dontbounce

hell, if the numbers pan out, Jeb has his answer. Just line the LZ with a bunch of mattresses - that's got to cost less than millions. (or do the wingsuit folk only get that 60mph fall rate when coupled with a substantial horizonal speed component?) The Mattresses arent a good real world example, because for the equation to actually work, deceleration must be constant and uniform, which it wouldnt be on a mattress. On an airbag it would be though... That is the goal of Airbag designers; to design an airbag that creates the most linear deceleration possible (spread the shock uniformly over a 18 inch distance) by allowing it to deflate at a predetermined speed. That way you dont have 10 Gs of deceleration for the first 17.5 inches and then 700 Gs in the last 1/2 inch(no airbag), it is more like 25 Gs for the entire 18 inches (with airbag). The most trauma the body will experience is 25Gs, instead of 700Gs. A mattress is just the first thing that came to my head. I actually did this as a kid (jumped from the roof of my dads toolshed to an old mattress) many many times, thats probably why. I recall that "missing the mattress" and landing in the dirt was a serious problem, because your ankles and feet would hurt for days and you wouldnt be able to jump with the rest of the gang for a week or so. On the mattress, you could jump 10 or 30 times before it was time for dinner. This is how stuntmen can jump from a 10 story building onto a 4 ft thick "airbag". It deflates rapidly, and he lands flat on his back. By the time he hits the bottom of the bag, he is almost completely stopped and he suffers little to no shock.

Yeah we have a "weather monkey". Ok Jimmy, stop throwing poop at the camera... By 2:00PM it was 78, and dark blue skies, with just a trace of wispy, high-level cirrus clouds. I should have jumped twice, but I had to pick my kid up from daycare in PHX. Oh well, there is always saturday.

Never went to high school.. Dropped out in the 7th grade. 4 yrs U.S. Army, 3 Associates Degrees, Bachelor of Management, Microsoft Certified Systems Engineer, Cisco Certified Network Associate. Need a firewall that will keep out the best hackers in the world while allowing 100,000 users to surf the web? I'm your man. Calculate the area of y=x squared from x=0 to x=1? I remember it is .333 but doing it on paper? Yeah... Not since 1992, jacko. Business Calculus, Matrices and Linear Programming, Chemistry, Programming, Network Engineering, thats all. Doesnt help me much here. Your point is?

Thanks for the tip. I will try that for my own benefit. Man, this internet thing is great!

10 minutes in the --- wind tunnel -- will probably sove your problem. (not to step on Sandy's toes) See a pattern forming with the "wind tunnel" comments? It isn't hard to stay stable, you just need to get used to the sensation, and learn how to swim through the air. Either you will learn to straighten your leg, or you will be able to compensate in other ways such as body position. Either way, you should be "fixable". If you can't master it in 10 minutes. Buy another 10 minutes a week later. You WILL figure it out... It just takes practice and determination (a hefty bag full of cash doesnt hurt either). :) The great thing about the tunnel is that you remove the fear from the equation and it is a lot easier to learn when you arent scared. Heck, it's fun too, as long as you dont mind smashing every part of your body against plexiglass over and over again... Heh heh! Training how to free fall 50 seconds at a time (with a gallon of adreneline in your system) is a real bitch, especially if you wait days or weeks between those 50 second training times. Plus, you psych yourself out by thinking "I am going to go into some sort of spin and freak out" right before you jump. If you can, go the the gym and get your "bad" leg ripped. It will help you here with this issue, but in other situations as well (like landing), ninja kicking people upside the head when they cut you off on your base leg, etc. Cheers! P.S. I did 10 minutes in the tunnel, and I have only minimal problems with free fall stability (need to keep my legs at 45 degrees). I may do it again. It can't hurt. P.P.S. It has been my experience that if I remain ultra aware of my altitude, I don't get scared anymore. It is kind of nice. Not shitting your pants in free fall makes for a lot nicer canopy ride. I may not get much done up there, but I manage to control myself in FF and land softly which is pretty good for this stage.. Also, avoid coffee, soda, cigarettes, cociane, methamphetimines, ritalin, ephedra, epinephrine, albuterol inhalers, scary movies, bosses, bitchy women or anything else that gives you an "up", or makes you stressed out. Both "uppers", and "stressors" have the same affect on your body physiologically; they release adreneline into your blood. When you leap, if you are already at 70% of max capacity on adreneline, when you jump it will go to like 150%, and you lose your grip and freak out.. I failed Aff Level 1 : no pull/yard dart. If you are 10% capacity, then when you jump it goes to 80% (same increase, but ambient levels are lower) and you maintain a reasonable level of control of your thought processes. (at least for me, everybody is different). Did you know strenuous exercise releases "noredreneline" in your system? It is your body's natural antidote for "adreneline", also produced by the adrenal glands on your kidneys... So try doing some pushups, curls or practice those ninja kicks right before your gear up and you will feel a lot better physically (butterflys, weak legs, dry mouth, sweaty palms). It also works AFTER the jump if you have problems sleeping that night like I always do... When I jumped at Eloy today, I could have taken a nap on the way up if it weren't for the gassy bastards on the plane. ;)

