WEBVTT 1 00:00:00.160 --> 00:00:05.280 So picture a really warm, late summer morning over the 2 00:00:05.360 --> 00:00:08.320 sprawling farms and cattle ranches of southern Texas. 3 00:00:08.400 --> 00:00:11.279 Well, yeah, just one of those perfectly clear days exactly. 4 00:00:11.400 --> 00:00:15.519 The sky is just this endless, pristine blue, and up 5 00:00:15.560 --> 00:00:18.640 at about fifteen thousand feet you've got Continental Express flight 6 00:00:18.719 --> 00:00:21.559 twenty five seven four. It's beginning what you know, should 7 00:00:21.600 --> 00:00:24.600 be a completely routine descent into Houston, right. 8 00:00:24.480 --> 00:00:26.879 And it's an Embryer one twenty, which is a twin 9 00:00:26.920 --> 00:00:27.920 turboprop plane. 10 00:00:28.000 --> 00:00:31.359 Yeah. And inside the cockpit, the atmosphere is just incredibly relaxed. 11 00:00:31.719 --> 00:00:34.359 You have twenty nine year old Captain Brad Patridge and 12 00:00:34.640 --> 00:00:39.119 forty three year old First Officer Clint Rossovich. They're laughing, 13 00:00:39.159 --> 00:00:41.600 they're talking about their upcoming days off, making plans to 14 00:00:41.600 --> 00:00:43.039 play a little golf down on the coast. 15 00:00:43.280 --> 00:00:45.399 It's just, by all accounts, of perfectly normal day, just 16 00:00:45.439 --> 00:00:49.240 another morning commuter flight, really right, and crucially, I mean 17 00:00:49.320 --> 00:00:51.280 it was actually their second flight of the day in 18 00:00:51.320 --> 00:00:54.280 that very same aircraft. They had already flown from Houston 19 00:00:54.320 --> 00:00:57.799 down to Laredo entirely without a hitch. Now they were 20 00:00:57.840 --> 00:00:59.159 just making their return trip home. 21 00:00:59.359 --> 00:01:01.479 But then on the ground you have these two brothers, 22 00:01:01.560 --> 00:01:03.719 Carrie and Clifton, and they're just working on their tattle 23 00:01:03.719 --> 00:01:06.879 farm and the quiet of that morning is suddenly just 24 00:01:07.560 --> 00:01:09.760 shattered by a massive explosion up in the sky. 25 00:01:09.959 --> 00:01:10.239 Wow. 26 00:01:10.439 --> 00:01:13.519 Yeah. They look up and what they see is terrifying, 27 00:01:13.920 --> 00:01:17.480 and aircraft is spiraling downward, completely out of control. It 28 00:01:17.560 --> 00:01:20.040 plummets two thousand feet in mere seconds. 29 00:01:20.120 --> 00:01:21.560 That's incredibly fast it is. 30 00:01:21.640 --> 00:01:24.319 It slams into the earth at over five hundred kilometers 31 00:01:24.319 --> 00:01:28.920 per hour, which sends this secondary earth shaking explosion echoing 32 00:01:28.959 --> 00:01:30.280 across the Texas planes. 33 00:01:30.680 --> 00:01:33.480 The sheer speed and while the violence of it left 34 00:01:33.519 --> 00:01:36.000 observers on the ground in absolute shock. 35 00:01:35.840 --> 00:01:38.840 Which brings us to our topic. Welcome to today's deep dive. 36 00:01:39.120 --> 00:01:42.000 We have gathered a really fascinating stack of sources for 37 00:01:42.079 --> 00:01:47.599 this one, declassified NTSB accident reports, aviation engineering blueprints, historical 38 00:01:47.640 --> 00:01:49.879 flight data, original investigative notes. 39 00:01:49.920 --> 00:01:52.280 It's a lot of material and our mission today is 40 00:01:52.319 --> 00:01:54.840 to step directly into the shoes of the real life 41 00:01:54.920 --> 00:01:59.799 aviation accident investigators who are tasked with solving this mystery. 42 00:02:00.000 --> 00:02:04.719 Going to meticulously piece together how a perfectly functioning modern 43 00:02:04.799 --> 00:02:08.120 aircraft was doomed not by a violent storm and not 44 00:02:08.199 --> 00:02:11.639 by a bomb, but by a chain of seemingly microscopic, 45 00:02:11.759 --> 00:02:16.520 well intentioned human errors, errors that culminated in a catastrophic 46 00:02:16.599 --> 00:02:17.879 inflight breakup. 47 00:02:17.560 --> 00:02:19.800 Right, because the story really is a masterclass in how 48 00:02:19.840 --> 00:02:21.000 complex systems fail. 49 00:02:21.199 --> 00:02:24.080 It really is. It proves that for you, in literally 50 00:02:24.120 --> 00:02:28.639 any job, skipping what feels like a routine, tedious, administrative 51 00:02:28.639 --> 00:02:31.199 step can have unimaginable consequences. 