All language subtitles for Mayday.Air.Disaster.S25E06.Cabin.Chaos.1080p.AMZN.WEB-DL.DDP5.1.H.264-BLOOM_track3_[eng]

After declaring an emergency...

- Injured passengers due
to severe turbulence.

...China Eastern
Airlines Flight 583

seeks permission
to land at a restricted

US military base
in the Bering Sea.

- 300 feet.

- The Pentagon would have
to take a look

at what's happening.

Is this a ruse to take
a look at our radar site?

Once the plane is examined,

officials discount
the possibility of espionage.

- I've never seen anything
like it before.

This accident was definitely

a catastrophic event.

Two passengers died.

The flight data
recorder shows

an erratic flight path.

- Wow.

Being on this airplane was like

being on a rollercoaster.

Only the cause is
not what the pilots reported.

- The weather was clear.

It's unlikely there
was any turbulence.

- That changes everything.

The crew of China
Eastern Airlines Flight 583

is on an overnight flight
from Beijing to Los Angeles.

- Approaching 39 degrees north,
1-72 degrees east.

- All good back there?

In 1993,

China Eastern Airlines was
a fairly new company.

It had only been around
a couple of years.

The entire China aviation
market was rapidly changing.

China Eastern Airlines
began operation in 1988.

It was an exciting time

with people finding that
they suddenly had the ability

to start travelling overseas.

235 passengers
have just finished

their meal service.

Some rest while others
watch a movie.

You press this switch

and the air conditioning
pops up.

The captain
is a veteran pilot

with more than 8,000
flying hours.

- You try.

The captain
was flying the airplane

from the right seat because
he was training the person

who was in the left seat
to be a new captain.

His first officer
is a seasoned pilot,

but new to this plane,
an MD-11.

McDonnell Douglas
developed the MD-11

as a fuel-efficient option
for long-haul flights.

In the early 1990s,

approximately 100 of them
were in service worldwide.

The MD-11 was
an upgraded version

of the DC-10.

It was more efficient flying
at cruise speeds.

Although it had an automated
system for flying the aircraft,

it was also changed
in such a way

that it was very responsive
to pilot input

if they were flying it manually.

This plane is one of five

the airline bought to grow
its international service.

- Fuel check numbers look good.

- Copy that.

During the cruise portion
of the flight,

things are fairly routine.

Flying at 33,000 feet,

the autopilot's on.

They've completed
the first leg of the flight

from Beijing to Shanghai

and are now flying over
the North Pacific,

bound for Los Angeles.

- Ladies and gentlemen.

The cabin crew is now passing
out Customs Declaration Cards,

which must be completed before
entering the United States.

For many passengers,

this is their first
overseas flight.

The process is unfamiliar.

- We're still good at the hotel
we're staying?

- Yeah.

- Something's going on
with the speed indicator.

The crew has pre-programmed

a cruising speed
into the computer,

which is now telling them
to fly at a different speed.

The flight control computer
is making numerous checks

of various systems including
air temperature, airspeed,

fuel burn, etc.

And it sometimes gives
suggestions to the pilots

of how they can fly
more efficiently,

in this case,
fly more slowly.

- Hmm.

That didn't fix it.

The Captain tries to clear

the computer's suggested speed.

It's not a big concern,

the airplane's flying fine.

But it's just odd.

And the captain tries
to sort it out.

- I'm gonna try this.

- What's that?

While they're
sorting out the speed issue...

the plane seems to hit
some turbulence.

They start
feeling this buffeting

and the airplane's
shaking around.

It's definitely something that
will get any pilot's attention.

Suddenly...

...one of the worst things
a pilot can hear:

a stall warning alarm.

I'm taking control.

The nose
of the plane is pitching up,

which shouldn't happen
while cruising

at altitude with
the autopilot on.

He needs
to get the nose down

because if the airplane
truly stalls,

it no longer has enough
lift to stay flying.

It's gonna start dropping
from the sky.

The captain pushes the yoke

with enough force to override
the autopilot...

- Autopilot off.

...and to avoid a stall.

