WEBVTT - TechStuff Classic: TechStuff Goes on Autopilot 0:00:04.240 --> 0:00:07.240 Welcome to tech Stuff, a production of I Heart Radios, 0:00:07.320 --> 0:00:13.600 How Stuff Works. Hey there, and welcome to tech Stuff. 0:00:13.600 --> 0:00:16.479 I'm your host Jonathan Strickland. I'm an executive producer with 0:00:16.480 --> 0:00:18.480 How Stuff Works and I heart Radio and I love 0:00:18.560 --> 0:00:21.640 all things tech. And you know what time it is. 0:00:22.480 --> 0:00:26.880 It's showtime. Showtime. Also time for a classic episode tech Stuff. 0:00:27.400 --> 0:00:32.159 And this episode originally published on May one, two thousand twelve. 0:00:32.760 --> 0:00:36.279 Chris and I phoned it in. We walked into this 0:00:36.360 --> 0:00:39.880 podcast room. We just sat down and we went on autopilot. 0:00:39.920 --> 0:00:42.880 But that's okay because the episode was tech Stuff goes 0:00:42.920 --> 0:00:46.960 on autopilot, So get ready to learn all about autopilot. 0:00:47.240 --> 0:00:51.400 Take it away past Jonathan and Chris. So today we 0:00:51.440 --> 0:00:54.680 wanted to talk a little bit about, um, well, something 0:00:54.720 --> 0:00:56.600 that Chris and I do all the time, which is 0:00:56.640 --> 0:01:00.560 to go on autopilot like we do in this podcast 0:01:01.200 --> 0:01:04.959 oh every darn week. Um No, we want to talk 0:01:05.000 --> 0:01:08.640 about the autopilot systems in airplanes because you know, you 0:01:08.920 --> 0:01:12.959 often hear that phrase about switching on autopilot, But what 0:01:13.040 --> 0:01:15.479 does that actually mean? What's it? What does that entail? 0:01:15.640 --> 0:01:18.560 How did we come up with this idea? You know, 0:01:19.200 --> 0:01:22.720 because it kind of has a sort of almost magical 0:01:22.800 --> 0:01:25.440 air about it for anyone who is uninformed about the 0:01:25.440 --> 0:01:27.959 way autopilot works. Right, Like, there's a big red button 0:01:28.040 --> 0:01:31.199 that says autopilot. You press it and pressed dough Everything's cool, 0:01:31.560 --> 0:01:34.720 you said, air. Um, there's gonna be a lot of that. 0:01:34.800 --> 0:01:37.360 Let's get that out of the way right now. Yep, yep, 0:01:37.520 --> 0:01:41.040 and uh. I'm a fan of Patrick smith On. Salani 0:01:41.120 --> 0:01:42.840 has a column called Ask the Pilot, because he's a 0:01:42.880 --> 0:01:45.440 pilot and people ask him questions about things like what 0:01:45.520 --> 0:01:47.319 happens at one of the engines falls off a jet 0:01:47.880 --> 0:01:52.040 that kind of And he answered bad things, yes, but 0:01:52.320 --> 0:01:54.240 you know, not as bad as if all the engines 0:01:54.480 --> 0:01:57.160 on the jet. Right, No, but I'm thinking about it 0:01:57.200 --> 0:01:59.559 depends on if you are under the jet at the time. 0:01:59.640 --> 0:02:03.560 That's true. Um, but yeah, I mean. And and one 0:02:03.560 --> 0:02:05.400 of the things that he says a lot of people, 0:02:06.080 --> 0:02:08.160 He's mentioned this several times. People seem to think that 0:02:08.480 --> 0:02:10.839 the pilot can get in the cockpit, close the door, 0:02:10.960 --> 0:02:13.000 push the red button, and the plane will fly itself 0:02:13.040 --> 0:02:15.959 to the next destination. And he gets out and thank 0:02:15.960 --> 0:02:18.839 you for flying with us, And it doesn't quite work. 0:02:18.960 --> 0:02:21.560 Then he collects the big fat check for all for 0:02:21.680 --> 0:02:24.919 pushing a button. Yeah, it doesn't really work that way, 0:02:25.000 --> 0:02:27.839 and you can do a lot, but it can't do that. 0:02:28.000 --> 0:02:30.440 It can it can even land a plane depending on 0:02:30.520 --> 0:02:34.520 the conditions and the systems aboard. But let's uh, let's 0:02:34.600 --> 0:02:36.959 let's take it back a step first. Let's talk about 0:02:37.080 --> 0:02:41.320 sort of the development of autopilot. So way back in 0:02:41.520 --> 0:02:46.120 nine there was a fellow by the name of Elmer Sperry, 0:02:47.440 --> 0:02:51.760 and he was developing something called a gyro compass, and 0:02:52.040 --> 0:02:55.040 it was it was using a gyrocompass and other sorts 0:02:55.080 --> 0:03:00.480 of gyroscopes that in combination could work with a system 0:03:00.520 --> 0:03:06.079 on an on a plane to allow a automated steering. Essentially, 0:03:06.080 --> 0:03:08.440 what it did was it just kept the steering steady. 