52 00:02:31.319 --> 00:02:35.000 Absolutely, and setting the scene on the ground near Eagle Lake, Texas, 53 00:02:35.000 --> 00:02:37.599 which is about one hundred and ten kilometers west of Houston, 54 00:02:38.120 --> 00:02:40.759 he was just absolute devastation. I can only imagine, Yeah, 55 00:02:40.759 --> 00:02:43.400 when the NTSB GO team arise at a crash site, 56 00:02:43.520 --> 00:02:46.360 I mean they're trained to process trauma, but this scene 57 00:02:46.439 --> 00:02:49.680 was particularly daunting. The smell of jet fuel and charred 58 00:02:49.680 --> 00:02:51.080 earth hung really. 59 00:02:50.879 --> 00:02:53.000 Heavy in the air, right, and the impact was so 60 00:02:53.120 --> 00:02:55.960 violent that the aircraft was completely pulverized into the soil. 61 00:02:56.000 --> 00:02:58.199 Like I was reading the one local observer set, if 62 00:02:58.240 --> 00:02:59.520 you didn't know what was an airplane, you would have 63 00:02:59.520 --> 00:03:01.319 just thought it was a pile of pop trash. 64 00:03:01.560 --> 00:03:05.080 It's just horrifying. All fourteen souls on board, so that's 65 00:03:05.120 --> 00:03:09.439 twelve passengers and the two pilots were gone. The investigators 66 00:03:09.439 --> 00:03:13.599 are walking into this chaotic, heartbreaking scene and they need 67 00:03:13.680 --> 00:03:14.599 answers immediately. 68 00:03:14.680 --> 00:03:17.800 Right away, a leading theory emerges, and honestly, if I'm 69 00:03:17.840 --> 00:03:20.159 listening to this and looking at the initial facts, I'm 70 00:03:20.199 --> 00:03:23.080 thinking it has to be a bomb. Oh, totally right, 71 00:03:23.159 --> 00:03:26.680 because you have eyewitnesses who are unanimous. They all swore 72 00:03:26.800 --> 00:03:29.080 they saw an explosion in mid air. One of them 73 00:03:29.080 --> 00:03:31.080 even said it looked like a hole the size of 74 00:03:31.120 --> 00:03:33.800 a Volkswagen was blown right into the side of the plane. 75 00:03:33.879 --> 00:03:36.080 And you know, the radar data seemed to support that 76 00:03:36.159 --> 00:03:39.400 initial hypothesis too. Oh really, Yeah, When air traffic controllers 77 00:03:39.439 --> 00:03:42.240 review the FAA radar tapes, they saw the plane drop 78 00:03:42.280 --> 00:03:45.639 off the screen instantly, which is unusual, very Usually, a 79 00:03:45.680 --> 00:03:48.240 struggling plane will leave a descending trail of radar hits. 80 00:03:48.840 --> 00:03:52.479 Disappearing instantly is the hallmark of an aircraft just disintegrating 81 00:03:52.479 --> 00:03:52.919 in the sky. 82 00:03:53.120 --> 00:03:55.439 And to make the bomb theory feel like a total 83 00:03:55.439 --> 00:03:59.719 slam dunk, the FBI receives this emergency tip. A federally 84 00:04:00.000 --> 00:04:03.800 detected witness in a major drug trial was supposedly booked 85 00:04:03.800 --> 00:04:04.919 on this exact flight. 86 00:04:05.360 --> 00:04:07.319 I mean, you can't write that, no. 87 00:04:07.840 --> 00:04:11.360 You have fire in the sky, instant radar disappearance, and 88 00:04:11.400 --> 00:04:14.639 this clear cinematic motive for foul play. 89 00:04:14.800 --> 00:04:18.600 So the FBI naturally swarmed the wreckage. They began meticulously 90 00:04:18.720 --> 00:04:22.120 swabbing the twisted metal, sending samples to their labs to 91 00:04:22.160 --> 00:04:25.680 test for chemical residue you know, nitrates, PTN, anything that 92 00:04:25.720 --> 00:04:28.839 would indicate high explosives. But the results, the lab results 93 00:04:28.879 --> 00:04:33.199 came back completely clean, zero chemical residue. There was absolutely 94 00:04:33.199 --> 00:04:34.879 no forensic evidence of a bomb. 95 00:04:35.079 --> 00:04:38.240 Okay, so the investigation has to pivot hard because if 96 00:04:38.279 --> 00:04:40.480 there was no bomb, how does a commercial plane just 97 00:04:40.639 --> 00:04:42.279 fall out of the sky in pieces? Right? 