Unplanned Freefall? Some Survival Tips (2001)(greenharbor.com)
greenharbor.com
Unplanned Freefall? Some Survival Tips (2001)
http://www.greenharbor.com/fffolder/carkeet.html
120 comments
holy crap - i've read about that flight so many times - it's one of the stories that keeps me relatively calm in turbulence* (along with the video of the famous 777 wing failure test) - they both give me solace in how much a plane is built to survive (yet, i read a lot about plane crashes, and also know what small things/mistakes/flaws lead to the opposite outcome)
* (obvi unfortunate that it happened and people had to experience that)
and sorry to hear about your father.
* (obvi unfortunate that it happened and people had to experience that)
and sorry to hear about your father.
Agreed, and I like to always think of turbulence as a demonstration that the plane is working as intended!
I am somewhat interested in reading about plane crashes and such. Are there any books/resources you can recommend to me?
The youtube video of the guy hangliding which took off without him strapped in is pretty incredible. He survived by holding on, only ended up breaking his wrist: https://www.youtube.com/watch?v=dLBJA8SlH2w
There's a guy on reddit making a written series on air crashes, with articles every Saturday and it's been going for a few years now.
https://www.old.reddit.com/r/AdmiralCloudberg/
It's obviously not extremely technical (though a lot more than I'd have thought), and it's probably nothing you can't get from more in depth websites but it's neatly organized, well written and the articles are getting better and better. I like that he keeps conjecture to a minimum too but still points out what lessons can be learnt from the tragedies.
The only thing is that I'd recommend reading it through the Medium link he posts in the comments instead of the linked imgur albums. It's a much better experience
https://www.old.reddit.com/r/AdmiralCloudberg/
It's obviously not extremely technical (though a lot more than I'd have thought), and it's probably nothing you can't get from more in depth websites but it's neatly organized, well written and the articles are getting better and better. I like that he keeps conjecture to a minimum too but still points out what lessons can be learnt from the tragedies.
The only thing is that I'd recommend reading it through the Medium link he posts in the comments instead of the linked imgur albums. It's a much better experience
There's a TV show that is kinda good: "Mayday". It may also be called " air disasters" or some such in different locations.
Edit: here's a wiki link:https://en.m.wikipedia.org/wiki/List_of_Mayday_episodes
Edit: here's a wiki link:https://en.m.wikipedia.org/wiki/List_of_Mayday_episodes
Personally I just go through Wikipedia articles, some are a little short on details but will often enough link you to more I'm depth information.
I end up just jumping from one article to another through the "see also" links and similar accidents
Edit: occasionally you'd also find a podcast episode covering a particular crash or documentaries like air crash investigation or similar
I end up just jumping from one article to another through the "see also" links and similar accidents
Edit: occasionally you'd also find a podcast episode covering a particular crash or documentaries like air crash investigation or similar
If you like documentaries there is a whole genre on Youtube that covers air incidents. Lots exist but the ones I follow are Mentour Pilot (technical / crew focused analysis from an airline pilot), Wonder (more TV style focused on the passengers and stories), Air Safety Institute and FlyWire- scott perdue (small-time incident analysis geared towards educating private pilots).
More than just the accidents, you can keep up with all the random incidents that are reported (and could potentially have been worse).
Eg last month "Screwdriver tip left in engine during maintenance results in engine failure on take-off"
https://aviation-safety.net/
Eg last month "Screwdriver tip left in engine during maintenance results in engine failure on take-off"
https://aviation-safety.net/
fell 30,000 feet over 2.5 minutes and corrected tens of seconds before impact with the Pacific
What does "corrected tens of seconds before impact" mean here? Thanks.
What does "corrected tens of seconds before impact" mean here? Thanks.
If they hadn't leveled out and stopped descending, in a few more seconds they would have impacted the Pacific Ocean.
Correct, that's what I meant, thanks.
"Tens of seconds" versus "a few seconds" is quite different in this scenario.
To paraphrase THHGTTG:
What to do if you find yourself falling from a great height: consider how lucky you are that life has been kind to you so far. If life hasn't been kind to you so far, which is not unlikely given your current circumstances, consider how lucky you are that it won't be bothering you much longer.
What to do if you find yourself falling from a great height: consider how lucky you are that life has been kind to you so far. If life hasn't been kind to you so far, which is not unlikely given your current circumstances, consider how lucky you are that it won't be bothering you much longer.
about halfway down remember to shout "so far so good!" in case anyone is listening.
And about 90% of the way down, I would suggest “So long, and thanks for all the fish!”
“Another thing that got forgotten was the fact that against all probability a sperm whale had suddenly been called into existence several miles above the surface of an alien planet.
And since this is not a naturally tenable position for a whale, this poor innocent creature had very little time to come to terms with its identity as a whale before it then had to come to terms with not being a whale any more.
This is a complete record of its thoughts from the moment it began its life till the moment it ended it.
Ah … ! What’s happening? it thought.
Er, excuse me, who am I?
Hello?
Why am I here? What’s my purpose in life?
What do I mean by who am I?
Calm down, get a grip now … oh! this is an interesting sensation, what is it? It’s a sort of … yawning, tingling sensation in my … my … well I suppose I’d better start finding names for things if I want to make any headway in what for the sake of what I shall call an argument I shall call the world, so let’s call it my stomach.
