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By red
#402123
Lazypilot wrote:after all there's no one competing with them using a design that resembles, in a fashion, the Red Tail Hawk. So I guess God and Evolution don't know what they are doing, Their designs have straight wings, that don't couple washout with pitch stability, no, they have a tail.
Campers,

Yep, pitch stability by sweep angle means that a lot of wing area is used for stability, that could be better used for lift. In the attached picture, I think we got close, but we simply did not pursue the concept far enough. Now if you could use a slider-grip on the basetube to raise the washout tube on the inside of a turn, you could have power steering. If you raised both washout tubes at once, together with a strong dive command, you'd have some respectable (and retractable) glide-path control without using drogues, spoilers, or flaps. Of course, if the turning controls were to fail somehow, you'd still have a weight-shift controlled glider.

And heaven forbid, but we would not have the risk of short keels putting a wall in front of a prone pilot, in a whack. The longer keel would be much safer, then. In a serious whack, the pilot would swing up into the sail, not down into the dirt.

We were so close, so close . . .
. . . 8)
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By winDfried
#402126
red wrote: Tue Jan 30, 2018 11:37 pm...And heaven forbid, but we would not have the risk of short keels putting a wall in front of a prone pilot, in a whack. The longer keel would be much safer, then. In a serious whack, the pilot would swing up into the sail, not down into the dirt.

We were so close, so close . . . . . . 8)
And we still are:
http://www.bautek.com/index.php/astir-en.html

:) W.
By Goonie
#402127
Bowsprit + deflexors?

Other than drag concerns, why did this design fall out of favor?
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By red
#402129
Goonie wrote: Wed Jan 31, 2018 4:35 amBowsprit + deflexors? Other than drag concerns, why did this design fall out of favor?
Goonie,

The glider pictured (Aolus) had a reputation for excessive yaw, but it seemed to fly very well with an experienced pilot. I was flying an Albatross (ASG-21) then, so I was not concerned about the yaw issue anyway; I'd have little problem there. I did not have the money to buy an Aolus, so I never flew one, but I really liked that planform. There was a lot of promise in that first design. I still wanted larger tailplanes, to tame the yaw tendencies, and a wider nose angle, to better match the soaring birds. I see no need for deflexors, though, because they do cause serious drag at higher speeds.

A bowsprit can be a hassle to assemble in the field, but the Stratus V bowsprit gliders got it right; the bowsprit just pivots open at the noseplate with one bolt. In the HG design world, R&D means Rip-off and Duplicate. :lol:

WinDfried,

The Bautek Astir is indeed a viable bowsprit glider, but it's a baby step, when compared to the Aolus planform. I do appreciate the added safety of any bowsprit, in a mishap.
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By TjW
#402131
red wrote: Wed Jan 31, 2018 10:23 am I see no need for deflexors, though, because they do cause serious drag at higher speeds.
Absolutely with you on deflexors. The difference in weight between 1 1/2 x .049 tubing with deflexors and the large diameter thinner wall tubing is likely in favor of the larger diameter tube once you take into account the weight of the wire, turnbuckles, bolts and tangs.
It would be interesting to see what kind of performance a modernized Stratus V using 7075 large diameter tubing, mylar supported LE and defined ribs would have.
And what it would weigh.
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By raquo
#402143
I've been thinking along the same lines. You could even make the bowsprit topless, with struts like NorthWing's Freedom X.

If anyone has any comments on the aerodynamics of replacing sweep & washout by a close coupled tail like on this Aolus, I'd be very interested to hear those. For instance, would that compromise spin resistance, make stalls sharper, make the glider more side-slippery? Curious about the tradeoffs here.
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By red
#402150
raquo wrote: Thu Feb 01, 2018 1:53 amI've been thinking along the same lines. You could even make the bowsprit topless, with struts like NorthWing's Freedom X.
If anyone has any comments on the aerodynamics of replacing sweep & washout by a close coupled tail like on this Aolus, I'd be very interested to hear those. For instance, would that compromise spin resistance, make stalls sharper, make the glider more side-slippery? Curious about the tradeoffs here.
Raquo,

I believe that our own NMErider here has some pix and history of a HG design that is similar to the Aolus, called the White Tailed Dart. I would invite his participation here. 8)