98 00:04:42.360 --> 00:04:45.360 And this is where structural experts like the NTSBS depack 99 00:04:45.439 --> 00:04:49.199 Joshi takeover. Joshi's first order of business at any crash 100 00:04:49.240 --> 00:04:51.399 site is to locate the four corners of. 101 00:04:51.319 --> 00:04:54.199 The airplane the nose, the tail, and the two wing tips. 102 00:04:54.000 --> 00:04:56.000 Exactly, and the embry are one twenty is what we 103 00:04:56.040 --> 00:04:58.879 call a ttail aircraft. So if you picture a commercial airplane, 104 00:04:59.279 --> 00:05:01.360 instead of the horror horizontal wings on the tail being 105 00:05:01.399 --> 00:05:03.800 down at the bottom near the fuselage, they sit all 106 00:05:03.839 --> 00:05:04.759 the way up on top of. 107 00:05:04.759 --> 00:05:07.560 The vertical fin so it looks like a giant capital. 108 00:05:07.240 --> 00:05:11.959 T precisely, but Joji can't find that horizontal stabilizer in 109 00:05:12.000 --> 00:05:15.079 the main crater. He eventually locates it a full two 110 00:05:15.199 --> 00:05:18.399 hundred meters away from the rest of the pulverized wreckage. Wow. 111 00:05:18.560 --> 00:05:19.839 Two hundred meters. 112 00:05:19.560 --> 00:05:22.399 Yeah, and finding heavy components scattered that far away from 113 00:05:22.399 --> 00:05:25.839 the main impact zone, Well, it confirms the eyewitness reports. 114 00:05:26.319 --> 00:05:28.600 The plane did break apart while it was still high 115 00:05:28.639 --> 00:05:29.040 in the air. 116 00:05:29.160 --> 00:05:31.560 Okay, let me ask a question here. If it wasn't 117 00:05:31.600 --> 00:05:33.439 a bomb, how does a tail just snap off a 118 00:05:33.439 --> 00:05:36.120 plane in midair? My first thought goes to the age 119 00:05:36.160 --> 00:05:38.639 of the aircraft. Could it be metal fatigue? 120 00:05:38.879 --> 00:05:40.519 Like taking a paper clip and bending. 121 00:05:40.319 --> 00:05:43.040 It back and forth exactly until the metal finally just 122 00:05:43.199 --> 00:05:43.800 gives out. 123 00:05:44.000 --> 00:05:46.720 It's a good thought, and investigators can actually read broken 124 00:05:46.759 --> 00:05:50.319 metal like a book to answer that exact question. When 125 00:05:50.319 --> 00:05:53.319 a piece of aircraft illuminum fails from fatigue, it's a 126 00:05:53.319 --> 00:05:56.360 slow process, right. The metal bends back and forth over 127 00:05:56.439 --> 00:05:59.839 thousands of flights, and as the crack grows, the edges 128 00:06:00.040 --> 00:06:02.839 up against each other, smoothing the metal out. By the 129 00:06:02.839 --> 00:06:06.480 time it finally snaps, the brake is often smooth, clean 130 00:06:06.800 --> 00:06:09.839 and shows clear signs of dark oxidation or rust where 131 00:06:09.879 --> 00:06:11.600 air has been seeping in over time. 132 00:06:11.879 --> 00:06:15.319 So they put the embreyer's tail under a microscope. What 133 00:06:15.439 --> 00:06:16.920 did the fracture surfaces look like? 134 00:06:17.160 --> 00:06:21.120 They were jagged, bright, and violently torn. There were no 135 00:06:21.279 --> 00:06:25.000 smooth striations, no rust, and no signs of long term 136 00:06:25.000 --> 00:06:25.560 wear and tear. 137 00:06:25.680 --> 00:06:27.920 It's not metal fatigue, not at all. 138 00:06:28.079 --> 00:06:31.519 This is known as ductile overload. It told the investigators 139 00:06:31.759 --> 00:06:34.240 that the tail was ripped off suddenly by a massive, 140 00:06:34.639 --> 00:06:39.160 instantaneous aerodynamic force. It's a perfectly healthy piece of metal 141 00:06:39.360 --> 00:06:41.480 that was violently snapped by a force that was never 142 00:06:41.480 --> 00:06:42.279 designed to handle. 143 00:06:42.680 --> 00:06:46.519 Man. So, if the tail was ripped off by aerodynamic force, 144 00:06:46.920 --> 00:06:50.360 something else must have triggered the instability, right, because airplanes 145 00:06:50.360 --> 00:06:53.480 are designed to handle immense pressure, something had to disrupt 146 00:06:53.480 --> 00:06:54.560 the airflow exactly. 147 00:06:54.839 --> 00:06:57.439 To figure this out, investigators had to find the very 148 00:06:57.480 --> 00:07:00.519 first piece that fell off the plane, the ocean. His 149 00:07:00.560 --> 00:07:03.079 team examined the severed tail section resting in the field. 150 00:07:03.399 --> 00:07:06.480 They noticed a critical component was missing entirely. What was 151 00:07:06.519 --> 00:07:09.319 it the left leading edge of the horizontal stabilizer. 