Good. Ooooh, it’s getting quite strong. And hey, what’s about this whistling roaring sound going past what I’m suddenly going to call my head? Perhaps I can call that … wind! Is that a good name? It’ll do … perhaps I can find a better name for it later when I’ve found out what it’s for. It must be something very important because there certainly seems to be a hell of a lot of it. Hey! What’s this thing? This … let’s call it a tail – yeah, tail. Hey! I can can really thrash it about pretty good can’t I? Wow! Wow! That feels great! Doesn’t seem to achieve very much but I’ll probably find out what it’s for later on. Now – have I built up any coherent picture of things yet?
No.
Never mind, hey, this is really exciting, so much to find out about, so much to look forward to, I’m quite dizzy with anticipation …
Or is it the wind?
There really is a lot of that now isn’t it?
And wow! Hey! What’s this thing suddenly coming towards me very fast? Very very fast. So big and flat and round, it needs a big wide sounding name like … ow … ound … round … ground! That’s it! That’s a good name – ground!
I wonder if it will be friends with me?
And the rest, after a sudden wet thud, was silence.
Curiously enough, the only thing that went through the mind of the bowl of petunias as it fell was Oh no, not again. Many people have speculated that if we knew exactly why the bowl of petunias had thought that we would know a lot more about the nature of the universe than we do now.”
― Douglas Adams, The Hitchhiker's Guide to the Galaxy
And since this is not a naturally tenable position for a whale, this poor innocent creature had very little time to come to terms with its identity as a whale before it then had to come to terms with not being a whale any more.
This is a complete record of its thoughts from the moment it began its life till the moment it ended it.
Ah … ! What’s happening? it thought.
Er, excuse me, who am I?
Hello?
Why am I here? What’s my purpose in life?
What do I mean by who am I?
Calm down, get a grip now … oh! this is an interesting sensation, what is it? It’s a sort of … yawning, tingling sensation in my … my … well I suppose I’d better start finding names for things if I want to make any headway in what for the sake of what I shall call an argument I shall call the world, so let’s call it my stomach.
Good. Ooooh, it’s getting quite strong. And hey, what’s about this whistling roaring sound going past what I’m suddenly going to call my head? Perhaps I can call that … wind! Is that a good name? It’ll do … perhaps I can find a better name for it later when I’ve found out what it’s for. It must be something very important because there certainly seems to be a hell of a lot of it. Hey! What’s this thing? This … let’s call it a tail – yeah, tail. Hey! I can can really thrash it about pretty good can’t I? Wow! Wow! That feels great! Doesn’t seem to achieve very much but I’ll probably find out what it’s for later on. Now – have I built up any coherent picture of things yet?
No.
Never mind, hey, this is really exciting, so much to find out about, so much to look forward to, I’m quite dizzy with anticipation …
Or is it the wind?
There really is a lot of that now isn’t it?
And wow! Hey! What’s this thing suddenly coming towards me very fast? Very very fast. So big and flat and round, it needs a big wide sounding name like … ow … ound … round … ground! That’s it! That’s a good name – ground!
I wonder if it will be friends with me?
And the rest, after a sudden wet thud, was silence.
Curiously enough, the only thing that went through the mind of the bowl of petunias as it fell was Oh no, not again. Many people have speculated that if we knew exactly why the bowl of petunias had thought that we would know a lot more about the nature of the universe than we do now.”
― Douglas Adams, The Hitchhiker's Guide to the Galaxy
The bit I was originally cribbing from above was from a little later, near the beginning of series two of the original radio run: https://www.goodreads.com/quotes/17180-what-to-do-if-you-fin...
La Haine? Subtle, I like it.
Feel silly I had to look up what THHGTTG was. The Hitchhiker’s Guide To The Galaxy
Aim for the whale, not the petunias. They are already having a worse day than you.
As someone with significant skydiving experience, good luck doing any of these things your first time out of a plane. Chances are you'll end up on your back, spinning out of control. If you are lucky you'll end up on your belly, spinning out of control.
If you want to learn how to do any of these things, go to your local wind tunnel and practice. Without that practice, you should just enjoy the minute or so of spectacular views before you go splat.
Also, even with that experience, you'll probably go splat. Best case your aorta will disconnect and you'll bleed out after a few seconds. This is common even when people are stopped by the harness (e.g. by hitting trees). Human body just wasn't designed to accelerate (decelerate) that quickly.
If you want to learn how to do any of these things, go to your local wind tunnel and practice. Without that practice, you should just enjoy the minute or so of spectacular views before you go splat.
Also, even with that experience, you'll probably go splat. Best case your aorta will disconnect and you'll bleed out after a few seconds. This is common even when people are stopped by the harness (e.g. by hitting trees). Human body just wasn't designed to accelerate (decelerate) that quickly.
> enjoy the minute or so of spectacular views before you go splat
This is what I've always said. The only time I'll skydive is if I already find myself falling out of a plane. Then I'll cross it off my bucket list as I go splat.
This is what I've always said. The only time I'll skydive is if I already find myself falling out of a plane. Then I'll cross it off my bucket list as I go splat.
“Look around for a proportionate personal vehicle—some large, flat, aerodynamically suitable piece of wreckage. Mount it and ride, cowboy”
Given that you woke up after falling 20,000 feet, anything that in itself is “aerodynamically suitable” will be high above you by now (1) or, if it dropped of before you started falling, be miles behind you. Even that tightly packed parachute likely has lower terminal velocity, and will be out of reach by now.
