WEBVTT 1 00:00:00.120 --> 00:00:04.040 Picture this. I want to completely transport you to a dark, 2 00:00:04.440 --> 00:00:08.439 rain soaked evening. It's July of two thousand and seven. 3 00:00:08.320 --> 00:00:09.039 Right the dead of winter. 4 00:00:09.119 --> 00:00:12.599 Down there, exactly, you are looking down at the sprawling 5 00:00:12.800 --> 00:00:16.519 concrete metropolis of some Paula, Brazil. The city is just 6 00:00:16.600 --> 00:00:22.039 shrouded in these heavy, relentless downpours that snarl traffic for miles, 7 00:00:22.359 --> 00:00:25.559 it really is. And high above all of this urban chaos, 8 00:00:25.879 --> 00:00:28.879 you have one hundred and eighty one passengers sitting in 9 00:00:28.920 --> 00:00:31.760 the cabin of a routine domestic flight. They're probably reading, 10 00:00:32.000 --> 00:00:35.679 maybe sleeping, totally unaware, completely unaware that they are about 11 00:00:35.679 --> 00:00:39.240 to descend into one of the most notoriously treacherous landing 12 00:00:39.240 --> 00:00:40.399 strips on planet Earth. 13 00:00:40.439 --> 00:00:42.920 It is a terrifying just a position when you really 14 00:00:42.920 --> 00:00:45.600 think about it. Inside that cabin, it's just another Tuesday 15 00:00:45.600 --> 00:00:48.679 commuting flight. Yeah, coffee cups are being cleared away, seat 16 00:00:48.679 --> 00:00:52.560 belts are being fastened. But outside the window, the environmental 17 00:00:52.560 --> 00:00:56.399 conditions and mechanical realities are aligning to create this perfect 18 00:00:56.600 --> 00:00:57.560 deadly storm. 19 00:00:57.799 --> 00:01:02.920 Right and looking at the massive stack of NTSB telemetry reports, 20 00:01:02.960 --> 00:01:07.319 aviation safety articles, and the psychological analyzes you sent over 21 00:01:07.359 --> 00:01:10.920 to us, our mission for this deep dive is super clear. 22 00:01:11.120 --> 00:01:11.680 Definitely. 23 00:01:12.120 --> 00:01:16.439 Today we are stepping into the boots of aviation accident investigators. 24 00:01:17.040 --> 00:01:20.120 Using the specific flight data, cockpit voice transcripts, and ground 25 00:01:20.159 --> 00:01:23.760 reports you provided, we are going to reconstruct the harrowing 26 00:01:23.840 --> 00:01:27.120 true story of tam Airline's flight thirty fifty four. 27 00:01:27.439 --> 00:01:28.760 It's a heavy one, it is. 28 00:01:29.079 --> 00:01:32.280 Our goal is to figure out the exact mechanisms, both 29 00:01:32.359 --> 00:01:37.079 mechanical and psychological, that transformed a totally routine flight into 30 00:01:37.159 --> 00:01:40.400 the deadliest aviation disaster in South American history. 31 00:01:40.560 --> 00:01:42.319 And looking through the research you shared with us, it's 32 00:01:42.359 --> 00:01:44.159 just obvious we have to approach this not just as 33 00:01:44.200 --> 00:01:47.239 engineers examining bat metal, but as human beings trying to 34 00:01:47.319 --> 00:01:48.959 understand the fragility of the human mind. 35 00:01:49.040 --> 00:01:51.799 Yeah, that human element is key, because ultimately the data 36 00:01:51.840 --> 00:01:54.280 you compiled reveals that this isn't simply a story about 37 00:01:54.280 --> 00:01:55.159 failing machines. 38 00:01:55.560 --> 00:01:58.560 It's a profound look into what happens to human cognition 39 00:01:58.599 --> 00:02:02.359 and motor function when least under just extreme suffocating pressure. 40 00:02:02.599 --> 00:02:05.079 So let's start with the geography, because going through the 41 00:02:05.079 --> 00:02:10.080 airport's schematics you provided, Congoana's airport is a pilot's absolute nightmare. 42 00:02:10.159 --> 00:02:10.319 Oh. 43 00:02:10.400 --> 00:02:14.439 Absolutely, it's not out in the quiet flat suburbs. Congoana's 44 00:02:14.479 --> 00:02:18.000 is jammed right into the densely packed, beating heart of Sompollo. 45 00:02:18.439 --> 00:02:21.800 It is crowded on all sides by high rise apartment buildings, 46 00:02:21.919 --> 00:02:23.439 office blocks, busy. 47 00:02:23.240 --> 00:02:25.400 Roadways, just surrounded by hazards. 