0:03:09.000 --> 0:03:10.840 It's you know, it's kind of like, you know, this 0:03:10.960 --> 0:03:14.040 idea of just uh, you're on a steady heading and 0:03:14.080 --> 0:03:17.560 it keeps you on that. UM And the first test 0:03:17.639 --> 0:03:23.040 flight of a a plane with um this sort of 0:03:23.080 --> 0:03:28.960 autopilot system was performed by Lawrence Burst Sperry, son of 0:03:29.000 --> 0:03:32.320 Elmer Sperry, which was again right around nineteen o eight, 0:03:32.960 --> 0:03:35.560 and they used four gyroscopes to help stabilize the plane. 0:03:35.600 --> 0:03:39.760 So the gyroscopes depending on their attitude. And I don't 0:03:39.800 --> 0:03:43.040 mean whether they were friendly or not. Forget you, you 0:03:43.040 --> 0:03:45.480 could fly to the playing yourself. I mean their position 0:03:45.800 --> 0:03:49.960 relative to the rest of the environment would dictate how 0:03:50.000 --> 0:03:53.320 the system would work. And so that was that they 0:03:53.360 --> 0:03:57.240 developed the first true autopilot system, which was later used 0:03:57.560 --> 0:04:00.960 by a fellow named Wiley Post which is just a 0:04:01.000 --> 0:04:05.160 great name. Yeah, you know, he's an His name is 0:04:05.200 --> 0:04:07.120 one of those names that you hear every once in 0:04:07.160 --> 0:04:10.400 a while. Um. He was famous back in in in 0:04:10.520 --> 0:04:15.800 his time, which was the earliest part of the twentieth century. Yeah, yeah, 0:04:15.800 --> 0:04:19.080 famous aviator and his name sort of just comes up 0:04:19.120 --> 0:04:21.400 every once in a while. Is him? I know that name? 0:04:21.440 --> 0:04:24.400 Why is he famous? Well? Is it turns out he uh, well, 0:04:24.400 --> 0:04:28.000 he flew across country. Yeah, and made headlines with that, certainly, 0:04:28.080 --> 0:04:30.000 and then he flew around the world. And the first 0:04:30.000 --> 0:04:31.560 time he flew around the world, he flew around the 0:04:31.560 --> 0:04:34.960 world with a navigator. Took a long time for him 0:04:35.000 --> 0:04:37.040 to get all the way around the world. Um. And 0:04:37.240 --> 0:04:40.520 but the navigator was there too, not just navigate, but 0:04:40.600 --> 0:04:44.240 also make sure that that Wiley remained wildly Yes, and 0:04:44.480 --> 0:04:48.920 he was alert and thank you, alert and capable of 0:04:49.120 --> 0:04:52.480 maneuvering the plane and not just you know, any time 0:04:52.600 --> 0:04:55.360 anyone has to do a monotonous task for a really 0:04:55.360 --> 0:04:58.039 long time, there's a danger that we will go on 0:04:58.080 --> 0:05:00.680 autopilot as and we'll stop paying it tension, and then 0:05:00.760 --> 0:05:04.960 disaster can can strike. So he had a navigator. Well, 0:05:05.040 --> 0:05:07.480 then he decided that he wanted to try and do 0:05:07.640 --> 0:05:11.400 a solo flight around the world, and this is three 0:05:12.040 --> 0:05:14.680 and so in order to do a solo flight and 0:05:14.720 --> 0:05:17.440 still be able to rest and you know, because these 0:05:17.720 --> 0:05:20.960 these flights were taking hours and hours and hours at 0:05:20.960 --> 0:05:23.600 a time just but you know, from one spot to 0:05:23.640 --> 0:05:27.680 the next before refueling and uh uh, you know, it's 0:05:27.760 --> 0:05:31.200 it's a long time to stay awake. So he would 0:05:31.240 --> 0:05:34.359 have had this, uh, this system developed by the Sperry's 0:05:34.680 --> 0:05:37.880 that would help keep the plane on course so that 0:05:37.920 --> 0:05:43.400 he could rest because otherwise, uh, he would probably have 0:05:43.480 --> 0:05:46.360 gone crazy. You know, you go without sleep long enough 0:05:46.600 --> 0:05:50.160 and you start to go bunkers. So that was a 0:05:50.279 --> 0:05:54.400 very important development, and it's today autopilot is part of 0:05:54.440 --> 0:05:56.599 something a little