All language subtitles for Air.Disasters.S04E07.Catastrophe.at.OHare.1080p.PMTP.WEB-DL.AAC2.0.H.264-maldini_track3_[eng]

NARRATOR: In 1979, chaos
when the FAA grounds

every DC-10 in America.

You can imagine if one of
your real workhorse airplanes

is grounded, it's a
terrible situation.

NARRATOR: The reason.

Look at this.

NARRATOR: American
Airlines Flight 191.

- I'm losing it.
- Go right.

Go right.
Come on.

Come on.

It only got about 300
feet above the ground.

What do you got?

NARRATOR: As investigators
search for evidence.

It's one of the
bushing bolts.

NARRATOR: In the worst air
disaster in US history.

Split right in two.

There's the bolt. This
is a fracture point.

NARRATOR: They face
intense media pressure

to identify the cause.

Some very crucial
photographs showed the aircraft

on its final, fatal plunge.

NARRATOR: The shocking
images may finally explain.

We need to see those slabs.

NARRATOR: Why 271
people died seconds

after leaving the ground.

WOMAN 1: and gentlemen, we
are starting our approach.

MAN 1: We lost both engines.

Emergency descent.
MAN 2: Mayday.

Mayday.

WOMAN 2: Brace for impact.

MAN 3: He's gonna crash.

Any updates on the weather?

Surface wind 20
degrees at 22 knots.

Nothing but blue skies.

NARRATOR: On a
Friday afternoon,

the seasoned crew of
American Airlines Flight 191.

Rudder set.

NARRATOR: Makes final
preparations for takeoff.

Spoilers.

Armed.

NARRATOR: From Chicago's
O'Hare Airport.

Captain Walter
Lux was scheduled

to have the weekend off, but
is covering for a friend.

This crew was a
very experienced crew.

The captain had
approximately 22,000 hours

of flying time, of which about
3,000 hours were in the DC-10.

So he was a very,
very experienced

pilot in the aircraft.

NARRATOR: The DC-10's
three-engine layout

makes it one of the
most recognizable

passenger jets on the runway.

They're being flown by
almost every major airline.

The DC-10 was a
very popular airplane.

It was one of the
first jumbo jets.

So the airlines were able
to put twice as many people

on board the airplane
and only feed

three engines instead of four.

So it was much more
economical for them

because they could
eliminate a lot of flights

and still carry the same
number of passengers.

American 191, good afternoon.

Taxiing to position
on runway 32.

Right and hold.

American 191, thank you.

Taxi and hold, runway 32 right.

Flaps and slats to 10.

Takeoff and
landing are the most

crucial and most difficult and
busiest times in the cockpit.

NARRATOR: It's the Friday
before Memorial Day.

There are 258
passengers on board

for the flight to Los Angeles.

On this flight, a live feed
from a video camera mounted

in the cockpit allows
passengers to watch

the takeoff from the cabin.

It's a new feature
for American Airlines.

It was simply showing
the runway and what

the pilots were
seeing as you took off

or as you came
in for a landing.

So it was just like a
movie for the passengers.

American 191, you are
cleared for takeoff.

American 191, underway.

You have control.

I have control.

Runway clear?

Clear.

OK.

Setting takeoff thrust.

Here we go.

Replied takeoff power.

You've got three engines
pushing you down the runway.

NARRATOR: Sharing the
pilot's view from the cockpit

is a thrill for many on board.

At 3:04 PM, the plane is
seconds away from lifting off.

V1.

You accelerate
to V1, which is

the speed beyond which you can
no longer abort the takeoff.

So you have to keep going.

You have to take off
no matter what happens.

Rotate.

A few seconds later,
you reach rotation speed.

This is when the pilot
would lift the nose.

The front wheel would
come off the runway.

Damn.

There's the turbulence.

Not too rough.

Did you see that?

I've lost power to my sight.

NARRATOR: The captain's
instruments suddenly go dead.

It looks like we've
lost number one.

NARRATOR: And he's lost
power from the left engine,

but the plane is
already airborne.

You have to keep going.

You have to climb out.

And if there's something
wrong with the airplane,

even if the problems
are critical,

your best hope
is to keep going,

to climb, contact
ATC, and come around

and land somehow, somewhere.