48 00:02:25.680 --> 00:02:28.840 Yeah. And the specific runway flight three L four is 49 00:02:28.840 --> 00:02:32.319 aiming for runway three five L is less than two 50 00:02:32.400 --> 00:02:35.520 thousand meters long, which is incredibly short for a large 51 00:02:35.560 --> 00:02:38.360 airbus A three twenty very short. But worse than the 52 00:02:38.439 --> 00:02:41.520 length is the topography. It's essentially built on a hilltop 53 00:02:41.599 --> 00:02:44.280 with these sharp, unforgiving drop offs on all sides. 54 00:02:44.439 --> 00:02:47.080 I mean, it's practically a concrete strip on a cliff 55 00:02:47.120 --> 00:02:48.360 in the middle of a massive city. 56 00:02:48.479 --> 00:02:48.680 Right. 57 00:02:48.840 --> 00:02:50.680 To give you a sense of its reputation among the 58 00:02:50.680 --> 00:02:53.879 people who actually fly these planes, your notes included a 59 00:02:53.960 --> 00:02:57.080 quote from Captain Carlos Camacho. He's the flight safety director 60 00:02:57.120 --> 00:02:58.560 of the Brazilian Pilots Union. 61 00:02:58.599 --> 00:02:59.319 What did he say? 62 00:02:59.400 --> 00:03:03.039 He compared landing at Congana's to landing on an aircraft carrier. 63 00:03:03.680 --> 00:03:05.680 The margin for air is effectively zero. 64 00:03:05.840 --> 00:03:07.599 Wow, an aircraft carrier. 65 00:03:08.039 --> 00:03:10.560 Yeah. In fact, just the day prior to our story. 66 00:03:11.000 --> 00:03:14.159 A commuter plane actually spun out of control while landing. 67 00:03:13.879 --> 00:03:14.879 There just the day before. 68 00:03:14.960 --> 00:03:17.280 The day before, and a few months prior to that, 69 00:03:17.680 --> 00:03:20.560 a Boeing seven thirty seven came skidding to a stop 70 00:03:21.000 --> 00:03:24.479 literally inches before tumbling down that steep embankment at the 71 00:03:24.560 --> 00:03:25.280 end of the runway. 72 00:03:25.360 --> 00:03:28.599 Okay, so knowing that history, every pilot knows this runway 73 00:03:28.599 --> 00:03:32.759 as a monster, and into this environment flies TAM three 74 00:03:32.960 --> 00:03:36.280 zero five to four, arriving from Portal Allegri. Right now, 75 00:03:36.360 --> 00:03:38.840 in the cockpit, we do not have rookies. We have 76 00:03:38.960 --> 00:03:43.439 two highly experienced airmen. Captain Henrique Stefani Desaco has over 77 00:03:43.560 --> 00:03:46.039 thirteen thousand, six hundred flight hours. 78 00:03:46.199 --> 00:03:48.719 That's a massive amount of experience, it really is. 79 00:03:49.000 --> 00:03:52.319 And his first officer, Kleiber Lima, has over fourteen thy 80 00:03:52.400 --> 00:03:55.840 seven hundred hours. These guys are absolute veterans. But okay, 81 00:03:55.919 --> 00:03:58.120 let's unpack this because when you sent us the maintenance 82 00:03:58.159 --> 00:04:00.960 logs for this specific plane, there is one detail that 83 00:04:01.039 --> 00:04:02.560 immediately spiked my anxiety. 84 00:04:02.639 --> 00:04:03.800 I know exactly what you're gonna say. 85 00:04:03.800 --> 00:04:06.840 The plane is perfectly legal to fly, but four days earlier, 86 00:04:07.000 --> 00:04:10.879 mechanics had completely deactivated the right engines thrust reverser. I 87 00:04:10.919 --> 00:04:12.919 want to dig into the physics of this for a second, 88 00:04:13.039 --> 00:04:16.959 because taking a mathematically handicapped plane into such an unforgiving, 89 00:04:17.040 --> 00:04:21.639 wet environment seems incredibly risky, even if it's legally permitted. 90 00:04:21.759 --> 00:04:24.439 It's a crucial detail that sets the stage for everything 91 00:04:24.439 --> 00:04:27.839 that follows. First, we need to understand the how and 92 00:04:27.879 --> 00:04:31.439 why of a thrust reverser. Okay, when a multi ton 93 00:04:31.560 --> 00:04:34.240 jet lands at one hundred and fifty miles per hour, 94 00:04:34.839 --> 00:04:37.560 the wheel brakes alone aren't always enough to stop that 95 00:04:37.680 --> 00:04:40.879 massive amount of forward momentum, especially on a short runway. 96 00:04:41.000 --> 00:04:42.839 Right, they need more stopping power. 97 00:04:42.720 --> 00:04:46.600 Exactly, so mechanisms in the engine cowlings open up to 98 00:04:46.639 --> 00:04:50.639 physically redirect the engine's exhaust thrust forward. It acts like 99 00:04:50.639 --> 00:04:54.399 a giant aerodynamic break. Makes sense now. Commercial aviation is 100 00:04:54.399 --> 00:04:58.920 built on overlapping layers of redundancy. Flying with one deactivated 101 00:04:58.959 --> 00:05:02.839 reverser is a permit routine and fundamentally safe procedure. Under 102 00:05:02.920 --> 00:05:05.920 normal conditions, you just rely on the one working reverser 103 00:05:06.240 --> 00:05:07.519 and the heavy duty wheel brakes. 