle to snap the release strap back into my face.

How many of you have not put your weaklink onto your bridle and put each end over the ball hitch of two vehicles and pulled it until the weaklink broke to see what the bridle did? If you did that most of you would be changing your bridles.

It's my opinion that mandating the maximum strength of a weaklink is not crazy. A weaklink should be strong enough to do the job with everything else being done correctly from the weaklink forward. (Too much rope on a winch will make a pilot creep up on the strength of the weaklink too. The same with too much launch speed)

As for holding a release in my teeth, I'd like to have a look at one but it would have to release out beyond all of my flying wires and not snag even if I released late at 90 degrees to the towline.
http://groups.yahoo.com/group/hhpa/message/9426
Good news for ST/FL pilots
Bill Cummings - 2010/02/09 01:26

Resist the urge to reply- (I can't mind my own business.) I'm too weak!--Oh, darn here I go again! ---Sorry!

From a message on this board a while back a pilot mentioned that he didn't care to release due to his towline touching the front wires of his hang glider as he was trying to keep his glider under control (Possibly Scooter Towing). His concern was that the towline would whip around or capture a nose wire and put him in a serious lock-out situation. A very legitimate and, decades old, well thought out concern.

A release from behind your gliders rigging is not as safe as one outside of the gliders rigging. This was one concern that the Hewett Bridle answered by placing the release out beyond the gliders wires and control frame.

Sometimes trying to come up with a "better wheel," than the old one can reintroduce problems that had already been addressed earlier on.

Aero Towing brought back the threaded release bridles (from behind the gliders rigging.) that had been discarded twenty some years ago during the center of mass towing development.

The threaded bridles for Skyting and Aero Towing were capture prone and needed a back up. The answer then became a threaded shoulder strap to shoulder strap back up release.

So if you came off of the dolly funny and had to release you would be expected to trip the handle to release the top rope. If the release worked and it didn't catch any of the wires that go to the nose of the glider, didn't whip and capture at the ring at the end of the Aero Towline you were good to go ---almost. Next gather up the trailing bridle and stow it so that when landing it would not snag on the ground or you would not step on it while running out the landing. But lets say that the top rope did capture somewhere and you had to rely on the backup which was there just for this occasion. You release it and, if it doesn't capture itself as it unthreads, once again you are good to go.

Remember now this example was having you come off of the dolly funny and you were low and letting go of the control bar to activate one or both of your threaded releases. The "Katy bar the door," back up was the hook knife if both threaded releases captured. No added problem here, grabbing the knife with your free release hand, because you weren't steering anyway.

Many thought the "Pro-Tow" method would take care of all this drama.

The Pro-Tow was towing solely from the shoulder straps. (With a threaded release bridle inside of your gliders rigging.) If you had a glider with little pitch possessiveness but still enough to pass the non divergence test on the test truck you would be able to hold the nose down to keep your position behind the tug and hopefully not be too tired to fly once FINALLY released.

If at the point of release a thermal gusted you to one side make sure the towline doesn't capture a nose wire on the way out.

Now I not saying to use a Hewett Bridle to Aero Tow. (Although it would work as it will work with scooter tow, static tow, and launching off of a dolly. Water towing with it is not a good idea.) I'm just saying think about what you may be giving up when switching to new, and in this case a ridiculously expensive ($350.00) release without much history.

Will this body release be just as safe for any method of towing that you are doing? Will it be just as safe for Scooter Tow, Platform Tow, and Aero Tow?

I haven't seen this $350.00 release but at that price it had better, wake me up, dress me, drive me to the airport, and hook me up to the towline.

Will the method of release that you settle on answer the important safety issues that have been addressed in the distant past?

Ask Doctor Hewett to list for you the issues that need to be addressed for a safe tow flight.

If I still had his 25 year old newsletters I'd scan and post them.

