1 00:00:02,655 --> 00:00:04,724 Alpha Lima Whiskey, 301 Santo Domingo, come in. 2 00:00:04,827 --> 00:00:07,689 A Boeing 757 disappears from radar 3 00:00:07,793 --> 00:00:10,379 with 189 people on board. 4 00:00:11,793 --> 00:00:14,758 The plane's wreckage is soon found at sea. 5 00:00:14,862 --> 00:00:17,000 There are no survivors to say what happened. 6 00:00:18,689 --> 00:00:25,482 This accident was the first major loss of a Boeing 757 aircraft. 7 00:00:25,586 --> 00:00:28,068 Investigators find no clues in the wreckage. 8 00:00:30,758 --> 00:00:33,241 Only the plane's black box can tell them what happened. 9 00:00:34,482 --> 00:00:37,482 The tape raises a perplexing question. 10 00:00:37,586 --> 00:00:40,000 310, Santo Domingo, come in, please. 11 00:00:40,103 --> 00:00:41,896 My airspeed indicator is not working. 12 00:00:42,000 --> 00:00:43,517 What's happening? 13 00:00:43,620 --> 00:00:46,586 How had the failure of one single instrument... 14 00:00:46,689 --> 00:00:48,862 Sir, pull up! 15 00:00:48,965 --> 00:00:52,482 ...caused the crash of one of the world's most sophisticated jetliners? 16 00:00:57,275 --> 00:00:58,586 Mayday! Mayday! 17 00:01:22,655 --> 00:01:27,586 Gregorio Luperon International Airport in Puerto Plata, the Dominican Republic. 18 00:01:28,827 --> 00:01:30,931 February the 6th, 1996. 19 00:01:33,448 --> 00:01:36,310 The small Caribbean island is a popular winter getaway. 20 00:01:39,965 --> 00:01:43,034 A group of German tourists has been delayed. 21 00:01:43,137 --> 00:01:46,862 There are mechanical problems with the jet that was supposed to take them back to Frankfurt. 22 00:01:49,172 --> 00:01:53,379 The airline has arranged to lease another plane for the flight. 23 00:01:53,482 --> 00:01:58,103 The replacement jet is owned by Turkish Charter Company Birgenair. 24 00:01:58,206 --> 00:02:02,241 They have a 757 that's been sitting on the tarmac for almost three weeks. 25 00:02:03,862 --> 00:02:07,551 But it takes several hours to get the plane ready to go... 26 00:02:07,655 --> 00:02:09,379 and to get the Turkish crew aboard. 27 00:02:13,655 --> 00:02:17,448 By 10:15 p.m., the plane and most of its crew are at the gate. 28 00:02:22,344 --> 00:02:25,448 More than four hours after they were supposed to take off, 29 00:02:25,551 --> 00:02:28,758 the first of the passengers begin boarding the plane. 30 00:02:28,862 --> 00:02:31,827 They have a nine hour flight to Frankfurt ahead of them. 31 00:02:39,172 --> 00:02:42,620 Puerto Plata Alpha Lima Whiskey 301... requesting push back. 32 00:02:42,724 --> 00:02:47,793 Shortly after 11:30, Birgenair Flight 301 is given permission to leave the gate. 33 00:02:47,896 --> 00:02:49,000 Push back granted. 34 00:02:59,758 --> 00:03:03,103 Moments later, it taxis to the threshold of the runway. 35 00:03:05,413 --> 00:03:07,517 Cabin crew, take your seats, ready for takeoff. 36 00:03:09,413 --> 00:03:11,724 Cabin announcement is completed. 37 00:03:11,827 --> 00:03:15,034 First Officer Aykut Gergin is new to the 757, 38 00:03:15,137 --> 00:03:18,172 with fewer than 75 hours in the plane 39 00:03:18,275 --> 00:03:20,137 in the last three months. 40 00:03:21,448 --> 00:03:23,482 Thank you. Ready for takeoff. 41 00:03:23,586 --> 00:03:28,551 In contrast, Captain Ahmet Erdem is one of Birgenair most senior pilots. 42 00:03:28,655 --> 00:03:32,206 He's logged thousands of hours in this type of plane. 43 00:03:32,310 --> 00:03:35,482 Alpha Lima Whiskey 301, ready for takeoff. 44 00:03:35,586 --> 00:03:38,137 301 cleared for takeoff, runway 08. 45 00:03:38,241 --> 00:03:41,793 Cleared for takeoff. Runway 08, 301. Thank you. 46 00:03:43,620 --> 00:03:44,620 A good flight. 47 00:03:44,724 --> 00:03:45,689 Good flight. 48 00:03:45,793 --> 00:03:47,620 Good flight. 49 00:03:47,724 --> 00:03:51,793 Muhlis Evrenesoglu is on this flight as a Relief Pilot. 50 00:03:51,896 --> 00:03:56,517 Like First Officer Gergin, he's been flying the 757 for less than three months. 51 00:04:04,000 --> 00:04:08,206 As the plane accelerates to takeoff speed, a light rain begins to fall. 52 00:04:10,517 --> 00:04:13,275 - Power's set. - Okay, check. 53 00:04:13,379 --> 00:04:17,482 First Officer Aykut Gergin watches his air speed indicator 54 00:04:17,586 --> 00:04:19,758 for a routine instrument check. 55 00:04:19,862 --> 00:04:22,275 As the airplane's accelerating to takeoff speed, 56 00:04:22,379 --> 00:04:24,413 the First Officer calls 80 knots. 57 00:04:25,517 --> 00:04:28,344 - Eighty knots. - Check. 58 00:04:28,448 --> 00:04:31,034 The captain, in theory, should verify that 59 00:04:31,137 --> 00:04:33,413 his airspeed indicator also reads 80 knots. 60 00:04:35,448 --> 00:04:37,103 My airspeed indicator's not working. 61 00:04:41,689 --> 00:04:45,241 The captain's airspeed should read the same as his First Officer's. 62 00:04:45,344 --> 00:04:46,724 120. 63 00:04:46,827 --> 00:04:49,172 But the readings do not match. 64 00:04:49,275 --> 00:04:51,034 - Is yours working? - Yes, sir. 65 00:04:55,241 --> 00:04:56,310 You tell me. 66 00:04:56,413 --> 00:04:58,379 Erdem wants his First Officer to tell him 67 00:04:58,482 --> 00:05:00,931 when the plane hits takeoff speed. 68 00:05:01,034 --> 00:05:02,551 V-one. 69 00:05:02,655 --> 00:05:06,172 At 150 knots, the plane hits V-one, the point of no return. 70 00:05:07,517 --> 00:05:09,379 Rotate. 71 00:05:09,482 --> 00:05:12,172 The captain must pull back on his column and get the plane in the air. 72 00:05:12,275 --> 00:05:13,793 Positive climb, gear up. 73 00:05:15,103 --> 00:05:17,689 Positive climb, gear is up. 74 00:05:24,103 --> 00:05:26,275 At 11:42, the plane takes off. 75 00:05:28,827 --> 00:05:32,655 Seconds later, Captain Erdem's airspeed indicator comes to life. 76 00:05:35,517 --> 00:05:37,379 Is it possible to turn off the wipers? 77 00:05:37,482 --> 00:05:39,103 Okay, wipers off. 78 00:05:42,689 --> 00:05:46,137 - Climb thrust. - Climb thrust. 79 00:05:46,241 --> 00:05:48,379 First Officer Gergin reduces power 80 00:05:48,482 --> 00:05:51,448 to the engines for a gradual climb to cruising altitude. 81 00:05:55,000 --> 00:05:57,034 301 airborne 45. 82 00:05:57,137 --> 00:06:00,310 Switch over Santa Domingo 1243. 83 00:06:00,413 --> 00:06:02,862 1243. Bye bye, sir. 84 00:06:02,965 --> 00:06:04,793 Climbing through 2500 feet, 85 00:06:06,482 --> 00:06:08,758 First Officer Gergin establishes contact 86 00:06:08,862 --> 00:06:11,586 with the island's main tower in Santo Domingo. 87 00:06:11,689 --> 00:06:15,827 Alpha Lima Whiskey 301, climb and maintain 280. 88 00:06:20,827 --> 00:06:22,103 Center autopilot on, please. 89 00:06:23,655 --> 00:06:28,517 - Center autopilot has command. - Thank you. 90 00:06:28,620 --> 00:06:32,068 One minute and thirty seconds into the flight, the autopilot takes over. 91 00:06:40,758 --> 00:06:43,275 Onboard computers now make all the calculations 92 00:06:43,379 --> 00:06:46,068 and adjustments necessary to keep the plane flying safely. 93 00:06:49,310 --> 00:06:51,586 Almost immediately, the computer reports a problem. 94 00:06:52,620 --> 00:06:55,517 Rudder ratio. Mach airspeed trim. 95 00:06:55,620 --> 00:06:59,206 Two different alerts warn the pilots that the plane is traveling far too fast. 96 00:06:59,310 --> 00:07:00,620 Yes... trim... 97 00:07:00,724 --> 00:07:02,758 But the First Officer's airspeed indicator 98 00:07:02,862 --> 00:07:06,517 Shows the plane climbing at a normal speed, 220 knots. 99 00:07:07,448 --> 00:07:09,000 Something's wrong here. 100 00:07:16,310 --> 00:07:18,103 Unaware that there are any problems, 101 00:07:18,206 --> 00:07:21,724 the controller directs Birgenair Flight 301 to continue climbing. 