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Hang Loop Question

Postby AirNut » Mon Dec 15, 2014 1:42 pm

Hi All,

I've just taken delivery of a crispy brand new Falcon 4 170 :D :D :D :D

But the snag is that I'm in Australia and have an Australian harness, so I've got the usual issue with the length of the hang loop (about 8 inches too short). I've got a replacement arriving from Wills Wing in a few days, so no drama there. But I do have a few questions about this.

This is the first WW glider I've owned (all my others have been Aussie brands). On all my other gliders, there's been some sort sort of retaining mechanism that fixed the hang loop in place, but on the Falcon, the hang loop is only secured by friction, i.e. being cinched tight enough to avoid shifting in flight (as described in the manual - see attached image). This strikes me as being just a little dippy.

hang_loop.jpg
hang_loop.jpg (96.46 KiB) Viewed 4216 times


Am I being a bit paranoid about this? How do you know if the hang loop is tight enough short of flying and finding out the hard way? The manual says "very tight", but how tight is very tight?

Has anyone out there installed/replaced a hang loop on a Falcon or other WW glider?

Thanks!
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Re: Hang Loop Question

Postby Rick Masters » Mon Dec 15, 2014 2:20 pm

Am I being a bit paranoid about this?


I don't think so. The worst place to ever find your cg/hang point has changed is in violent air. I used to tape down my hang straps with strong reinforced fiberglass tape with several wraps around the keel.
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Re: Hang Loop Question

Postby Bob Kuczewski » Mon Dec 15, 2014 3:12 pm

I bought a new Falcon 195 in 2008, and I've never had a problem. The hang point (at least on my model) is pretty well constrained by a keel pocket in the front, and the kingpost/control frame mounting in the back. So it can't wander too far.

Speaking of that, I was given a double surface glider a number of years ago from a good friend who was running out of storage space. I flew it in the mountains a few times and never had an issue. Then I took it to the smooth air Torrey Pines and had a shocking discovery. In the mountains, I almost always hold in a little extra speed for added control. It's an instinctive habit. But in the smooth air at Torrey, I felt comfortable letting the bar just float at trim. As I did that, the glider slowed (of course), but then it suddenly had a noticable stall break!!! In other words, the glider was trimmed in a stall!!!

It was still perfectly flyable, but I landed as soon as possible and adjusted the trim forward just the same!!
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Re: Hang Loop Question

Postby wingspan33 » Mon Dec 15, 2014 6:01 pm

Air Nut,

I don't think this is a bad hang loop securing design. But that doesn't mean you can't customize it to suit your interests.

But before going that far, if you KNOW you need to change the position of the hang loop, . . . then follow the directions (with common sense) that WW includes in the manual. Then, what I would do is, hook into the hang loop with my harness (glider set up in the back yard) and YANK the heck out of the re-installed hang loop. Does it move? If so, then you haven't got it tight enough! lol

Wills Wing's designers/engineers have determined that the their "cinching" system works - or they wouldn't let the system ship out.

Now, all that being said, Rick Master's comments about wrapping the strap with reinforced tape is one way to modify the hang loop - to your personal preference. I would look into some method of sewing the straps together in the tight setting (using heavy Dacron/polyester thread). Or, a little "Super Glue" could also adhere the straps once they are tightened (not sure of how good this suggestion is - proceed on your own risk here).

In the end, personally, I would go with the idea at the top of this post. Change things (one way or the other) if you are not satisfied. Last resort, . . . Call Wills Wing! :)
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Re: Hang Loop Question

Postby Bill Cummings » Mon Dec 15, 2014 6:46 pm

Gliders that I have owned in the past also had a friction strip (Bath tub type stuff) on the keel top but that was never good enough for me.

I also didn't trust the keel pocket stitching to keep the hang strap from sliding to the nose by stripping out the keel pocket stitching and finally stopping when it was against the nose plate after a possible tumble.
My fix was to tie the hang strap to the heart bolt, king post, or top of the "A" frame so that it couldn't move forward.
Usually it can't slide back far enough until it stops against the A frame, Heart bolt, or king post anchor to give you any trouble that you couldn't handle with weight shift to keep it from stalling.
Sliding backwards is not serious but moving forward could be.
Older gliders hung sometimes behind the A frame. I tied them too so that they couldn't slide back and cause problems.
I used my common sense to remedy other poorly thought out design ideas like the keyhole tang being secured by a rubber retainer which was later subject to a technical advisory. I never took flight with a rubber retainer but instead put a safety ring through the larger hole of the keyhole tang so that it couldn’t unhook from the anchor lug.
Later design came out with two different ways to block the keyhole tang from becoming unattached.
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Re: Hang Loop Question

Postby JoeF » Mon Dec 15, 2014 7:33 pm

Hang-loop considerations:

1. When the hang loop is clinched on a friction base, movement is unlikely.

2. It is when a hang loop is under no active load that one might consider how untightening might occur and inadvertent movement of the hold position might occur. When the hang loop has been in storage, just how much relaxation of "tight" occurs? Then inadvertent push or pull during handling, unpacking, opening, etc. might move a relaxed clinch and not be noticed. Having a positive secondary position-keeping tie would address such matter.