more sophisticated. Back then it was it 0:05:56.640 --> 0:05:59.479 was a fairly simple system, but now it's part of 0:05:59.520 --> 0:06:03.120 the auto matic flight control system. Which in turn is 0:06:03.279 --> 0:06:08.120 one component of an airplane's avionics system. And before we 0:06:08.160 --> 0:06:09.760 go too far into this, I do want to say 0:06:09.839 --> 0:06:11.880 we have an article on how stuff Works dot com 0:06:11.880 --> 0:06:15.120 about how autopilot works, and it's an excellent article. I 0:06:15.160 --> 0:06:17.039 do recommend you go check that out if you want 0:06:17.080 --> 0:06:19.720 more information. We're going to give you the rundown on it, 0:06:20.160 --> 0:06:22.800 but it's it will help a lot if you want 0:06:22.839 --> 0:06:25.440 to look further into it. There's a great article on 0:06:25.480 --> 0:06:28.039 our site is by William Harris as a matter of fact, 0:06:28.320 --> 0:06:30.320 who used to be one of my writers as well. 0:06:30.400 --> 0:06:33.440 So yeah, so an avionic system in case you're wondering 0:06:33.480 --> 0:06:35.680 what that is, you know, we just mentioned that the 0:06:35.680 --> 0:06:38.320 the automatic flight control system is part of avion X. 0:06:38.640 --> 0:06:42.360 Avionics refers to electronic systems aboard a plane that are 0:06:42.800 --> 0:06:46.159 really designed to help control the plane and the key 0:06:46.200 --> 0:06:49.480 elements of flight. And the other systems that are involved 0:06:49.520 --> 0:06:55.279 include things like navigation, collision avoidance, communication, UH and weather systems. 0:06:55.920 --> 0:06:59.240 So these are the very important systems that allow pilots 0:06:59.279 --> 0:07:04.160 to to do their job and get as much information 0:07:04.440 --> 0:07:07.080 and have as much control over the aircraft as possible. 0:07:07.720 --> 0:07:11.280 And so yeah, they're really the original purpose of the 0:07:11.360 --> 0:07:14.679 autopilot was to help pilots be able to take little 0:07:14.720 --> 0:07:18.600 rest breaks, especially when doing something that's truly tedious, like 0:07:19.280 --> 0:07:23.680 cruising at high altitude. When you're well, you're you're you've 0:07:23.720 --> 0:07:28.320 reached your your cruising altitude like thirty feet and that's it. 0:07:28.640 --> 0:07:31.400 You're you're stuck there for however long the flight is 0:07:31.440 --> 0:07:33.320 going to be before you have to start taking her down, 0:07:34.000 --> 0:07:37.280 and that can get you know, if you if you've 0:07:37.280 --> 0:07:39.560 got several flights a day, that can get pretty tiresome. 0:07:40.120 --> 0:07:44.160 So the autopilot helps the the pilot kind of offload 0:07:44.240 --> 0:07:47.920 that so that the pilot is in the best shape 0:07:47.960 --> 0:07:50.880 to bring the plane in for landing or dealing with 0:07:50.920 --> 0:07:57.040 any other unusual circumstances or even things like turbulence. Yeah. Yeah, 0:07:57.040 --> 0:08:00.240 If it's a smooth flight, it shouldn't be much trouble 0:08:00.280 --> 0:08:04.840 for the autopilot to keep the plane going where it's going. Um. 0:08:04.920 --> 0:08:08.760 And and it does that through a series of well 0:08:08.920 --> 0:08:14.679 course corrections. Really um. As it turns out, it's basically uh. 0:08:14.760 --> 0:08:19.200 The idea behind the auto autopilot itself is pretty simple. Um. 0:08:19.320 --> 0:08:21.920 You have several control surfaces, and we talked about this 0:08:21.960 --> 0:08:25.320 in the past. You have control surfaces on the wings 0:08:25.800 --> 0:08:29.120 and on the vertical stabilizer uh known to those of 0:08:29.200 --> 0:08:33.680 us and the uh you just talking about planes sort 0:08:33.720 --> 0:08:37.560 of world that tail um and uh you know you 0:08:37.960 --> 0:08:42.160 basically controls h It consents what's going on. It says, oh, well, 0:08:42.200 --> 0:08:45.120 we're descending a little bit. We need to adjust the 0:08:45.800 --> 0:08:48.839 control surfaces to change the airflow and get the plane 0:08:48.840 --> 0:08:53.000 back up. You know these ten feet that we've dropped. UM. 0:08:53.120 --> 