102 00:07:22,965 --> 00:07:27,068 Alpha Lima Whiskey 301, report Pokeg. 103 00:07:27,172 --> 00:07:30,965 Okay, 280, I'll call you over Pokeg. 301. 104 00:07:31,068 --> 00:07:33,206 Okay, there's something crazy. Do you see it? 105 00:07:33,310 --> 00:07:36,448 In the cockpit, the situation gets more confusing. 106 00:07:36,551 --> 00:07:38,172 The First Officer's airspeed indicator 107 00:07:38,275 --> 00:07:40,586 shows that the plane is flying much too slowly. 108 00:07:43,724 --> 00:07:47,482 Mine shows only 200 now, and decreasing, sir. 109 00:07:47,586 --> 00:07:51,206 But the captain's gauge shows the plane flying far too fast. 110 00:07:51,310 --> 00:07:53,137 Three hundred and twenty-five knots. 111 00:07:55,000 --> 00:07:55,896 Both of them are wrong. 112 00:07:56,965 --> 00:07:58,482 What can we do? 113 00:08:00,000 --> 00:08:01,172 Let's check the circuit breakers. 114 00:08:01,275 --> 00:08:02,137 Yes, sir. 115 00:08:08,034 --> 00:08:09,965 As the first warning is eliminated, 116 00:08:10,068 --> 00:08:12,034 - a more persistent warning replaces it. - 117 00:08:13,103 --> 00:08:15,931 The over-speed warning tells the crew 118 00:08:16,034 --> 00:08:17,965 that they are approaching 350 knots. 119 00:08:18,068 --> 00:08:22,068 The maximum speed at which the plane was designed to fly at this altitude. 120 00:08:22,172 --> 00:08:23,379 Okay, it's no matter. 121 00:08:24,586 --> 00:08:26,448 Let's pull the air speed, let's see. 122 00:08:29,482 --> 00:08:32,275 Resetting the circuit breakers turns off the alarm, 123 00:08:32,379 --> 00:08:34,551 but it doesn't fix the problem. 124 00:08:34,655 --> 00:08:38,896 Captain Erdem's air speed indicator still shows he's flying much too fast. 125 00:08:39,000 --> 00:08:40,620 Now it's 350, yes? 126 00:08:43,896 --> 00:08:46,172 Confused by the conflicting information, 127 00:08:46,275 --> 00:08:48,931 Captain Erdem decides to do what the plane wants... 128 00:08:49,034 --> 00:08:50,206 He slows down. 129 00:08:50,310 --> 00:08:52,034 Let's take that like this... 130 00:08:56,344 --> 00:08:58,103 ...with terrifying results. 131 00:08:58,206 --> 00:09:00,172 Oh, God! 132 00:09:02,379 --> 00:09:06,000 The 757 is sending out warnings that are confusing the crew. 133 00:09:07,655 --> 00:09:10,000 Bewildered, the crew struggle to solve the problem. 134 00:09:13,172 --> 00:09:17,413 The lives of 189 people depend on them getting the answer right. 135 00:09:21,655 --> 00:09:24,413 Shortly after taking off from the Dominican Republic, 136 00:09:24,517 --> 00:09:27,620 Birgenair Flight 301 is in trouble. 137 00:09:27,724 --> 00:09:31,344 God! God! God! 138 00:09:31,448 --> 00:09:34,068 The cockpit is filled with an ominous sound... 139 00:09:34,172 --> 00:09:35,965 The stick shaker alert. 140 00:09:36,068 --> 00:09:39,655 Stick shaker warning is a warning of imminent stall. 141 00:09:39,758 --> 00:09:47,206 It means that the airplane is about to attain a speed so low, that it cannot sustain flight. 142 00:09:47,310 --> 00:09:51,689 The alert is so serious that it actually shakes the pilots' control columns. 143 00:09:51,793 --> 00:09:55,482 Combined with a loud rattling, it's impossible to ignore. 144 00:09:58,827 --> 00:10:03,379 To add to the crew's confusion, the plane begins to vibrate and dip wildly. 145 00:10:08,448 --> 00:10:12,862 I'm sure every passenger on the airplane knew something was unusual, because the aircraft 146 00:10:12,965 --> 00:10:16,448 started to, uh, started to shake in a very violent maneuver. 147 00:10:18,896 --> 00:10:21,172 It's not the only problem the crew is facing. 148 00:10:21,275 --> 00:10:23,586 A.D.I. 149 00:10:23,689 --> 00:10:27,896 The Attitude Deviation Indicator is basically a round gauge, 150 00:10:28,000 --> 00:10:29,517 that on this airplane is a screen 151 00:10:29,620 --> 00:10:31,482 that is blue on the top and brown on the bottom. 152 00:10:31,586 --> 00:10:35,448 And it shows not only the pitch of the airplane, but also roll. 153 00:10:35,551 --> 00:10:38,517 On the gauge, blue represents sky. 154 00:10:38,620 --> 00:10:40,517 The more blue, the steeper the climb. 155 00:10:44,137 --> 00:10:47,655 Right now it's showing that the plane's nose is pointing dangerously high. 156 00:10:49,275 --> 00:10:51,655 Then, more than 7,000 feet above the ocean, 157 00:10:51,758 --> 00:10:53,896 the plane rolls hard to the right, 158 00:10:54,000 --> 00:10:55,862 and begins to plummet from the sky. 159 00:10:57,241 --> 00:10:59,310 From the time that the stick shaker activates, 160 00:10:59,413 --> 00:11:04,931 it is now going to require proper action from the flight crew 161 00:11:05,034 --> 00:11:08,724 to sort this out, or they will end up losing control of it. 162 00:11:08,827 --> 00:11:11,689 The window of decisions is closing on them. 163 00:11:11,793 --> 00:11:14,586 For if they let it stall completely, 164 00:11:14,689 --> 00:11:17,793 maintaining control of the airplane will prove to be very difficult. 165 00:11:19,620 --> 00:11:22,655 Captain Erdem struggles desperately to get his plane to climb. 166 00:11:22,758 --> 00:11:24,000 Nose down! 167 00:11:25,655 --> 00:11:27,344 He has just a few thousand feet 168 00:11:27,448 --> 00:11:30,379 to pull a 100 ton airliner out of a deadly stall. 169 00:11:33,689 --> 00:11:36,931 The less experienced pilots utter prayers and offer suggestions. 170 00:11:37,517 --> 00:11:39,793 - Thrust. - A.D.I.! 171 00:11:41,103 --> 00:11:42,724 301... 172 00:11:42,827 --> 00:11:44,310 Squawk 377. 173 00:11:44,862 --> 00:11:47,275 Standby! 174 00:11:47,379 --> 00:11:53,068 Air Traffic Control is still unaware that Flight 301 is in grave danger. 175 00:11:53,172 --> 00:11:58,206 Not climbing? What am I to do? 176 00:11:58,310 --> 00:12:00,827 You can level off. Our altitude's okay. 177 00:12:03,172 --> 00:12:04,655 The plane is falling fast. 178 00:12:05,793 --> 00:12:08,103 Okay, 5,000 feet. 179 00:12:08,206 --> 00:12:13,103 Captain Erdem is trying to fly a plane that's become virtually uncontrollable. 180 00:12:15,896 --> 00:12:18,655 Thrust levers! Thrust! 181 00:12:18,758 --> 00:12:22,034 Gergin pushes the throttles to full power... 182 00:12:23,034 --> 00:12:23,931 but it doesn't help. 183 00:12:25,448 --> 00:12:27,655 The plane spirals towards the sea. 184 00:12:28,758 --> 00:12:31,551 Sir, pull up! 185 00:12:33,379 --> 00:12:35,517 Oh! What's happening? 186 00:12:37,655 --> 00:12:41,586 Alpha Lima Whiskey 301, Santo Domingo. Come in, please. 187 00:12:43,137 --> 00:12:47,620 Alpha Lima Whiskey 301, Santo Domingo. 188 00:12:48,344 --> 00:12:50,827 Come in, please. 189 00:12:50,931 --> 00:12:55,000 Less than five minutes after takeoff, Birgenair Flight 301 190 00:12:55,103 --> 00:12:57,275 - vanishes from radar. Alpha Lima Whiskey 301. 191 00:12:57,379 --> 00:12:58,241 Come in, please. 192 00:13:05,931 --> 00:13:08,000 The Dominican Navy begins searching 193 00:13:08,103 --> 00:13:10,034 for the missing plane and it's passengers. 194 00:13:14,793 --> 00:13:17,689 Enroute, I was always thinking of what I would find. 195 00:13:17,793 --> 00:13:22,241 I thought I would find people screaming, people yelling and asking for help. 196 00:13:22,344 --> 00:13:24,379 They discover something very different. 197 00:13:24,482 --> 00:13:27,689 The strong smell of jet fuel hangs over the water. 198 00:13:27,793 --> 00:13:30,551 Pieces of wreckage float on the waves. 199 00:13:32,137 --> 00:13:35,137 I thought to myself there is no one alive here. 200 00:13:35,241 --> 00:13:38,724 We didn't see any survivors and we didn't see bodies. 