I guess your best (not one with good odds, but still best) bet is an airplane door with an uninflated glide that you can tie yourself to, remove from the door, and then inflate.
(1) you can see that with rain showers: it’s the smaller droplets that hit the ground last
Given that you woke up after falling 20,000 feet, anything that in itself is “aerodynamically suitable” will be high above you by now (1) or, if it dropped of before you started falling, be miles behind you. Even that tightly packed parachute likely has lower terminal velocity, and will be out of reach by now.
I guess your best (not one with good odds, but still best) bet is an airplane door with an uninflated glide that you can tie yourself to, remove from the door, and then inflate.
(1) you can see that with rain showers: it’s the smaller droplets that hit the ground last
That’s your top nitpick across all points presented in this survival guide?
I mostly agree, but a nice flat surface would rotate/rock/wave [1] like a sheet of paper. When it's horizontal it will go slowly, but when it's vertical it will go faster than a person. I'm not sure about the average.
Note: This is a nice experiment for ~12 year old students that are learning to measure things in the laboratory. Just get two sheets of paper and make a ball with one of them, and measure the time when they fall from a fixed height.
The time of the ball of paper will have a nice distribution. You can probably measure the time 5 times and have a good idea of the average and dispersion. Moreover, most of the dispersion in the time is due to the problems to start and stop the stopwatch, and perhaps some problems to release the ball.
The flat sheet will dance randomly while falling, and the time will be very inconsistent. I don't remember the details, but you should repeat the experiment like 20 times to get an idea of the distribution. The average changes, but the dispersion is a lot higher an impossible to avoid.
[1] I'm not sure which is the correct word in English.
Note: This is a nice experiment for ~12 year old students that are learning to measure things in the laboratory. Just get two sheets of paper and make a ball with one of them, and measure the time when they fall from a fixed height.
The time of the ball of paper will have a nice distribution. You can probably measure the time 5 times and have a good idea of the average and dispersion. Moreover, most of the dispersion in the time is due to the problems to start and stop the stopwatch, and perhaps some problems to release the ball.
The flat sheet will dance randomly while falling, and the time will be very inconsistent. I don't remember the details, but you should repeat the experiment like 20 times to get an idea of the distribution. The average changes, but the dispersion is a lot higher an impossible to avoid.
[1] I'm not sure which is the correct word in English.
> I'm not sure which is the correct word in English.
would fall like an autumn leaf
would fall like an autumn leaf
I am a leaf in the wind
> I'm not sure which is the correct word in English.
"Flutter", perhaps?
"Flutter", perhaps?
I'm putting this paper experiment in my list of things to do with my nephew when he's a bit older. Neat idea, thanks!
About the correct word: I have no idea what the best word is, but the way you wrote it certainly brought images to my mind of various ways I've seen falling debris act. I honestly wonder if using the "best word" would have been less useful to my comprehension - but I'm in general a big fan of the word1/word2/.../wordN way of describing multi-faceted/ambiguous/complex statements.
About the correct word: I have no idea what the best word is, but the way you wrote it certainly brought images to my mind of various ways I've seen falling debris act. I honestly wonder if using the "best word" would have been less useful to my comprehension - but I'm in general a big fan of the word1/word2/.../wordN way of describing multi-faceted/ambiguous/complex statements.
Hadn't thought of that, it's certainly going to reduce your terminal velocity even if it goes vertical as it probably would.
I wonder if someone will make a computer game akin to Bridge Designer, but for surviving falls. Levels could have various objects released along with your body, and various targets on the ground to aim for, and you can try to survive.
Such a game does exist - check out the Pilotwings series for SNES and N64
> Thirty feet is the cutoff for fatality in a fall. That is, most who fall from thirty feet or higher die.
And to think my friends and I used to jump off a 2nd story balcony for shits and giggles. Even after one of us broke an arm doing it. Just 2/3 of the way towards certain death!
And to think my friends and I used to jump off a 2nd story balcony for shits and giggles. Even after one of us broke an arm doing it. Just 2/3 of the way towards certain death!
Shouldn't the speed ramp up quite a bit in that last 1/3?
Less than 1/3rd of the velocity will come from the last 1/3rd of the fall.
If you’re going X speed after 2 stories, you’d be going sqrt(3/2)X = 1.22X after the last 1/3rd, ignoring drag.
Energy increases linearly with fall height though, and energy is probably what mostly kills you. (Again ignoring drag.)
If you’re going X speed after 2 stories, you’d be going sqrt(3/2)X = 1.22X after the last 1/3rd, ignoring drag.
Energy increases linearly with fall height though, and energy is probably what mostly kills you. (Again ignoring drag.)
Ah, because after that first 2/3rds, you're going too fast to have time to accelerate much more.
At a guess you were a lot lighter back then. The speed of impact would be the same but the total energy to dissipate a fraction of what it would be today. So better not to try that particular trick again.
Oh to have the resiliance and cartilage of a teenage boy! Pretty sure if I did that those stunts at my age I'd win a Darwin award.
I used that particular trick as my escape route during tag. We would play on this structure made from wooden rolls, it spiraled upwards, about 3.5 meters high at the top and I found that I could easily jump down as long as I bent through my knees upon landing and touched down afterwards with my arms. Magic :)
"You can drop a mouse down a thousand-yard mine shaft and, on arriving at the bottom, it gets a slight shock and walks away. A rat is killed, a man is broken, a horse splashes."
