Sat Dec 24, 2011 10:51 am
Whack No-More Safe Splat
... an open design project. Chime in with photographs, drawings, ideas,
experiences, calculations, prototypes, weighings, pros, cons, what ifs,
etc.
Easy conventional solution: Just fly in a manner that gives a great
landing without a whack; such is a separate topic and an important topic.
But this present topic invites some other scenarios, and some deliberate
specialized activities besides the emergency mishap handling. Meet the
ground or water with a happy face without damages or with less damages.
Avoid broken necks, lost knee caps, broken fingers, broken arms, etc..
How? Notice how wheels can gouge soil and act like a brake and pitch
rotating cause; notice the same for basebar parts and knuckles. Look at
the history of aviation and various ways designers responded to the
landing event. Look at the history of hang gliding and see some partial
solutions to the whack event. May this thread bring together these history
of solutions, partial solutions, etc. A target is a set of solutions that
may be explored. Ski, skids, rollers. arrestors, and more. Have fun. I
will visit here from time to time to further the topic. References would
be great. Links? How to safe splat? Ways and means.
Mon Dec 26, 2011 10:39 am
Maybe some gentle motivations:
Positives:
1. Urban small-flight down-street landings on streets.
2. Irregular holey and rocky landing area.
3. Bog, marshy landing area
4. High grass with unknown under-top ground texture
5. Downwind downslope landing
6. Flatland long gliding maximization of glide
7. Downwind landings on friendly ground textures
8. Option mode
Care for the unplanned when other landing postures were first choice
http://www.youtube.com/watch?v=UCSKv0sD_HAGouging
small wheels on friendly landing ground texture. Near lifetime broken
neck, etc.; near fatal. Long-tradition aviation solutions are not
involved. Safe-Splat is not installed. False dependence on small wheels.
Greblo methods would have avoided. Well, still, some minor TCF ski as used
by early 1975 HG pioneer Tony Prentice would have done wonders in this
instance.
And recall the recent Jonathan D. downslope downwind landing.
Aspects to tease into the exploration:
1. Limit lines
2. Pilot-body arresting
3. Vertical impact non-rebound cushioning
4. Knee-cap over-plating
5. Neck brace
6. Face guard that is inset of the flow of the upper helmet surface.
7. Width of ski
8. Treatment of lower surface of ski
9. Potential of braking integrated with ski
10. Coming out of keel and forking and then flying cross brace
11. Staying lines
12. History of undercarriages in aircraft
13. What has been the cost in injury and fatality for not having a
Whack-no-More Safe-Splat structure on hang gliders?
14. The wiki needs some expansions:http://en.wikipedia.org/wiki/Undercarriage
15. This source may have some items for the topic:HERE
16. Physics comparison of wheels versus rollers versus skis
17. Material choices? Titanium? Fibers? Silicon? Ablation matter?
18. One or two or three runners or skis?
19.http://media.photobucket.com/image/grav
... C_0088.jpg
20. Catch?
21. Snag?
22. Breakage and then what?
23. Niche-activity repeatable desires? Non-consumption designs verse
one-time arresting designs?
24. Explosive positioning of parts?
25. Double-purpose of some birds' necks?
26. Visibility matters? See-through materials? Put out of the way after
launch; bring into place before landing?
27. Effect on training and practice sessions?
28. Primary glider single skids and their history
36. Curtiss:
37. Integrate with the twin-queenpost (triangle control frame (TCF) that
has been so popular in undercarriage for over 100 years) system by various
means?
38. Traction conveyor belt?
39.
40. ?
How about this idea (please scroll the picture as needed):
anti_whack_restraining_lines_300.png (54.38 KiB) Viewed 462 times
As the "whack" progresses, the lines progressively divert forward motion
into upward motion. They may also tend to bring the nose up as a
consequence.
I would be surprised if this hasn't been considered before because it's
such an obvious idea, so you might want to check around to find (and
post!) some old drawings of anything similar.
P.S. Thanks for making me think a bit!!