But now the nose pitches
too far down.

The effects of the dive are felt
even more severely in the cabin.

You're trying
to gain control of the airplane,

trying to understand
what's going on.

The adrenalin level goes
dramatic real quick.

The captain
uses all of his strength

to keep the plane from diving,

but the aircraft pitches up
steeper than expected

exerting massive G-forces
on everyone

and everything in the cabin.

- Turbulence!
Seat belts everyone!

- What's going on?

In essence,
this airplane was pitching up

then pitching down.

It's almost like being
on a rollercoaster.

The captain
attempts to level the plane,

but it goes into an even
more extreme dive.

It happened so fast,

the forces are so great,

you wouldn't have time
to even think of trying

to get your seat belt on.

- 8 degrees nose down...

9... 10.

The captain halts
the terrifying dive,

with severe consequences
for unbuckled passengers.

You're being slammed
back into your seat,

and then thrown back
onto whatever might be

below you at the time.

As the plane
is tossed up and down,

the crew avoids a stall
by keeping the nose

from pitching up too much.

But the nose downs
are a problem.

- The pitch downs were more
extreme than the pitch ups

and the aircraft was
losing altitude.

On the next oscillation,

the plane pitches down
an astonishing 24 degrees.

The captain battles to stop
the plane from diving,

while passengers struggle
for their lives.

A lot's going on.

It's a dark night.
He's using his instruments.

Forces are nothing like
he's ever seen before

and so it takes several of
these cycles of this porpoising

until finally he is able to get
the airplane back to level.

30 seconds in,

the oscillations lessen

and the plane begins
to stabilize.

- Level at 0 degrees.

To the crew,
the event probably felt

like it lasted,
you know, an hour.

In reality, it lasted a little
less than a minute.

What just happened?

- No idea.

Even with the autopilot on,

there's no time to relax.

There's no guarantee that what
happened won't happen again.

They're flying over
the vast Pacific Ocean,

nowhere near an airport.

And several passengers
are seriously wounded.

We have many injuries.

- We need to get this plane
on the ground.

Airlines Flight 583): Chn

is back at 33,000 feet.

Now it needs a place to land.

- 235 passengers on board,
unknown number injured.

- Call it in now.

- Flight 583, requesting
the nearest airport,

this is an emergency.

- Airspeed?

298 knots.

- Angle of attack.

- 0.

For now,
everything seems to be working.

All they know
at the moment is the airplane's

flying what appears
to be fine

but, then again,

until we land and get out
and look at it, we don't know.

With injured
passengers on board,

the captain can't take the risk
of flying 37,000 miles

to their destination:
Los Angeles.

- We're 39 degrees North,
1-76 East.

Copy.
Please stand by.

The crew considers
where they might land.

- Are we closer to Russia
or to the US?

This far out
over the Pacific,

mainland Russia is 22,000 miles
to the northwest.

Anchorage, Alaska is the same
distance to the northeast.

They're in one
of the few places in the world

where there's nothing
really close by.

- Ladies and gentlemen.

The plane encountered
severe turbulence

and the damage is
being assessed.

Please cooperate
and be patient.

We are planning for
an emergency landing.

Flight 583 is overseen

by air traffic control
in Honolulu,

2,000 miles away.

What is your emergency?

- Injured passengers due
to severe turbulence.

Stand by please.

It's an unusual situation:

A civilian Chinese airplane

in international airspace
in urgent need of an airport.

Looks like it's
either Anchorage or Shemya.

Waiting for clearance.

Shemya, a tiny
island on the western tip

of Alaska's Aleutian
Island chain,

is about 1,000 miles away.

Anchorage is twice as far.

Because it's an Air Force base,

Shemya has medical staff
and equipment

to treat injured passengers.

Shemya is
basically an island

in the middle of nowhere,

operated by the US Air Force.

It's strictly for
military operation.

There are no commercial flights.

The decision to allow

the China Eastern Airlines
Flight to land

is taken to the highest levels.

The Pentagon
would have to take a look

at what's happening here.

Is this a real emergency,
or is this a ruse

to take a look at our big
radar site we have there?

