WEBVTT 1 00:00:00.120 --> 00:00:04.080 Picture this. It's June twenty fourth, nineteen eighty two. You're 2 00:00:04.120 --> 00:00:06.919 strapped into a window seat on British Airways flight nine. 3 00:00:07.120 --> 00:00:11.480 Oh Man. Yeah right, So it's pitch black outside. You 4 00:00:11.519 --> 00:00:14.960 are eleven thousand meters above the Indian Ocean, and suddenly 5 00:00:15.080 --> 00:00:19.399 this strange, shimmering white light begins to just cling to 6 00:00:19.480 --> 00:00:21.359 the wings outside your window, like. 7 00:00:21.320 --> 00:00:22.879 A glowing web of electricity. 8 00:00:22.879 --> 00:00:24.760 Basically, it's wrapping around the metal. 9 00:00:24.960 --> 00:00:27.760 And you know that actually resembles Saint almost fire, which 10 00:00:27.800 --> 00:00:31.600 is a totally known electrical phenomenon in aviation, right, But 11 00:00:31.679 --> 00:00:34.520 the thing is, Saint Almo's fire usually only happens when 12 00:00:34.560 --> 00:00:37.159 a plane flies through highly charged. 13 00:00:36.799 --> 00:00:38.560 Thunderclouds, which they weren't in. 14 00:00:38.880 --> 00:00:41.759 Right on this specific night, the weather radar in the 15 00:00:41.759 --> 00:00:44.520 cockpit showing that the sky is perfectly clear, I mean, 16 00:00:44.560 --> 00:00:46.200 there isn't a cloud for miles. 17 00:00:46.280 --> 00:00:48.920 But the strangeness doesn't stop with the lights, so an 18 00:00:49.000 --> 00:00:53.320 acrid sulfuric smoke starts pouring through the cabin vents. You 19 00:00:53.359 --> 00:00:58.119 can see passengers sweating, rubbing their eyes, coughing into their sleeves, 20 00:00:58.359 --> 00:01:00.399 and then people look out the windows and see something 21 00:01:00.439 --> 00:01:04.239 straight out of a nightmare. Massive forty foot jets of 22 00:01:04.280 --> 00:01:06.599 flame are shooting out from the backs of the engines. 23 00:01:06.319 --> 00:01:08.120 Which is never what you want to see at eleven 24 00:01:08.159 --> 00:01:08.840 thousand meters. 25 00:01:08.920 --> 00:01:13.400 Never, the seven forty seven's huge rolls Royce engines suddenly 26 00:01:13.400 --> 00:01:17.599 make this grating, violent rumbling sound. It's described as sounding 27 00:01:17.640 --> 00:01:21.239 like a cement mixer churning a load of heavy rocks. Wow, 28 00:01:21.400 --> 00:01:23.480 and then just dead silence. In the span of a 29 00:01:23.519 --> 00:01:26.400 minute and a half, all four engines have completely failed. 30 00:01:26.519 --> 00:01:28.799 Yeah, a four engine flame out on a seven forty seven. 31 00:01:28.840 --> 00:01:31.079 At the time, that was the scenario no crew. 32 00:01:30.920 --> 00:01:33.239 Had ever trained for, really, none at all. 33 00:01:33.239 --> 00:01:37.079 None, because it was considered a statistical impossibility. I mean, 34 00:01:37.159 --> 00:01:40.439 these aircraft were highly advanced machines, but they were absolutely 35 00:01:40.480 --> 00:01:44.040 not designed to operate as three hundred ton gliders. 36 00:01:44.400 --> 00:01:47.719 Well, welcome to today's deep dive. Today we are opening 37 00:01:47.760 --> 00:01:52.359 up three extraordinary real life aviation investigation. 38 00:01:51.799 --> 00:01:53.719 Files and these are some wild ones. 39 00:01:53.719 --> 00:01:56.920 They really are. We're going to explore the invisible forces 40 00:01:56.959 --> 00:02:01.799 that bring massive, you know, technologically anst commercial jets to 41 00:02:01.879 --> 00:02:04.719 the absolute brink of disaster. We're going to look at 42 00:02:04.719 --> 00:02:07.280 the physics of the environment, the mechanics of the aircraft, 43 00:02:07.519 --> 00:02:10.159 and I think, most importantly the psychology of the human 44 00:02:10.199 --> 00:02:11.680 beings sitting right there in that. 45 00:02:11.680 --> 00:02:15.159 Cockpit, because when the machines fail, the human mind is 46 00:02:15.240 --> 00:02:17.599 always the ultimate fail safe. 47 00:02:17.479 --> 00:02:20.919 Or tragically, the final failure point exactly. 