Would that be copyright infringement?
Weaklinks, a different opinion.
Oh goodie. Just what we need. Yet another hang glider pilot's OPINION on weak links. Lemme delete some stuff from my hard drive to make room for it.
For now I'll leave Aero Towing out of the weaklink conversation.
Yeah, the aerotow weak link has totally different functions than the ones used for surface and, anyway, all the issues were settled twenty years ago.

- 1.0 Gs is the perfect aerotow weak link.

- But if you wanna be REALLY safe go with half that.

- A weak link of 1.0 Gs or less will always blow before you can get into a stall attitude, lockout, or too far out of position.

- A loop of 130 pound Greenspot on the end of either a two or one point bridle will put any glider at exactly 1.0 Gs.

- If anyone blows a loop of 130 pound Greenspot it's because he's not flying smoothly enough and needs more tandem training. (And for some very strange reason little girl student pilots on morning and evening training flights seem to be much better at flying smoothly on tow than six foot tall dudes flying competition in strong thermal conditions.)

- If a glider slams in shortly after launch and the weak link can't be found the reason the glider slammed in will be because the pilot accidentally doubled it (and the tug driver also accidentally doubled his).

- If a glider slams in shortly after launch and the weak link is known to be a single loop of 130 that data must be ignored.

- If you DO get into a lockout with a single despite the fact that it won't let you, just pitch out abruptly and all your troubles will be over.

- Anything over a single loop of 130 will instantly cause the glider to lock out, stretch the sail, and kill the pilot - even if the air's milky smooth and there's something lighter on the tug end.

- Anything over a single loop of 130 severely endangers the tug driver - even if the air's milky smooth and there's something lighter on the tug end.

- Unless it's on a tandem glider - then it's OK to double it.
Besides having a weaklink to protect the glider from breaking...
STOP. There is no fucking "BESIDES". Anything anyone says beyond that is totally moronic.

http://www.dynamicflight.com.au/WeakLinks.html
Dynamic Flight

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.
...it will also...
Oh boy, here we go...
...stop a glider from climbing into a nose high stall if it breaks at high speed under a lot of tension.
High speed. What the fuck is that? 25? 30? 35? 40?

Let's call it 25. So a weak link shouldn't be expected to blow under an airspeed of 25 miles per hour. OK.

A lot of tension. How much tension? Let's make the weak link 200 pounds.

If the glider's climbing fast with an airspeed of 35 miles per hour and the normal tow tension is 125 pounds will the weak link blow when the tension hits 150? 175? 190? Are we getting close?

If the glider's climbing slowly at an airspeed of 22 miles per hour and the normal tow tension is set to 150 pounds to what tension will the weak link hold? 175? 200? 225? 250? If we speed the glider up can we blow the weak link at 250?

For ten thousand dollars, Bill, what is your first name? Take your time and think carefully before answering.

So the weak link will stop a glider from climbing into a nose high stall if it breaks at high speed under a lot of tension.

That's SO reassuring to know! Just a few questions...

- Can the glider climb into a nose high stall:
-- if the weak link:
--- DOESN'T break at high speed under a lot of tension?
--- doesn't break at LOW speed under a lot of tension?
--- doesn't break at LOW speed under LOW tension?
-- at LOW speed under LOW tension?
-- at low speed under NO tension?

- What happens to the glider if it's already climbed into a nose high stall at moderate speed and a stupid anemic fucking 0.8 G weak link blows?

- Do the names Brad Anderson and/or Eric Aasletten mean anything to you? They both whipstalled and slammed into the runway after coming off tow under low controlled tension. The runway that Eric slammed into was at Hobbs. Hobbs is in New Mexico. You're in New Mexico. Explain that in the context of this total bullshit OPINION of yours concerning this purpose of the weak link.
(That was two things so far.)
Nah, that second thing was such a load of shit that I'm gonna knock you down to Negative Three.
A third thing I use a weaklink for is a back up for a release failure.
Yeah!!! The Voight/Rooney approach...
As for being in a situation where you can't or don't want to let go, Ryan's got the right idea. They're called "weak" links for a reason. Overload that puppy and you bet your ass it's going to break.