152 00:07:09.519 --> 00:07:11.879 Okay, so for those of you trying to picture this, 153 00:07:12.319 --> 00:07:16.040 the leading edge is a ten foot or roughly three 154 00:07:16.079 --> 00:07:20.279 meter piece of molded composite material. It sits on the 155 00:07:20.399 --> 00:07:22.639 very front lip of the tailwing. 156 00:07:22.560 --> 00:07:25.160 Right, and its job is to cleanly slice through the 157 00:07:25.199 --> 00:07:28.639 air and direct the airflow smoothly over the surface of 158 00:07:28.680 --> 00:07:32.759 the tail. It is absolutely critical for the plane's aerodynamic. 159 00:07:32.319 --> 00:07:34.720 And because it was missing from the tail assembly, it 160 00:07:34.839 --> 00:07:40.279 kicked off this exhausting massive search operation. Finding a grayish 161 00:07:40.319 --> 00:07:45.120 composite piece in the rough, grayish brown Texas scrubland is 162 00:07:45.160 --> 00:07:46.079 incredibly difficult. 163 00:07:46.120 --> 00:07:47.800 Well, it's like finding a needle in a haystack. 164 00:07:48.000 --> 00:07:51.600 Totally. They mapped out a twelve square kilometer grid. They 165 00:07:51.600 --> 00:07:55.759 had teams on four wheelers and helicopters flying overhead scouring 166 00:07:55.759 --> 00:07:58.920 the landscape and the oppressive Texas heat for three full days. 167 00:07:59.120 --> 00:08:02.199 They even brought in engineers from the aircraft manufacturer. They 168 00:08:02.279 --> 00:08:05.920 calculated the exact weight and aerodynamic drag of that specific 169 00:08:05.920 --> 00:08:06.879 ten foot piece. 170 00:08:06.759 --> 00:08:08.759 Right, and then they cross referenced it with the radar 171 00:08:08.800 --> 00:08:11.160 timestams and the wind vectors from that morning, just to 172 00:08:11.199 --> 00:08:14.120 calculate the mathematical trajectory of where it might have drifted there. 173 00:08:14.160 --> 00:08:16.600 Finally, on the third day, a searcher in a helicopter 174 00:08:16.639 --> 00:08:17.120 spots it. 175 00:08:17.519 --> 00:08:18.639 Where was it? 176 00:08:18.639 --> 00:08:21.759 It was resting against a cattle fence over a kilometer 177 00:08:21.800 --> 00:08:25.680 away from the tail section. It was perfectly camouflaged against 178 00:08:25.720 --> 00:08:29.199 the wire and the dirt. Ground teams had likely walked 179 00:08:29.279 --> 00:08:30.839 right past it multiple times. 180 00:08:31.399 --> 00:08:34.440 But when investigators finally get their hands on it, they 181 00:08:34.480 --> 00:08:38.320 make a chilling discovery. They look closely at the screw holes, 182 00:08:38.360 --> 00:08:40.840 the mounting points where this piece attaches to the rest 183 00:08:40.879 --> 00:08:41.679 of the tail. 184 00:08:41.519 --> 00:08:42.320 And what do they find. 185 00:08:42.840 --> 00:08:44.879 The screw holes on the bottom of the piece are 186 00:08:45.039 --> 00:08:49.399 heavily elongated. They're violently cracked and torn, which proves they 187 00:08:49.399 --> 00:08:52.240 had been forcefully ripped right through the metal fasteners during 188 00:08:52.279 --> 00:08:54.840 the breakup. Right But the screw holes on the top 189 00:08:54.919 --> 00:08:56.000 of the piece, they. 190 00:08:55.840 --> 00:09:01.639 Were pristine, absolutely perfect, no elongation, no tearing, no stress 191 00:09:01.679 --> 00:09:02.600 marks of any kind. 192 00:09:02.720 --> 00:09:04.720 Wait, if the top holes are perfect, that means there 193 00:09:04.759 --> 00:09:07.960 was no force rooping them out. The screws weren't torn out, 194 00:09:08.080 --> 00:09:09.679 they just simply weren't there to begin with. 195 00:09:10.000 --> 00:09:14.200 The forensic evidence was undeniable. There were absolutely no screws 196 00:09:14.240 --> 00:09:16.360 holding the top of that leading edge to the tail. 197 00:09:16.799 --> 00:09:19.600 It was essentially flapping in the wind, held onto the 198 00:09:19.639 --> 00:09:21.559 airplane only by the screws on the bottom. 199 00:09:21.919 --> 00:09:26.039 Okay, knowing those top screws were missing is an incredible breakthrough, 200 00:09:26.679 --> 00:09:29.320 but it creates a whole new mystery. We have a 201 00:09:29.360 --> 00:09:33.519 plane flying without its screws. To understand how that translates 202 00:09:33.559 --> 00:09:36.240 into a sudden, violent crash, we need to know what 203 00:09:36.279 --> 00:09:37.360 was happening in the cockpit. 