All language subtitles for Air.Disasters.S20E17.Death.from.Above.1080p.SMIT.WEB-DL.AAC2.0.H.264-maldini_track3_[eng]

[music playing]

GROUND CONTROL:
Gentlemen, you look good.

Gentlemen, you have a race.

NARRATOR: A thrilling
day at the air show

turns into a nightmare for
spectators on the ground.

He's coming right at us!

[screams]

By the time they
got to the point of,

oh my God, this is
headed right for us,

it was too late to move.

NARRATOR: A plane spirals into
the center of Mexico City.

I remember thinking
that, well, this is it.

This is it for me.

[screams]

NARRATOR: The out-of-control jet
sets the financial core ablaze.

It was disaster for a lot of
innocent people on the ground.

NARRATOR: A DC-9 plummets into
a Los Angeles suburb destroying

a residential neighborhood.

When you've got an airplane
that falls out of the sky

and hurts or kills
somebody on the ground

who's just innocently
there, there is

a heightened level of concern.

Three

NARRATOR: Flights gone wrong
reign terror from the sky.

FLIGHT ATTENDANT:
Ladies and gentlemen,

we are starting our approach.

PILOT: We lost both engines.

FLIGHT ATTENDANT: Put
the mask over your nose.

Emergency--

PILOT: Mayday.

Mayday.

FLIGHT ATTENDANT:
Brace for impact!

[muffled speech]

He's gonna crash!

[music playing]

NARRATOR: Reno,
Nevada, is hosting

a high-stakes competition
known as the National

Championship Air Races.

The Reno Air
Races are all about

one thing and only one thing,
and that's all-out speed.

NARRATOR: 100,000 spectators
converge on the site

to watch everything
from biplanes to jets

race around an eight-mile oval.

[music playing]

The highlight of the event is
the unlimited class, unlimited

because there are no
limits on how World War

II fighters can be customized.

ROBERT "HOOT" GIBSON:
Many of the airplanes

have been highly modified
just to make them go faster.

NARRATOR: The course is
marked by 10 50-foot pylons

planted in the desert.

The finish line is directly
in front of the grandstand.

Pilot Jimmy Leeward is competing
with his legendary highly

modified P-51 Mustang,
the Galloping Ghost.

OK, Ghost here.

We're looking good.

GROUND CONTROL: Roger, Jimmy.

Standing by.

NARRATOR: Just past 4:00
PM, the last heat for the

unlimited class is set to go.

GROUND CONTROL:
Racer number seven,

you are next for the runway.

NARRATOR: With six
planes in the air,

pilots line up
beside a pace plane.

The racers follow that
plane toward the start line.

GROUND CONTROL:
Gentlemen, you look good.

Gentlemen, you have a race.

NARRATOR: Leeward starts
on the outside of the path.

ROBERT "HOOT" GIBSON:
And you're flying

in 100 feet above the ground,
and you're accelerating.

And at the same time,
you've got to be

avoiding the other airplanes.

You've got to be not hitting
the ground, obviously.

You've got to be not
hitting the pylons.

So it's busy.

It's real busy.

Here we go.

NARRATOR: Spectators cheer
on the Galloping Ghost

as it passes pylon six
near the end of lap three.

Looks like the Ghost
is gaining on him!

NARRATOR: Jimmy Leeward is
now in third place in chasing

Voodoo, another P-51.

But at pylon eight,
the Galloping Ghost

suddenly pitches up hard,
then spirals and dives

toward thousands of spectators.

The airplane is
coming straight at me.

The last thing I
saw was the sunlight

shining off the Chrome spinner.

He's coming right at us!

[screams]

NARRATOR: The Galloping
Ghost slams into the ground.

It's the worst disaster in the
history of the Reno Air Races.

[sirens]

64 spectators are injured,
11 people are killed,

including pilot Jimmy Leeward.

ROBERT "HOOT" GIBSON: I knew
right away Jimmy was gone.

I knew there was no
way that he could have

survived something like that.