104 00:05:07.560 --> 00:05:09.519 But the conditions and Sam Paula that night were the 105 00:05:09.560 --> 00:05:13.720 exact opposite of normal. Doing this on a famously short runway, 106 00:05:13.759 --> 00:05:17.879 which is currently being pounded by a winter storm, requires absolute, 107 00:05:18.040 --> 00:05:22.040 unwavering precision from the crew, and looking at the cockpit 108 00:05:22.120 --> 00:05:25.759 voice transcripts you highlighted, you can actually trace the exact 109 00:05:25.839 --> 00:05:27.839 moment the tension spikes in the cockpit. 110 00:05:27.959 --> 00:05:28.800 You really can hear it. 111 00:05:29.040 --> 00:05:31.680 While they are en route, they get word that runway 112 00:05:31.720 --> 00:05:34.480 three five L has been temporarily closed because of the 113 00:05:34.480 --> 00:05:37.959 heavy rain. They actually start planning for an alternate. 114 00:05:37.560 --> 00:05:39.920 Airport, which would have been so much safer. 115 00:05:39.600 --> 00:05:42.560 It would have. But then tragically they get an update. 116 00:05:42.800 --> 00:05:45.759 The rain has eased just enough, Runway three five L 117 00:05:45.879 --> 00:05:46.879 is active again. 118 00:05:46.680 --> 00:05:50.079 And the psychological shift there is palpable. The captain gets 119 00:05:50.120 --> 00:05:52.639 on the intercom telling the passengers the good news that 120 00:05:52.680 --> 00:05:55.279 they won't be diverted, they'll be arriving on time. 121 00:05:55.480 --> 00:05:57.600 But I'm guessing he's not feeling great about it. 122 00:05:57.720 --> 00:06:01.240 No upfront in the cockpit, that relief is entirely absent. 123 00:06:01.560 --> 00:06:05.040 They're locked into a highly stressful approach. They begin their descent, 124 00:06:05.519 --> 00:06:08.839 dropping to just three hundred feet above the sprawling glowing 125 00:06:08.879 --> 00:06:09.959 grid of sam Poulo. 126 00:06:10.480 --> 00:06:15.079 So tense, the captain calls out Land Green Manual Flight. 127 00:06:15.680 --> 00:06:19.800 He's disengaging the autopilot choosing to take manual control because 128 00:06:19.800 --> 00:06:21.879 he knows he has to bring this airbus down right 129 00:06:21.920 --> 00:06:24.000 at the very threshold of the runway. 130 00:06:24.040 --> 00:06:25.160 We heeds every inch. 131 00:06:25.160 --> 00:06:29.879 He needs to use, every single available inch of that concrete, and. 132 00:06:29.839 --> 00:06:34.040 His precision in the air is flawless. The wheels hit 133 00:06:34.079 --> 00:06:36.480 the wet tarmac exactly where they should. 134 00:06:36.600 --> 00:06:37.439 Okay, good. 135 00:06:37.600 --> 00:06:41.480 Immediately the captain deploys the single working left rust reverser, 136 00:06:41.759 --> 00:06:45.399 doing exactly what the standard operating procedure dictates for this 137 00:06:45.480 --> 00:06:47.120 specific mechanical handicap. 138 00:06:47.279 --> 00:06:49.920 But the telemetry shows the plane isn't slowing down. 139 00:06:50.040 --> 00:06:52.839 It's not slowing down at all. The cockpit recordings captured 140 00:06:52.879 --> 00:06:56.759 this immediate, terrifying realization. Oh man, you can hear the physical, 141 00:06:56.800 --> 00:06:59.920 frantic pressing of the brake pedals. They're practically standing on them, 142 00:07:00.079 --> 00:07:02.480 trying to force the hydraulic brakes to bite into the tarmac. 143 00:07:02.519 --> 00:07:03.560 And then what happens. 144 00:07:03.639 --> 00:07:07.000 And then the aircraft does something completely unexpected. It violently 145 00:07:07.079 --> 00:07:08.800 views to the left, acting as if it has a 146 00:07:08.839 --> 00:07:09.600 mind of its own. 147 00:07:09.879 --> 00:07:14.639 The massive machine Koren's entirely off the runaway. It rockets 148 00:07:14.680 --> 00:07:17.439 over the grass, over the perimeter fence, crosses a busy 149 00:07:17.519 --> 00:07:19.959 roadway right at rush hour. It's just unbelievable, and it 150 00:07:20.040 --> 00:07:24.040 slams directly into a multi story tam Airlines cargo and 151 00:07:24.079 --> 00:07:26.759 office building, as well as an adjacent gas station. 