1 00:00:02,586 --> 00:00:04,620 Outside one of India's busiest airports, 2 00:00:04,724 --> 00:00:07,482 the early evening sky ignites into a fireball. 3 00:00:08,689 --> 00:00:09,965 This cloud just lit up, 4 00:00:10,068 --> 00:00:12,103 it felt like you could feel the heat. 5 00:00:12,206 --> 00:00:14,137 Flaming wreckage falls from the sky. 6 00:00:15,724 --> 00:00:17,896 It's a horrifying crash. 7 00:00:18,000 --> 00:00:21,689 I realized that the clumps that I saw all around were 8 00:00:21,793 --> 00:00:24,000 either the remnants of the aircraft, or dead bodies. 9 00:00:27,379 --> 00:00:28,827 When investigators arrive, 10 00:00:28,931 --> 00:00:32,689 they find the twisted remains of two passenger jets. 11 00:00:32,793 --> 00:00:36,206 Three hundred and forty-nine people are dead. 12 00:00:36,310 --> 00:00:38,793 Vital clues are buried deep underground. 13 00:00:41,310 --> 00:00:43,551 Investigators must piece together the day's events. 14 00:00:44,344 --> 00:00:48,068 Saudi 763 will maintain 140. 15 00:00:48,172 --> 00:00:51,689 Kazakh 1907 now reach 150. 16 00:00:51,793 --> 00:00:54,275 How had two crews that should have known 17 00:00:54,379 --> 00:00:56,068 each other's positions... 18 00:00:56,172 --> 00:00:59,000 ended up in the worlds deadliest mid-air collision. 19 00:01:03,413 --> 00:01:05,482 Mayday! Mayday! 20 00:01:26,689 --> 00:01:30,344 Indira Gandhi International Airport, New Delhi. 21 00:01:32,172 --> 00:01:33,862 A Gateway to India. 22 00:01:44,103 --> 00:01:46,793 November the 12th, 1996. 23 00:01:47,827 --> 00:01:49,827 Busy? 24 00:01:49,931 --> 00:01:52,206 Air Traffic Controller VK Dutta arrives 25 00:01:52,310 --> 00:01:54,206 for the late afternoon shift. 26 00:01:57,068 --> 00:01:59,000 There was one supervisory officer. 27 00:01:59,103 --> 00:02:01,827 There was one person who was sitting beside me 28 00:02:01,931 --> 00:02:03,965 and he was assisting me. 29 00:02:04,068 --> 00:02:06,448 And... the things were all normal. 30 00:02:08,896 --> 00:02:12,000 But normal at Indira Gandhi doesn't mean calm. 31 00:02:13,482 --> 00:02:15,172 This is becoming one of the most 32 00:02:15,275 --> 00:02:17,172 congested airports in the world. 33 00:02:17,275 --> 00:02:19,896 In 1990, the Government of India signed 34 00:02:20,000 --> 00:02:23,068 open skies agreements with several different countries. 35 00:02:23,172 --> 00:02:24,344 Those pacts have made it easier 36 00:02:24,448 --> 00:02:27,379 for foreign airlines to land at Indian airports. 37 00:02:29,482 --> 00:02:32,724 Many airlines are taking advantage of the new policy. 38 00:02:34,862 --> 00:02:38,551 Air traffic controllers are now handling more traffic than ever. 39 00:02:40,965 --> 00:02:46,000 The open skies policy acted as a catalyst in the air traffic growth. 40 00:02:48,137 --> 00:02:54,413 The volume of traffic grew from, I believe, 175 movements a day 41 00:02:54,517 --> 00:02:56,482 to around 225 movements a day. 42 00:02:57,896 --> 00:02:59,103 We have to perform... 43 00:02:59,206 --> 00:03:01,517 we have to perform, uh, during that time. 44 00:03:01,620 --> 00:03:04,551 So whether 10 aircraft come on that time, or 20 comes, 45 00:03:04,655 --> 00:03:06,241 so, you have to handle them. 46 00:03:09,275 --> 00:03:11,103 Just past six o'clock, 47 00:03:11,206 --> 00:03:15,551 Saudi Arabian Airlines Flight 763 takes off into the sunset. 48 00:03:19,413 --> 00:03:20,793 Gear up. 49 00:03:22,586 --> 00:03:23,689 Gear up. 50 00:03:24,586 --> 00:03:26,172 Clear on left. 51 00:03:26,275 --> 00:03:28,000 Captain Khalid Al-Shubaily 52 00:03:28,103 --> 00:03:31,793 powers the Boeing 747 away from the runway. 53 00:03:31,896 --> 00:03:35,551 His Co-Pilot Nazir Khan handles all radio communication. 54 00:03:38,931 --> 00:03:41,275 There are 289 passengers on board. 55 00:03:43,551 --> 00:03:47,034 Many are Indian workers returning to their jobs in the Middle East. 56 00:03:51,068 --> 00:03:54,689 Saudi 763. Airborne 03, 57 00:03:54,793 --> 00:03:58,758 contact radar 127 decimal 9. 58 00:03:58,862 --> 00:04:01,586 While Flight 763 was on the runway, 59 00:04:01,689 --> 00:04:03,413 its movements were tracked and directed 60 00:04:03,517 --> 00:04:06,103 by an Air Traffic Controller in the airport's tower. 61 00:04:08,896 --> 00:04:10,413 279. Good day. 62 00:04:12,551 --> 00:04:15,000 But shortly after the plane takes off, 63 00:04:15,103 --> 00:04:17,068 the Tower passes the pilots over to 64 00:04:17,172 --> 00:04:19,103 Approach Controller VK Dutta, 65 00:04:19,206 --> 00:04:21,000 who's in another room at the airport. 66 00:04:23,655 --> 00:04:25,793 Approach Controllers at Indira Gandhi 67 00:04:25,896 --> 00:04:28,655 guide planes through the airspace beyond the runways. 68 00:04:30,758 --> 00:04:35,586 They're in charge of all arriving and departing flights within 110 kilometers. 69 00:04:38,034 --> 00:04:39,724 The Approach Controller normally 70 00:04:39,827 --> 00:04:44,310 is responsible for arrival and departures of the aircraft 71 00:04:44,413 --> 00:04:45,413 which are coming in. 72 00:04:45,517 --> 00:04:48,310 They are safely and expeditiously, you know, 73 00:04:48,413 --> 00:04:50,827 they are brought to the final approach. 74 00:04:50,931 --> 00:04:53,758 Tonight, Dutta is controlling five flights. 75 00:04:53,862 --> 00:04:55,724 Some of these are leaving the airport, 76 00:04:55,827 --> 00:04:57,034 while others are coming in. 77 00:04:58,689 --> 00:05:02,482 His task is to keep those planes spaced safely apart, 78 00:05:02,586 --> 00:05:06,103 but not so far apart as to cause any delays. 79 00:05:06,206 --> 00:05:09,137 There is continuous coordination with the tower 80 00:05:09,241 --> 00:05:10,931 who handles the ground traffic. 81 00:05:11,034 --> 00:05:12,551 So he would tell approach controller 82 00:05:12,655 --> 00:05:15,827 that this fellow is ready, and, you know, uh... 83 00:05:15,931 --> 00:05:18,689 he is to be accommodated between these two flights. 84 00:05:18,793 --> 00:05:22,310 So that kind of dynamics we do... 85 00:05:22,413 --> 00:05:24,310 we were doing at that time. 86 00:05:24,413 --> 00:05:27,689 Saudi 763, approaching flight level 100. 87 00:05:28,551 --> 00:05:32,172 Roger, climb flight level 140. 88 00:05:34,724 --> 00:05:37,965 Clear to climb 140, Saudi 763. 89 00:05:40,379 --> 00:05:43,241 This evening, a United States Air Force cargo plane 90 00:05:43,344 --> 00:05:45,000 is coming in for a landing. 91 00:05:47,689 --> 00:05:49,620 Even though it's an Air Force jet, 92 00:05:49,724 --> 00:05:51,758 this flight is Dutta's responsibility. 93 00:05:55,344 --> 00:05:58,034 I think we probably had three or four 94 00:05:58,137 --> 00:06:00,689 back and forths with the controller, 95 00:06:00,793 --> 00:06:03,103 where he was verifying our altitude, 96 00:06:03,206 --> 00:06:04,655 or checking on our altitude, 97 00:06:04,758 --> 00:06:06,586 telling us about other traffic in the vicinity. 98 00:06:08,379 --> 00:06:12,034 Saudi 763, approaching 1-4-0 for higher. 99 00:06:12,137 --> 00:06:17,517 Saudi Flight 763 reaches its last assigned altitude of 14,000 feet. 100 00:06:17,620 --> 00:06:20,724 The pilots request permission to fly higher. 101 00:06:20,827 --> 00:06:23,241 Roger, maintain flight level 140. 102 00:06:23,344 --> 00:06:25,275 Stand-by for higher. 103 00:06:25,379 --> 00:06:28,620 In order to coordinate incoming and outgoing traffic, 104 00:06:28,724 --> 00:06:30,758 Dutta wants the Saudi flight to stop climbing. 105 00:06:31,896 --> 00:06:34,482 Saudi 763 will maintain 140. 106 00:06:35,896 --> 00:06:38,310 Dutta is concerned with another plane, 107 00:06:38,413 --> 00:06:41,758 now flying east for a landing at Indira Gandhi Airport. 