WEBVTT 1 00:00:00.160 --> 00:00:03.160 Welcome to the deep dive. Today, we're opening up a 2 00:00:03.160 --> 00:00:08.279 whole stack of official accident investigation reports, forensic metallurgy data, 3 00:00:08.359 --> 00:00:10.400 and salvaged cockpit recordings. 4 00:00:10.560 --> 00:00:13.759 Yeah, we are really getting into one of the most complex, 5 00:00:14.000 --> 00:00:17.839 just truly baffling aviation mysteries out there. 6 00:00:17.800 --> 00:00:21.160 Right, because our mission today is to piece together a 7 00:00:21.359 --> 00:00:26.760 terrifying puzzle like how does a massive commercial airliner end 8 00:00:26.839 --> 00:00:30.120 up totally obliterated in the desert raining debris over a 9 00:00:30.160 --> 00:00:32.920 twelve mile stretch just ten minutes after takeoff. 10 00:00:32.960 --> 00:00:34.880 It's hard to even wrap your head around that timeline 11 00:00:34.920 --> 00:00:36.079 ten minutes exactly. 12 00:00:36.479 --> 00:00:39.479 So to understand how a catastrophe of this magnitude unfolds, 13 00:00:39.479 --> 00:00:41.799 I want you to pixture this. You're standing on the 14 00:00:41.840 --> 00:00:43.960 tarmac in Jetta, Sudi Arabia. 15 00:00:43.679 --> 00:00:44.280 And it is hot. 16 00:00:44.359 --> 00:00:47.240 Oh, it is blistering. It's nineteen ninety one, and even 17 00:00:47.280 --> 00:00:49.520 though it is only eight point twenty six in the morning, 18 00:00:49.920 --> 00:00:52.520 the temperature has already crossed thirty degrees celsius. 19 00:00:52.640 --> 00:00:55.600 Right, So you've got heat waves literally shimmering off the concrete. 20 00:00:55.679 --> 00:00:59.280 Yeah, and the atmosphere around you is just electric. You're 21 00:00:59.320 --> 00:01:03.560 the Hodge Turneral, which is this colossal facility built exclusively 22 00:01:03.600 --> 00:01:06.319 for the annual Islamic pilgrimage to Mecca. 23 00:01:05.879 --> 00:01:09.680 And we are talking about a massive crowd. Over a 24 00:01:09.799 --> 00:01:12.280 million and a half pilgrims have gathered in the Holy 25 00:01:12.319 --> 00:01:12.920 City this week. 26 00:01:12.959 --> 00:01:14.439 It's just a sea of people. 27 00:01:14.599 --> 00:01:15.280 Mm hm. 28 00:01:15.280 --> 00:01:18.879 And you look out across this sprawling airfield and you 29 00:01:19.000 --> 00:01:23.120 see Nigeria Airways Flight twenty one twenty getting ready for departure. 30 00:01:23.239 --> 00:01:26.560 It's a huge DC eight commercial airliner. 31 00:01:26.159 --> 00:01:30.519 Right chartered by this scrappy Canadian startup airline called Nation Air, 32 00:01:31.079 --> 00:01:33.200 and it's getting ready to take ten hundred and forty 33 00:01:33.200 --> 00:01:35.000 seven Nigerian pilgrims. 34 00:01:34.480 --> 00:01:37.519 Back home, which is, you know, an incredibly profound moment 35 00:01:37.599 --> 00:01:39.760 for those passengers. I mean, for most of them coming 36 00:01:39.760 --> 00:01:42.840 from small rural villages in Nigeria, this is their very 37 00:01:42.879 --> 00:01:45.760 first time ever stepping foot on an airplane. 38 00:01:45.799 --> 00:01:46.159 Wow. 39 00:01:46.319 --> 00:01:49.840 Yeah, they're concluding this sacred, once in a lifetime journey. 40 00:01:50.120 --> 00:01:53.680 But as a historical record shows, none of those passengers 41 00:01:53.680 --> 00:01:55.760 and actually none of the fourteen crew members will ever 42 00:01:55.799 --> 00:01:56.319 make it home. 43 00:01:56.400 --> 00:01:58.519 Okay, let's unpack this because we need to start right 44 00:01:58.560 --> 00:02:00.719 at the beginning of the flight. The crew to navigate 45 00:02:00.760 --> 00:02:03.159 the sheer scale of the Jetta Airport just to get 46 00:02:03.159 --> 00:02:03.760 into position. 47 00:02:04.120 --> 00:02:06.879 Right, Captain Allen and First Officer Davis are upfront of 48 00:02:06.959 --> 00:02:12.240 the controls, and they are facing a grueling five kilometer 49 00:02:12.360 --> 00:02:15.719 taxi from the terminal all the way to the runway threshold. 50 00:02:15.840 --> 00:02:17.800 Five kilometers is a long way for a plane to 51 00:02:17.879 --> 00:02:18.479 just drive. 