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Air Crash Investigation S25E06 Cabin Chaos 1080p
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面白系トランスクリプション
00:01After declaring an emergency,
00:03Injured passengers due to severe turbulence.
00:07China Eastern Airlines Flight 583
00:10seeks permission to land at a restricted U.S. military base in the Bering Sea.
00:15300 feet.
00:16The Pentagon have to take a look at what's happening.
00:19Is this a ruse to take a look at our radar site?
00:24Once the plane is examined,
00:26officials discount the possibility of espionage.
00:30Never seen anything like it before.
00:33This accident was definitely a catastrophic event.
00:38Two passengers died.
00:40The flight data recorder shows an erratic flight path.
00:45Wow.
00:46Being on this airplane was like being on a roller coaster.
00:52Only the cause is not what the pilots reported.
00:56The weather was clear.
00:57It's unlikely there was any turbulence.
01:00That changes everything.
01:26The crew of China Eastern Airlines Flight 583
01:30is on an overnight flight from Beijing to Los Angeles.
01:34Approaching 39 degrees north, 172 degrees east.
01:39A little bit back there.
01:46In 1993, China Eastern Airlines was a fairly new company.
01:51It had only been around a couple of years.
01:56The entire China aviation market was rapidly changing.
02:04China Eastern Airlines began operation in 1988.
02:09It was an exciting time with people finding that they suddenly had the ability to start travelling overseas.
02:21They could be on a level of the flight space.
02:22255 passengers started to end their meal service.
02:23have just finished their meal service.
02:26Some rest while others watch a movie.
02:33you press the switch and the air conditioning pops up the captain is a veteran pilot with
02:41more than 8,000 flying hours you try the captain was flying the airplane from the
02:51right seat because he was training the person who was in the left seat to be a new captain
02:58his first officer is a seasoned pilot but new to this plane an MD-11
03:09McDonnell Douglas developed the MD-11 as a fuel-efficient option for long-haul flights
03:16in the early 1990s approximately 100 of them were in service worldwide
03:24the MD-11 was an upgraded version of the DC-10 it was more efficient flying at cruise speeds although
03:32it had an automated system for flying the aircraft it was also changed in such a way that it was
03:38very
03:38responsive to pilot input if they're flying it manually this plane is one of five the airline
03:50bought to grow its international service she'll check numbers look at copy that
04:01during the cruise portion of the flight things are fairly routine flying at 33,000 feet the autopilot's
04:09on they've completed the first leg of the flight from Beijing to Shanghai and are now flying over the
04:19North Pacific bound for Los Angeles ladies and gentlemen the cabin crew is now passing out customs declaration cards which
04:32must be completed before entering the United States
04:42for many passengers this is their first overseas flight the process is unfamiliar do you postal code of the hotel
04:50we're staying yeah
04:56something's going on with the speed indicator the crew has pre-programmed a cruising speed into the computer which is
05:04now telling them to fly at a different speed
05:07the flight control computer is making numerous checks of various systems including air temperature airspeed fuel burn etc and they
05:15sometimes give suggestions to the pilots of how they can fly more efficiently in this case fly more slowly
05:23hmm I didn't fix it the captain tries to clear the computer's suggested speed
05:32it's not a big concern the airplanes flying fine but it's just odd and the captain tries to sort it
05:40out I'm gonna try this
05:47what's that while they're sorting out the speed issue the plane seems to hit some turbulence they start feeling this
05:58buffeting and the airplanes shaking around definitely something that will get any
06:03the pilot's attention suddenly one of the worst things a pilot can hear a stall warning alarm
06:12a stall warning alarm taking control the nose of the plane is pitching up which shouldn't happen while cruising at
06:20altitude with the autopilot on
06:22he needs to get the nose down because the airplane truly stalls it no longer has enough lift to stay
06:28flying it's gonna start dropping from the sky the captain pushes the yoke with enough force to override the autopilot
06:36autopilot off and to avoid a stall
06:46but now the nose pitches too far down
06:53the effects of the dive are felt even more severely in the cabin
07:03trying to gain control the airplane trying to understand what's going on the adrenal level goes dramatic real quick
07:11the captain uses all of his strength to keep the plane from diving
07:17but the aircraft pitches up steeper than expected
07:20exerting massive g-forces on everyone and everything in the cabin
07:25turbulence! seatbelt to everyone!
