[Dayhead]

This is a subject that I have been meditating on for quite some time now.

I hear and read about the alleged decline in participation in HG, and how PG is thriving.

Any un-biased observer should be able to see why wanna-be pilots find PG more attractive than HG. Standing around in the Andy Jackson Memorial International Airpark at a busy fly-in shows that a PG landing is a total non-event, while everyone stands up to watch HG's, piloted by "experts", come in to land. A good landing by a HG is greeted by cheers, an acknowledgement that landing one successfully is a demonstration not just of skill, but good luck as well.

A "blown launch" in a PG rarely results in anything more than getting dirty and having to untangle a bunch of string from bushes. With a HG, there is a lot of risk for injury and expensive damage to equipment.

There are many who support the status quo. They like to point out that all you have to do is be careful. And practice a lot. The list is long and and I'm simply not willing to go any further into it.

This post is only the opinion of one pilot, and yet it is the opinion of a pilot aged 63 with 39 years in HG, and so I believe has some validity. But that's your choice to agree or not.

My opinion, simply stated, is that we really oughta "back up and regroup".

By that I mean take a good long critical look at our technology, calmly analyze it, and see if we can't find a place in our history where taking a different path might have made a difference in the situation we find ourselves in today. If we can do that, we can consider ways to improve the technology in such a manner as to possibly slow if not reverse the decline, if it exists. I believe it does.

I'm neither Psychologist or Engineer, but I am "mechanically inclined", and like many my age I've become familiar with the "Human Condition". So I believe I can make some statements that have some credibility.

Possibly the best place to start is with the List of Priorities that we use to design a foot-launchable flying apparatus. This would apply to both disciplines now enjoyed, or endured, as you see fit to state it. Likely a bit of both will be the consensus.

There appears to be a lot of effort directed towards creating an open-air foot launchable sailplane. It can be argued that expanding the performance envelope in that direction has succeeded in contracting other envelopes.

Some of you will recall the preface to The Last Whole Earth Catalog, by Stewart Brand. A partial quote: "....has succeeded to the point where the gross defects obscure the actual gains....". I contend that Hg design evolution is a prime example of this. Our existing Priorities List is in need of a re-evaluation.

So how should we re-arrange the priorities list? Well, here's where we need to study the paraglider. How do PG's differ from HG's? First off we notice how extremely lightweight and compact they are in comparison. And then let's look at the performance envelope, where we can readily see that the "high-speed flat-glide angle" just barely exists, and in comparison to high-performance HG's it doesn't even exist at all. And yet the PG's are kicking butt, especially in the aerobatics department, and at many flying sites are doing quite well in the XC arena. Perhaps we can apply "Freakonomics" here. Could it be that the ability to pull off a safe landing almost anywhere actually trumps high-speed flat-glide angle?

Well, yes and no. I think the current open-distance record for HG stands at 475 miles, while for PG it's less than half of that. But these record setting pilots represent only a very small percentage of the pilot population as a whole. I know that most of the flyers in my club rarely venture more than a couple dozen miles from the fishbowl, and depending on your definition of that fishbowl, many never even leave it at all. And the most popular XC destination, a local airport, features a landing spot in the shade of a micro-brewery. Go figure...

Gotta go see the chiropractor. Most of my HG's weigh close to 70 lbs. I wonder if the PG crowd needs bone-crushing on a regular basis.... Anyway, I'm far from finished with this post/rant/ philosophizing.....

[Dayhead]

Back from the Doc. Much better now!

So as I was sayin', most pilots aren't trying to fly as far as they can as fast as they can. Most of us just want to get up and fly around for awhile, enjoy the view, and experience the excitement of a few thermal climbs. Many would find happiness in PG but don't trust them, so stick with HG instead.

I believe we need a new design of foot-launchable flying apparatus.
The key to doing that lies in keeping an open mind, and the willingness to focus on a defined design goal. That goal will be defined by the order of priorities.

[Rick Masters]

I believe we need a new design of foot-launchable flying apparatus.

I would argue we have everything we need, already.
If you want to go fast and far, and have the skill to land out, you're looking at 70 to 100 pounds at take-off.
If you want to learn or boat around at the local bowl, a little more than half that.
If you want a hang glider to weigh what a paraglider does, it'll never happen.
Beta was vastly superior to VHS but VHS won.
More money went into the promotion of VHS and most people weren't critical enough to see the difference.
Beta was more expensive and the retail salesmen were always pushing the cheaper VHS units with a better margin.
After a while, you couldn't even find consumer Beta.
But on the Pro side, Beta went digital, then led to HDD and chip storage and VHS vanished almost overnight, replaced by DVDs.
To me, hang gliding is a lot like Beta.
We're in a down cycle brought on by not having a national hang gliding organization.
We're trying to promote hang gliding from within a paragliding organization.
It's ridiculous. We need to work on changing that first.