0:08:55.560 So it's at all it does is it's basically and 0:08:55.800 --> 0:09:01.200 I'm grossly oversimplifying it, but um on purpose. So yeah, basically, 0:09:01.200 --> 0:09:03.000 all it's doing is saying, oh, we need to we 0:09:03.040 --> 0:09:04.640 need to fix this, we need to adjust this and 0:09:04.679 --> 0:09:07.079 get it back to where we were. Um. And then 0:09:07.120 --> 0:09:10.200 it just makes these very subtle course corrections to get 0:09:10.200 --> 0:09:12.520 to keep the plane more or less where it is. 0:09:12.520 --> 0:09:15.040 When the pilot hits the big red button. I don't 0:09:15.040 --> 0:09:18.000 even know if the big red button exists. It's playing 0:09:18.040 --> 0:09:20.400 for what we're talking about, right. So, So to get 0:09:20.440 --> 0:09:23.880 a little more in depth with this, uh, you you 0:09:23.920 --> 0:09:28.800 have a closed system, and that closed system includes sensors 0:09:28.840 --> 0:09:31.880 that are on these control surfaces as well as other 0:09:31.960 --> 0:09:36.199 sensors that are part of the planes systems that provide 0:09:36.440 --> 0:09:40.400 information to a computer. Now, the computer takes this information 0:09:40.760 --> 0:09:44.120 compares it to whatever command the pilot has given. For example, 0:09:44.160 --> 0:09:47.400 the pilot might say I want to maintain this altitude, 0:09:47.600 --> 0:09:51.080 this speed, and this course. And then what happens is 0:09:51.080 --> 0:09:54.280 the computer takes the information gathered by the sensors, compares 0:09:54.320 --> 0:09:57.240 it to the command given by the pilot, and then 0:09:57.320 --> 0:10:02.040 makes any adjustments necessary in order to maintain that that command. 0:10:02.760 --> 0:10:08.080 Now that might mean sending information to a a servo 0:10:08.559 --> 0:10:12.760 that will adjust one of those those control surfaces to 0:10:13.400 --> 0:10:16.040 make a bit of a change, either to turn the 0:10:16.080 --> 0:10:18.880 plane a little better, raise and go up in altitude 0:10:18.920 --> 0:10:21.920 or lower in altitude, whatever is necessary in order to 0:10:22.080 --> 0:10:25.600 maintain the command that was set by the pilot. So 0:10:25.640 --> 0:10:28.960 those those three basic control surfaces that Chris was alluding 0:10:29.000 --> 0:10:32.760 to include elevators, which that's on the tail of the plane, 0:10:32.760 --> 0:10:34.760 and that helps control the plane's pitch. So if you 0:10:34.800 --> 0:10:38.120 imagine a plane that let's say that you're balancing a 0:10:38.120 --> 0:10:41.320 plane along its length, so it's you know, it can 0:10:41.360 --> 0:10:44.320 tilt forward or backward the pitches. That's what the pitch does. 0:10:44.400 --> 0:10:46.440 It allows the plane to either go up or down 0:10:47.400 --> 0:10:50.800 uh in uh angled in that way. Then you have 0:10:50.840 --> 0:10:56.560 the rudder, which controls the y'aw that that's what twists 0:10:56.640 --> 0:10:59.600 the plane. And then you have the ailerons, which are 0:10:59.600 --> 0:11:02.079 on the your edge of the wings. That's what rolls 0:11:02.120 --> 0:11:04.160 the plane to once that or the other. All right, 0:11:04.520 --> 0:11:07.760 So those are your three basic control surfaces that can 0:11:07.880 --> 0:11:13.280 do these these changes to the plane's attitude in flight. 0:11:13.600 --> 0:11:17.560 And depending upon the autopilot system you have, you may 0:11:17.600 --> 0:11:21.800 be able to have one or two or all three 0:11:21.840 --> 0:11:25.880 of those under automatic control. So, and it's pretty easy 0:11:25.920 --> 0:11:29.760 to understand. A one access, one access rather control system 0:11:30.160 --> 0:11:32.920 will control just one of those three surfaces, and it's 0:11:32.960 --> 0:11:35.600 usually the ailerons. If it's just gonna be one, it's 0:11:35.679 --> 0:11:39.760 usually that. Two access controls usually controls the elevators and 0:11:39.800 --> 0:11:43.480 the ailerons, and then three excess controls controls all three. Clearly, 0:11:43.520 --> 0:11:46.280 you wouldn't don't have like a fourth one poppat and 0:11:46.320 --> 0:11:49.840 then