- vor 22 Stunden
On 24 February 1989, United Airlines Flight 811's right-side fuselage partially rips off, ejecting nine people from the aircraft and causing an explosive decompression. The flight later lands safely at Honolulu without any more loss of life. It was later determined that an electrical short circuit caused the cargo door to open.
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00:00A massive explosion tears a hole in the side of a 747.
00:08What the hell was that?
00:10I don't know.
00:12Central United 811 Heavy, we had a bomb or something go on.
00:16We are descending rapidly.
00:18Everybody stay in your feet!
00:21Everything that wasn't bolted down just took off out.
00:25People are gone, the seats are gone.
00:28There was nothing there anymore.
00:31NTSB investigators suspect a crime.
00:34We were quite convinced that it was probably terrorism.
00:38But the physical evidence tells a different story.
00:42Check this out.
00:44I see it.
00:46It was very perplexing to us why this had happened and how it could have happened.
00:58United Airlines Flight 811 departs from Honolulu Airport just before 2 a.m.
01:16Gear up.
01:18Gear up.
01:19Captain David Cronin is at the controls of tonight's flight.
01:22It's his penultimate flight before retiring.
01:25I flew almost 35 years with United.
01:28LNAV VNAV?
01:29I've got over 30,000 hours of flight time and just about everything, military as well as civilian.
01:41Autopilot on?
01:42Check.
01:43First Officer Al Slader is also an experienced pilot who's flown with United for 25 years.
01:48Climb thrust.
01:49There's a third pilot in the cockpit.
01:50Is set.
01:51Second Officer Randall Thomas, the flight engineer.
01:52APU is off.
01:56When you get to the point where you're flying an aircraft like a 747, you are probably among
01:57the most experienced people on the airline.
01:58You are probably among the most experienced people on the airline.
01:59And that was certainly true for this crew.
02:00It was certainly true for this crew.
02:01The pilot pilot, Al Slader, is also an experienced pilot who's flown with United for 25 years.
02:04Climb thrust.
02:05There's a third pilot in the cockpit.
02:06Is set.
02:07Second Officer Randall Thomas, the flight engineer.
02:08APU is off.
02:09When you get to the point where you're flying an aircraft like a 747, you are probably among
02:23the most experienced people on the airline.
02:26And that was certainly true for this crew.
02:31There are 337 passengers on board.
02:35Stuart McClure, his mother and younger brother, are headed to Australia for a family visit.
02:41My stepfather was an executive for United Airlines, so he was over there on business.
02:48My mom decided to join him, but didn't want to fly alone, so brought us two boys with her.
02:55Flight 811's next stop is Auckland, New Zealand, for a stopover, before flying on to Sydney, Australia.
03:08The Boeing 747 is a large, long-range, wide-body airliner, powered by four turbofan engines.
03:16It's just one of the most amazing airplanes ever built.
03:21Upwards of a million pounds of takeoff weight, can travel 7,500 miles with reserves.
03:28The cruise speed of the airplane is Mach 0.85, which is well over 600 miles an hour.
03:34And it will outrun pretty much any airliner available today.
03:39I don't think we're going to top that son of a gun.
03:45There are thunderstorms ahead.
03:47Let's see here.
03:49We did notice that there were thunderstorms, so I left the seatbelt sign on.
04:03There are 16 flight attendants on board tonight's flight.
04:07One of them is Leonard Jenkins, who's off duty.
04:10So, we get underway.
04:13Everything seemed pretty normal.
04:15I really was just getting ready to take my eight-hour nap.
04:19Okay, Tom, we're going to detour over to the left.
04:23Center, United 811, heavy.
04:26We're going to be detouring.
04:27There's some weather.
04:29We're going to be going left, of course.
04:31United 811, deviation is necessary, approved.
04:34Roger.
04:35Airliners do not fly through thunderstorms, because it would be insane to do so.
04:44The lightning, the wind, perhaps funnel clouds.
