Bản chép lời đầy đủ của SYSK Selects: How Black Boxes Work

you could find them. But they think that they were called black boxes originally because either the original ones were black or because it was kind of a grim moniker because the boxes will become charred in the wreckage and turn black. Yeah, I saw another explanation to that. I don't think holds water. That they were initially like round and red and uh, when they first debuted it, someone in the room said, oh, what a nice black box, as a smarmie thing to say. I guess about something that's round and red. I don't know if that holds water though. Yeah. It's weird all around. And apparently in the aviation industry they don't call them black boxes anyway. That's like something for the news media and jerks like us, they probably call them crash survivalbal memory units. I think what they column is either one of the two things that are either a flight data recorder or a voice box. Well, there's a there's a lot of um. Yeah, it's not that hard. But because of the media and in part because of this article, uh, it's very unclear that black boxes are different things. Yeah, there's two different we'll get into it, but there's really two different kinds. And what you would think of as a black box is actually a group of components the system that yeah, that formed this system that's meant to record the flight data and the cockpit um sounds, which is the discussion and the beeps and the pings and all that of every single flight that goes into the air commercial flight. Yeah, um, in order, and then it is housed in a way that it will survive. I've even a horrible plane crash. It's frequently the only survivor of a plane crash. Yeah. And we'll get to the testing of these which I thought was kind of the coolest part later. Yeah, I thought so too. And the whole point is, of course, is to get all the data to figure out what happened in a plane crash, what happened, because very frequently that it's not. Again, if it's the sole survivor, then there's no one there to say, oh, well there's fire. There's fire. It's somebody lit a fire in the cabin and and the whole the plane blew up. Yeah, but you could hit play and you're the pilots going someone lit a fire in the cabin, right, and there you have it. Yeah, but it's a little more complicated than that. Uh. And goes back to UH. In the nineteen forties, there was a Finish aviation engineer named V. A. Ho which doesn't sound finish, um the immigration and he did some of the first UM flight recording was something called the Mata Harre for World War two planes test flights basically, but I think it was only like instrument readings at the time. It wasn't recording uh uh, any voices like cockpit recording. Well, supposedly the right brothers had some sort of recording device to record the propeller rotation. That's pretty cool. Yeah, it's like there's been flight data ever since there's been flight that's awesome. I found that an Australian named David Warren was the one who really came up with the black box recorder. Yeah,

he's the one that brought the voices into it, the actual audio recording. Okay, yeah, yeah, he was. He was a member of a crash investigation for a mysterious plane crash and he thought it would be really good if we had like a recording of what was going on at the time. So he developed him. Yeah, he's like that, you couldn't be too hard. And that was the fifties I believe, and they became widespread and mandated in the sixties. Yeah, in Australia. It was the first country and I guess even continent to make the mandatory. So go uh ozzy uzzy AZZI good on you. So um. Initially the the black box recorders were UM recording on magnetic tape, and then they moved in the strangely enough, in the late nineties early two thousands. It wasn't until UMO eight that they fully switched. Yeah, that the f a A mandated in two thousand five. There was a list of proposed rules, and one of them was, let's get rid of magnetic recorders, which no one uses anymore. That's two thousand five after all, and go to solid state digital recorders. Yeah right, uh, no cassettes even um and uh they the f A thought about it and thought about and thought about and finally said, okay, fine, we'll do that. One of the big reasons why was with magnetic tapes you could just record the last half hour of a cockpit conversation. Yeah, it would. It would rerecord over itself every thirty minutes, which is you know, probably that's all you need. Yeah, you want to hope that your plane doesn't take thirty minutes to go down be pretty bad. Um. But the the big superiority that solid state has over that is that the recording time is far greater. Yeah, the recording media is smaller, more durable. Yeah. If you're moving parts yeah, and so it can't break down as easily. And if one part breaks you can still take the solid state memory sticks and reconfigure them and get the data off of them. Still. Yeah. They cost between ten and fifteen grand each and are usually um comes straight from the manufacturer, like they work with the airline manufact airplane manufacturers themselves to like preinstall them on these planes. Right, Yeah, so you have a black box manufacturer who sells them to the airlines, who are the airplane