He had been such a
dear, dear friend.

I just cried.

[music playing]

NARRATOR: Investigators from the
National Transportation Safety

Board, who were already at
the show promoting air safety,

reached the crash
site in minutes.

I'm Clint Crookshanks.

This is Howard
Plangens with the NTSB.

We've been authorized to
take over this investigation.

NARRATOR: They've actually
witnessed the air crash.

Watching the accident
happen was quite unique.

We saw the airplane pitch
up, roll over, hit the crowd.

And the three of us
working were stunned.

NARRATOR: It often takes days
to start an investigation.

But, today, investigators
are at work within minutes.

Nothing can be touched until
we get photographs and nothing

moves, OK?

The airplane hit the ground
at over 500 miles an hour.

And so, there was not much left.

But most of the airplane,
especially the forward part

of the airplane, was
little tiny bits.

NARRATOR: Investigators
divide the grounds into a grid

as they search for evidence
to explain the plane's

sudden loss of control.

Listen up, everybody.

Everything you find goes
into one of these bags, OK?

OK, and then we got
four, five, six, and--

NARRATOR: A searcher
appears with something she

found outside the search grid.

Where did you find this?

Out there?

It was a light piece and it
was far away, further than some

of the other heavier pieces.

OK.

NARRATOR: It landed between
pylons nine and one--

How did it get all
the way over there?

Perfect.

NARRATOR: --1,500 feet
away from the crash site.

We would not have expected
to find it where we did.

[music playing]

NARRATOR: In a hangar near
Sacramento, California,

investigators examined the
accident debris as news reports

broadcast a detailed
photo of the Ghost

just before it crashed.

It shows the left tail trim
tab detaching from the plane.

Where did you find this?

NARRATOR: That's the same piece
found away from the crash site.

Trim tabs are key to
controlling an airplane.

While tail elevators direct an
aircraft to climb or descend,

trim tabs keep the
elevator in place

without the need for
constant adjustment.

If the trim tabs
fail, the aircraft

could go out of control.

Why did you break?

[music playing]

So this is the actual
data from the aircraft

just before it crashed.

NARRATOR: Investigators
examine the Galloping Ghost's

telemetry system,
which is used in place

of a conventional black box.

It collects data on
the plane's performance

and transmits it
to the ground crew.

Speed and RPM look good.

Oil pressure seems fine.

NARRATOR: Almost all data
points show the plane performing

exactly as it should.

But one point stands out.

Wow.

Look at the G load.

G level refers to
the gravitational force

that we experience
here on the Earth.

And all of us
sitting on the ground

here are seeing one G. In the
races, we'd be pulling six Gs.

But Jimmy saw more than that.

He went right off the scale.

Through video
evidence, we were

able to determine that
that G spike was actually

in the neighborhood of 17 Gs.

NARRATOR: 17 Gs is
more than five times

what astronauts
experience on liftoff.

I would have been unconscious.

Someone 30 years old would
have been unconscious.

"Top Gun" would have been
unconscious at the G level

that that airplane experienced.

It's very likely that the G
forces incapacitated the pilot

within a couple of seconds
so that the airplane was then

uncontrolled as
it hit the ground.

[screams]

NARRATOR: There was no
way the pilot could have

steered clear of the crowd.

[music playing]

The spike in G force
raises questions.

Did the left trim tab
fall off, pitching

the aircraft violently upward?

Or did the violent
G force of the climb

tear the plane apart mid-air?

You know, this plane
flew in World War II.

It's almost 70 years old.

And it was highly
modified for speed.

NARRATOR: Investigators
try to uncover

why a modified P-51
Mustang crashed

into a crowd of thousands.

[screams]

They wonder, could years of
modifications to the Galloping

Ghost have turned a sturdy
fighter into an unstable racing

machine?

The original P-51 was
designed to fly long range,

carry extra fuel tanks
underneath the wings,

and fly at, I think,
something like

12,000 pounds gross weight.