108 00:06:41,862 --> 00:06:45,068 It's a passenger jet operated by Kazakhstan Airlines. 109 00:06:46,758 --> 00:06:50,068 The Ilyushin-76 is a massive Russian plane. 110 00:06:50,172 --> 00:06:52,034 Originally built for the military, 111 00:06:52,137 --> 00:06:56,517 a modified version is now widely used as a commercial airliner. 112 00:06:56,620 --> 00:06:59,103 Dutta wants it to pass over top of the Saudi flight before landing. 113 00:06:59,206 --> 00:07:00,862 before landing. 114 00:07:00,965 --> 00:07:03,862 After that, he'll let the Saudis continue their climb. 115 00:07:05,034 --> 00:07:06,379 They were supposed to cross, 116 00:07:06,482 --> 00:07:08,310 uh, maintaining a 1000 feet of separation. 117 00:07:09,206 --> 00:07:13,344 Kazakh 1907, now reaching 150. 118 00:07:13,448 --> 00:07:17,482 46 miles from Delta Papa November. 119 00:07:20,275 --> 00:07:23,517 Roger, maintain flight level 150. 120 00:07:23,620 --> 00:07:27,344 Identified traffic 12 o'clock reciprocal, Saudi Boeing 747. 121 00:07:31,000 --> 00:07:35,862 Dutta doesn't want the Kazakh flight to be surprised to see the Saudi jet. 122 00:07:35,965 --> 00:07:39,103 Since planes don't have radar to track other aircraft, 123 00:07:39,206 --> 00:07:42,448 they rely on controllers to warn them about other planes nearby. 124 00:07:44,103 --> 00:07:46,344 Maintaining 150, 125 00:07:46,448 --> 00:07:49,206 Kazakh 1907. Will report. 126 00:07:50,896 --> 00:07:52,137 How many miles? 127 00:07:53,931 --> 00:07:55,896 All pilots tuned to the approach control 128 00:07:56,000 --> 00:07:58,517 radio frequency are able to hear one another 129 00:07:58,620 --> 00:08:00,310 as they communicate with the ground. 130 00:08:02,000 --> 00:08:03,103 How many miles? 131 00:08:03,827 --> 00:08:05,793 Eight miles now. 132 00:08:05,896 --> 00:08:06,965 It was strictly visual, 133 00:08:08,172 --> 00:08:10,172 and trying to, trying to pick up on the radios 134 00:08:10,275 --> 00:08:12,000 where everyone else is at, and what they're up to. 135 00:08:12,103 --> 00:08:16,689 Traffic is at eight miles level 140. 136 00:08:16,793 --> 00:08:19,758 Suddenly, a massive explosion shatters the evening's calm. 137 00:08:27,103 --> 00:08:29,310 All at once, out of the right side of the window, 138 00:08:29,413 --> 00:08:33,655 right side of the cockpit, um, this cloud just lit up. 139 00:08:35,517 --> 00:08:36,965 Are those missiles? 140 00:08:37,068 --> 00:08:39,517 To my mind's eye they were missiles 141 00:08:39,620 --> 00:08:42,655 kind of cork screwing picking up speed was what they looked like. 142 00:08:42,758 --> 00:08:44,620 And they looked like they were coming right at us. 143 00:08:44,724 --> 00:08:47,275 We actually started veering the aircraft away 144 00:08:47,379 --> 00:08:51,413 before it became apparent that they weren't coming at us. 145 00:09:08,034 --> 00:09:11,034 The Saudi Airlines jet spirals towards the ground. 146 00:09:13,103 --> 00:09:14,827 Delhi, this is 1815. 147 00:09:16,655 --> 00:09:19,034 1815, say again. 148 00:09:19,137 --> 00:09:21,275 Got on the radio right away called the controller. 149 00:09:21,379 --> 00:09:23,758 We saw something that looks like a big explosion. 150 00:09:23,862 --> 00:09:27,724 Then it struck me that something has gone wrong. 151 00:09:27,827 --> 00:09:30,379 On Dutta's radar screen, both the Saudi jet 152 00:09:30,482 --> 00:09:32,758 and the Kazakh plane have simply vanished. 153 00:09:34,482 --> 00:09:36,137 When I saw the blips are coming, 154 00:09:36,241 --> 00:09:38,172 and so I watched the sweep again. 155 00:09:46,758 --> 00:09:48,344 But they were not there at all. 156 00:09:51,758 --> 00:09:54,551 We then heard the controller call for... 157 00:09:54,655 --> 00:09:57,275 for the Saudi Air jet and the Ilyushin. 158 00:09:57,379 --> 00:09:58,931 Saudi 763? 159 00:10:00,793 --> 00:10:02,586 With no response. 160 00:10:02,689 --> 00:10:05,689 That was obviously very bone chilling. 161 00:10:10,620 --> 00:10:14,068 Something tragic has happened in the skies near New Delhi's airport. 162 00:10:16,379 --> 00:10:19,724 VK Dutta is about to become the target of an investigation 163 00:10:19,827 --> 00:10:22,655 into one of the deadliest plane crashes of all time. 164 00:10:26,275 --> 00:10:28,172 Kazakh 1907, report your position. 165 00:10:32,482 --> 00:10:33,862 At New Delhi's airport, 166 00:10:33,965 --> 00:10:36,172 a sense of dread is growing. 167 00:10:39,034 --> 00:10:42,344 Two planes have vanished from Approach Control's radar. 168 00:10:44,448 --> 00:10:46,241 The worst nightmare 169 00:10:47,103 --> 00:10:49,620 an air traffic controller 170 00:10:49,724 --> 00:10:52,551 has is the mid-air collision. 171 00:10:53,482 --> 00:10:54,551 Saudi 763? 172 00:10:59,344 --> 00:11:01,137 Together, the two missing planes 173 00:11:01,241 --> 00:11:03,862 were carrying 349 people. 174 00:11:07,620 --> 00:11:09,000 Kazakh 1907, report position. 175 00:11:11,103 --> 00:11:13,896 I gave one or two calls to Kazakh and Saudi. 176 00:11:15,344 --> 00:11:16,413 Saudi 763? 177 00:11:17,586 --> 00:11:19,448 I forgot how many kids I have, 178 00:11:19,551 --> 00:11:21,551 where my wife is, whom I'm related to. 179 00:11:27,758 --> 00:11:30,137 US Air Force Pilot Captain Tim Place 180 00:11:30,241 --> 00:11:32,275 soon confirms the worst. 181 00:11:34,448 --> 00:11:35,931 Delhi, this is 1815. 182 00:11:36,793 --> 00:11:39,620 1815, what did you see? 183 00:11:39,724 --> 00:11:41,896 Two distinct fires on the ground. 184 00:11:42,000 --> 00:11:44,068 Two fires on the ground. 185 00:11:44,172 --> 00:11:45,344 Confirm? 186 00:11:45,448 --> 00:11:46,758 Confirmed. 187 00:11:46,862 --> 00:11:48,000 Confirmed. 188 00:11:51,379 --> 00:11:52,275 Roger. 189 00:11:55,000 --> 00:11:56,275 My senior came to me, 190 00:11:56,379 --> 00:11:58,000 so I told him, uh... 191 00:11:58,931 --> 00:12:00,275 an accident had happened. 192 00:12:02,206 --> 00:12:05,689 I told our people who were to do the search and rescue 193 00:12:05,793 --> 00:12:08,068 that the aircraft have crashed 194 00:12:08,172 --> 00:12:10,137 at 40 nautical miles west of Delhi. 195 00:12:11,655 --> 00:12:14,206 Two planes have gone down over Charkhi Dadri. 196 00:12:17,310 --> 00:12:21,241 Charkhi Dadri is a town 65 kilometres west of New Delhi. 197 00:12:29,724 --> 00:12:32,344 Its mustard and grain fields are now burning 198 00:12:32,448 --> 00:12:35,206 with the twisted wreckage of two ruined airplanes. 199 00:12:39,689 --> 00:12:42,068 All of a sudden, the sky turned a bright red color, 200 00:12:42,172 --> 00:12:44,172 and I saw fire and smoke. 201 00:12:49,000 --> 00:12:51,206 One plane started to come towards us. 202 00:12:51,310 --> 00:12:54,241 There was fire and parts of the plane were flying everywhere. 203 00:12:54,344 --> 00:12:57,241 People were running. The plane's engine broke off 204 00:12:57,344 --> 00:13:00,724 and the plane started to spin out of control and fell into the field. 205 00:13:08,827 --> 00:13:10,793 I was told that there's been a mid-air collision. 206 00:13:10,896 --> 00:13:13,344 Apparently there's a jumbo jet which may be involved, 207 00:13:13,448 --> 00:13:14,551 and why don't you just head out? 208 00:13:16,379 --> 00:13:19,310 There was this adrenaline rush in that sense, I was... 209 00:13:19,413 --> 00:13:20,689 I was very new in the business, 210 00:13:20,793 --> 00:13:23,310 and I knew I had to get that story. 211 00:13:23,413 --> 00:13:25,206 Vishnu Som is assigned to report 212 00:13:25,310 --> 00:13:28,000 on the crash for New Delhi Television. 213 00:13:28,103 --> 00:13:32,172 He arrives in the darkness of night, a few hours after the crash. 214 00:13:32,275 --> 00:13:35,379 We parked our vehicle on the side of the road, 215 00:13:35,482 --> 00:13:36,965 and it was a... 216 00:13:37,068 --> 00:13:38,551 I mean, there was a fair bit of moonlight. 