manufacturers who sell the airplanes to the airlines. With the black boxes are installed, it's like a part of the plane, that's right. Um, so we should probably explain this now it's been long enough. A black box can be one of two things, well, one of three things really, Um. It can be the flight data recorder, or it can be the cockpit voice recorder, that's right, Or it can be the crash survivable memory unit. Black box refers to all three of those. Yeah, the important thing, the only thing that really needs to survive the crash is the crash survival memory. That's where the data is sent and housed. And um, that's the one that's super super beefed up to survive like a nuclear war. Basically, so on any flight, on any commercial flight, you have hundreds, if not thousands of sensors going on at all times, and they are measuring things like airspeed, altitude, uh, cabin pressure, cabin temperature, UM, wing trim everything, what are your flaps doing? Yaw? Yeah, you don't just guess at yaw, you gotta measure right, right, right, And so all of this information is coming into the flight computer and plugged into the flight computer is uh, well, basically it's like an upstream passive eavesdropping unit. It's called the flight Data Acquisition unit, and it takes all of this UM. That's up front, right, that's upfront with the pilots, UM. And it takes all of this incoming information and it records it. So not only is the are the pilots and the the ground control getting all this information, but it's being recorded as well, UM, and it's being routed to the recorders through the Flight Data Acquisition unit. Right. So also up front in the cockpit you're gonna have at least four microphones and in some newer planes also video cameras. Yeah. That's the newest, the latest grade, right yeah, which you can't do that on magnetic tape. You know what I'm saying. Yeah, they have to start drinking vodka instead of like brown liquors. What do you mean the pilots, you know, like it's water. I'm just having some h duo. That's not the Great Goose or Yeah, I'm joking. Okay, although pilots have been known to drink here and there and they get in trouble. Yeah, they should get in big trouble for they should. You're the d D Okay, if you're an airline pilot, there's no way around it. Yeah, the only you shouldn't do is drink and do drugs. So um up there to eavesdrop on the pilots, and not just the pilots, but also all the sounds going on in the cockpit. Are these microphones and they're recording everything through the cockpit voice recorder. Yeah, and you talked about the sounds. That's a big deal. Like not only do you want to hear Captain Jim say, holy crap, our wing is on fire, but they want to hear thirty seconds before that if they hear just some weird noise and they're trained to pick up all that ambiance sound and experts or trained too to listen out for things that you would probably never notice. Is just a regular dude, right exactly. And they can sit there and hear a ping or a thud or a knock or a combination of those things and be like, oh, I know what happened. Somebody smoked in the laboratory and kept while they were on Their cell phone is loaded, and so you've got again, you've got the cockpit voice recorder, you've got the flight data recorder, and all of that info going out to those two guys is going through the flight data acquisition unit, and it's sending the info all the way to the back of the plane, where the cockpit voice recorder and the flight data recorder are located. And why is it located in the back, because the front of the plane takes up most of the force of the impact, and it's far likelier that something placed at the rear of the plane, specifically like the tail cone or the aft galley ceiling or something way in the

back, is going to be likelier to survive because the rest gets mushed. Yeah, we talked about that in our Surviving a Plane Crash episode. And while they won't come out and say it out right. It is a little bit safer in the back of an airplane because you usually go nose down, and by all accounts, if you drive a plane into a mountain, the captain and the co pilot are going to suffer the worst of it. Maybe if you're in the back bathroom having your cigarette, you're shaving like on airplane, you might have a chance to survive. Started like cutting itself. Uh and speaking of mountains, chuck, this is good at places any to put it. There's some something called plane crash info dot com slash last words, and there's a lot of It's not just this site. There's a lot of sites that have um recordings from black boxes, no thanks from like the last seconds or whatever. And this site also has just like transcription to the last couple sentences, and one of them was mountains the last thing. But then there's been there's other ones to like, um Ma, I love you was one the last words of one pilot. Another one was Pete sorry, so I get somebody screwed up. Another one was hang on, what the hell is this? Yeah? And then other ones seem like they don't realize what's about to happen. This isn't as bad as I thought it would be, right, Yeah, yeah, yeah, but it's pretty interesting stuff. Some of it's pretty grim, some of it's super sad. Yeah, it's like not an uplifting