07:31what's going on?
07:33in essence this airplane was pitching up then pitching down
07:37it's almost like being on a roller coaster
07:43the captain attempts to level the plane
07:46but it goes into an even more extreme dive
07:56it happens so fast
07:58it happens so fast
07:58the forces are so great
08:01you wouldn't have time to even think of trying to get your seatbelt on
08:06eight degrees no doubt
08:08nine
08:09ten
08:12the captain halts the terrifying dive
08:16with severe consequences for unbuckled passengers
08:21you're being slammed back into your seat
08:23and then thrown back onto whatever might be below you at the time
08:30as the plane is tossed up and down
08:32the crew avoids a stall by keeping the nose from pitching up too much
08:37but the nose downs are a problem
08:40the pitch downs were more extreme than the pitch ups
08:44and the aircraft is losing altitude
08:49on the next oscillation the plane pitches down an astonishing 24 degrees
09:05the captain battles to stop the plane from diving
09:09while passengers struggle for their lives
09:12a lot's going on
09:18it's a dark night
09:20he's using his instruments
09:22forces are nothing like he's ever seen before
09:25and so it takes several of these cycles of this porpoising
09:28until finally he is able to get the airplane back to level
09:3730 seconds in
09:38the oscillations lessen
09:40and the plane begins to stabilize
09:42level at zero degrees
09:47to the crew
09:48that probably felt like it lasted
09:50you know
09:51an hour
09:52in reality
09:53it lasted a little less than a minute
10:00what just happened?
10:04no idea
10:06even with the autopilot on
10:07there's no time to relax
10:09there's no guarantee that what happened won't happen again
10:15they're flying over the vast Pacific Ocean
10:18nowhere near an airport
10:20and several passengers are seriously wounded
10:24we have many injuries
10:29we need to get this plane on the ground
10:36China Eastern Airlines flight 583 is back at 33,000 feet
10:41now it needs a place to land
10:44235 passengers on board
10:46unknown number injured
10:48call it in now
10:51flight 583 requesting the nearest airport
10:54this is an emergency
10:56airspeed
10:59298 knots
11:01angle of attack
11:03zero
11:05for now everything seems to be working
11:09all they know at the moment is the airplane's flying
11:11what appears to be fine
11:13but then again
11:14until we land and get out and look at it
11:16we don't know
11:21with injured passengers on board
11:23the captain can't take the risk of flying 3700 miles
11:26to their destination
11:27Los Angeles
11:29we're 39 degrees north
11:31176 east
11:33copy
11:34please stand by
11:35the crew considers where they might land
11:39are we closer to Russia or to the US
11:44this far out over the Pacific
11:46mainland Russia is 2200 miles to the northwest
11:51Anchorage Alaska is the same distance to the northeast
11:56they're in one of the few places in the world where there's nothing really close by
12:01ladies and gentlemen
12:03the plane encountered severe turbulence and the damage is being assessed
12:07please cooperate and be patient
12:10we are planning for an emergency landing
12:14flight 583 is overseen by air traffic control in Honolulu 2,000 miles away
12:20what is your emergency
12:23injured passengers due to severe turbulence
12:27stand by please
12:29it's an unusual situation
12:31a civilian Chinese airplane in international airspace
12:36in urgent need of an airport
12:38looks like it's either Anchorage or Shemya
12:40waiting for clearance
12:45Shemya
12:46a tiny island on the western tip of Alaska's Aleutian island chain
12:51is about a thousand miles away
12:53Anchorage is twice as far
12:56because it's an air force base
12:59Shemya has medical staff and equipment to treat injured passengers
13:04Shemya
13:05Shemya is basically an island in the middle of nowhere
13:09operated by the US Air Force
13:11is strictly for military operation
13:14there are no commercial flights
13:17the decision to allow the China Eastern Airlines flight to land
13:21is taken to the highest levels
13:25the Pentagon have to take a look at what's happening here
13:28is this a real emergency
13:31or is this a ruse
13:33to take a look at our big radar site we have there
13:37I imagine there was a lot of discussion going on from a security point of view
13:43clear to divert to Shemya
13:45we're clear to divert to Shemya
13:49the captain had a choice to make
13:51do I go to the closest available runway which was Shemya
13:55or do I go further on to Anchorage
13:57which might be catastrophic
13:59had there been damage to the aircraft