48 00:02:21.400 --> 00:02:25.439 It is a really profound tension. We build these modern 49 00:02:25.479 --> 00:02:28.759 marvels of engineering and they're packed with redundant safety systems, 50 00:02:29.240 --> 00:02:33.120 but the volatile environment they operate in, combined with the complex, 51 00:02:33.759 --> 00:02:37.039 sometimes fragile psychology of the humans flying them, well, it 52 00:02:37.080 --> 00:02:40.400 introduces variables that no computer can ever fully control. 53 00:02:40.560 --> 00:02:43.000 So let's put ourselves right inside that terrifying cockpit on 54 00:02:43.080 --> 00:02:46.360 British Airways Flight nine. You've got Captain Eric Moody, First 55 00:02:46.400 --> 00:02:50.120 Officer Roger Greaves, and flight Engineer Barry Toalny Freeman. 56 00:02:50.000 --> 00:02:53.560 Right, and they're suddenly sitting in a silent falling metal tube. 57 00:02:53.800 --> 00:02:57.080 It's falling. To understand the physics of their situation, you 58 00:02:57.159 --> 00:02:59.000 kind of have to look at the glide ratio right. 59 00:02:59.360 --> 00:03:02.719 Without an thrust, a seven hundred and forty seven drops 60 00:03:02.759 --> 00:03:06.439 about one kilometer for every fifteen kilometers it moves. 61 00:03:06.199 --> 00:03:09.280 Forward, so they are basically falling toward the pitch black 62 00:03:09.319 --> 00:03:10.039 ocean YEP. 63 00:03:10.159 --> 00:03:13.400 And to make matters even worse, the cabin begins losing pressure. 64 00:03:13.960 --> 00:03:17.039 The air at eleven thousand meters is just way too. 65 00:03:16.919 --> 00:03:20.080 Thin to breathe, and that loss of cabin pressure really 66 00:03:20.120 --> 00:03:24.039 forces their hand. They have to initiate a rapid, incredibly 67 00:03:24.120 --> 00:03:26.560 steep descent just to get the aircraft down to an 68 00:03:26.560 --> 00:03:30.400 altitude where the passengers don't lose consciousness. So they are 69 00:03:30.439 --> 00:03:34.800 trading their most valuable resource, which is altitude, for breathable air. 70 00:03:35.080 --> 00:03:37.520 While they are plunging in the dark, the crew snaps 71 00:03:37.520 --> 00:03:40.719 into their highly trained emergency mode. They start running the 72 00:03:40.759 --> 00:03:42.919 standard three minute engine restart. 73 00:03:42.599 --> 00:03:44.319 Drill, which is standard procedure. 74 00:03:44.599 --> 00:03:47.240 But think about the terrifying math here. Falling at their 75 00:03:47.280 --> 00:03:50.400 current rate of descent, they only have enough time to 76 00:03:50.479 --> 00:03:53.479 run that full three minute drill maybe eight or nine 77 00:03:53.479 --> 00:03:55.280 times before they hit the water. 78 00:03:55.599 --> 00:03:58.960 Yeah, and recognizing that the flight engineer actually starts shortening 79 00:03:59.000 --> 00:04:02.520 the drill, Yeah, he modifies the procedure on the fly 80 00:04:02.680 --> 00:04:05.759 to cycle through it faster. They attempt to restart those 81 00:04:05.800 --> 00:04:10.960 engines up to fifty times fifty times fifty and nothing catches. 82 00:04:11.199 --> 00:04:12.879 There is just zero thrust. 83 00:04:13.240 --> 00:04:16.439 This is where Captain Moody makes what has to be 84 00:04:16.600 --> 00:04:19.319 I mean, one of the most famously calm announcements in 85 00:04:19.360 --> 00:04:20.560 all of aviation history. 86 00:04:20.639 --> 00:04:21.439 It's legendary. 87 00:04:21.519 --> 00:04:24.720 It gets on the PA system and in this perfectly 88 00:04:24.720 --> 00:04:29.279 measured tone, says U, ladies and gentlemen, this is your 89 00:04:29.279 --> 00:04:32.360 captain speaking. We have a small problem. All four engines 90 00:04:32.360 --> 00:04:33.279 have stopped. 91 00:04:32.920 --> 00:04:34.079 A small problem, right. 92 00:04:34.120 --> 00:04:36.279 We are doing our damnedest to get it under control. 93 00:04:36.560 --> 00:04:38.399 I trust you are not in too much distress. 94 00:04:38.519 --> 00:04:40.879 I mean it is the absolute epitome of the stiff 95 00:04:40.920 --> 00:04:43.839 upper lip, truly, But inside the cockpit the reality is 96 00:04:43.920 --> 00:04:47.879 just devastating. A jagged mountain range blocks their path to 97 00:04:47.920 --> 00:04:51.439 the nearest airport in Jakarta, and they're dropping fast, exactly 98 00:04:51.720 --> 00:04:54.079 at their current rate of descent, they simply won't clear 99 00:04:54.120 --> 00:04:56.800 the peaks. The captain has to make the brutal decision 100 00:04:56.800 --> 00:04:59.720 to turn the plane around and actually prepare to ditch 101 00:04:59.759 --> 00:05:01.920 into the pitch black, open ocean. 