201 00:13:38,827 --> 00:13:41,275 I really thought the plane disintegrated on impact. 202 00:13:44,517 --> 00:13:48,206 Within hours, more than just wreckage begins floating to the surface. 203 00:13:57,827 --> 00:14:01,241 Around 5:20 in the morning, when the bodies started to come up, 204 00:14:01,344 --> 00:14:03,000 I did feel a great sorrow in my heart. 205 00:14:05,137 --> 00:14:07,206 I felt like I wasn't sure if I would have the strength 206 00:14:07,310 --> 00:14:08,655 to continue the work at that moment. 207 00:14:13,344 --> 00:14:16,000 The search continues by the light of the next morning. 208 00:14:19,275 --> 00:14:21,517 American and Dominican rescue ships 209 00:14:21,620 --> 00:14:24,827 scour a 1300 square kilometer area for survivors. 210 00:14:28,137 --> 00:14:29,034 None are found. 211 00:14:35,862 --> 00:14:40,172 Now it's up to the Dominican Republic's Aircraft Accident Investigation Bureau 212 00:14:40,275 --> 00:14:42,206 to find out what caused this accident. 213 00:14:45,586 --> 00:14:49,965 We established a base camp at a hotel on the Cabarete Beach, 214 00:14:50,068 --> 00:14:53,620 which was directly south of the accident site. 215 00:14:53,724 --> 00:14:57,103 Over the next couple of days, investigators, reporters, 216 00:14:57,206 --> 00:15:00,068 and some of the victims' families arrive at the hotel. 217 00:15:06,034 --> 00:15:10,793 Nearby, evidence of the disaster reaches the Dominican shores. 218 00:15:10,896 --> 00:15:13,896 Wreckage and passenger's possessions are washing up on the beach. 219 00:15:15,862 --> 00:15:20,758 Even the smallest piece could be a valuable clue as to what caused the crash. 220 00:15:24,724 --> 00:15:27,517 The USA's National Transportation Safety Board, 221 00:15:27,620 --> 00:15:30,241 Agrees to assist the Dominicans with their investigation. 222 00:15:34,862 --> 00:15:38,000 They send an investigator to Puerto Plata. 223 00:15:38,103 --> 00:15:42,103 We could see that this was going to take some international co-operation, 224 00:15:42,206 --> 00:15:44,206 to get to the bottom of the event. 225 00:15:44,310 --> 00:15:49,034 Robert MacIntosh will also provide support from the NTSB's Washington Offices. 226 00:15:49,137 --> 00:15:50,862 Any signal from the recorders? 227 00:15:50,965 --> 00:15:54,793 This particular accident was the first major loss 228 00:15:54,896 --> 00:15:59,206 of a Boeing 757 in the water. 229 00:15:59,310 --> 00:16:03,827 There was added urgency, because the aircraft was going into the livery 230 00:16:03,931 --> 00:16:07,275 of many American operated airlines, 231 00:16:07,379 --> 00:16:10,655 and on the market for the worldwide passenger service. 232 00:16:12,206 --> 00:16:14,689 In order to understand what had happened here, 233 00:16:14,793 --> 00:16:16,000 we only had one key. 234 00:16:16,103 --> 00:16:18,275 That key was the black boxes. 235 00:16:21,758 --> 00:16:23,344 Like all commercial airliners, 236 00:16:23,448 --> 00:16:26,724 the Boeing 757 carries a Cockpit Voice Recorder 237 00:16:26,827 --> 00:16:29,448 that records all the sounds in the cockpit. 238 00:16:29,551 --> 00:16:31,482 And a Flight Data Recorder, 239 00:16:31,586 --> 00:16:35,000 that records a wealth of information about the plane's operation during flight. 240 00:16:37,241 --> 00:16:40,172 We've got underwater locator beacons on these recorders. 241 00:16:40,275 --> 00:16:43,586 They work for 30 days upon immersion. 242 00:16:43,689 --> 00:16:48,551 But the ocean where the plane crashed is over 7,200 feet deep. 243 00:16:50,689 --> 00:16:53,413 We needed to locate them before the signals faded. 244 00:16:53,517 --> 00:16:57,862 And we also needed to remove them before the data was damaged by salt water. 245 00:16:57,965 --> 00:17:00,344 So we were in a race against time. 246 00:17:03,620 --> 00:17:08,586 The NTSB enlists the help of the US Navy, who hire a submersible called the CURV. 247 00:17:11,137 --> 00:17:13,793 CURV stands for Cabled Underwater Recovery Vehicle. 248 00:17:13,896 --> 00:17:15,793 It's a tethered vehicle. 249 00:17:15,896 --> 00:17:20,206 It has an umbilical and it's controlled by an umbilical. It's not autonomous. 250 00:17:20,310 --> 00:17:23,344 The CURV is essentially a remote controlled submarine, 251 00:17:23,448 --> 00:17:26,862 which can work at depths no manned submarine could handle. 252 00:17:32,827 --> 00:17:35,241 While the CURV travels from the United States, 253 00:17:35,344 --> 00:17:39,103 Major Souffront starts to examine the evidence he has. 254 00:17:39,206 --> 00:17:42,758 Radar on the ground tracked the plane as it climbed into the night sky. 255 00:17:42,862 --> 00:17:47,310 I have the radar. The history of the flight is recorded here. 256 00:17:47,413 --> 00:17:50,620 Investigators study the radar records, 257 00:17:50,724 --> 00:17:54,310 along with the conversation between the ground controllers and the crew. 258 00:17:54,413 --> 00:17:58,034 I have the recording from the control tower. 259 00:17:58,137 --> 00:17:59,862 Santo Domingo, good evening. 260 00:17:59,965 --> 00:18:02,517 Alpha Lima Whiskey 301, climbing with you. 261 00:18:02,620 --> 00:18:04,931 Alpha Lima Whiskey 301, 262 00:18:05,034 --> 00:18:07,655 c limb and maintain 280. 263 00:18:07,758 --> 00:18:09,275 Okay, 280. 264 00:18:09,379 --> 00:18:12,655 The exchange between the controller and Flight 301 is normal. 265 00:18:12,758 --> 00:18:15,275 The investigators detect no signs of trouble. 266 00:18:15,379 --> 00:18:20,551 The last communication between them was only disrupted with a "stand by". 267 00:18:22,379 --> 00:18:25,310 301 squawk 377. 268 00:18:25,413 --> 00:18:26,965 Stand by. 269 00:18:29,793 --> 00:18:32,448 As you heard, there is no reason why this plane went down. 270 00:18:32,551 --> 00:18:35,310 What had caused something to go wrong, 271 00:18:35,413 --> 00:18:38,482 to interrupt the flight path of the aircraft so rapidly? 272 00:18:38,586 --> 00:18:41,103 Certainly it was a good... It was a good question for us. 273 00:18:47,172 --> 00:18:51,275 Any debris that's found is taken to a Dominican military base to be examined. 274 00:19:02,379 --> 00:19:05,551 Investigators comb through the wreckage they've recovered. 275 00:19:05,655 --> 00:19:08,137 Pieces of the cabin, 276 00:19:08,241 --> 00:19:12,379 life vests, even part of the landing gear have all been found. 277 00:19:12,482 --> 00:19:16,551 Every piece of debris is studied for signs of an explosion, or fire. 278 00:19:22,379 --> 00:19:26,517 Investigators also check if any of the life vests are inflated. 279 00:19:26,620 --> 00:19:30,620 That would suggest passengers had some warning before the plane plowed into the sea. 280 00:19:32,172 --> 00:19:35,793 Cords on some of the life vest are hanging loose, 281 00:19:35,896 --> 00:19:39,758 But investigators conclude that could be the result of the plane's violent impact. 282 00:19:42,724 --> 00:19:47,034 The crash was so powerful it has compressed coffee cans into flat pieces of tin. 283 00:19:54,000 --> 00:19:55,793 The wreckage tells investigators, 284 00:19:55,896 --> 00:19:59,586 That the crash of Birgenair Flight 301 was sudden and violent. 285 00:20:01,275 --> 00:20:04,000 But they find no evidence that there was an explosion on board. 286 00:20:07,413 --> 00:20:10,344 Major Souffront looks into the possibility that the plane, 287 00:20:10,448 --> 00:20:12,758 which was called into service at the last minute, 288 00:20:12,862 --> 00:20:15,965 may not have been ready for the flight. 