1 00:00:03,144 --> 00:00:04,520 Korean Air Flight 6316, 2 00:00:04,520 --> 00:00:07,315 now turn left direct to November, Hotel, Whiskey. 3 00:00:07,315 --> 00:00:08,858 Where is it? 4 00:00:08,858 --> 00:00:11,778 The pilots of Korean Air 6316 struggle to navigate 5 00:00:11,778 --> 00:00:14,739 in the skies above Shanghai, China. 6 00:00:14,739 --> 00:00:16,949 Keep turning left. Keep turning. 7 00:00:16,949 --> 00:00:17,867 Keep turning? 8 00:00:18,576 --> 00:00:20,703 The controller really needs the aircraft 9 00:00:20,703 --> 00:00:23,122 to be going on the expected path. 10 00:00:23,122 --> 00:00:25,833 - But seconds later... - Nose up. Nose up. Nose up. 11 00:00:25,833 --> 00:00:30,630 ...the M-D-11-F crashes near a residential neighbourhood. 12 00:00:31,214 --> 00:00:33,257 The impact registered the equivalent 13 00:00:33,257 --> 00:00:35,301 of a 1.6 earthquake. 14 00:00:36,052 --> 00:00:39,847 When investigators reconstruct the flight in a simulator... 15 00:00:39,847 --> 00:00:43,851 Start the dive in three, two, one, go. 16 00:00:43,851 --> 00:00:46,396 ...they come to a shocking realization. 17 00:00:46,396 --> 00:00:50,274 The data showed that the upset was caused by a pilot input. 18 00:00:50,274 --> 00:00:51,901 And that becomes the mystery. 19 00:01:18,428 --> 00:01:21,806 {\an8}It's a mild and overcast spring day 20 00:01:21,806 --> 00:01:25,685 {\an8}at Hongqiao International Airport in Shanghai, China. 21 00:01:28,896 --> 00:01:33,151 {\an8}Korean Air Flight 6316 is being prepared for departure. 22 00:01:33,151 --> 00:01:39,449 The cargo plane is loaded with 86 tons of non-hazardous materials. 23 00:01:40,324 --> 00:01:42,618 Checklist beacon light. 24 00:01:42,618 --> 00:01:45,163 Before Start checklist, sir. 25 00:01:45,913 --> 00:01:49,584 The Captain is 54-year-old Hong Sung Sil... 26 00:01:49,876 --> 00:01:52,211 {\an8}Captain Hong is a very experienced pilot 27 00:01:52,211 --> 00:01:57,216 {\an8}with 13,000 flight hours and a very good safety record. 28 00:01:57,550 --> 00:02:02,346 ...today his First Officer is 35-year-old Park Bon-Suk. 29 00:02:02,346 --> 00:02:05,808 First Officer Park is less experienced than the captain 30 00:02:05,808 --> 00:02:08,644 but also has an excellent safety record. 31 00:02:12,023 --> 00:02:15,443 - Doors and windows? - Closed and locked. 32 00:02:16,944 --> 00:02:20,198 Korean Air is South Korea's flag carrier. 33 00:02:20,198 --> 00:02:25,078 Its headquarters is located at Gimpo International Airport in Seoul. 34 00:02:25,912 --> 00:02:31,918 In 1999 Korean Air is one of the top three passenger airlines in Asia. 35 00:02:31,918 --> 00:02:35,880 And its cargo division is top three in the world. 36 00:02:36,756 --> 00:02:41,094 Its routes covered Asia, South America and Europe. 37 00:02:46,391 --> 00:02:49,018 Hey, guys. Any issues or concerns? 38 00:02:49,602 --> 00:02:50,978 All good so far. 39 00:02:51,437 --> 00:02:56,317 Also on board is 48-year-old Flight Technician Park Byong-Ki. 40 00:02:56,818 --> 00:03:02,490 The flight tech is a mechanic onboard who is not a part of the flight crew. 41 00:03:02,490 --> 00:03:05,910 His job is just to make sure this aircraft 42 00:03:05,910 --> 00:03:09,956 has no mechanic issue and will take off safely. 43 00:03:11,249 --> 00:03:13,042 Engine ignition? 44 00:03:13,042 --> 00:03:18,089 Standby. Fuel panel, auto. 45 00:03:18,089 --> 00:03:21,217 Air panel, auto. 46 00:03:21,217 --> 00:03:23,344 Before start checks complete. 47 00:03:23,344 --> 00:03:26,556 Before the aircraft can begin taxiing to the runway, 48 00:03:26,556 --> 00:03:29,392 it must be pushed into position on the taxiway. 49 00:03:29,392 --> 00:03:33,062 Captain, can you release the parking brake? 50 00:03:33,688 --> 00:03:35,565 Okay, brake released. 51 00:03:38,359 --> 00:03:41,487 All aircraft are parked facing terminal 52 00:03:41,487 --> 00:03:47,201 or the cargo apron, which means the aircraft has no ability to reverse by themselves. 53 00:03:47,201 --> 00:03:51,998 So it's a need to have a tow truck to push them back onto the taxiway. 54 00:03:53,041 --> 00:03:56,919 But as Flight 6316 is being pushed back... 55 00:03:59,714 --> 00:04:01,174 Uh, something's not right. 56 00:04:01,174 --> 00:04:04,052 ...the Captain notices something amiss. 57 00:04:04,052 --> 00:04:06,262 Why is that brake temperature light on? 58 00:04:06,763 --> 00:04:09,599 It seems this brake isn't released. 59 00:04:10,224 --> 00:04:12,060 The captain noticed there is a caution 60 00:04:12,060 --> 00:04:16,355 that shows there is a high temperature on one of the brakes. 61 00:04:16,355 --> 00:04:18,900 It doesn't mean this brake is failing. 62 00:04:18,900 --> 00:04:21,861 It just means this brake is hotter than the others. 63 00:04:21,861 --> 00:04:24,947 Yeah, when we landed that brake temp showed up. 64 00:04:27,075 --> 00:04:29,202 In some rare conditions, the hot brake 65 00:04:29,202 --> 00:04:30,787 can lead to fire in flight. 66 00:04:30,787 --> 00:04:34,540 But at this point, the hot brake is not a serious issue. 67 00:04:34,540 --> 00:04:36,709 You just keep an eye on it. 68 00:04:38,294 --> 00:04:39,295 It's dropping down now. 69 00:04:45,134 --> 00:04:47,095 I wonder what's gonna happen when we take off. 70 00:04:52,433 --> 00:04:56,729 Captain, cleared to start engines 3-1-2. 71 00:04:56,729 --> 00:04:59,148 Roger, starting number three. 72 00:05:01,484 --> 00:05:06,239 The pilots are flying a McDonnell Douglas M-D-11-F. 73 00:05:06,989 --> 00:05:11,619 The MD-11 is a large, wide-body aircraft. 74 00:05:11,619 --> 00:05:13,830 This is a very high-performance airplane. 75 00:05:13,830 --> 00:05:16,708 And once you understand the MD-11, 76 00:05:16,708 --> 00:05:19,502 it is a very pleasurable airplane to fly, 77 00:05:19,502 --> 00:05:24,924 {\an8}but it does require the pilots to be on top of their game. 78 00:05:26,175 --> 00:05:29,887 Hongqiao tower, Korean Air 6316 request taxi. 79 00:05:30,388 --> 00:05:36,686 Korean Air 6316 taxi via kilo-seven tango-zero for runway 1-8. 80 00:05:37,979 --> 00:05:42,191 The aircraft begins taxiing to runway 1-8. 81 00:05:44,569 --> 00:05:48,114 - Right side clear? - Right side clear. 82 00:05:48,614 --> 00:05:50,366 Left side clear. 83 00:05:59,751 --> 00:06:02,337 So many airlines at this airport. 