52 00:02:18.280 --> 00:02:21.800 On the ground, exactly. You have this heavy, fully loaded 53 00:02:21.800 --> 00:02:26.120 aircraft rolling across scorching hot tarmac for an extended period 54 00:02:26.159 --> 00:02:26.479 of time. 55 00:02:26.599 --> 00:02:26.759 Right. 56 00:02:26.919 --> 00:02:29.520 The physical stress on the landing gear during a taxi 57 00:02:29.560 --> 00:02:32.319 of that distance and that kind of extreme heat is 58 00:02:32.439 --> 00:02:33.080 just immense. 59 00:02:33.159 --> 00:02:36.000 So they finally line up. The first officer pushes the 60 00:02:36.039 --> 00:02:39.240 thrust to maximum, and the DC eight starts hurtling down 61 00:02:39.240 --> 00:02:42.439 the runway and gathering speed. But early in the takeoff roll, 62 00:02:42.599 --> 00:02:46.319 right around ninety knots, a really loud bang echoes through 63 00:02:46.319 --> 00:02:49.120 the cockpit just out of nowhere. Right. The flight engineer 64 00:02:49.159 --> 00:02:51.800 actually asks on the recording what's that? And the pilots 65 00:02:51.800 --> 00:02:53.680 feel this distinct shimmy, like. 66 00:02:54.439 --> 00:02:56.919 Driving your car over a patch of really deeply rutted 67 00:02:56.960 --> 00:02:58.120 asphalt exactly. 68 00:02:58.159 --> 00:03:01.199 But the instruments in the cockpit show absolutely no indication 69 00:03:01.280 --> 00:03:02.120 of trouble. 70 00:03:01.879 --> 00:03:04.800 Nothing at all. There are no warning lights no hydraulic 71 00:03:04.800 --> 00:03:08.439 pressure drops, no system failures popping up on the main panel. 72 00:03:08.319 --> 00:03:11.159 Which is wild. So the crew assesses the situation in 73 00:03:11.199 --> 00:03:14.159 a split second and they just continue to accelerate down 74 00:03:14.199 --> 00:03:15.080 the runway. 75 00:03:14.719 --> 00:03:17.159 Which makes sense to them in that exact moment. 76 00:03:17.280 --> 00:03:19.599 Well, I have to pause here because I know you 77 00:03:19.680 --> 00:03:21.840 listening to this are probably thinking the exact same thing 78 00:03:21.879 --> 00:03:22.240 I am. 79 00:03:22.439 --> 00:03:24.599 Oh about hitting the brakes. 80 00:03:24.759 --> 00:03:27.280 Yeah, if I'm driving down the highway at highway speeds 81 00:03:27.560 --> 00:03:30.400 and I hear a massive bang and feel my entire 82 00:03:30.520 --> 00:03:33.599 car violently shimmy, I hit the brakes. 83 00:03:33.400 --> 00:03:34.800 Right, you pull over immediately. 84 00:03:35.000 --> 00:03:37.879 Why on earth wouldn't a pilot just abort the takeoff, 85 00:03:38.000 --> 00:03:40.520 stop the plane and figure out what just happened. 86 00:03:40.599 --> 00:03:44.400 Well, the physics of a fully loaded commercial airliner dictate 87 00:03:44.439 --> 00:03:47.680 a completely different set of survival rules than a car. Okay, 88 00:03:48.120 --> 00:03:51.800 As they accelerate, the crew is constantly monitoring their speed, 89 00:03:52.240 --> 00:03:55.879 watching for this critical threshold called V one the one right, Yeah. 90 00:03:55.960 --> 00:03:58.800 V one is the takeoff decision speed. It's a highly 91 00:03:58.840 --> 00:04:02.240 specific mathematical calculation based on the way of the aircraft, 92 00:04:02.479 --> 00:04:04.840 the length of the runway, and the outside temperature. 93 00:04:04.960 --> 00:04:07.840 So it changes for every single flight. 94 00:04:08.000 --> 00:04:11.319 Exactly and once an aircraft hits V one, the kinetic 95 00:04:11.479 --> 00:04:15.199 energy involved is so massive that the brakes simply cannot 96 00:04:15.240 --> 00:04:17.639 absorb the heat required to stop the plane before the 97 00:04:17.720 --> 00:04:18.360 runway ends. 98 00:04:19.000 --> 00:04:21.240 So if they just slammed on the brakes after V one, 99 00:04:21.399 --> 00:04:22.839 what physically happens to the. 100 00:04:22.839 --> 00:04:26.199 Aircraft it would be a disaster. The break assemblies would 101 00:04:26.279 --> 00:04:28.720 instantly exceed their thermal limits and melt. 102 00:04:28.879 --> 00:04:29.319 Oh wow. 103 00:04:29.480 --> 00:04:31.920 Yeah, the tires would likely explode just from the sheer 104 00:04:31.920 --> 00:04:34.399 heat of the friction, and the aircraft would end up 105 00:04:34.439 --> 00:04:36.279 skidding off the end of the runway at over one 106 00:04:36.319 --> 00:04:39.360 hundred miles per hour, plowing into whatever terrain is out 107 00:04:39.360 --> 00:04:40.399 there beyond the tarmac. 