[wingspan33]

Well, Rick, you may indeed be right.

I've thought of many versions of alternative weight shift methods. One included having water ballast transferred, within the cross tube, to a position outboard of the keel.

A pretty simple system is possible using a a reserve "bladder" just above the pilot. Which, when the pilot shifts to either side, causes the bladder to be compressed sending the liquid to the appropriate side cross tube reservoir. A lot of water wouldn't have to move, or move very far, to equal a typical shift in weight of (let's say) 2 feet from center by an average pilot.

Such a system could also be easily quantified by simply suspending a glider from it's CG and checking the comparable downward force at the wing tip, in each system.

Also, with my idea of the pilot's suspension becoming shorter once they rotate to prone position (let's say, via a foot stirrup within the harness), traditional weight shift could be easily resumed by the pilot simply releasing the stirrup - and therefore lengthening the suspension "strap".

It's great fun thinking about the possible future of hang gliding design! I hope we're all healthy enough to be flying a "new" hang glider 20 years from now!

[wingspan33]

One of the most obvious unique qualities of a modern hang glider is the "flex" built into both the frame and the wing/sail.

The first hang glider I owned, an Eipper-Formance Flexi Flier 17' Standard, clearly had weight shift control. But there was no roach in the sail and the two sides of the sail always had the same degree of "billow". Well, that is, unless something really bad was going on.

But hang gliders evolved pretty quickly to include roach in the sail and intentionally flexible air frames. The next step was keel pockets, then the "floating" cross tube. Both of these features aided in the "billow" (AKA twist) of the sail changing, in an asymmetrical fashion, in the process of weight shift. This asymmetrical change in sail shape amplified the effect of weight shift by itself.

When you think about it, the total aircraft known as a hang glider is almost alive. The sail, in harmony with the flexible air frame, changes shape in response to the pilot's control inputs. Besides an actual bird's wing, what other aircraft can claim such qualities?

Please post an answer if you know of one.

[reluctantsparrow]

It is so refreshing to find people who are actually using their own mind. I have not thought about the negative G predicament we face, I have not devoted on Nueron to thinking about it. Shame on me.
Okay...thinking...thinking.....re-reading presentation of problem and possible solutions....Kiss method?.....Okay...got an idea...
How about....since the loss of positive Gs and the hang strap going loose is the first thing that happens......the hang loop should be the trigger for whatever device is used i think.
whatever...trigger...is built into our hang loop system would be activated by a line running down to the pilots shoulder strap where a pin is pulled to activate a trigger in the hang loop area that is designed to ...trigger.....the instant the hang loops go negative.
Now that the...trigger is built into the hang loop area with an activation line running down the harness mainlines I am going to try to find a solution using only the harness itself to keep it as simple and compact as possible.

Okay....there is another line that runs out from the hips area of my harness from a ratcheting reel inside my harness....After I take off I pull this line out further and run it under my basetube, then back up to secure connection loop near the shoulder straps......then I pull enough slack in the lower line (via the spring loaded ratchet device inside the harness) to let the line droop a few inches, maybe even a foot below my base tube so as not to interfere with regular control movements in positive G.

So........when the straps go loose...the trigger activates the Ratchet thingy inside the harness to suck up the droopy lower line so the harness can not fall away from the basetube since there is a strong, taught line now keeping the harness from doing so.....
If it ran from your waist to your shoulders a pilot would still have some degree of control over pitch. The Pilot should still retaing the ability to slide foreward and backward (pitch control) without falling into the glider hanging from this line routed under the basetube (OVER the basetube once your inverted)

Once the pilot has regained right side up the lock on the ratchet is dis-engaged so the pilot can again pull slack into the line for regular flight.....
The trigger should be made in a way that it also re-ingages when positive G is once again attained.
This could be as simple as a spring loaded pin down on the ratchet device. Positive G pulls the pin one way (against its own spring), while negative G allows the spring to pull the pin the other way....RS

[reluctantsparrow]

The reasoning for the lower line Attaching somewhere near the pilots waist:
i realize that does not distribute a pilots negative weight evenly but if the pilot has lost his/her grip on the control bar it limits the distance the pilot can fall away from the control bar forward or at.
The piot will not have fallen so far away that he/she can not reach backward or foreward to regain a grip on the control bar and attempt to regain control if the wing is still structurally sound, which it should still be in most upside down scenarios if the pilots body has not been allowed to fall into the glider and cause breakage due to the line previously descrbed.