Look at this.

Look at this.

Equipment.

I need equipment.

He blew an engine.

NARRATOR: The DC-10
should be able to climb

with only two engines.

These multi-engine planes are
specifically designed to take

off with one engine out.

They're designed to climb
out at a brisk rate of speed

and to climb to a
safe altitude with one

of the engines missing.

NARRATOR: Pilots
are trained to cope

with this kind of emergency.

First, they need to get as far
from the ground as they can.

Altitude is critical.

There's a saying
that pilots have.

The three things you
need are altitude,

airspeed, and an idea.

NARRATOR: They put their
plane into a steeper climb.

Forward speed drops.

If you have
room to play with,

if you have the
altitude, now you

can look around and try to
figure out what went wrong

and try to institute
some corrective measures.

American 191, heavy.

You want to come back?

And to what runway?

- We're banking.
- Go right.

Go right.

NARRATOR: The plane is
banking sharply to the left.

It's only 325 feet
from the ground.

They were applying full right
aileron because the left wing

was going down.

And by applying full right
aileron, what you're doing

is trying to lift that wing
back up that has gone down.

You might try to turn the
ailerons the other way harder.

And if that still doesn't work,
something's clearly wrong.

I can't hold it.

American 191, heavy.

Do you copy?

He's not talking to me.

NARRATOR: Losing
power from one engine

should not be causing
the plane to bank.

Passengers have a frightening
view of the ground below.

What's going on?

NARRATOR: The pilots can't
get the altitude they need,

and they're banking further
and further to the left.

- I'm losing it.
- Go right.

Go right.

Come on.

Come on.

300 feet.

We're losing altitude.

NARRATOR: The cockpit
camera gives passengers

a glimpse of their fate.

But they are not the only ones
whose lives are in danger.

A trailer park just
north of the airport

is home to thousands of people.

Oh, God.

NARRATOR: And the plane is
heading straight for it.

Witnesses on the
ground can clearly see

Flight 191 flying on its side.

We're still turning.

Level, baby.

Level.

Brace, brace, brace.

Brace, brace, brace.

Well, certainly it would
be a very, very scary thing.

And you would certainly know
that you were about to die.

We're losing it.
Go right.

Go right.

Go right.

There he goes.

The DC-10 crashes
into an airport hangar

at the edge of the airport.

The full load of fuel
instantly ignites.

DC-10 with 271 souls
on board has gone down

northwest of runway 32 right.

It only got about 300
feet above the ground.

And it traveled maybe
4,600 feet or so

beyond the end of
the runway before it

crashed into a field.

As soon as we pulled
out of the station,

we could see the
column of smoke.

And of course, as we got closer
and closer, it was heavier.

And you could see
how big the site was.

NARRATOR: Less than a
minute after takeoff,

there was almost nothing
left of Flight 191.

Everything was smoldering.

And I remember seeing
pieces of the aircraft

that were very recognizable,
such as the landing gear.

And I remember seeing
one of the engines also.

NARRATOR: Rescuers find
a horrifying scene.

We saw-- what was
recognizable is torsos,

body parts.

It just brought back
the human element.

And you realized and
thought about the people

who were on board.

NARRATOR: As they begin
assessing the full scope

of the disaster,
they have very little

hope that anyone survived.

American Airlines
Flight 191 has crashed

just short of the trailer
park beside Chicago's

O'Hare Airport.

The DC-10 has also obliterated
a hangar beyond the runway.

There were some
distinct odors.

Jet fuel.

Certainly, that was
the overpowering odor.

And then the eerie
quiet I remember.

NARRATOR: Once the
fire is under control,

the search for
survivors can begin.

But as you walk
the scene, it was

pretty obvious pretty quickly
that there were no survivors.

It was very, very frustrating
to realize that no matter

what your training was,
there was nobody there

that you could help.

NARRATOR: All 271 people
on board are dead.

Two workers inside the
hangar have also been killed.

It's the worst aviation
disaster in US history.

A lot of people
saw this happen.

Let's see what
they can tell us.

NARRATOR: The National
Transportation

Safety Board must
now figure out

what went wrong on Flight 191.

