How Airplane Technology Works

about today? Today? I want to talk about um flying? Okay, you know, wait, we did our podcast about cell phone safety and whether or not it was safe to actually have a cell phone working on a plane, and then it occurred to us that there's a lot of really cool technology that planes use to not only take flight, but to get around to where they're going, and we

kind of wanted to touch on some of the systems. No, granted, a a really detailed discussion about airplane technology would probably take hours and hours, so again, this is going to be an overview, but we're gonna hit some of the uh the cool technology that gets you to where you're going when you're taking flight. Yeah, some of it's really really complicated. Other parts of it are just plane simple, ha ha. Alright, So with that in mind, let's go

ahead and get started. Did you have something in mind to start with. I was going to talk about sensors for because sensors you know, this is of course this is these are all the systems on the plane that tell it where it is, how fast it's moving, what's its relationship with other stuff that's in the area. And it's all obviously very important for the safety of the

plane and for navigational purposes. And there are tons of different kinds of sensors that we can talk about, but in general, the ones that are pretty much standard across pretty much any plane of significance would be you'd have to have something that keeps time right, so a clock of some sort um you iCal device, US econological device, and altimeter, which in general uses measures air pressure and determines how um how high up you are, UH, something

that can can detect and measure air speed UM and definite accelerometers both for vertical acceleration and horizontal UM. A compass of some sort so magnetic heading. You would need some sensors that would be able to uh indicate where the controls are, I mean, like what what setting they are in obviously UM fuel sensors, that kind of thing,

UH stabilizers. UM. All these sensors are very very important so that the pilot can make sure that everything is is UH as it should be and or make adjustments if things aren't quite right. And they also the equipment that needed to judge the state of the aircraft, like where the flaps are, the wheels, and all the other things that need to move, how much gas is in the tank jet fuel jet fuel. Yeah, well, you know,

we can simplify a little bit. I think I think we'll only get maybe ten or fifteen listener mails if we do that. UM. But yeah, all of this information gets fed UH to a flight data recorder as well as to the instruments on the pilot's console. And the flight data recorder is very important in the case of UH, something unusual happening, whether it ends up being an actual accident, which you know hopefully that's not the case, or if just something is not quite right and then they need

to review it at the end of the flight. UM. And the flight data recorder is located along with the cockpit voice recorder in UM in special a special kind of casing, and there's a very common term for this kind of casing. It's actually a very deceptive term. Considering what looks like a really sturdy box, well, it's called it usually a black box, even though they're not black, right, they're not black, and they don't really look like boxes. Necessarily.

They're usually bright orange UM because it makes it easier to spot if again, the unfortunate conclusion of a wreck occurs, if you've got a lot of wreckage, right, orange container stands out black not so much, especially there's been fire damage. So the black box, as they're known, UM, they shield the flight down of recorder and the cockpit voice recorder.

Actually there's often two different ones, one for each, and they're most often in the very back of the plane and the tail of the plane because that's going to be the area of the plane that suffers the least damage in case of an impact in most cases. Yep and UM. Actually, the information that goes to these machines is collected by the flight Data Acquisition Unit, which basically is a go between UH for the sensors and the black boxing. I'm still making a case that boxing should

be the plural for box. Well, I mean, you got good luck that anyhow, They basically have two separate responsibilities. The the cockpit voice recorder is used to record the voices in the cockpit. You don't say, I do say? Um, so yeah, basically all the all the communications in the cap and you know, in the actual cockpit itself, between the pilot and anybody else who happens to be in there, right, the co pilot and maybe another and anyone else who

actually is in the cockpit. Sometimes there are three yeah, officers in the cockpit or um and usually they it's taking taking a sound from the microphones that are located in the pilot's headset, that copilots headset. There's usually also another microphone that's in the cockpit itself. It's not connect to a headset. It's just there to pick up any other sounds and its warnings for example, right yeah, and it'll pick up like if there's a loud thud or

something along those lines. I mean, it'll that will help people figure out what happened after the event. So um yeah, everything that that goes on in the cockpits recorded there. Now, what's interesting is that, uh, it doesn't keep all that information forever. No, it actually, uh, depending on the the media upon which the voices are recorded. It will keep that for between thirty minutes and two hours. And in most cases now I think most of them have used

solid state tape solid state technology, can I not say that? Right? More times? Basically they used to use real to real tapes magnetic tape, um, you know, which has a finite beginning and end. Uh. The solid state flash type memory has the ability to you know, keep racing and um.