04:49There are a lot of ways that a thunderstorm can kill you in an airplane.
04:55Looks like that's the end of it, right there to the right.
05:01Almost nine minutes into the flight, just as they get past the storm.
05:11What the hell was that?
05:13I don't know.
05:16I'm taking it down.
05:17I'm back to Honolulu.
05:18Central United 811, heavy.
05:20We have a mayday.
05:21We had a bomb or something go on.
05:26The engine.
05:27We've lost number three engine.
05:29The right inboard engine is inoperative.
05:32And we are descending rapidly.
05:35Coming back.
05:369811, heavy.
05:38Roger.
05:39Keep center advised.
05:40We have an emergency situation.
05:46You need to land at the nearest suitable airport.
05:49And that would be Honolulu, right behind them.
05:52Call flight attendant.
05:54Copy.
05:55To fly the plane back to safety, Captain Cronin needs to assess the damage.
06:03But cannot.
06:08A huge explosion seemed to rock the whole plane.
06:12Just a huge pop.
06:14And everything that wasn't bolted down just took off out.
06:18So this huge cloud of smoke and thought to myself, this is not real.
06:27This is something in my dream I've got to wake up.
06:31The air is escaping from the cabin.
06:33It's difficult to breathe.
06:35Everything just kind of went crazy.
06:38It knocked the wind out of me.
06:41And I kept thinking to myself, this is like, it feels like I'm suffocating.
06:44Put your mask on, Dave.
06:45Okay.
06:46I'm not getting any oxygen.
06:48The explosion has damaged the plane's oxygen supply to the crew and the passengers.
07:01We're not getting oxygen either.
07:02The pilots must get the plane down to 10,000 feet quickly before they run out of breathable air.
07:18First things first, get the airplane down where everybody is safe in terms of being able to breathe normally.
07:29Then work the other problems.
07:31Everybody stay in your seat!
07:36The next thing I remember, I was not in my seat anymore.
07:42And I was standing against the bulkhead.
07:44Stay in your seat!
07:48The whole right side of the airplane, like, the people are gone.
07:53The seats are gone.
07:54There was nothing there anymore.
07:57It was like a picture window.
08:01I could see the white caps of the ocean.
08:03I could see the two engines.
08:13Captain Cronin is having trouble turning the plane back to Honolulu.
08:16We've got a control problem here.
08:20With a full load of fuel on board, it's difficult to steer.
08:25Start dumping the fuel.
08:26I'm dumping.
08:28United 811 heavy.
08:30When able, for the soles on board and fuel a landing.
08:34Okay, stand by.
08:35We'll give you the information as quickly as possible.
08:37United 811 heavy, roger.
08:39And their troubles keep increasing.
08:40We've got a problem with number 4 engine.
08:41The right outboard engine is overheating.
08:42Can you maintain 240?
08:43Yes, just barely.
08:44You've got all this fuel because you're going to Auckland.
08:45And now you've lost two engines, and you've descended rapidly.
08:50The crew is facing a very serious situation.
08:53We're losing altitude.
08:54I know it.
08:55With that kind of weight, two engines are not going to keep you in the air.
08:56You're going to come down.
08:57You're helpless.
08:58You're helpless.
08:59You work too.
09:00Take your фотbergat, Wil Cartes- You doat in range.
09:03Both engines are simply drifting off.
09:04At 10 times!!!!
09:05Goodbo cohort of fans.
09:06What are you doing?
09:07No high-ris GIERT?
09:08If the crew is targeting the vehicle.
09:09You've got all of this fuel because you're going to Auckland.
09:10And now you've lost two engines.
09:11And you've descended rapidly.
09:12The crew is facing a very serious situation.
09:13ражck scientific messaging.
09:14We're losing altitude.
09:15I know it!
09:16With that kind of weight, two engines are not gonna keep you in the air.
09:18You're gonna come down.
09:21You're gonna come down.
09:25You're helpless. You have no control over what's about to happen to you.