84 00:06:05,673 --> 00:06:09,344 It's 77. It's normal now. 85 00:06:10,386 --> 00:06:13,681 The elevated brake temperature has returned to normal. 86 00:06:13,681 --> 00:06:17,560 Korean Air 6316 clear for takeoff. 87 00:06:18,352 --> 00:06:22,815 Clear for take off 6316. Confirming, we're clear for takeoff. 88 00:06:33,910 --> 00:06:35,411 Check thrust. 89 00:06:35,411 --> 00:06:38,831 Thrust is set. Eighty knots... 90 00:06:41,417 --> 00:06:43,086 V1... 91 00:06:45,046 --> 00:06:47,465 Rotate. 92 00:06:48,424 --> 00:06:53,054 Just after 4pm, they lift off from Shanghai. 93 00:06:55,431 --> 00:06:57,100 Positive climb. 94 00:06:57,558 --> 00:06:59,018 Gear up. 95 00:07:08,820 --> 00:07:13,116 The flight from Shanghai to Seoul is expected to take two hours. 96 00:07:15,868 --> 00:07:18,621 Shortly after takeoff, the controller provides 97 00:07:18,621 --> 00:07:21,165 the pilots with their climb-out instructions. 98 00:07:21,165 --> 00:07:25,086 Korean Air, 6316, now turn left direct to November 99 00:07:25,086 --> 00:07:28,715 Hotel Whiskey, then climb and maintain 1,500 metres. 100 00:07:28,715 --> 00:07:35,972 The M-D-11 is to continue climbing and turn left to intercept N H W. 101 00:07:36,639 --> 00:07:39,642 N-H-W, or November Hotel Whiskey, is 102 00:07:39,642 --> 00:07:43,312 a ground-based navigation beacon that assists pilots 103 00:07:43,312 --> 00:07:45,898 in guiding their plane through the skies. 104 00:07:47,567 --> 00:07:49,610 Okay, direct November Hotel Whiskey. 105 00:07:49,610 --> 00:07:51,070 And say again altitude? 106 00:07:52,488 --> 00:07:55,074 Reconfirming the altitude instruction is smart. 107 00:07:55,074 --> 00:07:58,661 Every aircraft have their assigned route 108 00:07:58,661 --> 00:08:01,664 or assigned altitude by the ATC. 109 00:08:01,664 --> 00:08:04,751 So that is very important to hold this altitude 110 00:08:04,751 --> 00:08:07,170 to avoid the conflicts with others. 111 00:08:08,046 --> 00:08:11,007 But as the pilots confirm their instructions, 112 00:08:11,007 --> 00:08:15,428 the controller notices the plane has yet to turn towards 113 00:08:15,428 --> 00:08:17,680 the N-H-W navigation fix. 114 00:08:18,389 --> 00:08:22,894 Flight 6316 turn left direct to November Hotel Whiskey, 115 00:08:22,894 --> 00:08:26,189 then climb and maintain 1,500 metres. 116 00:08:27,732 --> 00:08:30,234 The controller can see on the radar scope 117 00:08:30,234 --> 00:08:32,361 that the aircraft is not turning left. 118 00:08:32,361 --> 00:08:36,449 And so is reminding the crew that they need to turn left 119 00:08:36,449 --> 00:08:38,451 by reissuing the clearance. 120 00:08:43,539 --> 00:08:46,459 But as the controller repeats his instructions... 121 00:08:47,335 --> 00:08:49,045 I don't see NHW. 122 00:08:49,045 --> 00:08:51,756 ...the navigation fix does not appear 123 00:08:51,756 --> 00:08:54,050 on the Captain's display screen. 124 00:08:55,676 --> 00:08:57,553 Where is it? 125 00:08:57,553 --> 00:09:02,308 Uh, here. Keep turning left. 126 00:09:02,308 --> 00:09:03,476 Keep turning. 127 00:09:03,851 --> 00:09:06,479 - Keep turning? - Yes, keep turning more. 128 00:09:07,689 --> 00:09:10,233 As the pilots continue their turn, 129 00:09:10,233 --> 00:09:13,695 the controller realizes the plane isn't climbing. 130 00:09:14,320 --> 00:09:19,158 Korean Air 6316, climb and maintain 1,500 metres. 131 00:09:19,909 --> 00:09:21,077 Are they asking us to-- 132 00:09:21,077 --> 00:09:22,829 Yes, they're... they're telling us to climb. 133 00:09:27,208 --> 00:09:28,418 The aircraft hasn't even reached 134 00:09:28,418 --> 00:09:31,254 the initial altitude that they were cleared to. 135 00:09:31,254 --> 00:09:34,257 So this is a way to remind the crew, 136 00:09:34,257 --> 00:09:37,009 we need to get moving, we need to climb. 137 00:09:38,594 --> 00:09:43,016 Just as Flight 6316 nears its assigned altitude... 138 00:09:45,226 --> 00:09:47,562 ...it disappears from the radar. 139 00:09:56,404 --> 00:09:58,906 The plane is diving uncontrollably towards 140 00:09:58,906 --> 00:10:02,201 the ground, too fast to be picked up by radar. 141 00:10:02,201 --> 00:10:05,580 The controller is unaware of its descent. 142 00:10:06,330 --> 00:10:09,459 Korean Air 6316, do you read? 143 00:10:11,627 --> 00:10:13,379 Wait, wait... pitch 144 00:10:16,758 --> 00:10:19,552 Korean Air 6316, radio check. 145 00:10:24,599 --> 00:10:29,520 Korean Air Flight 6316 bursts throh the clouds above Shanghai... 146 00:10:29,520 --> 00:10:30,480 Terrain. Terrain. 147 00:10:30,480 --> 00:10:32,148 Nose up. Nose up. Nose up. 148 00:10:32,148 --> 00:10:35,026 Pull up. Pull up. 149 00:10:38,696 --> 00:10:41,908 ...and slams into the ground seven miles 150 00:10:41,908 --> 00:10:43,409 from the airport... 151 00:10:44,577 --> 00:10:47,997 ...less than two-and-a-half minutes after takeoff. 152 00:10:49,374 --> 00:10:51,876 At the speed they hit the ground, 153 00:10:51,876 --> 00:10:56,005 {\an8}the impact was so severe that it registered 154 00:10:56,005 --> 00:10:58,716 {\an8}the equivalent of a 1.6 earthquake. 155 00:11:01,010 --> 00:11:03,429 The aircraft crashes in Xinzhuang 156 00:11:03,429 --> 00:11:06,474 on the outskirts of the town's residential area. 157 00:11:09,018 --> 00:11:14,023 The accident claims the lives of both pilots and the Flight Technician. 158 00:11:16,067 --> 00:11:20,196 Five civilians are killed, 40 more are injured. 159 00:11:27,036 --> 00:11:31,624 The investigation into the crash is handled jointly by the three countries involved. 160 00:11:31,624 --> 00:11:35,878 Representatives from the Korean Civilian Aviation Bureau 161 00:11:35,878 --> 00:11:38,339 are onsite on behalf of the airline. 162 00:11:39,382 --> 00:11:41,884 With the crash occurring on Chinese soil, 163 00:11:41,884 --> 00:11:46,723 the investigation is led by the Civil Aviation Administration of China. 164 00:11:49,600 --> 00:11:51,728 And as the plane is manufactured in the U-S, 165 00:11:51,728 --> 00:11:57,316 an American investigator from the National Transportation Safety Board joins the team. 166 00:11:57,316 --> 00:11:58,735 What'd you find? 167 00:11:58,735 --> 00:12:03,364 The debris trail runs nearly two kilometres. Fan pattern. 168 00:12:05,658 --> 00:12:10,455 {\an8}Typically, on impact, as the airplane hits the ground, 169 00:12:10,455 --> 00:12:14,000 {\an8}all of a sudden pieces will start coming apart. 