217 00:13:39,413 --> 00:13:40,724 He and his cameraman 218 00:13:40,827 --> 00:13:43,344 are one of the first media crews to arrive on the scene. 219 00:13:43,448 --> 00:13:44,275 Turn off the light. 220 00:13:45,620 --> 00:13:46,689 We don't want to attract attention. 221 00:13:48,931 --> 00:13:50,379 The police have likely cordoned off the area. 222 00:13:54,724 --> 00:13:56,379 I stepped onto the field, 223 00:13:56,482 --> 00:13:59,344 and, I mean, I thought it was a fallow field, 224 00:13:59,448 --> 00:14:02,551 nothing was growing over there, because it was just sand. 225 00:14:02,655 --> 00:14:05,172 Um, and you know, because it was dark 226 00:14:05,275 --> 00:14:07,862 and our only visual reference was, was the moonlight, 227 00:14:07,965 --> 00:14:09,551 we just sort of kept going. 228 00:14:09,655 --> 00:14:12,000 And then, I remember seeing clumps around me. 229 00:14:12,103 --> 00:14:15,620 You know, just these, these little piles on, on all sides. 230 00:14:15,724 --> 00:14:19,000 And because there wasn't enough light, I didn't know what exactly it was. 231 00:14:19,103 --> 00:14:20,517 And then I stopped, because I said, you know, 232 00:14:20,620 --> 00:14:22,655 something's terribly wrong over here. 233 00:14:22,758 --> 00:14:23,620 Turn on your lights. 234 00:14:24,862 --> 00:14:25,689 Turn on your light. 235 00:14:28,965 --> 00:14:32,827 I realized that the clumps that I saw all around me were 236 00:14:32,931 --> 00:14:35,689 either the remnants of the aircraft, or dead bodies. 237 00:14:37,241 --> 00:14:39,724 There was a tree just maybe 238 00:14:39,827 --> 00:14:43,724 fifteen feet away from me to my right. 239 00:14:43,827 --> 00:14:46,413 There was this burnt corpse on that tree, 240 00:14:46,517 --> 00:14:49,689 and that's an image which, which, you know, comes back 241 00:14:49,793 --> 00:14:52,862 and continues to haunt me even after so many years. 242 00:14:57,586 --> 00:14:59,862 As night turns to day, 243 00:14:59,965 --> 00:15:02,310 hope of finding any survivors fades. 244 00:15:05,137 --> 00:15:07,931 None of the passengers aboard either plane has survived. 245 00:15:12,413 --> 00:15:14,655 Three hundred and forty-nine people are dead. 246 00:15:16,689 --> 00:15:19,724 It's the worst mid-air collision of all time. 247 00:15:21,379 --> 00:15:24,586 News of the crash spreads around the world. 248 00:15:24,689 --> 00:15:26,310 What remains clear is that there was more than 249 00:15:26,413 --> 00:15:29,137 one set of factors that might have resulted in the collision. 250 00:15:32,000 --> 00:15:35,241 We have two very separate wreckage fields. 251 00:15:36,310 --> 00:15:38,034 Captain KPS Nair 252 00:15:38,137 --> 00:15:40,068 is one of the first investigators on the scene. 253 00:15:46,586 --> 00:15:47,758 I was aghast, 254 00:15:48,827 --> 00:15:50,724 horrified. 255 00:15:50,827 --> 00:15:55,827 I can't explain it, because I had never seen anything like that before. 256 00:15:55,931 --> 00:15:57,206 It is something... 257 00:16:00,758 --> 00:16:01,896 which I can't explain. 258 00:16:04,482 --> 00:16:07,034 The Kazakh flight and the Saudi Airlines jet 259 00:16:07,137 --> 00:16:10,344 have fallen seven kilometres from each other. 260 00:16:10,448 --> 00:16:13,586 Investigators have two separate crash sites to examine. 261 00:16:13,689 --> 00:16:17,482 But they know one cause will explain both accidents. 262 00:16:19,551 --> 00:16:22,517 It's unlike a single aircraft falling somewhere. 263 00:16:22,620 --> 00:16:25,241 Two large body aircraft 264 00:16:25,344 --> 00:16:27,517 colliding with each other 265 00:16:27,620 --> 00:16:30,827 in the sky... There are different causes. 266 00:16:34,137 --> 00:16:38,655 How had two planes that were supposed to be 1,000 feet apart collided? 267 00:16:40,241 --> 00:16:43,551 Investigators consider three possibilities. 268 00:16:43,655 --> 00:16:46,896 An error on the part of the air traffic controller, 269 00:16:47,000 --> 00:16:49,206 an error by one of the crews, 270 00:16:49,310 --> 00:16:52,068 or the failure of an instrument on one of the planes. 271 00:16:55,620 --> 00:16:59,000 They hope the mangled wreckage will hold the clues they need. 272 00:17:02,103 --> 00:17:06,103 Their first priority is to find the black boxes from both planes. 273 00:17:06,206 --> 00:17:08,172 They record cockpit conversations 274 00:17:08,275 --> 00:17:10,413 along with critical data about the flight, 275 00:17:10,517 --> 00:17:12,586 like its altitude, speed and heading. 276 00:17:14,241 --> 00:17:16,862 Although fire has ravaged the wreck sites, 277 00:17:16,965 --> 00:17:18,655 the black boxes from both planes 278 00:17:18,758 --> 00:17:21,000 are found on the first day of the investigation. 279 00:17:28,000 --> 00:17:31,068 But for the moment, they hold their secrets. 280 00:17:31,172 --> 00:17:35,000 It will take several months for experts to extract data from the recorders. 281 00:17:38,862 --> 00:17:41,827 In the meantime, investigators focus on conversations 282 00:17:41,931 --> 00:17:44,344 between the two planes and the air traffic controller. 283 00:17:45,379 --> 00:17:47,724 In this particular case, we... 284 00:17:49,172 --> 00:17:52,655 had the evidence of the ATC transcript. 285 00:17:54,206 --> 00:17:55,793 Without onboard radar, 286 00:17:55,896 --> 00:17:57,482 the planes around Delhi's airport 287 00:17:57,586 --> 00:17:59,379 rely on air traffic controllers to guide them. 288 00:18:00,758 --> 00:18:03,965 VK Dutta comes under enormous pressure. 289 00:18:04,068 --> 00:18:07,827 Did he make mistakes that caused the worst mid-air collision ever? 290 00:18:08,862 --> 00:18:10,103 Those times were bad. 291 00:18:10,206 --> 00:18:13,344 These media people, they cried foul. 292 00:18:13,448 --> 00:18:16,551 So I told them that, you know, there's no fault of mine. 293 00:18:16,655 --> 00:18:18,827 Hi, I'm VK Dutta. 294 00:18:18,931 --> 00:18:21,000 I'm sorry to keep you waiting. 295 00:18:21,103 --> 00:18:22,482 Have a seat. 296 00:18:22,586 --> 00:18:24,413 Investigators want to know everything 297 00:18:24,517 --> 00:18:26,275 that Dutta did on the night of the crash. 298 00:18:27,103 --> 00:18:28,034 Was traffic heavy? 299 00:18:29,241 --> 00:18:31,793 Evenings are always busy. 300 00:18:31,896 --> 00:18:35,068 Dutta's radar doesn't track a plane's altitude. 301 00:18:35,172 --> 00:18:37,103 Instead, controllers in New Delhi 302 00:18:37,206 --> 00:18:40,482 write a plane's last reported position on a strip of paper. 303 00:18:40,586 --> 00:18:43,103 The strips are continually updated. 304 00:18:43,206 --> 00:18:45,448 It's the only way for controllers to keep track 305 00:18:45,551 --> 00:18:47,862 of the altitude of the planes under their control. 306 00:18:50,758 --> 00:18:52,344 Level information is not there. 307 00:18:52,448 --> 00:18:54,793 So level has to be confirmed by the pilot. 308 00:18:57,000 --> 00:19:01,724 Kazakh 1907 now reaching 150. 309 00:19:01,827 --> 00:19:04,655 Air traffic controllers can only know a plane's altitude 310 00:19:04,758 --> 00:19:06,000 when the pilots report it. 311 00:19:09,137 --> 00:19:10,655 Are these your notes? 312 00:19:10,758 --> 00:19:13,103 Yes, sir. This is the Kazakh one, 313 00:19:13,206 --> 00:19:15,206 and this is the Saudi one. 314 00:19:15,310 --> 00:19:17,448 Investigators learn that Dutta was in charge 315 00:19:17,551 --> 00:19:19,448 of five flights at the time of the accident. 316 00:19:21,206 --> 00:19:23,241 And that the Saudi and Kazakh flights were flying 317 00:19:23,344 --> 00:19:26,068 in opposite directions of the same aerial pathway. 318 00:19:28,275 --> 00:19:33,482 The area that Dutta manages is divided into a network of air corridors. 