09:30At that point, I realized, okay, this is where we die.
09:43Watch your heading. Watch your heading.
09:45You want to go direct to... We're going direct to Honolulu.
09:49Yeah.
09:50Eight minutes after an explosion on board United Flight 811,
09:56the pilots struggle to keep their aircraft from plunging into the Pacific Ocean.
10:00Okay, I'm going downstairs to see what the hell is going on.
10:08You got a fire up there.
10:09There's a fire out there?
10:19There was an engine.
10:20There was an engine on fire.
10:22With fuel, there was like a stream of fire.
10:28You just see flames just streaming out the back of the engines.
10:32Looks like it's engine number four.
10:34Go through the procedure to shut the engine down.
10:36Second officer, Randall Thomas, reaches one of the flight attendants.
10:54Please get us down.
10:55The right side is gone from about the first row right back.
11:09It's just open.
11:11You're just looking outside.
11:12What do you mean?
11:13Looks like a bomb.
11:14The fuselage is just open.
11:16I mean, the whole right side is gone.
11:19From about row one right back to, uh...
11:22Is anybody...
11:23Some people are probably gone.
11:27I don't know.
11:27You know, it's a terrible thing when you're a captain of an airplane and you lose passengers.
11:38We've got a real problem here.
11:43Not only have the pilots lost thrust in the two right engines,
11:46now the instruments aren't providing direction to the airport.
11:50They'll need the controller to guide them in.
11:52Uh, center united 811 heavy.
11:54We need a vector now.
11:56We're losing VOR.
11:57We're down to 6,500.
11:59We evidently had a bomb or something.
12:02A big section of the right side of the airplane is missing.
12:08United 811 heavy, do you have the airport in sight clear for visual approach?
12:13The controller gives the pilots permission to conduct a visual approach instead.
12:18But they're still too far out to see the airport.
12:21Uh, we're still 45 DME, so you watch us.
12:25United 811?
12:26I have you on radar.
12:29We've got to get down and wait here.
12:33I say we land overweight.
12:35We're at 652,000 pounds right now.
12:39Even though flight 811 has been dumping fuel,
12:42it's still 90,000 pounds over the safe landing weight.
12:46We've got 45 miles to go.
12:50United 811, uh, you're missing the right side of the cabin or the right wing, sir?
12:55That's affirmative.
12:56We're missing a section of the right side of the airplane.
12:59Part of the fuselage is missing.
13:02We need all medical equipment we can get and all equipment standing by.
13:06United 811 heavy, roger.
13:10Okay, put your harnesses on.
13:13Plan for evacuation.
13:15Tell them.
13:15Oh, you bet.
13:17Honolulu, United 811 heavy.
13:19We do plan to evacuate on the runway.
13:23United 811 heavy, roger.
13:29Okay, let me try to talk to the flight attendant.
13:31In the cabin, the crew is preparing the passengers for ditching.
13:43It was loud.
13:45We ran around getting lifeless on people.
13:50It's a feeling of, like, I'm not sure this is really going to matter
13:53at this point when we hit the water.
13:55I can't reach him down there.
14:04I say we land with ten degrees.
14:08Ten miles from the airport,
14:09the pilots make the final preparations for landing.
14:13We're higher than hell.
14:14But the airport still isn't anywhere in sight.
14:20United 811, turn right, heading 070.
14:25He's right there.
14:26Down to your right.
14:29Okay.
14:32The pilots must now make a right turn
14:35with no right-side engines.
14:37You've got all of the thrust
14:40coming out of these two turbofan engines
14:42on the left-hand side.
14:46And you've got two of them
14:48that aren't developing any thrust.
14:51It's a dangerous maneuver.
14:53If done incorrectly,
14:54the thrust from the left engines
14:56could put the plane into a steep roll.
14:59We're either going to land on the airport,
15:02in the water,
15:03or drastically change the topography
15:05of downtown Honolulu.