170 00:12:14,334 --> 00:12:17,253 The biggest pieces will keep going straight. 171 00:12:17,253 --> 00:12:21,090 The other pieces will start fanning out. They'll spread. 172 00:12:21,758 --> 00:12:24,844 They had to impact at a relatively shallow angle 173 00:12:24,844 --> 00:12:26,220 to make that pattern. 174 00:12:27,430 --> 00:12:31,184 But as investigators continue to analyze the crash site, 175 00:12:31,184 --> 00:12:34,187 they learn that critical evidence has been destroyed. 176 00:12:35,313 --> 00:12:37,523 Not much left of the Flight Data Recorder. 177 00:12:41,652 --> 00:12:44,238 {\an8}One of the major tools in a modern aircraft 178 00:12:44,238 --> 00:12:46,991 {\an8}accident investigation is the flight data recorder. 179 00:12:46,991 --> 00:12:51,037 More modern ones can record thousands of parametres: 180 00:12:51,037 --> 00:12:54,123 angle of attack, airspeed, engine parametres. 181 00:12:55,166 --> 00:13:00,797 The lack of a flight data recorder during an investigation is a major blow. 182 00:13:08,596 --> 00:13:10,181 Police say some of the cargo has been stolen 183 00:13:10,181 --> 00:13:11,474 from the crash site. 184 00:13:12,683 --> 00:13:15,061 In the chaos, some of the local residents 185 00:13:15,061 --> 00:13:17,271 decided to help themselves to some of the cargo. 186 00:13:17,271 --> 00:13:21,776 This creates a situation where investigators might not find 187 00:13:21,776 --> 00:13:25,530 critical parts that they need to solve the accident. 188 00:13:25,530 --> 00:13:28,408 Has anyone found the Cockpit Voice Recorder? 189 00:13:31,411 --> 00:13:33,454 Hopefully that wasn't stolen too. 190 00:13:36,457 --> 00:13:38,876 If you don't have a flight data recorder and you don't have 191 00:13:38,876 --> 00:13:43,256 a cockpit voice recorder, you really have to go back to the basics 192 00:13:43,256 --> 00:13:45,174 to try to figure out what happened. 193 00:13:46,008 --> 00:13:49,762 Investigators start by examining "impact scars" 194 00:13:49,762 --> 00:13:52,724 left by the engines to determine at what attitude 195 00:13:52,724 --> 00:13:54,684 the plane struck the ground. 196 00:13:55,560 --> 00:13:58,813 The ground slopes 30 degrees down from the horizontal. 197 00:13:59,647 --> 00:14:02,108 Slope is the same for the other ground scar. 198 00:14:02,108 --> 00:14:03,693 And wings were level. 199 00:14:05,737 --> 00:14:08,781 The aircraft engines are very heavy. 200 00:14:08,781 --> 00:14:10,450 They'll make their own craters. 201 00:14:10,450 --> 00:14:14,328 So you look at the angle the engines are in, 202 00:14:14,328 --> 00:14:18,708 that gives you a very good idea of the pitch angle at impact. 203 00:14:18,708 --> 00:14:21,878 Because those parts are basically going to try 204 00:14:21,878 --> 00:14:24,380 to just bore a hole into the dirt. 205 00:14:24,380 --> 00:14:27,133 So the aircraft takes off. 206 00:14:27,133 --> 00:14:32,930 Roughly three minutes later, it crashes in a dive 30 degrees nose down, with wings level. 207 00:14:33,389 --> 00:14:35,308 So what caused the dive? 208 00:14:38,019 --> 00:14:39,645 The ground information tells you 209 00:14:39,645 --> 00:14:40,938 how the airplane went down. 210 00:14:40,938 --> 00:14:43,566 We don't know why it went down. 211 00:14:43,566 --> 00:14:46,235 And that takes a lot more effort. 212 00:14:47,236 --> 00:14:48,738 We need to test for explosives. 213 00:14:48,738 --> 00:14:50,782 Get at least a dozen specimens from the wreckage 214 00:14:50,782 --> 00:14:53,576 and send those samples to the lab for testing. 215 00:14:53,576 --> 00:14:59,665 Chinese authorities wonder if an act of terrorism could have caused the accident. 216 00:14:59,665 --> 00:15:02,668 In any investigation, anything could have happened. 217 00:15:02,668 --> 00:15:05,755 And one of those events could have been sabotage or a bomb. 218 00:15:05,755 --> 00:15:10,051 So it's important in investigations to rule out 219 00:15:10,051 --> 00:15:12,261 something like that, as soon as possible. 220 00:15:14,305 --> 00:15:17,266 As police look for evidence of explosives, 221 00:15:17,266 --> 00:15:20,770 investigators interview the Air Traffic Controller. 222 00:15:21,854 --> 00:15:27,026 Anyone who talked to the crew is a witness to the investigation. 223 00:15:27,026 --> 00:15:29,862 And the controller is the last person to talk to the crew. 224 00:15:29,862 --> 00:15:33,783 So it was very important to get his impressions, what he did, 225 00:15:33,783 --> 00:15:39,539 what he's hearing back from the pilots and understand what was happening that night. 226 00:15:40,707 --> 00:15:43,626 To start, what stood out to you about the flight? 227 00:15:43,626 --> 00:15:45,628 Takeoff seemed normal. 228 00:15:45,628 --> 00:15:48,631 But afterwards, the pilots struggled to maintain the flight plan. 229 00:15:50,466 --> 00:15:53,594 Turn left direct to November Hotel Whiskey. 230 00:15:53,594 --> 00:15:56,347 Then climb and maintain 1,500 metres. 231 00:15:57,432 --> 00:15:59,600 They eventually made their turn. But I had to remind them. 232 00:15:59,600 --> 00:16:01,144 After that? 233 00:16:01,144 --> 00:16:04,063 As they corrected their turn, I noticed they were still too low. 234 00:16:04,063 --> 00:16:06,274 So I told them to climb. 235 00:16:07,567 --> 00:16:12,196 Korean Air 6316, climb and maintain 1,500 metres. 236 00:16:12,739 --> 00:16:15,742 I had to remind them a second time, before they started to climb. 237 00:16:18,286 --> 00:16:19,996 I thought they were off safely. 238 00:16:19,996 --> 00:16:23,416 The next thing I knew, the plane disappeared from radar. 239 00:16:25,793 --> 00:16:30,465 The air traffic controller sees the aircraft climbing. 240 00:16:30,465 --> 00:16:32,383 Everything looks normal and fine, 241 00:16:32,383 --> 00:16:35,303 and then all of a sudden, things go very wrong. 242 00:16:35,303 --> 00:16:38,765 Korean Air 6316, do you read? 243 00:16:40,058 --> 00:16:42,351 Korean Air 6316, radio check. 244 00:16:47,231 --> 00:16:49,442 - Is that the radar data? - Yes. 245 00:16:50,860 --> 00:16:53,029 It looks like your communication was by the book. 246 00:16:53,029 --> 00:16:54,530 Thank you. 247 00:16:55,865 --> 00:16:58,743 Looking at the radar recordings is very important, 248 00:16:58,743 --> 00:17:03,539 especially if you haven't looked at the cockpit voice recorder or the FDR. 249 00:17:03,539 --> 00:17:06,876 This gives you an initial framework to work with. 250 00:17:08,044 --> 00:17:11,381 Can the radar data provide any clues? 