REPORTER: This is a Breaking
News Special Report.

Good evening.

An American Airlines DC-10
crashed just after takeoff

this afternoon from Chicago's
O'Hare International Airport.

This is the kind of accident
which unfortunately really

grabs the imagination
of the public

and can do so much
to cast a stain

on the reputation of an
airline, of an aircraft,

on air travel in general.

NARRATOR: Thousands of people
fly aboard DC-10s every day.

If there's a flaw in the plane,
investigators need to find it

before more people are killed.

The stakes were
very high for the NTSB

to get this
investigation right.

The airlines wanted the public
to understand that this was

fundamentally a safe aircraft.

NARRATOR: They
are eager to hear

from the many people who
saw the crash, especially

those with the best view.

Controllers in the tower.

Look at this.

Look at this.

NARRATOR: The
controllers revealed

that Flight 191's left
engine didn't simply fail.

The engine fell off the plane
just after they lifted off.

I saw it fall.

If you were sitting
on the left hand

side of the airplane,
what you would have seen

was the number one
engine on the left side

rotated up, and flipped back,
and disappeared behind you.

Did you see that?

That's the last
thing an airline

passenger wants to see.

These engines are
actually designed

to go back up over the
wing in case of failure,

so that they will miss
the tail as they go by

and not cause damage
to the tail section.

They will go over the tail.

NARRATOR: The engine has landed
nearly 2,500 feet from the end

of runway 32 right.

The team scours the
tarmac for any pieces

that came from the plane.

How does a DC-10
lose an engine?

NARRATOR: The smallest
piece of evidence

can be of vital importance.

I've never seen
anything like this.

That is not
supposed to happen.

The engineering is
supposed to be so robust

that that will not occur.

So when that happens, you'll
have the undivided attention

of everybody involved
in the investigation

because that's a big deal.

NARRATOR: In the entire
history of commercial aviation,

there have only been a
handful of similar incidents.

But concerns over the safety
of the DC-10 are not new.

This is the third major
accident for the plane

in the last five years.

There were a series
of fatal accidents

that were very high
profile in the news.

And the name DC-10
kept appearing time

and again in headlines led
the public to wonder what was

going on with this airplane.

NARRATOR: In 1972,
American Airlines Flight 96

lost its rear
cargo door shortly

after takeoff from Detroit.

The DC-10 was at
almost 12,000 feet

when the door blew out, causing
an explosive decompression

that severed essential
control cables.

The pilots were able to
make a successful emergency

landing, saving all on board.

Two years later, the 346
people aboard Turkish Airlines

Flight 981 were not so lucky.

They all died when
their DC-10 crashed

into a forest in
France after suffering

a similar cargo door failure.

Public confidence
in the airplane

was fairly low at this point.

And a lot of people would
not fly on that airplane.

They would book another trip
or book another airline to stay

away from the airplane.

They say if it's a DC-10,
put me on another flight.

I don't particularly
like flying DC-10s,

but you know, it's the
only flight we can take,

so we take it.

NARRATOR: Investigators
desperately

need to know how
an engine fell off

a plane carrying 271 people.

They searched the charred
debris for the plane's

flight recorders.

You've got a plane that
is destroyed on impact

as this plane was, the
data from the recorders

can be essential because that
really is your only source

of information.

NARRATOR: The team is able
to recover both black boxes.

But the recorders
are heavily damaged,

it will take time
to analyze the data.

What you got?

NARRATOR: The
investigative team

soon makes another discovery.

It's one of the
bushing bolts.

Split right in two.

NARRATOR: It could
prove to be crucial.

They found a bolt
that had broken.

And the question
that was raised

was did this bolt break before
the accident and cause it,

or did it break as a
result of the accident?

NARRATOR: The left and
right engines of a DC-10

are mounted to the
wings through a rigging

system known as the pylon.

The bolt found on the
runway is one of the few

holding it in place.

The badly damaged
bolt was found

closer to the start
of the runway,

suggesting that it may
have been the first thing

to come off the plane.

So what do you think?

NARRATOR: The
investigative team believes

they have found the culprit.

This would explain it.

NARRATOR: The NTSB is
under immense pressure

to explain how an engine
could simply fall off

a widely used passenger jet.