152 00:07:27.240 --> 00:07:31.600 The devastation was apocalyptic. Doctor Douglas Ferrari was one of 153 00:07:31.680 --> 00:07:33.519 the first medical responders on the scene. 154 00:07:33.560 --> 00:07:34.360 What did you see? 155 00:07:34.519 --> 00:07:37.399 Well, he arrives, hoping to set up triage and treat 156 00:07:37.439 --> 00:07:40.519 survivors from the fuselage, but the reality of the physics 157 00:07:40.519 --> 00:07:44.079 involved made that impossible because in the fire, Yeah, the 158 00:07:44.120 --> 00:07:47.079 impact ignited thousands of gallons of jet fuel from the 159 00:07:47.160 --> 00:07:50.800 ruptured wings, which then ignited the underground storage tanks of 160 00:07:50.839 --> 00:07:54.439 the gas station. It created a raging one thousand degrees 161 00:07:54.480 --> 00:07:55.519 celsius inferno. 162 00:07:55.759 --> 00:07:57.959 My god, So the fire isn't just feeding on the 163 00:07:57.959 --> 00:08:00.639 A three to twenties fuel tanks. It's a ventually tapped 164 00:08:00.680 --> 00:08:04.079 into a massive underground reservoir of combustible liquid. 165 00:08:04.319 --> 00:08:05.160 Exactly How do. 166 00:08:05.199 --> 00:08:08.360 Emergency crews even begin to establish a perimeter around that? 167 00:08:08.600 --> 00:08:10.759 The thermal radiation must have been catastrophic. 168 00:08:11.120 --> 00:08:14.199 It was so intense it was structurally melting the surrounding 169 00:08:14.240 --> 00:08:18.519 steel and concrete. Doctor Ferrari recalled seeing cars on the 170 00:08:18.519 --> 00:08:21.959 street that had instantly caught fire from their radiant heat alone, 171 00:08:22.079 --> 00:08:25.040 just from the heat, just from the heat. Despite the 172 00:08:25.120 --> 00:08:28.920 highly coordinated efforts of nearly two hundred firefighters, there was 173 00:08:28.959 --> 00:08:31.639 simply no way to penetrate that kind of thermal event 174 00:08:31.720 --> 00:08:34.879 in time. One hundred and ninety nine people perished that night, 175 00:08:35.440 --> 00:08:38.519 everyone on the plane and twelve innocent people on the ground. 176 00:08:38.639 --> 00:08:40.919 It is a staggering loss of life. And as the 177 00:08:40.919 --> 00:08:43.639 flames were finally being beaten back in the early hours 178 00:08:43.639 --> 00:08:47.519 of the morning, this desperate, frantic race for answers began. 179 00:08:47.639 --> 00:08:49.000 They needed answers immediately. 180 00:08:49.039 --> 00:08:52.039 The entire country of Brazil is looking at this smoldering 181 00:08:52.080 --> 00:08:54.559 crater in the middle of their biggest city asking one 182 00:08:54.639 --> 00:08:57.960 specific question, why didn't the plane stop. 183 00:08:58.120 --> 00:09:01.080 This is where we bring in Lieutenant Colonel Fernando Camargo, 184 00:09:01.440 --> 00:09:05.840 a lead investigator with CINEPA, that's Brazil's aviation safety agency. 185 00:09:06.480 --> 00:09:10.720 His team is operating under immense pressure. Remember another plane 186 00:09:10.720 --> 00:09:13.720 had slipped off this exact runway just a day prior. 187 00:09:14.039 --> 00:09:17.000 If they don't find the root cause immediately, they risk 188 00:09:17.279 --> 00:09:20.240 another commercial jet doing the exact same thing tomorrow. 189 00:09:20.559 --> 00:09:23.720 So, going through the CINEPA reports, he provided Camargo's first 190 00:09:23.759 --> 00:09:26.679 major breakthrough doesn't actually come from the wreckage. It comes 191 00:09:26.720 --> 00:09:28.320 from an airport security camera. 192 00:09:28.440 --> 00:09:29.360 Oh the video evidence. 193 00:09:29.559 --> 00:09:32.519 Yeah, the camera didn't capture the impact itself. It was 194 00:09:32.559 --> 00:09:34.960 pointed at a different section of the runway, but it 195 00:09:35.000 --> 00:09:38.240 caught flight three oho FE four speeding through its frame. Now, 196 00:09:38.240 --> 00:09:40.639 when investigators pull the tape of a normal A three 197 00:09:40.679 --> 00:09:43.960 to twenty landing in that exact same spot, it takes 198 00:09:44.000 --> 00:09:46.519 about nine seconds for the plane to cross from one 199 00:09:46.559 --> 00:09:47.879 side of the video frame to the other. 200 00:09:48.000 --> 00:09:49.919 Well, when they watch the tape of flight three or 201 00:09:49.919 --> 00:09:53.000 five four, it crosses the frame in just three. 