251 00:17:13,633 --> 00:17:17,804 The plane climbs to 1,371 metres or 4,500 feet. 252 00:17:18,429 --> 00:17:21,599 Roughly 16 seconds later, it impacts the ground. 253 00:17:22,392 --> 00:17:27,313 That's a descent rate of roughly... 254 00:17:29,232 --> 00:17:31,693 ...17,000 feet per minute. 255 00:17:34,904 --> 00:17:38,783 We have a saying in aviation called 'the minute to die rule', 256 00:17:38,783 --> 00:17:43,204 which means that if your rate of descent in feet per minute 257 00:17:43,204 --> 00:17:47,417 is greater than your altitude, that's a dangerous situation. 258 00:17:47,417 --> 00:17:50,503 Flight 6316's rate of descent 259 00:17:50,503 --> 00:17:53,965 was more than three times greater than their altitude. 260 00:17:53,965 --> 00:17:55,341 Pull up. 261 00:17:55,341 --> 00:17:58,177 It's virtually impossible to recover the aircraft. 262 00:17:59,637 --> 00:18:04,058 What would cause the plane to descend at such an incredible speed? 263 00:18:04,058 --> 00:18:06,686 Maybe there was a problem with the aircraft. 264 00:18:07,478 --> 00:18:09,147 I'll pull the maintenance records. 265 00:18:10,398 --> 00:18:12,942 During the initial stages of the investigation, 266 00:18:12,942 --> 00:18:16,821 the investigators will look at all of the maintenance records of the aircraft. 267 00:18:16,821 --> 00:18:20,867 Any write-ups of issues on handling, 268 00:18:20,867 --> 00:18:25,163 delayed maintenance for some reason... 269 00:18:25,163 --> 00:18:30,376 anything at all that would give a clue to what could have happened here. 270 00:18:35,840 --> 00:18:37,050 Here's something. 271 00:18:37,050 --> 00:18:39,510 Investigators examine maintenance records 272 00:18:39,510 --> 00:18:41,512 of Korean Air Flight 6316, 273 00:18:41,512 --> 00:18:45,350 looking for clues to explain why a modern jetliner 274 00:18:45,350 --> 00:18:47,977 plunged from the sky so soon after takeoff. 275 00:18:47,977 --> 00:18:53,483 On May 25, 1996, the aircraft experienced a tail strike at LAX. 276 00:18:56,611 --> 00:19:00,406 The incident required a repair that took 63 days to complete? 277 00:19:02,617 --> 00:19:05,787 That was an interesting finding because 278 00:19:05,787 --> 00:19:08,164 {\an8}if the repairs to the aircraft from the tail strike 279 00:19:08,164 --> 00:19:12,126 {\an8}are not done properly, it can cause that area to detach 280 00:19:12,126 --> 00:19:16,589 in flight and in the process damage the pitch controls of the airplane. 281 00:19:16,589 --> 00:19:19,092 And we've seen that before. 282 00:19:19,592 --> 00:19:23,971 In 1978, a Japan Airlines Boeing 747 283 00:19:23,971 --> 00:19:27,016 suffered a tail strike while landing at Osaka. 284 00:19:27,016 --> 00:19:30,603 A faulty repair led to an explosive decompression 285 00:19:30,603 --> 00:19:35,942 seven years later, tearing off the tail and killing 520 people. 286 00:19:39,696 --> 00:19:43,491 If that's what happened here, that could explain everything. 287 00:19:44,158 --> 00:19:49,038 Did poor maintenance cause the plane's tail to break apart mid-flight? 288 00:19:59,924 --> 00:20:02,051 Well, here's the vertical stabilizer. 289 00:20:02,051 --> 00:20:07,807 Investigators find pieces of Korean Air Flight 6316's tail section 290 00:20:07,807 --> 00:20:09,142 in the wreckage. 291 00:20:10,017 --> 00:20:13,563 With all the pieces of the tail this close to the main crash site, 292 00:20:13,563 --> 00:20:15,898 it didn't separate in-flight. 293 00:20:16,399 --> 00:20:18,192 So the repair was done correctly. 294 00:20:18,901 --> 00:20:21,904 They conclude a tail strike did not cause 295 00:20:21,904 --> 00:20:25,408 any part of the MD-11's tail to detach from the plane. 296 00:20:25,992 --> 00:20:27,994 Maybe the dive was caused by a failure 297 00:20:27,994 --> 00:20:30,163 in one of the plane's control surfaces. 298 00:20:30,163 --> 00:20:32,081 Like the horizontal stabilizer. 299 00:20:35,668 --> 00:20:38,588 The horizontal stabilizer is the small wing 300 00:20:38,588 --> 00:20:41,632 on the tail that controls the pitch of the aircraft. 301 00:20:43,551 --> 00:20:45,845 Maybe the jackscrew jammed? 302 00:20:49,098 --> 00:20:52,602 When commanded, a jackscrew in the tail rotates, 303 00:20:52,602 --> 00:20:56,481 moving the horizontal stabilizer up or down. 304 00:20:57,690 --> 00:21:00,860 If the jackscrew has jammed in a nose down position, 305 00:21:00,860 --> 00:21:03,821 now the airplane would suddenly pitch over 306 00:21:03,821 --> 00:21:07,283 and the flight crew would be fighting to try 307 00:21:07,283 --> 00:21:08,701 to get the nose up. 308 00:21:08,701 --> 00:21:11,662 - Pitch. - O-oh-okay. Okay. 309 00:21:12,580 --> 00:21:14,540 But they would have a lot of forces 310 00:21:14,540 --> 00:21:19,629 on the control column, trying to fight the aircraft from pitching down towards the earth. 311 00:21:23,675 --> 00:21:26,636 Was the horizontal stabilizer jammed 312 00:21:26,636 --> 00:21:30,556 in a nose-down position, causing the plane to plummet? 313 00:21:33,267 --> 00:21:34,894 Well, the jackscrew isn't jammed. 314 00:21:34,894 --> 00:21:37,146 So the stabilizer was working as intended. 315 00:21:37,146 --> 00:21:39,148 And what position is it in? 316 00:21:43,695 --> 00:21:45,738 10.25 inches. 317 00:21:45,738 --> 00:21:51,202 So it was set to .65 degrees, nose-up. 318 00:21:53,871 --> 00:21:57,542 {\an8}The pilots were fighting against the dive... 319 00:21:58,918 --> 00:22:00,753 Nose up, nose up, nose up. 320 00:22:00,753 --> 00:22:03,881 ...trimming the horizontal stabilizer 321 00:22:03,881 --> 00:22:06,592 nose up while pulling back on the controls 322 00:22:06,592 --> 00:22:08,594 to try to arrest the descent. 323 00:22:08,594 --> 00:22:10,888 Terrain, terrain. 324 00:22:23,192 --> 00:22:25,611 Chemical analysis report is in from the wreckage. 325 00:22:25,611 --> 00:22:27,488 No evidence of explosives. 326 00:22:27,488 --> 00:22:30,616 I'll start typing this up for the press. 327 00:22:30,616 --> 00:22:34,245 We need to reassure the public it's safe to fly in China. 