289 00:20:16,068 --> 00:20:19,517 Enmanuel Souffront. - Ah. Hi. 290 00:20:19,620 --> 00:20:23,034 I'd like to see some records of the Birgenair plane. 291 00:20:23,137 --> 00:20:25,172 All right. They're right here. 292 00:20:26,551 --> 00:20:28,206 This is it. 293 00:20:30,379 --> 00:20:33,758 It had been on the ground for some time in Puerto Plata, 294 00:20:33,862 --> 00:20:35,551 and that became interesting to us. 295 00:20:35,655 --> 00:20:40,482 Why would an operating company have an aircraft sitting there? 296 00:20:40,586 --> 00:20:44,862 Investigators discover that the plane wasn't on the ground for repairs. 297 00:20:44,965 --> 00:20:49,758 Based on maintenance records, the plane appears to have been mechanically sound. 298 00:20:49,862 --> 00:20:55,517 Birgenair simply didn't have enough passengers to justify the flight financially. 299 00:20:55,620 --> 00:20:58,413 So they kept the plane and the crew in the Dominican Republic 300 00:20:58,517 --> 00:20:59,896 for almost three weeks. 301 00:21:03,413 --> 00:21:07,655 The plane's maintenance records turn out to be one more in a series of empty leads. 302 00:21:13,517 --> 00:21:15,965 The CURV arrives in Puerto Plata harbor. 303 00:21:17,482 --> 00:21:19,241 On February 28th, 304 00:21:19,344 --> 00:21:24,068 more than three weeks after the crash, it slips below the waves, 305 00:21:24,172 --> 00:21:26,413 looking for the remains of the Birgenair jet. 306 00:21:32,379 --> 00:21:34,758 It takes the robotic submarine two hours 307 00:21:34,862 --> 00:21:38,310 just to descend the 7,200 feet to the ocean floor. 308 00:21:42,413 --> 00:21:46,172 From there, it sends back images of the wreck of Flight 301. 309 00:21:48,103 --> 00:21:50,862 The cockpit pretty much was sitting upright, 310 00:21:50,965 --> 00:21:55,551 and it was pretty much the nose of the plane, you know. 311 00:21:55,655 --> 00:21:58,310 And you could see the front part of it, it was obviously banged up, 312 00:21:58,413 --> 00:22:01,206 and cracked, and fragmented. 313 00:22:03,517 --> 00:22:07,344 The clues investigators need to solve the mystery of this plane crash, 314 00:22:07,448 --> 00:22:10,034 lies somewhere amongst the plane's twisted wreckage. 315 00:22:11,896 --> 00:22:15,103 The flight's black boxes are the top priority. 316 00:22:15,206 --> 00:22:19,724 The CURV quickly picks up the signal from a Pinger on one of the units. 317 00:22:19,827 --> 00:22:23,448 Operators must now maneuver the sub towards the sound. 318 00:22:23,551 --> 00:22:26,931 They have to be able to see the boxes to pick them up with the robotic arm. 319 00:22:30,172 --> 00:22:33,206 It takes just 90 minutes to find the first black box. 320 00:22:34,724 --> 00:22:37,517 The first one was sitting out in the open, 321 00:22:37,620 --> 00:22:39,758 Okay. It was where they could see it. 322 00:22:39,862 --> 00:22:42,241 And they picked the first box up. 323 00:22:42,344 --> 00:22:46,137 They grabbed ahold of it and they just kind of tucked the arm up in place. 324 00:22:46,241 --> 00:22:47,551 You know, so that they wouldn't lose it. 325 00:22:49,689 --> 00:22:52,482 The second black box is also heard. 326 00:22:52,586 --> 00:22:56,931 But after almost two hours, the CURV's cameras still can't see it. 327 00:22:57,034 --> 00:22:58,724 You know, they knew it was right there, 328 00:22:58,827 --> 00:23:02,034 and they were searching around a debris pile, 329 00:23:02,137 --> 00:23:04,413 and they could not physically see it, you know, 330 00:23:04,517 --> 00:23:05,862 with the cameras of the vehicle. 331 00:23:05,965 --> 00:23:09,137 So as they went around a couple of times they started, you know, 332 00:23:09,241 --> 00:23:11,724 lifting metal up and moving pieces out of the way. 333 00:23:11,827 --> 00:23:14,655 And then they did find the second box under some debris. 334 00:23:26,862 --> 00:23:29,275 Flight 301's Flight Data Recorder, 335 00:23:29,379 --> 00:23:31,724 and Cockpit Voice Recorder are brought to the surface, 336 00:23:31,827 --> 00:23:33,689 and loaded onto a waiting jet. 337 00:23:38,896 --> 00:23:43,206 Within hours, the black boxes are at the NTSB labs in Washington DC. 338 00:23:45,275 --> 00:23:48,896 Technicians prepare to extract the precious data from the boxes. 339 00:23:50,793 --> 00:23:54,413 Investigators hope it will tell them what happened aboard Birgenair Flight 301. 340 00:23:56,931 --> 00:24:02,103 They'll soon uncover a stunning miscommunication between a seasoned pilot and his plane. 341 00:24:08,068 --> 00:24:11,448 To unravel the mystery of Birgenair Flight 301, 342 00:24:11,551 --> 00:24:14,413 investigators are counting on the plane's black boxes. 343 00:24:16,689 --> 00:24:20,586 That flight data recorder was our key. 344 00:24:20,689 --> 00:24:26,586 So the technicians got busy and gave us plots, visual plots, 345 00:24:26,689 --> 00:24:32,310 of what was going on with engines, and air speeds, and so on, 346 00:24:32,413 --> 00:24:38,000 to allow us to try and understand why that aircraft slowed down, 347 00:24:38,103 --> 00:24:44,551 and then simply departed controlled flight and entered the ocean. 348 00:24:44,655 --> 00:24:48,000 That's great. That shows us all we need to see. 349 00:24:49,344 --> 00:24:52,517 So it's all the flight data recording. 350 00:24:52,620 --> 00:24:55,172 It's on a time line. Top is the pitch. 351 00:24:56,310 --> 00:24:59,000 We've got the air speed and the altitude. 352 00:25:01,000 --> 00:25:03,413 But check out the timeline, 44. 353 00:25:03,517 --> 00:25:08,551 Investigators immediately notice something unusual about the flight. 354 00:25:08,655 --> 00:25:12,482 Fifteen degrees pitch nose up. Seems high. 355 00:25:13,758 --> 00:25:16,793 - He's almost the maximum. - And then it stays that way. 356 00:25:18,482 --> 00:25:20,241 The plane began climbing normally. 357 00:25:26,068 --> 00:25:28,551 Center autopilot on, please. 358 00:25:28,655 --> 00:25:32,517 But investigators notice that shortly after the autopilot was switched on, 359 00:25:32,620 --> 00:25:35,275 the plane's nose pitched upward. 360 00:25:35,379 --> 00:25:38,862 They also see that the plane's airspeed seems much higher than it should be. 361 00:25:40,241 --> 00:25:42,206 Three hundred and fifty knots. 362 00:25:43,034 --> 00:25:44,586 It can't be right. 363 00:25:44,689 --> 00:25:48,344 There's something definitely wonky about the airspeed numbers. 364 00:25:48,448 --> 00:25:50,896 This brought us to the question of 365 00:25:51,000 --> 00:25:53,482 perhaps we should be looking over on the other side 366 00:25:53,586 --> 00:25:55,965 at the cockpit voice recorder and see 367 00:25:56,068 --> 00:25:58,620 what kind of information was coming from there. 368 00:26:01,620 --> 00:26:03,689 Can you cue that up and play it? 369 00:26:03,793 --> 00:26:08,172 Investigators soon start filling in the missing pieces of the puzzle. 370 00:26:08,275 --> 00:26:09,103 Eighty knots. 371 00:26:11,137 --> 00:26:13,586 My airspeed indicator is not working. 372 00:26:13,689 --> 00:26:15,344 They learn that Captain Erdem 373 00:26:15,448 --> 00:26:18,000 noticed that his airspeed indicator wasn't working. 374 00:26:18,103 --> 00:26:19,689 - Is yours working? - Yes, sir. 375 00:26:20,620 --> 00:26:21,517 You tell me. 376 00:26:21,620 --> 00:26:24,827 V-one. Rotate. 377 00:26:24,931 --> 00:26:29,448 But Erdem didn't think the problem was serious enough to abort his takeoff. 378 00:26:30,827 --> 00:26:33,241 The tape reveals that once they were airborne, 379 00:26:33,344 --> 00:26:36,655 the crew quickly became overwhelmed by a series of warnings. 