Well, we don't need
that for air racing.

So we don't need that much wing.

NARRATOR: In the 60s,
the Galloping Ghost

had its wings shortened
by eight feet and its tail

by one foot, a change
that made the plane

lighter and more streamlined.

The less wing
that you're dragging

through the air at
high speed, the less

drag you're going to have.

Therefore, the faster
you're going to go.

NARRATOR: In 1983,
Leeward bought the plane.

In 1985, he painted it yellow
and raced it over the years

at Reno.

In 2007, he began making
his own modifications

to the Galloping
Ghost, modifications

that took its top speed from
300 to 500 miles per hour.

Did that extra speed affect
the plane's reliability?

Look at this safety report.

The pre-race
service report shows

investigators how the
Galloping Ghost was maintained.

Entries before its final race
provide a startling clue.

They had to
retighten the trim tab

screws on several occasions.

So the airplane was
talking to the crew.

They never
investigated the reason

for the screws coming loose.

NARRATOR: The question now
is, did the left trim tab have

a defect that wasn't noticed?

[music playing]

The team searches the
debris with renewed purpose,

looking for the
hinge that fastened

the tab to the plane's tail.

It looks like a piece
of the trim tab assembly.

NARRATOR: It may be the
investigation's smoking gun.

Half the screw is snapped off.

And what's left is loose.

NARRATOR: A screw that once
fastened the tab to the hinge

is loose, something
that shouldn't happen.

It turns real easy.

NARRATOR: The screw is
supposed to be secured

tightly by a lock nut
fixed to the underside

of the hinge assembly.

The lock nut is
specially designed

to grip the threads of
the screw to ensure it

can't be loosened by vibration.

[music playing]

Analysis of the locknut
leads to a discovery.

The lock nuts on this
particular airplane

had some yellow paint on them.

The airplane was last
painted yellow in 1985.

NARRATOR: It means, the critical
part is at least 26 years old.

The deteriorated nut should
have been replaced long ago.

Microscopic analysis
also reveals

fatigue cracks, the result
of years of vibration.

So vibration finally
broke the screw.

We knew that it had
been loose in order for it

to cause the necessary forces
to fatigue the screw over time.

NARRATOR: Investigators
now believe

they know what caused
the Galloping Ghost's

fatal nosedive into spectators.

[screams]

Aging parts, a loosely
fastened trim tab,

and extreme aerodynamic
forces proved

to be a fatal combination.

11 months after the crash
of the Galloping Ghost

at the Reno Air Races--

Let's go Ghost!

[laughter]

NARRATOR: --the NTSB
announces the probable cause

of the accident.

Traveling at 512 miles per
hour, 200 feet above the Nevada

desert, a loose 26-year-old
locknut causes a weakened screw

in the P-51's left trim tab
to snap, sending the plane

into a violent upward pitch.

The extreme G force
instantly incapacitated

pilot Jimmy Leeward.

I'm sure Jimmy never saw
himself hit the ground.

[screams]

NARRATOR: As a result
of their investigation,

the NTSB issued
safety recommendations

requiring engineering
evaluations

of highly modified aircraft.

It also recommends
improving safety

for spectators and personnel
near the racecourse.

One area that is
consistently dangerous,

and that is taking old planes,
modifying them, and then flying

in the vicinity of
a lot of people who

really are posing a huge risk.

And regular
civilians don't know.

NARRATOR: But sometimes,
that threat from above

comes not from the planes but
from the pilots who fly them.

[music playing]

Mexico's capital, Mexico City,
is a sprawling metropolis

of 20 million people.

[car honks]

Thousands of feet
above it, a Learjet 45

is one of several jets lining
up to land at the city's

busy international airport.

GROUND CONTROL: Victor Mike
Charlie, radar contact,

descend to 200.

200, Mike Charlie.

NARRATOR: Alvaro
Sanchez and Martin Oliva

are at the controls.

Both pilots are captains.

But tonight, It's Oliva
who's flying the plane.

