Notes for new hang glider pilots--Before you order a new Wills Wing harness...

Notes for new hang glider pilots--Before you order a new Wills Wing harness...

June 12, 2006 edition
Steve Seibel
steve at aeroexperiments.org
www.aeroexperiments.org

 

Before you order a new Wills Wing harness, I suggest you consider specifying a “DHV-length” main harness strap rather than the longer Wills Wing-length main harness strap.

 

Wills Wing hang gliders have larger control frames than many other hang gliders, so a harness with a long main strap allows the carabiner to be relatively close to the glider’s keel, so that the hang loop running between the keel and the carabiner can be relatively short.  The Wills Wing standard for the distance from the hook-in point to the base bar is 55 inches, and in this article, by “Wills Wing-length main harness strap”, we mean a main harness strap that is sized to give 1 to 2 inches of clearance above the control bar in this situation, as described on the Wills Wing website.  The DHV standard for the distance from the hook-in point to the base bar is roughly 48 inches, and in this article, by “DHV-length main harness strap”, we mean a main harness strap that is sized to give 1 to 2 inches of clearance above the control bar in this situation.  Clearly, the DHV standard is configured around either a smaller control frame, or a longer hang strap, than the Wills Wing standard, and in actual practice, most gliders from other manufacturers have smaller control frames than Wills Wing gliders do.  So far, so good.  The problem comes when a pilot wants to use his Wills Wing harness with a non-Wills Wing glider.  It’s been my experience that when a harness with a Wills Wing-length main strap is combined with a non-Wills Wing glider, in order to give the pilot adequate clearance above the control bar, the caribiner has to be only two or three inches below the keel of the glider.  It’s not easy to find a hang loop this short!  I’ve had this problem when flying gliders with a hang point on the keel (e.g. Pacific Airwave 9m Pulse, Aeros Discus 14) and when flying gliders with a kingpost hang point (e.g. Laminar MastR 12, Airborne Blade 132).  This issue was particularly aggravating when I visited the Quest Air and Wallaby Ranch tow parks in Florida—I had the opportunity to fly many different gliders, but it took hours of scrounging to find hang straps short enough to allow my harness to work with them.  The gliders with kingpost hang points usually posed the greatest challenge, because they required a more specialized style of hang strap.

 

If you do own a harness with a Wills Wing-length main harness strap and you plan on going to a place where you’ll have the opportunity to fly many different gliders, it would be an excellent idea to plan ahead and bring some extra-short hang straps along, including ones suitable for kingpost hang points.  Or borrow a harness with a DHV-length main harness strap for the duration of your trip.

 

With flex-wing gliders, this issue may be of more concern to small pilots than to large pilots.  Most of the flex-wing gliders listed above are relatively small, and the larger-sized versions of the same gliders come with slightly larger control frames.  With the slightly larger control frames, it would be slightly easier to make a Wills Wing-length main harness strap work.

 

Making exotic twists or double-loops or triple-loops in hang straps to shorten them can be dangerous.  Shortly before I entered the sport, the leading instructor in my area was killed due to a mistake in hooking in to a complex hang strap arrangement of this kind.  The caribiner appeared upon cursory inspection to be hooked into the hang strap, and the hang strap held the caribiner in place for a few seconds due to friction, but topologically speaking, the caribiner was completely unconnected to the hang strap, and after the multiple loops pulled through the caribiner, the pilot fell.

 

When a friend recently offered to let me fly his ATOS rigid-wing hang glider, I found it completely impossible to use my own harness with its Wills Wing-length main strap.  Rigid-wing gliders are typically made with quite small control frames—with their effective aerodynamic (spoileron or aileron) roll controls and slender wing chords, the extra roll and pitch control authority that comes from a low-hanging pilot simply isn’t needed—and my Wills Wing harness simply wouldn’t fit.  Fortunately, my friend and I were similar in size, so I ended up borrowing his High Energy harness along with his Atos.  Later I flew another Atos with another friend’s older Wills Wing harness.  (Note that while Wills Wing’s website states that they have standardized the distance from hook-in point to base tube at 55 inches since 1973, it is in fact the case that many older Wills Wing harnesses are configured with main harness straps that are significantly shorter than this standard would suggest.)

 

In summary, I think it may not be a good idea to order a new harness with the current standard Wills Wing-length main hang strap, especially if you are a smaller person who will be flying smaller gliders.  It’s always easier to fit a longer hang strap to a hang glider than it is to fit a very short hang strap to hang glider, and with rigid-wing hang gliders there may not be enough room to fit a Wills Wing-length harness strap even with the caribiner right up against the keel of the glider.

 

There’s only one large caveat to all of this advice: if you are buying a harness like the Wills Wing Z5, with several different suspension lines that run up to the caribiner instead of a single main harness strap attached to a long, solid backplate, decreasing the length of these suspension lines means that they will end up meeting the harness at a more acute angle (i.e. they will be less vertical), which can decrease comfort.  For example, the Wills Wing website states “We’re happy to accept a harness order for a Wills Wing made harness that specifies DHV length main supports.  However, you need to be aware that shortening the harness suspension length makes the angle of the front to rear suspension lines more acute, putting increased pressure on the shoulders, and measurably compromising the comfort of the harness.  This is not a factor on a harness with a solid backplate, but on a “soft” harness such as a Z5, the shorter mains reduce harness comfort to a significant degree.”  Elsewhere on the Wills Wing website, one reads “We strongly recommend that you size your [Z-5] harness mains to fit a standard Wills Wing hang loop.  Shorter main lengths are available on request, but they increase back compression and discomfort.”  So... what to make of all this?    My Wills Wing Z-5 harness is extremely comfortable and I would hate to do anything that would compromise this.  However, shorter-than-average people who are ordering smaller-sized harnesses should keep in mind that their front-to-rear suspension lines will naturally be slightly less acute than those of longer harnesses.  I think that these people in particular should strongly consider ordering a harness with a DHV-length main strap, even if they are currently flying a Wills Wing glider.  As for myself, I’m waiting for the chance to fly in a Z5 harness with a DHV-length hang strap for a good 6-hour flight, to see if I find the comfort level is any less than the excellent comfort that I experience with my own Z5 harness with the Wills Wing-length hang strap.  If not, I’ll eventually have my own harness modified to the DHV standard, because I value the chance to fly gliders other than my own--an Airborne Blade 132 specially fitted with an extremely short hang strap.

 

While we’re discussing harnesses, I’ll give a few more pieces of advice.  First, in my opinion a front-mounted chute greatly increases safety, and during a blown launch, I was once saved from a heavy blow to the chest from a large rock by the chest-mounted chute of my Wills Wing Z5 harness.  Second, before ordering a new harness, find a way to try one on of the same make and size, with all your flying clothes and with all your glider bags.  My impression is that many people tend to end up with a harness that fits great when the pilot is wearing street clothes and has no bags in the back, but is a bit tight when the pilot is suited up for high-altitude or cold-weather flying and has all his glider bags packed into the harness.  I nearly always fly with all my glider bags and several jackets, and I prefer not to have to re-arrange the velcro near my harness zipper to expand the harness to get a good fit in this situation, even if this means that my harness is a bit loose on the rare occasions when I am flying without my gliders bags and with minimal warm clothing.  If you live somewhere warm, rarely climb to high altitudes, and make a lot of local aerotow flights (or top-landing flights) without your glider bags, this advice won’t apply to you.

 

 

Some of these issues are addressed on the Wills Wing web site at the following links:

 

“How to get the right hang height” (including a section entitled “Ordering a Wills Wing harness with DHV length mains”)

“Z5 Hang Gliding Harness—Sizing and Ordering Information”

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