380 00:26:36,758 --> 00:26:39,310 Rudder ratio. Mach airspeed trim? 381 00:26:39,413 --> 00:26:43,068 To investigators, the Captain seems to become increasingly bewildered 382 00:26:43,172 --> 00:26:45,413 by the messages he was getting from his plane. 383 00:26:45,517 --> 00:26:48,241 Mine shows only 200 now, and decreasing, sir. 384 00:26:48,344 --> 00:26:51,137 Both of them are wrong. What can we do? 385 00:26:51,241 --> 00:26:55,655 Investigators don't know why the Captain's airspeed indicator wasn't working. 386 00:26:55,758 --> 00:26:57,551 They do notice that the Captain's gauge 387 00:26:57,655 --> 00:26:59,965 came back to life as the plane started to climb. 388 00:27:01,137 --> 00:27:02,724 Okay, it's no matter. 389 00:27:02,827 --> 00:27:04,689 Let's pull the airspeed. Let's see. 390 00:27:04,793 --> 00:27:07,241 It's a telling discovery, 391 00:27:07,344 --> 00:27:10,793 Which leads investigators to focus their attention on the device 392 00:27:10,896 --> 00:27:13,206 that feeds the gauges airspeed information. 393 00:27:14,793 --> 00:27:16,000 The pitot tube. 394 00:27:17,896 --> 00:27:21,034 A pitot tube is an airspeed sensor, 395 00:27:21,137 --> 00:27:24,206 a pipe open at one end that responds to air pressure. 396 00:27:27,482 --> 00:27:32,034 When the plane travels forward, an increase in air pressure inside the pitot tube 397 00:27:32,137 --> 00:27:34,758 causes the airspeed indicator's needle to move. 398 00:27:37,517 --> 00:27:40,689 My airspeed indicator is not working. 399 00:27:40,793 --> 00:27:43,000 But if a pitot tube becomes blocked, 400 00:27:43,103 --> 00:27:45,655 it can send faulty readings to the plane's gauges. 401 00:27:48,896 --> 00:27:53,379 Blocked pitot tubes have been a factor in previous plane crashes. 402 00:27:53,482 --> 00:28:00,310 In 1982, a Boeing 737 crashed in heavy snow in Washington, D.C. shortly after takeoff. 403 00:28:02,103 --> 00:28:04,379 The pitot tubes were blocked with ice. 404 00:28:11,448 --> 00:28:15,620 Investigators suspect that the pitot tube which fed the Captain's airspeed indicator 405 00:28:15,724 --> 00:28:17,724 on the Birgenair jet was somehow blocked. 406 00:28:19,724 --> 00:28:22,310 But they know ice can't have blocked the tubes of a plane 407 00:28:22,413 --> 00:28:24,103 taking off from a Caribbean island. 408 00:28:25,758 --> 00:28:27,448 We don't know why it was blocked, 409 00:28:27,551 --> 00:28:32,827 but it presented a very, very interesting situation to us. 410 00:28:32,931 --> 00:28:38,379 We started carefully looking at what could cause that kind of thing to happen. 411 00:28:38,482 --> 00:28:39,275 Senor... 412 00:28:44,827 --> 00:28:46,931 Major Souffront has a theory. 413 00:28:47,034 --> 00:28:49,655 He returns to question the airplane's mechanics. 414 00:28:49,758 --> 00:28:53,379 - Senor Souffront... - We're done with these, thank you. 415 00:28:55,310 --> 00:28:58,758 I'd like to ask you some more questions about the Birgenair plane. 416 00:28:58,862 --> 00:29:01,551 Souffront suspects that mechanics may have taped over 417 00:29:01,655 --> 00:29:03,413 the pitot tubes during maintenance. 418 00:29:03,517 --> 00:29:06,172 It's a common procedure, but if the tape wasn't removed, 419 00:29:06,275 --> 00:29:08,068 it could have caused the deadly accident. 420 00:29:08,172 --> 00:29:10,310 Maybe a piece of tape was left on accidentally. 421 00:29:10,931 --> 00:29:12,517 No, sir. 422 00:29:12,620 --> 00:29:15,517 They didn't have to be taped. We never did anything with the Pitots. 423 00:29:18,172 --> 00:29:23,068 Did you put the pitot covers back on them when the maintenance was finished? 424 00:29:23,172 --> 00:29:25,344 It did not have any coverage with it. 425 00:29:25,448 --> 00:29:27,827 We did not take any off and we did not put any on. 426 00:29:34,551 --> 00:29:36,241 And that's when we discovered 427 00:29:36,344 --> 00:29:39,586 that the pitots had not been covered for the 25 days 428 00:29:39,689 --> 00:29:44,206 that the aircraft remained parked at the international airport in Puerto Plata. 429 00:29:46,379 --> 00:29:49,724 A pitot cover slips over the end of the tube. 430 00:29:49,827 --> 00:29:52,689 Regulations state that these covers must be installed 431 00:29:52,793 --> 00:29:57,206 any time a plane will be on the ground for an extended period of time. 432 00:29:57,310 --> 00:30:00,448 A prominent flag is meant to remind pilots and technicians 433 00:30:00,551 --> 00:30:02,137 to remove them again before takeoff. 434 00:30:04,655 --> 00:30:08,241 Investigators find that the Birgenair pitot tubes were never covered. 435 00:30:08,344 --> 00:30:11,000 And somehow, the uncovered pitots had become blocked. 436 00:30:14,137 --> 00:30:16,275 Recovering the tube from the ocean floor, 437 00:30:16,379 --> 00:30:20,379 is the only way for investigators to answer a pressing question. 438 00:30:20,482 --> 00:30:22,068 What blocked the pitot tubes? 439 00:30:23,241 --> 00:30:24,379 Nobody knows for sure. 440 00:30:24,482 --> 00:30:28,931 The evidence is 7000 feet down in the Atlantic Ocean. 441 00:30:29,034 --> 00:30:32,413 But even if the pitot tubes were blocked, 442 00:30:32,517 --> 00:30:35,206 how could it have caused the crash of a modern jet, 443 00:30:36,586 --> 00:30:40,413 and the death of 189 people? 444 00:30:40,517 --> 00:30:43,413 It's not like a car where you have only one speedometer. 445 00:30:43,517 --> 00:30:50,655 In this kind of an aircraft, you have a total of three airspeed indicators, 446 00:30:50,758 --> 00:30:52,793 and there is a flight data computer, 447 00:30:52,896 --> 00:30:55,517 which is computing the velocity in relation to the ground. 448 00:30:58,172 --> 00:31:00,000 I'd like to welcome you all this afternoon. 449 00:31:00,103 --> 00:31:01,620 As you know, I'm Bob Macintosh. 450 00:31:01,724 --> 00:31:03,793 Using information from the black boxes, 451 00:31:03,896 --> 00:31:07,103 the NTSB pieces together a real time animation, 452 00:31:07,206 --> 00:31:10,586 from lift off to the final moments of Flight 301. 453 00:31:10,689 --> 00:31:12,896 This is the indicator. 454 00:31:13,000 --> 00:31:17,379 The captain actually realized that his speed indicator was not working. 455 00:31:17,482 --> 00:31:19,551 - Is yours working? - Yes, sir. 456 00:31:19,655 --> 00:31:21,724 The big question for investigators is, 457 00:31:21,827 --> 00:31:25,344 how could one faulty airspeed source result in a crash? 458 00:31:25,448 --> 00:31:28,241 He realized at a time that he could have aborted. 459 00:31:28,344 --> 00:31:31,034 He could have turned back. But he chose to continue. 460 00:31:31,137 --> 00:31:34,620 Investigators analyze the Captain's every move, 461 00:31:34,724 --> 00:31:39,034 and find that he allowed a small error to escalate, and ultimately overwhelm him. 462 00:31:39,137 --> 00:31:40,000 Rotate. 463 00:31:43,034 --> 00:31:44,931 Positive climb, gear up. 464 00:31:48,689 --> 00:31:50,068 Moments after liftoff, 465 00:31:50,172 --> 00:31:53,275 Captain Erdem's airspeed indicator appears to be working. 466 00:31:53,379 --> 00:31:55,000 That means it is at odds. 467 00:31:55,103 --> 00:31:58,862 But investigators suspect the gauge is responding to changes in altitude. 468 00:31:58,965 --> 00:32:00,413 Climb thrust. 469 00:32:02,551 --> 00:32:05,000 As the plane climbs through the thinning atmosphere, 470 00:32:05,103 --> 00:32:07,655 the air trapped inside the tube expands, 471 00:32:07,758 --> 00:32:10,241 causing a buildup of pressure. 472 00:32:10,344 --> 00:32:11,655 Inside the cockpit, 473 00:32:11,758 --> 00:32:15,448 this causes the airspeed indicator needle to deflect. 