Two days after the
crash, they hold

a news conference to announce
that they found the cause.

A broken bolt.

There is the
bolt. There is a nut

still attached to
part of the bolt.

This is the fracture point.

Well, I arrived at the
scene of the investigation.

And it was a press
conference going

on at that time, in which the
vice-chairman of the Safety

Board was speaking.

And he had just concluded.

NARRATOR: Michael Marks is a
metallurgist with the NTSB.

What did you guys
say about the bolt?

We said this is it.

This is why the
engine came off.

NARRATOR: He's an expert
in fractures and failures

of airplane parts.

It was related to me that he
had indicated that a bolt that

was found on the
runway was involved

in the engine separation.

Tell me you have more
evidence than that.

When I visually looked at
it, I could see nothing

on the bolt that would
indicate anything out

of the ordinary, which
all I could do is say,

this bolt didn't have any
preexisting cracking on it

or have anything that
would indicate that it had

a weakness in the structure.

This thing broke when it
hit the runway, not before.

So not exactly
our smoking gun.

We need more information.

And to announce
that you basically

have some kind of cause
for that engine separation

without really
looking at it, it

was not a good idea
to come out with this

at that particular time.

And so more caution was needed.

OK, look.

We've got to forget
about the media

and focus on the evidence.

It turned out that it
didn't cause the accident.

But going in, you
don't know what

is going to turn
out to be important

and what's just a red herring.

NARRATOR: The confusion
at the press conference

only increases the pressure.

There is no room for
any more mistakes.

For now, the team can only
study the wreckage for clues.

They hope there is
enough left to the plane

to help them make
sense of what happened.

Hold on, let me see that.

OK.

Good.

Anything from the main
crash site goes over here.

Anything from the runway,
any engine or wing parts,

goes to that side.

Well, my first
priorities would

be to look at the actual
parts, the actual separation.

Where is it that
this thing broke?

This is definitely
part of the pylon.

I've never seen
one break like that.

NARRATOR: The pylons are
mounted under the wings.

Each one is strong
enough to suspend

an 11,600-pound engine.

The pylon is designed very
well, I mean, strength-wise.

So it basically could
take a lot of load.

Much more load than you would
normally see in the course

of the airplane life.

NARRATOR: The pylon
gets its strength

from two internal bulkheads.

One forward and one aft.

These bulkheads also provide
secure points of attachment,

ensuring that the engines are
firmly fixed to the wings.

It's also designed
to have multiple load

paths, so that it's what
they call failsafe design.

NARRATOR: It seems
incredible that a pylon,

one of the strongest parts of
the plane, could have broken.

Conceivably, the failsafe
design is flawed.

If so, it could just
be a matter of time

before another pylon
breaks in mid-air.

Any idea what happened to it?

I need to see the
rest of the pylon.

NARRATOR: As some investigators
search the wreckage

near the airport for the
rest of the broken pylon,

others are finally
able to listen

to the cockpit voice recorder.

It should reveal
if the pilot had

any indications of a problem
as they were taking off.

OK.

Go ahead.

PILOT: American 191, thank you.

Taxi and hold, runway 32 right.

Flaps and slats to 10.

NARRATOR: The taxi and takeoff
rule are perfectly routine.

American 191 underway.

NARRATOR: There is no
indication the pilots

were having any problems.

PILOT: OK.

Setting takeoff thrust.

Here we go.

Sounds pretty routine so far.

PILOT: V1, rotate.

Damn.

Is that it?

Well, the tricky things
about this accident

for investigators was that
the nature of the damage

was such that the cockpit
voice recorder itself

was rendered inoperable.

So that was a big
loss of clues.

NARRATOR: The
voice recorder was

powered by the left engine.

Damn.

NARRATOR: Once it fell
off, the recording stopped.

Thanks.

About the last thing they
heard on there was just damn.

And that was the end
of the recording.

And that told them
absolutely nothing.

NARRATOR: They may never know
what happened in the cockpit

after the engine fell off.

The flight data recorder
is also nearly useless.

Because of the extreme
way the plane was flying,

a lot of the data
makes no sense.

This isn't going to help us.