15:07With a massive hole in the fuselage,
15:12more than 45,000 pounds overweight,
15:15two dead engines,
15:16and unknown damage to the control surfaces,
15:19the pilots of United 811
15:21manage to line up with the runway in Honolulu.
15:27United 811 is cleared to land eight left.
15:29Equipment is standing by.
15:32Wind 05012.
15:35Cleared to land eight left.
15:36United 811 heavy.
15:37United 811 heavy.
15:39Okay.
15:39Well,
15:40let's try the gear.
15:42Head down!
15:47I see light!
15:56That's where it really became very, very real for us.
16:20We knew that whatever was going to happen to us, we were going to do it together.
16:25I'm coming off on the power.
16:26Moments from touchdown, the pilots slow the plane to make it easier to stop the overweight aircraft.
16:41Fifty feet.
16:43Watch the trim.
16:45Thirty.
16:45Center the trim. Center the trim.
16:48Ten.
16:49It was unbelievable how fast we were going.
17:02Go to reverse.
17:03Number two only because we're still at 170.
17:06The pilots hope reverse engine power will stop the plane before the runway ends.
17:25Prepare to evacuate.
17:27Probably the best landing I've ever made.
17:40Shut them down.
17:42Shut down the engines.
17:43Twenty-five minutes after the explosion, Flight 811 has returned to Honolulu Airport.
18:03Nine of the 337 passengers were blown out of the airplane over the Pacific.
18:21The search for them and the wreckage begins immediately.
18:25It was a huge area and very difficult for us to pinpoint where, over the water, it actually occurred.
18:36Ron Schleid from the National Transportation Safety Board, or NTSB, leads the investigation.
18:41We flew out of Washington and went into Honolulu.
18:48An FBI agent went with us, the bomb expert.
18:55They have jurisdiction to investigate for criminal activity.
19:01That hole's got to be at least 10 feet wide by 15 feet high.
19:07Forward cargo door is missing, too.
19:09The Boeing 747 has two cargo doors on the right side, the aft and the forward cargo doors.
19:19We could see from the ground cargo and baggage, and we could see the remains of seats and the cabin area.
19:31Looking at the airframe itself becomes important.
19:34We could see from the direction of failures, whether you have damage from inside the aircraft to outside, or the damages from outside in.
19:43The floor's buckled.
19:44Some of the seats are missing.
19:45The decompression likely broke the cabin floor beams.
19:50We were quite convinced that it was probably terrorism.
19:52There's damage on the leading edge and on the engines.
19:56The damage to the wing and engines is likely caused by debris that came off the plane.
20:03There's no sign of pity.
20:04Upon closer examination, investigators find no obvious signs of a bomb.
20:18The NTSB guys generally have an idea of what they're looking for.
20:26A peddling of the metal.
20:28They saw no evidence of that.
20:31No signs of fatigue or corrosion either.
20:35Once the FBI took the swabs for chemical residue and tested them, they reported they were all negative.
20:43And that was pretty conclusive evidence that there was not a bomb.
20:47The team now considers whether there was some kind of structural failure to the aircraft.
20:54All of the fractures appeared to be fresh overstressed damage, not any pre-existing damage.
21:03This made us consider that there was a problem with the door itself.
21:08We have some wiring from the door here.
21:13NTSB investigators turn their attention to what remains of the cargo door system.
21:18Okay, what else we got?
21:21Instead of using a plug door, which is stowed inside the cargo hole and gets jammed into the frame as the plane pressurizes,
21:29Boeing designed the 747 with an outward opening door to create more space for cargo in the hole.
21:36Looks like we at least have the pins.
21:42Investigators find a key component of the locking mechanism.
21:46The latch pins for the cargo door.
21:51The new 747 cargo door design uses a three-stage locking system.
21:57An exterior switch electrically powers the door to a near-closed position.
22:02C-shaped latches, or cams, then rotate around pins.
22:06A handle on the exterior of the door lowers metal sectors which secure the latches in place.