204 00:09:37.600 --> 00:09:39.480 We need the black boxes exactly. 205 00:09:39.799 --> 00:09:42.320 So, the cockpit voice recorder, the CVR and the flight 206 00:09:42.399 --> 00:09:45.960 data recorder the FDR were recovered and rushed to the 207 00:09:46.080 --> 00:09:47.919 NTSB lab in Washington. 208 00:09:48.360 --> 00:09:51.120 And when you recover a CVR from an inflight breakup, 209 00:09:51.440 --> 00:09:54.360 you brace yourself. You expect to hear the chaotic sounds 210 00:09:54.360 --> 00:09:58.519 of an emergency blaring, master alarms, engine screaming, pilots frantically 211 00:09:58.519 --> 00:09:59.879 shouting and trying to muscle the flight. 212 00:10:00.679 --> 00:10:03.080 But the investigators put their headphones on and they hear 213 00:10:03.200 --> 00:10:03.720 none of that. 214 00:10:04.000 --> 00:10:04.240 Nothing. 215 00:10:05.000 --> 00:10:07.799 The audio is crystal clear and it is entirely routine. 216 00:10:07.840 --> 00:10:10.639 The pilots are calm. First Officer Roseovic even makes a 217 00:10:10.720 --> 00:10:13.440 joke as he begins their descent into Houston. He says, 218 00:10:13.600 --> 00:10:15.879 pushing this descent making like the Space Shuttle. 219 00:10:16.080 --> 00:10:16.399 Wow. 220 00:10:16.559 --> 00:10:20.080 And then nothing new, warning, alarms, no shouts, just the abrupt, 221 00:10:20.159 --> 00:10:21.480 violent end of the recording. 222 00:10:21.759 --> 00:10:24.360 Yeah, because the speed of the breakup was beyond human 223 00:10:24.440 --> 00:10:28.279 reaction time. The sudden loss of the tail threw the 224 00:10:28.360 --> 00:10:32.080 plane into what we call a massive negative G force maneuver. 225 00:10:32.679 --> 00:10:35.320 What does that actually mean for the human body? Like, 226 00:10:35.360 --> 00:10:38.080 what do negative five g's do to a person in 227 00:10:38.120 --> 00:10:39.240 a fraction of a second. 228 00:10:39.759 --> 00:10:42.039 Well, when you ride a roller coaster and get pushed 229 00:10:42.039 --> 00:10:45.840 down into your seat, those are positive G forces. Blood 230 00:10:45.879 --> 00:10:49.679 drains from your head. Negative G forces do the exact opposite. 231 00:10:49.799 --> 00:10:52.960 You are violently thrown upward against your seatbelt, oh man, 232 00:10:53.080 --> 00:10:55.559 and negative five g's all the blood in your body 233 00:10:55.840 --> 00:10:59.440 rushes instantly into your brain. It causes a phenomenon called 234 00:10:59.440 --> 00:11:02.559 a red out, followed by immediate unconsciousness. 235 00:11:02.559 --> 00:11:03.360 So they didn't even know. 236 00:11:03.679 --> 00:11:07.559 No, the pilots and passengers were completely incapacitated before they 237 00:11:07.559 --> 00:11:10.039 even had time to register that something was wrong. 238 00:11:10.120 --> 00:11:13.320 Which I guess is a small mercy in a horrific situation. 239 00:11:14.080 --> 00:11:16.480 But I keep coming back to a glaring contradiction in 240 00:11:16.519 --> 00:11:19.080 the timeline here. This was the crew's second flight of 241 00:11:19.120 --> 00:11:22.000 the day in this exact plane. They had already flown 242 00:11:22.039 --> 00:11:25.399 over eight hundred kilometers from Houston down to Laredo that morning, 243 00:11:25.720 --> 00:11:29.679 presumably with those exact same screws missing, and they landed safely. 244 00:11:30.759 --> 00:11:33.000 Why did the plane decide to fall apart? Now on 245 00:11:33.039 --> 00:11:34.600 the way back, the flight. 246 00:11:34.440 --> 00:11:37.519 Data recorder solves that puzzle, and it all comes down 247 00:11:37.559 --> 00:11:40.639 to aero dynamic pressure. On their first flight of the 248 00:11:40.679 --> 00:11:43.639 day down to Laredo, the flight data shows the plane's 249 00:11:43.639 --> 00:11:46.919 maximum speed was two hundred and sixteen knots, which is 250 00:11:46.919 --> 00:11:49.879 about two hundred and fifty miles per hour. Okay, the 251 00:11:49.919 --> 00:11:53.440 aerodynamic forces pushing against that loose leading edge were strong, 252 00:11:53.799 --> 00:11:55.159 but the bottom screws held on. 253 00:11:55.639 --> 00:11:57.840 But on the fatal return trip they went faster. 