102 00:05:01.680 --> 00:05:04.879 Which is insane. Ditching a heavy jet at night is 103 00:05:04.920 --> 00:05:07.920 a maneuver that is incredibly dangerous, even when you have 104 00:05:08.000 --> 00:05:10.040 engine power, you know to control your descent. 105 00:05:10.160 --> 00:05:14.160 Oh absolutely, Doing it in a glider is almost certainly fatal. 106 00:05:14.240 --> 00:05:17.600 But then just as they drop past four thousand meters, 107 00:05:17.879 --> 00:05:21.959 preparing for impact, a miracle happens. The number four engine 108 00:05:22.040 --> 00:05:25.399 suddenly roars back to life, thank goodness, then number three, 109 00:05:25.439 --> 00:05:29.160 then one in two, all four engines come back online. 110 00:05:29.199 --> 00:05:30.240 It's unbelievable. 111 00:05:30.279 --> 00:05:32.879 They have just enough power to climb back up, clear 112 00:05:32.920 --> 00:05:36.639 the mountains and divert to Jakarta. But the nightmare isn't 113 00:05:36.639 --> 00:05:38.959 even over, not at all. As they approach the runway, 114 00:05:39.279 --> 00:05:42.720 those strange shimmering lights return. One of the engines starts 115 00:05:42.800 --> 00:05:45.720 violently surging and has to be shut down again, and 116 00:05:45.759 --> 00:05:47.920 the pilots realize they can't even see out the window. 117 00:05:48.079 --> 00:05:50.360 Yeah, the windshield is completely opaque. 118 00:05:50.040 --> 00:05:52.120 Like someone painted over it exactly. 119 00:05:52.240 --> 00:05:55.759 The glass had been essentially sand blasted. And to compound 120 00:05:55.759 --> 00:05:58.560 the terror, the ground equipment and Jakarta that provides the 121 00:05:58.639 --> 00:06:01.600 instrument glide path, the electronic beam that tells them their 122 00:06:01.600 --> 00:06:04.040 angle of descent is completely broken. 123 00:06:04.279 --> 00:06:05.120 Are you kidding me? 124 00:06:05.360 --> 00:06:08.879 I know they have to land this crippled, mostly blind 125 00:06:08.959 --> 00:06:12.480 seven forty seven manually. They're peering out of a tiny 126 00:06:12.560 --> 00:06:15.639 two inch sliver of side window that hadn't been scratched. 127 00:06:15.879 --> 00:06:17.560 That is just wild, and. 128 00:06:17.480 --> 00:06:19.800 Miraculously they do it. They grease the landing. 129 00:06:19.920 --> 00:06:22.959 It's a legendary piece of flying. Yeah, but this brings 130 00:06:23.040 --> 00:06:24.879 us to the core mystery of this whole deep. 131 00:06:24.680 --> 00:06:27.959 Dive, right, the why how does a perfectly. 132 00:06:27.519 --> 00:06:31.240 Healthy seven forty seven lose all four engines simultaneously. I 133 00:06:31.279 --> 00:06:34.279 remember reading the source material and thinking about the weather radar. 134 00:06:34.519 --> 00:06:34.920 Uh huh. 135 00:06:34.920 --> 00:06:37.920 They checked it. It was completely clear. So how can 136 00:06:37.920 --> 00:06:41.480 a force powerful enough to destroy four jet engines be 137 00:06:41.639 --> 00:06:42.519 totally invisible? 138 00:06:42.600 --> 00:06:45.360 Well, the answer lies in understanding the physics of what 139 00:06:45.439 --> 00:06:48.639 aircraft weather radar actually does. H Okay, it is designed to 140 00:06:48.680 --> 00:06:53.199 bounce radio waves off of moisture. It looks for water droplets, rain, hail, 141 00:06:53.360 --> 00:06:53.800 or snow. 142 00:06:54.279 --> 00:06:56.839 But the culprit here wasn't water exactly. 143 00:06:56.959 --> 00:07:00.120 The culprit that brought down flight lane was completely bone dry. 144 00:07:00.199 --> 00:07:04.000 It was Mount Gollongung, a massive volcano in Indonesia, had 145 00:07:04.120 --> 00:07:08.279 erupted just hours earlier, sending an enormous dense cloud of 146 00:07:08.399 --> 00:07:12.720 pulverized rock and volcanic ash fifteen thousand meters. 