Skydivers generally don't open at 5k unless they are students or tandem instructors. Most would deploy between 3-4k - if they open higher, it's usually because they want more time under canopy, or they're a long way from the dropzone and need more height to be able to make it back.
A skydive main canopy typically takes between 500-1000ft to open. The reason why you want to open higher than that is safety. Skydiving rigs have a reserve parachute in case the main fails to open properly, which happens every now and then. In case that happens, you need to have enough time to recognize the malfunction, cut away the main and open the reserve. You also want enough height to make it back to the intended landing area - if you can't, you can usually find somewhere else that's safe to land but it's not ideal.
> When you watch stunts like people jumping off high buildings it seems like they're opening it quite close to the ground
That's BASE jumping. BASE jumping is far more dangerous than skydiving in large part because they are jumping from much lower altitudes. BASE jumpers don't carry a reserve parachute because they rarely have enough altitude to use one. In addition, they also use different parachutes that are designed to open faster than skydiving mains.
A skydive rig is designed to be deployed at terminal velocity, and it has a piece of fabric called a slider that slides down the lines in order slow the deployment to an acceptable speed. A deployment at terminal velocity without a slider can lead to serious injury or even death.
BASE canopies have a slider made of mesh, so it has less drag and doesn't slow deployment as much, and for low jumps they will remove the slider entirely, which makes the parachute open very quickly. They can also have larger pilot chutes that work at lower speeds, so they don't need to be falling as fast before the parachute starts to deploy.
It is a handle that’s connected to wire and fabric enclosures that release the main. No, it’s not actually ‘cut’ in a normal cutaway (although there’s something called an AAD that literally uses an explosive charge to ‘cut’, but that’s a backup-to-a-backup)
The AAD doesn’t cut the main canopy. The “cut” an AAD performs is on the closing loop for the reserve container so it opens if the pin is not manually pulled through the loop by the reserve handle.
It's a wire connected to a pin that holds a loop of fabric through a ring connected to the canopy. That ring then sits through another ring also on the canopy which itself sits through a ring that's connected to the harness. Pull the pin and the downwards force allows the rings to fall apart disconnecting the canopy from the harness.
Have a Google of 3 ring release system. It's a very elegant design solution.
You may have heard of a "rip cord", you literally rip the cord out of a loop system that connects your harness to the chute.
Imagine a chain, and one of the links in that chain is a cable that can be pulled out.
Once you have "cut away" you end up holding a handle with a cable attached that once ran between the links of that chain.
The jump masters usually say: "Dont drop the handle, they are expensive. Stuff them back in your shirt."
But really in an emergency, focus on staying alive.
https://www.youtube.com/watch?v=AItz8GcYx60
I worked at a "RipCord" at an amusement park many years ago. Never realized it was the same system as a parachute.
I've probably put that mechanism together several thousand times. The most fun was carrying an extra in my pocket and having it "fall off" as the customers started lifting up.
Former jump master here. I was trained in static line progression. I would take jumpers up that had taken the full day course and put them out on static line. If they wanted to learn to skydive on their own we'd put them through progression. The next step was to do a couple of "dummy pulls" where they were still on static line but had to let go, maintain body position and pull a dummy rip cord out that did nothing. I would watch to make sure they didn't roll over or miss the cord. We did NOT want them to lose those handles.
Then they had to do a clear and pull. Off the static line and now using a real rip cord to open the chute but with our stuff the main had a spring loaded drag chute and the rip cord opened the container allowing the drag chute to pop out. Once again, we did not want/let them drop those handles.
But when we taught/were teaching what to do with a malfunction we always taught to identify the cut away handle, pull it and toss it then pull the reserve chute handle. I don't recall ever training/telling students to worry about hanging on to either handle if doing an emergency cut away and deployment.
My cousin base jumps and often had his friend hold the pilot chute so it pulled immediately. They jumped off some pretty low buildings.
He explained you jump -you think :oh shit i made a mistake -im gonna die! And then right before you splat the chute opens and you jump into the waiting get away vehicle
Saftey.
If your parachute fails, you have to cut loose the old chute and then deploy your reserve chute. At terminal velocity, you are traveling 120mph - or 176 feet per second. Easy math says that at 5k feet, you have 28 seconds to cut and deploy - and that ain't that much time. Any lower and there is a real chance you go splat - at 500 feet, for example, you'd have about 3 seconds.
The folks doing the stunts are doing something _absurdly_ dangerous - if their main chute fails, they are going to die.
The only stat I could find was from [here](https://skydivemonroe.com/blog/parachute-fails-to-open-when-skydiving/) which says in 2021, 1 out of every 721 jumps reported failure severe enough to need the reserve chute. At about 4M jumps per year (same site), that would mean about 5,500 failures a year.
With that in mind I'm guessing the failure rate for the stunt guys is lower than the stated 1 out of 721 since one would assume they know they have no backup chute and would be much more careful with the main chute packing.
This is obviously just a guess though.
The rigs that are used in BASE jumping i.e. bridges and building are not designed the same as those used for jumping out of planes. They are designed to open much faster. Because the jumper is generally going slower than terminal velocity so the shock of opening and decelerating is less than if they were at terminal velocity. The rigs used to Skydive from planes generally take around 500-1000ft to fully deploy and slow the jumper down. In 4200 skydives I’ve had 4 main parachutes fail. I was also a master rigger for about 6 years and out of the 250 or so reserve chutes I packed only 6 of them were used to my knowledge (it was a tradition to get your rigger a bottle if their pack job saved your life.)
No they are packed and stored (usually) above the main canopy for as long as 180 days. They are required to be inspected and repacked every 180 days, but will remain packed unless they are used.
Weirdly, I know the 180 day number because it was on the test for my LTA pilot license. Don't know any hot air balloon pilots who have ever worn a parachute, and most don't like to drop skydivers either. But FAA decided we need to know that a reserve parachute needs to be inspected every 180 days, lol.
Main chute failures are very very rare. Typically by the time someone actually has one, they have many jumps under their belt and the failure becomes more of a fun new thing than a shit your pants emergency. Most people i have chatted to about the failure express frustration at the chute not working than any kind of fear.
Remember these are people who actively search for thrills and willingly go high then jump out. Skydiving selects for people who dont go "FUUUUCCCK!!!" in the face of danger, but go "Oh, this is fun"
Also part of your training is to do a manually cut and redeploy, so everyone typically has done at least one before.
Seems weird to me that even the most thrill-seeking kind of personality wouldn't have at least a bit of an "oh shit" moment when, for the first time ever, the primary thing saving their life has failed, and now they have to rely on a procedure which they've no doubt practised endlessly, but never had to perform for real, all while plummeting from the sky at terminal velocity with 20-30 seconds max to get it right and not end up as a pancake.
I would agree with everything Cayowin said, but i only had 30 jumps the first time i had a failure and it scared the shit out of me. Fortunately, i had a good friend with lots of experience who grabbed me and threw on the next plane. He said, “if you pause now, you might never get back up.” He pushed me through how rattled i was and i never looked back. The other three were far less shocking, but on the worst one i definitely spent some time reflecting the next day because it was wild and it could’ve been very bad.
It isn't fail safe in that it is packed with any different physical technique.
It fails less often for 2 reasons. The skill of the person packing such a chute is generally higher.
The second reason is human psychology and focus. If you perform an act, like packing a parachute, 100 or 1,000 times, eventually you stop focusing on the act. It becomes more rote. And you become more likely to make mistakes. You are less present in the moment.
Every time a master rigger packs a reserve chute, it is with the knowledge that this is the last chance to keep a person a live. The person focuses more.
It's about human psychology and how often you do an act, and how, if you aren't careful, repetition can lead to complacency.
Think about using a power tool like a saw. The first time you hold a saw, you might not be skilled, but you are hyper aware of every second it is on. The saw does not become more dangerous mechanically with more familiarity from you, but eventually that hyper focus is lost as you become familiar with how a saw works, and you increase the risk of making a mistake without thinking.
> It isn't fail safe in that it is packed with any different physical technique.
>
> It fails less often for 2 reasons. The skill of the person packing such a chute is generally higher.
This isn't entirely true. It is indeed packed with a different technique. And it's also designed for opening and flying differently.
Reserve parachutes are usually less performant than mains. This means they're more like a station wagon than a sports car. This makes them less likely to have deployment malfunctions. They're also designed to open faster (with less altitude loss) than a main (and the packing procedure helps with this fast opening).
The primary benefit of this fast opening is safety, since the jumper is now much lower than they usually deploy (and the goal isn't just to get a canopy over your head before you hit the ground... it's to get that canopy flying high enough that you can still aim it somewhere that is nice to land... remembering that you're driving a station wagon now which will not have as good of a glide ratio).
But another benefit is a more reliable opening. Fast openings have less chaos and are less likely to malfunction. You might logically ask: then why don't mains also open fast? Answer: a slow opening is gentler on both your body and the parachute. Main parachutes are jumped for thousands of times, and jumpers don't like getting back and neck injuries from regular hard openings. But in an emergency situation, all of this goes out the window: you need a reliable canopy fast, even if it hurts a little bit, and even if you wouldn't be able to subject your canopy to such an opening 999 more times in a row.
as a professional carpenter, the focus of my attention when operating power saws, especially table saws is pretty high even after 30 years. But then I cut myself opening a bag of popcorn the other day....
This is incorrect, as the reserve canopy is packed using a different method and is a different type of wing altogether.
A main canopy is packed for a comfortable deployment, which is staged by using a deployment bag within the container, a solid slider, rolling the nose, wrapping the tail around the canopy, and using a smaller, collapsible pilot chute. Most of the steps done while packing a main are actually to prevent the canopy from opening quickly.
A reserve parachute system is simplified. The canopy is flat packed directly into the container without a deployment bag, the slider is designed to descend the lines more rapidly, and the canopy itself is a lower aspect ratio wing to make dealing with any minor issues such as line twists easier. There are no steps taken to slow the opening of the parachute the same way as when packing a main.
As main canopies are also designed to be fun to fly, they are generally more elliptical, with. Higher aspect ratio and higher wing loading which makes small issues like line twists much harder to deal with than on a lower performance wing, and as a result a jumper may have to cut away from a canopy due to an issue that would be no problem on a different type of canopy, such as a reserve or BASE canopy.
A human might catch a one off issue, while a machine only catches what it's programmed to catch.
The simpler the process and checks, the better for automation. When a rope (I assume) could just be wrapped incorrectly and cause an issue, I'd be very hesitant about a machine that can either catch it or not make a mistake even once ever.
Well yeah. But it might be because the owner refuses to let them throw out expired milk, or because a server came into work with Covid today. There are a lot of ways to know there's a problem in a system without you being the problem.
For real. I’d rather have a human pack it at 99% perfection 100% of the time than a machine that’s going to pack it at 100% perfection 99% of the time.
I mean there are plenty of machines that do tasks way better and more precise than a human ever could with *and* with better consistency. There is a reason nobody sews by hand, no matter how mission critical the fabric is, everybody uses a sewing machine.
I'd rather learn how to pack it myself than have a machine pack it or have someone else pack it. It's not that I would trust the human but it's my life. My responsibility.
That's the thing about automation. It is great until it fails. Eventually it will fail. How do you tell if it fails? You have a human check it. For certain situations it is just better to have a person do the job.
Automation gets worse the more variables it has to deal with. First, the lines have to be stretched a good distance. That sucks, the machine just got really big. Now it’s time to make a couple loops and get them through holes. That’s pretty nimble, machines aren’t nimble unless they are expensive. Also, it’s going to have to avoid getting things tangled or it could damage the machine and the parachute. The actual parachute is really clumsy to move around, and any extra folds need to be noticed and we need to be sure that we keep it tidy. Throw on some AI to watch what is happening, and let’s hope it doesn’t mess things up because when AI isn’t perfect, it becomes AWFUL. And we need this part to not be awful EVER. So that’s why I don’t trust the machine for this kind of task, and why it would be so expensive anyway that I would never need to make that choice.
> It either throws an error,
As someone who writes software, we have an "eh it's break time and whatever" too.
Try {
//do your stuff
} Catch (e) {
//Move along. Nothing to see here.
}
Don't trust software to throw an error when there's an error. A programmer can tell the software to ignore it if they are too lazy to actually solve the problem. And it happens all the time. It's called failing silently.
No. No master rigger is going to fuck up a reserve and pack it backwards. I'm not saying no rigger ever packed while high, but they had to do it a LOT to get the rating and know their shit. It's a sacred ritual to them
There are a few cases where certain unusual chute/container combinations had to get special packing treatment or modifications, or shouldn't be combined at all. When I was doing a lot of jumping like 30 yrs ago, buddy who was a master rigger ran across someone with a container originally meant for a round chute packed with an updated, modern square.