108 00:04:40.639 --> 00:04:41.639 That is terrifying. 109 00:04:41.759 --> 00:04:44.399 It is so it's physically safer to force the plane 110 00:04:44.399 --> 00:04:48.199 into the air than to attempt an impossible stock And furthermore, 111 00:04:48.319 --> 00:04:51.160 based on that shimmy, they felt the crew suspects they 112 00:04:51.240 --> 00:04:54.360 might have just blown a tire, which happens, right, Yeah, 113 00:04:54.399 --> 00:04:58.160 Blowing a tire is something commercial landing gear is absolutely 114 00:04:58.160 --> 00:05:01.800 designed to handle, got it. So the standard safest protocol 115 00:05:01.839 --> 00:05:04.120 is exactly what they did. You take off, get to 116 00:05:04.160 --> 00:05:07.160 a safe altitude, burn off heavy fuel if you need to, 117 00:05:07.199 --> 00:05:08.839 and circle back to land safely. 118 00:05:09.160 --> 00:05:12.079 Okay, So they rotate, they lift off, and just ninety 119 00:05:12.079 --> 00:05:15.639 seconds into the flight, the crew retracts the landing. 120 00:05:15.360 --> 00:05:17.759 Gear, right standard procedure, but. 121 00:05:17.920 --> 00:05:21.560 Almost immediately, alarms just flood the cockpit. 122 00:05:21.720 --> 00:05:22.439 It's chaos. 123 00:05:22.519 --> 00:05:26.040 The flight engineer calls out four separate low pressure lights. 124 00:05:27.120 --> 00:05:32.120 Then a spoiler light illuminates, followed by a gear unsafe warning. 125 00:05:32.560 --> 00:05:34.680 So you have to put yourself in the mindset of 126 00:05:34.720 --> 00:05:37.399 the pilots trying to troubleshoot this in real time. 127 00:05:37.519 --> 00:05:38.959 Yeah, they must be so confused. 128 00:05:39.160 --> 00:05:43.000 They're seeing a very specific, strange combination of warning lights, 129 00:05:43.639 --> 00:05:46.480 and based on their training and the instrument panel, they 130 00:05:46.519 --> 00:05:49.600 conclude they're experiencing a pressurization issue. 131 00:05:49.720 --> 00:05:51.560 Okay, why pressurization. 132 00:05:51.279 --> 00:05:54.360 Because they believe the cabin isn't sealing correctly, which can 133 00:05:54.439 --> 00:05:57.759 trigger all these various pneumatic system warnings. They have absolutely 134 00:05:57.839 --> 00:06:00.720 no idea what is actually unfolding right beneath their feet. 135 00:06:00.959 --> 00:06:04.319 Will the pilots are working through their pressurization checklists upfront, 136 00:06:04.879 --> 00:06:08.319 the reality back in the passenger cabin is rapidly deteriorating. 137 00:06:08.360 --> 00:06:09.519 It's turning into a nightmare. 138 00:06:09.720 --> 00:06:14.600 Less than three minutes after takeoff, thick choking smoke begins 139 00:06:14.759 --> 00:06:19.160 billowing up through the floorboards directly into the passenger seating area, and. 140 00:06:19.199 --> 00:06:22.560 Passengers are panicking. They're leaving their seats and rushing forward 141 00:06:22.639 --> 00:06:25.600 toward the front of the cabin, just desperate for breathable air. 142 00:06:26.079 --> 00:06:30.199 Now there happens to be a Nationaire lead mechanic on board, Jean. 143 00:06:29.959 --> 00:06:32.079 Paul Philippe right he was traveling with them. 144 00:06:32.120 --> 00:06:34.680 The cockpit crew asks him to go back and investigate 145 00:06:35.079 --> 00:06:37.879 because someone in the front mentions smelling smoke. 146 00:06:37.879 --> 00:06:39.040 So he goes to check it out. 147 00:06:39.079 --> 00:06:42.040 He steps out of the flight deck, walks back and 148 00:06:42.120 --> 00:06:47.519 immediately realizes the terrifying truth. This isn't a pressurization glitch. 149 00:06:47.399 --> 00:06:48.240 No, all. 150 00:06:48.279 --> 00:06:50.600 The plane is actively burning from the inside out. 151 00:06:50.720 --> 00:06:53.000 But the pilots up front they are completely unaware of 152 00:06:53.000 --> 00:06:56.279 the inferno raging behind them, so they radio the air 153 00:06:56.319 --> 00:06:59.639 traffic control tower in Jetta to clear an emergency. They 154 00:06:59.680 --> 00:07:02.600 inform the tower they're having a pressurization problem and requests 155 00:07:02.639 --> 00:07:04.839 clearance to level off at two thousand feet so they 156 00:07:04.879 --> 00:07:07.199 can stabilize and return to the airport. 