254 00:11:58.159 --> 00:12:01.039 Remember First Officer Roseovich saying that or making like this 255 00:12:01.159 --> 00:12:05.320 space shuttle, He initiated a steep, rapid descent into Houston. 256 00:12:05.840 --> 00:12:08.720 The FDR data graph shows the plane speed surging to 257 00:12:08.799 --> 00:12:11.519 two hundred and sixty knots, that is almost three hundred 258 00:12:11.519 --> 00:12:12.159 miles per hour. 259 00:12:12.480 --> 00:12:15.000 Let's put this an everyday perspective for you guys. Imagine 260 00:12:15.039 --> 00:12:17.240 you're driving your car and your hood latch is broken, 261 00:12:17.279 --> 00:12:19.639 but you don't realize it. If you're just driving around 262 00:12:19.679 --> 00:12:22.159 your neighborhood at thirty miles an hour, the weight of 263 00:12:22.200 --> 00:12:24.919 the hood keeps it down. The wind isn't strong enough 264 00:12:24.919 --> 00:12:27.240 to lift it. But the second you merge onto the 265 00:12:27.320 --> 00:12:30.679 highway and hit eighty miles an hour, that increased wind 266 00:12:30.720 --> 00:12:33.919 resistance gets under the front lip of the hood, catches 267 00:12:33.960 --> 00:12:36.720 it like a parasuit, and violently rips it open. 268 00:12:37.000 --> 00:12:40.480 That mechanism is exactly what happened at fifteen thousand feet 269 00:12:41.080 --> 00:12:44.960 at three hundred miles per hour. The intense aerodynamic drag 270 00:12:45.200 --> 00:12:48.799 finally caught the unattached top lip of that leading edge. 271 00:12:49.240 --> 00:12:52.200 The wind literally got inside the structure of the tailwing 272 00:12:52.279 --> 00:12:54.240 and it just bent it back. It bent the composite 273 00:12:54.279 --> 00:12:57.519 material downward further and further until the sheer force of 274 00:12:57.559 --> 00:13:00.000 the oncoming air snapped the piece completely off. 275 00:13:00.159 --> 00:13:02.320 Okay, I understand how the piece fell off, But earlier 276 00:13:02.360 --> 00:13:04.759 you said the main wings ripped off the fuselage. Wait, 277 00:13:05.360 --> 00:13:07.600 the tail piece falls off, but the main wings rip off. 278 00:13:07.759 --> 00:13:08.480 How does that work? 279 00:13:08.639 --> 00:13:11.799 Yeah, So to understand the catastrophic chain reaction, you need 280 00:13:11.840 --> 00:13:15.559 to know how a horizontal stabilizer functions. It operates essentially 281 00:13:15.600 --> 00:13:18.159 like an upside down wing. While the main wings of 282 00:13:18.159 --> 00:13:20.960 an airplane create lift to pull the plane up, the 283 00:13:21.000 --> 00:13:25.159 horizontal statilizer creates downward aerodynamic pressure to push the tail down. 284 00:13:25.879 --> 00:13:29.039 This acts as a counterbalance against the heavy engines and fuselage, 285 00:13:29.480 --> 00:13:31.240 keeping the nose of the plane up and level. 286 00:13:31.440 --> 00:13:33.720 So when that leading edge stepped. 287 00:13:33.320 --> 00:13:36.639 Off, it instantly destroyed that downward pressure on the tail. 288 00:13:37.360 --> 00:13:41.759 Without that aerodynamic counterbalance pushing down, the tail violently popped 289 00:13:41.799 --> 00:13:44.559 up into the air. This forced the heavy nose of 290 00:13:44.600 --> 00:13:48.320 the plane down into that unrecoverable negative five g dies. 291 00:13:48.440 --> 00:13:51.279 Oh wow, And now to your question about the wings. 292 00:13:51.919 --> 00:13:56.039 Commercial airframes are incredibly strong, but they're designed to handle 293 00:13:56.240 --> 00:13:59.480 upward lift positive gs. They are meant to be supported 294 00:13:59.480 --> 00:14:03.000 by the air underneath them. Right when the nose violently 295 00:14:03.039 --> 00:14:07.000 pitched down, the entire aircraft was subjected to extreme downward 296 00:14:07.039 --> 00:14:10.559 structural stress. It was never engineered to handle. The main 297 00:14:10.639 --> 00:14:14.080 wing spars simply snapped upward as the fuselage was thrown 298 00:14:14.159 --> 00:14:17.679 violently down. The plane literally disassembled itself in the sky. 299 00:14:18.159 --> 00:14:21.480 So the physics explained the crash perfectly. A steep descent 300 00:14:21.639 --> 00:14:25.039 created extreme drag, which caught a loose piece of composite, 301 00:14:25.080 --> 00:14:27.960 