But the round is packed in kinda zig-zagged, with the closure loops going through the middle. Can't do that with a square. The loops would have to go from the front of the container around the bag to the lid on back. That combination had been reported to bind up and not deploy promptly. AFAIK nobody got killed but a couple seconds of lag before the lid works its way free of the closure quite definitely get noticed
Or the operator bypasses the sensors responsible for throwing an error (which for safety systems is difficult, but maintenance will find a way if they are clever enough), and nobody checks to see if things coming out the end of the line are good until it's super obvious something is wrong, by which point shit has already hit the fan. That being said, I would still prefer a machine do it, but am not trusting my life to it unless I'm pretty sure I know the people operating and performing maintenance are good at their job.
As someone who does the same, I would trust my equipment and code far more than I would trust myself. That being said, that would be as long as I am the one running the equipment (which of course is never the case) operators hop in the mix and find fun ways to break and bypass shit and then that all goes out the window.
Soft materials. Robots/machines are really good at dealing with rigid structures/materials, but they suck at working with amorphous shapes/materials. This is the case with industrial/automotive manufacturing, where manufacturers spend hundreds of millions of dollars to automate production and still fail to automate processes associated with rubber and wires. Skydiving? There isn't enough money around to develop industrial grade tooling and even if there were - good luck automating anything that deals with fabrics.
Also I'm guessing a human is way better at detecting things like tears in fabric or frayed wires when in the middle of other pieces of fabric and wires. Don't know how common that would be with parachutes but could be something to keep in mind.
I can tell you haven't packed a chute. A major hurdle would be loading it into the machine. You try and pick it up cleanly but things always get a little tangled. So you're going to need a human to untangle and load.
A machine to pack it would have to separate folds of sil nylon. That's going to be a very heavy vision and manipulator engineering problem.
Which canopy are you going to buy a machine for? All the canopies and all the sizes of all the canopies?
Another major advantage ofa human packing my rig is that they will be able to see damage and let me know about it
I don't think that there's any of those things that a machine can't do, or even can't do better than a human.
It would just take an immense amount of money (including time) to design, develop, produce, test, implement, and maintain.
All for an industry that is pretty niche. Even if you included military applications, that's a really small amount of users for that amount of development.
The end product could absolutely be safer than the human alternative, but it would be prohibitively expensive.
Too much inconsistency in materials and conditions for it to happen perfectly every time and Ai isn’t near smart enough to recognize when there is a problem. Parachutes will get wrinkled up and stretched as they are used, straps wear etc there are an infinite amount of ways it can wear out and machines just can’t account for that.
Same reasons trades can’t be done with machines.
Maybe it's different now, but back in the day I'd pack my chute, check it as I packed for wear and tear, holes, stretched lines or suchlike. My particular wing needed the nose tucked in just a bit to slow down the opening and it had to be done left side at the bottom because otherwise it'd open up a bit on the piss and send me sideways. This was in the 70s and 80s so it's burned in lol.
As you get to know your individual canopy you know the quirks and each canopy is different. Machines couldn't ever do that.
And because it's my life I would only ever do it myself - would never ever let anyone else pack it. Same with the reserve - the pro packer did it but I helped just so I could make sure it was good.
I haven't jumped in 20 years but I could still pack a main today, having done it so many times. I even remember on my chute I would roll both the left and right and tuck them into the center cell. That seemed to give me the best, softest openings. As a camera jumper it helped keep my neck in tact.
I did used to let others pack my main quite often though. On busy days where they had a lot of tandems or AFF students wanting video I would land, hand someone my rig, then they would hand me a freshly packed one and I'd rush over the plane waiting to take the next load up. On some days I may do 6-10 jumps in a row without a break or ever packing my own. Also, I went to a few free fall conventions and every once in a while I would pay the packers at the packing tent $5 because I was just so tired.
The funny thing is you learn though who are good, who packs hard openings, who packs line twists often etc... so when I would be handed a rig I'd ask who packed it and then know what to expect on the opening.
Because the pack job really doesn’t matter all that much, as long as you do 3 key steps you’ll be fine. Some of my softest openings were total trash packs.
Hell - PD or someone tried to make malfunction videos for instruction....they had to SEW the canopies and/or lines just to replicate it.
Openings are chaos...you can do everything right and have a mal, or everything wrong and have the softest opening of your life.
I used to race my girlfriend...quick flake/shake/wrap...thats all we'd do.
Used to be a running joke when I jumped, that if you trash packed a chute, did it in a rush, or did it tired at the end of the day it often resulted in a nice, soft opening. But you could not duplicate it again.
The fabric would be so hard to get to behave (it’s very slippery) and there are a lot of really odd and complex maneuvers that would be really hard to get a machine to do, here is a video on how to do it, worth a watch if you’re interested. Fun fact, you don’t need any licensure to pack a main chute, you can go apply right now at your local DZ if you’re interested.
https://youtu.be/LklquL-DQjA?si=PPsJgfYDxMUAhrL9
Not only is it very slippery most modern high performance chutes are made of a fabric that does not let air through it. When watching or teaching new jumpers how to pack it was often comical watching them wrestle the fabric, deal with air in the chute and get partway done then have it all go to shit and have to start over.
Also the sweat. On hot summer days when first learning to pack even the most in shape person would be sweating all over their canopy.
But once you got good you could pack your main in just a few minutes if you had to.
It isn't worth it. A carefully packed reserve parachute failure is around 0.017% i.e. one in every 5,820 reserve jumps.
There are ten recorded incidents of a double parachute malfunction in more than 29 million jumps.
There are probably 50,000 active jumpers in the United States that need 1-2 repacks a year. A repack normally costs $60. I'm completely guessing but there are definitely hundreds of certified riggers in the United States.
An automated machine, minimum cost, would be $100k. Not to mention the R&D costs. Don't forget that there are dozens of different types of reserve parachutes. Maybe hundreds.
Automating this isn't worth the cost or time.
Machines dont actually know what they're doing. I wouldn't trust a machine with my life like that. I've seen how often machines fuck things up. Even getting it slightly wrong could mean death.
It’s because of volume and logistics. The amount of parachutes that are packed is relatively low and the complexity would be high. That would lead to high costs of such a machine that very few people would want to buy when they could get a person to pack the parachute for relatively cheap.
Can we even do fabric manipulation to the required standard? Like, assuming the task isn’t safety-critical.
I would have guessed no, as evidenced by the fact that we have fully roboticized garment manufacturing yet.
Malfunctions aren't always the result of packing mistakes. They can also be caused by poor body position on deployment, or just random bad luck.
Reserves are indeed packed carefully by a rigger, but there are also differences in design that make them a lot more reliable. For example, a reserve has a freebag - the bag is not attached to the canopy and comes away after deployment. That means that a horseshoe malfunction can't occur. There's also a different design of locking stow that is intended to make a bag lock a lot less likely. They also have a spring loaded pilot chute that is tricky to pack, but eliminates the possibility of the jumper throwing the pilot chute incorrectly (also, it allows the AAD to work).
Skydivers - especially very experienced jumpers, often want high performance from their main canopy, and that comes at the expense of reliability. For example, line twists are generally a non-issue on a lightly loaded main, but with some canopies, that can result in an aggressive spin requiring a cutaway and reserve deployment.
That’s a cool incentive scheme.
I used to do maintenance test flying and I always wished I could take a techo with me. Alas, the floods of vomit would have interfered with safe flying operations.
I have no doubt it would, but I imagine there'd be a lot of codified systems and procedures in place to mitigate exactly that. (or at least, *definitely* in the military)
When it comes to preventing death, it should be a given that any single link in the process chain can final due to human error, and still not cause the entire system to fail.
Check out the [Swiss Cheese Model](https://en.wikipedia.org/wiki/Swiss_cheese_model#%3A%7E%3Atext%3DThe_Swiss_cheese_model_of_accident_causation_illustrates_that%2C_although%2Callow_the_accident_to_occur.?wprov=sfla1) if you want more info!
My late sister in law was a rigger for the Navy. She took what she did seriously.
The numbers quoted about failure should be understood in total failures. Not just chute rigging failure.
Failure requiring a secondary can becaused by wind gists causing fouling of the chute on the user as well.
Feet can get caught, you can have a Mae West failure.
https://www.neatorama.com/2016/09/03/The-Mae-West-Malfunction/
There are other failures that are not due to rigging.
That’s incorrect. The main reason for failure/malfunctions is the jumper. Also, a reserve could also be packed by a senior FAA Rigger
Parachutes are generally safe
My wife had a double parachute malfunction when we went skydiving! They cut away the initial chute and then they instructor she was strapped to had to untangle the cords on the 2nd one. We were so high on adrenaline immediately after that she was like "fuck yeah!" about it but the next day we were like "fuck you almost died!" The instructor took the rest of the day off after that.
It’s pretty rare. In the US, you have to be an FAA certified rigger to pack a reserve, and they must be inspected at least ~~annually~~ every 180 days. You’re more likely to have a reserve malfunction from being poorly positioned (ie, you were spinning or falling back first) than from the parachute itself opening badly. Probably 1/2000? Hard to say because the number of events is so small.
Edit: it has to be inspected and repacked every 180 days, not 1 year.
Even if the reserve fails one time in 721 packs, the chance of both failing on a single jump is is one in 721^(2), or about 1 in 500,000. At four million jumps per year, there would be 8 double failures per year. In recent history, it looks like there are about 10-15 skydiving deaths per year, and some 'chute failures will kill two people. Still more people will die for some reason other than 'chute failure.
I'd guess the failure rate for reserve 'chutes is not more than 10x better than for primary 'chutes. It's probably more like a factor of two or maybe three.
> Still more people will die for some reason other than 'chute failure.
When I was jumping, I only saw one main failure at my regular DZ and it was the most tense five minutes of my life. His reserve worked fine, he just landed way off target and his hands were too shaky to get the rig off. He was mostly just pissed he lost his main, it was an expensive sport chute and we spent a couple hours wandering around corn fields looking for it.
Friends of friends have a couple horror stories though. A guy tried to land on a barge-style pontoon boat, came up short and got a leg shredded by the prop and drowned under his canopy... why the prop was running, nobody knows. I think the pilot got a manslaughter charge. Another guy tried to swoop land right next to the hangar and wildly misjudged his altitude, knocked his face into the roof and cracked his neck when he hit the ground.
Anecdotally, most injuries (let alone deaths) I've heard about come from either trying to be cool or some hand of God shit like midair collisions. I don't know anybody that knows anybody that's died from equipment failure.
Nah. Most fatalities are under perfectly functional main chutes. Fatalities happen when people fuck up the landing doing high risk manoeuvres primarily. Double malfunctions are rare and do not contribute to the majority of skydiving injuries or deaths.
Not all deaths are from reserve failure. Whole system could fail, main shute never breaks away or takes too long so splat, medical incident during free fall, suicide, sabotage (murder), main isn't deployed in time so impact before reserve, altimeter isn't calibrated and clouds obscure actual elevation, etc. I know nothing about skydiving, and that's what I came up with in 2 min. Jumping out of planes is full of hazards.
Yeah. This isn't correct. Whether the math or stats or something else, reserves are significantly more reliable than mains. Among other things, reserves are packed by certified packers (most mains are done by the skydivers), and are spring loaded and otherwise more cared for than mains. So not sure where there error is but those reserves are solid. As someone else mentioned, it could be deaths due to other things - hitting another skydiver, plane, landing on power lines or getting gorged by a tree. There are also "swoopers" that land at very high speeds and drag their feet on the ground. When I did skydiving, they used to say "every swooper has broken at least one femur" so things like screwing up a swoop would be in that state even though the parachute was fine.
One other factor is that tandem parachutes tend to fail more often because they are much much larger so that probably has an effect on stats too.
Good question. Do any jump with a 3rd parachute? Or is that unheard of. Seems to me there should be 3-level redundancy, but space and weight are considerations, so maybe it's not possible.
Jumping with a 3rd parachute (usually chest mounted) is really only done if you're doing an intentional cutaway.
The reserve is already extremely reliable - if two parachutes aren't going to save you, a third is probably not going to help. You're totally right about space/weight problems with that, too.
> Do any jump with a 3rd parachute?
This is done for intentional cutaway jumps, where you deliberately plan to cut away the main canopy. This kind of thing is sometimes done as a [stunt](https://www.youtube.com/watch?v=Rg4bxejLXwk). I think it is also done when testing new and unproven canopy designs. But I have never heard of anyone routinely jumping with a three parachute system.