The same invitation is extended to any Aolus pilots, of course.
By Lazypilot
#402154
I'm another pilot that agrees with Red that this glider design was pointed in the right direction (no, not down, that's just the way it's parked in the photo).

i just read the posts about the pilot who crashed in Colorado. The report tells us that he made a wrong move that placed him in an area of turbulence. It tells of him trying to correct, or reverse a turn he was in, but as many have experienced he needed both hands to muscle the glider and at the same time he needed to release the VG. It's hard to do, although he desperately needed more control authority he also likely felt the need for as much performance as he could get. I've felt for a long time that HG's really oughta have a foot-actuated VG, one that wouldn't require the pilot taking hands off the control bar to operate it.

Just bend your knees and go loose, straighten out your legs to tighten. Go loose to wrestle your wing into a thermal, get it centered and then tighten up so your anhedral can assist you in staying in, if she overbanks ease off the VG and let dihedral help you level off. Once banked up, you could quite literally core that baby without having to shift your weight at all, just vary the dihedral and let that ever-present adverse yaw no longer be considered "adverse", it would be your friend.

The Sport 2 155 that I flew was very responsive to the VG in the area of roll stability. If a glider were to be designed with this goal in mind, right from the git-go, it could make for much easier handling.

But back to the ranch. I have to say again that the necessity of a VG is an indictment of our decision to use weight-shift and weight-shift only as our sole means of roll control. I do believe that weight-shift is a good idea for some aspects of pitch control, but the industries failure to recognize that it is an inadequate way of steering anything other than a single-surfaced billow cruiser is borderline criminal. We've been told over the years that competition wins drive glider sales, and since the competition ruling bodies decided back in the 1970's that we would fly in Class 1, where weight-shift with no help from any kind of extra device would be the only way to turn the glider, the 99% of Hg pilots that don't fly in contests have been bearing the burden of that decision ever since. How many unexplained deaths can be directly attributed to a roll responsiveness that is at best pitiful, and totally unacceptable to any sane person.

I've had the holy S*it scared out of me many times since the Comet came on the scene in 1980 or whenever it was. Those scares needn't have been, and I must shamefacedly admit right now in front of God and everybody that I, and I alone, are responsible for who knows how many scary moments that pilots the world over have had to endure, and God only knows how many serious crashes and injuries and yes, fatalities, all because I just went along to get along.
I'm no longer going to remain silent. By remaining silent instead of rallying the troops I've been complicit, when maybe, just maybe, I could have been instrumental in making our form of aeronautical recreation better.

We call it a "sport", and athletes like sport, and I've noticed that they like to work out and sweat a lot. Fine for them, they can make their entire 10 hour XC with full VG all the way, and get their workout and sweat a gallon in the process.

On the other hand there are pilots like me who want complete control of their glider at all times, and don't want to have to fight for it.

Let me encourage those satisfied with the status quo to notice that it's me authoring a post to this fine site, and take the appropriate action of skipping my comments. I'm not interested in offending anyone, I only want to voice an opinion, an opinion I realize not everyone shares. I speak up to encourage others that do see it like I do to voice their feelings also.

The worst case scenario for me would be to find that I'm the only one who feels the way I do, in which case I'll quietly fold my tent like an Arab and silently sneak away.

I honestly don't know what the answer is, but I'm hoping that discussion of this matter will eventually reveal the answer.
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By red
#402155
Lazypilot wrote: Thu Feb 01, 2018 3:59 pm I'm another pilot that agrees with Red that this glider design was pointed in the right direction (no, not down, that's just the way it's parked in the photo).

I've felt for a long time that HG's really oughta have a foot-actuated VG, one that wouldn't require the pilot taking hands off the control bar to operate it. Just bend your knees and go loose, straighten out your legs to tighten. I have to say again that the necessity of a VG is an indictment of our decision to use weight-shift and weight-shift only as our sole means of roll control. I do believe that weight-shift is a good idea for some aspects of pitch control, but the industries failure to recognize that it is an inadequate way of steering anything other than a single-surfaced billow cruiser is borderline criminal. We've been told over the years that competition wins drive glider sales, and since the competition ruling bodies decided back in the 1970's that we would fly in Class 1, where weight-shift with no help from any kind of extra device would be the only way to turn the glider, the 99% of Hg pilots that don't fly in contests have been bearing the burden of that decision ever since. How many unexplained deaths can be directly attributed to a roll responsiveness that is at best pitiful, and totally unacceptable to any sane person.
Lazypilot,

Agree entirely, on the subject of competition rules.