157 00:07:07.360 --> 00:07:10.480 And this brings us to a fatal coincidence that just 158 00:07:10.920 --> 00:07:12.720 severely worsens the crisis. 159 00:07:13.040 --> 00:07:14.800 It really is unbelievable. 160 00:07:14.920 --> 00:07:18.600 The air traffic controller agrees to the altitude hold, but 161 00:07:19.160 --> 00:07:22.199 there is this catastrophic misunderstanding on the radar screen. 162 00:07:22.319 --> 00:07:24.800 The controller thinks he's talking to a completely different airplane. 163 00:07:24.879 --> 00:07:28.160 Yes, he believes he is talking to Saudi Arabian flight 164 00:07:28.240 --> 00:07:31.879 seven thirty eight, which you can't make this up, is 165 00:07:31.959 --> 00:07:36.560 experiencing an identical pressurization problem in the exact same airspace 166 00:07:36.639 --> 00:07:38.000 at the exact same moment. 167 00:07:38.240 --> 00:07:40.199 The odds of that are just staggering. 168 00:07:40.439 --> 00:07:43.240 So the controller gives flight twenty one to twenty instructions 169 00:07:43.279 --> 00:07:46.439 meant for the Saudi plane. He commands the burning dcaight 170 00:07:46.480 --> 00:07:48.879 to climb to three thousand feet and to turn to 171 00:07:48.920 --> 00:07:49.959 a heading of one sixty. 172 00:07:50.079 --> 00:07:52.839 And heading one sixty makes zero sense for a plane 173 00:07:52.959 --> 00:07:54.279 trying to land right. 174 00:07:54.480 --> 00:07:56.240 It is like calling nine one one from inside a 175 00:07:56.279 --> 00:07:59.839 burning house, But the dispatcher gets their lines crossed, assumes 176 00:07:59.879 --> 00:08:02.399 you or a different caller dealing with a flooded basement, 177 00:08:02.959 --> 00:08:05.360 and gives you instructions that pull you away from safety 178 00:08:05.360 --> 00:08:06.639 instead of sending a fire truck. 179 00:08:06.759 --> 00:08:08.600 That's the perfect way to put it. The tower and 180 00:08:08.639 --> 00:08:12.800 the pilots are inadvertently making a dire situation exponentially worse. 181 00:08:13.079 --> 00:08:16.120 Flight twenty one twenty is now thirteen kilometers away from 182 00:08:16.120 --> 00:08:19.839 the airport, flying in the wrong direction, all while this 183 00:08:20.079 --> 00:08:24.759 massive fire violently consumes the structural integrity of the aircraft. 184 00:08:24.279 --> 00:08:27.519 And the fire eats right through the hydraulic lines controlling the. 185 00:08:27.399 --> 00:08:29.800 Alerons right the flight controls, so. 186 00:08:29.839 --> 00:08:32.600 Without those flaps on the wings working to bank the plane, 187 00:08:33.080 --> 00:08:36.000 the pilots are completely unable to turn the aircraft back 188 00:08:36.000 --> 00:08:36.720 toward the runway. 189 00:08:37.519 --> 00:08:41.480 To understand the physical toll of that failure, imagine driving 190 00:08:41.519 --> 00:08:45.120 a massive semi truck down a steep mountain pass ok 191 00:08:45.639 --> 00:08:49.559 and suddenly your power steering fluid drains out completely. The 192 00:08:49.600 --> 00:08:52.679 steering wheel is physically connected to the tires, sure, but 193 00:08:52.799 --> 00:08:55.200 the sheer weight and force of the road make it 194 00:08:55.200 --> 00:08:57.360 almost impossible for human arms to turn it. 195 00:08:57.399 --> 00:08:59.720 You're essentially fighting the entire mass of the vehicle with 196 00:08:59.759 --> 00:09:01.320 your own shoulders exactly. 197 00:09:01.639 --> 00:09:04.639 Now, multiply that aerodynamic force by one hundred A DC 198 00:09:04.759 --> 00:09:07.480 eight is flying at two hundred and fifty knots. The 199 00:09:07.519 --> 00:09:11.200 air resistance pushing against those giant metal control surfaces on 200 00:09:11.240 --> 00:09:12.600 the wings is immense. 201 00:09:12.720 --> 00:09:13.559 Yeah, that makes sense. 202 00:09:13.720 --> 00:09:17.559 The hydraulic system exists to multiply human input by thousands 203 00:09:17.600 --> 00:09:21.440 of pounds of force. Without it, Captain Allen is essentially 204 00:09:21.480 --> 00:09:24.639 trying to push against hurricane force winds with his bare hands. 