474 00:32:15,551 --> 00:32:18,586 Even though altitude is causing the increase in pressure, 475 00:32:18,689 --> 00:32:22,551 the sensors mistakenly read it as an increase in airspeed. 476 00:32:22,655 --> 00:32:27,551 So, at this point, the takeoff is standard... 477 00:32:27,655 --> 00:32:31,137 Captain Erdem may have had five separate sources of airspeed to rely on, 478 00:32:31,241 --> 00:32:35,551 but investigators noticed that when the trouble started, he wasn't flying the plane. 479 00:32:35,655 --> 00:32:37,310 Center autopilot on, please. 480 00:32:37,413 --> 00:32:40,103 - Center autopilot has command. - Thank you. 481 00:32:40,206 --> 00:32:41,448 The autopilot was. 482 00:32:43,103 --> 00:32:45,586 And unless the crew reconfigures it, 483 00:32:45,689 --> 00:32:50,413 the autopilot gets its airspeed information from only one source. 484 00:32:50,517 --> 00:32:55,931 Remember, the autopilot gets its data only from the Captain's pitot tube. 485 00:32:56,034 --> 00:32:57,689 The one that was blocked. 486 00:32:57,793 --> 00:33:00,896 The data shows that the trouble on Birgenair Flight 301 487 00:33:01,000 --> 00:33:03,103 began when the autopilot took over. 488 00:33:07,034 --> 00:33:12,344 Right after the autopilot is engaged, the plane's nose begins to rise. 489 00:33:12,448 --> 00:33:15,448 Investigators suspect that the crew didn't realize 490 00:33:15,551 --> 00:33:20,206 that the blocked pitot tube was feeding the autopilot faulty information. 491 00:33:20,310 --> 00:33:23,896 The computer registered that the plane was traveling too fast, 492 00:33:24,000 --> 00:33:25,931 and raised the nose to slow it down. 493 00:33:26,034 --> 00:33:30,310 It soon rises to 15 degrees. Then it stays there. 494 00:33:30,413 --> 00:33:32,793 Raising the nose works like an air brake. 495 00:33:32,896 --> 00:33:36,034 It slows the plane by creating drag. 496 00:33:36,137 --> 00:33:40,862 The autopilot is programmed to never bring the nose higher than about 15 degrees. 497 00:33:40,965 --> 00:33:44,517 Any higher and the plane would slow down too much and stall. 498 00:33:46,000 --> 00:33:48,000 The autopilot's a pretty smart guy. 499 00:33:48,103 --> 00:33:52,241 He already knows he's got all the power that he's going to get for the climb. 500 00:33:53,896 --> 00:33:57,034 The only thing for the autopilot to do is raise the nose. 501 00:33:57,137 --> 00:34:00,931 And it raised the nose of the airplane to its limits of authority. 502 00:34:01,034 --> 00:34:04,517 But the autopilot was reacting to faulty information. 503 00:34:04,620 --> 00:34:07,551 Moments later, it sent out two different warnings. 504 00:34:07,655 --> 00:34:10,448 Rudder ratio. Mach airspeed trim? 505 00:34:10,551 --> 00:34:13,965 That the plane was traveling too fast to be controlled safely. 506 00:34:14,068 --> 00:34:17,517 The airplane begins picking up warnings, rudder ratio. 507 00:34:17,620 --> 00:34:22,586 A variety of things that the airplane is sensing problems. 508 00:34:22,689 --> 00:34:25,413 Okay, there is something crazy here. Do you see it? 509 00:34:27,620 --> 00:34:29,586 Yes, there is something crazy. 510 00:34:29,689 --> 00:34:32,689 Mine shows only 200 now, and decreasing, sir. 511 00:34:32,793 --> 00:34:34,482 Both of them are wrong. 512 00:34:34,586 --> 00:34:37,931 Investigators realized that Captain Erdem wrongly concluded 513 00:34:38,034 --> 00:34:41,275 that both airspeed indicators were malfunctioning. 514 00:34:41,379 --> 00:34:44,724 In fact, his First Officer's gauge was always correct. 515 00:34:44,827 --> 00:34:46,931 The plane was traveling much too slowly. 516 00:34:48,000 --> 00:34:49,586 What can we do? 517 00:34:49,689 --> 00:34:53,448 Captain Erdem no longer knows which instruments to trust. 518 00:34:53,551 --> 00:34:55,206 Let's check the circuit breakers. 519 00:34:55,310 --> 00:34:57,068 As they saw these caution lights, 520 00:34:57,172 --> 00:35:00,482 they decided they were going to start pulling some circuit breakers. 521 00:35:00,586 --> 00:35:01,896 But that would be rather strange. 522 00:35:03,551 --> 00:35:06,413 The actions of trying to reset circuit breakers 523 00:35:06,517 --> 00:35:11,413 is something's that pilots of older generation's aircraft 524 00:35:11,517 --> 00:35:15,206 have learned via experience of sometimes being able to get 525 00:35:15,310 --> 00:35:18,896 an errant system back functional. 526 00:35:19,000 --> 00:35:22,517 Resetting the circuit breakers turns off the alarm. 527 00:35:22,620 --> 00:35:27,000 But that needle continued to climb around the clock face, 528 00:35:27,103 --> 00:35:32,034 until it activated the overspeed warning. 529 00:35:33,517 --> 00:35:35,586 The autopilot system sent yet another warning, 530 00:35:35,689 --> 00:35:38,137 that the plane was traveling too fast. 531 00:35:38,241 --> 00:35:40,758 But the reality was just the opposite. 532 00:35:40,862 --> 00:35:43,655 The plane was slowing down. 533 00:35:43,758 --> 00:35:48,034 At this point, the overspeed indicator is on. They're going too slow. 534 00:35:48,137 --> 00:35:51,241 They think they're going too fast, and confusion has set in. 535 00:35:51,344 --> 00:35:53,241 Let's pull the airspeed. 536 00:35:53,344 --> 00:35:57,172 That's when Captain Erdem made the gravest error of all. 537 00:35:58,620 --> 00:36:02,034 You can see that he now pulls back on his throttles. 538 00:36:02,137 --> 00:36:06,103 Investigators realize that at the plane's already slow speed... 539 00:36:08,413 --> 00:36:11,034 ...pulling back on the throttles was disastrous. 540 00:36:11,137 --> 00:36:15,241 The crew got the most severe warning that a plane can send out. 541 00:36:15,344 --> 00:36:17,172 And that's when he gets the stick shaker. 542 00:36:17,275 --> 00:36:19,551 God! God! 543 00:36:19,655 --> 00:36:23,137 He's got a tactile sense coming through his flight controls 544 00:36:23,241 --> 00:36:26,206 that literally shakes the stick and says, 545 00:36:26,310 --> 00:36:27,689 you've got to lower this nose. 546 00:36:31,724 --> 00:36:34,448 In a matter of seconds, Captain Erdem was first warned 547 00:36:34,551 --> 00:36:36,758 that his plane was traveling too fast, 548 00:36:36,862 --> 00:36:40,137 and then that it was traveling dangerously slowly. 549 00:36:40,241 --> 00:36:42,448 They're in direct opposition of each other. 550 00:36:42,551 --> 00:36:46,068 And two warnings that you would never expect to get, one right behind the other. 551 00:36:46,172 --> 00:36:48,379 The autopilot 552 00:36:48,482 --> 00:36:52,103 is programmed to always disconnect when the stick shaker activates. 553 00:36:52,206 --> 00:36:54,724 It's up to the pilot to get the plane out of a stall. 554 00:36:56,689 --> 00:36:59,310 Once the autopilot reached its limits of authority, 555 00:36:59,413 --> 00:37:03,586 it said, "I've done all I can do. I'm out of here." 556 00:37:03,689 --> 00:37:05,448 When the autopilot disengaged, 557 00:37:05,551 --> 00:37:09,103 Captain Erdem suddenly found himself in control of the plane, 558 00:37:09,206 --> 00:37:11,241 at the moment of his greatest confusion. 559 00:37:11,344 --> 00:37:13,793 You watch the plane at the top of the screen. 560 00:37:13,896 --> 00:37:17,448 The cockpit recordings lead investigators to a stunning conclusion. 561 00:37:17,551 --> 00:37:19,172 A.D.I. 562 00:37:19,275 --> 00:37:22,241 Captain Erdem may not have recognized that his plane is about to stall, 563 00:37:22,344 --> 00:37:24,862 but the Relief Pilot behind him did. 564 00:37:24,965 --> 00:37:26,172 A.D.I. 565 00:37:26,275 --> 00:37:30,862 This additional pilot intervened to say "A.D.I., A.D.I.!" 566 00:37:30,965 --> 00:37:34,068 In other words, look at the A.D.I. and put yourself 567 00:37:34,172 --> 00:37:37,000 where you would normally see the nose of the aircraft. 