which destroyed the counterbalance, which forced the plane into a 302 00:14:28.080 --> 00:14:31.440 dive that tore the airframe apart exactly but airplane parts 303 00:14:31.480 --> 00:14:34.679 don't just unscrew themselves. To find the true culprit, we 304 00:14:34.759 --> 00:14:36.840 have to figure out who touched that tail last. 305 00:14:37.240 --> 00:14:40.720 And this is where the investigation shifted from a mystery 306 00:14:40.759 --> 00:14:45.519 of physics to a tragedy of human error. Investigators trace 307 00:14:45.559 --> 00:14:48.559 the aircraft tailed number seven oh one back to a 308 00:14:48.600 --> 00:14:52.159 maintenance hangar at the Houston Intercontinental Airport the night before 309 00:14:52.200 --> 00:14:52.759 the crash. 310 00:14:52.799 --> 00:14:53.799 What were they doing to it? 311 00:14:54.279 --> 00:14:57.200 Well? In preparation for winter, the crew had a ten 312 00:14:57.279 --> 00:15:00.799 hour overnight window to replace the rubber the ice boots 313 00:15:00.879 --> 00:15:03.399 on both the left and right sides of the horizontal 314 00:15:03.399 --> 00:15:04.519 stabilizer right. 315 00:15:04.639 --> 00:15:07.279 These d ice boots are pneumatic rubber bladders on the 316 00:15:07.360 --> 00:15:10.759 leading edges that inflate to break off ice during winter flights. 317 00:15:11.279 --> 00:15:14.360 To replace them, mechanics have to completely remove the leading 318 00:15:14.480 --> 00:15:17.759 edge to access the pneumatic lines, strip the old boot, 319 00:15:18.039 --> 00:15:20.120 glue the new one on, and screw the whole heavy 320 00:15:20.120 --> 00:15:21.600 assembly back onto the tail. 321 00:15:21.919 --> 00:15:24.639 Doing both sides is a massive job for one night shift, 322 00:15:24.960 --> 00:15:27.120 it really is, and they were heavily pressed for time. 323 00:15:27.320 --> 00:15:29.799 The mechanics were struggling to remove stripped screws on the 324 00:15:29.799 --> 00:15:32.279 bottom of the right side. This is where we meet 325 00:15:32.320 --> 00:15:35.519 an inspector named Troy Anderson. Seeing that the mechanics were 326 00:15:35.519 --> 00:15:38.720 falling behind, Anderson decided to climb up on a three 327 00:15:38.759 --> 00:15:41.879 story man lift and help out by removing the top 328 00:15:41.919 --> 00:15:43.360 screws on the left side of the tail. 329 00:15:43.440 --> 00:15:45.919 Wait, hold on, I'm putting myself in their shoes if 330 00:15:45.960 --> 00:15:48.960 they are behind schedule. Isn't teamwork a good thing? Like 331 00:15:49.279 --> 00:15:51.200 why wouldn't you want an extra pair of hands to 332 00:15:51.279 --> 00:15:53.080 help get a plane ready for the morning. 333 00:15:52.960 --> 00:15:56.919 In a normal office. Yes, in aviation maintenance, it is 334 00:15:56.960 --> 00:16:00.000 what we call the cardinal sin of structure. Really, oh yeah, 335 00:16:00.159 --> 00:16:03.879 the entire philosophy of aviation safety relies on rigid redundancy. 336 00:16:04.240 --> 00:16:07.080 You have one group, the mechanics, who are the doers 337 00:16:07.320 --> 00:16:10.559 they preferm the physical labor. Then you have an entirely separate, 338 00:16:10.799 --> 00:16:13.960 independent group, the inspectors, who are the checkers. 339 00:16:14.120 --> 00:16:16.000 Ah I say, their sole. 340 00:16:15.919 --> 00:16:18.559 Job is to verify that the work was done perfectly. 341 00:16:19.320 --> 00:16:22.039 By picking up a screwdriver and doing the physical labor himself, 342 00:16:22.279 --> 00:16:25.159 Anderson compromised his role. He could no longer be an 343 00:16:25.159 --> 00:16:28.480 independent set of eyes on that section of the plane. 