202 00:09:52.759 --> 00:09:54.519 Seconds, which is insane. 203 00:09:54.600 --> 00:09:56.679 It was moving three times too fast for that stage 204 00:09:56.679 --> 00:09:57.519 of the landing. 205 00:09:57.240 --> 00:09:59.960 Which is completely baffling. So Camargo goes out to physical 206 00:10:00.039 --> 00:10:03.279 glean speck runway three five L. It's still raining, and 207 00:10:03.320 --> 00:10:08.840 what he finds is deeply concerning. There is standing water everywhere, 208 00:10:09.519 --> 00:10:12.200 large puddles are pulling on the tarmac. 209 00:10:12.320 --> 00:10:13.480 Not what you want to see. 210 00:10:13.679 --> 00:10:17.200 No. Now, this runaway had actually been entirely resurfaced just 211 00:10:17.279 --> 00:10:20.840 one month prior to the crash, specifically to fix complaints 212 00:10:20.879 --> 00:10:23.360 from pilots about slippery conditions. 213 00:10:22.960 --> 00:10:25.240 Right, and it had worked fine during the dry weeks, 214 00:10:25.480 --> 00:10:28.639 but the heavy winter rains exposed a fatal omission in 215 00:10:28.679 --> 00:10:31.919 the construction. The contractors had laid down the new asphalt, 216 00:10:32.200 --> 00:10:34.799 but they hadn't yet cut in the special safety grooves. 217 00:10:35.000 --> 00:10:36.159 Wait, what do those do? 218 00:10:36.360 --> 00:10:40.279 There are those tiny, precisely measured transverse channels that allow 219 00:10:40.399 --> 00:10:44.200 rain water to drain away. Without them, the water just 220 00:10:44.320 --> 00:10:47.320 sat in a sheer sheet on top of the tarmac. 221 00:10:47.440 --> 00:10:49.840 And here is where it gets really interesting because the 222 00:10:49.879 --> 00:10:52.399 physics of dynamic hydroplaning come into play. 223 00:10:52.480 --> 00:10:54.200 Oh yeah, hydroplanning is terrifying. 224 00:10:54.320 --> 00:10:56.759 When a jet tire hits standing water at one hundred 225 00:10:56.759 --> 00:10:59.519 and fifty miles per hour, the water simply cannot get 226 00:10:59.559 --> 00:11:02.360 out of the way fast enough. It literally forms a 227 00:11:02.360 --> 00:11:06.080 wedge under the tire, lifting it completely off the pavement. 228 00:11:05.960 --> 00:11:07.240 Like skipping a stone on a lake. 229 00:11:07.480 --> 00:11:11.480 Exactly. The tire isn't rolling on aggregate anymore. It's riding 230 00:11:11.519 --> 00:11:16.120 on an incompressible micro layer of water. The ungrooved runway 231 00:11:16.320 --> 00:11:19.919 essentially turned into a massive slip and slide, completely robbing 232 00:11:19.960 --> 00:11:22.480 the tires of their breaking frictional contact. 233 00:11:22.720 --> 00:11:24.200 It's just a terrifying scenario. 234 00:11:24.440 --> 00:11:26.720 But I have to push back here based on the data. 235 00:11:27.399 --> 00:11:31.679 Hydroplaning explains why the plane couldn't break effectively and why 236 00:11:31.679 --> 00:11:34.919 it might lose directional control, right, but it doesn't explain 237 00:11:34.960 --> 00:11:37.320 why the plane was going three times its normal speed. 238 00:11:38.240 --> 00:11:40.480 If you slide on ice in your car, you lose traction, 239 00:11:40.600 --> 00:11:43.320 but you don't suddenly accelerate. There has to be more 240 00:11:43.320 --> 00:11:44.000 to this story. 241 00:11:44.279 --> 00:11:47.159 You're exactly right to point that out. Hydroplaning was a 242 00:11:47.279 --> 00:11:51.360 major contributing factor, I mean, a terrible environmental condition that 243 00:11:51.480 --> 00:11:54.120 eliminated their safety margin, But it was not the root 244 00:11:54.240 --> 00:11:57.519 cause of that incredible speed. So what was for that? 245 00:11:58.200 --> 00:12:01.600 Investigators needed to look inside the brain of the aircraft itself, 246 00:12:02.000 --> 00:12:02.759 the black. 247 00:12:02.480 --> 00:12:06.200 Boxes, the flight data recorder, and the cockpit voice recorder. 248 00:12:06.519 --> 00:12:09.799 But getting them was a logistical nightmare. They were buried 249 00:12:09.840 --> 00:12:12.039 in the tail section, right in the heart of this 250 00:12:12.320 --> 00:12:13.759 one thousand degree inferno. 251 00:12:14.159 --> 00:12:17.519 The heat was so severe that when they finally extracted them, 252 00:12:17.799 --> 00:12:20.879 the stainless steel chassis were completely charred and warped. 