US Hawks Hang Gliding Association

This topic is dedicated to the "The 5 ft-packed-HG Movement"
Move it forward! Some top designs are anticipated one day!. Ease of assembly and packing is invited. Safety is paramount.
Designs need not be fit for "all possible uses", but may be with limited activity. Consider "Dandy Handy Dockweiler" sledders in conservative airs. Yet consider more strenuous tasking also. Aim for bus-ability. Consider wearing toted sail. Consider having all tote parts play a part in the designs. Explore sail wrap after frame up; sail off first and then frame packing. Explore telescopic spars, tapered spars, angle cross-section. Consider fiberglass, carbon-fiber, titanium. Consider non-metal cables. Consider space frames. Consider whatever might bring to hang gliding a busable 5-ft long pack. Stay with airframes for coupling with pilot forces. Consider putting aside cars and trucks. Consider wheels or skid for drag or wheeled tote. Consider ribs that snap two parts on either side of the sail for no-pockets. Consider bags for the wing-wrap. Etc.

I think this is a very important topic for the future of hang gliding.

My Wills Wing Falcon III has a short pack option that lets me break it down to a relatively small length. But it takes a fair amount of work to do (I've only done it once so far). It also seems that some of the parts involved aren't designed to withstand repeated short packing on a regular basis without wearing out.

I think having an easy way to put the sail onto a mostly assembled frame would help a lot. That might involve some means (other than sewing) to fasten the sail to itself as it is wrapped around various poles and wires. That makes me think of things like zippers and velcro, but they have structural issues that would need to be resolved.

Very good topic Joe!!!

I am looking at a pack length of 2m which should still be bus-able (just) Anything smaller means more joins which add weight. Battens remain in the sails which concertina to the keel, so pack width is greater but it has all got to go somewhere. Wing L/E stiffening plastic sheet will be exoskeletal so it can be rolled up for packing but fitted like a nose cone (Velcro) and will provide a smooth surface for air flow. Weight should be around 20kg. Some cables need to be dis/connected but assembly time reasonably quick.

Just need the time to get around to building it.

Tony

Arp and BobK, the movement is on!
========================================
I am betting Pere Casellas will (or has) joined the movement.

http://dragonplate.com/ecart/categories.asp?cID=187

===========================================================================

Returning theme in my mind:
"sail may be separate from frame"
== Frame up. Then place the skin on the frame.
== Frame would be fully visible at each session assembly.
== Tote: Sail or skin might be worn on the body during tote on bus or train.

=================================================
Hang gliding is blessed with multiple niche activities that interest some pilots. One need not participate in all possible niche activities. Fun, healthy, and safe participation in one niche may be fully satisfactory. Exploring the pros and cons of possible niche activities may be enlightening, perhaps a preamble to new decision and commitment; and perhaps a new freedom of spirit. The 5-ft-packed-HG movement (perhaps up to 2 m; and some solutions might pack to 4 ft or 1 m or less; bring it on) is a niche activity in hang gliding world. One may play in this niche with various amounts of energy. Some persons will be with high focus. Potential effects on hang gliding from this niche activity may be very great.
=================================================

Another returning theme: solutions involving positive inflation of frame members. Specialized encased air beams?

=================================================

Search terms:
extensible beam
extendable beam
airbeam
air beam
tensegrity
spar
beam
space frame
antenna
coupling
shell
hybrid rib
Velcro
awning
tents
sails
ultralight structures
kite structures
collapsible beam
extend beam
telescopic beam
carbon fiber forms
nesting angles
bridge structures
truss
extendable truss
towers
lattice tower
truss tower
Inflato plane
ladders
pop ups
interior stays
interior web



===================

==========================================
Positive-inflation note:
Notice that one may tolerate certain leak rates in positively inflated air beams. For a niche HG purpose, say use of wing for 10 seconds only, then one might accept a leak rate that brings non-structural adequacy in 2 minutes. Then, just before launch, top off the positive inflation by way of muscle work; one might then be "good-to-go" for another 10 sec use. Consider having hook-in check be an avenue of pumping air into the wing for getting the wanted inflation pressures.
Consider grabbing wind ram air; capture and close; then top off positive pressure; fly for 7 seconds; flare; deflate; carry back. Repeat cycle.

============================

======
https://en.wikipedia.org/wiki/Lattice_tower

Do you remember the man that Richard Miller rented a back house from in San Marcos (or Escondido) for a time? I think his name was Fred Hagan, or something similar? He was working on an inflated main spar for a hang glider that would have a deep, high lift airfoil. I saw the poly-sheet proto-spar and it was about 15" in dia. His plan was to keep it inflated with a small on-board battery powered blower. As far as I know, he never got beyond prototypes of the spar. The prototype I saw was a straight tube but I assumed that it would be tapered toward the tips in an actual airframe design.

He was going for general purpose hang gliding but as you indicate, if only to be used at Dockweiler then that would give a lot more possibilities in design.

Frank

Frank,
Name sounds close. I did visit Richard Miller in that back house; he had scores of models of hang gliders and sailplanes he made. I don't recall the spar you mention.
However, inflated air beams have many possibilities. I explored my "cavexion" spars from 6 in diameter up to some beams of 3 ft. diameter; these were explored first for high jump landing cushion.

Air beams my have interior webs in various configurations. One of my favorite explorations is an encasement that holds two bladders that squeezes a span-wise coilable thin-plate of epoxy carbon fiber veener; the two bladders are positively inflated, but held to maximum size by the strength of the encasement; the encasement need not be non-porous. as it does not need to hold air, but only hold the two bladders. The squeezed web holds positive and negative flight forces in the vertical plane. The coilable web permits bus-ability; the bladders and encasement form busable totes. Using the anti-torsion of the air beam permits placement of airfoil ribs. The aim is to sack-skin the full span and use the air beam to hold back the compression of the tensioned sack skin. Sack skin could be zippered or corded laced at the center of the wing.

The grasp of the stationed ribs could permit graduated placement to give Culver Twist washout for flying wing solution. But exterior "high-hat" "tailing" is hoped for one solution for some pitch stability. First aim is Handy Dandy Dockweiler Positive-Inflated-Spar Busable package.

The ancient splinting of fluid beams (legs, arms, etc.) modernized in coined Tensairity (they don't own the principle which is in public domain, but they coined well a working business name) uses exterior compression member along with tension cables in skin of air beam:

Combining that with the above-mentioned web in air beam provides a direction for some super spars that may pack and tote to solve busable HG spars.

See also: https://en.wikipedia.org/wiki/Tensairity and its interior links.

Related to above post:

Name sounds close. I did visit Richard Miller in that back house; he had scores of models of hang gliders and sailplanes he made. I don't recall the spar you mention.

Joe,
Fred (if that was his name) had the "air spar" in the main house, so that's why you didn't see it at Richard's place. When he showed the test spar to me he used a vacuum cleaner blower output to inflate it.

Frank