things on a read on a Friday afternoon. Oh No, it's not uplifting, but it's it's definitely interesting. Yeah. I would not recommend reading that before you take a flight. No. As a matter of fact, Umi was traveling UM recently while I was researching this and I met you send it to her. I was like, I can't send her this. She's got a fly back here. That's awful. UM. Alright, so we talked, Uh, let's go ahead and talk about the flight the flight data recorder. UM. You mentioned that they're all kinds of um of data being recorded, Like up to seven hundred types of data can be recorded. UM. Like they can tell when you just turn a switch on, that's like it's logged all of a sudden, captain turned on, even interior cabin light switch, you know, that's all recorded. And UM. The f a A they require pre two thousand two planes to have a minimum of eleven and twenty nine parameters. If it was built after two thousand to um at least eight eight parameters, right, I don't see why they just don't log at all if they can. Well, apparently like that that rule that forced up to eighty eight parameters be recorded like cost the airline industry like three million bucks or something. And that's the reason they're notoriously tight. So that's why they keep fighting it. And it's the NTSB that's saying like, let's push this along. It's two thousand five, we need to stop using magnetic reel reel right, And the f a A is like, I don't know, Well, the f A is being post around by the airline industry. Well scary enough, um, I guess it's

a good time to mention this. There was something called the Safe Act, Safe as Asian and Flight Enhancement Act, and it's been up twice and has not passed this legislation either time. And all they're trying to do is provide a second recorder and one of them should be deployable in the rear, which makes sense, like if the plane hits an impact, this thing pops off the back of the plane altogether and little costs. Like I guess so because because they said, uh, the f A A has a long history of delaying uh much needed upgrades and this equipment, and I guess it's because of price or the airplane lobby. Yeah. When you when your federal agency is actually like a safeguard to protect the finances of the industry, is regulating, that's not good. No, it's not Why can't everybody just do things right? I know it's frustrating, and money is typically at the root of it all, you know, it always is. Yeah, all right, So we talked a little bit about the testing. I guess we should just talk about what these things are built out of, why they survive that the c S m U back in and Roswell New Mexico. No, but there are three layers of materials to keep these things safe. Um, you got your aluminium housing on the outside of it, and it holds all your memory cards. No, the aluminum is inside. Oh yeah yeah, yeah, yeah, Okay, that makes sense. It's the weakest link, you know what I mean, it's on the inside surrounding it's the last stand of protection. I guess, right, that is, like you said, it's holding the memory cards, which are the one thing you really want to survive, the only thing. Yeah, and the people. This is right, right, Yeah, I guess it's a good point. And this is the crash Survivable memory unit, which is actually a part of the flight data recorder and the cockpit voice for quorder. Yeah, but it's also this separate it's kind of like the Holy See, you know, the Holy of Holies, the Temple within the Temple of Jerusalem. Yeah, like everything else will get mangled and it doesn't matter. But all you need it, like you said, are those memory cards, right, Okay, so so go ahead. There's an aluminum housing around the memory cards, right, and then around that you have it insulated with a dry silica one inch of it. And that is because a lot of times when planes crash, they catch on fire. Yeah, you want to retard fire. Put a niche of silicus stuff around this, around whatever you want, your hand, your head, sure, just do it. You won't get burned. H And then around that is your outer shell. And it's either stainless steel or titanium. It's about a quarter inch thick. And that's like you know that you're bomb casing and all of that is why you can't build a plane out of all this. It would be too heavy. Yeah, And so this this one to three punch of a crash survival memory unit. Um, it's a cylinder. Did you say that? I thought it was implicit. It's just so imagine like a steel box. And you can also go on to how stuff works and type in um, how black boxes working. It'll bring up