[Bob Kuczewski]

My 2 cents ... I personally feel that a quick short packable hang glider would make a huge difference in saving the sport.

Many of the young people who would be most likely to take up hang gliding live in dorms, barracks, apartments, or condos. They also drive tiny cars, motorcycles, scooters, bicycles, or skateboards.

It takes a fair amount of "additional" investment to be able to transport and store a full-sized hang glider. The younger generation might look wistfully at the hang glider's performance, but the practicality of a bag on their back will win the day.

As far as performance, there are certainly those who thrive on get high and go far. But I suspect the vast majority of HG pilots didn't get into the sport for that specific purpose. In fact, I suspect it's just the opposite - most people come to hang gliding just to fly, and those who get into competition do so because they end up looking for even more than flying. But even those folks went through the "wow, I can't believe I'm flying" phase before they set their sights on things that they didn't even know were possible when they started.

I think Joe Faust's quest for "busable" hang gliders is on the right track. I don't think the weight is so critical - especially to young men - but the length is a deal breaker for just too many people.

Good topic Steve!!!     

[Frank Colver]

On your "reasons for flying": during my hang gliding years (the're starting up again) I often told other HG pilots that i would never do any significant cross country flights because I was unwilling to fly in the atmospheric conditions that make such flights possible. I was always happy with flying local mountain sites, in mild conditions, and using the local LZ. I was able to utilize my share of gentle thermals (well, OK, some turned out to be not so gentle) to extend flight times and then land where the vehicles (and coolers of beer) were.

I always admired the cross country flying HG pilots, but I did not wish to join them in those conditions. I did gladly provide variometers to make their task easier.

Frank Colver

[KaiMartin]

Some of you will recall the preface to The Last Whole Earth Catalog, by Stewart Brand. A partial quote: "....has succeeded to the point where the gross defects obscure the actual gains....". I contend that Hg design evolution is a prime example of this. Our existing Priorities List is in need of a re-evaluation.

So how should we re-arrange the priorities list? Well, here's where we need to study the paraglider. How do PG's differ from HG's? First off we notice how extremely lightweight and compact they are in comparison. And then let's look at the performance envelope, where we can readily see that the "high-speed flat-glide angle" just barely exists, and in comparison to high-performance HG's it doesn't even exist at all. And yet the PG's are kicking butt, especially in the aerobatics department, and at many flying sites are doing quite well in the XC arena. Perhaps we can apply "Freakonomics" here. Could it be that the ability to pull off a safe landing almost anywhere actually trumps high-speed flat-glide angle?

I am in violent agreement with all the points you raise. This includes the main sentiment that hang gliding sort of went too far in a particular direction. A radical re-evaluation of goals might be necessary to foster the sport. I also agree with mark and probably JoeF that size for transport and storage is the most pressing issue with current gliders.

In addition, I note that hang gliding itself is a product of such a re-evaluation. From a technology point of view, all necessary components would have been readily available decades before. As can be seen with the famous pioneering "bamboo gliders" even the quickly adapted materials aluminium tubes for the frame and dacron for the sail were not really a requirement. But people who dreamt the dream motor-less personal flight needed to collectively shift away from the mindset that lead to sail planes.

As you might have guessed from my other posts, I think, currently dominating constructions leave no much room for improvements by tweaking parameters. After all, they have evolved incrementally over the years and were designed by people who know what they do. If it were possible to fit a current flex with joints or similar and make it fit into Joe's 5ft package without severely compromising other aspects of the wing, it probably would already have been done. If anything is going to shift main stream attention away from para gliders back to hang gliding, it will probably be a radically different design. Not because of the "design" but because of its desirable properties.

The "desirable properties" would have to be a mix of the whole package → glide angle, fun in the air, handling on the ground, security, ease of use, price, you name it. Complete failure in one department and the design has no chance to get adopted by more than a hand full of enthusiasts. An argument to support this notion: Paragliders have been around for about as long as hang gliders. But they have been largely ignored until about 1990 (or 1985?) when their glide angle was finally comparable with early hang gliders.