NARRATOR: At the hangar,
there has been some progress.

Investigators have recovered
all the pieces of the pylon.

Michael Marks may now be
a step closer to figuring

out why it broke apart.

Now I had an indication that
maybe this is the area that we

really should be looking at.

So in doing that, you
needed to get more

detailed inspections of it.

You needed to get
it to the laboratory

back in Washington, DC.

NARRATOR: Investigators also
examine the plane's history

for anything that might relate
to this catastrophic failure.

John Goglia spent nine years
as a senior maintenance expert

for the NTSB.

Instantly, if we know we
had an engine falling off,

you're going to go right
for the maintenance records.

You're going to go right to
the history of the airplane.

They had the engine
out at the end of March.

NARRATOR: Eight weeks before
the accident, the left engine

was removed for servicing.

Any time that you
have an airplane that's

been into maintenance just
before a crash, that raises

all sorts of warning flags.

All sorts.

Let's go down to Tulsa.

See what they did.

If you have an investigation
that involves maintenance,

if you don't go
inside the hangar,

you don't follow
that trail, you're

going to miss some issues.

NARRATOR: Why the pylon broke
is not the only question

that needs to be answered.

Damn.

I've lost power to my sight.

Looks like we've
lost number one.

NARRATOR: Two of the DC-10's
three engines kept working.

The plane had the power
it needed to keep climbing

and then get back
to the airport.

In fact, you could lose a
second engine shortly after

lift-off and you
would still be able

to power the aircraft around.

NARRATOR: But somehow,
experienced pilots

weren't able to fly this plane
after losing just one engine.

With 270 people dead after
an engine fell off a plane,

the FAA makes a
drastic decision.

On June 6th 1979, the
agency grounds every DC-10

in the United States.

138 planes in total.

Well, you can imagine if
one of your real workhorse

airplanes is grounded,
disrupting flights,

inconveniencing passengers,
generating headlines,

it's a terrible situation.

You spend $100
million for an airplane,

you can't leave it
sitting around very long.

It's costing you a lot of
money every day to have

that airplane on the ground.

NARRATOR: All foreign-based
DC-10s are banned

from entering us airspace.

The pressure on
investigators mounts

as the effects of America's
worst air disaster

spread across the globe.

Investigator Michael Marks
believes the shattered pieces

from the engine
pylon may explain why

Flight 191 fell from the sky.

Hey, look for yourself.

Did that had to happen
before the crash?

I just don't know why.

We're looking at that
bulkhead in detail.

There was one very
puzzling thing.

NARRATOR: A close
examination reveals

a crack in the
metal that clearly

developed slowly over time.

It's a telltale sign that the
pylon bulkhead was already

damaged before the crash.

You can see where it's
spread, all along there.

NARRATOR: The
crack that Michael

Marks finds runs along the
top edge of the aft bulkhead.

The cracks were consistent
with a fatigue phenomenon

or a cyclic behavior, a crack
extending from repeated loads.

Each time the load
occurs, you then have

an extension of the crack.

NARRATOR: The
microscopic examination

gives Marks another clue.

A dent on the pylon bulkhead
at exactly the point

where the crack began.

There was also
a deformation that

was on one of the fractures.

At that time, I was
not absolutely sure

what it all meant because it
just showed a deformation.

It looks like something
hit the pylon.

I'm just not sure what or when.

OK.

I'll see what I can find.

Take notes on everything.

Got it.

The information is available.

It's on the hangar floor.

It's in the minds
of those people.

We just have to ferret it out.

NARRATOR:
Investigators arranged

to watch as another DC-10
undergoes the same maintenance

that was performed
on Flight 191

just weeks before the crash.

Can you take me up and show
me how the engines mount?

We're going to talk
to the people involved.

Most likely, it's going to
be the maintenance personnel.

And we're going to ask
them pointed questions

on what have you done?

Have you done this job before?

What kind of problems
did you encounter?

Did you follow the
paperwork to the letter

religiously, step one,
step two, step three?

They found procedures that
were not in the manual.

They found procedures
that the manufacturer

didn't recommend be performed.

NARRATOR: To save time,
the airline has modified

a key maintenance procedure.

OK.

Bring her up.