14:02ok
14:04we're going to Shemya
14:06we have received permission to land at Shemya Air Force Base
14:10damage to our aircraft is unknown
14:15can we get a weather report
14:18the crew prepares for a difficult night landing
14:21on an airstrip they've never seen before
14:24with unknown damage to their airplane
14:27Shemya has extreme weather
14:30heavy cloud cover, fog and high winds is the norm
14:34after a nerve-wracking two hours in the air
14:37the plane is now only 40 miles from the airbase
14:41altimeters set
14:43they really don't know what's going to happen when they slow up
14:49did the elevators get damaged
14:50will the landing gear come down
14:53there's a lot of things they've got to be concerned about
14:57as they get closer the weather intensifies
15:01Islas armed
15:02runway 28
15:04the crew connects to an instrument landing system
15:07that uses radio signals to guide them in
15:102,000 feet
15:13the crew at this point is going to be under a good amount of stress and pressure
15:18to make sure that they do it right the first time
15:21wanting to get the people to help as quickly as possible
15:28Autopilot off
15:31taking control
15:32they're now only six miles from the runway
15:35gear down
15:46line the gears down
15:59500 feet
16:01400 feet
16:05300 feet
16:07the ILS gets the plane as far as 200 feet above the ground
16:12then the captain has to fly by sight
16:25I have touched down
16:42the emergency is over
16:44the emergency is over
16:45the emergency is over
16:47the plane is safely on the ground
16:55medical teams immediately assess passengers
16:59the findings are grim
17:03149 people are injured
17:05dozens of passengers and crew are taken to hospital
17:08one passenger is dead
17:11another is fatally wounded
17:13this accident was definitely a catastrophic event
17:22many many passengers and flight attendants were seriously injured
17:33passengers who are well enough to travel are flown to Anchorage International Airport and transferred to hospital for treatment there
17:41at that time I think I would die of course surely I would die
17:50a team of investigators from the National Transportation Safety Board or NTSB flies in from Washington
18:01Greg
18:01Greg Fythe leads the investigation
18:09never know anything was wrong with it from here
18:13they did land on U.S. territory and so we were going to conduct the investigation
18:18and because it was an MD 11 was a relatively new airplane
18:22I'll go check inside
18:24we needed to find out what really happened
18:33as soon as investigators arrive at Shemya
18:36they inspect the aircraft for signs of damage
18:43I'll go check out the cockpit
18:51we didn't have a lot of information
18:53we didn't have a lot of information
18:54we knew that there had been an emergency landing
18:56that the airplane had encountered severe turbulence
18:59with that kind of information you can build a lot of different storylines
19:07the cockpit looked normal
19:11but as soon as you looked down the aisle
19:14it looked like a bomb had gone off
19:22never seen anything like it before
19:27row 15
19:29bend down on seats B and C
19:33C
19:34C 23 B
19:35signs of impact damage
19:38the cabin gives them a glimpse into the tragedy that unfolded during the flight
19:44there was a lot of baggage that had come out of the overheads
19:47broken glasses, broken dishes
19:50they are basically lethal weapons if they are flying through the air
19:57check out those marks
19:59likely scuff marks from shoes
20:06that was really disturbing because passengers
20:09they had to have been floating not only in space
20:12but they had to have rotated
20:14so that their feet were above their head
20:19seems like there was a sudden pitch down
20:32the damage is worse in the ass section
20:37someone got badly hurt here
20:42people in the back are more likely to get injured
20:45that tail of the airplane tends to get whipped about
20:48almost like a fish tail
20:52let's see if we can find some passengers that are well enough to talk to us
20:58we really needed statements from passengers and flight attendants
21:02who had experienced the violence
21:05they were going to give us a first-hand account of what really took place
21:13thanks for coming in today
21:22okay
21:24when the incident happened
21:25what's the first thing you remember?
21:30the plane started to shake
21:32then it went up and down like this
21:36the shaking could be the result of turbulence
21:39how quickly did this happen?
21:42so fast
21:44i think i'm lucky to be alive
21:58when the plane started shaking
22:00did the crew give a turbulence warning?