[Bill Cummings]

The reasoning for the lower line Attaching somewhere near the pilots waist:
i realize that does not distribute a pilots negative weight evenly but if the pilot has lost his/her grip on the control bar it limits the distance the pilot can fall away from the control bar forward or at.
The piot will not have fallen so far away that he/she can not reach backward or foreward to regain a grip on the control bar and attempt to regain control if the wing is still structurally sound, which it should still be in most upside down scenarios if the pilots body has not been allowed to fall into the glider and cause breakage due to the line previously descrbed.

So what's missing? Maybe also provide an answer in case of a water landing and put a cable inside the basetube.

[reluctantsparrow]

Woke up this morning thinking about the other two ideas as well.
i like the carbon tube around the main lines idea with some modifications.
make it a solid carbon tube with one slip joint capable of moving one inch in a negative G situation.
The solid carbon tube is attached to the gliders keel directly the same as a trike wing is currantly attached (a swiveling block attchment)
This would only work with harnesses with a backframe of some sort I think and there is still the problem of losing a grip on the control bar....so....
with that one inch slip joint as the zero G ....trigger.... that would activate my ratcheting reel inside the harness with a line routed under the basetube the pilot could not fall away from the basetube and would be held inverted in the same position relative to the control bar minus one inch (the trigger)
This would work on harnesses with solid backframes but I dont see any reason the ratcheting reel would not work with any harness, soft or hard.
I woke up realizing the activation pin is not neccesary.
a spring loaded pin with a line running directly up the mains to the hang loops and down to the ratcheting device inside the harness would automatically activate the device when a zero G load is experienced. All the slack line is instantly reeled in and the pilot can not fall towards the keel.
The hip and shoulder attachment points would keep the pilot within control bar reach.
And yes, a cable running through the basetube along with a stronger basetube capable of supporting the pilots full weight without deformation......yep....should work just fine.
a reachable button to disengage the locked up device and pull slack back into the line when the positive position in regained.
flying around with slack in the line would not be any more difficult than flying around with a slack Aero tow bridle.
Enough slack for the pilot to fully push out and pull in of course, that is instantly reeled in and made taught in a negative G situation........hope someone makes one....My mind is preoccupied with some other ideas at this time.

[Bill Cummings]

On my other laptop I have a drawing of an idea that I came up with that would attach to a sprog cable that would twist the cable shortening it to raise the sprog. This would be accomplished with height shift to raise the sprog thus raising the trailing edge to help with a turn. To offset any yaw a vertical stabilizer would also be used.

The sprog cable would have an Aluminum 3/16" Diam. by 18" long round stock rod attached along side of the sprog cable by means of two copper electrical split bolts.

One split bolt would attach to the sprog cable at midway on the rod. The other split bolt would attach the end of the rod to the sprog cable.

At the free end of the rod a control cord would be fastened.

Pulling on the cord would make the center rod split bolt pull while the other split bolt at the end of the rod would push toward the wing tip.

The force would move the sprog cable out of a straight position and raise the sprog tube.

The raised sprog tube would raise the transverse batten raising the two battens above the transverse batten.

This would cause the wing tip to drop which is what the weight shifted pilot was also doing. Trying to drop that wingtip.

One of the most obvious unique qualities of a modern hang glider is the "flex" built into both the frame and the wing/sail.

The first hang glider I owned, an Eipper-Formance Flexi Flier 17' Standard, clearly had weight shift control. But there was no roach in the sail and the two sides of the sail always had the same degree of "billow". Well, that is, unless something really bad was going on.

But hang gliders evolved pretty quickly to include roach in the sail and intentionally flexible air frames. The next step was keel pockets, then the "floating" cross tube. Both of these features aided in the "billow" (AKA twist) of the sail changing, in an asymmetrical fashion, in the process of weight shift. This asymmetrical change in sail shape amplified the effect of weight shift by itself.

When you think about it, the total aircraft known as a hang glider is almost alive. The sail, in harmony with the flexible air frame, changes shape in response to the pilot's control inputs. Besides an actual bird's wing, what other aircraft can claim such qualities?