I have even heard tell of electric-powered VGs, but I'm not convinced that any VG system is essentially good.

To me, after decades of flying the Fledgling, the real answer is power steering. With both rudders deployed, and all of that drag above your head for the moment, you get a huge pitch-up response by the glider. More than a few times, I was pitched out of a thermal in what should have been a nose-down-vertical dump. With any flexwing, you can only do two things then: hang on, and maybe pray. With the Fledgling, I soon had a solid automatic response to any dump-out: pull both sliders together. With both rudders fully out, the glider would descend in a 45 degree dive, holding that attitude while regaining forward speed. It was cake to let the rudders come back in smoothly, as the airspeed increased. I do not believe my Fledgling keel ever got vertical in a dump-out, and it certainly never went past vertical. The stock Manta basetube controls (twistgrips) were terrible, and most Fledgling pilots soon changed them for sliders. I believe that you could get much the same benefits by lifting both washout tubes at once on a flexwing, using basetube slider controls. Using only one slider, you would have simple, cheap, and effective power steering.

I believe the stupid competition rules have blocked many advancements in HGs for far too long now. I also believe that when every contestant shows up with power steering on their glider, those boneheaded comp rules from the distant past will collapse into the trash bin, which is where they belong.

All IMHO, of course.
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By NMERider
#402161
red wrote: Thu Feb 01, 2018 12:11 pm...I believe that our own NMErider here has some pix and history of a HG design that is similar to the Aolus, called the White Tailed Dart. I would invite his participation here. 8)...
Fun glider with good performance and handling. Would be fun to rebuild from modern 7075-T6 and laminate fabric and get rid of some wires too.
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By Lazypilot
#402164
A beautiful specimen of the aeronautical art. It's wonderful that you can do that. Tell us more?
By Lazypilot
#402165
Good points there re: the Fledge. I only have one Fledge flight, on the Lake Matthews training hill, long gone now.
I stood there and ground handled it in a mild breeze, feeling out the rudders, and repeating to myself over and over "I won't weight shift. I won't weight shift".
When it felt good I ran with it, got in the air, the right wing went down maybe as much as 10 degrees but it felt like 45 to me, I weight-shifted, got nothing from that and realized I had the rudder controls, the same ones I had just spent 20 minutes practicing with. With weight-shift not working I resigned myself to flying the glider correctly using the twist grips on the downtubes. I rocked and rolled to the LZ, when I slowed down she leveled and it was time for a flare so I grabbed both rudder wires and yanked. She nosed way up and dropped me on my feet with zero forward movement. Whew!

I've admired the Aolus since I first saw her at the Regionals, or was it the Nationals, at Crestline in I guess '83 or thereabouts. She was a step in the direction that I believe deserved to be followed, but alas she only became a piece of Hg history.
It's heartening that others feel the same way.
I have many various planforms floating around my head. One is similar to Aolus, but has a straight wing of moderate aspect ratio and a larger horizontal tail that has either dihedral or anhedral, depending on the CofG and a decalage adjustment available to the pilot in flight. My concept of it utilizes the tail not only as a stabilizer, but also as a power source for a camber and reflex modification, in flight of course. How that could work I don't know for sure, but it sounds like a neat idea so I'm stickin' to it.

The following is a flight of fancy, a daydream, a fantasy. But I believe that none of it is impossible. Difficult to manifest probably, but impossible, no way. You'll notice that there's no real description of what the glider looks like, please don't be disappointed by that. Instead see it as an invitation to dream up your version of a glider that flies the way I describe the character of this one, with your mind not polluted by a detailed illustration that I might come up with.

I see my position in this Brave New Glider project as being the role of a lightning rod, with a charge that attracts lightning from all of the creative minds hangin' around these parts. Let's hope it works, and eventually gets us the glider we all deserve to have.