Yeah. It has been FREEZING here in Phoenix. down in the 50s at night, and highs in the 70s... Brrrr...

YEAH!! Fri Feb 24 Sunny 77°/41° Sat Feb 25 Sunny 81°/45° Sun Feb 26 Partly Cloudy 86°/50° Mon Feb 27 Partly Cloudy 86°/50°

If my math is correct, I weigh 16.5 stone. I am not (really) fat, just have thighs like tree trunks and a 50 inch chest. I jump a student 280 (I am very new) and the landings are nice and soft for me (when I dont screw up). It is probably a matter of finding a large DZ that has a couple of rigs made for mutants like us... ;) Call around, I am sure you will be able to jump somewhere. Don't lose weight. Your beautiful just like you are (and you will just make me look fatter) I probably have a hundred jumps to go before I start playing around with small conopies, or crazy high performance stuff. For now, the one above my head slows me down enough so that landing doesnt hurt... Thats good enough for me. If you are just looking to get some Jumps in, look for a school that will cater to you and you will find something. Worst case scenerio, you might have to use a tandem rig. But hey, whatever gets the job done right? Free fall is the real fun, and the parachute is just a nessecary evil...

Thanks guys! Good enough for me!

I get the flaring too late part. Been there, Done that You stop too high.... Then what, it is kind of impossible to "stop" until your sneakers are on the dirt, right? I can see that all motion could be stopped temporarily, (kind of hover action) but what happens then? Do you drop like a rock? Does your canopy slide to the front, or to the back? Does god smote you for being a fool? Thanks for the quick reply!

Sorry for the 1 point question from the 2 jump chump. What happens if you flare too early? Too late? Thanks! Its a skill I will need in the next 10-12 hours, so your quick reply is much appreciated!

Eloy is the bomb...

yep... See, not everybody forgets what its like to be new... Landing #1 was hard, in the dirt. Almost broke my wrist (hands out to catch myself) and got a mouthful of dirt (and I got a tubleweed tangled in my canopy) Landing #2 was in the grass. Nice and soft on my ass. A big improvement if you ask me... Landing #3.. Well Ill let you know. It's tomorrow. Cheers, you crusty old dogs...

Carter has a point. With 99.7% of every Arab on the planet thinking the "Bushies" are out to "git em", Bush is probably just throwing a little KY Kelly on the Arab Demographic you know?... Afganistan in 01, Iraq in 02, Iran in 06 and maybe Uzbekistan in 07 (if they cop an attitude). 25 cent gas and Hummers for everybody!... "Hey Dick, how many army guys do we have left?" A cowboy wet dream. It probably does him some good to at least take a shot at not looking like some sort of Nucular Capable Christian Crusader bent on destrying the muslim world... Probably not a wise move politically though. Somebody should have caught that one. Lets see, libby is under indictment, Rove is down town testifying in front of a grand jury, Cheney is drinking and playing with firearms (it's Lawyer season ya know), and Georgie is listening to "hooked on Phonics" in the oval office, while mouthing the word "Nu-Ca-Ler" to himself. Who else is left in the white house except the receptionist and the cook? It was probably "Larry" the guy in charge of telling the president about major hurricanes that destroy large american cities (sorry boss), or maybe "Jimbo" the guy in charge of double checking WMD Intelligence (my bad)... The democrats have been itching for some foothold in the National Security angle. Now they have it.