205 00:09:24.679 --> 00:09:27.840 It's impossible, but they finally manage to communicate their true 206 00:09:27.879 --> 00:09:29.039 identity to the tower. 207 00:09:29.279 --> 00:09:30.919 Right the confusion clears up. 208 00:09:30.840 --> 00:09:34.840 The controller realizes his mistake and immediately clears them to 209 00:09:34.960 --> 00:09:39.000 land on any runway. But as they limp back over 210 00:09:39.000 --> 00:09:41.279 the city of Jetta, which by the way, is a 211 00:09:41.320 --> 00:09:42.720 city of two million people. 212 00:09:42.799 --> 00:09:45.000 It's a huge, densely populated area. 213 00:09:45.120 --> 00:09:47.759 The heat inside the cabin becomes so intense that the 214 00:09:47.799 --> 00:09:51.720 floorboards literally warp and melt away. Eleven miles out from 215 00:09:51.720 --> 00:09:55.200 the airport, bodies literally begin falling from the fuselage. 216 00:09:55.279 --> 00:09:57.840 It's just horrific, and two miles from the runway. Desperate 217 00:09:57.879 --> 00:10:00.039 to make the threshold, the captain lowers the landing. 218 00:09:59.759 --> 00:10:03.200 Gear, which seems like the right move, but the fire. 219 00:10:03.039 --> 00:10:06.200 Has so severely compromised the airframe at this point, the 220 00:10:06.240 --> 00:10:09.200 physical force of that heavy landing gear deploying into the 221 00:10:09.240 --> 00:10:13.519 airstream acts as the final blow to the plane's structural integrity. 222 00:10:13.600 --> 00:10:14.919 The airframe just shatters. 223 00:10:15.159 --> 00:10:15.600 It does. 224 00:10:15.919 --> 00:10:19.399 The plane loses all forward flight capability and crashes into 225 00:10:19.440 --> 00:10:22.840 the desert, instantly, killing all two hundred and forty seven 226 00:10:22.879 --> 00:10:24.960 passengers and the fourteen crew members. 227 00:10:25.080 --> 00:10:28.840 Yeah. To this day, it remains the deadliest DC eight 228 00:10:28.919 --> 00:10:32.600 crash in aviation history and the deadliest accident ever for 229 00:10:32.679 --> 00:10:33.840 a Canadian airline. 230 00:10:33.879 --> 00:10:37.559 So a team of Canadian investigators, including technical expert Bill 231 00:10:37.559 --> 00:10:41.080 Taylor and lead investigator ron Coleman, arrive in Jetta a 232 00:10:41.159 --> 00:10:43.720 day later to assist the Saudi authorities. 233 00:10:43.240 --> 00:10:45.320 And they are met with just total devastation. 234 00:10:45.679 --> 00:10:49.200 The main wreckage sprawls across four hundred meters of desert, 235 00:10:49.279 --> 00:10:51.200 completely charred. 236 00:10:50.759 --> 00:10:53.240 But because the plane broke apart mid air, the debris 237 00:10:53.240 --> 00:10:55.919 field isn't limited to that one crash site. 238 00:10:55.720 --> 00:10:58.919 Right It stretches for twelve miles. So an investigator stand 239 00:10:58.960 --> 00:11:02.399 in the middle of this un recognizable blackened metal. Their 240 00:11:02.440 --> 00:11:06.559 primary mandate is to answer one fundamental question, where did 241 00:11:06.600 --> 00:11:07.440 the fire start. 242 00:11:07.559 --> 00:11:10.120 What's fascinating here is that the forensics of metallurgy can 243 00:11:10.159 --> 00:11:13.279 tell a story even when everything is reduced to ash. 244 00:11:13.320 --> 00:11:16.960 Really how well the investigators have to distinguish between parts 245 00:11:17.000 --> 00:11:18.759 of the plane that burn while it was falling through 246 00:11:18.799 --> 00:11:20.639 the air and parts that burned on the ground after 247 00:11:20.639 --> 00:11:21.320 the crash. 248 00:11:21.399 --> 00:11:25.080 Okay, tell me how investigators differentiate those two types of 249 00:11:25.080 --> 00:11:25.960 fire damage. 250 00:11:26.080 --> 00:11:29.000 They look for a phenomenon known as the blow torch effect. 