I imagine there was a lot
of discussion going on

from a security point of view.

Cleared to divert to Shemya.

- We're cleared to divert
to Shemya.

The captain
had a choice to make:

Do I go to the closest
available runway,

which was Shemya, or do I go
further on to Anchorage,

which might be catastrophic

had there been damage
to the aircraft.

- Okay, we're going to Shemya.

We have received permission to
land at Shemya Air Force Base.

Damage to our aircraft
is unknown.

Can we get a weather report?

The crew prepares
for a difficult night landing

on an airstrip they've
never seen before

with unknown damage
to their airplane.

Shemya has extreme weather,

heavy cloud cover, fog
and high winds is the norm.

After a nerve-wracking
two hours in the air,

the plane is now only
40 miles from the air base.

- Altimeters.
- Set.

They really don't know

what's gonna happen
when they slow up.

Did the elevators get damaged?

Will the landing gear come down?

There's a lot of things they've
gotta be concerned about.

As they get closer,
the weather intensifies.

- ILS armed.

Runway 28.

The crew connects
to an Instrument Landing System

that uses radio signals
to guide them in.

- 3,000 feet.

- The crew at this point
is going to be under a good
amount of stress

and pressure to make sure that
they do it right the first time,

wanting to get the people
to help as quickly as possible.

- Autopilot off.

Taking control.

They're now only
6 miles from the runway.

- Gear down.

Landing gear is down.

500 feet.

400 feet.

300 feet.

The ILS gets the plane as far

as 200 feet above the ground.

Then the captain has
to fly by sight.

- We have touchdown.

The emergency is over.

The plane is safely
on the ground.

Medical teams immediately
assess passengers.

The findings are grim.

149 people are injured.

Dozens of passengers and crew
are taken to hospital.

One passenger is dead,

another is fatally wounded.

- This accident was definitely
a catastrophic event.

Many, many passengers
and flight attendants

were seriously injured.

Passengers who are
well enough to travel

are flown to Anchorage
International Airport

and transferred to hospital
for treatment there.

- At that time,
I think I would die.

Of course, surely I would die.

A team of investigators

from the National Transportation
Safety Board,

or NTSB, flies in
from Washington.

Greg Feith leads
the investigation.

You'd never know anything
was wrong with it from here.

They did land on US territory

and so we were gonna conduct
the investigation.

And because it was an MD-11,

it was a relatively
new airplane.

I'll go check inside.

We needed to find out
what really happened.

As soon as
investigators arrive at Shemya,

they inspect the aircraft
for signs of damage.

- I'll go check out the cockpit.

We didn't have a lot
of information.

We knew that there had been
an emergency landing,

that the airplane had
encountered severe turbulence.

With that kind of information,
you can build

a lot of different storylines.

The cockpit looked normal.

But as soon as you looked
down the aisle,

it looked like a bomb
had gone off.

- I've never seen anything
like it before.

- Row 15, bin down
on seats B and C.

Seat 23B,
signs of impact damage.

The cabin gives them
a glimpse into the tragedy

that unfolded during the flight.

There was a lot of baggage

that had come out
of the overheads.

Broken glasses, broken dishes,

they are basically
lethal weapons

if they are flying
through the air.

- Hey.
Check out those marks.

- Likely scuff marks from shoes.

That was really disturbing
because passengers,

they had to have been floating
not only in space

but they had to have rotated

so that their feet
were above their head.

- It seems like there was
a sudden pitch down.

- The damage is worse
in the aft section.

Someone got badly hurt here.

People in the back are more
likely to get injured.

That tail of the airplane
tends to get whipped about

almost like a fishtail.

- Let's see if we can find
some passengers

that are well enough
to talk to us.

We really needed statements
from passengers

and flight attendants who had
experienced the violence.

They were gonna give us
a first-hand account

of what really took place.

Thanks for coming in today.

Okay.

When the incident happened,

what's the first thing
you remember?

- The plane started to shake.

Then it went up and down
like this.

The shaking could be
the result of turbulence.

- How quickly did this happen?

- So fast.