---<)kaimartin(>---

[Frank Colver]

I will weigh-in on only one of the disadvantages of HG's that Dayhead listed and that is the more difficult landing of the hang glider. If hang gliders had a highly effective landing flap system they could equal the PG landing ease and speed. I'm speaking of high flap angles like 75 to 90 degrees. I think we tend to think of the "steep angle flare" of a hang glider as being the same as using flaps but it is not. Flaps decrease the lift to drag ratio while maintaining full control. They also have short distance landing advantages over spoilers. Spoilers reduce lift significantly while not increasing drag to the point of slowing the glider much, so landings are still fast. Flaps actually increase lift but make a dramatic increase in drag and slow the glide. The angle of attack of the wing is lowered when flaps are applied so that the stall (drag) remains at the flap and doesn't progress along the main portion of the wing surface.

Paragliders have flaps - in fact that is all they have - 2 Independent flaps that are called brakes in PG speak. It is their only method of control which is a disadvantage in certain situations but it does make for slow landing speeds if used correctly.

I come to this out of decades of flying R/C model gliders and having to land in tight spaces. For a long time I depended on spoilers to get down in a short distance but the still high speed would often send me beyond the landing area. Sailplanes most often are using runways of sufficient length with off- field landings being the exception. My awakening to the advantage of large steep angle flaps was a difficult short length ridge soaring hill top landing area for the slope soaring R/C gliders. The landing area also had a down sloping surface and the approach was over a barbed wire fence. With spoilers up I would just clear the fence and then the model would bounce and slide right over the edge. Another flier with flaps on his model would make the same approach and drop slowly and comfortably a short distance inside the fence. Also flaps allow altitude to be burned off with down elevator without storing a lot more energy. I used this just yesterday when my neck was getting sore from flying (from my desert driveway LZ) a 5 1/2 foot span R/C glider in thermal lift that was so prevalent that I couldn't find enough sink to get the glider down. With 80* flaps down I put it into a steep dive and it barely gained any recovery altitude when I ended the dive with flaps still deployed. I had burned off several hundred feet (also scared the heck out of the hawk that had been circling with my glider)

In conclusion: I have no idea how some big and effective landing flaps could be added to hang glider designs but I think it is a worthwhile goal for some serious and heavy brain work. We would then have the paraglider "brakes" with the added advantage of other available pilot control inputs like forward weight shift to keep the wing flying, not stalled as is the case with the PG.

Frank Colver

BTW - Watching my R/C glider settle slowly into a small area surrounded by model eating cactus, brush, and thorny ocotillos is a sight to behold. Even when I misjudge and it lands into one of these model airplane hungry goblins, there is very little damage because it is going so slow.

[Rick Masters]

I started using drouge chutes in 1979.
They work well. In my opinion, they are an integral part of the high performance hang glider package, particularly for calm and/or high altitude density landings.
Just because others are too lazy to use them doesn't mean there is something wrong with the hang glider.

[KaiMartin]

I will weigh-in on only one of the disadvantages of HG's that Dayhead listed and that is the more difficult landing of the hang glider. If hang gliders had a highly effective landing flap system they could equal the PG landing ease and speed. I'm speaking of high flap angles like 75 to 90 degrees.

This happens to be my entry point to theory gliding and wishful construction
I too feel that the difficulty to pull off a proper landing is a major weak spot of current mainstream constructions.

Turns out, there are reasons why we don't see large flaps since ages. The most obvious reason is mechanical. The way flaps operate on conventional air planes requires a stiff wing. On a hang glider a conventional flap would deform the sail in ways which counteract the desired effect. But this can be solved mechanical solutions that are adapted to a flexible sail. E.g. the flap mechanic might be integrated with regular battens.

But there also is a more fundamental reason: Flaps effectively make the wing behave as if the airfoil increased its camber. The desired consequence is an increased coefficient of lift (Cl). Unfortunately, more camber also increases the coefficient of the pitching moment (Cm). This messes with pitch stability. If the flaps are placed at the centre of the wing, an increased Cm tends to make the wing pitch unstable. Any positive Cm from the middle of the wing must be countered by twist at the outer wings. To keep the efficiency of the wing acceptable, the twist is kept as low as acceptable. So there is not much margin for the flaps to mess with.
Large flaps on the outer wings are even worse. Over there, a significant increase of lift already renders the wing unstable.

Traditional planes don't suffer from this kind of problem because their tail planes provide massive amounts of dynamic pitch stability. And para gliders get dynamic pitch stability from the pendulum effect.

---<)kaimartin(>---

[Rick Masters]

With the exception of free-flying (fowler or Junkers flaps), flying wings do not do well with flaps.





Unfortunately, free-flying flaps add the drag of another pair of surfaces and have not yet proven suitable for flexwings. Some high-performance rigid wings have experienced control reversal with aggressive pop-up spoilers at flare. Well-designed mild spoileons seem to help reduce landing speed on both flex and rigid wings without much drag penalty during high speed flight.
http://www.aeroexperiments.org/spoileronsflex.shtml