I haven't a glider design finalized. I'm trying not to design from the outside looking in, rather I'd design from the inside out, trying to visualize the experience from where my head is positioned. As I look around, what do I see?

I'm standing on Crestline launch, in between two parallel longitudinal beams. I don't know if they are just aluminum tubes with some plate riveted on them that also have some parts bolted to them, or if they're made from a composite material. I'm able to hold these beams and control the glider's attitude with them. Not just man-handling here, the beams move relative to me and the rest of the glider, they serve as handles and flight controls at the same time, I communicate my desires of attitude adjustment through them. And once I'm seated comfortably they serve as armrests to.

I'm wearing a harness that encircles my waist with a wide padded strap and more straps under my crotch. There's shoulder straps and there are fittings on each hip. These fittings plug into brackets on the inside of the beams, they are part of an assembly closely resembling the "French Connection", which I believe was based on the hardware on each end of my Grandmothers porch "glider", basically a porch swing without the chains hanging it from the ceiling. The hardware allows easy swinging by the way it limits changes in the swing's height as it moves horizontally. This mechanism, when attached to the keel of a hang glider, allows the pilot to push out or pull in while rising an amount much less than if the harness were swinging on a strap fixed in one place on the keel. This reduces the "bar pressure" or more conventionally speaking, "stick forces".

This mechanism allows fore'n'aft movement of my body, and also converts that body motion into changes of the glider's aerodynamic shape. When I pull my body forward the glider's decalage is reduced and this allows keeping the nose down when I have a headwind. Moving myself aft increases decalage and the glider gets more nose light. I'm finding it very easy to control the pitch attitude, even when the gusts roll through.

The left side of the glider drops some, I pull upward on the left longitudinal beam. This action doesn't provide much rolling torque by itself, but it does cause the left wing to increase it's positive angle of incidence, by virtue of how the beams are connected to the wing, and the way they parallelogram relative to each other. I pull up on the left beam, and push the starboard beam down, which lowers the right wing wing's leading edge, reducing it's incidence. At the same time the tail is adjusted by my pulling the right beam back and pushing the left beam forward. This action has little torque around the yaw axis, but since it also bends camber into the rudder the glider remains pointed directly into the apparent wind, which at this time is angling in from the right, on average maybe as much as 15 degrees.

Some of my glider's weight is being supported by me, but the large diameter wheel behind me is carrying a lot of it. At the front of the longitudinal beams, about 7 or 8 feet ahead of me there's a lightweight nose wheel in it's deployed position a couple feet under the nose. This wheel is carrying some weight, I get a feel for how much weight by observing how much it's springy fork is curved. If I configure the glider for a nose down condition, the front elastic fork bends and the nose goes down, this increases the weight on the main wheel and it's suspension compresses as I and the glider settle and I take on a somewhat squatting posture. Once I have my vario and altimeter set I pull up on the beams, the glider's decalage increases and the headwind helps to lift the glider and I'm back to standing upright.

The glider is aligned with the slightly crossed wind, but both of my wheels are castoring, so I can launch directly down the ramp. I take a tentative step forward, the glider remains balanced so I decide it's time to tango.

The glider lifts as I allow the wings to move to the maximum incidence angle, I lift my feet and place them on a horizontal beam with non-skid tape on it. The glider is now rolling on it's wheels. As I push with my legs the front of the pilots seat, which has been hanging down behind my butt, is pulled forward and I easily slide up onto it's cushion. The seat is now my support, not the crotch straps. The seat is suspended now the same way my harness was, and I can move fore'n'aft about 16". I can't move downward or upwards or from side to side, but there's enough slack in the whole suspension that I don't feel restricted. I do have movement in yaw, much like I do in a car; I can easily turn to see where I've been.

After rolling down the ramp a ways I've got speed and I push back, the CofG moves aft a bit and at the same time decalage increases, the nose rises until my feet are about level with my butt and I'm stylin', cruising the famous Crestline ridge, headed for the house thermal about a hundred yards to the left.

When I get to where I think it's gonna be I push down the right beam and pull up on the left, The glider responds very quickly and I have to remind myself that I'm flying a real glider and not one that resists my efforts. I laugh and make a quick jerk on the beams, dumping some of the excess bank angle I got from putting too much muscle into her, and as the nose lifts I pull forward, dumping unneeded lift and keeping the glider's pitch attitude roughly level with the horizon.