147 00:07:12.399 --> 00:07:14.720 Into the night sky, straight into their path. 148 00:07:14.519 --> 00:07:16.360 Drifting directly into their flight path. 149 00:07:16.519 --> 00:07:20.319 So, because the ash is just dry, microscopic ground up rock, 150 00:07:20.800 --> 00:07:22.519 the radarways just pass right through it. 151 00:07:22.680 --> 00:07:25.000 Right, It doesn't reflect a signal back to the cockpit 152 00:07:25.040 --> 00:07:25.600 at all. 153 00:07:25.680 --> 00:07:27.600 It is a literal invisible. 154 00:07:27.120 --> 00:07:30.959 Trap precisely, and that invisible dry rock explains every single 155 00:07:31.079 --> 00:07:33.199 terrifying thing the passengers and crew. 156 00:07:33.000 --> 00:07:34.720 Experienced, like the glowing lights. 157 00:07:34.839 --> 00:07:37.839 Yes, when you force a massive aluminum airplane through a 158 00:07:37.839 --> 00:07:41.120 cloud of highly abrasive dust at five hundred miles per hour, 159 00:07:41.480 --> 00:07:43.920 the friction strips electrons off the airframe. 160 00:07:44.079 --> 00:07:44.920 Oh wow, it. 161 00:07:44.879 --> 00:07:49.040 Creates intense localized static electricity. Yeah, that was the glowing 162 00:07:49.079 --> 00:07:51.800 web of Saint Elmo's fire on the wings. The abrasive 163 00:07:51.879 --> 00:07:54.279 rock also sand blasted the paint right off the nose 164 00:07:54.279 --> 00:07:57.040 of the plane and scratched the windshield glass totally. 165 00:07:56.759 --> 00:07:59.879 Opig and the sulfur smell in the cabin. That makes 166 00:07:59.879 --> 00:08:02.600 it almost sense. Now, it wasn't an electrical fire on 167 00:08:02.639 --> 00:08:05.759 the plane. It was actual volcanic gas bleeding into the 168 00:08:05.800 --> 00:08:10.000 air vents exactly. But let's look at the engines. How 169 00:08:10.040 --> 00:08:14.959 does dry dust choke out four massive jet engines? I mean, 170 00:08:15.399 --> 00:08:17.800 they're built to handle extreme conditions. 171 00:08:17.279 --> 00:08:19.399 They are, But we have to look at the thermodynamics 172 00:08:19.399 --> 00:08:22.000 of a jet turbine. A jet engine sucks in massive 173 00:08:22.000 --> 00:08:25.319 amounts of air, compresses it mixes it with aviation fuel 174 00:08:25.560 --> 00:08:28.720 and ignites it. Right, The combustion chamber inside that engine 175 00:08:28.800 --> 00:08:32.559 operates at around two thousand degrees celsius. Okay, Volcanic ash 176 00:08:32.639 --> 00:08:35.720 being pulverized rock has a melting point of about thirteen 177 00:08:35.799 --> 00:08:36.480 hundred degrees. 178 00:08:36.639 --> 00:08:39.720 Oh wow. Wait, So as the engines are inhaling millions 179 00:08:39.720 --> 00:08:42.960 of cubic feet of this ash, the rock is literally 180 00:08:43.000 --> 00:08:44.559 melting inside the engine core. 181 00:08:44.720 --> 00:08:48.840 Yes, it melted into a sticky molten glasslight goo. 182 00:08:49.120 --> 00:08:49.919 That's horrifying. 183 00:08:50.039 --> 00:08:52.799 It is this goo coated the turbine blades and the 184 00:08:52.799 --> 00:08:55.960 inside of the combustion chamber, which just violently disrupted the 185 00:08:56.000 --> 00:08:57.200 delicate aerodynamics of. 186 00:08:57.120 --> 00:08:58.799 The airflow, and that caused the flames. 187 00:08:59.080 --> 00:09:03.000 Yeah, that disrupts and cause massive compressor stalls and backfires. 188 00:09:03.279 --> 00:09:07.720 Those forty foot flames the passenger saw shooting out the back. Eventually, 189 00:09:07.720 --> 00:09:11.320 the molten rock choked off the airflow, entirely starving the 190 00:09:11.360 --> 00:09:13.559 engines of oxygen and causing them to flame out. 191 00:09:13.799 --> 00:09:17.600 The wildest part of this whole sequence to me, isn't 192 00:09:17.600 --> 00:09:21.000 that the engines stopped. It's that they restarted at all. 193 00:09:21.159 --> 00:09:23.279 It's a crazy piece of physics. 