319 00:19:33,586 --> 00:19:37,034 Controllers use them to channel flights in and out of the airport. 320 00:19:38,551 --> 00:19:41,655 But many of the corridors are used for military flights. 321 00:19:41,758 --> 00:19:44,206 In fact, even at such a busy airport, 322 00:19:44,310 --> 00:19:47,068 there's only one main corridor for commercial planes. 323 00:19:50,068 --> 00:19:53,724 In cases like this, there are strict rules he has to follow. 324 00:19:53,827 --> 00:19:57,310 Between two aircraft the requirements specify 325 00:19:57,413 --> 00:20:02,034 a vertical minimum separation of 1,000 feet. 326 00:20:02,137 --> 00:20:04,137 When aircraft fly through the sky, 327 00:20:04,241 --> 00:20:07,206 they leave turbulence in their wake, like boats on the water. 328 00:20:08,379 --> 00:20:10,206 It can affect the planes around them. 329 00:20:10,310 --> 00:20:12,137 Air Traffic Controllers deal with this 330 00:20:12,241 --> 00:20:15,275 by keeping planes at different altitudes. 331 00:20:15,379 --> 00:20:19,241 Roger, maintain flight level 140. Standby for higher. 332 00:20:19,344 --> 00:20:21,758 Dutta was supposed to ensure that the two planes 333 00:20:21,862 --> 00:20:25,241 were 1,000 feet apart as they approached each other. 334 00:20:25,344 --> 00:20:27,827 He planned to do what he had done many times before. 335 00:20:27,931 --> 00:20:30,241 Have the incoming plane pass 1,000 feet 336 00:20:30,344 --> 00:20:32,034 over the top of the outbound plane. 337 00:20:33,310 --> 00:20:35,931 It was a routine procedure, but somehow, 338 00:20:36,034 --> 00:20:39,206 the two planes had ended up on a collision course. 339 00:20:39,310 --> 00:20:42,206 One of the two planes was not where it should have been. 340 00:20:42,310 --> 00:20:45,586 Investigators wonder if Dutta made a mistake 341 00:20:45,689 --> 00:20:47,896 that led to the horrific crash. 342 00:20:52,310 --> 00:20:54,275 Pouring through the ATC transcripts, 343 00:20:54,379 --> 00:20:56,827 investigators quickly learn that Dutta had given 344 00:20:56,931 --> 00:20:59,689 the two planes the proper directions. 345 00:20:59,793 --> 00:21:02,482 But since his radar doesn't display altitude, 346 00:21:02,586 --> 00:21:05,965 there was no way for him to tell if the planes followed those instructions. 347 00:21:08,000 --> 00:21:11,862 Investigators are so convinced that Dutta did nothing wrong 348 00:21:11,965 --> 00:21:15,275 that three days after the crash he's back on duty. 349 00:21:15,379 --> 00:21:18,862 When my family and other people heard this, 350 00:21:18,965 --> 00:21:20,241 there was a little sigh of relief, 351 00:21:20,344 --> 00:21:22,103 that, you know, our guy is safe. 352 00:21:23,689 --> 00:21:26,068 Investigators return to the crash site. 353 00:21:26,172 --> 00:21:29,655 They are hoping to recover certain instruments from the two aircraft. 354 00:21:29,758 --> 00:21:31,758 Perhaps a mechanical failure had led 355 00:21:31,862 --> 00:21:33,517 one of the planes off course. 356 00:21:33,620 --> 00:21:39,068 Normally, the altimeter would have stopped at the point 357 00:21:39,172 --> 00:21:41,482 where the accident took place. 358 00:21:42,551 --> 00:21:45,827 And we wanted to know what altitude 359 00:21:45,931 --> 00:21:49,655 they were registering at the time of the accident. 360 00:21:52,000 --> 00:21:55,000 But the Saudi cockpit has plunged deep into the ground. 361 00:21:56,517 --> 00:21:59,448 The accident investigation becomes an excavation. 362 00:22:02,724 --> 00:22:08,103 The Saudis' nose portion was well below the earth. 363 00:22:08,206 --> 00:22:13,413 It was about 10 to 12 meters, um, below. 364 00:22:13,517 --> 00:22:16,034 The end of the nose had gone that far below. 365 00:22:17,275 --> 00:22:19,000 Machines had to be brought in. 366 00:22:20,689 --> 00:22:26,689 Excavators to dig up and lift the cockpit of the Saudi aircraft. 367 00:22:30,551 --> 00:22:34,103 The altimeters of the Kazakh flight are easier to find. 368 00:22:34,206 --> 00:22:36,275 That plane didn't crash nose first. 369 00:22:37,931 --> 00:22:39,965 There's some chance there are clues about 370 00:22:40,068 --> 00:22:42,103 its exact altitude at the time of the accident. 371 00:22:44,310 --> 00:22:46,034 When they're pulled from the wreckage, 372 00:22:46,137 --> 00:22:48,793 investigators discover that there is indeed 373 00:22:48,896 --> 00:22:50,551 something strange about the altimeters. 374 00:22:53,758 --> 00:22:55,551 Both the captain and the co-pilot 375 00:22:55,655 --> 00:22:57,586 have an altimeter in front of them. 376 00:22:57,689 --> 00:23:01,344 But in this case, they do not have same reading. 377 00:23:01,448 --> 00:23:03,793 There was a difference between the two 378 00:23:03,896 --> 00:23:06,586 by about 300 feet. 379 00:23:08,724 --> 00:23:09,827 Strange. 380 00:23:11,310 --> 00:23:12,965 Perhaps the conflicting altimeters 381 00:23:13,068 --> 00:23:15,379 had led the crew off course. 382 00:23:15,482 --> 00:23:16,655 But the difference in readings 383 00:23:16,758 --> 00:23:19,000 may simply have been caused by the force of the crash. 384 00:23:20,206 --> 00:23:22,448 At this point, investigators don't know. 385 00:23:25,034 --> 00:23:27,586 Mostly there, and there. 386 00:23:27,689 --> 00:23:28,793 As close as you can get. 387 00:23:29,965 --> 00:23:31,517 Investigators need to discover 388 00:23:31,620 --> 00:23:33,724 which of the two planes was at the wrong altitude. 389 00:23:34,758 --> 00:23:37,068 They explore other evidence. 390 00:23:37,172 --> 00:23:38,827 The pattern of the damage on the two planes 391 00:23:38,931 --> 00:23:41,586 may help answer a critical question. 392 00:23:41,689 --> 00:23:44,482 What was the relative angle between the two aircraft 393 00:23:44,586 --> 00:23:47,896 at the time of the... their contact? 394 00:23:53,275 --> 00:23:56,827 Most of the pieces from the two planes are kilometres apart. 395 00:23:56,931 --> 00:23:58,551 But a large section of the tail 396 00:23:58,655 --> 00:24:02,000 from the Saudi aircraft is found near the beginning of the debris field. 397 00:24:07,586 --> 00:24:10,793 This suggests it was one of the first pieces to come off that plane. 398 00:24:21,793 --> 00:24:23,862 The significant point of contact 399 00:24:23,965 --> 00:24:27,103 in this particular accident in the air, was between 400 00:24:27,206 --> 00:24:32,413 the tail end of the IL-76, 401 00:24:32,517 --> 00:24:36,931 and the wing portion of 402 00:24:38,103 --> 00:24:43,620 the Boeing 747 of Saudi Air. 403 00:24:43,724 --> 00:24:46,551 The tail of the Kazakh plane appears to have pierced 404 00:24:46,655 --> 00:24:48,931 through the left wing of the Saudi jet. 405 00:24:49,034 --> 00:24:51,241 If that's the case, the Kazakh flight 406 00:24:51,344 --> 00:24:53,793 hadn't been above the Saudi jet when they collided 407 00:24:53,896 --> 00:24:55,482 as air traffic controllers thought. 408 00:24:56,724 --> 00:24:58,758 It must have been below it. 409 00:25:02,000 --> 00:25:04,275 It's a puzzling discovery that adds to the mystery. 410 00:25:06,241 --> 00:25:07,862 Investigators still don't know 411 00:25:07,965 --> 00:25:09,965 which plane was in the wrong airspace. 412 00:25:12,724 --> 00:25:15,448 What they do know is that once the two planes hit, 413 00:25:15,551 --> 00:25:17,275 there was no hope for either crew. 414 00:25:19,137 --> 00:25:21,413 After hitting the other plane's wing, 415 00:25:21,517 --> 00:25:23,655 the Kazakh plane's tail tore through 416 00:25:23,758 --> 00:25:26,965 the horizontal stabilizer at the rear of the Saudi 747. 417 00:25:28,275 --> 00:25:30,517 Five-and-a-half meters of it is torn off. 418 00:25:30,620 --> 00:25:33,827 Without it, the Saudi crew can't control their plane. 