hey, what's this do forget you rudder? You never 0:11:49.920 --> 0:11:54.120 get controlled? Uh, it's not the case. So the depending 0:11:54.160 --> 0:11:57.600 on that system, the autopilot is in charge of making 0:11:57.600 --> 0:12:00.600 sure that the any adjustments gets send out to those 0:12:00.600 --> 0:12:03.640 different control surfaces to maintain the command that the pilot 0:12:03.679 --> 0:12:08.559 has made and the sensors include other things like gyroscopes, 0:12:08.600 --> 0:12:12.840 which help determine the actual attitude of the plane, how 0:12:12.880 --> 0:12:15.280 it's you know, whether it's tilted in one side or 0:12:15.320 --> 0:12:18.040 the other, or the pitch is wrong. That's what the 0:12:18.040 --> 0:12:21.080 gyroscopes can help with. And then you have acceleraters, so 0:12:21.640 --> 0:12:25.439 obviously determining what the speed is of the plane, whether 0:12:25.480 --> 0:12:30.880 it's undergoing any sort of acceleration or deceleration, altimeters which 0:12:31.200 --> 0:12:35.320 tell you how high up the plane is. That seems 0:12:35.600 --> 0:12:38.200 relatively important. And then a compass which tells you which 0:12:38.200 --> 0:12:42.840 way you're facing. Also the more. But over the last 0:12:42.840 --> 0:12:47.320 several years, the the autopilot system has also depended upon 0:12:47.760 --> 0:12:52.679 GPS receivers, which can let the autopilot system know where 0:12:52.760 --> 0:12:56.800 the plane is geographically and thus make any sort of 0:12:57.360 --> 0:13:01.520 course corrections in order to even plotical course to a destination. 0:13:02.120 --> 0:13:05.079 So there's a little bit more that can be offloaded 0:13:05.120 --> 0:13:08.240 onto a computer system. Now we're still not to the 0:13:08.240 --> 0:13:12.360 point where we're gonna have robot pilots. You know, these 0:13:12.760 --> 0:13:19.000 these autopilot systems are meant to help um help pilots 0:13:19.040 --> 0:13:21.920 rest and and and plan for other parts of the flight. 0:13:22.000 --> 0:13:25.439 But they're not replacements. Yeah, so make sure if you're 0:13:25.600 --> 0:13:28.040 a pilot that you watch what you eat before you, 0:13:28.800 --> 0:13:33.360 uh take over the controls. Oh, yes, I had to lasagna. 0:13:34.520 --> 0:13:38.240 This is bob. I'm mixing those up because it's airplane 0:13:38.240 --> 0:13:41.280 and airplane too. Okay, yeah, but yeah, you can you 0:13:41.320 --> 0:13:44.160 can tell um. You know from the very first uh 0:13:44.520 --> 0:13:49.199 when Wiley Post was using the the early Sperry system UM, 0:13:49.200 --> 0:13:53.320 which was based solely on on gyroscopes and compass readings, 0:13:53.480 --> 0:13:56.920 you know that that was a very simple version of 0:13:57.360 --> 0:13:59.800 what would later become these systems. And now that we 0:14:00.040 --> 0:14:03.560 have all these different um uh, different types of sensors 0:14:03.559 --> 0:14:06.920 and different types of input, the autopilot system can be 0:14:06.920 --> 0:14:11.679 a lot more accurate than those of the past UM 0:14:11.720 --> 0:14:14.319 and it has become a very very useful tool for 0:14:14.679 --> 0:14:18.400 an aircraft pilot to to rely on. Yeah. And also, uh, 0:14:18.600 --> 0:14:21.560 I should point out that these systems, with the servo 0:14:21.640 --> 0:14:24.880 mechanisms and everything that help control the surfaces, they are 0:14:24.960 --> 0:14:29.200 independent of the manual systems that are used by the 0:14:29.200 --> 0:14:32.120 pilot when the pilot controls the plane. Whenever he or 0:14:32.160 --> 0:14:35.720 she is controlling the plane, uh, it's an independent series 0:14:35.840 --> 0:14:40.040 of of servos and every and other elements that keep 0:14:40.080 --> 0:14:42.640 these surfaces moving. And the reason for that is because 0:14:43.120 --> 0:14:48.880 autopilot systems, like any other system, can fail, and UH 0:14:48.920 --> 0:14:50.920 in the case of failure, you want to have the 0:14:51.000 --> 0:14:54.400 option for manual control so that the pilot can take 0:14:54.440 --> 0:14:57.080 over and everything will be fine. And so in order 0:14:57.080 --> 0:14:58.560 to do that, you have to make sure there's some 0:14:58.600 --> 0:15:01.760 redundant systems there because as if it's a servo mechanism failure, 0:15:01.760 --> 0:15:05.800 which is frequently the case in an autopilot failure, then 0:15:06.040 --> 0:15:07.520 you want to make sure you still have a way 0:15:07.560 --> 0:15:10.640 of controlling that surface area or else you're really stuck. 