You know, it's also got the advantage of not having as many moving parts, right, yeah, it's it um also not uh yeah, it's not as vulnerable to damage as the magnetic tape is necessarily I mean, and U it can hold a lot more information to in a in a in the same physical amount of space. So yeah,

up to two hours, maybe even more than that. Actually that the latest I saw was two hours, but I'm guessing that you know, with the way that that solid state drives have have advanced over the last few years, I bet it's even higher than that now. But the idea being that after the reason why it would record over after the last couple of hours is the only reason you would need to review this in the first places.

If there was a catastrophic accident, and the chances are that anything that would really indicate a problem would have occurred half an hour or closer to the actual event.

You're not you know, it's not gonna you know, any problem that's that serious, that's detected earlier would probably result in an emergency landing, unless, of course you were maybe over a huge body of water and couldn't do that right, Right, So that's the reason for the you know, that's why you're not too concerned over the fact that's going to record over the previous you know recording, UM, the flight

data recorder. That's very important as well, because it will record all the conditions that were uh that we're leading up to the incident, and then of course everything thereafter, and that gives investigators a chance to really determine what it was that caused the problem in the first place.

And uh, I mean that's important. You know, if it's a manufacturing error, then obviously that's something you have to address, because what if that affects everything else in the fleet of planes or everything that's you know, of that same designation, right, I mean, this is um it's gonna track all kinds of information about the aircraft. Uh, you know, including stuff that I said before, all about the flaps, the positions

of the flaps and and things like that, air speed. Um, and based on the conditions and uh, you know, maybe the weather conditions in the area and anything that the pilot might have said. They can sort of piece together what may have happened in the event of an accident right now, and they're there are plenty of transcripts out there from that. We're taken from black box recordings, and uh, I tried reading a few of them, and after a couple, I'm like, I can't read any more of these. It's

a little too intense for me. Um. You might wonder water these these black boxes made of these black boxes that are neither black nor boxes. Um. Well, you've got

an aluminum housing that surrounds the sensitive equipment. Then you have you have some insulation that goes around that because of course, if there is a fire, right and jet fuel burns pretty hot, yes, so you have to have something that can withstand intense heat and protect the electronics insided so that people when they recover the electronics can figure out what happened. Um. And then around that you have a stainless steel shell. Wow. Yeah, so I mean,

and people often make that like that. I've heard comedians make the joke of, you know, when there's an airplane crash, they find the black box and it's fine, Why don't they make the whole airplane out of that hauh? Because it be way too heavy, that's why. But that's not funny. I guess. I guess if you stand up and you and you talk back to a comedian who's doing observational humor, and you explain in logical terms why the joke would

not work, that makes it less funny. I suppose I would imagine that that would not endear you to your fellow you know, crowd members. Yeah, that that explains why I'm no longer allowed in the chuckle hut. So yeah, do you like that? I just came up with it, all right. So another thing that these uh, these black

boxes have usually is an underwater locator beacon. Oh yeah, yeah, that would be very useful well, of course, Yeah, if you if you do happen to have an emergency water landing or a crash, you would need to have some way of being able to find this this device underwater and the way these systems work is they have a sensor that will detect if the black box goes underwater,

and then it activates a a subsonic signal. Actually I'm sorry, an ultrasonic signal, so I should go the other way, not subsonicum, ultrasonic signal, And so you can't hear it, but it can be detected by UH wall detection equipment, so people searching around the area using the right equipment can locate it very quickly. Right, so it's a pitch

so high that only underwater dogs can hear it. Right, it might affect the behavior of dolphins in the area, but other than that, right, And even despite that, of course, um, they can't always find some of the the black boxes. I mean that happened in the case of that that crash in the ocean earlier summer or two thousand nine. Um, as far as I know, last i'd see they had they'd given up looking for it because they were unable to find that signal. Yeah, well, I mean there are

many things that could affect that. I mean you're talking about, like the wreckage of a crash can spread over a very wide area, so that makes it difficult. Then of course you have things like currents and the depth of the water exactly. Um was not exactly known for not distorting audio, right, Yeah, so it might depending on many different uh factors, you may or may not be able

to find that very quickly. But that's the whole purpose of it is to to try and facilitate that, make it a little easier, so that the answers can can be found too. I mean, anytime there's a crash, there's gonna be lots of questions about exactly what happened. You know, was it human error, was it mechanical error, was it you know, unexpected turbulence, all that kind of stuff everyone wants to know. I mean, you know, it's a very traumatic experience. Um, moving on to unless you have anything