22:12There's some wear on the pins, but hard to tell for sure what it means.
22:18There was transfer of metal and discoloration.
22:22We couldn't tell for sure what the damage was, so we had to remove the pins and take them to a laboratory for further analysis.
22:30There's some wear for sure, but it's likely from the latches rotating around the pins as the door closes.
22:38Makes sense.
22:44Hang on.
22:46Have a look.
22:48Investigators find evidence of heat tinting on the surface of the pin.
22:53I see it.
22:55Heat tinting occurs when the surface oxide layer of stainless steel changes color due to heating.
23:01There's also some metal transfer from the latches on the pins.
23:06You're right.
23:08The presence of latch material on the pins suggests the separation of the cargo door was extremely fast and violent.
23:16The amount of force to cause a transfer of metal from the latches to the pins had to be enormous.
23:26There's metal from the latch in the same place on every pin.
23:33The location of the latch metal on the pins gives investigators their first big break.
23:39The latches were open and the door came off.
23:43The locking mechanism of the cargo door was designed to be fail-safe.
23:49So it's very perplexing to us why this had happened and how it could have happened.
24:00I'm checking the FAA records.
24:02I'll go through the Boeing ones.
24:05Has the locking system on the 747 cargo door failed before?
24:13I've got something.
24:15Two years ago, there was an incident on another 747.
24:20Look at that.
24:21In March 1987, Pan American Flight 125 was en route from London to New York when there was a pressurization problem.
24:30The door was open an inch and a half.
24:34The Pan Am agent used a wrench to close the door manually.
24:40And once he got it closed, he inadvertently backed the wrench up and opened the door slightly.
24:46The Pan Am latches were manually turned to the open position and the lock sectors were broken.
24:55How can the force of a socket wrench break the sectors?
25:00Well, look, get this.
25:02The lock sectors.
25:04They were made of a weak material.
25:07The locking sectors were made of aluminum so they would bend and break.
25:14What action was taken after the Pan Am incident?
25:19The FAA issued an airworthiness directive requiring that each lock sector be reinforced with a steel doubler.
25:29See, United Airlines, they had 18 to 24 months to do it.
25:34Maybe they hadn't got the work done yet.
25:36I'll check United's maintenance records.
25:41Did Flight 811 have weak lock sectors?
25:46Looks like the lock sectors hadn't been replaced yet.
25:51At the time of the accident, the accident airplane still had the aluminum sectors
25:57because it wasn't scheduled to be replaced for two months.
26:01Did you have any issues closing the door?
26:04Not at all.
26:05It closed fine.
26:06Investigators consider how the door was closed and if the latches were over-rotated like the ones on Pan Am 125.
26:14Did you close the door electrically or manually?
26:16I closed it electrically.
26:19I wouldn't have closed it manually.
26:21It takes too much effort.
26:23What do you mean?
26:24You have to crank the wrench 95 times.
26:27The ramp agent on 811 did not use a power tool as was used on Pan Am.
26:33This left us without any explanation for what happened.
26:43What'd you find out?
26:44Well, the ramp agent closed the door electrically, properly using the switch.
26:49And the dispatch mechanic said he did a circle check of the plane prior to departure.
26:56He checked the forward cargo door with a flashlight.
26:59And it was flushed to the aircraft.
27:06What about the cargo door indicator light in the cockpit?
27:10The second officer said that the light went out.
27:17Investigators confirmed that the second officer saw the cargo door light in the cockpit go off, indicating that the door was closed.
27:27While NTSB investigators consider other reasons why the cargo door opened, they get an update on recovery efforts.
27:40They mapped the currents and narrowed the debris field to 12 square miles.
27:47Finding the lost cargo door might be the key to the investigation.
27:52But take a look at the depth.
27:5514,000 feet.
27:58Recovery teams aren't able to search for wreckage at a depth of 14,000 feet.
28:03At that point, the deepest we had ever searched and recovered wreckage was 6,000 feet under the water.