You can tell me till you're blue in the face about situations where it theoretically won't let go or you can drone on and on about how "weaklinks only protect the glider" (which is BS btw)... and I can tell ya... I could give a crap, cuz just pitch out abruptly and that little piece of string doesn't have a chance in hell. Take your theory and shove it... I'm saving my a$$.
(Hey Head Trauma, how come my ass just has esses and yours has dollar signs? Something to do with your "keen intellect"? Is that where your brains are?)
Many a time in the winter when snow machine towing we would run into frozen release problems with many different types of releases.
What kinds of releases? Anything NOT from the flappy string V kludge department?
Slush on the frozen lake would freeze at altitude.
Sure is a good thing there was no possibility of your release freezing up NOT at altitude.
Rather than let go of the control bar to cut the Skyting Bridle we would always stop short to release. If the release failed we would break the weaklink.
Yeah, that sounds like loads of fun.
Most of you would not be able to do safely what I'm about to tell you...
I think we left the adverb "safely" back on the other side of the Rubicon a long time ago - but DO continue.
...because you fly gliders that can give you handling problems at high speeds...
You're probably right. Hey, anybody got a Seahawk he'd like to swap for a T2? I'll throw in a racing pod and a Flytec 6030.
...and your weaklinks are too strong.
http://groups.yahoo.com/group/hhpa/message/11091
Al Hernandez - 2010/09/11 14:57

When doing a platform tow as soon as the vehicle reaches speed and the wind indicator reads 25 or 30 mph, the pilot pulls the release, and the glider starts to go up shouldn't the pilot be pulled in just in case the weak link breaks??????
Yeah, we're not nearly as afraid of them as we should be.
My weaklinks are not too strong.
GREAT!!! Do we get to hear anything about Gs or pounds? Just kidding, "not too strong" works for me.
I put a vertical stabilizer on my glider for towing so that it will not handle poorly...
Or, off of tow, well.
Now I'm able to radio the driver to break my weaklink by speeding up with me pushing out slightly. The weaklink breaks before I am in danger of a nose high stall and I fly away all the time with both hands on the basetube.
COOL!!! Most of the time you're gonna have everything under control and this saves you all the hassle and expense of the engineering to do it right.
The fourth thing I use my weaklink for is to break under a tension that will not allow my Skyting Bridle to snap the release strap back into my face.
A flappy string V kludge protector! Who'da thunk! One dangerous piece o' shit piece of towing equipment to mitigate another. And they say that two wrongs don't make three wrongs. Pffft. What do THEY know?
How many of you have not put your weaklink onto your bridle and put each end over the ball hitch of two vehicles and pulled it until the weaklink broke to see what the bridle did?
How many of you are using a bunch of flappy string V kludge in which something like this is the slightest issue? (By the way... Are you still using perlon to assemble your flappy string V kludge?)
If you did that most of you would be changing your bridles.
Yeah. Probably to a Spectra two point aerotow or Koch two stage configuration.
It's my opinion that mandating the maximum strength of a weaklink is not crazy.
In nobody's opinion is mandating a maximum crazy. If it doesn't blow before something else does then it's not the weak link.
A weaklink should be strong enough to do the job...
"THE" job? You really haven't discussed anything with respect to THE job. We haven't heard a single mention of Gs or pounds or what the glider can take.
As for holding a release in my teeth, I'd like to have a look at one but it would have to release out beyond all of my flying wires and not snag even if I released late at 90 degrees to the towline.
Typically when the glider's ninety degrees to the towline it's standing on its ear and the bridle's no nearer to any wires than it was when you started - unless you went to a lot of trouble to yaw it away from the towline. (John Woiwode would be the person to consult about how to do that.)
A very legitimate and, decades old, well thought out concern.
That, oddly, never seems to actually happen in real life - unless some idiot deliberately yaws away from the towline. Maybe the decades old concern really isn't any more legitimate than the one about backup suspension and isn't any better thought out than the "floating crossbar" design fad.
A release from behind your gliders rigging is not as safe as one outside of the gliders rigging. This was one concern that the Hewett Bridle answered by placing the release out beyond the gliders wires and control frame.
Yeah, the Hewett Bridle was super for addressing a bunch of totally imaginary problems and issues - at the expense of opening things up for some really deadly real ones.
Sometimes trying to come up with a "better wheel," than the old one can reintroduce problems that had already been addressed earlier on.
Yeah, too bad Donnell never figured that out when Bob Fisher shoved the Brooks Bridle under his nose in 1982.
Aero Towing brought back the threaded release bridles (from behind the gliders rigging.) that had been discarded twenty some years ago during the center of mass towing development.
Yeah, aero with its threaded bridles has been an unmitigated disaster for hang gliding. People are getting killed left and right because of bridle wraps and wire snags. When WILL this madness stop?
The threaded bridles for Skyting and Aero Towing were capture prone and needed a back up.
The better designed they were the less wrap prone they were. I've got five hundred bucks that say you can't get one of mine to wrap in five hundred tows.
The answer then became a threaded shoulder strap to shoulder strap back up release.
No. That was AN answer. That was a STUPID answer. That's what you get when you let a bunch of asshole pilots pretend to be engineers and start setting and enforcing "standards".