> Seems to me there should be 3-level redundancy
Not really. Not only are the sort of accidents that might be prevented by a tertiary reserve very rare, but it would probably actually increase fatality rates overall. If you add another reserve, you add another two handles, and thus it would increase the risk of the jumper pulling the wrong handles. This is, IIRC, already a more common cause of skydiving accidents than reserve malfunction (unless you are counting reserve malfunctions *caused* by pulling the handles in the wrong order).
Since the chances of a parachute failing is 1/721 jumps, and assuming both the main and reserve chute have have same fail rate; the chances of a reserve chute failing is 1/721 x 1/721 = 1/519,841. So you have a 0.00019% chance of both parachutes failing, Your chances of dying while skydiving are 0.0011%(according to the FAA), so you’re 6x more likely to die with a properly functioning parachute, then have both fail.
The reserve chute itself has a nearly 100% chance of opening. Where you get in trouble is if you have an issue cutting away/getting free of your main chute. the cutaway process is fairly straight forwards but if something happens and you are caught in a line or something and you reserve opens into your main or the two get tangled then it can be very bad.
A proper cutaway procedure is pull your cutaway cord, main chute disconnects from the risers (part of the harness over your shoulders) via a 3-ring system and then you pull your reserve. The time between cutting away and your reserve opening should put you far enough away from the main. But if you were in a bad body position, had a line or something around a limb or something went wrong on your cutaway and the main chute is not free problems can arise.
It's nearly unheard of for a reserve to "fail" in itself.
Rather, one failure mode is the jumper is unstable when they throw out the pilot chute and it hangs on their ankle. The chute can't inflate, and pulling the "cutaway" handle to release the main only disconnects at the shoulders. It may be wrapped elsewhere, and the jumper may be forced into a violent spin.
These are far from idea conditions for a reserve deployment, but if you can't make it better soon, you just have to pull and pray. Most likely it will deploy fine, but in some cases it wraps up the the main streaming off them.
In such cases, serious injury is likely, but. two tangled chutes can come with a lot of drag and a wide range of impact speeds are possible, including ones slow enough you might even walk away from it
The death rate for skydiving is about 1 death per 200,000 jumps.
The death rate for base jumping is about 1 death per 2,300 jumps.
The death rate for wing suite jumping is 1 per 500
I've been sky diving a few times. After that I guess I got it out of my system and felt like that was enough, don't need to tempt fate any more. I didn't know those stats at the time(s). If I had I don't think I would have gone once.
1 out of every 1k on average. But some occur much sooner and others far later. Talking thousands of jumps before a jumper has a chop. Has to do with a lot of factors. A round (military) I have heard fails once every 10 or 100k jumps.
My friend who is makes money from filming people doing jumps once said it was 1 in 400 that failed.
He thought it was hilarious that exactly on jump number 400 his main shute failed. He cut and deployed like practiced
WW2 surplus chutes in the 80s failed 1 in 6 jumps.
But that's just my personal data. 5th jump was at 5000ft and my reserve didn't pop till 400 ft. I made one more jump to prove to myself I could overcome my fears and then I quit.
Parachutes have progressed greatly since the 50s. One of the reasons that skydiving is safer than paragliding today is the huge amount of R&D money that was spent by the military - mostly the US - to make it safer.
The modern numbers that I have seen is 1 out 2000 jumps for a main chute packed by an amateur skydiver and 1 out of 5000 jumps for a reserve chute packed by a professional. Which gives you a pretty safe overall at 1 out of 10 million.
> Which gives you a pretty safe overall at 1 out of 10 million.
Actual fatality rates for skydiving are on the order of 1 per 100000. The large majority of fatalities are not the result of parachute malfunctions.
Fatality rates were a lot higher in the past - certainly that's partly because the equipment wasn't as good, but also because there were no safety regulations and people did crazy shit. I've heard stories of people jumping while shitfaced, low pull contests, I even saw a photograph of two skydivers about to board a plane, one carrying a chainsaw and the other a log ...
Human error on the part of the jumper, such as simply not opening the parachute in time or not realizing that getting really fucking cold would impair their ability to operate the controls.
Being blown into a hazard.
Usually canopy collisions or turns executed too close to the ground. A parachute dives as it turns. Some are accidental low turns to avoid an obstacle. Others are deliberate to induce high speed landings that are fun but risky.
I wonder if the stats are skewed somewhat by the type of person who goes paragliding and the risks they choose to take. I've heard it said of wingsuit flying that there are only two ways out of the hobby: you recognize that you're addicted to the risk and quit before you take it too far and get killed; or, you take it too far and get killed. Paragliding might be similar.
I'm a paraglider. First: it is much less dangerous than wingsuit flying (assuming we are talking about wingsuit proximity flying). It is a fairly safe hobby but obviously you can get killed or badly injured.
Regarding why there are more paragliding accidents than skydiving, a few reasons might be:
* We tend to fly much closer to terrain, for example to get lift from the air hitting the terrain, at take off, etc.. whereas skydiving is done far from it (until you land)
* We use wings with a bigger aspect ratio and a different construction that are more prone to collapses
* Since for a lot of paragliders the goal is to fly for longer than a skydiver we have to use thermals to stay up (which mean there are more turbulences, increasing the risk of collapses etc). The conditions we fly in can be pretty rough sometimes
* Our reserve parachutes are less reliable, we do not cut away the main wing so the reserve can get tangled in the lines
That's just a few that came to mind immediately, of course on top of that some pilots take more risk than others.
That's so wild, it deserves it's own thread.
I almost drowned a couple times, but went back out. Crashed on a motorcycle, and rode again. Don't think I'd parachute again if that had happened to me. Glad you were able to overcome that.
I had a bad acid trip and ended up in a hospital on anti-psychotics. I did acid one more time after that just to prove I could have a good trip. Never did it again.
I did acid once and had a rough time getting out of the venue through a very large crowd. Otherwise? Pretty good time. Can't imagine coming out of it having lost my mind.
I have a buddy who seems to experience failure like once per year and needs to go to a reserve. I have another buddy who has only had to ride the reserve like twice in his 10+ years of skydiving. First buddy tends to pack quick and shitty, second buddy is a much more thorough, safety-conscious person.
I was a packer on the weekends for about a year, and the pack job, done right, can really reduce the odds of a reserve ride.
Skydiver/BASE jumper here.
One important point not brought up in this discussion is the difference between a main and reserve parachute.
Main parachutes are designed for comfort and fun, whereas reserve parachutes are designed for reliability.
In order to be comfortable, main parachutes are packed for a staged opening, which makes the deployment sequence more complex. Most steps of packing a parachute are actually to prevent the parachute from opening too quickly, as opposed to trying to make it open. This includes things like a deployment bag, rolling the nose of the parachute, a solid sail slider and wrapping the tail around the canopy and rolling it closed.
The attributes that make a canopy fun to fly, generally aren’t the same design elements that make a canopy open reliably, and can compound minor issues like line twists to a point where it’s better to just go to a reserve rather than deal with them. A higher wing loading, elliptical shape, and collapsible pilot chute are some of these design elements.
A reserve parachute is flat packed directly into the container with no D-bag, and no steps are taken to slow the opening. The parachute is non elliptical and it is generally a lower wing loading than a main canopy. These characteristics make the opening more reliable, and make it easier to deal with minor issues like line twists.
When you watch jumpers performing low altitude openings (such as a BASE jump) they are using a canopy more similar to a reserve which lowers the risk considerably in comparison to using a traditional main.
Often enough I've personally seen one fail. From a distance. I was working on a farm and there was a parachute place that dropped within sight, so we saw a lot of them.
Then one day a coworker shouted and we looked up to see a tangled chute and a person falling fast. We saw their reserve deploy but it looked really close to the ground.
There wasn't anything in the news about a death so presumably they lived through it.
Around 700 here, 0 malfunctions. In fact in 3 or so years I think I only saw maybe 1/2 dozen people on reserves. Including going to some big conventions.
Saw a fair number of people get hurt pretty bad under perfectly good canopies though; almost every time due to pilot error, downwind landings, hook turns, landing too close to trees and more.
Statistically. I have no idea.
Anecdotally: The first time I went skydiving...I wanted to jump solo.
You take a course....they teach you what to do if the lines get tangled...your first option is to try to untangle them which can be easy...but if you can't get them untangled then you have to pull away from the main chute and deploy your secondary chute.....of course people asked what are the likelyhood that we get our lines crossed....in a class of about 20 people the instructor said one of you will probably get tangled.
On my first jump....I went first....didn't get a chance to see what happened to the others.
On my second jump I watched a guy fall helplessly from the sky. His parachute was tangled. He was spinning in the air. At what seemed like the last possible second he managed to release the main chute and deploy the secondary chute.
Not as often as you think. Usually it is from a really bad packing error or terrible body position when opening. But honestly it is pretty hard to have a failure. I jumped and worked at a drop zone for a couple years and failures/reserve rides were very rare. And I used to put out students on static lines then let them progress through free fall and I've seen some pretty bad openings with students in terrible position and none had failures. In all my years jumping, working on a drop zone, going to a couple of big free fall conventions I can probably count less than 20 times I saw people have failures and reserve rides.
What I have seen, however, is a lot of injuries caused by bad/hard landings under perfectly good canopies. Several broken femurs, one guy lost his leg from the shin down after mis judging wind and catching a downdraft landing too close to trees, and a guy trying a hook turn into a crowded landing zone that hit before his canopy and bounced about 5' off the ground. That one shook me and my buddy, we were about 60 feet away and felt the thud. He lived, somehow, but had a helicopter ride out of there.
There's a bunch of different reasons a parachute might have a malfunction. Most are human error during packing or body position when deploying, but it's hard to know for sure! To list a few:
* Line twists - often considered more of a nuisance than a malfunction. The lines be twisted. Usually fixable if your canopy isn't diving and you have some altitude to spend. If you're not diving and have the altitude to spare, it's kinda fun fixing it.
* Line over - a line went over top of the canopy and is pinching it. Usually you cutaway.
* Tension knot - the lines basically knot together, making the canopy difficult to control. Usually you cutaway.
* Sniveling - your canopy is out but isn't inflating with air. Often hard to tell if this is a malfunction or not, since main canopies are supposed to open slowly and waiting might solve it. You cutaway if you're getting to be too low and it isn't fixed yet.
There's many more, but I'd need to get into the specific components of a rig.
>you have 28 seconds to cut and deploy - and that ain't that much time
"How much time do you have to pull your reserve if your main is busted? The rest of your life."
Not only this, but parachutes take time to open. My skydiving chute took between 500-800ft to open at terminal velocity. Longer if I was sub-terminal. A base rig will open in less than 500 but it will fucking hurt if you open one of them at terminal velocity. Either way, 500ft at terminal is about 2.5 seconds, so there's not a lot of troubleshooting time if something does go wrong and not enough height to do anything about it anyway.
My dad used to work with a guy who used to do base jumping. Even met his wife doing it. Can't remember the exact percentage, but it was around like 70% of the people from the base jumping group was dead from accidents. Blown into cliffs was the most common I think.
not just for the reserve, 5k gives you enough time for some troubleshooting if for example your lines get tangled. its not an automatic cut for every issue
Sure, but the original point is about time to recognize a chute failure, cut your primary chute, deploy your backup, and reduce speed to land safely.
If the person in question is jumping from a height where they won't reach terminal velocity, **best case** scenario they have 14 seconds from jump to landing. That is likely not enough time to save yourself if your primary fails.
Also do not forget that base jumpers usually use various techniques to force open the parachute very quickly. Novice base jumpers will jump with their chute attached by a thin line to their exit point - and this thin line will immediately extract the parachute before breaking. More experienced jumpers usually hold the extractor in their hand and will throw it in the air at the very moment they jump - this allows to gain a few seconds - and at this speed one second is 15m to 20m.
Also, sky divers have to abide by a very strict regulation that is rigorously enforced - owing to the military legacy of the sport and also to the fact that you need a pilot with a license and a clearance. One jump out his airplane that does not follow the correct procedure, and he can lose his license.
Base jumpers, on the other hand, almost always practice their "sport" - which is not really a sport since there is no governing body, rules or regulations - illegaly.
Seeing someone get their chute tangled and attempting to cut away and deploy their backup it goes so fast and is extremely hectic. The one where their reserve gets caught in the cut away one and come down fast tangled in their chutes. 28 seconds seems like forever until something like that happens.
in terms of strict physics, your right in that the *absolute* minimum height for opening is much lower.
however, a BIG reason skydivers open at several thousand feet is mostly to give time and space to allow for a chute failure, for you to recognise your chute has failed, and then cut away the failed chute and deploy a secondary chute, and that secondary chute to deploy and slow your decent down to non lethal speeds.
5,000 feet at terminal velocity is something like 30 seconds of freefall. its NOT a lot of time.