The Mexican government
chartered the Learjet

to carry the interior
minister and his entourage

to Mexico City.

Juan Camilo Mouriño
is just 37 years

old and already a rising star
in the Mexican political scene.

Anybody who becomes
Interior Secretary

has become a very important
figure in Mexican politics.

He was considered
a personal friend

of President Felipe Calderon.

[applause]

GROUND CONTROL:
Victor Mike Charlie,

descend to one 5,000 feet.

Altimeter at 3024.

One 5,000 with
3024, Mike Charlie.

NARRATOR: As the
Learjet approaches

the outskirts of Mexico City,
the pilots prepare to land.

Landing lights.

Yep.

Checked.

NARRATOR: They keep a
close eye on the aircraft

flying ahead of them.

Look.

Yeah.

They're all lined
up in front of us.

Just in time
for the rush hour.

[laughs]

Victor Mike Charlie, reduce
your speed to 180 knots.

Reducing speed to
180, Mike Charlie.

NARRATOR: The air traffic
controller asks the Learjet

crew to slow down to maintain
their distance from the plane

ahead.

It's a busy
international airport.

It's the main airport for Mexico
City, which is a huge city.

So things are
coming at you fast.

ATC telling you to, you
know, turn this heading,

maintain this speed,
slow down to this speed.

There, speed stabilized.

OK.

NARRATOR: This is one of the
busiest and most critical

stages of any flight.

Flap down.

NARRATOR: Sanchez extends
the flap so he can maintain

lift and further reduce speed.

They're about five and 1/2
miles from the airport,

right over the heart of
downtown Mexico City.

Oh my God!

[alarm]

All of a sudden, chaos.

They're flown upside
down and they're

hurtling towards the ground.

[screams]

NARRATOR: Without warning, the
Learjet goes into a steep dive

and plummets toward the ground.

What do we do, Alvaro?

What do we do?

Alvaro!

Give it to me.

Give it to me.

All of a sudden, I saw this
plane flying, like, really low.

I had the time to
turn around and I

started running away from it.

Oh, Alvaro!

No!

Ah!

[screams]

[music playing]

NARRATOR: The crashed
Learjet has devastated Mexico

City's financial district.

[sirens]

All nine people on
board have been killed.

Seven people on the
ground are also dead

and dozens more are injured.

Just remember, like, a lot
of explosions, cars exploding.

[sirens]

NARRATOR: Mexico City
is in chaos as crews

battle to control the fire.

The sudden loss of
the interior minister

leaves the country in shock.

[music playing]

In the aftermath of the tragedy,
Mexico asks for help from

the United States and the NTSB.

As soon as we
heard that there was,

what we would say, the
equivalent of the Mexican vice

president on board, I knew
that it was going to be a very

political investigation
and would require a lot

of politics, a lot of
interpersonal skills,

more than even just the
technical side of things.

Joe Sedor, NTSB.

NARRATOR: Amid the
confusion of the crash,

the investigators'
first job is to identify

the aircraft debris.

All right.

If you're absolutely
sure it's from the plane,

it goes over there, OK?

Everything else I want here.

This plane crashed
into rush hour traffic

in the middle of
one of the world's

biggest, busiest cities.

There's wreckage everywhere.

There's debris.

Is it a car?

Is it a plane?

Well, this is the nose.

Yeah, the whole plane's here.

NARRATOR: An
intensive search turns

up both the cockpit
voice recorder

and the flight data recorder.

They are sent off to Washington
DC, where experts at the NTSB

will try to recover the data.

Meanwhile, the position
of the wreckage

provides a vital clue about
the direction the plane was

flying just before it crashed.

It looks like the
plane was heading

west when they hit the
ground, flying the wrong way.

We knew that he was
coming into Mexico City.

And the first thing
that we noticed

was that the aircraft,
when it struck the ground,

was actually moving
away from the airport.

[music playing]

NARRATOR: Investigators must
answer an obvious question.