253 00:12:21.120 --> 00:12:22.559 Could they even read them well? 254 00:12:22.679 --> 00:12:25.919 These devices are built to withstand immense heat, but there 255 00:12:25.960 --> 00:12:29.279 is a physical limit to the insulation inside. There are 256 00:12:29.320 --> 00:12:34.399 temperature sensitive indicator chips. When investigators at the NTSB laboratory 257 00:12:34.440 --> 00:12:37.919 in Washington opened them up. Those chips showed the memory 258 00:12:37.919 --> 00:12:41.519 boards had been exposed to temperatures far beyond their certified 259 00:12:41.559 --> 00:12:42.360 design limits. 260 00:12:42.919 --> 00:12:45.440 And the breakdown you sent us of how the NTSB 261 00:12:45.600 --> 00:12:50.240 recovered this data is fascinating. Because the internal circuitry was fried, 262 00:12:50.480 --> 00:12:53.879 the technicians actually had to bypass the damage boards entirely. 263 00:12:54.159 --> 00:12:55.320 It was incredible work. 264 00:12:55.519 --> 00:12:59.799 They carefully desoldered the raw solid state flash memory chips, 265 00:12:59.840 --> 00:13:03.919 them clean A contacts and place them onto surrogate motherboards 266 00:13:04.320 --> 00:13:06.320 just to read the raw binary code. 267 00:13:06.639 --> 00:13:08.000 Just unbelievable dedication. 268 00:13:08.159 --> 00:13:11.120 And the telemetry they pulled off those surviving Silicon ships 269 00:13:11.200 --> 00:13:13.679 absolutely completely rewrote the investigation. 270 00:13:13.840 --> 00:13:16.879 It really did. The data showed that the aircraft's touchdown 271 00:13:16.919 --> 00:13:19.960 speed was perfect, the pilot's foot brakes were fully engaged. 272 00:13:20.000 --> 00:13:24.159 They were doing everything they mechanically could. But then investigators 273 00:13:24.200 --> 00:13:27.360 look at the engine thrust data. Engine one on the 274 00:13:27.399 --> 00:13:30.320 left side was in full reverse, doing exactly what it 275 00:13:30.360 --> 00:13:32.080 was supposed to do to slow the plane down. 276 00:13:32.200 --> 00:13:34.440 But Engine two, the right engine, the one with the 277 00:13:34.519 --> 00:13:38.919 broken reverser, it wasn't just idling, it was inexplicably accelerating. 278 00:13:39.360 --> 00:13:41.240 It was set to climb power. 279 00:13:41.399 --> 00:13:45.639 Yes, it was producing a massive amount of forward thrust. 280 00:13:46.000 --> 00:13:50.039 The engines were fighting a deadly asymmetrical war against each other. 281 00:13:50.399 --> 00:13:53.000 Let's frame this asymmetrical law force so you can really 282 00:13:53.279 --> 00:13:56.360 picture the physics here. Imagine you are driving your car 283 00:13:56.440 --> 00:13:58.799 down a steep hill covered in a sheet of solid ice. 284 00:14:00.320 --> 00:14:03.000 You violently yank up the emergency brake with your left hand, 285 00:14:03.120 --> 00:14:06.000 locking the left wheels right, But at the exact same moment, 286 00:14:06.399 --> 00:14:09.000 your right foot has the gas pedal pinned completely to 287 00:14:09.039 --> 00:14:10.519 the floor, spinning the right wheels. 288 00:14:10.600 --> 00:14:11.759 It's a recipe for disaster. 289 00:14:11.879 --> 00:14:16.279 The rotational force is unimaginable. That lopsided thrust full reverse 290 00:14:16.320 --> 00:14:18.279 on the left, full forward thrust on the right is 291 00:14:18.360 --> 00:14:21.960 exactly what created a massive yawing moment, hurling the plane 292 00:14:22.080 --> 00:14:23.720 violently off the runway to the left. 293 00:14:24.000 --> 00:14:26.799 So now Colonel Camargo has to figure out why the 294 00:14:26.919 --> 00:14:31.080 right engine was accelerating. Was it a mechanical failure? Did 295 00:14:31.120 --> 00:14:32.440 the plane's computer malfunction? 296 00:14:32.559 --> 00:14:33.879 Where do they even start looking. 297 00:14:34.000 --> 00:14:36.919 They targeted a specific device called the artificial feel unit 298 00:14:37.399 --> 00:14:41.279 or AFU. This is the mechanical and electronic linkage between 299 00:14:41.279 --> 00:14:44.320 the throttle levers and the cockpit and the electronic engine 300 00:14:44.320 --> 00:14:46.360 controls the FADEC. 