QuoteWhere they tried to burn the body is about 7 miles from my house If it was windy that day, you probably thought your neighbors were doing BBQ. You were like "sniff. What is that? It isn't steak... It isn't chicken... Hmm. Oh well.. "

Yeah, I would think getting gang raped in Prison for the next 85 years and cant be much better than death... I think the death penalty is too quick.

Well, considering the way that replublicans have had their asses handed to them in the last 6 months(numerous felony indictments, numerous investigations, shootings, etc, etc), it would be prudent for Bill to try to become more of a centrist in his thoughts wouldn't it? Besides, it has been my experience that Fox News and the Republican propaganda machine will say whatever fits with the mood of the country at any given time. If 70% of the country wants to kick some ass (e.g. after 9/11) then they are "eagles" or "hawks". If 70% of the country wants out of Iraq because our children and our brothers are getting killed every day, suddenly they become "diplomats"... They are a crafty bunch that can appear to the uninformed public to maintain a consistent message while shifting the underlying logic supporting the message constantly. Like an oil painting on a waterbed. The end result is the same, but the rationale used to come to that conclusion shifts every time their argument is exposed as flawed logic (the Iraq - 9/11 connection), incompetent (Katrina was really TWO natural disasters! Thats why we werent ready!) or even downright dishonest (Downing Street Memo/WMD/Cia Leak/Iraq War). The worst part is, 90% of America is too busy watching "American Idol" to care. Give them a slogan, and some sparkly brochures and they will revoke the bill of rights... Sounds like somebody is being a "flip flopper"... For all of you Republicans lining me up in your crosshairs, Fire away... I won't cry...

Your lower back gets really sore after about 7 minutes... Maybe it's because I was a newbie.. Good luck with that! Oh yeah, and when your lower back is exausted, it makes it really hard to stay stable, so get ready to bounce off some walls... Man that sounds fun! When your done, you will probably be able to fly like a bird though...

The voice of experience... Damn I hate it when people talk sense into me.

I disagree. Airbags in cars are actually very small BEFORE they are used... :) You could make them even smaller if you vacume sealed it... Like the infomercials where you vacume the air out of a bag of clothes to save space... bag http://www.lanl.gov/quarterly/q_sum03/images/composite_draft_bag_a.jpg another bag http://www.lemurzone.com/airbag/images/driverairbag.jpg propellant http://www.kaldi.com/graphics/charger_0084.jpg CO2 cartridges http://www.adventureracingconcepts.com/prod/bike/tool/inflation1.html

Thats great... Balloons...

so, (roughly) when you leave the plane, you travel 704 feet in the same direction as the plane before your lateral motion is negligible. So, at 2000 feet, you would have to drop the dummy 800 feet or so before you passed over the drop zone to make sure it landed in the right area and didnt take out a barn or something.