else about black boxes. I was going to move on to a different technology now. I was going to say, you know, that's you know we've been talking about that's kind of a somber one way. You always have something else that's not not so somber. Um, this is this isn't necessarily upbeaten chipper. It's just a neat technology. I was gonna talk about transponders. So transponder is a well the word transponder. It's kind of a combination of the

words transmitter and responder. That's a transponder. The idea is that it's a device that when you send a signal, it automatically sends a signal back. And it was very useful during World War Two because what they used. The way the military used transponders was it was a way to identify planes as being allied planes. Clearly, I mean, you wouldn't want to fire upon an allied UH airplane.

That's a typically considered a bad tactic in warfare, as I understand it, So you would not want to fire upon one of your own allies that you've got this transponder. You send a signal out, you get a signal back, you see that this is one of the signals that

UM signifies a friend, you don't fire upon them. Now in commercial jets, it's more of a way to identify the plane and make sure that you're that they're on the right track, they're on the right flight path, UM and UH so it's very useful for air traffic control and UM. I used to have to write a lot about transponders. One of my first jobs out of college was I was working for a particular airline which I

will not name. But um, my job was to take really old sound files, uh that were descriptions of the various systems aboard their airplanes and transcribe them because they lost the hard copy scripts. So I got to listen all day two sound files about things like the seven forty seven and and write down everything about all their various systems. Yeah. That was my job for about well a couple of months. Really that long. Yeah, I'm impressed as you made it that long. Well, it was a

temp job in the first place. It wasn't it wasn't a permanent assignment. Yeah, no, I know, I know more about the m D A eight than I cared to remember. Well, um, you know, actually transponders are very important because they lead to some non airplane airplane tech too. Yeah, because not just using aircraft. Well that's that's not exactly what I meant, because part of um, the tech used in flying a

plane is based on the ground. Well that's true too, because the transponder is used by air traffic control, very human piece of airplane tech to keep an eye on everything and there. Um there's we have an article on um that actually sort of you know, went through and made some minor changes on not too long ago about uh, the how the f a A A works. It's kind of thing because you realize that the FAA is tracking those

planes pretty much everywhere. They are using that transponder signal, um, using the ground control equipment and basically they subdivide the country into different sections and with each individual. I mean, you know that transponder code from that particular aircraft is unique to that plane. So, um, you know that's a very important part at tech because at any given moment, they're they're aware of where that is. That's true, That's true.

And of course we now also have the um the wonderful technology of GPS, and many planes have a GPS receiver that so that the pilot can see very quickly exactly where the plane is. And um that's often a useful thing, especially in really bad flying conditions. Uh, I was gonna talk a little bit. And and the GPS also comes in handy if you have to be sitting on one of those planes that has the monitor in the back of the seat in front of you and

you get want a track where you're plane is. Yeah, it gives you the flight track information and you're like, wow, we're directly over Tucson right now. Um. But I was also going to mention there's some other tech on on planes that it's a little more recent that. Uh. I thought i'd chat about the WiFi that you can get on some planes. Now, okay, I have an older piece of tech too, So do you want to do that ahead? No? No, no, it's okay. If we're going chronologically, then I should skip

back real quick. Shoot for it. One, two, three, shoot all right, all right, Chris, one, go ahead, Um yeah, I l S. Oh all right. Um. The I l S system is basically tells a pilot where he or she is with regard to a runway. Um. It actually uses combination of radio signals based around, um, the runway itself and uh so maybe the runway is obscured by clouds.

Um it will you know use sort of. It uses a combination of altitude, well, the glide path and then also the uh you know, it's the excuse me, Instrument Landing system is what I l S is short for. So it basically is giving them a combination of while you are right here with regard to the runway. Uh, you should you know, turn this way a little bit

and you'll be lined up with the runway. So even if he or she can't see it, um, they know exactly where it is based on the signals generated from the ground, and you know, they coordinate that with where the plane is. So that's a very useful piece of definitely technology because if you've ever wondered when you're coming into an airport and it's cloudy out and they make a perfect landing, that's how they're doing it. They're relying on that instrumentation to help them help them find where

they are. Also, the orientation really important. Whenever Johnny unplugs the lights on the runway, that happens in so few circumstances that that's problem. Surely you can't be serious, um, all right, so now we'll go on to the WiFi. Alright, the WiFi, No Johnny's on the ground. So yeah, WiFi

on planes is fairly recent. Um. It's something that had been discussed, uh well for a few years now, and a couple of companies have been doing it for since about I guess around two thousand and six, but in the United States it's a little more recent than that.