251 00:11:29.559 --> 00:11:32.200 A fire that happens on the ground leaves a relatively 252 00:11:32.279 --> 00:11:35.840 even coating of soot and melted material, and that molten 253 00:11:35.879 --> 00:11:39.360 metal drips straight down due to gravity. Makes sense, But 254 00:11:39.559 --> 00:11:44.000 an in flight fire behaves vastly differently. It's constantly fed 255 00:11:44.039 --> 00:11:47.360 and shaped by two hundred and forty nine winds. The 256 00:11:47.399 --> 00:11:50.720 slipstream forces the flame to act exactly like a forced 257 00:11:50.720 --> 00:11:52.240 induction furnace, so. 258 00:11:52.240 --> 00:11:55.039 The wind is pushing the flames backward at speeds far 259 00:11:55.120 --> 00:11:57.639 exceeding a Category five hurricane. 260 00:11:57.320 --> 00:12:01.480 Exactly that extreme friction and focus heat melt the aluminum 261 00:12:01.519 --> 00:12:04.120 structure of the plane, which has a melting point of 262 00:12:04.159 --> 00:12:06.120 around eleven hundred degrees celsius. 263 00:12:06.159 --> 00:12:06.559 Wow. 264 00:12:06.720 --> 00:12:09.360 The wind catches that molten aluminum and sprays it backward. 265 00:12:09.679 --> 00:12:12.360 The investigators discovered that the tail section of the airplane 266 00:12:12.360 --> 00:12:15.639 was completely coated in this blown molten aluminum. 267 00:12:15.120 --> 00:12:17.080 Painting a clear picture of the airflow right. 268 00:12:17.320 --> 00:12:20.039 Furthermore, when they analyzed the center fuel cell, they found 269 00:12:20.080 --> 00:12:23.159 a clear distinct burned through pattern on the forward. 270 00:12:22.799 --> 00:12:26.320 Wall, meaning the fire definitively started mid air, right in 271 00:12:26.360 --> 00:12:31.000 the center belly of the plane, inside the wheelwell exactly. Now, 272 00:12:31.080 --> 00:12:33.440 nation are publicly claims the plane must have hit a 273 00:12:33.440 --> 00:12:36.679 foreign object like a piece of metal debris on the runway, 274 00:12:36.879 --> 00:12:40.519 which punctured the tires and caused the catastrophe. 275 00:12:39.919 --> 00:12:43.559 But the Saudi aviation authorities strongly deny that claim. They 276 00:12:43.639 --> 00:12:46.840 insist the runway was completely clear of debris. 277 00:12:46.480 --> 00:12:50.000 Which creates this really tense standoff over liability. 278 00:12:50.120 --> 00:12:53.159 Yeah, a massive corporate and international dispute. 279 00:12:53.480 --> 00:12:56.120 But the breakthrough comes from the most fragile piece of 280 00:12:56.159 --> 00:13:00.799 evidence imaginable. Investigator Bill Taylor is walking the crash site 281 00:13:00.799 --> 00:13:03.320 in the desert and he spots a single piece of 282 00:13:03.320 --> 00:13:04.759 paper blowing across the sand. 283 00:13:04.960 --> 00:13:07.240 It is incredible that a piece of paper survived an 284 00:13:07.320 --> 00:13:09.600 inferno that melted aluminum. 285 00:13:09.639 --> 00:13:12.240 I know, it's basically a miracle. He picks it up 286 00:13:12.440 --> 00:13:14.440 and it turns out to be part of the aircraft's 287 00:13:14.480 --> 00:13:18.559 a flight inspection checklist, a crucial documents. Specifically, it's the 288 00:13:18.600 --> 00:13:22.399 exact page where the mechanics record the tire pressures, and 289 00:13:22.480 --> 00:13:24.759 Taylor notices that there are two different colors of ink 290 00:13:25.080 --> 00:13:28.440 on the tire pressure entries. Someone had clearly written over 291 00:13:28.480 --> 00:13:32.480 the original numbers, So they send this single salvaged piece 292 00:13:32.519 --> 00:13:36.240 of paper back to the Royal Canadian Mounted Police forensics lab. 293 00:13:36.879 --> 00:13:39.480 But how does a lab pull original numbers from a 294 00:13:39.519 --> 00:13:42.159 piece of paper that's been scribbled over and left in 295 00:13:42.200 --> 00:13:42.639 a desert. 296 00:13:42.840 --> 00:13:46.960 The RCMPD document examiners use a technique involving infrared imaging. 297 00:13:47.240 --> 00:13:49.120 Oh like special cameras. 298 00:13:48.799 --> 00:13:52.960 Exactly different inks are manufactured with different chemical compositions, even 299 00:13:53.000 --> 00:13:55.120 if they look like the exact same shade of blue 300 00:13:55.200 --> 00:13:58.200 or black to the naked eye. Okay, so under specific 301 00:13:58.240 --> 00:14:02.480 wavelengths of infrared light, one ink might become completely transparent 302 00:14:02.840 --> 00:14:05.840 while the other absorbs the light and appears pitch black. 