OK. So how do the pilots know where to drop you to make you land on the DZ? Wild ass guess? Or does the free fall lateral motion not make nearly as much of a difference? Assuming a 180lb "object", roughly shaped like me going "aaahhhh" falling toward the earth... I have a buddy who is a pilot, and I want to do some experiments on deceleration forces from a terminal impact (and how to mitigate those forces using things like high drag devices, airbags, etc). I dont understand how we can drop an object the size (and weight) of a vw beetle on the surface of mars at almost 100mph and not even scratch the paint on the lander, yet the same technology is not used for divers like us... I know this is a sensitive subject, but it is one I am interested in, and one that should be addressed with the best available technology. Not thinking about it until you have a double mal is NOT a solution. Here is something I have been working on... ------------------------------------ A Diver hitting the ground (going in) could be approximated from the sheer physics involved to a driver slamming their car into a brick wall without wearing a seatbelt. The forces are the same, and are all related to the rapid deceleration of a body in motion. Simply stated: The fall doesn’t hurt you, it is the sudden stop at the end! Anybody in the auto industry will tell you that three main factors determine the destructive forces on the driver: 1. the speed of the driver right before the event (initial velocity) 2. The mass of the driver 3. The stopping distance (from full speed to complete stop). When we deploy our main, we slow from terminal to about 10mph over a period of 3 or 4 seconds. When we “go in”, the same deceleration occurs, just over a much shorter time frame. This is explained: Force on Driver in Example Car Crash http://hyperphysics.phy-astr.gsu.edu/hbase/carcr2.html#cc2 and CHAPTER 24 AIRCRAFT ACCIDENT SURVIVABILITY http://www.iiimef.usmc.mil/medical/FMF/FMFE/FMFEref/fs_man/CHAPTER%2024.html and Gas Laws Save Lives: The Chemistry Behind Airbags http://www.chemistry.wustl.edu/~edudev/LabTutorials/Airbags/airbags.html and Mars Pathfinder Project Information http://nssdc.gsfc.nasa.gov/planetary/mesur.html Using the calculator from the 1st link, I punched in some test figures and got the following information: A human weighing 180 lbs traveling at 53 meters/sec (120mph) decelerates to zero meters per second in .1 feet (1 ½ inches). (going in, no canopy, minimal drag, hard ground) Force exerted on the body: 867,075 lbs, or 433 tons. A human weighing 180 lbs traveling at 53 meters/sec (120mph) decelerates to zero meters per second in 1 foot. (landing on a mattress for example) Force exerted on the body: 86,707 lbs, or 43.3 tons. Lesson: distributing the deceleration over a 1 foot area lowers the destructive force on the body by 90%!! A human weighing 180 lbs traveling at 53 meters/sec (120mph) decelerates to zero meters per second in 2 feet (landing on two mattresses for example). Force exerted on the body: 43,353.75 lbs, or 21.6 tons. (this is about twice the force of a 60mph car crash while wearing a seatbelt) A human weighing 180 lbs traveling at 26.82 meters/sec (60mph) decelerates to zero meters per second in 2 feet. (landing on two mattresses under partial inflated canopy) Force exerted on the body: 43,353.75 lbs, or 5.41 tons. (the force of a 15mph car crash with no seatbelt) Painful yes, but Survivable… This is less than 1/100 the force of going in at full speed with no cushion. To greatly increase the likelihood of survival, two of these factors must be compensated for. 1. Speed at time of impact 2. deceleration time If you can decelerate the jumper from terminal to 60mph using some sort of "quick deploy" drag device behind them (like an auto airbag with a flat shape and a LOT of surface area, or a "mammoth drogue" powered by a CO2 canister like in BB guns)), and give them 1-2 feet of padding on the head/torso/abdomen/hips (such as an auto airbag, also power by CO2 cannister), they would experience 1/100th the force of impact as going in hard. Additionally, the quick drag device would force them into "belly down" to distribute the force of impact over the largest surface area possible. It is possible to develop some sort of "last chance" system much like an aad that would deploy at say 150-200ft at a speed of >75mph. Since the Cypres shuts off at ~130 feet, this could make the difference between wearing a couple of casts for 5 weeks, and... 1. Develop it cheap 2. Develop it with minimal weight and size. (front airbag could be as small as a pack of cigarettes attached to your chest strap) (drag device could be smaller than a cigar box, directly above the parachute, or one the size of a coke can on each side) 2. design it to be retrofitted onto existing harness systems 3. design it so that it doesnt interfere with the operation of the control systems (or the two canopies) in case of accidental deployment. You could cut the fatality rate by a lot... Maybe like 20%-40%. Take a look at the fatality database. Look for "low pull", hard pull, late reserve activation, double mal, etc. It wouldnt fix some guy loaded at 3:1 doing a hook turn at 90mph 50 feet off the ground, but it would fix a lot of other problems. You could probably build something like this for less than $300.00 if you used readily available technology.

So it would be 100% lateral 0% drop the moment of the drop, 90% lateral, 10% drop after 1 send, and so on? Thanks for the info... Do you know the average speed of say an otter on a drop run (relative to the ground)?

yes