419 00:25:35,551 --> 00:25:40,862 The result is, the aircraft goes into uncontrollable spiral. 420 00:25:40,965 --> 00:25:43,689 And in this particular case, 421 00:25:43,793 --> 00:25:48,310 I would say, both aircraft had gone into that situation. 422 00:25:53,517 --> 00:25:55,689 What they've found in the wreckage of the two jets 423 00:25:55,793 --> 00:25:57,137 frustrates the investigators. 424 00:25:58,862 --> 00:26:01,517 They now understand how the planes collided, 425 00:26:01,620 --> 00:26:04,586 but they still don't know why they were at the same altitude, 426 00:26:04,689 --> 00:26:08,310 or in fact, what altitude they collided at. 427 00:26:08,413 --> 00:26:12,551 How had the Kazakh jet, which was supposed to be above the Saudi flight, 428 00:26:12,655 --> 00:26:14,206 ended up below it? 429 00:26:17,413 --> 00:26:19,586 Almost two weeks after the accident, 430 00:26:19,689 --> 00:26:23,413 Captain Ashok Verma joins investigators at the scene. 431 00:26:23,517 --> 00:26:27,206 By that time, the operations for digging 432 00:26:27,310 --> 00:26:30,689 the Saudi Air cockpit had been completed. 433 00:26:32,448 --> 00:26:38,310 Whatever equipment was recoverable had been recovered. 434 00:26:38,413 --> 00:26:41,172 Like the rest of the evidence uncovered so far, 435 00:26:41,275 --> 00:26:43,068 the instruments from the Saudi plane 436 00:26:43,172 --> 00:26:45,172 don't help explain what happened. 437 00:26:45,275 --> 00:26:48,620 The force of the crash has completely destroyed them. 438 00:26:48,724 --> 00:26:52,068 I can't find anything. Too much damage. 439 00:26:52,172 --> 00:26:54,793 I agree. Look at this. 440 00:26:54,896 --> 00:26:58,137 We could hardly find any useful material. 441 00:26:58,241 --> 00:27:00,965 With the disappointing discovery, 442 00:27:01,068 --> 00:27:03,310 the investigators are forced to move on. 443 00:27:06,482 --> 00:27:09,068 They've learned all they can at the crash site. 444 00:27:09,172 --> 00:27:12,724 The case now depends on what they can find out from the black boxes. 445 00:27:16,068 --> 00:27:18,965 Investigators hope that somewhere on the cockpit recordings, 446 00:27:19,068 --> 00:27:22,103 or buried in the flight data, are the clues they need. 447 00:27:23,862 --> 00:27:26,034 Where were the planes when they collided? 448 00:27:26,137 --> 00:27:29,241 And how had they ended up on a deadly collision course. 449 00:27:29,344 --> 00:27:31,517 Get to the 150, because at the 140... 450 00:27:40,379 --> 00:27:41,689 It's been three months since 451 00:27:41,793 --> 00:27:44,758 the mid-air collision of two passenger jets near New Delhi. 452 00:27:50,896 --> 00:27:54,517 Investigators have been frustrated by a lack of conclusive evidence. 453 00:27:56,793 --> 00:28:00,172 They hope the planes' black boxes will help them solve the case. 454 00:28:01,413 --> 00:28:04,137 In order to avoid any suggestion of bias, 455 00:28:04,241 --> 00:28:08,068 the boxes from the Saudi flight are being analyzed in England. 456 00:28:08,172 --> 00:28:10,862 Technicians from the Air Accidents Investigation Branch 457 00:28:10,965 --> 00:28:12,724 try to extract valuable data. 458 00:28:15,137 --> 00:28:19,482 The neutrality of state where the recorders are handled 459 00:28:19,586 --> 00:28:22,241 was an essential thing. 460 00:28:22,344 --> 00:28:25,482 Each plane was equipped with two black boxes, 461 00:28:25,586 --> 00:28:29,586 a flight data recorder, and a cockpit voice recorder. 462 00:28:29,689 --> 00:28:31,896 The flight data recorder contains information 463 00:28:32,000 --> 00:28:34,862 on dozens of aspects of a plane's performance. 464 00:28:34,965 --> 00:28:37,620 Among them, the altitude, the airspeed, 465 00:28:37,724 --> 00:28:40,103 and the changes pilots make to the flight controls. 466 00:28:46,379 --> 00:28:49,689 The cockpit voice recorder picks up all the conversations in the cockpit. 467 00:28:52,137 --> 00:28:53,379 279, Good day. 468 00:28:56,517 --> 00:29:00,413 As investigators try to learn more about the collision near New Delhi, 469 00:29:00,517 --> 00:29:03,000 they use the information stored on the black boxes 470 00:29:03,103 --> 00:29:04,655 to make a chronology of events. 471 00:29:07,000 --> 00:29:09,275 Peter Sheppard is head of the recorder section 472 00:29:09,379 --> 00:29:11,793 of the Air Accidents Investigation Branch. 473 00:29:13,413 --> 00:29:17,000 He'll work backwards from the moment of impact. 474 00:29:17,103 --> 00:29:19,551 The point of the collision is reasonably well defined 475 00:29:19,655 --> 00:29:23,379 by rapid changes in parameters on each, each aircraft. 476 00:29:23,482 --> 00:29:26,241 If we make that our time zero point, 477 00:29:26,344 --> 00:29:28,724 we can then relate that to individual times, 478 00:29:28,827 --> 00:29:31,275 and then build up, you know, a common time base. 479 00:29:33,724 --> 00:29:37,482 First, Sheppard and his team concentrate on the Saudi 747. 480 00:29:37,586 --> 00:29:40,931 Saudi 763 approaching 140 for higher. 481 00:29:42,758 --> 00:29:45,103 Roger, maintain flight level 140. 482 00:29:45,206 --> 00:29:46,206 Standby for higher. 483 00:29:47,862 --> 00:29:51,034 Saudi 763, will maintain 140. 484 00:29:51,137 --> 00:29:53,793 The CVR reveals that the Saudi pilots received 485 00:29:53,896 --> 00:29:56,275 clear instructions about their altitude, 486 00:29:56,379 --> 00:29:57,758 and seem to have understood them. 487 00:29:59,103 --> 00:30:02,172 After being told to hold at 14,000 feet, 488 00:30:02,275 --> 00:30:05,482 there was no discussion of climbing to a higher altitude, 489 00:30:05,586 --> 00:30:08,344 which would have taken them into the path of the Kazakh flight. 490 00:30:10,931 --> 00:30:13,413 Next, Sheppard looks at the flight data recorder 491 00:30:13,517 --> 00:30:15,689 to confirm that the Saudi flight actually 492 00:30:15,793 --> 00:30:17,413 followed the instructions it was given. 493 00:30:19,655 --> 00:30:22,896 The recorder from the Saudi flight told us that 494 00:30:23,000 --> 00:30:25,724 the altitude had been normal during climb out 495 00:30:27,241 --> 00:30:31,034 The Saudi pilots leveled off at 14,108 feet. 496 00:30:31,137 --> 00:30:32,551 Well within their safe corridor. 497 00:30:34,448 --> 00:30:37,000 It had leveled at its assigned altitude, 498 00:30:37,103 --> 00:30:39,241 of, um, 14,000 feet, 499 00:30:39,344 --> 00:30:42,000 and continued to fly level. 500 00:30:42,103 --> 00:30:45,758 The Saudi pilots followed 501 00:30:45,862 --> 00:30:49,413 the ATC instructions meticulously, 502 00:30:49,517 --> 00:30:55,137 which is borne out by their confirmatory calls back to the ATC. 503 00:30:55,241 --> 00:30:57,827 Air traffic controllers wanted the two planes separated 504 00:30:57,931 --> 00:30:59,517 by 1,000 feet, 505 00:30:59,620 --> 00:31:03,413 and wanted the Saudi plane to fly below the Kazakh jet. 506 00:31:03,517 --> 00:31:06,034 If the Saudi pilots did nothing unusual, 507 00:31:06,137 --> 00:31:08,034 suspicion is growing that somehow, 508 00:31:08,137 --> 00:31:10,448 it was the Kazakh plane that was in the wrong place. 509 00:31:14,482 --> 00:31:17,137 Alarmingly, when investigators examine the information 510 00:31:17,241 --> 00:31:19,586 from the Kazakh jet's flight data recorder, 511 00:31:20,793 --> 00:31:22,827 they discover that it descended far below 512 00:31:22,931 --> 00:31:25,344 the 15,000 feet it was supposed to stay at. 513 00:31:29,206 --> 00:31:30,965 Moments before the collision, 514 00:31:31,068 --> 00:31:34,689 the Kazakh plane is at 14,100 feet. 515 00:31:34,793 --> 00:31:38,172 Almost 1,000 feet lower than its assigned altitude, 516 00:31:38,275 --> 00:31:41,310 and less than ten feet below the Saudi flight. 