A wing mounted engine on a
DC-10 as a 24-hour adventure,

which is extremely long.

So there's a lot of
pressure on getting

whatever is broken
repaired and getting

the airplane back in the sky.

NARRATOR: The normal
procedure for servicing

an engine involves
removing it from the pylon

and leaving the pylon
attached to the wing.

There are hundreds of
connections to be undone.

Procedures from the
manufacturer would deem to be

too time-consuming, and
they could do it faster,

better, cheaper.

So they were deviating
from the procedures.

NARRATOR: The
quicker way involves

taking out just three bolts.

The engine is removed
from the wing while still

attached to the pylon.

It saves about 200
man hours of labor.

It was easier.

The attach points from
the pylon to the wing

were accessible.

The attach points from
the engine to the pylon

were much more
difficult to take

apart and put back together.

Removing is not the issue.

It's the attempt to reinstall--
- Whoa.

Stop

Is where the
problem comes from.

Left a bit.

Now up.

NARRATOR: Maneuvering
the pylon into position

with an engine attached to
it is a tricky procedure.

Trying to put the engine
in the pylon back together,

some 13,000 pounds
for the engine

and 2,000 pounds for the
pylon, it's not easy.

They were using the forklift.

And this forklift is
not very manageable.

It cannot be finely
controlled as far

as the altitude is concerned.

The minimum movement
on the forklift

was something on the order
of a quarter of an inch.

And we're talking about
trying to fit something

together that might
be in the order

of thousandths of an inch.

Whoa, stop.

Stop.

So you get just
slightly the wrong angle,

and you get too
much pressure on it,

and you're going to
crack those fittings.

I'm sure they didn't
realize how quickly

they could get in trouble doing
it the way they were doing it.

I think I know what happened.

NARRATOR: A possible
explanation surfaces--

Take her down.

NARRATOR: For the
mysterious dent found

on the pylon from Flight 191.

The team in Tulsa calls Marks.

What you got?

NARRATOR: They describe how
the maintenance crew struggled

to fit the pylon attachment
into the mounting bracket

or clevis.

And then it all
came together,

just like a bolt of lightning.

The clevis itself had
produced this deformation

that was on the fracture.

NARRATOR: Marks concludes
that on the accident plane,

the clevis must have
slammed into the top

of the pylon bulkhead as the
engine was being reattached.

The impact could have
started the crack

that led to the pylon's failure
and to the crash itself.

The maintenance people
that did this operation which

cracked the pylon
probably didn't

hear anything, a bang or
crack or anything like that.

OK.

Bring her up.

We call it working around.

So they worked
around the manual

to get the job done quicker.

But the process never gets the
proper vetting, if you will.

Review from engineering
and from the manufacturer.

And sometimes, those
alternate methods

have unintended consequences.

NARRATOR: Over the
next eight weeks,

each time the plane
took off, the stress

that the massive
engine put on the pylon

made the crash grow larger.

The engine is not only
imparting a thrust load,

but it's also imparting
a sideways load.

So each time you
have this load,

it breaks a little bit
more, and more, and more.

NARRATOR: It was
only a matter of time

before the pylon snapped,
and the engine fell off.

So the process was
flawed, and the people

made adjustments
to a flawed process

to try to make it work.

And collectively, that
is a recipe for disaster.

How long have
you been putting

the engines on this way?

Not sure, but every
airline does it.

NARRATOR: Even more
worrying, the mechanics

at American Airlines are not
the only ones cutting corners.

The airlines
shared processes.

And since this
engine change was

so time-consuming and
costly, they were all looking

for a better way of doing it.

Faster, better,
cheaper way to do it.

And so when one
would discover it,

a process to use
that maybe made

the engine change go
quicker, the others

were very quick to adopt it.

And that's exactly
what we see here.

We need to get the entire
fleet inspected for this.

NARRATOR: It is now
clear why the engine fell

from the plane,
but what happened

after that is still a mystery.

Flight 191 could
have landed safely

with one missing engine.

Instead, 273 people died
in a horrific crash.

The plane was
completely flyable.

It was in bad shape.

It had lost an engine.

It had lost several
critical systems.

But it was still airworthy.

And it was still able to fly.