Please post an answer if you know of one.

[KaiMartin]

When you think about it, the total aircraft known as a hang glider is almost alive. The sail, in harmony with the flexible air frame, changes shape in response to the pilot's control inputs. Besides an actual bird's wing, what other aircraft can claim such qualities?

Watch the wing of an airliner transform while on landing approach. Flaps and slats increase the camber, stabilize the boundary layer, and increase the effective wing area by quite a bit.

Paraglider pilots morph their wings quite a bit, too. It is not just pulling brakes, but also weight shift. Occasionally, they pull the B-lines to induce a stall, or fold the wing tips.

---<)kaimartin(>---

[wingspan33]

When you think about it, the total aircraft known as a hang glider is almost alive. The sail, in harmony with the flexible air frame, changes shape in response to the pilot's control inputs. Besides an actual bird's wing, what other aircraft can claim such qualities?

Watch the wing of an airliner transform while on landing approach. Flaps and slats increase the camber, stabilize the boundary layer, and increase the effective wing area by quite a bit.

Paraglider pilots morph their wings quite a bit, too. It is not just pulling brakes, but also weight shift. Occasionally, they pull the B-lines to induce a stall, or fold the wing tips.

---<)kaimartin(>---

Kai,

You are right in connection with how a large commercial jet changes it's aerodynamic qualities at various points during it's flight. However, it isn't in direct response to input from a physical body (emph. on direct). It's always(?) a "fly by wire" system. And unlike a bird's wing, a jet's control surfaces are, for all intents and purposes, utterly foreign.

Also consider, no bird's wing can fly at multiples of 100 mph. No fully extended bird's wing can even fly at the typical landing speed of a commercial jet. One exception possibly being a peregrine falcon in a full on stoop - 242 mph!. But even there, is the peregrine actually flying or in semi-aerodynamic free fall - kind of like a person wearing a wing suit?

A commercial jet's wing can't realistically be considered similar to a natural flying creatures wing. Lots of aerodynamic variability possible for sure, but by quite different means.

As to collapsible canopies, I believe that a better word than "morph" would be deform and/or distort. No natural flying creature has a weight (either its own body or some other living mass) hanging by numerous "bio-fibers" some significant distance below its wing. Such bio-fibers being manipulated to distort/deform its wing - to affect aerodynamic control. The way a bird can manipulate its feathers is closer to some of the aerodynamic controls on a jet, as compared to the way a collapsible canopy is distorted/controlled. Also, the simple form of a collapsible canopy involves a thin, air filled membrane taking (much of the time) an aerodynamic shape. No natural air born creature takes such a form.

My above comments could also be placed in the context of imaging a living creature in the form of a hang glider, or a commercial jet, or a collapsible canopy. Which picture comes closest to resembling a living winged creature - even forgetting how they may be controlled?

I do appreciate your contribution. I think it's helped define how unique a hang glider actually is!

[wingspan33]

Real interesting idea Bill!

Describing mechanical devices can be hard to follow, but I think I have a pretty good picture of your concept. I would simplify it (I think?) by making the sprog cable two joined cables (at the mid point) and having the "control cable/line" connect there. A simple pull on that cable/line would effectively shorten the distance from the LE connection point to that on the sprog. Also, considering identical control lines going to both left and right wingtips, tightening one side would simultaneously loosen the other. The set up could be "tuned" so that the looser side would place the sprog lower than compared to how it would be positioned in a "symmetrical" (pilot centered) position.

I think both ideas are very similar (mainly because you helped me think of my version), but I'd love to see the renderings of your design.

I think I need to start a new thread topic on Possible Future Hang Glider Design Ideas! Kind of like an online HG design Think Tank!

On my other laptop I have a drawing of an idea that I came up with that would attach to a sprog cable that would twist the cable shortening it to raise the sprog. This would be accomplished with height shift to raise the sprog thus raising the trailing edge to help with a turn. To offset any yaw a vertical stabilizer would also be used.

The sprog cable would have an Aluminum 3/16" Diam. by 18" long round stock rod attached along side of the sprog cable by means of two copper electrical split bolts.

One split bolt would attach to the sprog cable at midway on the rod. The other split bolt would attach the end of the rod to the sprog cable. . . .