517 00:31:43,275 --> 00:31:46,000 It then powered directly into the Saudi jet. 518 00:31:49,275 --> 00:31:53,931 The Kazakh crew had not stopped descending 519 00:31:54,034 --> 00:31:56,310 at the altitude they were cleared to. 520 00:31:56,413 --> 00:31:57,689 That was 15,000 feet. 521 00:32:00,448 --> 00:32:03,758 But why had the Kazakh flight dropped so badly off course? 522 00:32:05,310 --> 00:32:07,068 Kazakh 1907, report position. 523 00:32:08,931 --> 00:32:11,448 Kazakhstan Airlines presents one theory 524 00:32:11,551 --> 00:32:14,137 for their plane's dramatic loss of altitude. 525 00:32:14,241 --> 00:32:20,689 The Kazakhstan defense mainly relied on presence of turbulence. 526 00:32:20,793 --> 00:32:23,965 Perhaps a sudden burst of turbulence had forced the plane lower. 527 00:32:25,724 --> 00:32:27,517 The data recorder of the Kazakh flight 528 00:32:27,620 --> 00:32:30,931 does seem to indicate that the crew had a bumpy ride. 529 00:32:31,034 --> 00:32:34,724 It shows two distinct and sudden drops of more than 400 feet. 530 00:32:36,586 --> 00:32:39,689 The airline claims both of these drops were caused by turbulence. 531 00:32:42,137 --> 00:32:44,206 But Peter Sheppard isn't so sure. 532 00:32:45,758 --> 00:32:50,206 When we saw the jumps of 250-500 feet, 533 00:32:50,310 --> 00:32:54,034 our initial response was that these can't be right. 534 00:32:54,137 --> 00:32:56,758 I mean, you know, it... it was... 535 00:32:56,862 --> 00:32:58,689 the rate at which they changed was beyond that, 536 00:32:58,793 --> 00:33:01,379 that an aircraft can actually perform. 537 00:33:03,413 --> 00:33:06,620 What else could cause the plane to drop so quickly? 538 00:33:06,724 --> 00:33:08,620 Or at least seem to drop so quickly? 539 00:33:09,862 --> 00:33:11,586 Sheppard searches for an explanation. 540 00:33:13,241 --> 00:33:14,827 We tried to resolve the inaccuracies 541 00:33:14,931 --> 00:33:17,758 in the Kazakh recording by looking at the other 542 00:33:17,862 --> 00:33:20,068 parameters that were recorded 543 00:33:20,172 --> 00:33:22,689 and trying to derive altitude, um... 544 00:33:22,793 --> 00:33:24,068 using these other recordings. 545 00:33:25,965 --> 00:33:29,206 It's intricate math. By using information 546 00:33:29,310 --> 00:33:33,275 including the speed and rate of descent from the flight data recorder, 547 00:33:33,379 --> 00:33:36,482 Sheppard determines that the plane was on a steady downward approach. 548 00:33:40,137 --> 00:33:43,137 The reason for the apparent sharp drops is simple. 549 00:33:43,241 --> 00:33:46,379 Sheppard learns that the sensor that sends altitude information 550 00:33:46,482 --> 00:33:48,965 to the flight data recorder was faulty. 551 00:33:49,068 --> 00:33:52,793 It would stick, and temporarily stop sending information. 552 00:33:52,896 --> 00:33:55,310 When it got unstuck, it would wrongly appear 553 00:33:55,413 --> 00:33:57,655 as though the plane had lost considerable altitude. 554 00:33:59,655 --> 00:34:02,896 It's as if there was bit of glue on one area and it stuck in that. 555 00:34:04,172 --> 00:34:06,862 And eventually... 556 00:34:06,965 --> 00:34:08,275 the altitude changed so much 557 00:34:08,379 --> 00:34:10,655 that the force on it made it jump... 558 00:34:10,758 --> 00:34:12,517 again and it stuck there for a little while. 559 00:34:14,758 --> 00:34:17,310 Investigators can now conclusively dismiss 560 00:34:17,413 --> 00:34:19,172 turbulence as a factor in the collision. 561 00:34:20,551 --> 00:34:21,896 So there's no sudden descent? 562 00:34:24,000 --> 00:34:25,482 Scanning maintenance records, 563 00:34:25,586 --> 00:34:28,206 investigators also discover that there was no problem 564 00:34:28,310 --> 00:34:30,034 with the Kazakh plane's altimeters. 565 00:34:31,931 --> 00:34:33,724 They conclude that the difference found 566 00:34:33,827 --> 00:34:36,758 in the cockpit instruments was a result of the crash, 567 00:34:36,862 --> 00:34:38,034 it didn't cause it. 568 00:34:41,413 --> 00:34:44,103 To understand why the Kazakh plane kept descending 569 00:34:44,206 --> 00:34:45,862 after it was told to hold, 570 00:34:45,965 --> 00:34:48,482 investigators turn to the cockpit voice recorder. 571 00:34:50,448 --> 00:34:53,000 It begins long before the crash itself. 572 00:34:53,103 --> 00:34:55,931 Initially, there are no hints that anything is wrong. 573 00:34:57,655 --> 00:35:02,000 Kazakh 1907, report level passing. 574 00:35:03,931 --> 00:35:05,344 Passing 240, 575 00:35:05,448 --> 00:35:07,172 Kazakh 1907. 576 00:35:07,275 --> 00:35:10,758 Because the Ilyushin 76 is a modified military plane, 577 00:35:10,862 --> 00:35:12,827 it has another unusual feature. 578 00:35:12,931 --> 00:35:15,758 A position for a radio operator in the cockpit. 579 00:35:15,862 --> 00:35:17,862 Egor Repp mans that position, 580 00:35:17,965 --> 00:35:20,965 and handles all communications for the Kazakh flight. 581 00:35:21,068 --> 00:35:25,586 Roger, over to Delhi Approach 127 decimal 9. 582 00:35:25,689 --> 00:35:30,724 127 decimal 9. Bye bye, Kazakh 1907. 583 00:35:30,827 --> 00:35:32,862 As the aircraft nears the airport, 584 00:35:32,965 --> 00:35:35,551 Repp gets in touch with Approach Controller Dutta. 585 00:35:37,862 --> 00:35:40,827 Delhi Approach. Good Evening. Kazakh 1907, 586 00:35:40,931 --> 00:35:43,758 passing 230 to 180. 587 00:35:45,310 --> 00:35:48,103 I told Kazakh to descend, 588 00:35:48,206 --> 00:35:50,758 and maintain flight level 150, 589 00:35:50,862 --> 00:35:52,034 that is 15,000 feet. 590 00:35:52,827 --> 00:35:55,000 Roger Kazakh 1907, 591 00:35:55,103 --> 00:35:58,379 descend flight level 150, report reaching. 592 00:36:00,310 --> 00:36:05,034 One thousand feet vertical separation is sufficient, 593 00:36:05,137 --> 00:36:09,172 and that was granted to the two aircraft. 594 00:36:09,275 --> 00:36:13,655 Kazakh 1907 now reached 150. 595 00:36:13,758 --> 00:36:17,551 The Kazakhstan radio operator had... 596 00:36:17,655 --> 00:36:22,137 at one time stated reaching flight level 150. 597 00:36:22,241 --> 00:36:24,655 It's just one minute before the impact. 598 00:36:26,034 --> 00:36:27,896 And at this point the Kazakh plane appears 599 00:36:28,000 --> 00:36:30,413 to be right where it's supposed to be, 600 00:36:30,517 --> 00:36:33,000 one thousand feet higher than the Saudi plane. 601 00:36:34,724 --> 00:36:37,551 But investigators know that instead of levelling off, 602 00:36:37,655 --> 00:36:39,344 the plane continued to descend. 603 00:36:40,448 --> 00:36:41,827 This is where the trouble starts. 604 00:36:43,655 --> 00:36:46,310 As investigators compare the flight data information 605 00:36:46,413 --> 00:36:49,172 to the cockpit voice, they notice something disturbing. 606 00:36:50,413 --> 00:36:53,965 Kazakh 1907 now reached 150. 607 00:36:55,862 --> 00:36:58,827 When Repp calls out that they've descended to 15,000 feet, 608 00:36:58,931 --> 00:37:02,448 he's actually over 1,000 feet higher than he thinks he is. 609 00:37:08,310 --> 00:37:12,241 Investigators wonder how he could make such an enormous mistake. 610 00:37:12,344 --> 00:37:15,206 Why would he say he was at 15,000 feet 611 00:37:15,310 --> 00:37:18,068 when in fact he was at 16,000? 612 00:37:18,172 --> 00:37:21,793 They consider the layout of the cockpit. 613 00:37:21,896 --> 00:37:26,344 A radio operator does not have his independent altimeter. 614 00:37:26,448 --> 00:37:29,689 There are two metric altimeters fitted in front of, 615 00:37:29,793 --> 00:37:33,379 uh, one each in front of the pilots, 616 00:37:33,482 --> 00:37:35,482 with some effort 617 00:37:35,586 --> 00:37:38,827 the radio operator could also see this. 618 00:37:39,896 --> 00:37:41,000 Whatever the reason, 619 00:37:41,103 --> 00:37:43,310 Repp is mistaken about his plane's height. 