22:09one of the common causes of turbulence tends to be bad weather such as rain or hail storms
22:16if the turbulence is unforeseen
22:19passengers who don't have their seat belts on are a much greater risk for injury
22:31did you see out a window? was there any bad weather?
22:36not that i could see
22:42thank you
22:44they described that the flight was actually relatively smooth
22:47they didn't notice any kind of turbulence
22:50there was nothing unusual about the flight leading up to the main event
23:00investigators turned to the weather reports from the day of the incident
23:04this isn't what i expected
23:07the weather was clear
23:09it's unlikely there was any turbulence
23:12that changes everything
23:16what about the elevators?
23:23definitely worth a look
23:27a damaged elevator could have led to a loss of control
23:31we had to determine whether or not there was a problem
23:37elevators are hinged flaps on the trailing edge of the horizontal stabilizer
23:43when the pilot pushes or pulls on the control column
23:46the elevators respond by rising or lowering creating pitch
23:54investigators look for any exterior signs of elevator damage
23:59everything looks good on the outside
24:01i'll check for internal damage
24:04we use what's called the tap test
24:07and it's a very simple test
24:09and in fact it's done with a quarter
24:13it should sound solid
24:17if you hear a hollow type of sound
24:20that's a very good indication that there is a delamination
24:24in one or multiple layers of that composite material
24:29i'm hearing nothing out of the ordinary
24:33after we cleared the elevators we still had to understand
24:36what may have caused this airframe buffet
24:39no substructure failures or anomalies were found
24:45nothing wrong with the elevators
24:48then what else?
24:55what did the captain have to say?
24:57check the status of his interview
25:05we wanted to know what he was doing as far as his duties and responsibilities leading up to the upset
25:16i'm taking control
25:26hey, you're not going to believe this
25:29page 22
25:32NTSB investigators turned to the captain's account of China Eastern Airlines Flight 583's high altitude incident
25:40he mentions turbulence before the onset of the incident
25:43we knew there wasn't any
25:44that's not all
25:45keep reading
25:49he noticed the slats were extended?
25:52yep
25:57the MD-11 has eight slats on the leading edge of each wing
26:02when extended they change the curvature of the wing creating more surface area
26:08used in tandem with the flaps they provide extra lift during takeoff
26:13that's weird
26:14why would the slats be extended during cruise?
26:23investigators now have a very promising lead
26:29there's no reason to deploy slats at 33,000 feet
26:32soon as you would see that the slats are extended at that altitude at cruise
26:36that would be an alarm bell
26:42if the slats were out
26:43if the slats were out
26:45that would explain the pitch-up described by the passengers
26:49they're controlled by this handle here
26:53you should check the entire slats system
26:58we had to determine whether one or more of the components in that slats system had either malfunctioned or failed
27:14first look is clean
27:16no obvious signs of damage
27:19we had to access all the mechanical linkages
27:22there's hydraulic valves, electrical mechanical systems
27:26so we had to make the determination whether or not they were functioning as designed
27:32okay, let's test them
27:33extend the slats
27:38there's one handle in the cockpit that controls both the slats and the flaps
27:48typically the slats are deployed first
27:50so when you pull it back to the first notch
27:52the slats get deployed
27:54you pull it back further, the flaps get deployed
28:00all seems to be working fine
28:02not seeing any mechanical issues at all
28:06they examined the whole system
28:08and they extended normally, they retracted normally
28:11there was no obvious damage to the aircraft
28:16I still think the slats are part of the problem
28:20maybe it wasn't mechanical
28:25good thought
28:26maybe it wasn't
28:30everything showed that the airplane was perfectly fine to fly
28:35and so the investigation would focus to
28:38what the pilots did or did not do
28:41that caused the upset
28:43did the pilots somehow deploy the slats at high altitude
28:50now we had to determine whether or not those slats had been deployed
28:54inadvertently
28:56you got all the reports
28:59yep
29:01have any pilots accidentally deployed the slat handle in an MD-11
29:07they review old incident reports
29:13we do what's called a look back
29:15so we're looking at whether or not this is an isolated event or systemic problem
29:23hey
29:24look at this
29:25what have you got
29:28ten incidents in two years
29:35clipboard fell on the handle
29:36first officer rested his arm on the handle
29:40slats extend in cruise flight
29:46there had been other events with this particular system
29:50either an uncommanded or inadvertent deployment of the slats
29:54fifty percent were due to some sort of pilot contact with the slat handle
30:01if the pilot didn't know he knocked the handle
30:03he probably didn't hit it that hard
30:07so it could have moved
30:09to the slats only position
30:13deploying the slats at high speed would trigger the buffeting
30:17which was likely misconstrued as turbulence
30:27what was happening in the cockpit right before the buffering started
30:32captain said he was using the control keypad
30:34here
30:38they are really close together
30:42investigators have a new theory
30:44a simple movement could have triggered the entire chain of events
30:50we've got to see how easy it is to knock this handle out of place
31:00investigators test whether the crew of china eastern airlines flight 583 could have inadvertently
31:07knocked the slat handle out of position during flight
31:10ready? ready
31:14hey move
31:16now the first officer was sitting in the left seat so he could have knocked it
31:20but the captain said he was playing with the keypad
31:24they tried different techniques about
31:27okay, if you hit the handle from the right side back
31:31you hit the handle from the front side back
31:33what would it take to jar the handle out of position?