Once in the thermal and settled down I keep turning to the right and climbing skyward. I reach for the handle that I pull to pull the wheels up out of the slipstream, not a lot of drag reduction but the glider is sensitive and I can feel my glide improve.

Up and up and then the inversion at 6500'. I head West and scoot on over to Pine Flats, I've heard that Pine was Bob Will's favorite site, but sad to say I never met him. The air is smooth so I bank left, relaxed this time and so not overbanking. I fly south and maintain height. I'm stoked and want to celebrate, so I pull on the beams and the glider noses down, and continues to nose down until I'm pointed down about 70 degrees. I ease off on my pull and the nose starts rising, as airspeed increases dramatically. With plenty of oomph stored up I push back, the G's build as the nose rises to about 45 degrees above the horizon and then I give a war whoop, pushing down on the right and pulling hard on the left, I feel the glider start to yaw to the left and I pivot to the right, I feel the rudder take hold and over we go, as I get to about 45 degrees past a vertical bank I pull my self forward, the reduced incidence keeps the nose from falling too much, but I'm moving right along and she rolls right on around. I stop the roll while banked right and push, the glider's wings grab the air and we're quickly turning back North. I think to myself, It's only been a few short years since I declared my independence from the weight-shift flying wing, and here I am, tearing it up in my sports car of a glider, ya know it's probably a sin to transport this thing on any car not made in Germany. It would simply be out of place.

I have a great flight, meeting up with friends working the afternoon thermals over the regionals launch, and just for fun I roll inverted and continue thermalling, right across from Dan and Shiloh the Wonderdog. The sink rate inverted isn't very good and so as they climb over me I roll upright, my glider never misses a beat and soon I'm gaining on them. A few more circles and I'm high enough to go to Marshal Peak. I cruise around, weaving through the Panties and working my way out front, slowly getting higher in the Glass-off. It's time to go land and tip a beer or three with my friends so I head out, stretching my legs out flat in front of me and laying back to where my head rests just in front of the "nose plate". I adjust wing incidence to get my body all lined up nice and neatly with the apparent wind, and in my minimum drag configuration I reduce camber and add a bit of reflex, going for a speed run to the LZ. I clear my airspace and pull off a few aero maneuvers, then settle down for my approach. I relax my legs and assume the more comfortable seating position, a posture not unlike the one I have in my car. I camber up to slow things down and deploy my special pulled down apex drogue, keeping the apex down and using only a small amount of 'chute. As I roll onto final with a glide angle to the spot of about 7:1 I let out some line, increasing 'chute area and killing some of my excess glide. As I descend into ground effect I let all the line out and settle down to where the main wheel makes contact. I hold the nose up but as more weight is picked up by the wheel the nose drops until the nose wheel hits. I'm now rolling along at 10 mph and come to a stop a little ways past the cone. Another satisfying flight, a flight in which I enjoyed 100% control of my gliders' attitude at all times, a long held dream finally coming true.

It wasn't easy, there were a lot of mistakes that had to be corrected, disappointment with having to shelve weeks and even months of work, and all that vehicle testing of the glider mounted inverted on the car, racing across the dry lakebed, sweating in the sun as I reworked a linkage that wasn't up to par. Going back to the shop and re-designing into the wee hours, sometimes wondering if the effort would ever pay off, but sticking to my belief that it really wasn't too much to ask for, a glider that could, and would, obey my every command without fighting back. It still takes longer to set up and break down than I'd like, and is bulkier by far than my old flex wing on top of the car. But I'll keep whittling away at it, and in the meantime she delivers a most satisfying day of ultralight soaring.

So that's my flight of fancy, a very entertaining day dream (for me anyway), a place in my consciousness where everything is possible and only the sky is the limit.

Flamers can flame, dreamers can dream, doers can do. It'll all work out as it's supposed to. Happy Trails ( a damn good Quicksilver album).
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By Harry
#402204
Goonie wrote: Wed Jan 31, 2018 4:35 am Bowsprit + deflexors?

Other than drag concerns, why did this design fall out of favor?
I owned the original single surface prototype. The wing was a dream to fly in ridge lift with fingertip control.
When the designer added the double surface, it became heavier and less nimble.