194 00:09:23.799 --> 00:09:27.039 Because think about what happens when the engines die the 195 00:09:27.080 --> 00:09:31.679 fire goes out, the combustion chamber rapidly cools down, and 196 00:09:31.720 --> 00:09:33.879 as the plane is gliding you know, falling out of 197 00:09:33.919 --> 00:09:36.879 the sky, it eventually drops below the bottom layer of 198 00:09:36.919 --> 00:09:39.840 the ash cloud into clean air, exact so that molten 199 00:09:39.879 --> 00:09:43.639 goo cools down, hardens back into a brittle glass like shell, 200 00:09:44.080 --> 00:09:46.639 and the sheer force of the cold air rushing through 201 00:09:46.639 --> 00:09:49.519 those dead gliding engines just shatters the rock. 202 00:09:49.639 --> 00:09:50.480 It chips right off. 203 00:09:50.519 --> 00:09:51.840 It chips off and blows out the back. 204 00:09:51.919 --> 00:09:54.639 That is the incredible twist of chemistry and physics that 205 00:09:54.720 --> 00:09:57.480 saved their lives. The engine essentially had to die in 206 00:09:57.559 --> 00:09:58.559 order to heal itself. 207 00:09:58.639 --> 00:09:59.480 It is so wild. 208 00:10:00.000 --> 00:10:02.399 Since the brittle rock was cleared out by the rushing air, 209 00:10:02.759 --> 00:10:06.279 the crew's frantic restart drills finally caught a spark and 210 00:10:06.320 --> 00:10:07.320 the fuel ignited. 211 00:10:07.759 --> 00:10:10.519 Man. So Flight nine is this perfect example of a 212 00:10:11.000 --> 00:10:14.840 crew overcoming a total mechanical failure caused by an invisible 213 00:10:14.840 --> 00:10:18.639 external environment. But what happens when the outside environment is 214 00:10:18.679 --> 00:10:22.919 perfectly safe, but the invisible threat is actually inside the cockpit, 215 00:10:23.639 --> 00:10:26.159 specifically inside the pilot's own brain. 216 00:10:26.320 --> 00:10:29.039 Yeah, this is where we cross into a highly treacherous 217 00:10:29.039 --> 00:10:32.000 intersection of human physiology and automated technology. 218 00:10:32.039 --> 00:10:35.120 Let's set the scene for February nineteenth, nineteen eighty five. 219 00:10:35.919 --> 00:10:39.759 A China Airline seven forty seven flight Zeozer six is 220 00:10:39.840 --> 00:10:42.240 cruising over the Pacific Ocean at forty one thousand feet 221 00:10:42.320 --> 00:10:44.799 middle of the night, pitch black again. It's a totally 222 00:10:44.879 --> 00:10:47.879 routine flight until the number four engine, the one on 223 00:10:47.919 --> 00:10:50.720 the far right wing, starts giving them weak thrust. 224 00:10:50.799 --> 00:10:52.879 Just weak thrust, not even a total failure, right, It's. 225 00:10:52.799 --> 00:10:55.159 Not a catastrophic failure at first, just a gradual loss 226 00:10:55.200 --> 00:10:58.240 of power. The crew tries to reignite the engine, but 227 00:10:58.279 --> 00:11:00.279 they're too high up. The air is too in for 228 00:11:00.320 --> 00:11:03.440 a relight. Yeah. But while they are hyper fixated on 229 00:11:03.679 --> 00:11:06.840 troubleshooting this one engine, the plane begins to bank to 230 00:11:06.879 --> 00:11:10.360 the right, It slows down, it stalls, and suddenly it 231 00:11:10.480 --> 00:11:11.799 just tumbles out of the sky. 232 00:11:12.039 --> 00:11:16.480 They enter an uncontrolled vertical dive from forty one thousand. 233 00:11:16.120 --> 00:11:17.519 Feet from a weak engine. 234 00:11:17.679 --> 00:11:21.000 Exactly to understand how a weak engine leads to a 235 00:11:21.080 --> 00:11:23.320 vertical dive, we have to look at the physics of 236 00:11:23.399 --> 00:11:24.559 asymmetric thrust. 237 00:11:24.799 --> 00:11:26.080 Okay, break that down for us. 238 00:11:26.159 --> 00:11:28.559 So when you lose power on the right side, the 239 00:11:28.600 --> 00:11:31.440 engines on the left are still pushing at full cruising power. 240 00:11:31.519 --> 00:11:35.120 Right right, that offset thrust vector causes the plane to 241 00:11:35.360 --> 00:11:39.279 yaw or twist to the right. The correct manual response 242 00:11:39.360 --> 00:11:41.440 is for the pilot to step heavily on the left 243 00:11:41.480 --> 00:11:44.720 rudder pedal to counteract that twisting force and keep the 244 00:11:44.759 --> 00:11:45.720 nose pointed straight. 245 00:11:45.919 --> 00:11:48.360 But the captain didn't step on the rudder. He left 246 00:11:48.360 --> 00:11:52.799 the autopilot engaged, assuming the computer would handle the imbalance. 247 00:11:52.480 --> 00:11:55.279 And that brings us to a phenomenon investigators called the 248 00:11:55.360 --> 00:11:56.639 automation illusion. 249 00:11:56.960 --> 00:11:58.000 Automation illusion. 