568 00:37:37,103 --> 00:37:40,482 Five degrees nose high, ten degrees. 569 00:37:40,586 --> 00:37:45,931 So when the reserve pilot says "A.D.I." he is attempting to focus the captain's attention 570 00:37:46,034 --> 00:37:50,448 to roll and pitch which are becoming problematic. 571 00:37:50,551 --> 00:37:52,586 The relief pilot wanted Captain Erdem 572 00:37:52,689 --> 00:37:56,862 to recognize that the plane's nose was pitched dangerously skyward. 573 00:37:56,965 --> 00:38:01,241 Investigators can hear First Officer Gergin trying to convey the same message. 574 00:38:01,344 --> 00:38:02,931 Nose down. 575 00:38:03,034 --> 00:38:07,103 At this point, the first officer actually trying to lead the captain to some solutions, 576 00:38:07,206 --> 00:38:10,551 but not actually take control of the airplane. 577 00:38:10,655 --> 00:38:16,379 What the 757 desperately needed was airflow over the wings to generate lift. 578 00:38:16,482 --> 00:38:21,172 The only way to get that was to point the nose down and dive. 579 00:38:21,275 --> 00:38:23,551 What puzzles investigators is that the First Officer 580 00:38:23,655 --> 00:38:26,827 had a control column identical to the Captain's. 581 00:38:26,931 --> 00:38:30,482 He could have pushed it and brought the nose down himself. 582 00:38:30,586 --> 00:38:32,689 He may have been able to save the plane. 583 00:38:35,413 --> 00:38:39,448 But he didn't. Instead, he and the other Turkish crew member 584 00:38:39,551 --> 00:38:43,517 continued offering suggestions to their more experienced, but overwhelmed Captain. 585 00:38:43,620 --> 00:38:46,793 Not climbing. What am I to do? 586 00:38:46,896 --> 00:38:48,620 You can level off. Our altitude's okay. 587 00:38:48,724 --> 00:38:51,379 But the recording shows that Captain Erdem ignored 588 00:38:51,482 --> 00:38:54,827 valuable advice that could have saved the plane. 589 00:38:54,931 --> 00:38:59,448 And in the Birgenair case, there's a case of a relatively junior First Officer, 590 00:38:59,551 --> 00:39:02,827 looking at one of the most senior captains on the airline. 591 00:39:02,931 --> 00:39:06,000 It is not culturally appropriate 592 00:39:06,103 --> 00:39:08,862 for him to say, "I am going to take the airplane away from you." 593 00:39:08,965 --> 00:39:13,413 Instead, he tries to assist the captain, to lead the captain, 594 00:39:13,517 --> 00:39:16,034 but leave the captain in command. 595 00:39:16,137 --> 00:39:19,724 Other cultures, other training, other airlines, 596 00:39:19,827 --> 00:39:22,827 may very well have required the First Officer 597 00:39:22,931 --> 00:39:25,620 to physically take control of the airplane. 598 00:39:25,724 --> 00:39:31,413 I think the social atmosphere in the cockpit will prevail 599 00:39:31,517 --> 00:39:36,655 to revere age and experience to the point where it... it can kill somebody. 600 00:39:36,758 --> 00:39:39,000 And in this case, it looks like it did. 601 00:39:39,103 --> 00:39:42,862 The flight data recorder reveals that instead of pushing the nose down, 602 00:39:42,965 --> 00:39:46,068 Captain Erdem tried to get more speed from his engines. 603 00:39:46,172 --> 00:39:48,379 At this point, the crew goes to full power. 604 00:39:48,482 --> 00:39:50,137 Thrust levers! Thrust! 605 00:39:52,206 --> 00:39:54,103 At the angle the plane was falling, 606 00:39:54,206 --> 00:39:57,103 the engines couldn't get enough air. 607 00:39:57,206 --> 00:40:00,310 Applying full power was more than they could handle. 608 00:40:00,413 --> 00:40:03,310 The left engine quit first, 609 00:40:03,413 --> 00:40:05,724 With the right side at full throttle, 610 00:40:05,827 --> 00:40:09,862 the airliner swings around as though it's left wing were caught on a branch. 611 00:40:09,965 --> 00:40:14,517 The airplane goes into a classic full stall, where the nose drops, 612 00:40:14,620 --> 00:40:19,724 it falls on a wing, which is now a very life threatening condition. 613 00:40:19,827 --> 00:40:23,655 The 757 itself makes the situation worse. 614 00:40:23,758 --> 00:40:28,379 Like many modern jets, it uses a so-called swept wing design. 615 00:40:28,482 --> 00:40:32,689 The wings angle slightly backwards to reduce drag and increase fuel efficiency. 616 00:40:33,620 --> 00:40:35,172 But the design has a downside. 617 00:40:37,413 --> 00:40:41,551 One of the characteristics of swept wing jets is they get less and less stable. 618 00:40:41,655 --> 00:40:45,103 They're they're much harder to fly as they approach stall. 619 00:40:50,931 --> 00:40:53,310 Sir, pull up! What's happening? 620 00:40:55,241 --> 00:40:57,206 What's happening? 621 00:41:03,310 --> 00:41:06,344 To maintain control of a swept wing jet, 622 00:41:06,448 --> 00:41:09,310 with no more altitude than they had in this condition 623 00:41:09,413 --> 00:41:10,896 is very, very problematic, 624 00:41:11,000 --> 00:41:13,034 and they are not successful, and the airplane goes into the water. 625 00:41:15,413 --> 00:41:20,034 Investigators now know why Birgenair Flight 301 crashed. 626 00:41:20,137 --> 00:41:23,344 What they can't understand is why the flight ever left the ground. 627 00:41:23,448 --> 00:41:24,517 Eighty knots. 628 00:41:26,931 --> 00:41:28,344 My airspeed indicator's not working. 629 00:41:29,517 --> 00:41:31,206 At 80 knots, 630 00:41:31,310 --> 00:41:34,896 if the pilot and co-pilot's instruments disagree, takeoff should be aborted. 631 00:41:37,655 --> 00:41:39,103 V-one. 632 00:41:39,206 --> 00:41:41,620 Investigators are troubled that the captain took off 633 00:41:41,724 --> 00:41:43,724 knowing he had malfunctioning instruments. 634 00:41:46,586 --> 00:41:49,068 If something is not functioning correctly, 635 00:41:49,172 --> 00:41:55,172 it doesn't matter what it is, one should abort the takeoff at 80 knots. 636 00:41:55,275 --> 00:41:58,344 This decision on the part of the captain has been criticized. 637 00:41:58,448 --> 00:42:02,241 But there is a very short time window for this decision to be made. 638 00:42:04,551 --> 00:42:07,137 Members of the investigative team in Puerto Plata 639 00:42:07,241 --> 00:42:09,586 try to find any clues that might explain 640 00:42:09,689 --> 00:42:12,000 why Captain Erdem didn't abort his takeoff. 641 00:42:14,344 --> 00:42:16,172 It was raining that night. 642 00:42:16,275 --> 00:42:19,620 Perhaps he was worried that he wouldn't be able to stop his speeding plane in time. 643 00:42:21,758 --> 00:42:23,896 Procedurally, he's required to stop. 644 00:42:24,000 --> 00:42:28,793 But high speed aborted take-offs are something that are very serious, 645 00:42:28,896 --> 00:42:33,310 and that flight crews trained to avoid high speed aborted takeoffs if possible. 646 00:42:33,413 --> 00:42:36,206 And we certainly looked at the parameters of the runway 647 00:42:36,310 --> 00:42:41,689 to ensure that there was adequate runway in that particular situation. 648 00:42:41,793 --> 00:42:44,379 Careful measurements are taken. 649 00:42:44,482 --> 00:42:48,827 Investigators conclude that at 80 knots, when he first noticed the problem, 650 00:42:48,931 --> 00:42:52,793 Captain Erdem had enough runway left to bring his plane to a stop. 651 00:42:53,965 --> 00:42:55,724 He could have aborted his takeoff. 