I also flew the larger production model. Setup and take down was a snap. Just pull one pin, the control bar slides forward and lays flat on the ground. You could leave it parked like that till you were ready to fly.

The downside was the landings. The tail prevented a good flare. The average pilot quickly learned that less than perfect timing on the flare resulted in very poor landings. Too many pilots crashed this wing on landing with little or no wind.

It was later learned that the leading edges needed to be reinforced with extra sleaving (adding yet more weight) as a friend of mine actually snapped the wing in half in a tight turn. I watched him spiral down with 2 attempts to deploy his chute before it opened. He landed safely after slicing through power lines and starting a fire. He walked away unharmed. Amazing luck.

The designer added washout tubes to put pilots at ease over the design. He said they were not needed because of the tail. And it's true. With the bar stuffed, you could never get the glider to dive fast enough, and I doubt anyone would have been able to loop this wing.

I never had problems landing my Fledge on postage stamps, but the Aolus needed a football field.

Hope that helps.
Safe flying to all
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By raquo
#402205
So... Does that mean the tail of Aelous was providing too much pitch stability? Preventing the pilot from pulling in and gaining airspeed? Sounds like it could have been set at a lower angle perhaps...
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By TjW
#402206
raquo wrote: Tue Feb 06, 2018 3:27 am So... Does that mean the tail of Aelous was providing too much pitch stability? Preventing the pilot from pulling in and gaining airspeed? Sounds like it could have been set at a lower angle perhaps...
Maybe. But there's been a definite change in pilot perception over how much pitch stability is "too much". In the late 70s and early 80s, tucking was still a concern. Not so much because of the offerings current at that time, but because pilots remembered gliders that would. A glider with the light pitch characteristics of my U2 would probably have been given the stinkeye, no matter how good the pitch curves from the test truck looked.
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By raquo
#402207
Thanks, that's something I didn't consider.

This new forum design needs to bring back upvoting...
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By red
#402209
raquo wrote: Tue Feb 06, 2018 11:50 amThanks, that's something I didn't consider.
This new forum design needs to bring back upvoting...
Campers,

Image

. . . :mrgreen:
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By raquo
#402215
Whoa, that Alien – curved tips in 1980? Looks so much like a Sport2 with a tail!

Looks like curved tips were too stiff and didn't work out well judging by what the delta82 comments say about this glider.
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By flyzguy
#402239
I have to side with Red and Lazy on this one. The restriction on control mechanisms has been terrible for the sport. A lot of great people are not with us because they could not make their glider turn when they needed to.

I want to bring up a new point: the growth of PGs. When you pull that string that wing turns. It doesn't consider your request - that freaking trailing edge plummets and that brake makes things happen - sometimes bad. Imagine if PG had a "weight shift only" tradition. So here we are with our roof racks and setup times and longer training learning curves and more difficult logistics, no hike-fly, etc... and on top of that we make our effort to save the sport worse by also self-enforcing that we can't also yank on a string/lever/knob to make our gliders easy to fly??? (Or the gliders that have this feature are 100 lbs and >$20,000 ). Plus we're a bunch of grumpy old men?

There is an argument to be made that none of our gliders have been pure weight shift since the introduction of the floating keel. We all pretty much already hang from the keel and yank on the sail (which floats relative to the keel) somewhat when we turn. Most of the wing flex is passive weight shift billow but some of that is direct mechanical leverage. I would say there's an argument to be said that "weight shift only" means "looks like weight shift at 1st glance". So screw the rules - we've all broken them already.

There's existence proof of folks who don't like weight shift: rigids. There are ideas that I think translate to simple, cheap flexwings that could dramatically improve things if we had the R&D time/money to evolve something simple: http://jmrware.com/articles/2008/leverl ... rLink.html

Now all that said, I have a new sport class glider coming my way soon so I'm not going to quit flying weight shift. I do get quizzical looks as to why I'm not buying a topless rocket from some of my peers who have succumbed to the idea that you must progress in glider as you progress in time/skill/experience. But while I enjoy flexwings I am honest about its limitations, don't see a lot of excuse for those limitations, and feel quite concerned about the impact it continues to have on my favorite sport.