250 00:11:58.080 --> 00:12:00.279 Yeah, we have to remember this is nineteen eighty five. 251 00:12:00.440 --> 00:12:03.519 The autopilot systems on those seven forty sevens were advanced, 252 00:12:03.919 --> 00:12:06.519 but they had a very specific limitation, which would the 253 00:12:06.600 --> 00:12:10.320 autopilot did not have a physical connection to the rudder pedals. 254 00:12:10.759 --> 00:12:14.200 It only controlled the ailerons the small flaps on the 255 00:12:14.279 --> 00:12:17.080 trailing edge of the wings wow wow, and the ailerons 256 00:12:17.120 --> 00:12:21.159 simply didn't have enough aerodynamic authority to stop a three 257 00:12:21.240 --> 00:12:24.879 hundred ton aircraft from rolling over when pushed by that 258 00:12:24.960 --> 00:12:26.120 asymmetric thrust. 259 00:12:26.200 --> 00:12:28.840 So the captain assumed the automation was flying the plane 260 00:12:28.840 --> 00:12:29.759 the way human. 261 00:12:29.519 --> 00:12:31.759 Would, and it absolutely wasn't. 262 00:12:31.600 --> 00:12:35.120 The plane is slowly rolling onto its back. You might 263 00:12:35.159 --> 00:12:39.639 wonder they have attitude indicators right the artificial horizon gauges 264 00:12:39.759 --> 00:12:42.240 glowing right in front of their faces. 265 00:12:42.000 --> 00:12:43.279 Right there on the dashboard. 266 00:12:43.480 --> 00:12:45.840 Why did they just look at the instruments, see the 267 00:12:45.879 --> 00:12:47.799 plane banking and correct it. 268 00:12:47.960 --> 00:12:49.919 This is where the human physiology comes in. 269 00:12:50.240 --> 00:12:52.360 I always think about this feeling like being in an 270 00:12:52.360 --> 00:12:54.639 office chair in a pitch black room. 271 00:12:54.759 --> 00:12:56.039 Oh, that's a good way to put it. 272 00:12:56.200 --> 00:12:58.679 Yeah, Like if someone spins your chair around for thirty 273 00:12:58.679 --> 00:13:01.840 seconds and then suddenly stops, Your body still feels like 274 00:13:01.879 --> 00:13:03.480 it's spinning, but in the opposite direction. 275 00:13:03.679 --> 00:13:04.200 Exactly. 276 00:13:04.240 --> 00:13:06.720 If you try to stand up, you'll fall right over. Yeah, 277 00:13:06.840 --> 00:13:10.000 that is exactly what was happening to these pilots. 278 00:13:10.440 --> 00:13:14.240 That office chair analogy is the perfect way to understand 279 00:13:14.360 --> 00:13:15.679 spatial disorientation. 280 00:13:16.159 --> 00:13:17.480 Tell us about the biology of that. 281 00:13:17.960 --> 00:13:23.480 So the biology behind it involves your vestibular system, specifically 282 00:13:23.480 --> 00:13:27.720 the fluid inside the semicircular canals in your inner ear. Okay, 283 00:13:27.879 --> 00:13:30.080 when you are flying through thick clouds in the middle 284 00:13:30.120 --> 00:13:33.879 of the night, you have no external visual cues, no stars, 285 00:13:33.960 --> 00:13:35.799 no moon, no horizon. 286 00:13:35.399 --> 00:13:36.559 In darkness, just black. 287 00:13:37.159 --> 00:13:40.480 Your brain relies entirely on the fluid in those canals 288 00:13:40.480 --> 00:13:42.080 to tell you which way is up and whether you 289 00:13:42.120 --> 00:13:42.600 are turning. 290 00:13:42.879 --> 00:13:45.080 But the fluid lies to you profoundly. 291 00:13:45.879 --> 00:13:49.480 When an aircraft enters a slow, gradual bank like the 292 00:13:49.600 --> 00:13:52.840 China Airlines seven forty seven, did the fluid in your 293 00:13:52.879 --> 00:13:55.440 inner ear eventually catches up to the motion and settles. 294 00:13:55.559 --> 00:13:58.759 Oh man, your brain interprets that settled fluid is flying 295 00:13:58.840 --> 00:14:01.759 straight and level. When the plane suddenly drops into a 296 00:14:01.759 --> 00:14:06.159 steep dive, the changing g forces confused the vestibular system completely. 297 00:14:06.639 --> 00:14:08.840 Their bodies were screaming at them that they were flying 298 00:14:08.879 --> 00:14:11.480 relatively straight, maybe just a little turbulent. 299 00:14:11.120 --> 00:14:14.039 But their attitude indicators were showing them entering an extreme 300 00:14:14.399 --> 00:14:15.120 vertical role. 301 00:14:15.279 --> 00:14:15.600 Yes. 302 00:14:15.720 --> 00:14:19.120 Because the crew was entirely fixated on the engine problem, 303 00:14:19.519 --> 00:14:23.200 they just lost their situational awareness. They stopped scanning their other. 