The not stupid answer was to use secondary releases coming off the shoulders to about a foot and a quarter out, run a secondary threading bridle through a thimble in the bottom of the primary, and make the secondary bridle so short and fat that it's NOT, in effect, a threading bridle - make it so's it CAN'T WRAP.
So if you came off of the dolly funny...
I'm trying to think of a half decent reason why anyone would come off of a dolly funny and I'm not coming up with anything. Yeah, if you do something stupid you can come off a dolly funny and kill yourself. Just like you can come off a slope, ramp, or cliff funny and kill yourself - it's just a whole lot harder to do coming off a dolly.
...and had to release you would be expected to trip the handle to release the top rope.
If you do the engineering that's not that B an FD.

http://www.flickr.com/photos/aerotowrelease/8306300488/
Image
If the release worked...
*IF* the release worked? The ONLY reason releases don't work is shitrigging. It ain't all that tough to design and build something that's gonna work a million out of a million times.
...and it didn't catch any of the wires that go to the nose of the glider...
Bullshit. Name:
- ONE instance in which there was a wire problem in which the towline was kept tight
- MORE THAN ONE instance in which there was a wire problem in which the towline was slackened
- ONE half decent excuse for allowing a slack towline
...didn't whip and capture at the ring at the end of the Aero Towline...
Bullshit.

- Name ONE crash resulting from a bridle wrapping at a tow ring.

- If you have a secondary weak link below the tow ring a little bit heavier than the primary there's virtually no freakin' way it's gonna survive the jolt.
...you were good to go ---almost. Next gather up the trailing bridle and stow it so that when landing it would not snag on the ground or you would not step on it while running out the landing.
Bullshit.
Name ONE instance of a trailing bridle snagging or tripping someone.
But lets say that the top rope did capture somewhere and you had to rely on the backup which was there just for this occasion. You release it and, if it doesn't capture itself as it unthreads, once again you are good to go.
I was gone a long time ago. See above.
Remember now this example was having you come off of the dolly funny and you were low and letting go of the control bar to activate one or both of your threaded releases.
Bullshit.
Who says you've gotta let go of the control bar to activate either one or - if it floats your boat - both simultaneously?
The "Katy bar the door," back up was the hook knife if both threaded releases captured.
Bullshit.
Even with everyone using the shitrigged equipment they do... Name ONE instance of BOTH bridles wrapping.
No added problem here, grabbing the knife with your free release hand, because you weren't steering anyway.
It's not such a bad thing to kill someone towing every now and then. Gotta think gene pool.
Many thought the "Pro-Tow" method would take care of all this drama.
- WHAT DRAMA??? So far this is just a bunch of crap you've dreamed up and isn't happening in real life.
- Bullshit.