328 00:22:34,245 --> 00:22:35,621 Sounds good. 329 00:22:38,166 --> 00:22:41,252 The Civil Aviation Administration of China 330 00:22:41,252 --> 00:22:45,757 along with its U-S and Korean counterparts release a bulletin 331 00:22:45,757 --> 00:22:47,884 almost two weeks after the incident. 332 00:22:48,259 --> 00:22:51,304 The Chinese investigation want to make two things clear. 333 00:22:51,304 --> 00:22:52,764 {\an8}One, it's not a bomb. 334 00:22:52,764 --> 00:22:56,559 {\an8}Two, it's not a fault from the Chinese ATC controller. 335 00:22:56,976 --> 00:23:01,773 With terrorism, air traffic control and poor maintenance discounted, 336 00:23:01,773 --> 00:23:05,151 investigators now focus their attention to the pilots. 337 00:23:05,651 --> 00:23:06,819 Let's start with the Captain. 338 00:23:07,361 --> 00:23:10,948 In all accidents, one of the tasks 339 00:23:10,948 --> 00:23:14,410 is investigating the background of the pilots 340 00:23:14,410 --> 00:23:16,954 to ensure that there's no issues. 341 00:23:16,954 --> 00:23:19,832 V-1. Rotate. 342 00:23:19,832 --> 00:23:21,167 Rotate. 343 00:23:21,167 --> 00:23:24,045 Training can make a very big difference. 344 00:23:24,045 --> 00:23:26,172 And also, things going on in their personal life. 345 00:23:26,172 --> 00:23:29,175 We want to make sure that the person wasn't under 346 00:23:29,175 --> 00:23:32,512 any particular stressors that could cause distractions 347 00:23:32,512 --> 00:23:36,015 and inhibit their performance in any way. 348 00:23:36,849 --> 00:23:38,601 Captain Hong was quite seasoned. 349 00:23:39,602 --> 00:23:44,232 Almost 13,000 flight hours, with nearly 5,000 on the MD-11 alone. 350 00:23:45,149 --> 00:23:48,111 No psychological burdens and a perfect safety record. 351 00:23:48,611 --> 00:23:53,783 Yeah. First Officer Park, over 1,800 hours, majority on the MD-11. 352 00:23:53,783 --> 00:23:58,204 No psychological burdens and also a perfect safety record. 353 00:23:58,788 --> 00:24:00,623 - Two model pilots. - Yeah. 354 00:24:05,920 --> 00:24:09,298 Yes. Is it intact? 355 00:24:10,758 --> 00:24:13,052 They found the Cockpit Voice Recorder. 356 00:24:15,513 --> 00:24:19,809 After the accident, there was very heavy rain in the Shanghai area. 357 00:24:19,809 --> 00:24:23,730 So they pumped out some water from some of the ponds 358 00:24:23,730 --> 00:24:27,900 that were left and they found the CVR. 359 00:24:27,900 --> 00:24:31,237 Memory is safe. Full data recovery. 360 00:24:32,947 --> 00:24:35,199 Excellent work. And thank you. 361 00:24:37,326 --> 00:24:39,328 They're going to get the transcripts ready for us. 362 00:24:39,328 --> 00:24:43,082 At this point in the investigation, we're wondering what caused 363 00:24:43,082 --> 00:24:48,921 a mechanically sound airplane piloted by two well-trained, 364 00:24:48,921 --> 00:24:51,841 experienced pilots, to suddenly dive into the ground. 365 00:24:51,841 --> 00:24:54,260 And that becomes the mystery. 366 00:25:02,727 --> 00:25:05,188 Okay. Let's start with an aerodynamic stall 367 00:25:05,188 --> 00:25:07,607 from 1,371 metres. 368 00:25:11,903 --> 00:25:14,906 Using a Boeing simulator in California... 369 00:25:14,906 --> 00:25:18,034 We'll see what rate of descent we get. 370 00:25:19,160 --> 00:25:22,789 ...investigators combine radar data with evidence 371 00:25:22,789 --> 00:25:27,835 from the wreckage of Korean Air Flight 6316 to determine 372 00:25:27,835 --> 00:25:30,213 why the plane plummeted to the ground. 373 00:25:32,173 --> 00:25:34,801 {\an8}In the simulator, the investigators accomplished 374 00:25:34,801 --> 00:25:38,221 {\an8}over a hundred different scenarios. Trial and error. 375 00:25:38,221 --> 00:25:40,640 How do we match the data points? 376 00:25:42,558 --> 00:25:44,185 Pull up. 377 00:25:44,560 --> 00:25:48,731 Rate of descent was 3,314 feet per minute, 378 00:25:48,731 --> 00:25:52,985 not even close to 17,000. It couldn't have been a stall. 379 00:25:54,404 --> 00:25:58,116 And so, they take all this information 380 00:25:58,116 --> 00:26:03,413 and in the simulator try to determine what's the best fit for the data. 381 00:26:03,413 --> 00:26:05,581 And you start eliminating things. 382 00:26:05,581 --> 00:26:07,917 Let's try Out of Control Elevators. 383 00:26:07,917 --> 00:26:10,003 The accident plane impacted nose down 384 00:26:10,003 --> 00:26:12,130 at an estimated 20 to 40 degrees. 385 00:26:25,393 --> 00:26:26,853 The pitch is way too sharp. 386 00:26:26,853 --> 00:26:29,397 Let's try to pull up anyway for accuracy. 387 00:26:31,274 --> 00:26:32,817 Through all the simulator runs they did... 388 00:26:32,817 --> 00:26:36,279 Pull up. 389 00:26:36,779 --> 00:26:38,239 86 degrees. 390 00:26:38,239 --> 00:26:41,033 Okay, it was not Out of Control Elevators either. 391 00:26:41,033 --> 00:26:44,454 ...they found that you could not match 392 00:26:44,454 --> 00:26:48,041 the rate of descent and the profile you needed to match 393 00:26:48,041 --> 00:26:52,295 the data with an aerodynamic stall or a mechanical failure. 394 00:26:57,925 --> 00:27:00,970 Try intentionally pushing the plane into a dive... 395 00:27:10,730 --> 00:27:12,315 Push your nose down. 396 00:27:12,315 --> 00:27:13,983 Let vertical speed increase. 397 00:27:13,983 --> 00:27:15,902 Then trim the horizontal stabilizer up, 398 00:27:15,902 --> 00:27:18,279 then try to pull out of it. 399 00:27:25,036 --> 00:27:29,832 Start the dive in three, two, one, go. 400 00:27:35,546 --> 00:27:39,509 Stabilizer in motion. Pull up. 401 00:27:39,509 --> 00:27:45,264 Only one simulation precisely replicates the data from Flight 6316. 402 00:27:45,848 --> 00:27:47,975 Dive time, 18 seconds. 403 00:27:47,975 --> 00:27:50,436 25 degrees nose down. 404 00:27:50,436 --> 00:27:52,021 Maxed out rate of descent. 405 00:27:52,021 --> 00:27:54,357 That's the closest we've been yet. 406 00:27:54,357 --> 00:27:56,275 Investigators conclude that the plane 407 00:27:56,275 --> 00:27:59,195 must have been put into a nose dive intentionally. 408 00:27:59,195 --> 00:28:03,282 The data showed that the upset was caused by a pilot input. 409 00:28:03,282 --> 00:28:08,246 And so now the focus becomes on, why would the pilot do this? 410 00:28:09,247 --> 00:28:11,874 Knowing that the crash of Flight 6316 411 00:28:11,874 --> 00:28:14,585 could have resulted only from deliberate pilot input, 412 00:28:14,585 --> 00:28:18,715 investigators listen to the CVR to determine why the pilots 413 00:28:18,715 --> 00:28:21,384 commanded the airplane into a steep dive. 414 00:28:21,801 --> 00:28:24,387 Okay. Let's have a listen. 