304 00:14:23.080 --> 00:14:24.960 Instruments, which is a classic mistake. 305 00:14:25.159 --> 00:14:27.720 When the captain finally did look at the attitude indicator, 306 00:14:27.799 --> 00:14:30.639 this reading was so extreme, I mean, showing the plane 307 00:14:30.679 --> 00:14:33.759 essentially upside down and plummeting. He assumed the instrument itself 308 00:14:33.759 --> 00:14:35.200 had suffered a mechanical failure. 309 00:14:35.360 --> 00:14:39.039 He trusted his lying inner ear over the literal gyroscope 310 00:14:39.080 --> 00:14:39.960 in front of him. 311 00:14:40.200 --> 00:14:41.480 That is terrifying. 312 00:14:41.679 --> 00:14:45.919 And the investigation uncovered another compounding biological factor, which was 313 00:14:46.360 --> 00:14:47.600 severe fatigue. 314 00:14:47.600 --> 00:14:47.879 Ah. 315 00:14:48.200 --> 00:14:51.519 Correct. The National Transportation Safety Board looked closely at the 316 00:14:51.600 --> 00:14:56.159 crew's circadian rhythms. The captain had crossed eighteen time zones 317 00:14:56.200 --> 00:14:59.879 in six days eighteen Yeah, his body clock was essentially 318 00:14:59.879 --> 00:15:02.480 a at two zero am. He was in the deepest 319 00:15:02.519 --> 00:15:04.679 trough of his biological sleep cycle. 320 00:15:04.519 --> 00:15:06.759 Which ruins your focus exactly. 321 00:15:07.240 --> 00:15:11.559 That profound level of fatigue physically impairs your cognitive bandwidth. 322 00:15:11.960 --> 00:15:14.879 It narrows your focus, making you hyper fixate on one 323 00:15:14.919 --> 00:15:18.720 minor problem like a weak engine, while completely missing the 324 00:15:18.759 --> 00:15:21.600 catastrophic fact that your airplane is flipping upside down. 325 00:15:21.919 --> 00:15:24.639 The descriptions from the passengers during this dive are just, 326 00:15:25.080 --> 00:15:26.519 I mean, pure nightmare fuel. 327 00:15:26.600 --> 00:15:27.679 It had to be horrific. 328 00:15:27.879 --> 00:15:29.919 They are falling out of the sky at mock speed. 329 00:15:30.679 --> 00:15:33.720 The g forces are so intense, peaking at five times 330 00:15:33.799 --> 00:15:36.960 normal gravity, that passengers felt like they weighed over one 331 00:15:36.960 --> 00:15:38.320 thousand pounds. 332 00:15:38.080 --> 00:15:40.039 Five g's in a commercial airliner. 333 00:15:40.120 --> 00:15:42.159 Yeah, people who weren't buckled in just popped up and 334 00:15:42.200 --> 00:15:45.200 were pinned to the ceiling. One passenger described looking at 335 00:15:45.240 --> 00:15:48.240 an older gentleman across the aisle and the g forces 336 00:15:48.240 --> 00:15:50.840 were so strong that his face was pulled back and 337 00:15:50.879 --> 00:15:53.840 contorted quote like he was lying on his side in 338 00:15:53.879 --> 00:15:55.480 a wax museum in a fire. 339 00:15:55.720 --> 00:15:57.120 Oh my god. 340 00:15:57.279 --> 00:15:59.799 The plane drops thirty thousand feet in just over a 341 00:15:59.799 --> 00:16:04.200 mint in the sheer speed, in aerodynamic stress, literally rip 342 00:16:04.279 --> 00:16:06.519 the landing gear doors off the bottom of the plane. 343 00:16:06.559 --> 00:16:09.840 The plane is basically disintegrating. But then at ninety five 344 00:16:09.919 --> 00:16:12.240 hundred feet they break through the bottom of the cloud deck. 345 00:16:12.240 --> 00:16:15.120 And that is the moment everything changes, because the second 346 00:16:15.159 --> 00:16:17.600 they pop out of the clouds, the captain sees the 347 00:16:17.679 --> 00:16:20.039 visual horizon line of the actual. 348 00:16:19.720 --> 00:16:21.360 Ocean, a true visual queue. 349 00:16:21.720 --> 00:16:27.399 Yes, his brain instantly recalibrates the visual data overrides the 350 00:16:27.519 --> 00:16:30.840 lying fluid in his inner ear. He realizes the instruments 351 00:16:30.840 --> 00:16:34.320 were right all along. Wrestles. The plane level pulls out 352 00:16:34.320 --> 00:16:37.080 of the dive with a severely damaged tail and links 353 00:16:37.120 --> 00:16:37.919 to San Francisco. 