31:38hang on, let me try something
31:43bingo
31:44that's what the captain was doing when the buffeting started
31:47didn't take much force either
31:51it's a major breakthrough
31:53proof that the handle could have been accidentally moved while the captain reached for the keypad
32:01it was real easy during normal movement using the keypad on the center pedestal
32:07to inadvertently strike the handle and cause an uncommanded slat deployment
32:17investigators have uncovered a dangerous design flaw in the MD-11
32:22so the handle probably moved in flight
32:27and then the captain retracted the slats
32:32the captain said that he saw that the slat handle had been out of position
32:36at about the same time the stall warning system triggered
32:39he immediately moved the slat handle back into the retract position
32:46the slats were fully extended for just seconds
32:51now, that explains the initial pitch-up
32:55but...
32:56there has to be more to it than that
32:57the plane went up and down several times
33:00the slats wouldn't have caused that
33:10investigators still don't understand why flight 583 experienced so many extreme oscillations
33:17the cockpit voice recorder would record for 30 minutes and override itself
33:23so we didn't have that information
33:25however, with the flight data recorder
33:28we could see control positions
33:30we could gain other information
33:34ok, first up, let's look at pitch
33:38so we have five big oscillations in roughly 20 seconds
33:41biggest pitch-up is here
33:44oscillation 1, 9.5 degrees
33:46biggest pitch down happens here
33:49minus 24 degrees
33:51oscillation number 4
33:53for the first time
33:55they can see the severity of the oscillations
33:58passengers describe
33:59and it starts to stabilize
34:02here
34:05the team launches into a second-by-second analysis of the first pitch-up
34:14the slats were extended here
34:16during the beginning of the first pitch-up
34:20it's gradual at first
34:23is the autopilot on?
34:29so it's on for the first few seconds
34:32and it would have been fighting to bring the nose down
34:35when the slats deploy
34:37the airplane will have a natural nose or pitch-up tendency
34:40with the autopilot engaged
34:42it will actually correct for that pitch-up
34:45and return the airplane to a level attitude
34:50but
34:52the autopilot's losing the battle
34:53the pitch keeps increasing
34:56and that would trigger the stall warning
35:02yep
35:03stall warning turns on here
35:06a few seconds later the autopilot disengages
35:09and now the nose dives down sharply
35:13I'm taking control
35:17autopilot
35:19off
35:26so the captain's at the controls when the big drop happens
35:31show me the elevator data
35:38wow
35:40so the captain made some elevator inputs
35:42starting right here
35:45that is a huge nose down command
35:52it's an overcorrection
35:53it's an overcorrection
35:54and I think I know why
35:57I'm taking control
36:02autopilots are designed so they won't just let go easily
36:06you don't want somebody just accidentally bumping against the controls
36:10to suddenly knock the autopilot off
36:15he felt the resistance
36:17and pushed against that resistance of the autopilot
36:20disengaging it
36:24unfortunately that led to an excessive amount of nose down elevator command
36:32he started a chain reaction of pushing and pulling too hard on the yoke
36:39at high altitude
36:41the pitch forces are very light on the yoke
36:45so when he pulls back to get the nose up
36:49he's putting in too much up force
36:54it goes up too high
37:00he pitches down, it goes down too low
37:10and he puts in several cycles on the control yoke
37:14trying to get back to normal
37:20it's called a pilot induced oscillation
37:23or PIO
37:25the pilot over corrects
37:27and the plane responds creating increasingly uncontrollable movements
37:36once again to the oscillation it's hard to stop
37:42everything's happening fast
37:47we were able to calculate that the occupants of the airplane experienced 1.24 negative G's and 2 positive G's
37:58no wonder there were so many injuries
38:01including 2 fatalities
38:05he did get the plane back under control
38:07just took a while
38:10pilot induced oscillations