415 00:28:25,847 --> 00:28:28,933 Captain, can you release the parking brake? 416 00:28:28,933 --> 00:28:31,853 Okay, brake released. 417 00:28:33,938 --> 00:28:35,815 Wow. Something's not right. 418 00:28:37,066 --> 00:28:39,527 Why is that brake temperature light on? 419 00:28:40,987 --> 00:28:45,283 Is the high brake temperature somehow connected to the nosedive? 420 00:28:46,367 --> 00:28:49,495 Yeah, when we landed, that brake temp showed up. 421 00:28:49,871 --> 00:28:51,414 But soon after... 422 00:28:51,414 --> 00:28:53,374 It's dropping down now. 423 00:28:54,792 --> 00:28:56,919 So the brake was a non-factor. 424 00:28:58,629 --> 00:29:01,090 Agreed. Let's keep going. 425 00:29:03,092 --> 00:29:05,928 Flight 6316, copy ATC clearance. 426 00:29:06,846 --> 00:29:09,223 Go ahead, Korean Air 6316. 427 00:29:09,223 --> 00:29:12,435 Korean Air 6316, after departure turn left 428 00:29:12,435 --> 00:29:14,771 direct to November Hotel Whiskey. 429 00:29:14,771 --> 00:29:16,981 Initially climb and maintain 900 metres. 430 00:29:16,981 --> 00:29:18,524 Read back please. 431 00:29:18,524 --> 00:29:21,819 Okay, sir, initially maintain 900 metres, then after takeoff, 432 00:29:21,819 --> 00:29:25,031 left turn direct to November Hotel Whiskey. Is that correct? 433 00:29:25,031 --> 00:29:26,532 That's affirmative. 434 00:29:27,200 --> 00:29:30,620 - Did he say 900 metres? - Yeah, 900 feet. 435 00:29:34,707 --> 00:29:35,875 Did you catch that? 436 00:29:35,875 --> 00:29:38,252 After the controller read the altitude clearance. 437 00:29:38,252 --> 00:29:41,798 Investigators hear that there's some confusion 438 00:29:41,798 --> 00:29:43,466 about altitude measurements. 439 00:29:44,509 --> 00:29:46,803 Yeah, why are they using metric at all? 440 00:29:46,803 --> 00:29:48,721 Imperial is airspace standard. 441 00:29:48,721 --> 00:29:51,140 Not in China. 442 00:29:52,684 --> 00:29:57,980 {\an8}Most of this world, including South Korea, measure altitude in feet. 443 00:29:57,980 --> 00:30:04,946 The Chinese aviation industry is based on the old Soviet Union aviation industry. 444 00:30:05,530 --> 00:30:12,662 The USSR used the Metric system, so today China still uses the Metric system. 445 00:30:14,163 --> 00:30:17,834 Okay. But I imagine the Captain will sort that out 446 00:30:17,834 --> 00:30:19,002 in the takeoff briefing. 447 00:30:19,002 --> 00:30:21,003 Let's find out. 448 00:30:22,088 --> 00:30:23,798 Korean Air 6316... 449 00:30:23,798 --> 00:30:25,091 ...clear for takeoff. 450 00:30:25,091 --> 00:30:27,343 Clear for take off 6316. 451 00:30:27,343 --> 00:30:29,637 Confirming, we're clear for takeoff. 452 00:30:31,431 --> 00:30:32,932 Wait... 453 00:30:32,932 --> 00:30:36,019 Did the Captain skip his takeoff briefing? 454 00:30:36,019 --> 00:30:38,521 I'm not seeing one in here. 455 00:30:39,772 --> 00:30:43,025 A takeoff briefing is a way to create 456 00:30:43,025 --> 00:30:46,612 {\an8}what we call "a shared mental model," where both pilots 457 00:30:46,612 --> 00:30:47,989 {\an8}are on the same page. 458 00:30:47,989 --> 00:30:50,533 Otherwise you're simply not prepared for the flight. 459 00:30:51,200 --> 00:30:56,289 The briefing would have also noted that Shanghai uses metric altitudes. 460 00:30:57,165 --> 00:30:58,875 So did skipping the briefing 461 00:30:58,875 --> 00:31:01,294 somehow play a role in the nose dive? 462 00:31:08,926 --> 00:31:11,220 Investigators revisit the CVR 463 00:31:11,220 --> 00:31:13,681 searching for evidence that the omission 464 00:31:13,681 --> 00:31:17,977 of a critical briefing contributed to the crash of Flight 6316. 465 00:31:17,977 --> 00:31:20,438 Let's start with the initial climb. 466 00:31:22,857 --> 00:31:26,194 Turn left direct to November Hotel Whiskey, 467 00:31:26,194 --> 00:31:29,030 then climb and maintain 1,500 metres. 468 00:31:29,530 --> 00:31:32,158 The team hears the controller giving the pilots 469 00:31:32,158 --> 00:31:34,619 their climb out instructions... 470 00:31:34,619 --> 00:31:36,037 I don't see NHW. 471 00:31:38,373 --> 00:31:39,123 Where is it? 472 00:31:40,083 --> 00:31:43,753 ...but the Captain can't find the navigation beacon on his display. 473 00:31:44,295 --> 00:31:48,049 It sounds like an issue with the Captain's NAV display. 474 00:31:49,801 --> 00:31:52,845 Uh... here. Keep turning left. 475 00:31:53,346 --> 00:31:55,139 The recording suggests the First Officer's 476 00:31:55,139 --> 00:31:57,975 navigation display was functioning properly. 477 00:31:57,975 --> 00:32:01,187 - Keep turning - Keep turning? 478 00:32:01,187 --> 00:32:02,563 Yes, keep turning more. 479 00:32:03,940 --> 00:32:07,110 Damn. Why isn't NHW showing? 480 00:32:07,568 --> 00:32:11,572 The CVR portrays a captain who appears confused. 481 00:32:14,409 --> 00:32:17,286 I bet he zoomed in too far on the NAV display. 482 00:32:17,286 --> 00:32:19,080 That's why he can't see the beacon. 483 00:32:19,080 --> 00:32:22,417 {\an8}Had the pilot reached up and changed the range on his display, 484 00:32:22,417 --> 00:32:24,544 {\an8}he would have had that available to him. 485 00:32:24,544 --> 00:32:27,672 That would explain why it took them so long to turn left. 486 00:32:29,048 --> 00:32:32,343 Had they done the takeoff briefing, they could have caught the issue. 487 00:32:33,761 --> 00:32:37,515 Had they discussed completely in the preflight briefing, 488 00:32:37,515 --> 00:32:41,394 here's where we're going, and cross-checked their displays 489 00:32:41,394 --> 00:32:44,439 that would have been caught. And it wasn't. 490 00:32:45,231 --> 00:32:47,108 It still doesn't explain the dive, though. 491 00:32:49,944 --> 00:32:51,821 Korean Air 6316... 492 00:32:51,821 --> 00:32:54,615 climb and maintain 1,500 metres. 493 00:32:54,615 --> 00:32:56,200 Are they asking us to-- 494 00:32:56,200 --> 00:32:58,536 Yes, they're telling us to climb. 495 00:33:01,789 --> 00:33:04,250 It seems like they're so preoccupied getting the plane 496 00:33:04,250 --> 00:33:07,462 to turn left they forgot to climb. 497 00:33:08,338 --> 00:33:11,466 Especially since the controller told them twice. 498 00:33:15,762 --> 00:33:18,389 Then investigators hear a warning telling the pilots 499 00:33:18,389 --> 00:33:20,767 that they're approaching their target altitude... 