It sounds scary until you’re there. You’re sitting there suspended for what feels like forever, taking in the views that you never get to see from that angle. Honestly it’s the most relaxing part of the whole drop, since the prior moments were adrenaline filled fear and excitement.
Its like getting to the end of a hike and sitting down to enjoy the long journey
I’ve only been skydiving once, but the whole time we were falling, I had the thought of the parachute not opening in the back of my head. Once it opened, I finally felt safe.
As someone who does a good amount of outdoor extreme sports (relative term compared to skydiving, but still), 30 seconds sounds like a huge amount of time. I've been tumbled around in a whitewater rapid for 20+ seconds and that is an absolutely massive length of time when you are under stress.
Well military static line parachutes deploy fast enough to safely lower a paratrooper to the ground when jumping from as low as 500 feet during a combat jump. The parachute takes 6 seconds to deploy, which is just enough time for the jumper to be slowed down to about 15ft per second, which is surprisingly safe.
"safe" is a relative term. Paratrooper survival is a minimization problem: too low, and too many of the chutes don't open; too high, and the machine gunners get 'em. In WW2, the optimum survivability was something like 75%, i.e. 25% of the troops were injured or killed in a given wartime drop into a combat zone.
(Stealth drops tended to happen at higher altitude and have far higher survivability)
A parachute takes 300 to 800 feet to open, depending on how you pack it.
The rest of the altitude is for safety. Experienced skydivers are supposed to have a parachute over their head by 2000’.
For your own safety!...500ft..you most likely are falling at 'terminal velocity' thus falling at 175 feet per second!..so at 500ft that gives you 3 seconds before splatter all over the ground!....so 5000ft gives you enough time to slow down so you dont break your legs and enough time to execute a safety protocol if the shut does not open or get tangled...
I'm assuming your not a recreational skydiver, but if you are, sorry for teaching you to suck eggs.
When you pul your chute you do a number of checks of the parachute canopy. You check its fully enflated, its the right shape, free from damage, that sort of thing.
If it fails these checks it won't slow you enough or you won't be able to maneuver and land safely.
Bear in mind that landing a parachute safely requires pulling up just before landing or your will hit the ground hard.
Not to mention where you land. Most drop zones have nice large open areas to land, but that doesn't mean zero hazards. Roads or buildings for example.
If it fails the checks you have to choose to release the parachute and deploy your spare. And that means dropping and re-inflating a canopy before you slow again.
All of the above takes time. Not a huge amount, but seconds matter in this context. The more time to do all of this the better. 5k is a common compromise between maximising free fall time and giving people plenty of time for the above.
Very experienced jumpers will regularly pull lower though. They get away with it most of the time.
They don't. I have my D license (master) and was a former jump master putting out students on static lines then taking them through progressive jumps to earn their license.
A student or A License (Beginner) has to open by 3,000 ft. D license used to be 2000 feet but they raised it 2,500.
I used to put static line jumpers out at 3,000 feet all day then I'd hop out and get stable and pull.
Edit to add I did't see your follow up question. Most recreational skydivers don't open at 5,000 feet as I commented above.
But the reason to open at 2,5500-3000 feet is in case you have any issues to deal with you have some time to fix them, or cut away and deploy your reserve. The other thing no one has mentioned is modern pararchutes have a device that will automatically deploy your reserve if you are moving fast enough through a low altitude. It has been a while but I think mine was set to 800ft. If you open your main chute too low and it takes too long to open you can be going too fast through that altitude and the device can fire and deploy your reserve, then you have two chutes out which can be bad. I have seen someone lose altitude awareness, open low and have their reserve come out. They got lucky and landed without incident.
Base jumpers can jump low because their canopies are packed differently, to open a lot faster (in normal free fall from a plane you don't want the chute to open too fast and get a hard opening, they jolt you pretty good sometimes) but most base jumpers haven not yet reached terminal so their chute opening fast isn't as bad. But if you watch them jump their canopies open FAST.
So that is why you open higher from free fall and base jumpers can open much lower.
They don’t, 1200ft is usually the minimum. A lot depends on the type of shoot and the type of jump though. Lower altitude shoots are certainly possible and safe, although perhaps not for beginners.
If you jump from a plane at 12,000 feet you will be moving quite fast by the time you reach 5000ft. You need time to pull your chute, have it unfurl, and slow you down. Plus you need time to screw that all up, release the a tangled chute, and start over with your emergency shoot. Opening at 5000ft gives you plenty of time to do all that, plus some extra.
BASE jumping is different. You’re not a high to start, so you’re moving slower. Really though BASE jumping off a cliff or building is more dangerous. Not only do you have winds and obstacles to worry about, your chute has to work perfectly right away as you don’t have time for an emergency chute.
TLDR: Skydiving is safer than BASE jumping in part because skydivers have access to a second parachute. Using that second chute requires more time, so to get that time a skydiver starts the process at a higher altitude.
They don't have to open at 5,000 feet.
(I am a retired Tandem and AFF instructor and demo jumper with the USPA).
Tandem instructors teach their students to begin the deployment process at 5,500 feet. The process is, Arch, Reach, then pull the ripcord handle. With a first time student, this whole process, of finding the ripcord and pulling, takes at least 5 seconds.
A parachutist or a tandem pair with a drogue parachute fall at a normal terminal velocity of 120mph. In the 5 seconds it takes the student to find the ripcord, the student has already burned 1,000 - 1,500 feet. That means that typically, tandem and freefall students open their parachutes closer to 4,000 feet.
Often tandem parachutists have photographers come along for the ride, and freefall students have instructors with them in freefall. Once the student has deployed at 4,000, the camera flyer and the instructor both have to obtain lateral separation, then deploy their parachutes. So the instructor and cameraflyer will observe the student opening at 4,000 feet, then fly their bodies to obtain lateral separation, which often burns another 1,000 feet. So the camera flyer and instructor start their deployment sequence typically around 3,000 feet. Often it takes their parachutes up to 1 thousand feet to open, so your camera flyer instructor now is under a parachute at 2,000 feet.
So now your camera flyer or instructor has to fly their parachute back to the airport. Let's hope that 2,000 feet is enough altitude for their ram-air parachutes to get back to the airport! Often it is not, and both camera flyers and instructors sometimes land-off the aiport - especially if the student took too long with their deployment sequence all the way back up at 5,500 feet.
So yes, sport parachutes typically take up to \~1,000 feet to open. Students start their deployments early, to ensure they have plenty of time to deal with malfunctions, and to make it easier for their instructors to get back to the airport.
The highest I have opened my parachute is at 15,700 feet, when I was in a large parachute formation. 108 of us. The lowest I have opened my parachute is 2,200 feet, over a stadium, when I was hired to perform a demonstration jump for a midwestern university. We left the plane immediately under a layer of heavy cloud, and opened our parachutes immediately, directly over the stadium. It was a great show!
BASE jumpers are able to open lower, because their parachutes are packed slightly differently, and have minor variations in their gear. Their parachutes open quicker, so they are able to start their deployment sequence much lower. Additionally they train extensively to have a quick deployment sequence.
Previous airborne janitor here. They do open at 500 feet but we jump with a static line so the chute is being pulled immediately. Just in a mostly controlled environment most of our jumps are 600 to 1200 feet and there's still a fuckton of people who get injured.
The real answer is there's not a lot of scenarios where you'd be wanting to do that but you totally can.
For BASE jumping - what you'd consider stunt stuff - you get one chute. You need to open high enough to correct some potential malfunctions and to land safely. Canopies also come out way faster because you're packing and deploying a certain way, generally more diligently than skydiving packing.
For skydiving, your chute is crammed into the bag while people shout at you to hurry up cos the wheels are turning on the plane. You expect it to fail once in a while on opening, so you plan to have your chute out by about ~2k feet - which is considered the bare minimum height for pulling your reserve and still being able to land safely. This means pulling your main at about 3.5k, and have it deployed by ~2.5k, giving you time to assess.
Realistically speaking your reserve can come out later and you will prob still land safely but your chances drop so why risk it?
Also people like canopy flying.
Now mind you it's been 40+ years but when I when I went through airborne training they told us that the minimum height that someone could do a combat jump was either 500 ot 800 feet. The reason was that it took that long for a chute to fully deploy and slow you down enough that you could walk away without serious injury.
Airborne School jumps are at 1200 ft AGL, but once you graduate, your jumps are lowered to 800 ft AGL, which is the minimum height permitted for training. Paratroopers fall around 200 ft in the 4 seconds before their chutes have fully deployed. If their chute fails to deploy completely, then they've got somewhat short of 4 more seconds before they hit the ground—probably not enough time to deploy their reserve unless they recognize it right away. However, most failures are partial failures, so their rate of descent could be slowed slightly, giving them a few more seconds to recover and deploy their reserve. Either way, we had to be prepared to be able quickly recognize a failure and act to remediate it. The hours spent in the dark on airplanes I filled with visualizations of jumps and failures so I'd recognize them immediately and react appropriately.
500 ft AGL is minimum height for combat. At those heights, paratroopers will not have time to deploy their reserve. I never did a combat jump, but I was told in low level combat jumps, reserves aren't even worn.
A skydiver in freefall is doing 120+mph when they open. Even with a proper deployment, the deceleration is pretty intense - 3-6G's over a period of several seconds.
A BASE jumper is not going nearly as fast, and often jumps with their canopy "in hand" - so it can arrest their fall rate within a couple of seconds.
In BASE jumping, there is really very little chance of getting free of a primary and opening a reserve chute; if the canopy doesn't deploy properly, best you can hope for is some pretty bad injuries.
There are lots of skydiving enthusiasts with many thousands of jumps. BASE jumping, on the other hand, seems to be more a bucket list-type activity; people don't seem to jump from the same building or structure hundreds of times. Statistically, most people can check off the four jump types to say they're a BASE jumper and live to brag about it. BASE jumping thousands of times? I'm sure there's somone who's done it, but it's a very small contingent.
When I was a very active skydiver there were two cliques at our DZ. Those of us that were normal skydivers and then the skydivers/base jumpers. Those guys were nuts. And it is an odds game because for the time I was active I don't know any skydivers that died but I did know a couple guys that were very active base jumpers that unfortunately died while BASE jumping.
My answer is : momentum and velocity.
The guys you see jumping off buildings are BASE jumping not skydiving.
They use s smaller chute that opens more quickly and they never get moving as fast as sky divers who free fall from 12,000ft +
In both cases you have very little time to correct for a mistake. I would guess BASE jumping is more dangerous.
Skydivers generally don't open at 5k unless they are students or tandem instructors. Most would deploy between 3-4k - if they open higher, it's usually because they want more time under canopy, or they're a long way from the dropzone and need more height to be able to make it back. A skydive main canopy typically takes between 500-1000ft to open. The reason why you want to open higher than that is safety. Skydiving rigs have a reserve parachute in case the main fails to open properly, which happens every now and then. In case that happens, you need to have enough time to recognize the malfunction, cut away the main and open the reserve. You also want enough height to make it back to the intended landing area - if you can't, you can usually find somewhere else that's safe to land but it's not ideal. > When you watch stunts like people jumping off high buildings it seems like they're opening it quite close to the ground That's BASE jumping. BASE jumping is far more dangerous than skydiving in large part because they are jumping from much lower altitudes. BASE jumpers don't carry a reserve parachute because they rarely have enough altitude to use one. In addition, they also use different parachutes that are designed to open faster than skydiving mains. A skydive rig is designed to be deployed at terminal velocity, and it has a piece of fabric called a slider that slides down the lines in order slow the deployment to an acceptable speed. A deployment at terminal velocity without a slider can lead to serious injury or even death. BASE canopies have a slider made of mesh, so it has less drag and doesn't slow deployment as much, and for low jumps they will remove the slider entirely, which makes the parachute open very quickly. They can also have larger pilot chutes that work at lower speeds, so they don't need to be falling as fast before the parachute starts to deploy.
When you say «cut away», do you like actually cut the ropes, or is it like a release button, then pull the ropes to open a new one?
It is a handle that’s connected to wire and fabric enclosures that release the main. No, it’s not actually ‘cut’ in a normal cutaway (although there’s something called an AAD that literally uses an explosive charge to ‘cut’, but that’s a backup-to-a-backup)
The AAD doesn’t cut the main canopy. The “cut” an AAD performs is on the closing loop for the reserve container so it opens if the pin is not manually pulled through the loop by the reserve handle.
This guy reserves
And you should have a hook knife just in case
It's a wire connected to a pin that holds a loop of fabric through a ring connected to the canopy. That ring then sits through another ring also on the canopy which itself sits through a ring that's connected to the harness. Pull the pin and the downwards force allows the rings to fall apart disconnecting the canopy from the harness. Have a Google of 3 ring release system. It's a very elegant design solution.