And um, it's a it's a pretty simple system. They there's some technology, there's equipment that's put aboard the plane that turns it turns it into a hot spot essentially, and your laptop or other device can connect wirelessly to this using typical WiFi technology, and then the hardware on the plane actually sends that signal down to the ground to towers on the ground and communicates that way. And that's how you are getting acces us too, uh, the Internet.

So it's not like, you know, you're you're not tapping into this magical Internet that's all around you in the air. Um. Really, the reason why you're able to do it is because the plane has a very specific kind of transceiver. Really, it's a very very long Ethernet cable. Yes, right, there's there's some poor schlubs job to just keep unwinding that cord and then another poor poor person's job to wind it all. No, it's not wired. Man, Talk about the letters we would get from that one? Yeah? Um, was

that all with WiFi? Yeah? That was all I had for a WiFi. It was just really it's just interesting to me that it's you know, again, you're turning the plane itself into a hot spot, and depending on what airline you're on, you'll see that they have different um uh, different pricing plans for it. Um. Some some people found difficulty, um. People, some companies found difficulty implementing this and making it uh profitable. UM. I think Boeing did it briefly and then jumped out

of it in the connection. Yeah yeah, I think. Weren't they charging like thirty bucks a flight or something like that. I don't know about the price point, but I do know that they've done They've washed their hands and yeah, yeah, what happened was, as I recall, the way it worked was they were charging thirty bucks for per flight. No. I don't know that necessarily um scale depending on the

length of the flight. But because most people weren't willing to pay about as much as it costs to have WiFi for a month at your house for a single flight, um, it ended up not making Bowing very much money and they abandoned the project. But other you know, like actual airlines have have implemented this on their own and um, there are a couple of companies that partner with to do that. Yeah. Um, and they give you broadband speeds of slowish DSL, So I mean it's it's fast, but

not really really fast. Yeah. Yeah, most people I think will be using it to do things like checking l I mean you might have a few folks who are you know, wanting to use it to to use Hulu so they can avoid having to watch whatever the movie is on board the plane. Yeah, there's only so many times you can watch Uncle Buck, by the way, is the number of times that would be a good segue into a satellite TV though? Um? Now, you know a lot of era carriers now offer satellite radio and satellite TV.

Um and um, they're the signals are a little bit different. Satellite radio is not nearly as directional. Uh. So you know, really it doesn't matter. The antenna position doesn't matter nearly as much as it does for a satellite TV. If you're a person that owns a satellite dish, uh, and it's in your yard and you know, the neighbor's kid kicked a soccer ball into it, and it looks like it's position right, but it through your TV signal off.

You know that satellite TV signals are a bit more directional. Well, you say, is there a little you know? Uh? William Shatner type guy out on the wing repositioning that side light dish. William Shatner was inside the plane. Okay, that's not sorry, shall I shall I restate there's not a little uh, you know, gremlin like William Shatner saw through the window of the plane. UM out there repositioning the satellite dish and actually uses for satellite TV on a plane.

You actually have a specialized antenna that tracks the position of the satellite and automatically corrects itself so that it can maintain its line of sight to the satellite UM and continue to receive satellite TV signals. That's pretty it's kind of a you know, considering the cost of a regular dish they would put it on the side of your house. It's considerably more expensive than that. UM. I

don't know how much they are now. They used to range in thousands of dollars, of course, you know, compared to the cost of an entire plane. That's nothing, um, not literally peanuts. Those are actually cheaper well you know, and may cause allergies, um, making tain nuts right, UM. But you know that's kind of an interesting technology too, because it has to it can't just it's not like a you know, a terrestrial antenna where just you know, stick a thing on top of the car and it goes.

You actually have to pay attention to where the satellite is. Um, that's kind of a neat little gimmick. Cool, Well, do you have anything else anymore airplane tech you want to talk about? You know? Not? Really? All right? Well, I'm I'm actually I'm all tapped out. So, like we said, this is just another kind of overview because there's plenty more that we could talk about, but not not more

that we're prepared to talk about. It's sort of a high level maybe thirty five thousand feet, Yeah, it's right around there. Turbulence. We'll we'll, we'll descend to maybe, you know, eight thousand if that happens. This has been a turbulent podcast. So with that, let's let's just go ahead and move on to a listener mail. And this listener mail comes from Matt and Uh. I cut out a lot of Matt's email, but I've got the crux of it here, and Matt says, Hey, Chris and Jonathan, I was wondering

what the differences between virus protection and internet security. Do I need internet security or just anti virus what makes internet security costs so much more. Some people also say that I should have a program specifically for spyware removal along with my virus protection or whatever. Is this true, sincerely, Matt. Now, what Matt was referring to were some specific products that are on the market for anti virus and internet security. Um So, Matt, here's kind of what all that means. Now.