I think I'm lucky to be alive.

- When the plane started
shaking,

did the crew give
a turbulence warning?

- One of the common causes
of turbulence

tends to be bad weather
such as rain or hailstorms.

If the turbulence is unforeseen,

passengers who don't have
their seat belts on

are at much greater
risk for injury.

- Did you see out a window?

Was there any bad weather?

- Not that I could see.

- Thank you.

They described that the flight
was actually relatively smooth.

They didn't notice
any kind of turbulence.

There was nothing unusual
about the flight

leading up to the main event.

Investigators turn
to the weather reports

from the day of the incident.

- This isn't what I expected.

The weather was clear.

It's unlikely there
was any turbulence.

- That changes everything.

- What about the elevators?

- Definitely worth a look.

A damaged elevator could have
led to a loss of control.

We had to determine whether
or not there was a problem.

Elevators are hinged flaps

on the trailing edge of
the horizontal stabilizer.

When the pilot pushes or pulls
on the control column,

the elevators respond
by rising or lowering,

creating pitch.

Investigators look for
any exterior signs

of elevator damage.

Everything looks
good on the outside.

I'll check for internal damage.

We use what's called
the tap test.

And it's a very simple test

and in fact,
it's done with a quarter.

It should sound solid.

If you hear
a hollow type of sound,

that's a very good indication
that there is a delamination

in one or multiple layers
of that composite material.

I'm hearing nothing out
of the ordinary.

After we cleared the elevators,

we still had to understand
what may have caused

this airframe buffet.

No substructure failures
or anomalies were found.

Nothing wrong with
the elevators.

- Then what else?

- What did the captain
have to say?

- I'll check the status
of his interview.

We wanted to know

what he was doing as far
as his duties

and responsibilities
leading up to the upset.

- I'm taking control.

- Hey. You're not
gonna believe this.

Page 22.

NTSB investigators
turn to the captain's account

of China Eastern Airlines Flight
583's high-altitude incident.

- He mentions turbulence before
the onset of the incident.

We knew there wasn't any.
- That's not all. Keep reading.

- He noticed the slats
were extended?

- Yup.

The MD-11 has eight slats

on the leading edge
of each wing.

When extended, they change
the curvature of the wing,

creating more surface area.

Used in tandem with the flaps,

they provide extra lift
during takeoff.

- That's weird.

Why would the slats be
extended during cruise?

Investigators now
have a very promising lead.

There's no reason
to place slats at 33,000 feet.

As soon as you would see that
the slats had extended

at that altitude in cruise,

that would be an alarm bell.

- If the slats were out,

that would explain the pitch up
described by the passengers.

- They're controlled
by this handle here.

- We should check
the entire slat system.

We had to determine whether
one or more of the components

in that slat system had either
malfunctioned or failed.

The first look is clean.

No obvious signs of damage.

We had to access all
the mechanical linkages.

There's hydraulic valves,
electrical mechanical systems,

so we had to make
the determination

whether or not they were
functioning as designed.

Okay, let's test them.

Extend the slats.

There's one handle
in the cockpit

that controls both
the slats and the flaps.

Typically, the slats
are deployed first

so when you pull it back
to the first notch,

the slats get deployed.

You pull it back further;
the flaps get deployed.

- It all seems
to be working fine.

I'm not seeing any mechanical
issues at all.

They examined
the whole system

and they extended normally,
they retracted normally.

There was no obvious damage
to the aircraft.

- I still think the slats
are part of the problem.

- Maybe it wasn't mechanical?

- Good thought.

Maybe it wasn't.

Everything showed
that the airplane

was perfectly fine to fly.

And so the investigation
would focus

to what the pilots did
or did not do

that caused the upset.

Did the pilots
somehow deploy the slats

at high altitude?

- Now we had to determine
whether or not

those slats had been
deployed inadvertently.

You got all the reports?

- Yup.

Have any pilots accidentally

deployed the slat handle
in an MD-11?

They review old
incident reports.

We do what's called
"a look back,"

so we're looking at whether
or not this is an isolated event

or a systemic problem.