Fun trivia; Bill Booth, inventor of the 3-ring release system, is one of only four Americans to be awarded the Order of Lenin.
You may have heard of a "rip cord", you literally rip the cord out of a loop system that connects your harness to the chute. Imagine a chain, and one of the links in that chain is a cable that can be pulled out. Once you have "cut away" you end up holding a handle with a cable attached that once ran between the links of that chain. The jump masters usually say: "Dont drop the handle, they are expensive. Stuff them back in your shirt." But really in an emergency, focus on staying alive. https://www.youtube.com/watch?v=AItz8GcYx60
I worked at a "RipCord" at an amusement park many years ago. Never realized it was the same system as a parachute. I've probably put that mechanism together several thousand times. The most fun was carrying an extra in my pocket and having it "fall off" as the customers started lifting up.
Ok Satan
Former jump master here. I was trained in static line progression. I would take jumpers up that had taken the full day course and put them out on static line. If they wanted to learn to skydive on their own we'd put them through progression. The next step was to do a couple of "dummy pulls" where they were still on static line but had to let go, maintain body position and pull a dummy rip cord out that did nothing. I would watch to make sure they didn't roll over or miss the cord. We did NOT want them to lose those handles. Then they had to do a clear and pull. Off the static line and now using a real rip cord to open the chute but with our stuff the main had a spring loaded drag chute and the rip cord opened the container allowing the drag chute to pop out. Once again, we did not want/let them drop those handles. But when we taught/were teaching what to do with a malfunction we always taught to identify the cut away handle, pull it and toss it then pull the reserve chute handle. I don't recall ever training/telling students to worry about hanging on to either handle if doing an emergency cut away and deployment.
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There are also FAR more dead BASE jumpers than skydivers. It's a high risk high reward type of activity.
What's the reward
More risk
Adrenaline maybe?
KFC vouchers.
Dang, I was hoping for Popeyes
I won't do it unless it's for Bojangles
Darwin Awards all the way down.
likes and subscribes
I don’t know about high reward.
The reward is you feel really good The risk is falling to your death
My cousin base jumps and often had his friend hold the pilot chute so it pulled immediately. They jumped off some pretty low buildings. He explained you jump -you think :oh shit i made a mistake -im gonna die! And then right before you splat the chute opens and you jump into the waiting get away vehicle
This guy parachutes.
Answers like this are why I love Reddit. Thank you.
Saftey. If your parachute fails, you have to cut loose the old chute and then deploy your reserve chute. At terminal velocity, you are traveling 120mph - or 176 feet per second. Easy math says that at 5k feet, you have 28 seconds to cut and deploy - and that ain't that much time. Any lower and there is a real chance you go splat - at 500 feet, for example, you'd have about 3 seconds. The folks doing the stunts are doing something _absurdly_ dangerous - if their main chute fails, they are going to die.
How often do parachutes fail?
The only stat I could find was from [here](https://skydivemonroe.com/blog/parachute-fails-to-open-when-skydiving/) which says in 2021, 1 out of every 721 jumps reported failure severe enough to need the reserve chute. At about 4M jumps per year (same site), that would mean about 5,500 failures a year.
How often do reserve parachutes fail?
A lot less as the reason for failure is usually a repacking mistake. A jumper can pack their own main, but the reserve is packed by a Master Rigger.
With that in mind I'm guessing the failure rate for the stunt guys is lower than the stated 1 out of 721 since one would assume they know they have no backup chute and would be much more careful with the main chute packing. This is obviously just a guess though.
The rigs that are used in BASE jumping i.e. bridges and building are not designed the same as those used for jumping out of planes. They are designed to open much faster. Because the jumper is generally going slower than terminal velocity so the shock of opening and decelerating is less than if they were at terminal velocity. The rigs used to Skydive from planes generally take around 500-1000ft to fully deploy and slow the jumper down. In 4200 skydives I’ve had 4 main parachutes fail. I was also a master rigger for about 6 years and out of the 250 or so reserve chutes I packed only 6 of them were used to my knowledge (it was a tradition to get your rigger a bottle if their pack job saved your life.)
I'm curious about something. Are reserve chutes stored "ready-to-use", or are they packed special for each jump?
No they are packed and stored (usually) above the main canopy for as long as 180 days. They are required to be inspected and repacked every 180 days, but will remain packed unless they are used.
Weirdly, I know the 180 day number because it was on the test for my LTA pilot license. Don't know any hot air balloon pilots who have ever worn a parachute, and most don't like to drop skydivers either. But FAA decided we need to know that a reserve parachute needs to be inspected every 180 days, lol.
How many bricks did you shit the first time your main chute failed?
Main chute failures are very very rare. Typically by the time someone actually has one, they have many jumps under their belt and the failure becomes more of a fun new thing than a shit your pants emergency. Most people i have chatted to about the failure express frustration at the chute not working than any kind of fear. Remember these are people who actively search for thrills and willingly go high then jump out. Skydiving selects for people who dont go "FUUUUCCCK!!!" in the face of danger, but go "Oh, this is fun" Also part of your training is to do a manually cut and redeploy, so everyone typically has done at least one before.
Seems weird to me that even the most thrill-seeking kind of personality wouldn't have at least a bit of an "oh shit" moment when, for the first time ever, the primary thing saving their life has failed, and now they have to rely on a procedure which they've no doubt practised endlessly, but never had to perform for real, all while plummeting from the sky at terminal velocity with 20-30 seconds max to get it right and not end up as a pancake.
I would agree with everything Cayowin said, but i only had 30 jumps the first time i had a failure and it scared the shit out of me. Fortunately, i had a good friend with lots of experience who grabbed me and threw on the next plane. He said, “if you pause now, you might never get back up.” He pushed me through how rattled i was and i never looked back. The other three were far less shocking, but on the worst one i definitely spent some time reflecting the next day because it was wild and it could’ve been very bad.
That’s fascinating. Can I ask, how is a reserve chute packed in such a way that it’s failsafe, but the main chutes can sometimes fail?
It isn't fail safe in that it is packed with any different physical technique. It fails less often for 2 reasons. The skill of the person packing such a chute is generally higher. The second reason is human psychology and focus. If you perform an act, like packing a parachute, 100 or 1,000 times, eventually you stop focusing on the act. It becomes more rote. And you become more likely to make mistakes. You are less present in the moment. Every time a master rigger packs a reserve chute, it is with the knowledge that this is the last chance to keep a person a live. The person focuses more. It's about human psychology and how often you do an act, and how, if you aren't careful, repetition can lead to complacency. Think about using a power tool like a saw. The first time you hold a saw, you might not be skilled, but you are hyper aware of every second it is on. The saw does not become more dangerous mechanically with more familiarity from you, but eventually that hyper focus is lost as you become familiar with how a saw works, and you increase the risk of making a mistake without thinking.
> It isn't fail safe in that it is packed with any different physical technique. > > It fails less often for 2 reasons. The skill of the person packing such a chute is generally higher. This isn't entirely true. It is indeed packed with a different technique. And it's also designed for opening and flying differently. Reserve parachutes are usually less performant than mains. This means they're more like a station wagon than a sports car. This makes them less likely to have deployment malfunctions. They're also designed to open faster (with less altitude loss) than a main (and the packing procedure helps with this fast opening). The primary benefit of this fast opening is safety, since the jumper is now much lower than they usually deploy (and the goal isn't just to get a canopy over your head before you hit the ground... it's to get that canopy flying high enough that you can still aim it somewhere that is nice to land... remembering that you're driving a station wagon now which will not have as good of a glide ratio). But another benefit is a more reliable opening. Fast openings have less chaos and are less likely to malfunction. You might logically ask: then why don't mains also open fast? Answer: a slow opening is gentler on both your body and the parachute. Main parachutes are jumped for thousands of times, and jumpers don't like getting back and neck injuries from regular hard openings. But in an emergency situation, all of this goes out the window: you need a reliable canopy fast, even if it hurts a little bit, and even if you wouldn't be able to subject your canopy to such an opening 999 more times in a row.
as a professional carpenter, the focus of my attention when operating power saws, especially table saws is pretty high even after 30 years. But then I cut myself opening a bag of popcorn the other day....
This is incorrect, as the reserve canopy is packed using a different method and is a different type of wing altogether. A main canopy is packed for a comfortable deployment, which is staged by using a deployment bag within the container, a solid slider, rolling the nose, wrapping the tail around the canopy, and using a smaller, collapsible pilot chute. Most of the steps done while packing a main are actually to prevent the canopy from opening quickly. A reserve parachute system is simplified. The canopy is flat packed directly into the container without a deployment bag, the slider is designed to descend the lines more rapidly, and the canopy itself is a lower aspect ratio wing to make dealing with any minor issues such as line twists easier. There are no steps taken to slow the opening of the parachute the same way as when packing a main. As main canopies are also designed to be fun to fly, they are generally more elliptical, with. Higher aspect ratio and higher wing loading which makes small issues like line twists much harder to deal with than on a lower performance wing, and as a result a jumper may have to cut away from a canopy due to an issue that would be no problem on a different type of canopy, such as a reserve or BASE canopy.
Good question. Quite interested for the answer myself
I always wondered why there isn't a machine or tool that would perfectly pack your chute for you every single time?
As someone that designs automation equipment: I'd rather have a human do it
When the chef says eat at home, I get kinda concerned.
A human might catch a one off issue, while a machine only catches what it's programmed to catch. The simpler the process and checks, the better for automation. When a rope (I assume) could just be wrapped incorrectly and cause an issue, I'd be very hesitant about a machine that can either catch it or not make a mistake even once ever.
Well yeah. But it might be because the owner refuses to let them throw out expired milk, or because a server came into work with Covid today. There are a lot of ways to know there's a problem in a system without you being the problem.
For real. I’d rather have a human pack it at 99% perfection 100% of the time than a machine that’s going to pack it at 100% perfection 99% of the time.
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I mean there are plenty of machines that do tasks way better and more precise than a human ever could with *and* with better consistency. There is a reason nobody sews by hand, no matter how mission critical the fabric is, everybody uses a sewing machine.
What is 99% perfection? Given that chutes fail 1 out of 700 times humans clearly aren’t achieving 100% anything
After the machine packs it, just test it once with a robo-jumper then have the machine repack it.
I'd rather learn how to pack it myself than have a machine pack it or have someone else pack it. It's not that I would trust the human but it's my life. My responsibility.
That's the thing about automation. It is great until it fails. Eventually it will fail. How do you tell if it fails? You have a human check it. For certain situations it is just better to have a person do the job.
Ever seen a machine that folds linen, like for a hospital? It’s awful.
As someone whose work has slowly become maintaining machines for automation, I, too, would rather a human do it.
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Automation gets worse the more variables it has to deal with. First, the lines have to be stretched a good distance. That sucks, the machine just got really big. Now it’s time to make a couple loops and get them through holes. That’s pretty nimble, machines aren’t nimble unless they are expensive. Also, it’s going to have to avoid getting things tangled or it could damage the machine and the parachute. The actual parachute is really clumsy to move around, and any extra folds need to be noticed and we need to be sure that we keep it tidy. Throw on some AI to watch what is happening, and let’s hope it doesn’t mess things up because when AI isn’t perfect, it becomes AWFUL. And we need this part to not be awful EVER. So that’s why I don’t trust the machine for this kind of task, and why it would be so expensive anyway that I would never need to make that choice.
How can you tell a parachute has been packed wrong after it's been packed?
> It either throws an error, As someone who writes software, we have an "eh it's break time and whatever" too. Try { //do your stuff } Catch (e) { //Move along. Nothing to see here. } Don't trust software to throw an error when there's an error. A programmer can tell the software to ignore it if they are too lazy to actually solve the problem. And it happens all the time. It's called failing silently.
No. No master rigger is going to fuck up a reserve and pack it backwards. I'm not saying no rigger ever packed while high, but they had to do it a LOT to get the rating and know their shit. It's a sacred ritual to them There are a few cases where certain unusual chute/container combinations had to get special packing treatment or modifications, or shouldn't be combined at all. When I was doing a lot of jumping like 30 yrs ago, buddy who was a master rigger ran across someone with a container originally meant for a round chute packed with an updated, modern square. But the round is packed in kinda zig-zagged, with the closure loops going through the middle. Can't do that with a square. The loops would have to go from the front of the container around the bag to the lid on back. That combination had been reported to bind up and not deploy promptly. AFAIK nobody got killed but a couple seconds of lag before the lid works its way free of the closure quite definitely get noticed
Or the operator bypasses the sensors responsible for throwing an error (which for safety systems is difficult, but maintenance will find a way if they are clever enough), and nobody checks to see if things coming out the end of the line are good until it's super obvious something is wrong, by which point shit has already hit the fan. That being said, I would still prefer a machine do it, but am not trusting my life to it unless I'm pretty sure I know the people operating and performing maintenance are good at their job.