What happened
in that cockpit?

NARRATOR: The
crash of Flight 191

has a devastating effect on
the entire airline industry.

It was a huge economic
problem for the airlines

because their major airplane
was now on the ground,

and they couldn't fly it.

And of course, I think it had
a big impact on the public

as well.

Have you seen this?

NARRATOR: So why
weren't the pilots

able to save their plane
after losing one engine?

A chance photograph taken
just before the crash

may provide some answers.

There was certainly one very
famous photograph that was

published in many
newspapers of the aircraft

in semi-inverted
position, almost

ready to strike the ground.

Everyone saw this picture.

I want you to track down
all the pictures you can

and get them blown up.

I want to see those wings.

You got it.

These photographs that can do
so much to horrify the public

can have a real use for
the accident investigators.

NARRATOR: By examining
photographs taken just prior

to the crash, they
might be able to tell

whether the pilots made some
mistake when they configured

their plane for takeoff.

Flaps and ailerons look fine.

By blowing up and
zooming in on the leading

edge of the wing, the
aircraft investigators

were able to determine
what was going on.

Is that hydraulic fluid?

NARRATOR: If the fluid
leaked from the plane's

hydraulic system, it might
explain why the plane

was so hard to control.

Sometimes, the crucial
element in air crash

investigation can
be some very small,

subtle detail from which
everything else can devolve.

NARRATOR: Several of the
DC-10's hydraulic lines

run along the leading
edge of the wing.

Take a look at this.

NARRATOR: It's the area
that was damaged the most

when the engine broke free.

We need to see those slats.

American 191, thank you.

Taxi and hold runway 32 right.

Flaps and slats to 10.

NARRATOR: The plane's slats
are extended before takeoff.

They're essential for
providing the lift needed

to get the plane airborne.

The slats are on the
leading edge of the wing.

And when you deploy the
slats, they move out forward.

So the air has a
longer distance to go

and therefore,
is moving faster.

And it creates more of a
lift a vacuum above the wing.

NARRATOR: If the hydraulic
system controlling the slats

failed, it could explain
the plane's loss of control.

Investigators discover
that while all the slats

in the right wing were
extended for takeoff,

some on the left wing were not.

It's a configuration
that's normally impossible.

You have one
wing that is flying

and the other wing that isn't.

And when you have a
wing that's flying

and one that isn't, the
one that isn't flying dips,

and the one that is
flying continues to fly,

which means the airplane
goes into a roll.

NARRATOR: They conclude
that the engine

hit the wing with
enough force to rupture

the hydraulic lines.

The fluid keeping the slats
extended on the left wing

would have drained quickly.

I can't hold it.

NARRATOR: Without fluid,
some slats on the left wing

retracted, causing
that wing to lose lift.

The plane began to roll.

The actual stalling
speed was 124

knots for the airplane at
this weight and configuration.

I'm losing it.

The fact that the
slat had retracted

raised the stalling speed
to 159 knots from 124 knots.

So it was a huge difference.

NARRATOR: Without
the slats, they

needed to be flying much faster
than normal to avoid stalling.

One final question remains.

Why couldn't the pilots
recover from the stalled wing?

Investigators recreate the
takeoff in a flight simulator

to find out.

OK, you all set?

We're ready.

Let's try one.

V1.

This crew had almost 5,000
hours in this aircraft.

You couldn't ask for
a more experienced

crew in this airplane.

And if anybody was
going to be able to fly

that airplane in
that condition,

it would have been this crew.

NARRATOR: Immediately
after the slats retract,

there are dramatic
warnings in the cockpit.

There is a stall
warning system

that will advise the
pilots when the airplane is

about to stall.

It's called a stick shaker.

And when you're nearing
the stall speed,

your stick will actually start
to shake to warn you of this.

NARRATOR: The stick shaker does
exactly as the name suggests.

It vibrates the control column
to get the pilot's attention.

If you get a stall warning,
you obviously lower the nose,

and you apply for power, and
you fly it out of the stall.

If they had lowered the nose,
let the airspeed increase,

they actually would
have been fine.

The plane was recoverable.

It was landable.

NARRATOR: The
simulator tests show

that once the pilots are
alerted to the problem,

it is possible to recover.