Mon Dec 26, 2011 7:23 pm
BobK,
I am assuming the diagram accepts a stopped basebar while the circle with
yellow and black is the pilot's body while the main hang line is with a
set of graduated arresting lines going to the aft keel? Is that correct
about the drawing? [ ] This is to be explored for its actualities; this
can be explored first with model splats and video. Parallel with that
visual study could be a mechanical vector analysis. Changing the degree of
basebar stoppage and the amount of arresting-line resistance would be
neat. A variable program changing the skid of the basebar at various
speeds with various wing masses and pilot masses could be a masters degree
project for someone. Just how much basebar skidding would change things
against how much arresting ... and the still swing path of the pilot would
be interesting. Some whacks nearly decapitate the hang glider pilot with
nose whacking on the head and neck for some gliders.
============
Another teasing image: skyview show two skids emanating from the nose and
splitting to the two skid paths. Patent number: 1358603
Filing date: Aug 10, 1917
Issue date: Nov 9, 1920
==============================
Patent number: 1306860
Filing date: Oct 9, 1917
Issue date: Jun 17, 1919
================================
Patent number: 1362511
Filing date: Mar 22, 1918
Issue date: Dec 14, 1920
JoeF wrote:
I am assuming the diagram accepts a stopped basebar while the circle
with yellow and black is the pilot's body while the main hang line is
with a set of graduated arresting lines going to the aft keel? Is that
correct about the drawing? [ ] This is to be explored for its
actualities; this can be explored first with model splats and video.
Parallel with that visual study could be a mechanical vector analysis.
Changing the degree of basebar stoppage and the amount of
arresting-line resistance would be neat. A variable program changing
the skid of the basebar at various speeds with various wing masses and
pilot masses could be a masters degree project for someone. Just how
much basebar skidding would change things against how much arresting
... and the still swing path of the pilot would be interesting. Some
whacks nearly decapitate the hang glider pilot with nose whacking on
the head and neck for some gliders.
Yes, the diagram shows the pilot's motion assuming that the base bar has
been completely stopped. Of course, the glider would also be rotating
forward which is not shown in the drawing (or animation), so you have to
superimpose an additional rotation on the drawing.
I didn't want to write a program to do it "right", but I did superimpose
my drawings to create the following animation. As you mentioned, this
shows the base bar stopped and the glider in a fixed position. In reality,
the glider would be rotating forward, but as it does so, the lines would
be dynamically shifting the pilot's attachment point rearward. Here's the
animation:
anti_whack_restraining_lines_f1.gif (35.09 KiB) Viewed 454 times
byterryJm»
Tue Dec 27, 2011 5:10 pm
beautiful, this may work, a combination of stepped hang points with flex
skids from wheels to nose plate? this idea is too fresh, need to sleep on
it, later, tjm
byterryJm»
Wed Dec 28, 2011 7:13 am
wrong! Too much drag, obstruction, complexity; let me be brief, ' Air Bag'
or, more taste less filling. Thanks again Joe, where would we be without
you? I still have a most inspiring copy of 'Low and Slow', SeeYaLater!!
byJoeF»
Wed Dec 28, 2011 10:34 pm
TJM,
Thanks.
1. Your air bags do need to be in the choice mix as the project goes
further. Air bags can be of various sizes and be placed in various ways.
Nose? Pilot? Front lines? Airbar roller? Huge airbag wheels. Much to
explore. Let's keep the airbag realm. Airbags are solutions for some Mars
landing, car crashing, etc. What about having harness or flightsuit being
valved to be explosive enlarged to stiffened pilot in a surround airbag
upon pilot choice or event via smart program?
2. It is not clear what is in your focus when you posted:"Too
much drag, obstruction, complexity; ".
Please tell what you had in your focus as target for that summary
discount. Generally, the topic is just getting started; only teasing
directions are posted, except the partial stepped arresting BobK items
under the assumption that the basebar catches and stops the basebar. Your
"flex skids" can be with low frontal drag profile; they can even be shaped
and positioned to be streamlines and even slightly lifting.