0:15:11.040 --> 0:15:14.000 You've got some serious problems if if a system like 0:15:14.040 --> 0:15:17.880 that fails. Over, Macho grande, I'll never be over, Mancho grande. 0:15:18.520 --> 0:15:21.440 We've got more to say about autopilot in just a moment, 0:15:21.480 --> 0:15:24.200 but first let's take a break to thank our sponsor. 0:15:32.320 --> 0:15:35.080 The other thing that's important to remember is that if 0:15:35.120 --> 0:15:38.520 an autopilot system is engaged, meaning that it's working, not 0:15:38.640 --> 0:15:40.720 that it has found the right person and they're going 0:15:40.760 --> 0:15:44.920 to build a family together system. So a down and 0:15:44.960 --> 0:15:47.960 have a little being a little extra goofy this morning. 0:15:48.040 --> 0:15:50.720 For reasons I can't understand, other than the fact that 0:15:50.760 --> 0:15:52.800 we were not able to come in our normal studio 0:15:52.880 --> 0:15:55.080 time because stuff to blow your mind was taking up 0:15:55.120 --> 0:15:59.200 the space in front of us. So blame them anyway. Yes, 0:15:59.240 --> 0:16:02.560 when the autopo system is is active, you want to 0:16:02.600 --> 0:16:05.840 be able to turn that off before you engage manual systems, 0:16:05.920 --> 0:16:10.160 because otherwise, what's happening is you're fighting the autopilot because 0:16:10.160 --> 0:16:12.040 the changes you make, what's going to have is the 0:16:12.080 --> 0:16:14.760 sensors and the autopilot system pick up the fact that 0:16:14.800 --> 0:16:19.160 you've changed the or or that conditions have changed. So 0:16:19.200 --> 0:16:21.240 let's say that you're trying to bring the plane down 0:16:21.280 --> 0:16:25.360 to a different altitude and you start to do this 0:16:25.400 --> 0:16:29.120 and autopilot is already engaged. The sensors and autopilot start 0:16:29.160 --> 0:16:31.760 to say, wait a minute, now, we're now we're going lower. 0:16:31.840 --> 0:16:35.160 And he told me, he told me at the beginning 0:16:35.160 --> 0:16:37.080 of this flight that we wanted to maintain thirty four 0:16:37.080 --> 0:16:40.200 thousand feet. So, gosh, darn it, I'm gonna change the 0:16:40.360 --> 0:16:44.800 altitude of this here plane. So disengaging the autopilot is 0:16:44.920 --> 0:16:48.480 very important before taking over manually. Now, I'm sure there 0:16:48.520 --> 0:16:50.800 are many systems out there that have sort of an 0:16:50.800 --> 0:16:55.240 automatic disengaging uh process. So that if a pilot were 0:16:55.280 --> 0:16:58.120 to take the controls, the autopilot would would turn off, 0:16:58.160 --> 0:17:01.520 so that you wouldn't have a pilot and autopilot fight 0:17:01.600 --> 0:17:04.760 over where a plane is going. But there have been 0:17:04.800 --> 0:17:09.280 in the past a few UM accidents and incidents that 0:17:09.400 --> 0:17:13.760 were UH linked in one way or another two autopilot failures. 0:17:14.280 --> 0:17:17.720 A lot of experts that I have looked at UH 0:17:17.840 --> 0:17:20.199 the writings rather not the actual experts. I mean I 0:17:20.240 --> 0:17:21.880 look at them too, but they get a little self 0:17:21.880 --> 0:17:25.720 conscious after a while. But according to their research, it 0:17:25.880 --> 0:17:31.359 seems to me like autopilot failure is not generally a 0:17:31.680 --> 0:17:36.200 cause for for accidents. It tends to be something else 0:17:36.240 --> 0:17:39.720 that's happened. There have been a few cases where autopilot 0:17:39.760 --> 0:17:43.680 was disengaged and then perhaps turned back on again at 0:17:43.720 --> 0:17:47.040 a time when a plane was experiencing trouble, and that 0:17:47.280 --> 0:17:53.160 didn't help matters. But it doesn't look like autopilot failures 