- Hey, look at this.

- What have you got?

- 10 incidents in two years.

- Clipboard fell on the handle.

First officer rested
his arm on the handle.

"Slats extended
in cruise flight."

There had been other events
with this particular system,

either an uncommanded

or inadvertent deployment
of the slats.

50% were due to some sort

of pilot contact
with the slat handle.

If the pilot didn't know
he knocked the handle,

he probably didn't
hit it that hard.

- So it could've moved

to the slats only position.

- And deploying the slats
at high speed

would trigger the buffeting,

which was likely misconstrued
as turbulence.

What was happening
in the cockpit

right before the buffeting
started?

- The captain said
he was using

the control keypad,
here.

- They are really close
together.

Investigators
have a new theory;

a simple movement
could have triggered

the entire chain of events.

- We've gotta see how easy it is

to knock this handle
out of place.

Investigators test
whether the crew

of China Eastern
Airlines Flight 583

could have inadvertently
knocked the slat handle

out of position during flight.

- Ready?
- Ready.

It moved.

- Now the first officer was
sitting in the left seat

so he could have knocked it.

But the captain said he was
playing with the keypad.

- They tried different
techniques about, okay,

if you hit the handle
from the right side back,

you hit the handle
from the front side back,

what would it take to jar

the handle out of position?

- Hang on, let me try something.

Bingo. That's what
the captain was doing

when the buffeting started.

- It didn't take
much force either.

It's a major breakthrough.

Proof that the handle could
have been accidentally moved

while the captain reached
for the keypad.

- It was real easy during
normal movement

using the keypad
on the centre pedestal

to inadvertently strike
the handle

and cause an uncommanded
slat deployment.

Investigators
have uncovered

a dangerous design flaw
in the MD-11.

- So the handle probably
moved in flight.

And then the captain
retracted the slats.

The captain said that he saw
that the slat handle

had been out of position
at about the same time

the stall warning system
triggered.

He immediately moved
the slat handle

back into the retract position.

The slats were
fully extended for just seconds.

- Now, that explains
the initial pitch up.

But... there has to be
more to it than that.

I mean, the plane went up
and down several times.

The slats wouldn't
have caused that.

Investigators
still don't understand

why Flight 583 experienced

so many extreme oscillations.

- The cockpit voice recorder
would record for 30 minutes

and overwrite itself,

so we didn't have
that information.

However, with the flight
data recorder,

we could see control positions,

we could gain other information.

Okay, first up,
let's look at pitch.

So we have five big oscillations
in roughly 20 seconds.

The biggest pitch up is here,

oscillation 1,
9.5 degrees.

The biggest pitch down
happens here,

-24 degrees,
oscillation #4.

For the first time,
they can see the severity

of the oscillations
passengers described.

- And it starts
to stabilize... here.

The team launches into
a second-by-second analysis

of the first pitch up.

- The slats were extended here,

during the beginning
of the first pitch up.

- It's gradual at first.

Is the autopilot on?

So it's on for the first
few seconds.

And it would have been fighting
to bring the nose down.

When the slats deploy,
the airplane will have

a natural nose or pitch up
tendency.

With the autopilot engaged,

it will actually correct
for that pitch up

and return the airplane
to a level attitude.

But the autopilot is
losing the battle.

The pitch keeps increasing.

And that would trigger
the stall warning.

Yup, the stall warning
turns on here.

A few seconds later,
the autopilot disengages.

And now the nose dives
down sharply.

- I'm taking control.

Autopilot... off.

- So the captain's
at the controls

when this big drop happens.

Show me the elevator data.

Wow.

So the captain made
some elevator inputs

starting right here.

- That is a huge
nose down command.

- It's an overcorrection.
And I think I know why.

- I'm taking control.

Autopilots are designed

so they won't just
let go easily.

You don't want somebody
just accidentally bumping

against the controls to suddenly
knock the autopilot off.

He felt a resistance

and pushed against
that resistance

of the autopilot,
disengaging it.

Unfortunately, that led
to an excessive amount

of nose down elevator command.