Leave open for the possibility of having device moved out of sight during
flight (just positioned during launch and during landing).
3. We are used to very open front (two cable simplicity). If a solution
involves some structure up front, the surfaces of such structure may be
advanced in many ways: Surface might be pixelized and be a reporting
surface. The report from the surface might be:
a. Airspeed by color changes
b. Temperature by color changes
c. Made to take on the color of the sky.
d. Made to report that which is beyond the surface by the invisibility
tactics that have been developed (device that reads the beyond and
duplicates the seen to the top surface of the ski that the pilot sees,
thus making the ski invisible to the pilot).
e. Holder of airbag (get ski and airbag in the one place, perhaps with
surface treatment as above)
f. Internet
g. Photographs of family and waypoints.
i. ???
More motivation:
TJM,
Please expand: "TJM
wrote: more taste less filling."
I
am not seeing or understanding the phrase. TIA on that.
====================================
So far, I am disfavoring my May 2011 skectch for canard sled as I am
favoring, so far, some ski situation that avoids traverse material that
could catch on brush and boulder. But I share now that prior sketch:
===========================================
Part of a solution might include non-rebound shock absorbing, as
rebound is drastic and is to be avoided. One direction of solving
could use the queenposts as holder of air to be used in the
non-rebound shock absorbing. The ski can be below the basebar by
substantial amount so that boulder and brush do not snag or catch the
basebar during impact action. The rear of the ski could be with a
posting that pistons into the queenposts (TCF downtubes). Then also,
after som ski impact some wheeling could get exposed or not. The
surface of the ski might be moving surface as conveyor belt or
teflonized or with ablative material. Choices to explore.
Other non-rebound tactics: bungee with piston cam catched to prevent
return or rebound until after landing event; then perhaps release cam
for reset for next flight.
On
pilot-body arresting:Limit
lines from the bottom of the queenposts (downtubes of triangle control
frame TCF) would perhaps be an option to the BobK stepped arrestors or
in combination with such.
Motivation:
==========================================
Another motivation:
============================
Sketch of a direction:
Man, you think fast, I'm only 2Parsect behide, and you,ve only been
teasing me? Please forgive the obscure since of humor, a little goes along
way, I'd like to be part of the solution; work, sleep, flying, singing,
all get in the way. We have so little time in this life, also; dont let me
get in the way, I'm just a survent, and a flash in the pan! seeYasoon,
Terry
bobk wrote:
JoeF wrote:
BobK,
I am assuming the diagram accepts a stopped basebar while the circle
with yellow and black is the pilot's body while the main hang line is
with a set of graduated arresting lines going to the aft keel? Is that
correct about the drawing? [ ] This is to be explored for its
actualities; this can be explored first with model splats and video.
Parallel with that visual study could be a mechanical vector analysis.
Changing the degree of basebar stoppage and the amount of arresting-line
resistance would be neat. A variable program changing the skid of the
basebar at various speeds with various wing masses and pilot masses
could be a masters degree project for someone. Just how much basebar
skidding would change things against how much arresting ... and the
still swing path of the pilot would be interesting. Some whacks nearly
decapitate the hang glider pilot with nose whacking on the head and neck
for some gliders.
Yes, the diagram shows the pilot's motion assuming
that the base bar has been completely stopped. Of course, the glider
would also be rotating forward which is not shown in the drawing (or
animation), so you have to superimpose an additional rotation on the
drawing.
I didn't want to write a program to do it "right", but I did superimpose
my drawings to create the following animation. As you mentioned, this
shows the base bar stopped and the glider in a fixed position. In
reality, the glider would be rotating forward, but as it does so, the
lines would be dynamically shifting the pilot's attachment point
rearward. Here's the animation:
anti_whack_restraining_lines_f1.gif
Bob,
As a diver (three meter board and six meter board.), skater (ice type),
and having been on a trampoline doing somersaults, it has been my
experience that tucking into a smaller ball off of the diving board or
trampoline will accelerate the somersault rotation speed. Opening up the
tuck will slow the rotation speed.