0:17:53.320 --> 0:17:58.360 often result in catastrophe, mainly because we have these well 0:17:58.359 --> 0:18:01.760 trained pilots that are in the cockpits that can take 0:18:01.800 --> 0:18:06.119 over when that happens. That's true, UM and UH. I 0:18:06.160 --> 0:18:09.720 think it's time to bring up some negative feedback. The 0:18:09.800 --> 0:18:13.240 negative feedback loop. Yeah. No, a feedback loop is basically 0:18:13.440 --> 0:18:16.800 a and then this doesn't necessarily have to be a 0:18:16.800 --> 0:18:19.359 an electronic thing. I was reading an article and wired 0:18:19.400 --> 0:18:22.960 about this. If you've ever seen those, um uh, those 0:18:22.960 --> 0:18:26.600 speed indicator things on the side of the road that say, hey, 0:18:27.080 --> 0:18:29.960 you know speed limits thirty five and you're doing forty two, 0:18:30.000 --> 0:18:32.760 pal slow it down and it flashes at you. Um, 0:18:32.800 --> 0:18:36.280 that's creating a feedback loop. They used that example specifically, 0:18:36.320 --> 0:18:40.440 so basically, UM, that article was talking about how they're 0:18:40.560 --> 0:18:44.040 actually fairly effective um at getting people to slow down 0:18:44.040 --> 0:18:48.400 because they're providing you feedback on what you're doing, and uh, 0:18:48.520 --> 0:18:50.560 that sort of creates this sense of, well, I should 0:18:50.600 --> 0:18:53.280 probably behave myself and stay close to the speed limit 0:18:53.280 --> 0:18:56.160 in this area, Um, I don't want to get pulled over, 0:18:56.520 --> 0:18:59.119 or or some people are thinking I don't want to 0:18:59.119 --> 0:19:02.120 get caught and other people are thinking I am going 0:19:02.160 --> 0:19:05.680 too fast for this neighborhood. Exactly. I think I think 0:19:05.720 --> 0:19:07.840 most of the people I encounter are of the first 0:19:07.880 --> 0:19:12.640 part where they look around, like, I don't see any cups. 0:19:12.680 --> 0:19:16.320 Just screwed up the levels there too, I'm sure probably, um, 0:19:16.359 --> 0:19:20.359 but but in this case, uh, the autopilot system uses 0:19:20.520 --> 0:19:24.879 a negative feedback loop. Um. So let's say you're flying 0:19:24.880 --> 0:19:27.919 at thirty four thousand feet okay, and uh, you know, 0:19:27.920 --> 0:19:30.879 I would imagine when I used ten feet before that 0:19:31.000 --> 0:19:34.240 was a I'm thinking that's probably a fairly subtle change 0:19:34.240 --> 0:19:36.800 for a plane in flight. So let's say it goes 0:19:36.840 --> 0:19:40.119 down ten feet, um, maybe as a result of a 0:19:40.119 --> 0:19:43.199 little turbulence or something, and uh, it sets off a 0:19:44.160 --> 0:19:47.159 you know, a signal in the processors because the sensors 0:19:47.200 --> 0:19:50.680 have detected that there is something. So that's negative feedback, 0:19:50.680 --> 0:19:53.280 and it says, oh, it's something's changed. It's not supposed 0:19:53.320 --> 0:19:55.639 to be this way. Fix it. And so it's just 0:19:55.720 --> 0:19:58.280 constantly going through this loop, is it okay? Yes, all right, 0:19:58.400 --> 0:20:01.560 never mind, don't do any yes, never mind, it's okay, 0:20:01.600 --> 0:20:04.679 we're tilting, all right, fix that. Yeah it's um. If 0:20:04.720 --> 0:20:07.320 you want to know another negative feedback loop mechanism that 0:20:07.359 --> 0:20:10.160 you're probably pretty familiar with, we did an entire episode 0:20:10.160 --> 0:20:14.000 about it, the thermostat. Because let's say you set your 0:20:14.040 --> 0:20:18.120 thermostat for we'll say seventy degrees because I like it 0:20:18.320 --> 0:20:21.800 right around there in my house, UM, so seventy degrees. 0:20:21.880 --> 0:20:25.640 So when the temperatures at seventy. Everything is copathetic. Nothing 0:20:25.680 --> 0:20:28.720 gets turned on. As soon as it starts hitting seventy one. 0:20:29.240 --> 0:20:33.840 Then you have the system click into place. The air conditioning. 