344 00:16:28.120 --> 00:16:31.600 Because he stepped out of his designated role. This deadly 345 00:16:31.720 --> 00:16:36.799 chain of unseen errors began. So step one, Anderson removes 346 00:16:36.799 --> 00:16:39.399 the top screws on the left leading edge. He puts 347 00:16:39.399 --> 00:16:41.840 them in a little bag about forty screws and just 348 00:16:42.000 --> 00:16:44.720 leaves that bag sitting on top of the elevated man 349 00:16:44.759 --> 00:16:46.279 lift three stories up by the tail. 350 00:16:46.440 --> 00:16:49.440 Then step two involves the paperwork. In aviation, if it 351 00:16:49.480 --> 00:16:52.879 isn't documented, it didn't happen right. Mechanics are required to 352 00:16:52.879 --> 00:16:56.559 fill out shift work cards detailing exactly what parts were removed, 353 00:16:56.559 --> 00:16:58.879 so the next shift knows where to pick up. But 354 00:16:58.919 --> 00:17:01.519 Anderson wasn't a mechanic, he was an inspector, so he 355 00:17:01.559 --> 00:17:03.080 didn't do it. He figured he just took out a 356 00:17:03.120 --> 00:17:05.319 few screws to be helpful, and it wasn't worth the 357 00:17:05.359 --> 00:17:09.319 administrative hassle of filling out the labor cards, so he 358 00:17:09.400 --> 00:17:10.759 documented absolutely nothing. 359 00:17:11.000 --> 00:17:13.880 Then we hit step three, the shift change. It's ten 360 00:17:14.000 --> 00:17:17.039 years zero pm, the evening shift is clocking out and 361 00:17:17.119 --> 00:17:20.559 the midnight shift supervisor takes over. The mechanics realize they 362 00:17:20.599 --> 00:17:22.559 only have time to finish one side of the plane 363 00:17:22.559 --> 00:17:24.559 before the morning flight schedule. 364 00:17:24.279 --> 00:17:28.440 And this leads to the most critical tragic communication failure 365 00:17:28.480 --> 00:17:32.519 of the night. The midnight shift supervisor asks the departing 366 00:17:32.599 --> 00:17:35.119 evening shift, have you started on the left. 367 00:17:34.960 --> 00:17:38.000 Side yet, And because the evening mechanics had only worked 368 00:17:38.039 --> 00:17:40.640 on the bottom of the right side, and because Inspector 369 00:17:40.680 --> 00:17:43.359 Anderson hadn't filled out any paperwork documenting that he had 370 00:17:43.359 --> 00:17:46.720 removed the top screws on the left side, the evening 371 00:17:46.720 --> 00:17:50.680 supervisor looks at him and says, no, we haven't touched 372 00:17:50.759 --> 00:17:51.599 the left side. 373 00:17:51.880 --> 00:17:55.240 Operating on that false information, the midnight shift makes a 374 00:17:55.279 --> 00:17:58.759 fateful decision. They decide to forget the left side for 375 00:17:58.799 --> 00:18:01.440 the night, finish with lacing the boot on the right side, 376 00:18:01.720 --> 00:18:03.119 and get the plane out of the hangar. 377 00:18:03.279 --> 00:18:05.200 So they spend all night working on the right side. 378 00:18:05.200 --> 00:18:08.000 They reattach it perfectly, and then the plane is rolled 379 00:18:08.039 --> 00:18:11.240 out onto the tarmac for its morning flights. YEP sitting 380 00:18:11.240 --> 00:18:13.759 three stories up in the air, entirely out of sight 381 00:18:13.759 --> 00:18:16.559 from anyone standing on the ground. The left leading edge 382 00:18:16.559 --> 00:18:18.559 of the tail is resting in place, but it has 383 00:18:18.640 --> 00:18:21.480 absolutely no screws holding the top of it to the aircraft. 384 00:18:21.599 --> 00:18:23.960 It held together just long enough for the slower flight 385 00:18:24.000 --> 00:18:27.079 to Laredo, but the high speed descent back into Houston 386 00:18:27.200 --> 00:18:28.039 was the breaking point. 387 00:18:28.359 --> 00:18:31.799 It is genuinely hard to process this. It wasn't malice, 388 00:18:31.920 --> 00:18:35.279 wasn't sabotage. No mechanic woke up wanting to do a 389 00:18:35.279 --> 00:18:35.920 bad job. 390 00:18:36.119 --> 00:18:36.599 No not. 391 00:18:36.839 --> 00:18:41.240 It was a terrifying comedy of errors, a series of tiny, 392 00:18:41.359 --> 00:18:45.480 seemingly helpful shortcuts, and inspector deciding to lend a hand, 393 00:18:46.119 --> 00:18:48.920 a worker deciding to skip a tedious form for taking 394 00:18:48.920 --> 00:18:53.200 out a few screws, of verbal miscommunication during a shift change. 395 00:18:53.680 --> 00:18:57.640 Those tiny, invisible choices doomed fourteen people, and. 396 00:18:57.640 --> 00:19:01.319 This crash became a massive watershed moment in aviation history. 397 00:19:02.160 --> 00:19:05.960 When the NTSB released their final report, they did something unprecedented. 398 00:19:06.279 --> 00:19:08.119 For the first time ever. They didn't just point the 399 00:19:08.160 --> 00:19:09.920 finger at the mechanics on the hangar floor. 400 00:19:10.000 --> 00:19:10.839 They looked higher up. 401 00:19:11.000 --> 00:19:14.000