620 00:37:43,413 --> 00:37:45,689 And he's the only one in contact with the ground. 621 00:37:47,758 --> 00:37:50,655 Despite being told to remain at 15,000 feet, 622 00:37:50,758 --> 00:37:52,896 the plane continues to descend. 623 00:37:53,000 --> 00:37:56,206 As it does, Dutta issues a warning to the Kazakh pilots. 624 00:37:56,310 --> 00:37:58,551 Identified traffic 12 o'clock reciprocal, 625 00:37:58,655 --> 00:38:02,413 Saudi Boeing 747 and ten miles. 626 00:38:02,517 --> 00:38:04,551 Likely to cross in another five miles. 627 00:38:04,655 --> 00:38:06,862 Report if in sight. 628 00:38:06,965 --> 00:38:09,827 He tells them to watch out for the Saudi flight. 629 00:38:09,931 --> 00:38:12,137 But the Kazakh jet just keeps flying lower. 630 00:38:13,103 --> 00:38:14,275 Ahead? 631 00:38:14,379 --> 00:38:15,586 Ahead! 632 00:38:17,620 --> 00:38:20,344 Just before the crash, Egor Repp seems to have 633 00:38:20,448 --> 00:38:23,862 recognized that the plane is now flying dangerously low. 634 00:38:23,965 --> 00:38:26,965 But his warning doesn't come in time. 635 00:38:27,068 --> 00:38:29,206 Keep the 150! Do not descend! 636 00:38:29,310 --> 00:38:30,379 Accelerate Sanya! 637 00:38:32,965 --> 00:38:34,379 The cockpit voice recorder 638 00:38:34,482 --> 00:38:37,931 proves what investigators found in the flight data. 639 00:38:38,034 --> 00:38:40,827 At the time of the crash, the Kazakh jet was trying 640 00:38:40,931 --> 00:38:42,793 desperately to get back on course. 641 00:38:45,586 --> 00:38:46,965 Get to the 150, 642 00:38:47,068 --> 00:38:49,103 because on the 140... 643 00:38:52,620 --> 00:38:54,827 But investigators are still puzzled. 644 00:38:54,931 --> 00:38:57,034 Why had the Kazakh plane kept descending? 645 00:38:58,827 --> 00:39:02,448 After ruling out, uh, controller's error, 646 00:39:02,551 --> 00:39:04,655 ruling out mechanical failure, 647 00:39:04,758 --> 00:39:08,827 you have to go further into the details of human behavior 648 00:39:08,931 --> 00:39:12,000 during the operation of a flight. 649 00:39:12,103 --> 00:39:15,137 Kazakhstan is one of several now independent republics 650 00:39:15,241 --> 00:39:18,620 that used to be part of the Soviet Union. 651 00:39:18,724 --> 00:39:22,172 The national airline has a reputation at Indira Gandhi Airport. 652 00:39:23,413 --> 00:39:25,275 There was always a sense that, you know, 653 00:39:25,379 --> 00:39:27,517 these were small fly by night operators 654 00:39:27,620 --> 00:39:29,655 essentially doing the charter business, 655 00:39:29,758 --> 00:39:32,103 and they didn't necessarily follow the conventions 656 00:39:32,206 --> 00:39:34,655 of modern Western aviation. 657 00:39:34,758 --> 00:39:38,965 We examined the background of their knowledge of English language. 658 00:39:39,068 --> 00:39:43,068 The crew in the Soviet states... 659 00:39:43,172 --> 00:39:47,241 uh, they passed English examination, 660 00:39:47,344 --> 00:39:51,206 but they're not fluent in spoken English. 661 00:39:51,310 --> 00:39:55,241 Verma now listens more closely to the cockpit voice recorder, 662 00:39:55,344 --> 00:39:59,241 looking for an indication that the crew misunderstood their instructions. 663 00:39:59,344 --> 00:40:01,517 Had a language barrier caused the crash? 664 00:40:02,517 --> 00:40:03,655 How many miles? 665 00:40:05,068 --> 00:40:10,379 Traffic is at eight miles level 140. 666 00:40:10,482 --> 00:40:15,413 Did the Kazakh pilots confuse their own altitude 667 00:40:15,517 --> 00:40:19,689 with that allocated to the Saudi aircraft? 668 00:40:20,689 --> 00:40:21,551 Report eight miles. 669 00:40:23,137 --> 00:40:25,068 Verma finds that members of this crew 670 00:40:25,172 --> 00:40:27,793 weren't communicating clearly with each other. 671 00:40:27,896 --> 00:40:31,137 Egor Repp was responsible for communication with the ground, 672 00:40:31,241 --> 00:40:33,448 but there's no indication that the pilot and co-pilot 673 00:40:33,551 --> 00:40:35,275 were listening to his instructions. 674 00:40:37,172 --> 00:40:39,655 Switch on the engine inlet heating. 675 00:40:39,758 --> 00:40:43,241 While the rest of the crew was busy discussing arrival procedures, 676 00:40:43,344 --> 00:40:46,137 Repp alone seemed to be occupied with their altitude. 677 00:40:47,172 --> 00:40:50,137 Now looking 1907. 678 00:40:50,241 --> 00:40:53,655 It is a usual practice that... 679 00:40:53,758 --> 00:40:55,482 the briefing for the arrival 680 00:40:55,586 --> 00:40:58,241 is completed before the start of descent... 681 00:40:58,344 --> 00:41:02,793 so that all crew can pay full attention to the radio. 682 00:41:02,896 --> 00:41:05,310 While the radio operator appears to have understood 683 00:41:05,413 --> 00:41:08,241 that the Saudi plane was at 14,000 feet, 684 00:41:08,344 --> 00:41:10,448 investigators believe the co-pilot thought that 685 00:41:10,551 --> 00:41:12,724 he was cleared to 14,000 feet, 686 00:41:12,827 --> 00:41:13,862 and continued his descent. 687 00:41:17,172 --> 00:41:18,137 Hold the level! 688 00:41:18,241 --> 00:41:20,241 What level were we given? 689 00:41:20,344 --> 00:41:23,931 When the pilot does respond, he seems confused. 690 00:41:24,034 --> 00:41:30,000 I think, pilots did not pay that much attention, 691 00:41:30,103 --> 00:41:33,206 and relied too much on the radio operator 692 00:41:33,310 --> 00:41:37,517 to navigate the aircraft during this critical phase. 693 00:41:37,620 --> 00:41:39,551 The decision to increase power 694 00:41:39,655 --> 00:41:41,413 and stop descending ends in tragedy. 695 00:41:41,517 --> 00:41:43,655 Keep the 150! Do not descend! 696 00:41:43,758 --> 00:41:44,862 Accelerate Sanya! 697 00:41:45,586 --> 00:41:46,862 Get to the 150, 698 00:41:46,965 --> 00:41:48,931 because on the 140... 699 00:42:00,793 --> 00:42:03,206 The final report points a finger squarely 700 00:42:03,310 --> 00:42:05,172 at the crew of the Kazakh plane. 701 00:42:05,275 --> 00:42:08,482 In the wrong place at the wrong time, 702 00:42:08,586 --> 00:42:13,000 a simple misunderstanding led to the deaths of 349 people. 703 00:42:15,724 --> 00:42:18,724 The investigation concluded 704 00:42:18,827 --> 00:42:23,206 that the primary cause of this midair collision 705 00:42:23,310 --> 00:42:28,827 was non-adherence to the authorized altitude 706 00:42:28,931 --> 00:42:32,655 allocated to the Kazakhstan aircraft. 707 00:42:32,758 --> 00:42:35,413 Investigators are confident they know what caused 708 00:42:35,517 --> 00:42:38,034 the worst mid-air collision in aviation history. 709 00:42:38,137 --> 00:42:40,206 But there are steps they want the industry 710 00:42:40,310 --> 00:42:43,137 to take to help make Indira Gandhi airport safer. 711 00:42:44,793 --> 00:42:47,000 What they find is that the technology 712 00:42:47,103 --> 00:42:51,034 that could have prevented this accident was already at the airport. 713 00:42:52,965 --> 00:42:54,000 Saudi 763. 714 00:42:56,344 --> 00:42:59,551 Investigators have determined that poor cockpit communication 715 00:42:59,655 --> 00:43:02,931 and a simple misunderstanding caused a devastating accident 716 00:43:03,034 --> 00:43:05,034 which killed almost 350 people. 717 00:43:14,793 --> 00:43:18,620 But technology existed that could have helped avoid this accident, 718 00:43:18,724 --> 00:43:21,931 systems that would have helped both the pilots in the air, 719 00:43:22,034 --> 00:43:23,931 and the controllers on the ground. 720 00:43:24,034 --> 00:43:27,000 Investigators are especially critical of the radar 721 00:43:27,103 --> 00:43:28,724 that was being used in New Delhi. 