301 00:14:45.840 --> 00:14:49.080 System because if the AFU broke, the pilot could have 302 00:14:49.120 --> 00:14:51.799 physically pulled the lever back to the stop position, but 303 00:14:51.840 --> 00:14:53.679 the computer would still read it as being stuck in 304 00:14:53.720 --> 00:14:55.279 the forward climb position exactly. 305 00:14:55.519 --> 00:14:57.799 So they take the charred remains of this AFU from 306 00:14:57.840 --> 00:15:00.399 the wreckage and send it to a highly spec sized 307 00:15:00.440 --> 00:15:03.679 metallurgy lab. They use high tech three D scanners to 308 00:15:03.759 --> 00:15:07.440 examine the internal gears at a microscopic level, looking for damage, 309 00:15:07.480 --> 00:15:11.120 looking for any tiny scratch, any microfracture, or melted tooth 310 00:15:11.279 --> 00:15:14.720 that would indicate the unit failed, disconnected, or jammed. 311 00:15:14.840 --> 00:15:16.360 And what did the scanners find? 312 00:15:16.639 --> 00:15:20.320 Zero evidence of malfunction. The three D scans proved the 313 00:15:20.360 --> 00:15:23.919 internal gears were perfectly aligned at the moment of impact. Wow, 314 00:15:24.000 --> 00:15:26.360 the machine was flawless. It did exactly what it was 315 00:15:26.399 --> 00:15:28.639 physically told to do, which means. 316 00:15:28.679 --> 00:15:31.080 If the machine didn't fail, we are left with a 317 00:15:31.200 --> 00:15:35.080 chilling reality. The error came from the humans sitting in 318 00:15:35.080 --> 00:15:35.679 the cockpit. 319 00:15:36.080 --> 00:15:37.240 It's the only explanation. 320 00:15:37.399 --> 00:15:40.279 The telemetry and the mechanical evidence proved that the pilots 321 00:15:40.320 --> 00:15:44.320 themselves left the right throttle lever pushed forward into climb power. 322 00:15:44.799 --> 00:15:48.799 But how How could two veteran pilots with nearly thirty 323 00:15:48.840 --> 00:15:52.360 thousand hours of combined flight experience make such a basic 324 00:15:52.720 --> 00:15:55.960 fatal mistake during the most critical moment of the flight. 325 00:15:56.399 --> 00:15:59.840 To answer that, the investigation shift entirely from engineering to 326 00:16:00.080 --> 00:16:04.480 human psychology. Camargo brings in a human Factors team led 327 00:16:04.519 --> 00:16:07.879 by a Lieutenant Colonel Marcia Faria and First Lieutenant Vanessa 328 00:16:07.960 --> 00:16:12.080 dyas Okay. Their job is to perform a psychological autopsy 329 00:16:12.120 --> 00:16:15.080 of the crew. They start by meticulously listening to the 330 00:16:15.080 --> 00:16:18.519 copyit voice recorder, analyzing not just the words the pilot said, 331 00:16:18.679 --> 00:16:21.159 but the tone of their voices, their breathing patterns, and 332 00:16:21.200 --> 00:16:22.320 the speed of their speech. 333 00:16:22.399 --> 00:16:25.919 And they discovered that Captain Steffanini's physiological state was deeply 334 00:16:26.000 --> 00:16:29.159 compromised by stress, very much so before they even saw 335 00:16:29.159 --> 00:16:31.919 the runway. You hear air traffic control radio in and 336 00:16:31.960 --> 00:16:36.080 report the runway conditions as wet and slippery. The psychological 337 00:16:36.080 --> 00:16:39.879 analysis notes this is the exact moment his sympathetic nervous 338 00:16:39.879 --> 00:16:41.320 system kicks into overdrive. 339 00:16:41.559 --> 00:16:42.639 You can hear the change. 340 00:16:42.799 --> 00:16:46.759 The captain starts asking repetitive questions, His breathing becomes shallow 341 00:16:46.759 --> 00:16:50.879 and rapid. He is experiencing high cognitive anxiety. 342 00:16:50.360 --> 00:16:53.600 And reasonably so. He's approaching the aircraft carrier with a 343 00:16:53.639 --> 00:16:58.080 handicapped plane. But this is where the mystery deepens. The 344 00:16:58.159 --> 00:17:00.879 investigators look at the flight data from just a few 345 00:17:00.919 --> 00:17:03.440 hours earlier, on that exact same day. 346 00:17:03.559 --> 00:17:06.799 Yes, this is the baffling contradiction in the flight logs 347 00:17:06.799 --> 00:17:10.039 you provided that completely threw me. Just hours before this 348 00:17:10.079 --> 00:17:13.880 fatal crash, Captain Stefani landed this exact same plane with 349 00:17:14.000 --> 00:17:19.000 the exact same broken right reverser flawlessly in Porto Alegre. 350 00:17:18.759 --> 00:17:20.079 A completely perfect landing. 