0:20:34.480 --> 0:20:39.120 The air conditioning system itself starts to starts to fire up, 0:20:40.040 --> 0:20:43.680 which ironically makes it cooler. And uh then it starts 0:20:43.680 --> 0:20:46.359 blowing cool air through the through the house. And once 0:20:46.440 --> 0:20:50.199 the air has become cool enough around the thermostat and 0:20:50.240 --> 0:20:54.359 the internal thermometer detects it, then it switches back off again. 0:20:54.400 --> 0:20:56.920 And that's a negative feedback loop system. I'm just glad 0:20:56.920 --> 0:20:59.879 you've upgraded from that swamp cooler. I'm just glad I 0:21:00.119 --> 0:21:04.680 upgraded from opening up all the windows and shouting at people. Yeah. 0:21:04.680 --> 0:21:08.560 Your neighbors are happy with that. They are, uh yeah, 0:21:08.880 --> 0:21:11.120 yelled get off my lawn. But I live in an apartment, 0:21:11.160 --> 0:21:17.200 so it's awkward. Um yeah now uh yeah, now sorry 0:21:17.359 --> 0:21:21.760 I just said yeah now twice three times. Then okay. 0:21:21.760 --> 0:21:25.240 So negative feedback loops use a receptor, a control center, 0:21:25.280 --> 0:21:29.040 and an effector. Basically, a receptor is what's figuring out 0:21:29.080 --> 0:21:32.600 what's going on. It sends information to the control center. Um. 0:21:32.640 --> 0:21:34.320 And then the affect or is the thing that makes 0:21:34.359 --> 0:21:36.439 the change. So yeah, and the system in system of 0:21:36.440 --> 0:21:39.359 the autopilot we're talking about. The sensors are the receptor 0:21:39.880 --> 0:21:41.919 there are many different kinds in this case. Yes, the 0:21:41.960 --> 0:21:45.520 control the control center is the computer that takes in 0:21:45.560 --> 0:21:49.040 all this information, and the effector are the servo mechanisms 0:21:49.080 --> 0:21:52.639 that the computer sends commands to that then make adjustments 0:21:52.680 --> 0:21:56.679 to those control surfaces so that the plane does whatever 0:21:56.720 --> 0:21:59.720 it was the pilot wanted to do. And then these 0:22:00.040 --> 0:22:04.320 tims are incredibly sophisticated now to the point where, like 0:22:04.359 --> 0:22:07.399 I mentioned before, they can actually land a plane and 0:22:07.480 --> 0:22:11.159 sometimes are used to land a plane. Not not generally speaking. 0:22:11.200 --> 0:22:13.520 Most of the time it's a human pilot that's landing 0:22:13.520 --> 0:22:18.760 a plane. Yeah, but in cases where visibility is really limited, Uh, 0:22:18.800 --> 0:22:22.440 there are times where they they will they will incorporate 0:22:22.440 --> 0:22:25.000 an autopilot system in order to bring the plane in 0:22:25.080 --> 0:22:28.480 and land it when there's a fear that maybe human 0:22:28.520 --> 0:22:31.959 failure could play a role in a safe landing. So 0:22:32.000 --> 0:22:36.040 it's not common, but it can happen. Yeah, they prefer 0:22:36.160 --> 0:22:39.280 not to do that. Um, it's usually better too that 0:22:39.280 --> 0:22:42.119 that's not a time when you want, uh, the system 0:22:42.160 --> 0:22:45.680 to fail. It's it's usually a pretty a pretty dramatic 0:22:45.720 --> 0:22:49.600 turn of events for that to happen, because normally pilots 0:22:49.840 --> 0:22:54.600 don't bring planes into UH to UH to an airport 0:22:54.680 --> 0:22:57.240 where there's already that kind of limited visibility. If there, 0:22:57.359 --> 0:23:00.680 if they can help it, they'll usually divert to another. Really, 0:23:00.720 --> 0:23:03.199 air traffic control will tell them to divert, divert to 0:23:03.240 --> 0:23:07.880 another airport UH that they can get to safely, rather 0:23:07.960 --> 0:23:09.879 than go into an airport where there's going to be 0:23:09.960 --> 0:23:14.879 conditions that will severely limit visibility. Now that's not always possible. 0:23:14.920 --> 0:23:17.640 I mean in commercial flights that tends to happen quite 0:23:17.680 --> 0:23:20.399 a bit because you know the past, your safety is 0:23:20.440 --> 0:23:24.399 so important. But with something like a military flight, it 0:23:24.480 --> 0:23:29.439 may not be a possibility. So um, different cases, depending 0:23:29.440 --> 0:23:32.919 on the whole scenario there, but it is possible, and 0:23:32.960 --> 0:23:37.120 it has happened. I know we haven't really diverted from 0:23:37.119 --> 0:23:41.040