[Frank Colver]

I think too little attention has been given to Chuck Hollinger's "Swingwing". Granted it would not have stood up to very many G's but I saw it soaring at Little Mountain and gliding down hills and I was always impressed. It was a very high camber flying rigid wing with tip drag rudders. It had much more camber than my Skysail and of course more reflex to stabilize that high camber airfoil. But it flew very slow and had a very low sink rate. When he was soaring Little Mountain there were no others in the air.

I agree that for a lot of hang gliding that we do a low sink is more important than a high L/D. L/D is necessary for long cross country flights but all the time i was flying I always wanted to land in a nearby LZ. Usually my truck was parked there with some cold ones in an ice chest for end of the day mental re-flying.

I don't have any very good photos of Chuck's glider but I'll attach one I have. Notice the small amount of sweep.

I often wonder what became of his hang glider when he died of a sudden heart attack several years ago. While he was still alive, and flying his very interesting electric R/C canard glider designs, he told me it was in the rafters of his garage in Costa Mesa. It may still be there. If it still exists it would be good for one of us to resurrect it if only for ideas on wing design.

BTW - He used foam core plastic sheet, scored on the inside, to cover the "D-tube" leading edge. The longitudinal scores were brushed with white glue after forming around the LE section. I remember being very impressed with the light weight of his wing.

Frank C.

Chuck Hollinger's Swingwing at Escpe Country 1974.jpg (193.8 KiB) Viewed 4778 times

[JoeF]

Nice bringing up Hollinger's Swinger

Hollinger1974Swinger.JPG (66.96 KiB) Viewed 4770 times

https://books.google.com/books?id=j989VTOlPwMC May 1974 Popular Science
Note: Swing-wing was Volmer Jensen's boomed-tail rigid HG.

[Dayhead]

While it is true that a flat glide angle is necessary for long distance flight, in practicality what is needed for casual flying is the ability to stay up in weak conditions. Also, human psychology is important: the ability to safely land just about anywhere gives the confidence required to go for it in the first place. This is what I think of when I talk about performance.

Hg has been trying to re-invent the sailplane for several decades. I believe we should back up and regroup, take a cold calculating look at just what it is we really want to do, and establish a goal based on what we learn from that exercise.

"High Performance" should not mean sacrificing good control to get a flat glide. In practical terms, you'll actually get more long flights with a very controllable glider that can circle tightly with minimal bank angle, all the while getting a low sink rate, than you will with a $20K 46' span ATOS. The successes I'm seeing in the PG world confirm this.

At my home site, PG's often make modest XC flights while the hangies stay in the fishbowl.

Some years ago a local instructor flew to Big Bear from Crestline, using a PG. While a HG could have made the flight, it would have been a dangerous stunt to attempt. But the ability to set down on a highway turnout, if need be, made this flight a PRACTICAL effort.

The design that I'm trying to figure out will have to have this ability. I'm seeing that a lot of wing area will be more important than high aspect ratio, and a relatively short span will allow for good low speed roll and directional control. The ability to control the glider precisely, especially at very low speeds, is an absolute necessity for safe and comfortable flight.

Many years ago I read an article in an airplane magazine about the high cost of high aspect ratio. I just wish I could remember the formula he used to describe the cost, in terms of both weight and money, of increasing the span.

Whatever it was, I know it made an impression on me, and it is influencing much of what I'm trying to say here.

[Frank Colver]

I always enjoyed the fact that my Wills SST was the original prototype built by Bob Wills, and not a production model. My enjoyment wasn't because of the prestige of the designer / builder (well maybe a little) it was because it had more sail area than the production SST's. Since I liked to fly and hopefully soar small hills and work small diameter thermals, the slower speed and lower sink rate were more important to me than glide ratio. It was also an advantage when landing on a "postage stamp" field, which I did many times. There was one low hill, near Riverside CA, where I had to approach over a grape vineyard and drop into a very small open spot. My larger area SST was very good for that.

As far as control went, it was sluggish in roll until I added the leading edge pulley system to transfer weight shift forces from one wing to the other. This was in the days before deep keel pockets and floating spars, which now accomplish the same thing in newer flex wings.

The attached photo was taken before the pulley system was installed. The LE wires that can be seen are for stiffening the leading edge tubes, similar to a sail boat mast, and came on this glider.

Frank Colver

My first SST flights at Little Norco hill (a little higher than Dockweiler).

1st time flying SST @ Norco.jpg (175.72 KiB) Viewed 4758 times

[magentabluesky]

I flew a 1978 Wills Wing Alpha 210 when I weighed in at 145 pounds with the pulley system connecting the wing tips. The pulley system worked great.

I believe the current glider’s controllability could be enhanced with a pulley system enter connecting the fiber glass wand wing tips or the tips connected to the floating cross bar with a series of pulleys multiplying the movement of the crossbar effecting the tips.

Large square footage gliders are fun to fly in light conditions and soarable when the smaller gliders will result in an early landing. Having flown Wills Wing Falcons in the sizes 170, 195, and 220, the later two, 195 and 220 seem to have very stiff outer leading edges. Of course the manufacturer is designing the larger gliders to carry more weight without structural failure but at the expense of handling by lighter pilots. Compared to aluminum and carbon fiber, fiberglass offers greater elasticity but still has ultimate load capability on par with aluminum and carbon fiber. I think the use of fiberglass outer leading edges would benefit controllability of the larger hang gliders.

Joe should have some expertise in fiber glass poles as a pole vaulter.

[JoeF]

Photo is not self, but some UK athlete, I guess.