NOBODY "Pro-Tows" to take care of this imaginary drama. People tow one point because they have gliders that do it easily and don't want or need all the extra hardware required to tow two. (They also tow one cause all the two stuff commercially available is draggy, chintzy, dangerous shit - but that's different can of worms.)
The Pro-Tow was towing solely from the shoulder straps. (With a threaded release bridle inside of your gliders rigging.)
BULLSHIT.

Image

The bridle's no freakin' way NEAR being inside the glider's rigging.
If you had a glider with little pitch possessiveness but still enough to pass the non divergence test on the test truck...
- Just how many gliders have you been seeing in the past thirty-some years that HAVEN'T passed the non divergence test on the test truck?
- Seeing as how in the US aerotowed gliders are required to be HGMA certified anyway...
...you would be able to hold the nose down to keep your position behind the tug and hopefully not be too tired to fly once FINALLY released.
Bullshit.
If the glider doesn't trim well enough to tow one point people don't tow it one point.
If at the point of release a thermal gusted you to one side make sure the towline doesn't capture a nose wire on the way out.
Bullshit.
- When a glider gets kicked off line by a thermal it ROLLS and locks out. The bridle stays centered.
- The bridle's also in front of and below the wires. See above.
Now I not saying to use a Hewett Bridle to Aero Tow.
Good. You'd be laughed out of the airport if you did.
Although it would work as it will work with scooter tow, static tow, and launching off of a dolly.
Gliders with backup suspension WORK - it's just that the backup suspension doesn't do anything and isn't there for a rational reason.
I'm just saying think about what you may be giving up when switching to new, and in this case a ridiculously expensive ($350.00) release without much history.
- You may and will be giving up a lot of flappy string V kludge that doesn't do anything useful, interferes with the basetube, and has vegged one pilot and killed two others when it's found something to snag on.

- Yeah, a high quality 350 dollar tow release which is gonna be used and an issue on every flight is ridiculously expensive but a nine hundred dollar parachute that you're never gonna use isn't.

- Without much history...
Skyting - 1985/06

Tony & Rona Webb

The tow system in Germany appears to be chest towing with a "V" line connected under and over the bar. The initial climb is towed over the bar with the "V" line under, slack. At a safe height, the first overline is released. A jerk is felt as the under "V" line takes up the tension. This system gives quite a nose-up quality that has become accepted as the norm in Germany. It is possible to release both over and under "V" lines together in an emergency.
Right. Besides, you always wanna consider the HISTORY of a piece of hardware and ignore the engineering and performance standards. You NEVER wanna be the first kid on the block to fly the latest model glider. Wait two or three years until lotsa other people have racked up hundreds of hours one them.
Will this body release be just as safe for any method of towing that you are doing? Will it be just as safe for Scooter Tow, Platform Tow, and Aero Tow?
I guess there's just one way to find out. It's not like we can predict anything from thinking and/or ground testing.
I haven't seen this $350.00 release but at that price it had better, wake me up, dress me, drive me to the airport, and hook me up to the towline.
How 'bout if it just keeps the bridle off of the basetube at all tow angles, functions quickly and easily under load, doesn't drag in the slush between tows, wouldn't freeze up and become totally inoperable at altitude even if it did, and isn't configured so you get a face full of flappy string V kludge every time you release or the weak link blows?
Will the method of release that you settle on answer the important safety issues that have been addressed in the distant past?
Yeah Bill, let's take a look at the distant past...
Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"Never take your hands off the bar." - Tom Peghiny
"The greatest dangers are a rope break or a premature release." - Richard Johnson
Just how well have those issues been addressed?
Ask Doctor Hewett to list for you the issues that need to be addressed for a safe tow flight.
Yeah let's take a look at how Doctor Hewett addresses the issues of a safe tow flight...
Donnell Hewett - 1982/06