303 00:14:06.000 --> 00:14:09.639 That's brilliant. So when the forensic team put this checklist 304 00:14:09.720 --> 00:14:13.279 under the camera, the top layer of scribbled ink just vanished, 305 00:14:13.679 --> 00:14:16.799 revealing the original numbers written underneath perfectly clearly. 306 00:14:16.960 --> 00:14:20.240 And those original tire pressure readings were dangerously low. 307 00:14:20.120 --> 00:14:23.200 Yeah, twenty to thirty psi below the minimum safe level. 308 00:14:23.480 --> 00:14:26.759 Someone had literally falsified the maintenance logs to make the 309 00:14:26.799 --> 00:14:28.679 plane's tires look fit to fly. 310 00:14:28.799 --> 00:14:31.840 And because the plane was utterly destroyed on impact, the 311 00:14:31.919 --> 00:14:35.159 investigators couldn't rely on the physical wreckage to explain the 312 00:14:35.159 --> 00:14:37.679 initial failure. They had to work backward based on this 313 00:14:37.759 --> 00:14:39.039 altered document. 314 00:14:38.840 --> 00:14:41.679 So they track the plane's movements to a layover four 315 00:14:41.759 --> 00:14:45.159 days prior in Ghana. In Ghana, the mechanics on the 316 00:14:45.159 --> 00:14:47.159 ground see that the tires are wearing down and the 317 00:14:47.200 --> 00:14:50.639 pressure is low. They prepared to change the wheels, which 318 00:14:50.679 --> 00:14:53.200 is the correct safe protocol, But before. 319 00:14:52.919 --> 00:14:55.600 They can even initiate the maintenance, a fax comes in 320 00:14:55.600 --> 00:14:59.200 from the Nationaire project manager stationed in Jetta. 321 00:14:58.720 --> 00:15:02.159 And the facts orders them to stop the tire change immediately. 322 00:15:02.960 --> 00:15:05.759 The manager states they are behind schedule, risking their charter 323 00:15:05.879 --> 00:15:08.759 contract and orders the crew to just load the plane 324 00:15:08.759 --> 00:15:09.720 and fly it as is. 325 00:15:09.919 --> 00:15:13.000 See, nation Air was operating under this really intense culture 326 00:15:13.039 --> 00:15:16.200 that prioritize speed and cost saving above all else. 327 00:15:16.399 --> 00:15:19.120 Right, a tire change meant to delay, and a delay 328 00:15:19.159 --> 00:15:20.000 meant lost. 329 00:15:19.759 --> 00:15:23.639 Profits exactly, and the decision to skip the tire change 330 00:15:23.639 --> 00:15:26.679 in Ghana directly creates the crisis on the morning of 331 00:15:26.720 --> 00:15:28.159 the fatal flight in Jeta. 332 00:15:28.320 --> 00:15:31.000 Because lead mechanic Jean Paul Fleiep is doing his pre 333 00:15:31.120 --> 00:15:35.039 flight checks in Jetta, he knows the tires desperately need 334 00:15:35.080 --> 00:15:35.759 to be topped up. 335 00:15:36.000 --> 00:15:39.000 But airplane tires are not filled with regular air. They 336 00:15:39.039 --> 00:15:44.120 require nitrogen. Right, regular compressed air contains oxygen, and oxygen 337 00:15:44.320 --> 00:15:48.600 is a powerful oxidizer, meaning it actively feeds and accelerates 338 00:15:48.600 --> 00:15:50.279 fire when it's introduced to high heat. 339 00:15:50.519 --> 00:15:53.720 So you definitely don't want that inside a high friction dot. 340 00:15:53.720 --> 00:15:57.000 Now you want nitrogen. Nitrogen is an inert gas. It 341 00:15:57.320 --> 00:16:02.159 smothers combustion and does not expand unpredictably under extreme temperature changes. 342 00:16:02.240 --> 00:16:04.879 The Philip desperately tries to find nitrogen to fill the 343 00:16:04.919 --> 00:16:08.600 tires before takeoff. He asks other airlines for help, but 344 00:16:08.679 --> 00:16:11.759 the local supply tanks and jetta are entirely empty. 345 00:16:11.879 --> 00:16:13.919 And this is where the project manager steps in again. 346 00:16:14.000 --> 00:16:15.840 Right, the guy who isn't a pilot, nor is he 347 00:16:15.879 --> 00:16:16.759 a trained mechanic. 348 00:16:16.960 --> 00:16:19.600 He focuses solely on the departure schedule, and he orders 349 00:16:19.600 --> 00:16:22.240 Philipe to forget the nitrogen and just fly the plane 350 00:16:22.320 --> 00:16:23.440 exactly as it sits. 351 00:16:23.480 --> 00:16:27.240 And the deadly physics of that management decision completely sealed 352 00:16:27.279 --> 00:16:28.279 the fate of the aircraft. 