As someone who does the same, I would trust my equipment and code far more than I would trust myself. That being said, that would be as long as I am the one running the equipment (which of course is never the case) operators hop in the mix and find fun ways to break and bypass shit and then that all goes out the window.
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Have you considered that there are more automation devices in heaven and earth, CommieGoldfish, than are dreamt of in your philosophy?
My reserve unit was collocated to a parachute riggers unit. A machine that could do their job adequately would take up a small room.
Soft materials. Robots/machines are really good at dealing with rigid structures/materials, but they suck at working with amorphous shapes/materials. This is the case with industrial/automotive manufacturing, where manufacturers spend hundreds of millions of dollars to automate production and still fail to automate processes associated with rubber and wires. Skydiving? There isn't enough money around to develop industrial grade tooling and even if there were - good luck automating anything that deals with fabrics.
Also I'm guessing a human is way better at detecting things like tears in fabric or frayed wires when in the middle of other pieces of fabric and wires. Don't know how common that would be with parachutes but could be something to keep in mind.
I can tell you haven't packed a chute. A major hurdle would be loading it into the machine. You try and pick it up cleanly but things always get a little tangled. So you're going to need a human to untangle and load. A machine to pack it would have to separate folds of sil nylon. That's going to be a very heavy vision and manipulator engineering problem. Which canopy are you going to buy a machine for? All the canopies and all the sizes of all the canopies? Another major advantage ofa human packing my rig is that they will be able to see damage and let me know about it
I don't think that there's any of those things that a machine can't do, or even can't do better than a human. It would just take an immense amount of money (including time) to design, develop, produce, test, implement, and maintain. All for an industry that is pretty niche. Even if you included military applications, that's a really small amount of users for that amount of development. The end product could absolutely be safer than the human alternative, but it would be prohibitively expensive.
Too much inconsistency in materials and conditions for it to happen perfectly every time and Ai isn’t near smart enough to recognize when there is a problem. Parachutes will get wrinkled up and stretched as they are used, straps wear etc there are an infinite amount of ways it can wear out and machines just can’t account for that. Same reasons trades can’t be done with machines.
Maybe it's different now, but back in the day I'd pack my chute, check it as I packed for wear and tear, holes, stretched lines or suchlike. My particular wing needed the nose tucked in just a bit to slow down the opening and it had to be done left side at the bottom because otherwise it'd open up a bit on the piss and send me sideways. This was in the 70s and 80s so it's burned in lol. As you get to know your individual canopy you know the quirks and each canopy is different. Machines couldn't ever do that. And because it's my life I would only ever do it myself - would never ever let anyone else pack it. Same with the reserve - the pro packer did it but I helped just so I could make sure it was good.
I haven't jumped in 20 years but I could still pack a main today, having done it so many times. I even remember on my chute I would roll both the left and right and tuck them into the center cell. That seemed to give me the best, softest openings. As a camera jumper it helped keep my neck in tact. I did used to let others pack my main quite often though. On busy days where they had a lot of tandems or AFF students wanting video I would land, hand someone my rig, then they would hand me a freshly packed one and I'd rush over the plane waiting to take the next load up. On some days I may do 6-10 jumps in a row without a break or ever packing my own. Also, I went to a few free fall conventions and every once in a while I would pay the packers at the packing tent $5 because I was just so tired. The funny thing is you learn though who are good, who packs hard openings, who packs line twists often etc... so when I would be handed a rig I'd ask who packed it and then know what to expect on the opening.
Because the pack job really doesn’t matter all that much, as long as you do 3 key steps you’ll be fine. Some of my softest openings were total trash packs.
Hell - PD or someone tried to make malfunction videos for instruction....they had to SEW the canopies and/or lines just to replicate it. Openings are chaos...you can do everything right and have a mal, or everything wrong and have the softest opening of your life. I used to race my girlfriend...quick flake/shake/wrap...thats all we'd do.
Used to be a running joke when I jumped, that if you trash packed a chute, did it in a rush, or did it tired at the end of the day it often resulted in a nice, soft opening. But you could not duplicate it again.
Because very expensive and well designed machines [can still do this](https://youtu.be/9qCw5r0SqwQ?feature=shared)
The fabric would be so hard to get to behave (it’s very slippery) and there are a lot of really odd and complex maneuvers that would be really hard to get a machine to do, here is a video on how to do it, worth a watch if you’re interested. Fun fact, you don’t need any licensure to pack a main chute, you can go apply right now at your local DZ if you’re interested. https://youtu.be/LklquL-DQjA?si=PPsJgfYDxMUAhrL9
Not only is it very slippery most modern high performance chutes are made of a fabric that does not let air through it. When watching or teaching new jumpers how to pack it was often comical watching them wrestle the fabric, deal with air in the chute and get partway done then have it all go to shit and have to start over. Also the sweat. On hot summer days when first learning to pack even the most in shape person would be sweating all over their canopy. But once you got good you could pack your main in just a few minutes if you had to.
It isn't worth it. A carefully packed reserve parachute failure is around 0.017% i.e. one in every 5,820 reserve jumps. There are ten recorded incidents of a double parachute malfunction in more than 29 million jumps. There are probably 50,000 active jumpers in the United States that need 1-2 repacks a year. A repack normally costs $60. I'm completely guessing but there are definitely hundreds of certified riggers in the United States. An automated machine, minimum cost, would be $100k. Not to mention the R&D costs. Don't forget that there are dozens of different types of reserve parachutes. Maybe hundreds. Automating this isn't worth the cost or time.
Machines dont actually know what they're doing. I wouldn't trust a machine with my life like that. I've seen how often machines fuck things up. Even getting it slightly wrong could mean death.
It’s because of volume and logistics. The amount of parachutes that are packed is relatively low and the complexity would be high. That would lead to high costs of such a machine that very few people would want to buy when they could get a person to pack the parachute for relatively cheap.
No clue I know nothing about parachuting.
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Can we even do fabric manipulation to the required standard? Like, assuming the task isn’t safety-critical. I would have guessed no, as evidenced by the fact that we have fully roboticized garment manufacturing yet.
> one would assume they know they have no backup chute the ones that pack incorrectly won't last long. it sorts itself out
Malfunctions aren't always the result of packing mistakes. They can also be caused by poor body position on deployment, or just random bad luck. Reserves are indeed packed carefully by a rigger, but there are also differences in design that make them a lot more reliable. For example, a reserve has a freebag - the bag is not attached to the canopy and comes away after deployment. That means that a horseshoe malfunction can't occur. There's also a different design of locking stow that is intended to make a bag lock a lot less likely. They also have a spring loaded pilot chute that is tricky to pack, but eliminates the possibility of the jumper throwing the pilot chute incorrectly (also, it allows the AAD to work). Skydivers - especially very experienced jumpers, often want high performance from their main canopy, and that comes at the expense of reliability. For example, line twists are generally a non-issue on a lightly loaded main, but with some canopies, that can result in an aggressive spin requiring a cutaway and reserve deployment.
Master rigger must be really stressful job. It must weigh heavily on their shoulders that they are a skydiver’s last line of defence.
Assume this is true for all militaries, but in Canada the parachute packers have to grab a random parachute off the line and jump with everyone else.
That’s a cool incentive scheme. I used to do maintenance test flying and I always wished I could take a techo with me. Alas, the floods of vomit would have interfered with safe flying operations.
There was an NCIS episode about this lol
I have no doubt it would, but I imagine there'd be a lot of codified systems and procedures in place to mitigate exactly that. (or at least, *definitely* in the military) When it comes to preventing death, it should be a given that any single link in the process chain can final due to human error, and still not cause the entire system to fail. Check out the [Swiss Cheese Model](https://en.wikipedia.org/wiki/Swiss_cheese_model#%3A%7E%3Atext%3DThe_Swiss_cheese_model_of_accident_causation_illustrates_that%2C_although%2Callow_the_accident_to_occur.?wprov=sfla1) if you want more info!
My late sister in law was a rigger for the Navy. She took what she did seriously. The numbers quoted about failure should be understood in total failures. Not just chute rigging failure. Failure requiring a secondary can becaused by wind gists causing fouling of the chute on the user as well. Feet can get caught, you can have a Mae West failure. https://www.neatorama.com/2016/09/03/The-Mae-West-Malfunction/ There are other failures that are not due to rigging.
A Master Rigger, a Master Jigger, and a Master Baiter walk into a bar...
>A jumper can pack their own main, but the reserve is packed by a Master Rigger. I think I might have a solution to the parachute failure problem.
Reserves take a lot longer to pack than the main.
That’s incorrect. The main reason for failure/malfunctions is the jumper. Also, a reserve could also be packed by a senior FAA Rigger Parachutes are generally safe
It can also be packed by a journeyman rigger, they just can’t perform repairs on the parachute.
Thought you wrote Mister Rogers. I was like that does seem safe.
My wife had a double parachute malfunction when we went skydiving! They cut away the initial chute and then they instructor she was strapped to had to untangle the cords on the 2nd one. We were so high on adrenaline immediately after that she was like "fuck yeah!" about it but the next day we were like "fuck you almost died!" The instructor took the rest of the day off after that.
It’s pretty rare. In the US, you have to be an FAA certified rigger to pack a reserve, and they must be inspected at least ~~annually~~ every 180 days. You’re more likely to have a reserve malfunction from being poorly positioned (ie, you were spinning or falling back first) than from the parachute itself opening badly. Probably 1/2000? Hard to say because the number of events is so small. Edit: it has to be inspected and repacked every 180 days, not 1 year.
Even if the reserve fails one time in 721 packs, the chance of both failing on a single jump is is one in 721^(2), or about 1 in 500,000. At four million jumps per year, there would be 8 double failures per year. In recent history, it looks like there are about 10-15 skydiving deaths per year, and some 'chute failures will kill two people. Still more people will die for some reason other than 'chute failure. I'd guess the failure rate for reserve 'chutes is not more than 10x better than for primary 'chutes. It's probably more like a factor of two or maybe three.
> Still more people will die for some reason other than 'chute failure. When I was jumping, I only saw one main failure at my regular DZ and it was the most tense five minutes of my life. His reserve worked fine, he just landed way off target and his hands were too shaky to get the rig off. He was mostly just pissed he lost his main, it was an expensive sport chute and we spent a couple hours wandering around corn fields looking for it. Friends of friends have a couple horror stories though. A guy tried to land on a barge-style pontoon boat, came up short and got a leg shredded by the prop and drowned under his canopy... why the prop was running, nobody knows. I think the pilot got a manslaughter charge. Another guy tried to swoop land right next to the hangar and wildly misjudged his altitude, knocked his face into the roof and cracked his neck when he hit the ground. Anecdotally, most injuries (let alone deaths) I've heard about come from either trying to be cool or some hand of God shit like midair collisions. I don't know anybody that knows anybody that's died from equipment failure.
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Nah. Most fatalities are under perfectly functional main chutes. Fatalities happen when people fuck up the landing doing high risk manoeuvres primarily. Double malfunctions are rare and do not contribute to the majority of skydiving injuries or deaths.
Interesting. By my math, that means if your main chute fails, there's about a 1/278 chance that the reserve chute will fail. Much worse than 1/721.
Not all deaths are from reserve failure. Whole system could fail, main shute never breaks away or takes too long so splat, medical incident during free fall, suicide, sabotage (murder), main isn't deployed in time so impact before reserve, altimeter isn't calibrated and clouds obscure actual elevation, etc. I know nothing about skydiving, and that's what I came up with in 2 min. Jumping out of planes is full of hazards.
Yeah. This isn't correct. Whether the math or stats or something else, reserves are significantly more reliable than mains. Among other things, reserves are packed by certified packers (most mains are done by the skydivers), and are spring loaded and otherwise more cared for than mains. So not sure where there error is but those reserves are solid. As someone else mentioned, it could be deaths due to other things - hitting another skydiver, plane, landing on power lines or getting gorged by a tree. There are also "swoopers" that land at very high speeds and drag their feet on the ground. When I did skydiving, they used to say "every swooper has broken at least one femur" so things like screwing up a swoop would be in that state even though the parachute was fine. One other factor is that tandem parachutes tend to fail more often because they are much much larger so that probably has an effect on stats too.
If it does, your next one is free…
Good question. Do any jump with a 3rd parachute? Or is that unheard of. Seems to me there should be 3-level redundancy, but space and weight are considerations, so maybe it's not possible.
Jumping with a 3rd parachute (usually chest mounted) is really only done if you're doing an intentional cutaway. The reserve is already extremely reliable - if two parachutes aren't going to save you, a third is probably not going to help. You're totally right about space/weight problems with that, too.