It is our practice to follow the following procedure when hooking in. (1) Attach the keel latch. (2) hook the pilot in. (3) hang check, and (4) attach the body latch. The idea is to never attach the body latch until after the pilot is hooked in. Since the pilot cannot take off without attaching the body latch, this prevents him from attempting to take off without being hooked in.
Donnell Hewett - 1981/10

One last time you check the tail-tales on your glider to assure yourself that you are pointed into the wind with the nose angle high enough to catch the air on takeoff, and you make sure that your wings are level, that the glider is completely under your control, that your footing is secure, and that you are mentally ready to go. With a stomp of your foot you are committed.
Donnell Hewett - 1985/04

I - yes, I, too - have failed to hook-in on tow launch, but I never kept holding on to the glider when it lifted off without me.
Donnell Hewett - 1983/03

Instead of holding the nose down as I had promised, I picked up the glider, lifted up on the control bar and let the glider start to climb. It climbed about three feet and then apparently stalled. The left wing dropped down and hit the sand and of course, at that point, I no longer had any control over the situation. The wind continued to lift the high wing until I was looking straight down the other wing toward the ground 25 feet below. I then came crashing down on top of the glider as it continued to roll upside down.

Needless to say, I hit pretty hard, but the glider took much of the impact and the sand on the beach was at least somewhat forgiving. Nevertheless, I broke my arm just below the shoulder. Fortunately, no other damage was done except for the glider. There I broke one leading edge, both down tubes, the forward keel, and several battens.
Scott G. MacKnight - 1983/09
Price, Utah

Suddenly, at about 150 feet, the airspeed increased dramatically and I was climbing like a rocket. I thought it must be a wind gradient so I pulled in to get that high nose angle down and told Dave to slow down. What?, airspeed still increasing! "Slow down, Dave!". "Dave, slow down!". DAVE!!?? "STOP!!!". I looked over my shoulder at the radio and discovered a problem, the microphone cord had snagged on something and pulled loose from the radio, well that explains why Dave was happily speeding down the road while I was having such an exciting time. Now I was really getting high and Dave was showing no signs of slowing, so I decided it was time to do something. "Oh yeah!", I thought, "How about releasing? Good idea!" Then I noticed that the tow angle had steepened, the release line tied to my wrist had developed a good bit of slack. I took my hand off the bar to try to release. No good! Too much slack! My left hand wasn't strong enough to keep the bar at my knees so the bar immediately came up to my chin. I grabbed the bar again and stuffed it.
Lindsay Fischer - 1983/10
Colorado Springs

The only problem we are having is the weak link. We are breaking too many. But I am afraid to strengthen them. Safety first. Our problem is not having a tension gauge on the rope. That, I think, is an essential. Otherwise, the driver is at sixes and sevens all the time. We just tell them to drive up crisply to 25 mph and hold it there. This works about 50% of the time. The rest of the time we are breaking something.

The other day my boy towed me. The usual. The start was too fast: the weak link broke at fifteen feet up: I stalled; and on coming down I bent another bar. At $20 per bar to replace this gets rather old.
Donnell Hewett - 1983/07

Don't try so hard to make a short takeoff. I know you are familiar with "pop starts" and do not want to increase the chances of a poor takeoff by making a long run. Furthermore, you are wise to try to stay with what you know. But skyting is more like conventional foot launching, where you begin by gently running off a hill, not by jumping off a cliff. After you master the gentle takeoff you can perfect your short takeoff technique.
http://ozreport.com/forum/viewtopic.php?t=21649
Truck Towing Accident in South Texas
Gregg Ludwig - 2010/10/28 15:46:59 UTC

Here is another report from a student (H-0) that may shed some light on the methods of instruction used. This student weighs about 250 pounds and was using a glider too small for his first tow over asphalt as reported.
28th and 29th I will be up in Kingsville, at the Kleberg County Airport about 8 am. I will be training with the Doc. He will be having lessons there Saturday, depending on weather conditions. Will be towed up with a winch - this will be my first tow. Have just been doing foot launch, will get some airtime in on those days.
...
I had to stand like a post, and not move at all once the truck took off at 25 mph with one foot in front of the other, and I am still standing in the same place leaning back, with the payout feeding me line, and there is a strange feeling, odd feeling to being pulled by the payout.