Yup. As small kids we would jump from a tree that I wouldn't consider doing as an adult. I don't think terminal velocity is important at that scale but square-cube certainly is. You landed pretty hard but I never heard of anyone getting hurt.
Wouldn't a second story balcony be in line with the floor of the second story, not the roof, so ~10 or 12', not 20.
> 120 divided by 5 = 24. Not bad! 24 mph is only a bit faster than the speed at which experienced parachutists land. There will be some bruising and breakage but no loss of consciousness to delay your press conference. Just be sure to apportion the 120-mph blow in equal fifths. Concentrate!
Sadly this is not how it works. Kinetic energy is proportional to the square of velocity, and so if you can equally split the impact energy 5 ways, it's as though each impact is at 54mph. A bit harder to absorb.
Sadly this is not how it works. Kinetic energy is proportional to the square of velocity, and so if you can equally split the impact energy 5 ways, it's as though each impact is at 54mph. A bit harder to absorb.
And it's not something the untrained person is going to have any hope of pulling off. There is a grain of truth in the assertion--if the surface hit isn't too hard and the landing fall is executed perfectly survival is possible. Done correctly the energy is dissipated in breaking a whole bunch of bones but the truly vital areas aren't subjected to lethal force.
The author missed a very important strategy. Look for a transition.
If you manage to land on a nice slope, catching the transition will vastly reduced the peak force. The angle and composition of the slope will determine your outcome. Soft spring snow is probably best. Powder snow would have a much lower impact force, but most like you'll become deeply embedded and suffocate. Grass, shrubs or loose soil would be the next choice. If it's rocky or trees terrain you're probably toast
If you manage to land on a nice slope, catching the transition will vastly reduced the peak force. The angle and composition of the slope will determine your outcome. Soft spring snow is probably best. Powder snow would have a much lower impact force, but most like you'll become deeply embedded and suffocate. Grass, shrubs or loose soil would be the next choice. If it's rocky or trees terrain you're probably toast
What do you mean by transition? Like where the snow meets the mountain?
I think he means transition between vertical and sloped/horizontal surface. Targeting such a landing area would be pretty hard.
No, I just mean any slope really. In action sport, you call this "catching a transition". Landing on a slope vastly reduces your impact by spreading it out of a longer period of time
I feel like it's missing the whole question of what to do if you'll be hitting water instead of dirt, trees or snow. I've heard speculation that you could improve your odds of surviving by e.g. throwing down a pair of keys or similar to break the surface tension right before you hit the water, but I'd like to see that investigated further.
Also, no matter the landing zone, it seems like you should try to minimize your landing speed by maximizing drag until the last moment, then switch to a position from which to execute a five-point-landing (or going through the water surface with feet first) - I'd be interested in strategies for how to successfully execute that.
Also, no matter the landing zone, it seems like you should try to minimize your landing speed by maximizing drag until the last moment, then switch to a position from which to execute a five-point-landing (or going through the water surface with feet first) - I'd be interested in strategies for how to successfully execute that.
> I've heard speculation that you could improve your odds of surviving by e.g. throwing down a pair of keys or similar to break the surface tension right before you hit the water, but I'd like to see that investigated further.
Mythbusters did it, it didn't help.
https://mythresults.com/episode5
Mythbusters did it, it didn't help.
https://mythresults.com/episode5
The harm from impacting water is mostly due to the bulk of water which is in your way, which is neither very compressible, nor can able to instantaneously displace itself so that it is out of your way.
It is not from the 0.07275 joules per square metre of surface tension.
It is not from the 0.07275 joules per square metre of surface tension.
There’s a pretty good chance your keys would just float up past you if you tried to throw them, and hit the water long after you. I think humans have a higher weight to surface area ratio.
But if you found a waterfall, you might try to land in the area that’s bubbling up. That could conceivably improve your chances when hitting water, which are very slim - hitting water in free fall is not that much better than hitting concrete.
Trying to execute a stand-up 2 or 3 seconds before impact might help you survive, I could buy that. I’d guess this is something that’s difficult to do without having tried it before, it usually takes a few tries to do without flopping back to flat.
But if you found a waterfall, you might try to land in the area that’s bubbling up. That could conceivably improve your chances when hitting water, which are very slim - hitting water in free fall is not that much better than hitting concrete.
Trying to execute a stand-up 2 or 3 seconds before impact might help you survive, I could buy that. I’d guess this is something that’s difficult to do without having tried it before, it usually takes a few tries to do without flopping back to flat.
Would changing your orientation even matter? Wouldn't you just reach the new terminal velocity by the time you entered? It's not like your a Starship that can flip at the last moment and has a big difference between sideways and vertical terminal velocity.
I think orientation does matter, and that a water entry might be more survivable with a vertical entry. Think about diving from a high-dive versus a belly flop. At terminal, you’re still likely to break legs or die from entry in a vertical position, but the surface area hitting the water is a lot less if you’re feet first, plus you’d have shoes on, etc. Check out the world record cliff jump https://www.dailymotion.com/video/x32e3od
Terminal in stand-up is indeed much higher than terminal in the flat position. A perfect stand-up / head-down is around 180mph typically, while flat is around 120mph, give or take depending on body shape & density. But it takes time to accelerate, long enough that I think if you stood up quickly you’d still be around the flat-position velocity. The maximum you can theoretically accelerate is about 22 mph/s, but you’re starting from terminal with tons of drag, so I think it would take 5-10 seconds to reach 180mph, and you can go from flat to stand-up in 1-2 seconds.