354 00:16:38.080 --> 00:16:40.000 It's amazing the wings didn't snap off. 355 00:16:39.919 --> 00:16:43.320 Truly with China Airlines, the captain's brain was lying to him, 356 00:16:43.480 --> 00:16:46.799 but the moment he saw the visual horizon, his instincts 357 00:16:46.840 --> 00:16:49.679 snap back and he saved the plane, right, But imagine 358 00:16:49.720 --> 00:16:52.080 being in a situation where the clouds never break. There's 359 00:16:52.120 --> 00:16:54.559 no horizon to save you. Yeah, the only thing that 360 00:16:54.600 --> 00:16:57.360 can prevent a crash is the pilot sitting right next 361 00:16:57.399 --> 00:17:00.279 to you. But the social dynamics in the cockpit actively 362 00:17:00.320 --> 00:17:01.480 prevent them from speaking up. 363 00:17:01.559 --> 00:17:03.559 And this brings us to a tragedy that forced the 364 00:17:03.600 --> 00:17:07.559 aviation industry to completely rethink the sociology of a cockpit 365 00:17:07.640 --> 00:17:10.880 right through a concept known as crew resource management or CRM. 366 00:17:11.039 --> 00:17:14.480 It's January third, two thousand and four, Charmelai Shake, Egypt. 367 00:17:15.079 --> 00:17:17.440 A flash Airline seven thirty seven is taking off at 368 00:17:17.480 --> 00:17:20.319 five zero am, again middle of the night. Once again 369 00:17:20.599 --> 00:17:23.920 it is a pitch black, moonless night. Yeah, but this 370 00:17:24.079 --> 00:17:27.440 time they are taking off directly over the Red Sea. 371 00:17:28.319 --> 00:17:31.160 So outside the window there isn't just a lack of stars, 372 00:17:31.440 --> 00:17:35.119 it is an absolute void of darkness. The water blends 373 00:17:35.160 --> 00:17:35.920 perfectly with the. 374 00:17:35.839 --> 00:17:37.880 Sky, no visual horizon at all. 375 00:17:38.039 --> 00:17:41.799 None. In the left seat, you have Captain Kudar Abdullah, 376 00:17:42.039 --> 00:17:45.920 a highly decorated military war hero with thousands of hours 377 00:17:45.920 --> 00:17:49.079 of flight time, very experienced, very In the right seat, 378 00:17:49.200 --> 00:17:53.680 first Officer Amer Alshaffi, who is decades younger. He's essentially 379 00:17:53.799 --> 00:17:55.119 young enough to be the captain's son. 380 00:17:55.240 --> 00:17:59.279 And historically commercial aviation drew really heavily from the military. 381 00:17:59.400 --> 00:18:03.720 Right the dynamic, it created cockpits with very steep authority gradients. 382 00:18:03.799 --> 00:18:06.480 The captain was viewed as an infallible commander, you know, 383 00:18:06.519 --> 00:18:08.480 and the co pilot was expected to be a silent 384 00:18:08.519 --> 00:18:10.039 subort in it. Just do what you're told. 385 00:18:10.240 --> 00:18:13.240 That dynamic is completely critical here. The flight plan for 386 00:18:13.279 --> 00:18:16.240 Flash Airlines calls for a climbing left turn to head 387 00:18:16.240 --> 00:18:19.279 toward Cairo, left turn right, But shortly after takeoff, instead 388 00:18:19.279 --> 00:18:23.400 of banking left, the plane begins a slow creeping right bank. 389 00:18:23.519 --> 00:18:26.000 Just like the China Airlines flight exactly. 390 00:18:26.599 --> 00:18:30.640 The captain, likely experiencing the exact same spatial disorientation we 391 00:18:30.720 --> 00:18:34.200 just talked about, is inadvertently steering the plane into a spiral. 392 00:18:34.799 --> 00:18:37.200 It rolls tighter and tighter, the nose drops, and the 393 00:18:37.200 --> 00:18:38.680 plane plunges into a. 394 00:18:38.599 --> 00:18:39.839 Dive and they don't pull out. 395 00:18:40.039 --> 00:18:42.599 No. It hits the Red Sea. It's seven hundred kilometers 396 00:18:42.640 --> 00:18:45.720 per hour. All one hundred and forty eight people on board, 397 00:18:45.960 --> 00:18:50.319 mostly vacationing families, are killed instantly. It's just awful there's 398 00:18:50.359 --> 00:18:53.920 a deeply heartbreaking detail from the recovery effort. Investigators found 399 00:18:53.920 --> 00:18:57.079 a passenger's postcard floating in the debris that simply read 400 00:18:57.519 --> 00:18:59.359 I think this card will arrive after me. 401 00:19:00.200 --> 00:19:01.160