28:12If the door was properly closed, then maybe it subsequently opened due to an electrical problem.
28:22Did the electrical system accidentally open the door in flight?
28:26According to the manual, when the plane lifts off the ground, all power to the door is disconnected.
28:35Electrical operation of the door, to open it in flight, was impossible.
28:41If not in the air, then...
28:48...maybe on the ground.
28:50We considered that there possibly could have been a short in the electrical system that caused the door to unlatch on the ground.
29:05Is this everything?
29:07Almost.
29:09We have all the electrical switches except one.
29:11Investigators perform continuity testing on the cargo door switches and relays recovered from the aircraft.
29:17This one's good.
29:20As is this one.
29:24Check this out.
29:29That's a burn mark.
29:35They also notice that some of the wiring insulation has stripped off.
29:40That switch is a closed circuit.
29:48It has nothing to do with opening the door.
29:50The exposed wire on the switch could not have caused the cargo door to open.
29:57We had ruled out most electrical system failures as the cause of the accident.
30:03So that had us look at other options.
30:11Here you go.
30:16The team now considers whether a mechanical failure caused the cargo door to open.
30:24Maybe there's something here.
30:25Investigators review the operations of the cargo door on four United 747s at Honolulu Airport.
30:35This is strange.
30:37It says here that one of the ramp agents kicked on a cargo door to get it open.
30:42They discover an instance of a cargo door opening only with the use of force.
30:47When we heard that the ramp agents had to kick the door, we figured that there was some type of misalignment, misrigging of the cargo door and its locking mechanisms.
31:01Maybe the door kicking was just an isolated case.
31:03Investigators turned to the maintenance report of the Flight 811 aircraft to determine if there was ever a fit issue with the forward cargo door.
31:16No fit or alignment issues were ever reported.
31:19Right, but check out when the plane was inspected.
31:26When it was empty.
31:27A 747 fully loaded with people, fuel and cargo can add upwards of 300,000 pounds to the aircraft, causing the fuselage to bend and distort.
31:45Get this.
31:47In December 1988, there were eight write-ups about door misalignment.
31:51Two months before the accident, the forward cargo door failed to close fully under electrical operation.
32:02A ill-fitting door could cause the latching motors to not drive the latches fully closed.
32:10Did United fix the problem?
32:12Investigators learned that an electrical switch on United Flight 811 couldn't properly close the misaligned cargo door.
32:26But was it ever repaired?
32:28The maintenance was deferred because they would close the door manually.
32:33If there was a fit issue and they would close it manually, that would explain the wear marks we found on the pins.
32:40The wear on the door indicated a long history of manual operation and misrigging of the door.
32:50Even worse, with repeated manual opening and closing of a misaligned door, the lock sectors could easily have been damaged if the latches were being over-rotated.
33:01With the latches and lock sectors still at the bottom of the sea, the NTSB is forced to conclude that the cargo door was sufficiently misaligned to prevent it from closing properly.
33:19When we write the final report of an accident, we present the evidence that we have and make our best conclusions based on that evidence.
33:30We knew there was mechanical damage to the door. We suspected that was the cause. And that's the way we wrote the report.
33:37In April of 1990, the NTSB published its findings. The report recommends the FAA issue a directive requiring the installation of a device to prevent the latches from over-rotating.
33:54But, we wanted to get the door. We really wanted to find the door to prove our theory.
34:02Three months after the NTSB publishes its report on United Flight 811, the US Navy offers to assist the recovery efforts.
34:20Side-scan sonar? Uh-huh.
34:26The Navy came to me and said, we've got a system that we're testing. It was experimental, a new sonar system, and it was at the time classified.
34:41A side-scan sonar device towed from a ship emits high-frequency sound pulses that bounce off the sea floor to create an image of the seabed and any debris that might be lying on it.
34:5714,000 feet, really.
34:59With the ability to scan deeper than previously possible, the Navy offers to test the device in the Pacific Ocean.
35:06All right, let's do it.