Terminal in stand-up is indeed much higher than terminal in the flat position. A perfect stand-up / head-down is around 180mph typically, while flat is around 120mph, give or take depending on body shape & density. But it takes time to accelerate, long enough that I think if you stood up quickly you’d still be around the flat-position velocity. The maximum you can theoretically accelerate is about 22 mph/s, but you’re starting from terminal with tons of drag, so I think it would take 5-10 seconds to reach 180mph, and you can go from flat to stand-up in 1-2 seconds.
Water landings you want to go in feet first but not perfectly vertical. Walking away is possible if your angle of entry is perfect--but even then you might be knocked unconscious and even if you're not you might not make it back to the surface before you run out of air.
This made me remember a Myth Busters episode where they were testing if Indiana Jones could survive a fall from a tall building into an awning (happens in one of the movies). They were pretty sure that it was impossible, but the crash dummy survived with a bruised rib :)
The life raft was also possible, but it has to be a giant one.
So did anyone test the nuke and the fridge?
Reel Physics concluded from frame analysis that is possible [1].
https://youtu.be/foUn_6W9N-Y
https://youtu.be/foUn_6W9N-Y
I guess we all owe George Lucas an apology for that one.
Not the fridge specifically, but there's the famous case of the (apocryphally) fastest man made object, which is supposedly a large manhole cover that was blasted into space by an underground nuclear test detonated in a shaft 150m below it: https://www.zmescience.com/science/news-science/fastest-manm...
Now obviously the shaft here functioned nearly like a gun barrel so the manhole cover could've reached 5-6x the escape velocity (according to the scientists), but even just being accelerated to 10% of escape velocity in the span of milliseconds would've turned the hapless Mr. Jones into a fine red paste. Assuming he resided in a metal fridge at the time, he would've become what can only be described as a flat tin can of pâté.
Now obviously the shaft here functioned nearly like a gun barrel so the manhole cover could've reached 5-6x the escape velocity (according to the scientists), but even just being accelerated to 10% of escape velocity in the span of milliseconds would've turned the hapless Mr. Jones into a fine red paste. Assuming he resided in a metal fridge at the time, he would've become what can only be described as a flat tin can of pâté.
Hang on, wouldn't this make that manhole cover also the furthest manmade object from Earth? Voyager 1, even after all of its slingshots, is traveling at about 38k mph. That manhole cover is traveling several times faster, and was launched decades before Voyager even thought about taking off.
Edit: And before anyone mentions the fact that Brownlee's calculation did not take into consideration atmospheric forces (which probably disintegrated the cap before it got to space), at least some molecules of the cap probably did go that far, and would still remain the fastest, and possibly furthest object from Earth (assuming it did not get caught in the gravity well of another object on its way out).
Edit: And before anyone mentions the fact that Brownlee's calculation did not take into consideration atmospheric forces (which probably disintegrated the cap before it got to space), at least some molecules of the cap probably did go that far, and would still remain the fastest, and possibly furthest object from Earth (assuming it did not get caught in the gravity well of another object on its way out).
You are probably right. Although I'd assume that given the cover was very close to the epicenter of the detonation, it would've been almost instantly vaporized and turned into plasma even before air resistance would've done the job.
The manhole cover *did* survive the detonation--it's visible one *one* frame of film. Unfortunately, only one so there's no way to figure out it's velocity. All they can conclude is a minimum velocity based on the fact that it's not on two frames.
There have been objects placed even closer to nukes that have survived and note Project Orion--not only objects near a bomb, but the plan was to put a crew near bombs. Obviously, they would catch some radiation but that's going to happen anyway in deep space flight and back then they didn't realize the cancer risk.
The basic physics of protecting the ship and crew from the nearby detonations is clear. There is some question about whether it could actually be used to take off from Earth, though--it's not so certain if the pusher plate could be kept cool enough during the ride to orbit. Deep space doesn't require such sustained thrust, it's no problem. EMP from near-Earth detonations is a big issue, though.
There have been objects placed even closer to nukes that have survived and note Project Orion--not only objects near a bomb, but the plan was to put a crew near bombs. Obviously, they would catch some radiation but that's going to happen anyway in deep space flight and back then they didn't realize the cancer risk.
The basic physics of protecting the ship and crew from the nearby detonations is clear. There is some question about whether it could actually be used to take off from Earth, though--it's not so certain if the pusher plate could be kept cool enough during the ride to orbit. Deep space doesn't require such sustained thrust, it's no problem. EMP from near-Earth detonations is a big issue, though.
Why would any molecules make it out of the atmosphere? The mean free path at low altitude is very short.
Not to detract from another great "What If?" article, but I think the biggest gotcha is right at the beginning:
> Let's say your jet blows apart at 35,000 feet. You exit the aircraft, and you begin to descend independently.
As far as I know, most airplanes don't do that nowadays. They tend to descend more or less in one piece (or several big pieces) to ground level and "blow apart" there. If they do blow apart at high altitude, it's probably due to an explosion which is apt to drastically reduce the chances of passengers being conscious (or alive) during the free-fall phase.
> Let's say your jet blows apart at 35,000 feet. You exit the aircraft, and you begin to descend independently.
As far as I know, most airplanes don't do that nowadays. They tend to descend more or less in one piece (or several big pieces) to ground level and "blow apart" there. If they do blow apart at high altitude, it's probably due to an explosion which is apt to drastically reduce the chances of passengers being conscious (or alive) during the free-fall phase.
