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.
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_HA Gouging 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?
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 29. Does LeBris have something for the exploration? 30. Garden of images? http://tinyurl.com/EarlyAircraftSAFESPLAT 31. Cam-lock shock absorber that locks-away rebound (prevent rebound; provide trigger for reset for next flight) 32. Damped impact versus undamped impact? 33. This study might have something for this exploration: http://www.isss.de/conferences/Amsterdam2003/IBV-STADIA(color%201xpag).pdf 34. 35. Pontoon skid
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. ?
Last edited by JoeF on Mon Dec 26, 2011 6:44 pm, edited 1 time in total.
How about this idea (please scroll the picture as needed):
anti_whack_restraining_lines_300.png (54.38 KiB) Viewed 32027 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!!
Join a National Hang Gliding Organization:US Hawks at ushawks.org View my rating at:US Hang Gliding Rating System Every human at every point in history has an opportunity to choose courage over cowardice. Look around and you will find that opportunity in your own time.
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
=================================
Last edited by JoeF on Mon Dec 26, 2011 7:49 pm, edited 1 time in total.
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 (35.09 KiB) Viewed 32019 times
Join a National Hang Gliding Organization:US Hawks at ushawks.org View my rating at:US Hang Gliding Rating System Every human at every point in history has an opportunity to choose courage over cowardice. Look around and you will find that opportunity in your own time.
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
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!!
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: ===========================================
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