38:12can cause extreme stresses on the aircraft
38:16usually the best course of action
38:18is to put in less control force
38:20once that happens
38:21you can have a nice stable flight
38:24so why would an experienced captain
38:26struggle so long to get a plane back under control
38:38long day ahead
38:40don't need this
38:42i pulled the captain's files
38:46investigators turn their attention to the captain of flight 583's training
38:50to determine why he repeatedly over corrected with his control column
38:56he had over 1300 hours on the MD 11
38:58there should be plenty
39:02flew other passenger jets too
39:07the captain had flown the Lucians
39:09he had flown Airbus 300s
39:12he had experience with big aircraft
39:14he had experience with high altitude flight
39:18everything would indicate that he was well qualified to fly the airplane
39:22no complaints
39:25no prior accidents
39:29as clean as a whistle
39:31the captain passed all of his MD 11 training without incident
39:35even took a refresher course a few weeks before the accident flight
39:42let me see the training manual
39:49investigators take a closer look at the training the captain received
39:55a critical aspect of accident investigation when you're looking at an event like this
40:00is pilot training
40:03the captain did go through a very comprehensive textbook or classroom training
40:09find anything?
40:12actually
40:15it's what i didn't find that interests me
40:18no simulator training
40:21none?
40:22nope
40:24not for an inadvertent slot deployment during cruise
40:26or an upset at high altitude
40:32just giving them something to read is sort of like trying to learn to ride a bicycle if you've only
40:38read a manual
40:40what's going on?
40:44with simulator training you get some hands-on training and you have a good idea of what to expect
40:53he did not have that training
40:55he did not have that training
40:56so in fact he was really a test pilot trying to get this airplane back under control
41:01after this uncommanded slot deployment
41:07was there something about the design of the aircraft that made it difficult to regain control?
41:14this is the airbus a300 here and the DC-10
41:17here is our MD-11
41:21when compared to other large passenger jets
41:24one design feature stands out
41:26look at the center of gravity
41:29it's so far aft
41:30most planes have their center of gravity further forward in the midsection
41:36that would make the MD-11 less stable
41:42the MD-11 was designed to increase fuel efficiency
41:47and to do that you move the center of gravity back fairly far aft
41:52the airplane becomes more pitch sensitive
41:58I found the airplane to be very maneuverable
42:01but some people would get a little bit behind it
42:04and you could end up in cases where the airplane would overshoot what you were expecting
42:14investigators conclude that the captain could have stabilized the oscillation sooner
42:18with faster, less forceful control inputs
42:24but the design of the aircraft
42:28made that difficult to do
42:35in their final report
42:37NTSB investigators found that an unintended movement of the slat handle
42:42likely caused the slats to extend and the airplane to pitch up
42:51the probable causes determined by the NTSB
42:55did not place any kind of blame or even talk about the flight crew
43:00actually causing this event
43:03this was a strict design issue
43:07that unfortunately the crew became a victim of
43:15the report also notes that many of the severely injured passengers
43:19either had their seat belts unfastened
43:22or were standing in the aisle
43:28the flight attendants had made an announcement about seat belts
43:32the flight attendants had made an announcement about seat belts
43:32but as is often the case
43:34passengers may have ignored that announcement
43:38and that left many passengers vulnerable
43:44when you are in an airplane
43:46when you are in an airplane
43:47not just for takeoff
43:48not just for landing
43:50it is critical
43:51that you keep your seat belt on
43:55the border
43:55you never know
43:56what can happen in flight
43:58you never know what can happen in flight
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