3. I put up a red flag on the stitch-at-tight or the glue-at-tight idea; Creep during tensed "tight" may occur and one might end up with a stitched relaxed hold or a glued-relaxed hold. Such stitch or glue might prevent flight loads from keeping the hold tight. Secondarily, be very sure that stitching or glue does not bring on a long-term injury to the fibers of the hang loop. Consider the matter very carefully before going to a stitch or glue situation. My vote is a no on such.

~ JoeF
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Re: Hang Loop Question

Postby AirNut » Mon Dec 15, 2014 7:45 pm

wingspan33 wrote:Air Nut,

I don't think this is a bad hang loop securing design. But that doesn't mean you can't customize it to suit your interests.

But before going that far, if you KNOW you need to change the position of the hang loop, . . . then follow the directions (with common sense) that WW includes in the manual. Then, what I would do is, hook into the hang loop with my harness (glider set up in the back yard) and YANK the heck out of the re-installed hang loop. Does it move? If so, then you haven't got it tight enough! lol

Wills Wing's designers/engineers have determined that the their "cinching" system works - or they wouldn't let the system ship out.

Now, all that being said, Rick Master's comments about wrapping the strap with reinforced tape is one way to modify the hang loop - to your personal preference. I would look into some method of sewing the straps together in the tight setting (using heavy Dacron/polyester thread). Or, a little "Super Glue" could also adhere the straps once they are tightened (not sure of how good this suggestion is - proceed on your own risk here).

In the end, personally, I would go with the idea at the top of this post. Change things (one way or the other) if you are not satisfied. Last resort, . . . Call Wills Wing! :)


Just to clarify, I wasn't seriously questioning WW's design by any stretch. ;) I have great admiration for their professionalism and experience (which is why I've just bought a Falcon after a couple of decades of buying Aussie gliders). I imagine that it's so designed that adding weight will tend to cinch it even tighter on the keel. As I mentioned earlier, it's mostly a paranoia thing, but also just to have everything 'squeaky clean' so to speak. And also to mitigate against me stuffing up somehow when replacing the loop (much more likely than WW buggering up).

But I'll certainly be taking your advice and do the ground-based stress test and make sure that nothing shifts. And obviously, first flights on the training hill.

Thanks for all the replies everyone.
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Re: Hang Loop Question

Postby AirNut » Mon Dec 15, 2014 8:04 pm

JoeF wrote:Hang-loop considerations:

1. When the hang loop is clinched on a friction base, movement is unlikely.

2. It is when a hang loop is under no active load that one might consider how untightening might occur and inadvertent movement of the hold position might occur. When the hang loop has been in storage, just how much relaxation of "tight" occurs? Then inadvertent push or pull during handling, unpacking, opening, etc. might move a relaxed clinch and not be noticed. Having a positive secondary position-keeping tie would address such matter.

3. I put up a red flag on the stitch-at-tight or the glue-at-tight idea; Creep during tensed "tight" may occur and one might end up with a stitched relaxed hold or a glued-relaxed hold. Such stitch or glue might prevent flight loads from keeping the hold tight. Secondarily, be very sure that stitching or glue does not bring on a long-term injury to the fibers of the hang loop. Consider the matter very carefully before going to a stitch or glue situation. My vote is a no on such.

~ JoeF


I agree with you there, Joe. That might be a case where the cure might be worse than the disease!

On a tangent: one of the things that I love about hang gliders as aircraft is their simplicity. It's comforting to know that you can touch/see/inspect virtually every square inch (try doing that on a Cessna, or even a sailplane). Generally, we should assume that the manufacturer knows best and not monkey with things (at least without being very careful or checking with the manufacturer first).

Following that thought, a short anecdote: Back-in-the-day at one of our local sites (Lake George), we had a guy who thought he'd experiment a bit with the design of his glider (without the manufacturer's knowledge). This guy (to remain nameless) reasoned that his glider would roll quicker if he added a bit more anhedral to the wings. He achieved this by cutting a couple of foot-square holes in the sail and inverted the cross-bar leading edge junction, i.e. he connected the cross-bar BELOW the leading edge instead of ABOVE (this was in the days when the two tubes were bolted together manually on either side of some plastic saddles).

He figured that this would add 2 inches of anhedral and speed up his roll rate. In this he was completely correct as he soon found out by taking off at Lake George (no training hill fight first) and then doing a series of unintentional wing overs down to the landing area. :shock:
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Re: Hang Loop Question

Postby Bill Cummings » Mon Dec 15, 2014 10:36 pm

Crossbar BELOW :? or crossbar above?
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Re: Hang Loop Question

Postby Bob Kuczewski » Tue Dec 16, 2014 2:56 am

billcummings wrote:Crossbar BELOW :? or crossbar above?

That seemed like it might be reversed to me as well, but it might be a matter of reference.

By the way, this has just become my second favorite topic on the forum (just behind "Hello US Hawks!!").

Who'd have thought that people in a hang gliding forum would actually talk about ... hang gliding?    :crazy:

A BIG THANKS to AirNut, RickMasters, wingspan33, billcummings, and JoeF for a great exchange of thoughts!!!

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