353 00:16:28.480 --> 00:16:31.320 Yeah, let's look at a DC eight's main landing gear. 354 00:16:31.879 --> 00:16:34.360 It has a left and right bogie, and each one 355 00:16:34.399 --> 00:16:38.720 contains four wheels. Okay, Uniform tire pressure across those wheels 356 00:16:38.799 --> 00:16:42.039 is absolutely critical to ensure the massive weight of a 357 00:16:42.039 --> 00:16:45.240 fully loaded airliner is distributed evenly. 358 00:16:45.759 --> 00:16:48.399 Because of the falsified log in Ghana and the skip 359 00:16:48.519 --> 00:16:53.279 nitrogen top up in Jeta, one tire is severely underinflated. 360 00:16:53.519 --> 00:16:56.440 The investigation calculated it was sitting at one fifty five 361 00:16:56.559 --> 00:17:00.840 psi instead of the mandatory one eight three ps Right. 362 00:17:01.000 --> 00:17:04.960 And an underinflated tire cannot physically carry its designated share 363 00:17:05.000 --> 00:17:05.519 of the burden. 364 00:17:05.680 --> 00:17:08.039 It just squishes under the weight exactly. 365 00:17:07.799 --> 00:17:10.400 So the extreme weight of the aircraft is immediately transferred 366 00:17:10.440 --> 00:17:13.119 to the adjacent tire on the exact same axle. Oh, 367 00:17:13.160 --> 00:17:16.000 I see that single good tire is now bearing double 368 00:17:16.039 --> 00:17:17.839 the weight it was engineered to handle. 369 00:17:17.960 --> 00:17:20.920 Wow. So combine that overloaded tire with the five kilometer 370 00:17:21.039 --> 00:17:24.559 taxi across a scorching desert tarmac. They're rolling for over 371 00:17:24.599 --> 00:17:27.079 ten minutes with double the weight pressing down on one 372 00:17:27.079 --> 00:17:27.839 side of the axle. 373 00:17:27.960 --> 00:17:30.240 The heat of the tarmac and the excessive weight caused 374 00:17:30.279 --> 00:17:32.799 the nylon cords inside that overloaded tire to. 375 00:17:32.759 --> 00:17:34.720 Over deflect, meaning it bends too much. 376 00:17:35.039 --> 00:17:40.519 Yes, the tire bends and flexes excessively with every single rotation. 377 00:17:41.519 --> 00:17:46.240 This internal friction generates massive heat inside the rubber, eventually 378 00:17:46.279 --> 00:17:48.599 causing the nylon structure to melt, so. 379 00:17:48.640 --> 00:17:51.839 That good tire simply gives up and detonates under the 380 00:17:51.839 --> 00:17:55.039 pressure it does. But if the one good tire explodes, 381 00:17:55.440 --> 00:17:57.759 what happens to the underinflated one. They couldn't handle the 382 00:17:57.759 --> 00:17:58.440 weight to begin with. 383 00:17:58.680 --> 00:18:01.039 It is instantly crushed by the entire weight of that 384 00:18:01.079 --> 00:18:03.440 side of the aircraft. It blows a fraction of a 385 00:18:03.480 --> 00:18:04.279 second later. 386 00:18:04.480 --> 00:18:08.640 Which leads the bare metal wheel rim scraping directly against 387 00:18:08.680 --> 00:18:10.680 the runway at high takeoff speeds. 388 00:18:10.799 --> 00:18:13.720 Right, and the friction of metal grinding on tarmac at 389 00:18:13.759 --> 00:18:16.640 one hundred and fifty miles per hour generates a continuous 390 00:18:16.680 --> 00:18:18.799 shower of superheated sparks. 391 00:18:18.519 --> 00:18:21.240 And that heat is more than enough to ignite the shredded, 392 00:18:21.400 --> 00:18:23.640 oxygen riish rubber of the destroyed tires. 393 00:18:23.759 --> 00:18:26.000 Remember they didn't have nitrogen in there to smother it. 394 00:18:26.119 --> 00:18:28.920 The crew up front, here's the bang, but they have 395 00:18:29.000 --> 00:18:31.160 no idea they are dragging a flaming wheel. 396 00:18:31.200 --> 00:18:33.160 They just think it's a blowout, so they. 397 00:18:33.039 --> 00:18:36.599 Lift off, follow their training for a suspected blowout, and 398 00:18:36.720 --> 00:18:40.640 retract the landing gear. They pull a massive, burning hunk 399 00:18:40.640 --> 00:18:43.440 of rubber directly up into the belly of the aircraft, and. 400 00:18:43.400 --> 00:18:46.640 The wheel well is arguably the worst possible place for 401 00:18:46.680 --> 00:18:49.240