652 00:42:59,655 --> 00:43:03,758 There's also the question of the hastily assembled crew. 653 00:43:03,862 --> 00:43:07,689 Investigators now wonder if the last minute nature of the crew's call 654 00:43:07,793 --> 00:43:10,758 could have influenced their decision to take off. 655 00:43:10,862 --> 00:43:17,793 Birgenair started with a crew that probably didn't expect to fly that night. 656 00:43:17,896 --> 00:43:19,931 They didn't have adequate rest. 657 00:43:20,034 --> 00:43:26,206 They got out to the aircraft and perhaps were rushed in some of their planning. 658 00:43:26,310 --> 00:43:29,586 Investigators consider the possibility that the crew, 659 00:43:29,689 --> 00:43:34,896 who had been away from home for more than two weeks was simply too eager to get home. 660 00:43:35,000 --> 00:43:37,586 Zero eight three zero one. Thank you. 661 00:43:37,689 --> 00:43:40,413 - Good flight. - Good flight. 662 00:43:43,965 --> 00:43:46,034 This is the homesick factor, 663 00:43:46,137 --> 00:43:50,068 where the minor problems are ignored in order to get back home. 664 00:43:52,965 --> 00:43:57,275 But investigators will never know what was going through Captain Erdem's mind 665 00:43:57,379 --> 00:43:59,103 when he opted to continue his takeoff. 666 00:44:01,241 --> 00:44:04,000 In this case, the airplane is accelerating rapidly enough. 667 00:44:04,103 --> 00:44:05,793 The First Officer responds... 668 00:44:05,896 --> 00:44:07,310 V-1. 669 00:44:07,413 --> 00:44:08,655 ...which is the commit to fly speed. 670 00:44:08,758 --> 00:44:12,172 And by training, now the decision window has closed. 671 00:44:12,275 --> 00:44:13,241 They need to fly. 672 00:44:13,344 --> 00:44:14,655 Rotate. 673 00:44:19,000 --> 00:44:20,965 And immediately thereafter, they're airborne. 674 00:44:22,620 --> 00:44:26,068 Once the plane was in the air, its blocked pitot tubes 675 00:44:26,172 --> 00:44:30,034 caused Captain Erdem to make a series of critical mistakes. 676 00:44:30,137 --> 00:44:33,103 But how were the tubes blocked in the first place? 677 00:44:33,206 --> 00:44:37,034 Investigators will find that the death of 189 people 678 00:44:37,137 --> 00:44:40,068 was caused by something the size of a paperclip. 679 00:44:44,379 --> 00:44:47,482 Investigators now know that a blocked pitot tube 680 00:44:47,586 --> 00:44:53,103 led to a series of conflicting warnings that confounded Flight 301's Captain. 681 00:44:53,206 --> 00:44:56,586 Now they want to know how those same warnings would affect other pilots. 682 00:45:00,275 --> 00:45:03,586 We went to a flight simulator and in the simulator, 683 00:45:03,689 --> 00:45:06,103 we tried to recreate the conditions of what happened 684 00:45:06,206 --> 00:45:09,206 On the night of February 6th, 1996. 685 00:45:12,551 --> 00:45:15,310 Gentlemen, stand by. 686 00:45:15,413 --> 00:45:18,862 The simulator showed investigators that an overspeed warning, 687 00:45:18,965 --> 00:45:24,586 followed by a stick-shaker warning caused even the most seasoned pilots to freeze. 688 00:45:24,689 --> 00:45:27,413 The contradictory warnings were potentially dangerous. 689 00:45:33,793 --> 00:45:36,413 When the stick shaker activated, it was very unnerving. 690 00:45:36,517 --> 00:45:38,000 It's really overwhelming. 691 00:45:38,103 --> 00:45:42,379 That would tell me that Mach airspeed warning horn, 692 00:45:42,482 --> 00:45:49,586 combined with the stick shaker was a tremendously mind-boggling experience to a line pilot. 693 00:45:49,689 --> 00:45:52,689 As a result, the FAA issues a directive 694 00:45:52,793 --> 00:45:59,275 that simulator training for all airline pilots must include a blocked pitot tube scenario. 695 00:45:59,379 --> 00:46:03,275 The flight crew within Birgenair was faced with a large number of warnings, 696 00:46:03,379 --> 00:46:07,793 that kept coming and each warning added complexity to the environment. 697 00:46:07,896 --> 00:46:10,034 There's a lot of warning lights going off. 698 00:46:10,137 --> 00:46:15,241 This captain is in a condition that is deteriorating now very rapidly. 699 00:46:15,344 --> 00:46:20,241 So there is a dramatically increased demand on the captain to fly the airplane. 700 00:46:22,724 --> 00:46:25,965 The FAA asks Boeing to change some of those warnings. 701 00:46:27,827 --> 00:46:30,448 Those changes include the addition of a new warning, 702 00:46:30,551 --> 00:46:33,896 which tells both pilots that their instruments disagree, 703 00:46:34,000 --> 00:46:37,517 and the ability for pilots to more easily silence troublesome alarms. 704 00:46:41,931 --> 00:46:44,379 Finally, Boeing modifies its planes, 705 00:46:44,482 --> 00:46:50,448 so that pilots can easily choose which pitot tube the autopilot is using for airspeed readings. 706 00:46:55,724 --> 00:47:00,689 All told, more than 1400 Boeing planes worldwide are affected 707 00:47:00,793 --> 00:47:01,758 by the new directives. 708 00:47:04,758 --> 00:47:07,172 One final question remains. 709 00:47:07,275 --> 00:47:09,517 What had blocked the plane's pitot tubes? 710 00:47:17,034 --> 00:47:21,517 Investigators conduct an extensive search for Birgenair Flight 301's pitot tubes. 711 00:47:25,482 --> 00:47:26,344 They are never found. 712 00:47:30,000 --> 00:47:35,379 But at Puerto Plata's airport, they don't have to look far to find the likeliest suspect. 713 00:47:35,482 --> 00:47:38,241 It's not ice, and it's not dirt. 714 00:47:38,344 --> 00:47:41,551 We know that the area around Puerto Plata 715 00:47:41,655 --> 00:47:46,793 Has a lot of bees, and wasps, and... 716 00:47:46,896 --> 00:47:53,275 and animals, and birds, and insects that like to build nests. 717 00:47:53,379 --> 00:47:57,482 One of the insects is well known to pilots flying out of the Dominican Republic. 718 00:47:57,586 --> 00:47:59,137 It's called the Mud Dauber wasp. 719 00:48:01,206 --> 00:48:03,000 Bug experts tell investigators 720 00:48:03,103 --> 00:48:06,793 about an extraordinary connection between the wasps and a pitot tube. 721 00:48:14,137 --> 00:48:17,103 When a Mud Dauber is looking for an area to build its nest, 722 00:48:17,206 --> 00:48:18,862 it's looking for a site, 723 00:48:18,965 --> 00:48:21,206 a place that's more or less tubular. 724 00:48:25,379 --> 00:48:28,241 When the Mud Daubers make their mud nest, 725 00:48:28,344 --> 00:48:32,000 the mud, when it dries, hardens and condenses. 726 00:48:32,793 --> 00:48:37,482 It gets hard. 727 00:48:37,586 --> 00:48:41,586 Mud dauber wasps are squatters that make their nests in available places. 728 00:48:41,689 --> 00:48:46,000 Like crevices in homes, or even the pitot tubes of planes. 729 00:48:51,310 --> 00:48:54,896 That the plane was stopped for so long, 25 days, 730 00:48:55,000 --> 00:49:00,655 was enough time for any species of the Mud Dauber to build its nest in the pitot tubes. 731 00:49:03,068 --> 00:49:05,310 Investigators can only conclude 732 00:49:05,413 --> 00:49:08,724 that Mud Dauber wasps blocked the uncovered pitot tubes 733 00:49:08,827 --> 00:49:12,586 that fed the captain's airspeed indicator, which caused it to malfunction. 734 00:49:14,103 --> 00:49:16,517 They didn't put covers on the pitot tubes. 735 00:49:16,620 --> 00:49:20,413 So, at some point in time, extended time, 736 00:49:20,517 --> 00:49:23,517 there was an opportunity to get something like a Mud Dauber 737 00:49:23,620 --> 00:49:25,724 in that pitot tube. 738 00:49:28,137 --> 00:49:30,620 Investigators have their answer. 739 00:49:31,724 --> 00:49:34,413 On February the 6th, 1996, 740 00:49:34,517 --> 00:49:39,586 a tiny insect led to a series of mistakes that brought down an airplane, 741 00:49:39,689 --> 00:49:43,689 and changed the design of the world's most successful series of airliners.