Mike, in high school I did some official pole vaulting. A tapered Swedish steel pole once broke on me and I came within an inch of breaking my neck in the micro hang gliding that occurred following the break. The later fiberglass poles were manufactured to match the preference of the weighted pole vaulter as to stiffness and pole weight. However, 98% of my track-and-field activity from 7th grade until even now has been in the running high jump, a special form of micro hang gliding that has hair as the parasol wing in the flight system; I flew my micro hang glider self over 3 ft 7 in in the seventh grade spring; flight progress continued to set a world-age-record at the time in 1958 at age 15 of flying over a barrier at 6 ft 8.25 in on the field of Occidental College where later I would attend in college. In college I micro hang glided via the type called running high jump over a barrier of 7 ft 0 in at the Stanford University field to earn a spot on the 1960 USA T&F Olympic Team for the Rome Olympics. In 1962 my highest RHJ MHG (running high jump micro hang glide) was flown in the spring; the barrier stayed up for about 6 seconds; the bar was at 7 ft 4.75 in at the moment when the world official world record for that type of hang glider flight was 7 ft 4.50 in by Brumel of Russia. Later I would add other wings to my hang gliding tool chest and end up flying over barriers that were much taller than those T&F high jump bars. I was the "baby" on the men's USA Rome Olympics squad at age 17. Now at age 73, I am still jumping with hair wings and also with other hang glider wings; today I am a U. S. Hawk.
https://en.wikipedia.org/wiki/Joe_Faust#Track_.26_Field_Athletics:_Running_High_Jumper

Study: http://illumin.usc.edu/143/soaring-to-new-heights-the-evolution-of-pole-vaulting-and-pole-materials/ Soaring to New Heights: The Evolution of Pole Vaulting and Pole Materials


Hybrid pole vault pole mixes carbon fiber with S-glass ... and careful manufacturing process: Skypole Carbon
https://www.gillathletics.com/product/skypole-carbon-vaulting-pole

[Rick Masters]

...what it is we really want to do...

What do you mean, "we," paleface?
I flew Torrey once in a great big slow hang glider but got so bored I landed after one pass and drove back to Owens Valley and my high l/d wing.
So booooooooooring...
Big slow, easy-handling hang gliders have been around forever.
They're great to learn on but they are really dangerous if you're flying mountains or XC and the wind picks up.
Kinda like paragliders...
(BTW, cities aren't the best choice for cross country.)

[Frank Colver]

To each his own, Rick. A far more boring thing would be if we were all alike and we all enjoyed the exact same things.

Frank

[Dayhead]

The glider design I'm philosophizing about will have a wider speed range than the big 'Rogallo' designs we all knew.

As I mentioned previously, it has the working title of Gap Filler. It will fit neatly in the gap between HG and PG.

I regularly fly a large SS glider, a 187 Harrier. I weigh only 150 so my wing loading is fairly low, but the glider is still too fast to really enjoy mixing it up with my PG friends.

I have only vague creative visualisation images of this design. By discussing it with others I will get a clearer picture.

But so far it has an almost straight wing, a single I beam type spar, and ribs that fold along the spar. The wing will be 100% double surfaced. It will have a tail fin or fins. It will be built in as lightweight as possible, no more than 50 lbs. By current standards it's wingspan will be relatively short and it will have a large chord. The low aspect ratio is not itself a design goal, it is something that simply results from my wanting gobs of wing area and a short span. I believe that a short span will allow for a lighter weight structure and also allow for fast and precise roll control. It is my goal to make the design as clean as I can, so as to minimize the adverse effects of low A/R.

I have a cute little 135 Sensor to use for that type of flying, and of course "Autumn" the big Harrier as well.

I just want to be able to catch that last launch shuttle of the day and go hang around Marshal with my PG friends, but without having to resort to using a PG myself.

I believe that by using an efficient structural design I can achieve the goal of matching PG minimum speeds. Aluminum tubing is great for a production glider, but I think I can reduce weight per square foot considerably by having a relatively thick airfoil which will allow for a tall full-depth wing spar, which will be made as light as possible, built up using composite techniques. The ribs will be built in a manner similar to the spar and will remain in the wing for de-rigging. I'm investigating the concept of a spar designed to bend and/or twist in a controlled fashion, so that the wing can "vent" off excess lift in the outboard area. If that can make a significant contribution to lightness I'll use it. I see no need for a glider that can pull high G loads.

My goal is to be completely set-up and launch ready in as little as 5 minutes. Aerodynamic controls, or a hybrid of weight shift and mechanical control will allow for fun and relaxed soaring in a crowd.

While there aren't very many of us in this small niche 'sport', there's a broad range of attitude and individualism within it. "To each his own" as the saying goes. I believe it to be a mistake to think that my own individualism and attitude is the only right one to have. I've never met Rick Masters, but I do hope to sit down with him someday, put away some brewskis and hear some great history from him. We're more alike than different, I'm sure, and since preaching to the choir is boring and non-productive, I hope for some heated discussion. Hopefully no one will have to call the law on us.

[Rick Masters]

To accommodate parachutes within the USHGA, the national organization chose to ignore some important and hard-won standards - particularly positive reflex and the negative G loading minimum requirement hammered out over much intelligent discussion by the Hang Gliding Manufacturers Association in the second half of the 1970s. These protocols resulted in mandatory design testing and USHGA-recognized type certification for hang gliders, which I regard as the USHGA's finest hour.
http://www.hgma.net/about_detailed_faq.asp

I see no need for a glider that can pull high G loads.

I do. Any hang glider can enter an aggravated stall or encounter severe turbulence. Wishful thinking is okay on the ground but all hang gliders need to be able to pull high G loads to survive recovery in these situations.