35:08They said, we would like to try and test it on that door, and they would do it for no cost to us.
35:15We said, sure.
35:29Nothing in this sector.
35:30NTSB investigator Frank Hildrop is on board the vessel searching for the cargo door.
35:39I felt a lot of pressure.
35:42This accident represented one of the deepest recoveries that was going to be attempted.
35:48They search an area of 12 square miles, divided into 57 sectors.
35:53Hang on.
35:54I think we got something.
35:55The team finds evidence of a debris field.
35:56There was pretty high confidence that they were in the right area, and the experts can tell roughly what they're looking at.
36:14Is it metallic in nature?
36:16Is it a good return?
36:18A three-person submersible vehicle called the Sea Cliff is deployed.
36:23The expedition confirms the debris is from Flight 811, but finding the cargo door proves difficult.
36:30We had some problems with weather, with the hurricane, with equipment failure, so there was a lot of stops and starts.
36:39Seacliff to Lani-Jui.
36:47After two months of searching...
36:50We have the door.
36:53...the missing piece is found.
36:55The door was in two pieces on the bottom of the ocean.
37:02We had to recover both pieces, get them on the ship, and take them to Honolulu.
37:10With the complete locking system recovered, investigators tried to confirm their theory that a misaligned cargo door caused the lock sectors to break.
37:20Just like we thought.
37:22The latches were in the open position.
37:23Check this out.
37:26But then they discover something unexpected and critical.
37:30These sectors aren't broken.
37:33They're just bent.
37:35The lock sectors were largely intact.
37:39They weren't damaged like we expected them to be.
37:42So that led us in a little bit more of another direction.
37:47No visible evidence of any burning or arcing.
37:49Investigators now reconsider a theory they previously rejected, that there was an electrical issue with the door.
37:59No signs of heat distress either.
38:01One of the things you can do is look inside the switches and see their condition.
38:07We always examine the wiring.
38:10We look for nicks or cuts when the wires are bundled together.
38:15Check this out.
38:17Investigators find a crucial piece of evidence.
38:19There's chafing on some of the wires in this bundle.
38:24It's proof that the conditions for a short circuit existed.
38:28All it takes for a short circuit to happen is for that conductor that's inside that insulation to touch another wire or touch a piece of metal.
38:38So we're always concerned about wiring in airplanes.
38:42All set.
38:44Can a short circuit open a locked door on a 747?
38:48Looks good.
38:50Give it a try.
38:51All right.
39:03Well, there you have it.
39:05We determined that probably the short circuit could have caused the motor to engage the latch cams and open the door.
39:17So we know there's no power to the door once the wheels lift off the ground.
39:21And the door was closed and locked here.
39:24So the short happened somewhere here during taxi.
39:31The short circuit causes the latch to partially open when the plane is still on the ground.
39:38Then when the plane approaches 23,000 feet.
39:44The significant pressure differential between the inside and the outside forces the door open and causes a massive decompression on board.
39:56Nine people are lost.
39:58Hello?
40:16Nine months after recovering the cargo door, investigators get disturbing news.
40:28It happened again.
40:31Another United 747 cargo door opened while on the tarmac in New York.
40:42Despite these incidents, the fleet is never grounded.
40:46I felt anger, you know, rage.
40:53My heart just goes out to the victims.
40:59Two years after the accident, the NTSB publishes a second report updating the cause.
41:05Opening of a cargo door on a large aircraft is a catastrophic event.
41:16It's an unacceptable event.
41:19It's like a wing falling off.
41:20The FAA and Boeing took more than two years to require changes.
41:33I remember it like it was yesterday.
41:34It just doesn't hurt so much and you don't think about it 24-7.
41:41The experience and the event that night, it told me I needed to make my life matter.
41:49Whether it be with the people that I share it with every single day or with what I put my energy towards every single day.
42:02The nine that didn't make it would expect that of us and of me.
42:07The nine that didn't make it would expect that of us and of me.