While spinning on the ice moving arms and free leg in closer to the
rotating axis of the body will accelerate the rotation speed.
In my estimation the tightening of each restraining lines will shorten the
arc that the pilot is traveling and would accelerate the pilot into the
keel tube.
What do you think?
Also would a KPL keel take the load of the restraint lines?
Bill C.
billcummings wrote:Bob,
As a diver (three meter board and six meter board.), skater (ice
type), and having been on a trampoline doing somersaults, it has been
my experience that tucking into a smaller ball off of the diving board
or trampoline will accelerate the somersault rotation speed. Opening
up the tuck will slow the rotation speed.
While spinning on the ice moving arms and free leg in closer to the
rotating axis of the body will accelerate the rotation speed.
In my estimation the tightening of each restraining lines will shorten
the arc that the pilot is traveling and would accelerate the pilot
into the keel tube.
What do you think?
Also would a KPL keel take the load of the restraint lines?
Bill C.
You may be right Bill. Conservation of angular momentum does increase the
rotation rate as the circle gets smaller. Your figure skating analogy is
an excellent example of that effect!! But there's a lot going on there,
and it's not clear to me what would happen. That's why I'm curious if
anyone has tried it before.
As for damaging the keel from the restraint lines, I think that might be
an acceptable tradeoff for many pilots if it saves them bodily damage.
How about a more traditional solution ... intentionally landing on fairly
large wheels with a tailwheel on the keel? Lots of tandem pilots do that
very successfully. I think that's also what Tad has advocated. It works
especially well if you're landing in a prepared field like Sylmar or
Crestline or Wallaby. My tandem at Wallaby was landed on the wheels and it
allows the pilot to stay prone and on the base tube throughout the entire
process.
Adding theTandem Traditional Tri-Wheel ( "3TW" or TTTW) option to the
spectrum as proposed by BobK!
Your note brings to fore:
1. Amount of awareness of landing area and its design
(this parameter can be from very open mysterious to very sure planned).
2. Rear-keel wheel could be spoon skid, hook for arresting catch, floating
spoon for water and bog and marsh
3. Forward wheels may be floating wheels for water floating option.
4. The TTTW direction has option to be combined with other Safe-Splat
options.
5. "When wanted" parameter comes in various means:
A. Single flight with high-certainty of landing-zone texture/design.
B. Mysterious landing-zone XC allowing soil or water landings,
upslope-downwind, downslope-downwind.
C. Low-mass explorations
D. Hidden when not wanted, but deployablewhen
wantedat
launch or landing sector. Out of sight and out of drag-making when not
wanted; but when wanted, deploy into position.
6. Groomed launch and landing areas versus challenge areas.
In some Safe-Splat scenarios there may be specific wishes for focused
braking means.
[[E.g. In deliberate asphalt urban automobile street of downslope landing
with tight options, like in avoiding reaching intersection; or at a tight
slope bottom where hazards exist. ]]
Braking?
Consider:
1. Ablative?
2. Deliberate gouging
3. Trigger rear plowing
4. Braked conveyorhttp://en.wikipedia.org/wiki/Conveyor_belt
5. Brakes on wheels or rollers.
6. Air brakes. Drogue? Super transformation of wing? Drawn curtain?
7. Arrestors pre-set in LZ.
8. Deliberate landing into air-held nets. "landing nets". Have kite system
hold up a large catchy net. Snag it. Airborne Safe-Splat ?
9. Very-giving perches?
10. Deliberate snag aerial bungee
11. Cushion field (foam, boxes, leaf piles, giving fencing, graded
curtains, ?
12. Long ice flat
13. Long slip-and-slide
14. Fly to flare landing in aerial horizontal catch net
15. Fly to snag aloft points on a large flying kite system.
16. Retro rocket
17. Explosively set soil anchor after skid is started and have resistive
payout line for braking
18. ?