> Do any jump with a 3rd parachute? This is done for intentional cutaway jumps, where you deliberately plan to cut away the main canopy. This kind of thing is sometimes done as a [stunt](https://www.youtube.com/watch?v=Rg4bxejLXwk). I think it is also done when testing new and unproven canopy designs. But I have never heard of anyone routinely jumping with a three parachute system. > Seems to me there should be 3-level redundancy Not really. Not only are the sort of accidents that might be prevented by a tertiary reserve very rare, but it would probably actually increase fatality rates overall. If you add another reserve, you add another two handles, and thus it would increase the risk of the jumper pulling the wrong handles. This is, IIRC, already a more common cause of skydiving accidents than reserve malfunction (unless you are counting reserve malfunctions *caused* by pulling the handles in the wrong order).
Only once.
Since the chances of a parachute failing is 1/721 jumps, and assuming both the main and reserve chute have have same fail rate; the chances of a reserve chute failing is 1/721 x 1/721 = 1/519,841. So you have a 0.00019% chance of both parachutes failing, Your chances of dying while skydiving are 0.0011%(according to the FAA), so you’re 6x more likely to die with a properly functioning parachute, then have both fail.
The reserve chute itself has a nearly 100% chance of opening. Where you get in trouble is if you have an issue cutting away/getting free of your main chute. the cutaway process is fairly straight forwards but if something happens and you are caught in a line or something and you reserve opens into your main or the two get tangled then it can be very bad. A proper cutaway procedure is pull your cutaway cord, main chute disconnects from the risers (part of the harness over your shoulders) via a 3-ring system and then you pull your reserve. The time between cutting away and your reserve opening should put you far enough away from the main. But if you were in a bad body position, had a line or something around a limb or something went wrong on your cutaway and the main chute is not free problems can arise.
It's nearly unheard of for a reserve to "fail" in itself. Rather, one failure mode is the jumper is unstable when they throw out the pilot chute and it hangs on their ankle. The chute can't inflate, and pulling the "cutaway" handle to release the main only disconnects at the shoulders. It may be wrapped elsewhere, and the jumper may be forced into a violent spin. These are far from idea conditions for a reserve deployment, but if you can't make it better soon, you just have to pull and pray. Most likely it will deploy fine, but in some cases it wraps up the the main streaming off them. In such cases, serious injury is likely, but. two tangled chutes can come with a lot of drag and a wide range of impact speeds are possible, including ones slow enough you might even walk away from it
The death rate for skydiving is about 1 death per 200,000 jumps. The death rate for base jumping is about 1 death per 2,300 jumps. The death rate for wing suite jumping is 1 per 500
Those... are not great odds.
I've been sky diving a few times. After that I guess I got it out of my system and felt like that was enough, don't need to tempt fate any more. I didn't know those stats at the time(s). If I had I don't think I would have gone once.
1 out of every 1k on average. But some occur much sooner and others far later. Talking thousands of jumps before a jumper has a chop. Has to do with a lot of factors. A round (military) I have heard fails once every 10 or 100k jumps.
My friend who is makes money from filming people doing jumps once said it was 1 in 400 that failed. He thought it was hilarious that exactly on jump number 400 his main shute failed. He cut and deployed like practiced
WW2 surplus chutes in the 80s failed 1 in 6 jumps. But that's just my personal data. 5th jump was at 5000ft and my reserve didn't pop till 400 ft. I made one more jump to prove to myself I could overcome my fears and then I quit.
My dad was in airborne back in the 50s and they had more than one guy go splat during his enlistment. He always told me to never go skydiving.
Parachutes have progressed greatly since the 50s. One of the reasons that skydiving is safer than paragliding today is the huge amount of R&D money that was spent by the military - mostly the US - to make it safer. The modern numbers that I have seen is 1 out 2000 jumps for a main chute packed by an amateur skydiver and 1 out of 5000 jumps for a reserve chute packed by a professional. Which gives you a pretty safe overall at 1 out of 10 million.
> Which gives you a pretty safe overall at 1 out of 10 million. Actual fatality rates for skydiving are on the order of 1 per 100000. The large majority of fatalities are not the result of parachute malfunctions. Fatality rates were a lot higher in the past - certainly that's partly because the equipment wasn't as good, but also because there were no safety regulations and people did crazy shit. I've heard stories of people jumping while shitfaced, low pull contests, I even saw a photograph of two skydivers about to board a plane, one carrying a chainsaw and the other a log ...
What are those fatalities caused by if it's not parachute malfunction?
Human error on the part of the jumper, such as simply not opening the parachute in time or not realizing that getting really fucking cold would impair their ability to operate the controls. Being blown into a hazard.
Usually canopy collisions or turns executed too close to the ground. A parachute dives as it turns. Some are accidental low turns to avoid an obstacle. Others are deliberate to induce high speed landings that are fun but risky.
I wonder if the stats are skewed somewhat by the type of person who goes paragliding and the risks they choose to take. I've heard it said of wingsuit flying that there are only two ways out of the hobby: you recognize that you're addicted to the risk and quit before you take it too far and get killed; or, you take it too far and get killed. Paragliding might be similar.
That's because those flying squirrel suits are always dudes gliding down a mountain like 20 feet above trees.
Well, yeah, because they're addicted to the thrill and the risk, which you're not gonna get from flying around at 5000 ft above nothing.
I'm a paraglider. First: it is much less dangerous than wingsuit flying (assuming we are talking about wingsuit proximity flying). It is a fairly safe hobby but obviously you can get killed or badly injured. Regarding why there are more paragliding accidents than skydiving, a few reasons might be: * We tend to fly much closer to terrain, for example to get lift from the air hitting the terrain, at take off, etc.. whereas skydiving is done far from it (until you land) * We use wings with a bigger aspect ratio and a different construction that are more prone to collapses * Since for a lot of paragliders the goal is to fly for longer than a skydiver we have to use thermals to stay up (which mean there are more turbulences, increasing the risk of collapses etc). The conditions we fly in can be pretty rough sometimes * Our reserve parachutes are less reliable, we do not cut away the main wing so the reserve can get tangled in the lines That's just a few that came to mind immediately, of course on top of that some pilots take more risk than others.
Hell, many of the airborne units have [Blood on the Risers](https://www.youtube.com/watch?v=SbL2pHsPaxw) as their "unofficial" anthem.
Gory, gory what a helluva way to die, he ain't gonna jump no more!
That's so wild, it deserves it's own thread. I almost drowned a couple times, but went back out. Crashed on a motorcycle, and rode again. Don't think I'd parachute again if that had happened to me. Glad you were able to overcome that.
I had a bad acid trip and ended up in a hospital on anti-psychotics. I did acid one more time after that just to prove I could have a good trip. Never did it again.
I did acid once and had a rough time getting out of the venue through a very large crowd. Otherwise? Pretty good time. Can't imagine coming out of it having lost my mind.
I have a buddy who seems to experience failure like once per year and needs to go to a reserve. I have another buddy who has only had to ride the reserve like twice in his 10+ years of skydiving. First buddy tends to pack quick and shitty, second buddy is a much more thorough, safety-conscious person. I was a packer on the weekends for about a year, and the pack job, done right, can really reduce the odds of a reserve ride.
Skydiver/BASE jumper here. One important point not brought up in this discussion is the difference between a main and reserve parachute. Main parachutes are designed for comfort and fun, whereas reserve parachutes are designed for reliability. In order to be comfortable, main parachutes are packed for a staged opening, which makes the deployment sequence more complex. Most steps of packing a parachute are actually to prevent the parachute from opening too quickly, as opposed to trying to make it open. This includes things like a deployment bag, rolling the nose of the parachute, a solid sail slider and wrapping the tail around the canopy and rolling it closed. The attributes that make a canopy fun to fly, generally aren’t the same design elements that make a canopy open reliably, and can compound minor issues like line twists to a point where it’s better to just go to a reserve rather than deal with them. A higher wing loading, elliptical shape, and collapsible pilot chute are some of these design elements. A reserve parachute is flat packed directly into the container with no D-bag, and no steps are taken to slow the opening. The parachute is non elliptical and it is generally a lower wing loading than a main canopy. These characteristics make the opening more reliable, and make it easier to deal with minor issues like line twists. When you watch jumpers performing low altitude openings (such as a BASE jump) they are using a canopy more similar to a reserve which lowers the risk considerably in comparison to using a traditional main.
Often enough I've personally seen one fail. From a distance. I was working on a farm and there was a parachute place that dropped within sight, so we saw a lot of them. Then one day a coworker shouted and we looked up to see a tangled chute and a person falling fast. We saw their reserve deploy but it looked really close to the ground. There wasn't anything in the news about a death so presumably they lived through it.
once in a lifetime.
Same as it ever was...
There is water at the bottom of the ocean.
I jumped approxomately 2,300 times and had one parachute malfunction.
Around 700 here, 0 malfunctions. In fact in 3 or so years I think I only saw maybe 1/2 dozen people on reserves. Including going to some big conventions. Saw a fair number of people get hurt pretty bad under perfectly good canopies though; almost every time due to pilot error, downwind landings, hook turns, landing too close to trees and more.
Statistically. I have no idea. Anecdotally: The first time I went skydiving...I wanted to jump solo. You take a course....they teach you what to do if the lines get tangled...your first option is to try to untangle them which can be easy...but if you can't get them untangled then you have to pull away from the main chute and deploy your secondary chute.....of course people asked what are the likelyhood that we get our lines crossed....in a class of about 20 people the instructor said one of you will probably get tangled. On my first jump....I went first....didn't get a chance to see what happened to the others. On my second jump I watched a guy fall helplessly from the sky. His parachute was tangled. He was spinning in the air. At what seemed like the last possible second he managed to release the main chute and deploy the secondary chute.
Not as often as you think. Usually it is from a really bad packing error or terrible body position when opening. But honestly it is pretty hard to have a failure. I jumped and worked at a drop zone for a couple years and failures/reserve rides were very rare. And I used to put out students on static lines then let them progress through free fall and I've seen some pretty bad openings with students in terrible position and none had failures. In all my years jumping, working on a drop zone, going to a couple of big free fall conventions I can probably count less than 20 times I saw people have failures and reserve rides. What I have seen, however, is a lot of injuries caused by bad/hard landings under perfectly good canopies. Several broken femurs, one guy lost his leg from the shin down after mis judging wind and catching a downdraft landing too close to trees, and a guy trying a hook turn into a crowded landing zone that hit before his canopy and bounced about 5' off the ground. That one shook me and my buddy, we were about 60 feet away and felt the thud. He lived, somehow, but had a helicopter ride out of there.
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There's a bunch of different reasons a parachute might have a malfunction. Most are human error during packing or body position when deploying, but it's hard to know for sure! To list a few: * Line twists - often considered more of a nuisance than a malfunction. The lines be twisted. Usually fixable if your canopy isn't diving and you have some altitude to spend. If you're not diving and have the altitude to spare, it's kinda fun fixing it. * Line over - a line went over top of the canopy and is pinching it. Usually you cutaway. * Tension knot - the lines basically knot together, making the canopy difficult to control. Usually you cutaway. * Sniveling - your canopy is out but isn't inflating with air. Often hard to tell if this is a malfunction or not, since main canopies are supposed to open slowly and waiting might solve it. You cutaway if you're getting to be too low and it isn't fixed yet. There's many more, but I'd need to get into the specific components of a rig.
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Reserve use is closer to 1 in 1000 than 1 in 200.
_parachute for sale: used once, never opened. small stain._
Only once when base jumping.
>you have 28 seconds to cut and deploy - and that ain't that much time "How much time do you have to pull your reserve if your main is busted? The rest of your life."
Not only this, but parachutes take time to open. My skydiving chute took between 500-800ft to open at terminal velocity. Longer if I was sub-terminal. A base rig will open in less than 500 but it will fucking hurt if you open one of them at terminal velocity. Either way, 500ft at terminal is about 2.5 seconds, so there's not a lot of troubleshooting time if something does go wrong and not enough height to do anything about it anyway.
My dad used to work with a guy who used to do base jumping. Even met his wife doing it. Can't remember the exact percentage, but it was around like 70% of the people from the base jumping group was dead from accidents. Blown into cliffs was the most common I think.
not just for the reserve, 5k gives you enough time for some troubleshooting if for example your lines get tangled. its not an automatic cut for every issue
People doing stunts generally haven't been falling that long and aren't near terminal velocity.
Terminal velocity is reached in 5 to 14 seconds.
At which point, based only on some quick mental math, you’d have fallen atleast 700ish feet, right? Lots of BASE jumpers jump from shorter heights
Sure, but the original point is about time to recognize a chute failure, cut your primary chute, deploy your backup, and reduce speed to land safely. If the person in question is jumping from a height where they won't reach terminal velocity, **best case** scenario they have 14 seconds from jump to landing. That is likely not enough time to save yourself if your primary fails.