Why didn't they do that?

NARRATOR: If the
pilots on flight 191

had known they were
stalling, they could have

been able to save their plane.

It seems possible that
somehow, they didn't know.

Investigators study the cockpit
warning system on the DC-10

and make a crucial discovery.

All the alarms are
powered by the left engine.

When the engine fell off,
it severed hydraulic systems.

It severed electrical systems.

I've lost power to my sight.

Looks like we've
lost number one.

It resulted in a
loss of instrumentation

and of warning devices.

NARRATOR: As soon as the
left engine came off,

the warnings that could have
saved the plane were disabled.

They bring in a new test
pilot to fly the simulation.

OK.
You're all set?

NARRATOR: What they
don't tell him--

We're ready.
Let's try one.

NARRATOR: Is that
all the warnings

have been disconnected.

From that position
in the cockpit,

you can't see that left wing.

And they didn't even know
the engine was actually gone.

They thought it
had just stopped.

It looks like we've
lost number one.

When pilots say lose an engine,
we mean we lose engine power.

This plane actually
lost an engine.

NARRATOR: Without
warnings, the test

pilot is in the same plight
as the American Airlines crew.

He has no idea his
plane has stalled.

If the stick shaker
stall warning device

had been functioning,
it's very easy

to imagine that the
pilot flying the airplane

would have put the
nose down and would

have avoided a stall.

- We're banking.
- Go right.

Go right.

NARRATOR: Since they don't
know about the stall,

they follow the procedure for
an engine failure on takeoff.

It sealed their fate.

Pilots were taught
at that point in time

that if you lost an
engine, the whole idea

was to get more altitude faster
and get away from the ground.

So if you lost a second engine,
you would have that much

more altitude to play with.

And so you were taught
to pull back on the wheel

and go back to the
minimum safe flying speed

to get away from the ground.

Reduce speed 153 knots.

Reducing speed to 153 knots.

NARRATOR: Reducing speed
by lifting the nose

is the exact opposite of
what pilots need to do when

a plane is about to stall.

It makes the stall worse
and the roll more severe.

Following the checklist
for a single engine failure

made what happened next
inevitable and doomed everyone

on board.

If they didn't know
they were stalling,

they didn't stand a chance.

The pilots flew
the plane exactly

as they'd been trained to
do, exactly as procedure

demanded that they fly it.

The pilots were doing
absolutely the right thing.

There was absolutely nothing
that he could have done.

He was powerless.

He was along for the ride.

NARRATOR: The NTSB concludes
the pilots were not at fault.

They do, however, fault
American Airlines' maintenance

practices and the FAA for not
enforcing proper procedures.

The FAA mandates that
stick shakers be installed

on both pilots' control
columns and that the warning

system be powered by
more than one engine.

The plane's hydraulics are also
redesigned with special plugs

to prevent slats and
other control surfaces

from retracting if
the lines are cut.

When the airplanes
were grounded

as a result of
this accident, we

found a number of
other airplanes

with cracks in the fleet.

NARRATOR: Inspectors
find eight more

DC-10s with damaged pylons.

It was very scary when the
inspections uncovered so many

other airplanes with problems.

That was very, very scary.

Because every one of
those had the potential

of being another accident.

And had we not
done the grounding,

then we may have had
yet another accident

before we realized the width
and breadth of the problem.

This kind of action
never happened again.

This engine never fell off
this kind of airplane again.

In the general sense
though, it teaches us

how to look at safety.

It teaches us how to
look at the culture

of training and procedures
in the air and procedures

on the ground.
- Whoa.

Stop.

Stop.

NARRATOR: One final outcome
of the Flight 191 disaster?

Airlines reconsidered the
idea of sending live video

to passengers in the cabin.

The passengers were able
to see the airplane going

into this dive and
were able to see

their own demise in effect.

NARRATOR: The cockpit
camera was abandoned.

But the shocking photo of
Flight 191's last

moments remains.

An image that both the airlines
and the FAA likely wish

could be erased.

They would much rather have
people think of air travel

as cramped seats, bad
food, luggage being lost,

than with dying.

Luggage being lost will
make people grumble,

but people dying will
make people not fly.