722 00:43:29,862 --> 00:43:32,551 Air traffic controllers did rely 723 00:43:32,655 --> 00:43:35,068 on fairly outdated technology at that stage. 724 00:43:35,172 --> 00:43:38,241 Um, there wasn't any secondary radar available 725 00:43:38,344 --> 00:43:40,344 at Delhi airport there was only an old primary radar. 726 00:43:41,965 --> 00:43:44,517 Primary radar sends out radio signals 727 00:43:44,620 --> 00:43:46,724 to locate airplanes in the sky. 728 00:43:46,827 --> 00:43:50,068 The signal bounces off the plane and back to a dish on the ground. 729 00:43:51,896 --> 00:43:54,689 It reads a plane's position, but not its altitude. 730 00:43:56,620 --> 00:43:59,000 The primary radar gives you 2D picture. 731 00:44:00,862 --> 00:44:03,448 Secondary radar works differently. 732 00:44:03,551 --> 00:44:06,655 A transponder aboard an aircraft sends a message 733 00:44:06,758 --> 00:44:08,655 to the ground with key information 734 00:44:08,758 --> 00:44:10,689 about the flight, including its altitude. 735 00:44:12,344 --> 00:44:15,931 Saudi 763, approaching flight level 1-0-0. 736 00:44:17,689 --> 00:44:21,275 Roger. Climb to flight level 140. 737 00:44:23,413 --> 00:44:24,896 On the day of the collision, 738 00:44:25,000 --> 00:44:27,586 Approach Controller VK Dutta could only rely on 739 00:44:27,689 --> 00:44:30,482 what the crews told him about their aircraft's altitudes. 740 00:44:31,689 --> 00:44:35,137 Kazakh 1907, now reached 150. 741 00:44:36,275 --> 00:44:38,034 The Kazakh Radio Operator said 742 00:44:38,137 --> 00:44:40,655 that they were flying at 15,000 feet. 743 00:44:40,758 --> 00:44:43,000 But Dutta had no way to confirm that. 744 00:44:44,896 --> 00:44:48,000 If he had known the Kazakh flight's actual altitude, 745 00:44:48,103 --> 00:44:50,965 he could have diverted the Saudi flight from its path. 746 00:45:06,586 --> 00:45:08,000 That is the a 3D picture. 747 00:45:08,103 --> 00:45:12,620 So you can, you have some, some time to react to it. 748 00:45:12,724 --> 00:45:13,827 You can take the aircraft away. 749 00:45:15,379 --> 00:45:16,965 At the time of the accident, 750 00:45:17,068 --> 00:45:20,241 India had ordered a $118 million 751 00:45:20,344 --> 00:45:22,827 air traffic control system with secondary radar, 752 00:45:22,931 --> 00:45:25,241 and more sophisticated communications 753 00:45:25,344 --> 00:45:26,827 and navigational equipment. 754 00:45:28,413 --> 00:45:30,862 The system had originally been scheduled to be installed 755 00:45:30,965 --> 00:45:32,827 two weeks before the accident. 756 00:45:34,655 --> 00:45:36,551 But on the day of the crash, 757 00:45:36,655 --> 00:45:38,689 the system hadn't even been unpacked. 758 00:45:40,827 --> 00:45:44,275 Secondary radar is an advancement on the primary radar. 759 00:45:44,379 --> 00:45:46,137 And in this particular case, 760 00:45:46,241 --> 00:45:51,068 also by getting the altitude information 761 00:45:51,172 --> 00:45:54,931 it could have been possible that the accident 762 00:45:55,034 --> 00:45:56,758 of this nature could have been avoided. 763 00:45:58,689 --> 00:46:00,931 In the year following the accidents, 764 00:46:01,034 --> 00:46:02,448 there would be three near misses 765 00:46:02,551 --> 00:46:03,896 near Indira Gandhi airport. 766 00:46:05,827 --> 00:46:10,000 It would take more than two years for the secondary radar system to be installed. 767 00:46:13,413 --> 00:46:17,517 Today, controllers at Indira Gandhi International Airport 768 00:46:17,620 --> 00:46:20,931 see an airplane's flight number, altitude and heading. 769 00:46:22,965 --> 00:46:25,965 It's far more information than controller VK Dutta 770 00:46:26,068 --> 00:46:28,103 had available to him on the day of the accident. 771 00:46:31,448 --> 00:46:33,931 Experts believe another piece of technology 772 00:46:34,034 --> 00:46:36,724 could have helped prevent the collision, TCAS. 773 00:46:38,344 --> 00:46:44,103 TCAS equipment generates cautions and warnings for the crew. 774 00:46:45,793 --> 00:46:49,793 It allows them time to react, 775 00:46:49,896 --> 00:46:54,689 draws their attention to the situation around 776 00:46:54,793 --> 00:46:58,896 and it, uh, looks into vertical separation. 777 00:47:00,310 --> 00:47:02,586 TCAS is a collision avoidance system 778 00:47:02,689 --> 00:47:05,448 that can be installed on board airliners. 779 00:47:05,551 --> 00:47:09,034 In many countries, the technology is mandatory. 780 00:47:09,137 --> 00:47:12,965 It alerts pilots when other flights are coming too close. 781 00:47:13,068 --> 00:47:16,965 The system also automatically tells them what evasive action they should take. 782 00:47:18,827 --> 00:47:20,965 Neither plane was equipped with TCAS. 783 00:47:23,275 --> 00:47:26,448 The Indian Airports Authority has also made the airport safer 784 00:47:26,551 --> 00:47:30,379 by re-designing the air corridors coming and going from the runways. 785 00:47:32,517 --> 00:47:35,068 At the time of the collision, there was one main 786 00:47:35,172 --> 00:47:36,931 air corridor for commercial planes 787 00:47:37,034 --> 00:47:40,655 landing and taking off from Indira Gandhi International Airport. 788 00:47:40,758 --> 00:47:42,689 With the increase in air traffic, 789 00:47:42,793 --> 00:47:44,965 that single corridor was becoming too crowded. 790 00:47:49,379 --> 00:47:51,068 In the wake of the accident, 791 00:47:51,172 --> 00:47:53,862 more air corridors were opened for commercial flights. 792 00:47:56,517 --> 00:48:01,206 In general, aviation safety standards has improved. 793 00:48:01,310 --> 00:48:03,689 The concern for the safety has improved. 794 00:48:05,655 --> 00:48:09,172 Out of date technology and poor communication led to this crash. 795 00:48:12,517 --> 00:48:14,724 But like almost every aviation accident, 796 00:48:14,827 --> 00:48:17,068 it was a chain of seemingly minor events 797 00:48:17,172 --> 00:48:18,827 that ended in disaster. 798 00:48:22,137 --> 00:48:23,034 In retrospect... 799 00:48:25,275 --> 00:48:27,103 those were some very unlucky people 800 00:48:27,206 --> 00:48:28,620 to meet in the sky that night. 801 00:48:30,275 --> 00:48:32,103 You know, it's a... it's a one in a million chance 802 00:48:33,206 --> 00:48:34,931 for that to happen. Uh... 803 00:48:35,034 --> 00:48:38,034 Certainly there were other things that could have helped. 804 00:48:38,137 --> 00:48:42,172 Radar, uh, collision avoidance systems... 805 00:48:42,275 --> 00:48:46,344 And I... And I think we continue to make advances there. 806 00:48:46,448 --> 00:48:48,931 I... I don't worry about flying. 807 00:48:50,103 --> 00:48:54,655 Um, certainly... you know, destiny, 808 00:48:54,758 --> 00:48:58,068 I don't know. It was... glad we weren't five minutes 809 00:48:58,172 --> 00:49:00,000 in front of where we were at, that's for sure. 810 00:49:02,000 --> 00:49:06,586 VK Dutta went on to have a long career as an air traffic controller. 811 00:49:06,689 --> 00:49:10,103 Today, he works at a college, training young controllers. 812 00:49:12,310 --> 00:49:15,724 So I'm chief instructor there, so I'm training ATC's. 813 00:49:15,827 --> 00:49:18,896 I'm addicted to my job. I love it. I really love it. 814 00:49:20,965 --> 00:49:22,206 Dutta, who was initially 815 00:49:22,310 --> 00:49:24,586 suspected of having caused the crash, 816 00:49:24,689 --> 00:49:27,758 helped implement the changes to make New Delhi's airport safer. 817 00:49:29,103 --> 00:49:30,793 His efforts have paid off. 818 00:49:30,896 --> 00:49:34,551 The airport now handles 20 million passengers a year. 819 00:49:34,655 --> 00:49:37,137 Since the new radar system was installed, 820 00:49:37,241 --> 00:49:39,137 and the new corridors opened, 821 00:49:39,241 --> 00:49:41,793 there hasn't been a fatal accident at this airport.