Then I take the first step to the run, and I am now running 25 mph, I am thinking, oooOOOOH SH#T, hope I don't have to run that far, hoping the HG gets lift so I don't have to run no more... My F-A running down the runway like a rocket. There is no wind, I have the right angle of attack, the HG is up, but still not enough lift for the pilot.

I can't reach my CUT line 'cause I have both hands on the downtubes, and if I let go of the Coke bottle grip I will crash.

I feel like pushing the HG into the air, or jumping up so it can lift, but I do not - that would make my situation worse.

I feel I am about to fall into the asphalt face first and crash, I am at my run limit, and feel I can not take another step. Still the glider is not lifting me.

The winch operator lets go of the pressure of the payout winch, my run comes to a jog, and to a stop. I drop to my knees.
- Never connect to the towline until you're hooked into the glider. That way any time you're connected to the towline you can assume you're hooked into the glider.

- Never verify that you're hooked into the glider the instant before you're "committed" to launch. The last thing you should do before you "commit" to launch is stomp your foot.

- If you're a launch assistant or driver you should assume that any pilot connected to a towline is also connected to his glider - especially when he stomps his foot.

- Configure the release so the actuator is someplace where you won't hit it accidentally after you commit to launch. When a good pilot commits to something he sees it through - no matter what.

- Always use a tension gauge. As long as the tension is constant the glider can't possibly get into too much trouble.

- Never use a weak link over one G. That way the tension can't possibly vary too much above normal tow tension and - as has just been made perfectly clear - if the tension never gets much higher that what you're normally shooting for, the glider can't possibly get into too much trouble. It doesn't matter how many times you stall and crash when the weak link blows - just remember that if it hadn't blown you might have locked out and died. Never compromise safety for the sake of safety.

- Always use a radio. Reliable communications are very important for safe towing.

- Starting off on asphalt is good because it's a smooth surface and you get good traction for your launch run.

- Under no circumstances utilize a launch dolly - hang gliding IS foot launched aviation after all.

- Avoid pop starts AT ALL COSTS. It's extremely dangerous to just blast into the air like people do off of dollies and platforms because the pilot really doesn't have good control of the situation. A nice long run with GRADUALLY increasing increasing speed and tension is best.
If I still had his 25 year old newsletters I'd scan and post them.

Would that be copyright infringement?
I sure hope not. This is WAY too much fun.
llwest@comcast.net
Posts: 18
Joined: 2011/01/26 14:30:47 UTC

Re: Video of surface tow, foot launching with Hewett bridle

Post by llwest@comcast.net »

Tad Eareckson wrote:
It was worrisome to me, but his father (a master rated pilot and advanced instructor)...
Bill Cummings?
No, Mel Glantz (http://nmhanggliding.com)
Gregg Ludwig is coming out next weekend to teach me what he knows.
Anything I should be expecting him to say that will make me scream?
I'll stifle my scream to get his approval, but I imagine you know these guys a lot better than I do.
User avatar
Tad Eareckson
Posts: 9149
Joined: 2010/11/25 03:48:55 UTC

Re: Video of surface tow, foot launching with Hewett bridle

Post by Tad Eareckson »

Mel...

Yeah, I could've figured that out easily enough if I had gone to the USHGA website. Amazing, though, that you still have at least three Hewett disciples still in circulation down/out there.

Gregg...

While he IS on the short list of hang glider people I don't totally despise (I was actually a bit upset when he was reported missing in action for a while last fall) he doesn't really know what he's talking about and doesn't stick around in the conversations long enough to fix that.

Probably won't say anything that makes you need to stifle a scream, though. Put him in the "mostly harmless" category.

Thanks for breaking up the monologue with the first non-Tad post in a week. Now... Back to the monologue.
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