Terrorist bombs normally do not actually blow up planes. Rather, a successful bombing damages the skin enough that the wind shreds the plane. Thus it's quite possible to survive the bombing. Surviving the plane disintegrating around you, though...
Why on earth does such a simple text-only page not have “Reader View” on iOS safari!?
Probably because each paragraph is a table row :D
Oh the sweet 90s and early 2000s :-)
Oh god, I hoped you were kidding. But you were not ...
> Let's say your jet blows apart at 35,000 feet. You exit the aircraft, and you begin to descend independently. Now what? First of all, you're starting off a full mile higher than Everest, so after a few gulps of disappointing air you're going to black out.
Not mentioned is the fact that at 35k feet, the average temp is around -40 to -55 degrees Celsius. I don’t know if it would kill you, but you’d probably freeze some skin, and if you try to look you might freeze your eyeballs. It will be hard to move muscles after sixty seconds of 120mph freezing wind.
I’m curious if the passing out part is true. It certainly might be. My experience skydiving is that I would get light headed and seeing stars at 18k feet unpressurized, and the instant I jumped out of the plane, everything got better. Seemed like the force of the air in my face somehow packed all the oxygen I needed. 35k is very different from 18k, obviously.
* Oh yeah, and speaking from experience, I know it’s hard to see straight without wearing goggles when in free fall. I forgot to put them on once before jumping. Never forgot again after that.
Not mentioned is the fact that at 35k feet, the average temp is around -40 to -55 degrees Celsius. I don’t know if it would kill you, but you’d probably freeze some skin, and if you try to look you might freeze your eyeballs. It will be hard to move muscles after sixty seconds of 120mph freezing wind.
I’m curious if the passing out part is true. It certainly might be. My experience skydiving is that I would get light headed and seeing stars at 18k feet unpressurized, and the instant I jumped out of the plane, everything got better. Seemed like the force of the air in my face somehow packed all the oxygen I needed. 35k is very different from 18k, obviously.
* Oh yeah, and speaking from experience, I know it’s hard to see straight without wearing goggles when in free fall. I forgot to put them on once before jumping. Never forgot again after that.
>I don’t know if it would kill you, but you’d probably freeze some skin, and if you try to look you might freeze your eyeballs. It will be hard to move muscles after sixty seconds of 120mph freezing wind.
https://youtu.be/6SI2V_DbCTw
If you haven't seen it, watch it from beginning.
https://youtu.be/6SI2V_DbCTw
If you haven't seen it, watch it from beginning.
Thanks, what a crazy story! I started it, and they mention this incident happened at 17k feet, so isn’t subject to the kind of freezing temps you’d see at cruising altitude, right? People skydive from 18k feet all the time. Haven’t finished yet because it’s long, but does it say something later about surviving cold at higher altitudes? (Edit I did hear now that it was -17C at the start before they dove lower… wild!!)
https://www.skybrary.aero/index.php/Time_of_Useful_Conscious...
You have 30-60 seconds at 35k. At 18k you'll feel it but you'll be down long before it's serious. (Although if it was unpressurized for the climb I wonder how much of the time you used up that way.)
Real world data--a guy punched at such altitudes and lost his oxygen in the process. Blacked out, came to on the way down. Amazing survival--he was supersonic at the time and punched without blowing the canopy.
You have 30-60 seconds at 35k. At 18k you'll feel it but you'll be down long before it's serious. (Although if it was unpressurized for the climb I wonder how much of the time you used up that way.)
Real world data--a guy punched at such altitudes and lost his oxygen in the process. Blacked out, came to on the way down. Amazing survival--he was supersonic at the time and punched without blowing the canopy.
> As you go down 15,000 feet, you can also go sideways two-thirds of that distance—that's two miles! Choose your landing zone. You be the boss.
Pretty interesting. I wouldn't have imagined you could do this.
Pretty interesting. I wouldn't have imagined you could do this.
Probably depends on whether you are in boxers or in a speedo.
Tracking [0] is frequently used by skydivers after close freefall formation manoeuvring ('relative work') to increase their horizontal separation before deploying their canopies.
https://en.wikipedia.org/wiki/Tracking_(skydiving)
https://en.wikipedia.org/wiki/Tracking_(skydiving)
Good summary. It left out the benefits of always wearing a Mjolnir Mark VI power armor with an active microfusion core; the hydrostatic gel layer and surface-range energy shielding can protect the wearer from phenomenal kinetic impacts, while the armor-lock system guards the joints and other sensitive anatomic structure from contusion or rupture. Plus, the built-in transponder will minimize the time for emergency first-response / evac forces to locate the crash site and assist in resuscitation and vertical recalibration (always oddly necessary in those suits; I don't know why they don't just put some glue on that vertical toggle switch to keep it from flipping so often).
Don't leave home without it.
Don't leave home without it.
The worlds smallest parachute is 3.25m square [0]
This is only possible because it's behaving like a wing and generating lift if you look at the shape closely... probably out of luck to find a piece of debris that is going to behave like an airfoil well enough, but this parachute user can land with zero injuries, if you only want to survive, perhaps some concessions can be made, and this made me wonder:
If you found such a flat and light enough piece of material with a useful surface area - how best to use it? even if it's not the right shape to generate significant lift, there are different ways to use it, and one of them causes the smallest terminal velocity - the obvious use is directly against the airflow like a flat parachute - but would it work better if you tried to convert your downward force into a horizontal one by deflecting the air into one direction? (like a really bad glider, or those wingman suits). My instinct says yes, but without lift I can't explain why, I suppose because I can see where the force is going (horizontal) rather than just "dissipating" through turbulence.