images. But imagine like a steel box that forms like an L on its back right, so the foot is sticking upward into the air. And then on the part that's along the ground now of the L is it's cylinder that's coming up. Looks like it's it's holding some oil or something like. That's an oil cylinder. It's like a fat squat barrel. Then attached to that is this little tube another cylinder but longer and shorter that serves as the handle for the whole unit. But it's also a beacon. Yeah, and that's super important. Um. And actually we'll get into that. But you gotta find these things, you know, it does no good if it's hidden behind a tree or at the bottom of the ocean. They like to hide, they do. So we talked about some of the testing that these things go through and it's pretty awesome. Um, they do one, two, three, four, five, six tests, the first of which is just a basic crash impact. They shoot it out of an air cannon at thirty four hundred g s into an aluminum honeycomb and it smashes it with a force equal to times its own weight. It's just like, I want to see this thing in super SloMo basically, which not only does this simulate the impact of a major plane crash, it actually probably overstates the force. I think they overstayed everything. Yeah, you know, and these things survived. They say, okay, good, alright, let's take it on to the next test, and the flight data recorders like wait what yeah, exactly, And they take it onto the pin drop, which I think it's funny that they call it the pin drop. Has nothing to do with it sound, it's like engineering humor. Yeah. But they take like a five pound weight with a quarter inch the old pin coming out of the end of it. It's like a little spike, and they drop it from ten ft the spike onto the weakest axis of the uh, the black box. It's like a puncture test. Yeah, and it nothing happens, so they move it on to the next test. Yeah, the static crush, which would be a good band name uh, five minutes of five thousand pounds per square rich pressure applied to the six major access points. So it's just a constant, not an impact thing. But just let me see if I can just crush you over time with brute force. Yeah. It's like a headlock. Yeah, the worst headlock you can ever imagine. And then the fire test, which they fire a propane fireball with three burners at about two thousand degrees fahrenheit for an hour and just let it sit there and see if it melts or does anything yeah, or explodes or whatever. Yeah, it just sits there. Um. And then the planes frequently go down. Well, when they go down, they frequently go down out into the ocean or the sea. So your black box has to survive underwater. So they do a deep sea immersion test um, which is like a pressurized tank of water for twenty four hours. Uh. And then they also do a saltwater submersion test, so this thing has to basically sit around in saltwater for thirty days, that's right. And finally they will let it soak in other types of fluids like jet fuel and lubricant and fire extinguisher chemicals and anything else in a plane that it might end up submerged in. And if it can withstand sitting in jet fuel for a period of time, then you're good to go. Yeah. And then after all this they put a little um mortarboard on the the cylinder and send it along its way to be installed in an airplane. That's right where it's sadly, will only be used if something really bad happens. All right, so your plane is crashed. Yeah, we're both dead, right, but the black box has survived, it lives on what happens to it, Well, they have to find it first, um. And like we said, these things are tested to make sure that they can withstand deep sea and salt water immersion, which they sometimes have to UM And in the event that they are going to go into the water, the little handle that has an underwater beacon installed in it actually has this water detector and when water comes in contact with the beacon, it starts to set it off and it sends out a pink I think every minute or thirty seconds for the next thirty days or something like. Yeah, it's one per second for a yeah, um. And this ping you couldn't hear it if you were listening for it. But if you were listening through sonar, you would be able to pick it up. And the beacon sends out the ping and the people go find the ping and they get it. They can transmit ideally, but it can transmit up to fourteen thousand feet, which is pretty impressive, right, um. And and if you can find the beacon thanks to the ping, that's awesome. There have been cases where the black boxes have been found long after the ping stopped. Um Air France flight four four seven when I think two thousand nine and went down in the Atlantic, remember that one. It was awful, like it just disappeared into the Atlantic and they couldn't find the wreckage for a very long time. I try to block out plane crashes. It was. It was a bad one. It was one of the worst, most recent ones. UM But they couldn't find the black box for two years and they finally found it and see order at twelve thousand feet after two years and when they brought the both of the black boxes up, they were able to get all of the data off of them. Wow, they were well made. Did it was it dumb luck or were they searching for it? Oh, they're searching for it, Okay, even though it stopped pinging, Ley just kept looking. Uh so you do recover it, hopefully, and then you need to analyze the data. So they're going to transport it to the h to a lab at the NTSP, the National Transportation Safety Board. We should say, the the country that this happens in, or if it's like an international waters the country that the airline is registered in is responsible for leading the investigation. Yeah, that makes sense. So in the United States would be the NTSP. Okay, yeah, sure, um. And just like any relic you find, if you know about finding undersea items that have been in salt water, you want to transport that in its own state that you found it, so in its own mess.