351 00:17:20.160 --> 00:17:22.559 It was a perfect landing at two pm. He used 352 00:17:22.559 --> 00:17:26.519 the standard modern airbus procedure. You pull both throttle levers 353 00:17:26.559 --> 00:17:28.319 all the way back to idle, and then you pull 354 00:17:28.400 --> 00:17:31.640 the one working lever further back into reverse. The onboard 355 00:17:31.640 --> 00:17:35.319 computer handles the rest, keeping the broken engines safely at idle. 356 00:17:35.559 --> 00:17:38.680 He did it perfectly, So why at five five pm 357 00:17:38.720 --> 00:17:41.200 and San Polo did he leave the right engine lever 358 00:17:41.319 --> 00:17:42.599 pushed all the way forward. 359 00:17:42.880 --> 00:17:45.440 What's fascinating here is the history of how pilots were 360 00:17:45.480 --> 00:17:49.799 trained to handle this specific malfunction and the aerodynamics behind it. 361 00:17:50.279 --> 00:17:54.039 The investigators discovered that there was an older, outdated procedure 362 00:17:54.079 --> 00:17:56.039 for landing with a broken. 363 00:17:55.680 --> 00:17:57.640 Reverser an older procedure. 364 00:17:57.799 --> 00:18:00.960 Yeah, years prior, pilots were taught to leave the broken 365 00:18:01.000 --> 00:18:04.599 engine's throttle lever alone, like leave it in its forward 366 00:18:04.599 --> 00:18:07.319 thrust position and only pull back the working lever. 367 00:18:07.559 --> 00:18:10.559 But wait, why would Airbus ever teach pilots to leave 368 00:18:10.599 --> 00:18:13.000 an engine pushing forward during a landing. 369 00:18:12.960 --> 00:18:16.319 Because of the aerodynamics of the older engine designs. In 370 00:18:16.359 --> 00:18:20.000 those older models, keeping that broken engine spooled up actually 371 00:18:20.119 --> 00:18:22.680 kept airflow moving over the wing flaps in a very 372 00:18:22.680 --> 00:18:26.559 specific way that increased aerodynamic drag. Oh I see this 373 00:18:26.680 --> 00:18:29.960 downward pressure helped push the wheels harder into the tarmac, 374 00:18:30.000 --> 00:18:34.000 giving the tires better braking traction. It mathematically shaved precious 375 00:18:34.039 --> 00:18:35.319 meters off the landing distance. 376 00:18:35.319 --> 00:18:37.200 But that sounds incredibly risky it was. 377 00:18:38.000 --> 00:18:42.000 Airbus eventually realized it was a terrible, highly dangerous procedure. 378 00:18:42.880 --> 00:18:46.799 Under stress, pilots were accidentally leaving that broken engine lever 379 00:18:46.920 --> 00:18:50.920 too far forward, generating massive forward thrust instead of just 380 00:18:51.000 --> 00:18:51.559 leaving it in. 381 00:18:51.480 --> 00:18:53.640 A high idol like what happened here exactly. 382 00:18:53.640 --> 00:18:57.960 They had previous non fatal accidents where this exact confusion happened, 383 00:18:58.480 --> 00:19:02.480 So Airbus completely banned the old procedure and issued a new, safer, 384 00:19:02.480 --> 00:19:05.000 simplified one, pulled both levers back. 385 00:19:05.079 --> 00:19:09.200 The exact procedure Stefani used flawlessly in Quardolegre exactly. 386 00:19:09.480 --> 00:19:12.880 But Captain Stefaniti, being a veteran who had flown for decades, 387 00:19:13.200 --> 00:19:15.359 had been trained on both the old procedure and the 388 00:19:15.400 --> 00:19:19.359 new one during his long career. Both motor pathways existed 389 00:19:19.359 --> 00:19:19.920 in his brain. 390 00:19:20.079 --> 00:19:22.920 Okay, So to put this all together, Lieutenant Das goes 391 00:19:22.960 --> 00:19:25.759 into a state of the art flight simulator, the program 392 00:19:25.839 --> 00:19:28.880 in the exact weather, the exact plane weight, the exact 393 00:19:28.880 --> 00:19:32.000 wet runway, the broken reverser, and she starts flying the 394 00:19:32.039 --> 00:19:34.119 approach over and over, trying to get into the mind 395 00:19:34.119 --> 00:19:37.079 of the captain, trying to induce the same cognitive loud 396 00:19:37.240 --> 00:19:37.559 and in. 397 00:19:37.519 --> 00:19:41.640 The simulator the psychological pieces finally lock into place. Imagine you, 398 00:19:41.720 --> 00:19:45.559 or Captain Stefani, you are terrified of runway three five LS. 399 00:19:46.200 --> 00:19:48.759 You know it's wet, you know it's ungrooved, you know 400 00:19:48.839 --> 00:19:51.920 a plane slid off it yesterday. Yeah, you're amigdala is 401 00:19:52.000 --> 00:19:55.680