An anti virus program in general, specifically is designed to search out any signs of viruses on your computer and often other kinds of malware to trojan's that kind of thing. Yeah, pretty much, a malware detection program is what that is. And most anti virus, if it's if it just says anti virus, that's really what it does. It goes after malware, uh, anti spyware that's looking specifically for any sort of tracking

software that's being put on your computer. Basically anything that's gonna phone home with information about you anywhere from your passwords and uh, you know, personal information like that, to you know, marketing type spyware where it's just saying, yeah, you know, he's visiting two and three websites and these are what they are, right, he's really interested in shoes, so you should send him targeted marketing. Yeah, that kind

of stuff. I mean, that's not nearly as annoying as uh some of the other stuff, but it is annoying, right, Yeah, it's it's pretty irritating. And so again, if it just says anti spyware, that's pretty much all it's looking for. UH. Internet security packages tend to have all of that wrapped up into one UM product and often have a firewall and in their firewall as well, so you'll have a firewall which can protect against intrusions from from outside your

your network. You'll have the antivirus who have the anti spyware. So that's why it's more expensive. It's because it's actually packaging together lots of stuff. Now, there are lots of UM lots of UH products on the market, some of them are actually free. So really what I suggest is research these different products, find the one that's right for you. We don't really review products, and uh we don't really feel feel comfortable making a recommendation UM, especially since we

don't necessarily know what kind of machine you're running. UH. Some of the you've got to also keep in mind the anti spyware and anti virus technology while it is scanning. They tend to be really um well because they're tracking everything that's going on in an attempt to protect you, and that can slow your computer down. Yes, exactly. Their resource hogs is what they really are. UM. I mean, they're very important to have, but they're gonna they're gonna

slow your computer down while they're running. UM Now, they'll just run in order to scan, and once they've scanned, you should be all right. Now. A lot of them have kind of ongoing software that will continue to monitor traffic as you are using your computer. UM, Like it might check your email attachments as they're downloaded to your computer and going, hey, this one's not good, right, don't open that um So, but yeah, just keep in mind it. Well,

these are very resource heavy. It's not something you don't want to constantly be scanning your computer. It's just gonna make take forever to do anything else. And uh also remember to keep it up to date. No matter what software you choose, UM make sure that you are. If it has an option to update automatically, I strongly suggest

you activate it. Yeah, there's a new trend to um cloud security where basically the software is there's like a little client in your computer, and it's basically constantly updating with virus definitions from the cloud. The bulk of the software is actually in UM on a computer somewhere else on the Internet, which is kind of cool. UM, But you know, it's still very new, so I haven't heard

a whole lot about how they're doing right now. Obviously that the reason why updating, of course is so important is that people hackers are always working on new kind of viruses and malware. Yeah, they take old viruses and add a twist to them so that the old virus protection software can't recognize them any right, So that's why you want to make sure you keep it up to date, because as the security firms find out about them, that they add definitions to their software so that it can

be detected and prevented. So hopefully that answers your question. Matt Um, Thank you very much for writing in. I thought i'd tell our listeners there's an interesting new way you can you can catch our podcast now. Actually catch it from the house stuff works dot com website. So if you go to house stuff works dot com, you go to the little search baring type and tech stuff.

It'll take you to the tech stuff podcast page, and we have a little player and individual player that you can listen to episodes right there if you want to. It also has nice options for sharing it via email or Twitter, Facebook. Um, it's got a little option where you can pop the player out of the web page and have it being a little independent player on on the side. A lot of neat features and uh so, I just want to let you guys be a you know,

make you guys aware of that. In case you're ever on a different computer and you don't have your iTunes accounts set up or something like that. Um, you can still listen to us. Please please listen to us. We're lonely, and if you have anything you want to say to us, you can send us an email or addresses tech stuff at how stuff works dot com. And you can learn all about airplanes and technology and computer viruses and security all at how stuff works dot com. Crispy and I

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