Yeah, like if it's it's the same thing as if you find a piece of sunken treasure. You don't want to bring it out and dry it off with a hair dryer. You want to keep it submerged in saltwater because that's where it's been living. And that's the sucking treasure pro tip from Chuck. I did an article on that. Actually that's how I know this, um. But yeah, so if if they find it in the ocean, they want to transport it in salt water and a cooler to a lab where they can really treat it right, give it the v I P treatment. Yeah. Um, and if the whole black box is still intact, you can actually just use it's it's computer interface. It's already installed this part of the recorder. Yeah, you can just plug it in and download all the stuff off of it. Yeah, it can be super quick. But oftentimes that stuff, like we said, is mangled and burned away, and so you have to just take the memory sticks and then you know, hook it up to a different machine so you can retrieve the data, that's right, which takes a little longer. Yeah, it can take weeks or months when you get the data. Obviously, when you have the data recorder data, you can feed that into a computer and create a simulation using a model to visualize what the plane was doing based on all those readings from all those different arrays. When you put them all together, it can create a computer model of the plane to show what it was doing at the time of the crash. Um The cockpit voice recorder uses a little more of human ingenuity to piece it together, and this takes way longer. Yeah. One thing you're gonna have is um a representative from the airline. You're gonna have a representative from the plane builder because they don't like their planes to go down. Um, there's gonna be ah, I guess whatever country or in your version of the NTSB is going to be there. And then sometimes they might have a translator or language specialist, depending on you know what nationality your your pilot was right, because I'm not to translate some stuff. And you have people who are trained in deciphering beeps and pings and not box airline cockpits, and they put all this together. It's a pretty interesting job, you know, um. And you you take that information, you put it together with the model, the simulation from the plane, the flight data recorder, and then these days also the flight computers send out warning messages like flight four four seven air France. It's sent out like twenty four warning messages, um in the four minutes before it crashed. So they had that already on hand, but nothing else. Yes, and then they started to piece it together after they went and got the wreckage, which we should say in some cases, when possible, they'll actually piece the entire plane back together to Oh yeah, I didn't know that Yeah, they'll get like a huge airplane hangar and take all the wreckage and pieces together piece by piece and try to get the plane back together to help that to help to help give a complete picture of what the heck happened. Did you see that the flight the Denzel Washington movie? And though I heard it was so depressing, it was good. Yeah. Man, they filmed that here too in Atlanta. But yeah, it was intense for sure. Okay, I'll check it out and then chuck um, it's not just airplanes where you can find black boxes, buddy, that's right. Uh, they're on trains. Planes already on planes, they're on trains and sort of a newish thing is putting versions of these and cars um either to give you like an insurance break. I think you can opt for these sometimes to prove that you're a safe driver and get it basically tracks like how fast you go and if you're speeding and taking turns too fast and stuff like that. Yeah, but they're a little controversial, I guess because I think in England you can actually get traffic tickets based on Yeah, I knew that was coming. Yeah, but some there's some car manufacturers that manufacture basically flight data recorders into their cars already. It's not necessarily recording like your cockpit conversation or anything like that, but it is keeping track of your car. It's like, um, you you know how, like your car will tell you that your tire pressure is low, or your doors open or something like that. There's something that's recording all that stuff, including all of your engine stuff and everything else that's part of your car too, which amounts to a black box. Because we left off we said that, you know, the point of having a black box is to figure out what the heck happened. We didn't quite go far enough. Because the point of figuring out what the heck happened it's not just to satisfy curiosity. But if there's a problem that's going to translate to other planes, to a mechanical failure, right, you want to go be able to fix it, or if there's a way to make planes safer in the future, um or prevent an accident. That's the whole point of the black boxes, to learn from tragedy. Yeah, they should put the voice recorders in cars for right. Yeah, for d why crash this guy sounds drunk? Pull them over, right? Focus, focus, Like you start hearing stuff like that, you're in big trouble. Like no one else is in the car. You're saying that out loud to yourself, but you're arguing about whether you should focus. I shouldn't be driving. Oh it's fine, right, we shouldn't be joking about that. That's like super sad. Well, this is a pretty pretty sad episode. Yeah, but we should make pretty sad episode suggested by like a four year old. I know what's going on with Cormack. I don't know. We'll have to get to the bottom of that. I don't know what kind of parenting is going on, and that a household. You are great parenting. I'm sure I don't have anything else. I don't you got anything else? I got nothing else. Well, we should like Cormack who This is how we originally got the idea for this episode. Um, we should let him play us out to listener mail, let's hear it. If you want to know more about Black Boss, you into us this search you are and you can have