500 00:33:20,767 --> 00:33:22,602 Altitude. 501 00:33:23,019 --> 00:33:24,562 Uh, pitch, sir. 502 00:33:25,146 --> 00:33:28,149 ...the First Officer points out that they're climbing too quickly. 503 00:33:30,777 --> 00:33:33,404 Why is he climbing so quickly? 504 00:33:35,782 --> 00:33:37,408 His mistakes are adding up. 505 00:33:39,494 --> 00:33:43,414 He's trying to overcompensate to get to his altitude. 506 00:33:43,414 --> 00:33:46,042 He's pitching up too fast. 507 00:33:46,042 --> 00:33:48,252 He's doing things too quickly. 508 00:33:48,961 --> 00:33:51,172 Was the nosedive just another mistake? 509 00:33:58,596 --> 00:34:01,432 How far are they telling us to climb? 510 00:34:02,809 --> 00:34:05,061 He still doesn't know his altitude clearance. 511 00:34:05,561 --> 00:34:07,939 It doesn't look like the First Officer knows either. 512 00:34:13,027 --> 00:34:14,696 Fif...1,500 feet, sir. 513 00:34:14,696 --> 00:34:16,447 Fif... 514 00:34:20,868 --> 00:34:22,328 They're talking in terms of feet, 515 00:34:22,328 --> 00:34:25,206 even though the controller's instructions were in metres. 516 00:34:26,499 --> 00:34:29,460 Investigators now realize the controller 517 00:34:29,460 --> 00:34:32,714 and the pilots are using different altitude measurements. 518 00:34:33,798 --> 00:34:36,384 Weren't they trained to use metric? 519 00:34:37,510 --> 00:34:39,387 Should be, but let's check. 520 00:34:40,471 --> 00:34:42,473 Certainly the more training you have 521 00:34:42,473 --> 00:34:45,643 that would have helped greatly in terms of sorting out 522 00:34:45,643 --> 00:34:47,520 the metres versus feet. 523 00:34:49,147 --> 00:34:51,315 I see. Thank you for your time. 524 00:34:52,150 --> 00:34:56,112 They look deeper into the training procedures for Korean Air pilots. 525 00:34:56,112 --> 00:34:58,531 Korean Air says the Seoul to Shanghai route 526 00:34:58,531 --> 00:35:01,325 is the only one where their pilots need to use metric. 527 00:35:02,368 --> 00:35:03,786 What kind of training did they have? 528 00:35:03,786 --> 00:35:07,123 They require their pilots to watch a single training video 529 00:35:07,123 --> 00:35:08,499 to learn metric conversion. 530 00:35:09,584 --> 00:35:11,377 According to the pilot records, 531 00:35:11,377 --> 00:35:15,715 the Captain had only flown into Shanghai once prior. 532 00:35:16,340 --> 00:35:19,135 The First Officer had never flown there before. 533 00:35:19,594 --> 00:35:22,221 Which means the First Officer would have watched 534 00:35:22,221 --> 00:35:24,849 the training video for the first time only that morning. 535 00:35:28,895 --> 00:35:31,522 Investigators conclude that the pilots 536 00:35:31,522 --> 00:35:35,610 of Flight 6316 confused metric and imperial... 537 00:35:35,610 --> 00:35:37,487 Fif... teen. 538 00:35:38,029 --> 00:35:40,990 ...because they were inadequately prepared for the flight. 539 00:35:40,990 --> 00:35:44,494 For the pilots to operate in a metric environment, 540 00:35:44,494 --> 00:35:47,872 this is something that you need to get into a simulator, 541 00:35:47,872 --> 00:35:49,332 and you need practise it. 542 00:35:49,332 --> 00:35:52,418 {\an8}Watching a video is just not going to be enough, period. 543 00:35:52,418 --> 00:35:55,922 So was the metric confusion the reason why they pushed 544 00:35:55,922 --> 00:35:57,590 the plane into a nosedive? 545 00:36:02,887 --> 00:36:04,931 How... How far did they tell us to climb? 546 00:36:04,931 --> 00:36:08,101 As the flight reaches its assigned altitude 547 00:36:08,101 --> 00:36:11,145 of 4,500 feet, or 1,500 metres... 548 00:36:11,145 --> 00:36:13,648 Fif...1,500 feet, sir. 549 00:36:13,648 --> 00:36:15,650 Fif... 550 00:36:15,650 --> 00:36:17,110 ...the First Officer leads the Captain 551 00:36:17,110 --> 00:36:20,405 to believe they should be much lower, at 1,500 feet. 552 00:36:20,988 --> 00:36:25,159 The Captain, thinking that they have blown through their clearance, 553 00:36:25,159 --> 00:36:27,787 would be extremely alarmed, because now, 554 00:36:27,787 --> 00:36:31,457 there is a very strong potential for a traffic conflict. 555 00:36:31,457 --> 00:36:38,089 Fifteen... I'm too high. 556 00:36:38,089 --> 00:36:41,009 Descend... descend... descend. 557 00:36:41,509 --> 00:36:45,972 The quickest response is to push forward on the controls. 558 00:36:49,726 --> 00:36:53,604 - Wait. Wait, wait, wait... - Just a moment. 559 00:36:53,604 --> 00:36:56,607 The Captain pushes the plane into a steep dive 560 00:36:56,607 --> 00:36:59,027 to descend to a much lower altitude. 561 00:37:03,990 --> 00:37:06,367 You can hear the Captain trim the plane down. 562 00:37:06,367 --> 00:37:08,369 He put them in the dive. 563 00:37:10,496 --> 00:37:12,832 He pitches the aircraft nose down, 564 00:37:12,832 --> 00:37:18,296 and simultaneously is trimming the horizontal stabilizer, 565 00:37:18,296 --> 00:37:20,965 which relieves the control column pressure. 566 00:37:20,965 --> 00:37:24,052 But the combination of these things put the aircraft 567 00:37:24,052 --> 00:37:27,472 into a dive from which it's almost impossible to recover. 568 00:37:28,890 --> 00:37:31,476 During descent, the First Officer suddenly 569 00:37:31,476 --> 00:37:34,020 recognises the seriousness of their situation. 570 00:37:34,020 --> 00:37:36,189 Wait, wait. Pitch 571 00:37:36,189 --> 00:37:37,899 O-oh-okay. Okay. 572 00:37:37,899 --> 00:37:43,488 But by the time the pilots realize the danger... 573 00:37:43,488 --> 00:37:45,490 Nose up, nose up, nose up. 574 00:37:45,490 --> 00:37:47,575 Pull up. 575 00:37:50,203 --> 00:37:51,537 ...it's too late. 576 00:37:55,625 --> 00:37:57,460 Investigators conclude that the crash 577 00:37:57,460 --> 00:38:01,923 was caused by the Captain's confusion over his altitude measurement. 578 00:38:02,423 --> 00:38:04,759 Even if the Captain thought he was too high, 579 00:38:04,759 --> 00:38:07,845 why not descend more gradually? 580 00:38:13,393 --> 00:38:16,354 Wait, wait, wait, wait. 581 00:38:19,941 --> 00:38:22,151 First, he climbed too quickly, 582 00:38:22,151 --> 00:38:24,195 then he descended way too quickly. 