I suppose at the minimum, by directing the flow to one side you provide yourself with significantly more horizontal mobility for choice of landing site.
https://www.guinnessworldrecords.com/world-records/88729-sma...
This is only possible because it's behaving like a wing and generating lift if you look at the shape closely... probably out of luck to find a piece of debris that is going to behave like an airfoil well enough, but this parachute user can land with zero injuries, if you only want to survive, perhaps some concessions can be made, and this made me wonder:
If you found such a flat and light enough piece of material with a useful surface area - how best to use it? even if it's not the right shape to generate significant lift, there are different ways to use it, and one of them causes the smallest terminal velocity - the obvious use is directly against the airflow like a flat parachute - but would it work better if you tried to convert your downward force into a horizontal one by deflecting the air into one direction? (like a really bad glider, or those wingman suits). My instinct says yes, but without lift I can't explain why, I suppose because I can see where the force is going (horizontal) rather than just "dissipating" through turbulence.
I suppose at the minimum, by directing the flow to one side you provide yourself with significantly more horizontal mobility for choice of landing site.
https://www.guinnessworldrecords.com/world-records/88729-sma...
The usefulness is questionable, but it still is an entertaining read.
Make sure you bookmark it so you can consult it at 15,000:feet!
done! Is there a way to put an auto reminder to read it just a minute before the accident happens?
Setting up some trigger to open the page based on your phone's accelerometer would probably work.
IFTTT?
And mark it for Offline Reading, since your reception will be pretty poor until you’re closer to the ground.
Best to store it in GNU Info format.
https://xkcd.com/912/
https://xkcd.com/912/
And you'll be reading it for the rest of your life.
I'm reminded of the story of the girl who survived, somehow, a fall from a plane in the Amazon while strapped in to her seat. The theory is that the row seats spun like one of those seed pods and slowed her down when hitting some trees.
https://www.nytimes.com/2021/06/18/science/koepcke-diller-pa...
I've often thought about this topic since the explosive decompression of Malaysia flight 17 over Ukraine. The anti-aircraft missile apparently caused an instant, explosive decompression of the plane. Assuming you weren't hit by one of the projectiles, you would have found yourself suddenly free-falling.
https://www.nytimes.com/2021/06/18/science/koepcke-diller-pa...
I've often thought about this topic since the explosive decompression of Malaysia flight 17 over Ukraine. The anti-aircraft missile apparently caused an instant, explosive decompression of the plane. Assuming you weren't hit by one of the projectiles, you would have found yourself suddenly free-falling.
I don't even think it would matter if it spun. She went into trees. Lighter tree branches are about your ideal landing.
There is one case of a guy who apparently hit a pine tree perfectly, then a snow bank *and walked away*, with no injuries that were obviously from the landing. No aiming or anything, pure luck. (The injury situation is uncertain because he was injured when he jumped and hadn't had time to take stock of his injuries.)
There is one case of a guy who apparently hit a pine tree perfectly, then a snow bank *and walked away*, with no injuries that were obviously from the landing. No aiming or anything, pure luck. (The injury situation is uncertain because he was injured when he jumped and hadn't had time to take stock of his injuries.)
Quite morbid for a Do It Yourself guide ;-)
Fun fact, Vesna [0] from Serbia came down in Srbská (Serbian) Kamenice a small village in Czechoslowakia. What a coincidence. Btw. there was an article about this incident just this year [1] with some pictures.
[0] https://en.wikipedia.org/wiki/Vesna_Vulovi%C4%87
[1] https://zpravy.aktualne.cz/pred-49-lety-roky-teroristicky-ut...
Fun fact, Vesna [0] from Serbia came down in Srbská (Serbian) Kamenice a small village in Czechoslowakia. What a coincidence. Btw. there was an article about this incident just this year [1] with some pictures.
[0] https://en.wikipedia.org/wiki/Vesna_Vulovi%C4%87
[1] https://zpravy.aktualne.cz/pred-49-lety-roky-teroristicky-ut...
I wonder why the advice if you're still on a row of seats is to ditch it. Whilst heavier, it may also be wider. I guess it's the ratio of mass to surface area (× drag coefficient) that matters, and if the thing you're attached to's mass-to-surface-area ratio is lower, you should keep holding onto it.
As long as holding onto it doesn't result in you orienting your body away from presenting the most area to the oncoming air. Don't hold onto a beach ball for example.
As long as holding onto it doesn't result in you orienting your body away from presenting the most area to the oncoming air. Don't hold onto a beach ball for example.
I don’t see any advice as to that. FTA:
“If thus connected, you have some questions to address. Is your new conveyance air-worthy? […] If you choose to go it alone”
Also, even if it is dropping faster, it may be worth it to stay in your seat if you can use it as a crumple zone
“If thus connected, you have some questions to address. Is your new conveyance air-worthy? […] If you choose to go it alone”
Also, even if it is dropping faster, it may be worth it to stay in your seat if you can use it as a crumple zone
> Whilst heavier, it may also be wider
Weight/mass doesn't matter, as all objects of the same shape above a certain density fall with the same speed. So literally just pick the widest object you can find, no matter how heavy it is, and ride it.