fun at our fun and entertaining home on the web. Stuff you should know dot com. Al Right, Well, that was just too adorable. That's pretty cute. Maybe we should make that a regular thing. Yeah, so I have an idea. Okay, Um, you guys out there in podcast listener land, if you have a cute kid, you should record said cute kid doing our sign off for you know whatever, saying if you want to get in touch with me and chuck, tweet to us, join us on Facebook, YadA, YadA, YadA, and um, a cute kid that's a fan of the show, Like, don't just train your kid and force them to do something they don't know what they're doing exactly. So send us that email it to us. Email your permission for us to use it. Um, and uh, maybe we'll put it in some kind of supercut or whatever. Yeah, include whether or not you want us to say your kid's name or not? Right, all that j all the safety standard safety this is that's very exciting. We haven't had like a call out for anything in a while. Yeah, this could be cool. Nice. Well, okay, so it's a listener male time. Right. Yeah, I'm gonna call this, uh clearing up some kosher things. We've had a great response with our episode on Salt, so thanks for everyone that wrote in so far. Uh slight correction for you guys, on kosher salt, you work correct on its use of drawing blood out of meat as eating blood as against Jewish dietary laws. Simply salting the meat, though, will not make it kosher, which is a common misconception. To have a kosher meat, Firstly, you must have a kosher animal, one that choose it's cud and has split hoofs. While pigs have split hooves, they do not chew their cud. They are not kosher. Cannot be a scavenger, So no catfish or lobsters. No lobster, I saw that sign, felt, Oh yeah, that's right. Although fish is not considered meat, it is called parv p a r V essentially meaning neutral, as in not meat or dairy, which are never eaten together. And it cannot be a predator. So no hawks or chickens or no chicken hawks are chickens predators? Um, if you're a worm of chickens a predator, you know what I mean? All right? Secondly, guys, and this is key, the animal must to be killed in a ritual called chick thing by trained ritual s s H E, K H T I n G. The second H through me. This process involves a super perfectly sharp, rectangular ended knife that's about twice as long as the particular animal's neck. It is forbidden to stab or tear the flesh, hence the squared inn and sharpness. In one swift motion, the esophagus, trachea, herotid arteries, and jugular veins are all cut. The animal may not even feel it. Well, who's to say, uh? And we'll pass out and then die in seconds. The blood is then drained from the animal and after butchering, it assaulted with kosher salt to draw out the remaining blood and rinsed. You know, I knew a lot of that because I read this very very interesting article in Harper's Um several months ago, and this guy basically infiltrated the meat industry and like Nebraska or something like that, and he describes like a osher process of slaughter and how different it is from regular process. But then they have this special guy who's like a rabbi or something who works on this line at the slaughterhouse in in Nebraska. He's like a super specialized dude throat cutter. Yeah, but he uses like this incredibly sharp instrument. It was really good. He's a schecktor it's a really really interesting article. I can't remember the name of it, but I recommend anybody going and finding it. You know what, maybe you can post that in your blog. I have a blog. Yeah, you do your blog post about the best things you've read this week. Oh yeah, yeah, maybe you should throw it in there. All right. So those are the very basics of kosher meat, guys. Jewish dietary laws and certification are much too lengthy for an email or a single episode for that matter. It's very convoluted, highly recommended, delightfully witty book called Kosher for the Clueless but Curious by Simon Episdorff. I hope this is making words and names of I hope I've shed some light on this highly complex aspect of Judaism. That's from Michelle and Cedar Park, Texas. Thanks Michelle, just near Austin, UH. If you want to set its straight about something, we are always glad to hear more information like this is. We're kind of like sponges, you know. Um. You can tweet a short bursts of information on Twitter at s Y s K podcast. You can post this information at Facebook dot com slash stuff you should know, and if you want to send an email to Chuck, Jerry, and Me. You can address it to stuff podcast at how stuff works dot com. Stuff you Should Know is a production of iHeart Radio's How Stuff Works. For more podcasts for my heart Radio, visit the iHeart Radio app. Apple podcasts are wherever you listen to your favorite shows.