583 00:38:24,195 --> 00:38:27,323 Investigators try to determine why the Captain 584 00:38:27,323 --> 00:38:30,493 of Korean Air Flight 6316 reacted so drastically 585 00:38:30,493 --> 00:38:32,995 to his belief that the aircraft was too high? 586 00:38:32,995 --> 00:38:36,332 Maybe he was trying to cover up his mistakes? 587 00:38:39,377 --> 00:38:41,379 On one hand, the Captain knows 588 00:38:41,379 --> 00:38:44,799 it is dangerous when they're overshooting the altitude. 589 00:38:46,134 --> 00:38:47,885 How far did they tell us to climb? 590 00:38:47,885 --> 00:38:51,222 On the other hand, the Captain doesn't want 591 00:38:51,222 --> 00:38:53,933 the controller to know that he made a mistake. 592 00:38:53,933 --> 00:38:58,187 So he tried to get down quickly to save face. 593 00:38:58,771 --> 00:39:00,398 What I don't understand is, 594 00:39:00,398 --> 00:39:03,192 why didn't the First Officer try to stop him? 595 00:39:04,861 --> 00:39:07,739 Especially since he was guiding him earlier. 596 00:39:11,117 --> 00:39:13,453 There's a lot going on, and the First Officer 597 00:39:13,453 --> 00:39:17,749 is not only trying to read back the clearances 598 00:39:17,749 --> 00:39:21,669 but also trying to ensure that the Captain is turning 599 00:39:21,669 --> 00:39:24,005 in the direction that needs to be turned. 600 00:39:24,005 --> 00:39:25,006 Keep turning. 601 00:39:25,757 --> 00:39:28,092 - Keep turning? - Yes. Keep turning more. 602 00:39:32,680 --> 00:39:36,726 I've got the CVR all set for the moment before the dive. 603 00:39:38,061 --> 00:39:41,439 Did the First Officer ever recognize the error? 604 00:39:45,860 --> 00:39:47,528 How far did they tell us to climb? 605 00:39:47,528 --> 00:39:50,698 Fif... 1,500 feet, sir. 606 00:39:50,698 --> 00:39:53,910 Uh... oh. 607 00:39:58,289 --> 00:40:00,041 Wait. Wait, wait, wait. 608 00:40:00,416 --> 00:40:03,461 Investigators hear the First Officer hesitate 609 00:40:03,461 --> 00:40:06,631 after providing the Captain with the wrong altitude. 610 00:40:07,840 --> 00:40:11,427 Maybe at that point the First Officer recognized his mistake 611 00:40:11,427 --> 00:40:12,553 was feet and metres, we don't know. 612 00:40:12,553 --> 00:40:14,097 Just-just a moment. 613 00:40:20,019 --> 00:40:22,897 - Wait, pitch. - O-oh-okay. Okay. 614 00:40:27,985 --> 00:40:33,157 So the dive starts and he says: "Wait, wait, wait". 615 00:40:36,119 --> 00:40:43,000 Then after five full seconds of free fall, he says: "Wait, pitch". 616 00:40:44,961 --> 00:40:49,799 Clearly, there should have been some input, 617 00:40:49,799 --> 00:40:54,846 some effort from the First Officer to try to slow things down. 618 00:41:00,727 --> 00:41:04,105 In my opinion, the First Officer was speaking 619 00:41:04,105 --> 00:41:05,189 but he wasn't speaking up. 620 00:41:06,315 --> 00:41:08,192 Wait. Wait, wait, wait. 621 00:41:08,192 --> 00:41:10,027 Just-just a moment. 622 00:41:10,027 --> 00:41:13,197 He gave little hints that things were going wrong to the Captain, 623 00:41:13,197 --> 00:41:17,535 but it was apparent that the pilots were not on the same page. 624 00:41:24,834 --> 00:41:28,004 At the end of the day, the Captain caused the dive. 625 00:41:30,048 --> 00:41:31,674 He overreacted. 626 00:41:34,218 --> 00:41:35,845 The rate of descent was so high, 627 00:41:35,845 --> 00:41:39,974 that now it became very difficult to recover 628 00:41:39,974 --> 00:41:42,852 once you got down to the lower altitudes. 629 00:41:42,852 --> 00:41:46,773 And probably, they didn't realize the trouble they were in 630 00:41:46,773 --> 00:41:48,900 until they could see breaks in the clouds and see the ground. 631 00:41:48,900 --> 00:41:50,026 Terrain, terrain. 632 00:41:50,026 --> 00:41:51,652 Nose up, nose up, nose up. 633 00:41:51,652 --> 00:41:54,697 Pull up... Pull up. 634 00:42:00,244 --> 00:42:04,165 In their final report, investigators conclude that confusion 635 00:42:04,165 --> 00:42:07,377 over the metric system led the First Officer 636 00:42:07,377 --> 00:42:09,712 to relay the wrong altitude. 637 00:42:09,712 --> 00:42:12,590 How far did they tell us to climb? 638 00:42:12,590 --> 00:42:15,218 Fif... 1,500 hundred feet, sir. 639 00:42:15,885 --> 00:42:19,597 That mistake caused the Captain to overcompensate... 640 00:42:21,307 --> 00:42:22,642 Wait. Wait, wait. 641 00:42:22,642 --> 00:42:24,060 Just-just one moment. 642 00:42:24,060 --> 00:42:26,771 ...and push the aircraft into a fatal dive. 643 00:42:29,190 --> 00:42:32,694 We can look at this as a training accident, 644 00:42:32,694 --> 00:42:34,779 as much as anything else. 645 00:42:34,779 --> 00:42:38,866 The way the pilots were trained at that time resulted 646 00:42:38,866 --> 00:42:44,414 in a series of decisions and actions that put the airplane 647 00:42:44,414 --> 00:42:46,791 in an unrecoverable situation. 648 00:42:47,625 --> 00:42:50,545 In Chinese aviation industry, we have a motto: 649 00:42:50,545 --> 00:42:54,132 Every line in the checklist is written in blood. 650 00:42:54,132 --> 00:42:57,844 Because behind every line in the checklist is a disaster, 651 00:42:57,844 --> 00:43:01,055 but it's an opportunity to improve. 652 00:43:02,890 --> 00:43:05,727 One of the recommendations was that Korean Air reinforce 653 00:43:05,727 --> 00:43:08,813 its cockpit resource management training. 654 00:43:08,813 --> 00:43:12,442 It's part of the fabric that holds a safe flight together. 655 00:43:12,442 --> 00:43:15,445 And that includes things like a pre-takeoff briefing. 656 00:43:15,445 --> 00:43:19,657 So these are some of the items that, in my mind, were most important. 657 00:43:22,243 --> 00:43:25,079 Today, Korean Air is recognized 658 00:43:25,079 --> 00:43:27,665 as one of the safest airlines in the world. 659 00:43:30,418 --> 00:43:34,464 The amount of standardization through all the airlines, 660 00:43:34,464 --> 00:43:38,092 the amount of training now is a much higher level than it was before. 661 00:43:38,092 --> 00:43:42,096 The digital airplanes, there's a button you can turn, 662 00:43:42,096 --> 00:43:45,099 and all your display shows metres instead of feet. 663 00:43:46,267 --> 00:43:50,480 But it does bring up the need for vigilance. 664 00:43:50,480 --> 00:43:53,149 This crew made so many errors. 665 00:43:53,149 --> 00:43:57,362 Losing control of a big airplane is very unusual. 666 00:43:57,362 --> 00:43:59,989 And hopefully, we won't see it again. 667 00:44:28,643 --> 00:44:31,062 Subtitling: difuze