He started a chain reaction
of pushing

and pulling too hard
on the yoke.

At high altitude,

the pitch forces are
very light on the yoke.

So when he pulls back
to get the nose up...

...he's putting in
too much up force.

It goes up too high...

he pitches down,
it goes down too low...

...and he puts in several cycles
on the control yoke

trying to get back to normal.

It's called
a "pilot-induced oscillation,"

or PIO.

The pilot overcorrects,

and the plane responds,

creating increasingly
uncontrollable movements.

Once you get
into the oscillations,
it's hard to stop.

Everything is happening fast.

We were able
to calculate

that the occupants of
the airplane experienced

1.24 negative Gs

and 2 positive Gs.

No wonder there were
so many injuries,

including two fatalities.

He did get the plane
back under control.

It just took a while.

Pilot-induced oscillations

can cause extreme stresses
on the aircraft.

Usually, the best
course of action

is to put in less control force.

Once that happens, you can
have a nice, stable flight.

- So why would an experienced
captain struggle so long

to get a plane
back under control?

Long day ahead.

You're gonna need this.

- I pulled the captain's files.

Investigators turn
their attention to the captain

of Flight 583's training

to determine why he repeatedly
overcorrected

with his control column.

- He had over 13,000 hours
on the MD-11.

That should be plenty.

He flew other passenger
jets too.

The captain
had flown Ilyushins,

he had flown Airbus 300s.

He had experience
on big aircraft,

he had experience with
high-altitude flight.

Everything would indicate
that he was well qualified

to fly the airplane.

- No complaints,

no prior accidents.

He's clean as a whistle.

The captain passed all

of his MD-11 training
without incident.

- Even took a refresher course
a few weeks

before the accident flight.

- Hmm.

Let me see the training manual.

Investigators
take a closer look

at the training
the captain received.

- A critical aspect of
accident investigation

when you're looking at
an event like this

is pilot training.

The captain did go through
a very comprehensive textbook

or classroom training.

- Find anything?

Actually...

it's what I didn't find
that interests me.

No simulator training.

- None?
- Nope.

Not for an inadvertent slat
deployment during cruise

or an upset at high altitude.

- Hmm.

Just giving
them something to read

is sort of like trying
to learn to ride a bicycle

if you've only read a manual.

- What's going on?

With simulator training,

you get some hands-on training

and you have a good idea
of what to expect.

He did not
have that training.

So in fact, he was
really a test pilot

trying to get this airplane
back under control

after this uncommanded
slat deployment.

Was there something
about the design

of the aircraft that made it
difficult to regain control?

- This is the Airbus A300
here, and the DC-10.

Here is our MD-11.

When compared
to other large passenger jets,

one design feature stands out.

- Look at the centre
of gravity.

It's so far aft.

Most planes have
their centre of gravity

further forward,
in the midsection.

- That would make the MD-11

less stable.

The MD-11 was designed

to increase fuel efficiency.

And to do that, you move
the centre of gravity

back fairly far aft.

The airplane becomes
more pitch sensitive.

I found the airplane

to be very maneuverable.

But some people would get
a little bit behind it

and you could end up in cases

where the airplane
would overshoot

what you were expecting.

Investigators
conclude that the captain

could have stabilized
the oscillations sooner

with faster, less forceful
control inputs.

But the design of the aircraft
m

made that difficult to do.

In their final report,

NTSB investigators found that
an unintended movement

of the slat handle likely
caused the slats

to extend and the airplane
to pitch up.

The probable cause,
as determined by the NTSB,

did not place any kind of blame,

or even talk about
the flight crew

actually causing this event.

This was a strict
design issue that,

unfortunately,
the crew became a victim of.

The report
also notes that many

of the severely injured
passengers either had

their seat belts unfastened

or were standing in the aisle.

The flight
attendants had made

an announcement
about seat belts,

but as is often the case,

passengers may have ignored
that announcement.

And that left
many passengers vulnerable.

When you are in an airplane,

not just for takeoff,
not just for landing,

it is critical that you keep
your seat belt on.

You never know what can
happen in flight.

Subtitling: difuze