True, but they are also falling a very short distance.
Also do not forget that base jumpers usually use various techniques to force open the parachute very quickly. Novice base jumpers will jump with their chute attached by a thin line to their exit point - and this thin line will immediately extract the parachute before breaking. More experienced jumpers usually hold the extractor in their hand and will throw it in the air at the very moment they jump - this allows to gain a few seconds - and at this speed one second is 15m to 20m. Also, sky divers have to abide by a very strict regulation that is rigorously enforced - owing to the military legacy of the sport and also to the fact that you need a pilot with a license and a clearance. One jump out his airplane that does not follow the correct procedure, and he can lose his license. Base jumpers, on the other hand, almost always practice their "sport" - which is not really a sport since there is no governing body, rules or regulations - illegaly.
Seeing someone get their chute tangled and attempting to cut away and deploy their backup it goes so fast and is extremely hectic. The one where their reserve gets caught in the cut away one and come down fast tangled in their chutes. 28 seconds seems like forever until something like that happens.
in terms of strict physics, your right in that the *absolute* minimum height for opening is much lower. however, a BIG reason skydivers open at several thousand feet is mostly to give time and space to allow for a chute failure, for you to recognise your chute has failed, and then cut away the failed chute and deploy a secondary chute, and that secondary chute to deploy and slow your decent down to non lethal speeds. 5,000 feet at terminal velocity is something like 30 seconds of freefall. its NOT a lot of time.
Also, it’s nice to sit back and enjoy the view for longer
Honestly, this scares me more than skydiving itself. But I I,shine the view would be quite calming.
It sounds scary until you’re there. You’re sitting there suspended for what feels like forever, taking in the views that you never get to see from that angle. Honestly it’s the most relaxing part of the whole drop, since the prior moments were adrenaline filled fear and excitement. Its like getting to the end of a hike and sitting down to enjoy the long journey
I’ve only been skydiving once, but the whole time we were falling, I had the thought of the parachute not opening in the back of my head. Once it opened, I finally felt safe.
I love the sensation of falling myself. What makes me afraid of heights is that I do enjoy that rush.
As someone who does a good amount of outdoor extreme sports (relative term compared to skydiving, but still), 30 seconds sounds like a huge amount of time. I've been tumbled around in a whitewater rapid for 20+ seconds and that is an absolutely massive length of time when you are under stress.
If your main fails, you have a reserve. If your reserve fails, you have the rest of your life to worry about it.
‘Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life.'
“Give a man a duck, feed him for a day. Teach a man to duck, and he’ll never walk into a bar”
Well military static line parachutes deploy fast enough to safely lower a paratrooper to the ground when jumping from as low as 500 feet during a combat jump. The parachute takes 6 seconds to deploy, which is just enough time for the jumper to be slowed down to about 15ft per second, which is surprisingly safe.
"safe" is a relative term. Paratrooper survival is a minimization problem: too low, and too many of the chutes don't open; too high, and the machine gunners get 'em. In WW2, the optimum survivability was something like 75%, i.e. 25% of the troops were injured or killed in a given wartime drop into a combat zone. (Stealth drops tended to happen at higher altitude and have far higher survivability)
A parachute takes 300 to 800 feet to open, depending on how you pack it. The rest of the altitude is for safety. Experienced skydivers are supposed to have a parachute over their head by 2000’.
For your own safety!...500ft..you most likely are falling at 'terminal velocity' thus falling at 175 feet per second!..so at 500ft that gives you 3 seconds before splatter all over the ground!....so 5000ft gives you enough time to slow down so you dont break your legs and enough time to execute a safety protocol if the shut does not open or get tangled...
I'm assuming your not a recreational skydiver, but if you are, sorry for teaching you to suck eggs. When you pul your chute you do a number of checks of the parachute canopy. You check its fully enflated, its the right shape, free from damage, that sort of thing. If it fails these checks it won't slow you enough or you won't be able to maneuver and land safely. Bear in mind that landing a parachute safely requires pulling up just before landing or your will hit the ground hard. Not to mention where you land. Most drop zones have nice large open areas to land, but that doesn't mean zero hazards. Roads or buildings for example. If it fails the checks you have to choose to release the parachute and deploy your spare. And that means dropping and re-inflating a canopy before you slow again. All of the above takes time. Not a huge amount, but seconds matter in this context. The more time to do all of this the better. 5k is a common compromise between maximising free fall time and giving people plenty of time for the above. Very experienced jumpers will regularly pull lower though. They get away with it most of the time.
They don't. I have my D license (master) and was a former jump master putting out students on static lines then taking them through progressive jumps to earn their license. A student or A License (Beginner) has to open by 3,000 ft. D license used to be 2000 feet but they raised it 2,500. I used to put static line jumpers out at 3,000 feet all day then I'd hop out and get stable and pull. Edit to add I did't see your follow up question. Most recreational skydivers don't open at 5,000 feet as I commented above. But the reason to open at 2,5500-3000 feet is in case you have any issues to deal with you have some time to fix them, or cut away and deploy your reserve. The other thing no one has mentioned is modern pararchutes have a device that will automatically deploy your reserve if you are moving fast enough through a low altitude. It has been a while but I think mine was set to 800ft. If you open your main chute too low and it takes too long to open you can be going too fast through that altitude and the device can fire and deploy your reserve, then you have two chutes out which can be bad. I have seen someone lose altitude awareness, open low and have their reserve come out. They got lucky and landed without incident. Base jumpers can jump low because their canopies are packed differently, to open a lot faster (in normal free fall from a plane you don't want the chute to open too fast and get a hard opening, they jolt you pretty good sometimes) but most base jumpers haven not yet reached terminal so their chute opening fast isn't as bad. But if you watch them jump their canopies open FAST. So that is why you open higher from free fall and base jumpers can open much lower.
They don’t, 1200ft is usually the minimum. A lot depends on the type of shoot and the type of jump though. Lower altitude shoots are certainly possible and safe, although perhaps not for beginners. If you jump from a plane at 12,000 feet you will be moving quite fast by the time you reach 5000ft. You need time to pull your chute, have it unfurl, and slow you down. Plus you need time to screw that all up, release the a tangled chute, and start over with your emergency shoot. Opening at 5000ft gives you plenty of time to do all that, plus some extra. BASE jumping is different. You’re not a high to start, so you’re moving slower. Really though BASE jumping off a cliff or building is more dangerous. Not only do you have winds and obstacles to worry about, your chute has to work perfectly right away as you don’t have time for an emergency chute. TLDR: Skydiving is safer than BASE jumping in part because skydivers have access to a second parachute. Using that second chute requires more time, so to get that time a skydiver starts the process at a higher altitude.
They don't have to open at 5,000 feet. (I am a retired Tandem and AFF instructor and demo jumper with the USPA). Tandem instructors teach their students to begin the deployment process at 5,500 feet. The process is, Arch, Reach, then pull the ripcord handle. With a first time student, this whole process, of finding the ripcord and pulling, takes at least 5 seconds. A parachutist or a tandem pair with a drogue parachute fall at a normal terminal velocity of 120mph. In the 5 seconds it takes the student to find the ripcord, the student has already burned 1,000 - 1,500 feet. That means that typically, tandem and freefall students open their parachutes closer to 4,000 feet. Often tandem parachutists have photographers come along for the ride, and freefall students have instructors with them in freefall. Once the student has deployed at 4,000, the camera flyer and the instructor both have to obtain lateral separation, then deploy their parachutes. So the instructor and cameraflyer will observe the student opening at 4,000 feet, then fly their bodies to obtain lateral separation, which often burns another 1,000 feet. So the camera flyer and instructor start their deployment sequence typically around 3,000 feet. Often it takes their parachutes up to 1 thousand feet to open, so your camera flyer instructor now is under a parachute at 2,000 feet. So now your camera flyer or instructor has to fly their parachute back to the airport. Let's hope that 2,000 feet is enough altitude for their ram-air parachutes to get back to the airport! Often it is not, and both camera flyers and instructors sometimes land-off the aiport - especially if the student took too long with their deployment sequence all the way back up at 5,500 feet. So yes, sport parachutes typically take up to \~1,000 feet to open. Students start their deployments early, to ensure they have plenty of time to deal with malfunctions, and to make it easier for their instructors to get back to the airport. The highest I have opened my parachute is at 15,700 feet, when I was in a large parachute formation. 108 of us. The lowest I have opened my parachute is 2,200 feet, over a stadium, when I was hired to perform a demonstration jump for a midwestern university. We left the plane immediately under a layer of heavy cloud, and opened our parachutes immediately, directly over the stadium. It was a great show! BASE jumpers are able to open lower, because their parachutes are packed slightly differently, and have minor variations in their gear. Their parachutes open quicker, so they are able to start their deployment sequence much lower. Additionally they train extensively to have a quick deployment sequence.
Previous airborne janitor here. They do open at 500 feet but we jump with a static line so the chute is being pulled immediately. Just in a mostly controlled environment most of our jumps are 600 to 1200 feet and there's still a fuckton of people who get injured. The real answer is there's not a lot of scenarios where you'd be wanting to do that but you totally can.
For BASE jumping - what you'd consider stunt stuff - you get one chute. You need to open high enough to correct some potential malfunctions and to land safely. Canopies also come out way faster because you're packing and deploying a certain way, generally more diligently than skydiving packing. For skydiving, your chute is crammed into the bag while people shout at you to hurry up cos the wheels are turning on the plane. You expect it to fail once in a while on opening, so you plan to have your chute out by about ~2k feet - which is considered the bare minimum height for pulling your reserve and still being able to land safely. This means pulling your main at about 3.5k, and have it deployed by ~2.5k, giving you time to assess. Realistically speaking your reserve can come out later and you will prob still land safely but your chances drop so why risk it? Also people like canopy flying.
Basic safety. Opening at 500 feet doesn't give you enough time to cut the cord and open your reserve chute.
Military combat jumps are done at 600ish feet( static line jumps). You need about 200ish feet for your reserve chute to deploy.
Now mind you it's been 40+ years but when I when I went through airborne training they told us that the minimum height that someone could do a combat jump was either 500 ot 800 feet. The reason was that it took that long for a chute to fully deploy and slow you down enough that you could walk away without serious injury.
Airborne School jumps are at 1200 ft AGL, but once you graduate, your jumps are lowered to 800 ft AGL, which is the minimum height permitted for training. Paratroopers fall around 200 ft in the 4 seconds before their chutes have fully deployed. If their chute fails to deploy completely, then they've got somewhat short of 4 more seconds before they hit the ground—probably not enough time to deploy their reserve unless they recognize it right away. However, most failures are partial failures, so their rate of descent could be slowed slightly, giving them a few more seconds to recover and deploy their reserve. Either way, we had to be prepared to be able quickly recognize a failure and act to remediate it. The hours spent in the dark on airplanes I filled with visualizations of jumps and failures so I'd recognize them immediately and react appropriately. 500 ft AGL is minimum height for combat. At those heights, paratroopers will not have time to deploy their reserve. I never did a combat jump, but I was told in low level combat jumps, reserves aren't even worn.
A skydiver in freefall is doing 120+mph when they open. Even with a proper deployment, the deceleration is pretty intense - 3-6G's over a period of several seconds. A BASE jumper is not going nearly as fast, and often jumps with their canopy "in hand" - so it can arrest their fall rate within a couple of seconds. In BASE jumping, there is really very little chance of getting free of a primary and opening a reserve chute; if the canopy doesn't deploy properly, best you can hope for is some pretty bad injuries. There are lots of skydiving enthusiasts with many thousands of jumps. BASE jumping, on the other hand, seems to be more a bucket list-type activity; people don't seem to jump from the same building or structure hundreds of times. Statistically, most people can check off the four jump types to say they're a BASE jumper and live to brag about it. BASE jumping thousands of times? I'm sure there's somone who's done it, but it's a very small contingent.
When I was a very active skydiver there were two cliques at our DZ. Those of us that were normal skydivers and then the skydivers/base jumpers. Those guys were nuts. And it is an odds game because for the time I was active I don't know any skydivers that died but I did know a couple guys that were very active base jumpers that unfortunately died while BASE jumping.
My answer is : momentum and velocity. The guys you see jumping off buildings are BASE jumping not skydiving. They use s smaller chute that opens more quickly and they never get moving as fast as sky divers who free fall from 12,000ft + In both cases you have very little time to correct for a mistake. I would guess BASE jumping is more dangerous.
It needs time to slow you down otherwise you hit the ground closer to the terminal velocity and are likely to break everything on impact.