Weight/mass doesn't matter, as all objects of the same shape above a certain density fall with the same speed. So literally just pick the widest object you can find, no matter how heavy it is, and ride it.
You want something that will act as a crumple zone and slow your final crash. So seats would be better than a wide sheet of iron of the same mass. At the last moment (and not before) stand on the seat and follow the roll the crash up your body advice.
Yes, but the GP was talking about drag, so I responded to that.
That's not how that works at all.
Terminal velocity occurs when the drag force balances the gravitational force. So F_d = F_g
F_d is proportional to the area of the object and the velocity squared.
F_g is proportional to the mass.
So, for constant area, at terminal velocity we have v^2 ~ m or v ~ m^(1/2) where "~" denotes a proportional relation.
Thus a heavier object falls at a higher terminal velocity than a lighter one.
Terminal velocity occurs when the drag force balances the gravitational force. So F_d = F_g
F_d is proportional to the area of the object and the velocity squared.
F_g is proportional to the mass.
So, for constant area, at terminal velocity we have v^2 ~ m or v ~ m^(1/2) where "~" denotes a proportional relation.
Thus a heavier object falls at a higher terminal velocity than a lighter one.
Ah, you are right, I was thinking acceleration.
Given a constant shape and density, terminal velocity goes up proportionally to the square root of the length of the object. Unless the object your grabbing is noticeably less dense than you are, which I'd guess wouldn't be true for the seat row, you're better off separated.
If by some chance the row of seats is not spinning wildly and is just falling in it's normal (pre-accident) orientation then you should see if you're butt is being pressed into the seat or if you are lifting up constrained only by your seatbelt. Butt into seat, stay. Constrained by seatbelt, unlatch.
Note that your terminal velocity is not an intrinsic property, but a consequence of air resistance on your body - air resistance you will not be feeling when enveloped by a row of airline seats. Even if the seat row has a higher terminal velocity than you would by yourself, its wake will take you with it.
Which isn't to say you won't feel your seatbelt tugging on you. You will likely be straining painfully against it. But that's because you'll be tumbling wildly, the entire assembly battered and buffeted by huge forces.
Which isn't to say you won't feel your seatbelt tugging on you. You will likely be straining painfully against it. But that's because you'll be tumbling wildly, the entire assembly battered and buffeted by huge forces.
Why unstrap? Having the seat underneath you gives you a bit of crumple and some protection from landing on something sticking up. In her case I suspect it had a lot to do with her survival--since she came down in rainforest I suspect the seat hit a lot of branches.
Naively I would assume that one risk might be the seat itself causing you damage upon impact. At those speeds could there be a risk of the entire seat coming apart on impact and impaling you with metal shards?
This article isn't meant to be serious, I don't think.
Juliane Koepcke, one of the only people to survive such a fall, did it strapped into a row of seats. And when she landed she was in good enough shape to survive 11 days in the Amazon rainforest (!!!) and make her own way to safety. So I'd say statistically, it's about the best thing you can do.
https://en.wikipedia.org/wiki/Juliane_Koepcke
Juliane Koepcke, one of the only people to survive such a fall, did it strapped into a row of seats. And when she landed she was in good enough shape to survive 11 days in the Amazon rainforest (!!!) and make her own way to safety. So I'd say statistically, it's about the best thing you can do.
https://en.wikipedia.org/wiki/Juliane_Koepcke
In summary few things you can do to increase the odds of surviving.
I can't help but feeling panic and hopeless if I were in that situation because THERE'S NO UNDO BUTTON / CANT SAVE-AND-RELOAD, you have to do it right at first attempt! Can slide to forest? Whoops I just missed it.
I can't help but feeling panic and hopeless if I were in that situation because THERE'S NO UNDO BUTTON / CANT SAVE-AND-RELOAD, you have to do it right at first attempt! Can slide to forest? Whoops I just missed it.
Reminds me of this: https://youtu.be/oZIzreiseMk
I'm not sure if their analysis is accurate, but it's sure fun to watch :)
I'm not sure if their analysis is accurate, but it's sure fun to watch :)
A very entertaining video about the subject: https://www.youtube.com/watch?v=dy5xLVx2NGY
Seriously, this reminds me of a question I have always being afraid to ask due to morality reasons. Was there any chance for the 911 jumpers to survive in any way, no matter how minimal?
Hard surface landing--nope, nobody has ever survived free fall into something hard. No survival unless they could rig some sort of parachute.
"If you go parachuting,
and your parachute doesn’t open,
and you friends are all watching you fall,
I think a funny gag would be to pretend you were swimming."
Deep Thoughts by Jack Handey
Deep Thoughts by Jack Handey
Stephen passed away January 2021 from COVID (but had an amazing 85-year life) and I was just reading his diary from the incident. The gist:
There was still an hour left before an emergency landing at SFO. The cabin was festering with vomit and tears, but there was a profound sense of love and connectedness and compassion among every passenger. Every one felt touched by a Divine Grace.
However, after a only few hours at the terminal and people could finally leave, it was every person for themselves as they physically and verbally harassed each over to get to where they were going. So quickly back to being selfish humans...
My Mom said she would drive from Los Angeles to get him, but he said that if he didn't get on a plane right then, he would never be able to fly again. So he courageously flew SFO->LAX right away, one of many flights he would continue to take throughout his life.
[1] https://en.wikipedia.org/wiki/China_Airlines_Flight_006