[screams]

Why was the Learjet flying
in the wrong direction?

NARRATOR: At the NTSB
lab in Washington DC,

investigators realize the flight
data recorder will be no help

in finding out why
the Learjet carrying

Mexican politician Juan
Camilo Moreño crashed

in the heart of Mexico City.

That's because the recorder
stopped working almost two

years before his final flight.

Investigators now
examine security

camera footage around Mexico
City's financial district.

Yeah, one of these
cameras must have been

looking in the right direction.

NARRATOR: If they're right,
the cameras could have captured

the moments before the crash.

Video is very important
to us, especially

if we don't have any FDR data.

Next?

NARRATOR: They get a break.

Oh, hello, there.

You see the streak of
the aircraft going down.

And we were like, hey,
we got something here.

NARRATOR: The video
reveals that the plane

went into an
extremely steep dive

and then reversed
course in mid-air.

[shouting]

But what exactly caused the
plane to suddenly change

direction is not obvious.

We knew it was coming
in in this direction.

And then, all of a sudden,
then the next thing we know,

it's going in this direction.

How does it get there?

An airplane can't just
automatically turn in flight

and go down.

So we had to determine
what would actually

have to happen in order to get
that airplane in that position.

All right.

I think we waited long enough.

Let's hear it.

NARRATOR: Investigators
finally get a chance to hear

the cockpit voice recorder.

Flap down.

NARRATOR: They
listen to the pilots

descend toward the runway.

Look.

Yeah.

They're all lined
up in front of us.

NARRATOR: There's
nothing unusual until--

The turbulence
from that thing.

Oh, man.

One of the interesting
things that we did here

was that the flight crew
did mention turbulence.

What the hell?

Alvaro!

All right, sounds like that's
where the trouble starts.

Where are we at?

14 seconds before
hitting the ground.

NARRATOR: It sounds
like a Learjet hit

a patch of very unstable air.

Oh my God.

No, Alvaro, no!

Alvaro!

[screams]

We had a normal
flight coming in,

and then we had a loss of
control relatively quick.

So what do you think?

Wake turbulence?

NARRATOR: It's an
intriguing possibility.

Wake turbulence forms when the
low pressure air above the wing

draws high pressure air upward,
creating a swirling vortex,

like a tiny horizontal tornado,
the trails behind the aircraft.

When a smaller plane flies
into these rotating columns

of air at low altitude, they can
spin out of control and crash

into the ground within seconds.

NARRATOR: Investigators learn
that during the approach,

the controller
slotted the Learjet

behind a much larger aircraft.

A Boeing 767 was flying
its approach directly

in front of the Lear 45.

Just in time for rush hour.

[laughs]

NARRATOR: But when radar
data from air traffic control

is analyzed, the surprising
discovery is made.

Separation is
not ideal, but it

shouldn't have been a problem.

NARRATOR: To rule out all
possibility of wake turbulence,

investigators double check
the conditions of the flight.

They discover a critical detail.

The night of the crash,
the 767's wake vortices

would have lingered
dangerously longer than usual.

The reason, exceptionally
calm weather.

In calm conditions, there's no
wind to disperse the turbulence

into harmless air currents.

We had a heavy
aircraft in front,

we had a light aircraft behind.

All the circumstances
came together

to have that trailing Lear 45
have an encounter with the wake

turbulence of the 767.

NARRATOR: The crew could
see the 767 ahead of them.

So he's five miles from us.

NARRATOR: But they mistakenly
thought they were traveling

at a safe distance away.

Like a sledgehammer from
above, the wake turbulence

slammed into the smaller
plane, flipping it over.

It's this powerful
force, but you

don't know that
you're about to hit

it until you're already in it.

NARRATOR: They had flown
into the deadly vortex.

Alvaro!

NARRATOR: This explains the
mid-air change of direction.

The aircraft rolled around
into a sort of a barrel roll.

And then, as it was coming
around, they were pulling out.

And if they would have had
another maybe a thousand feet

or a couple thousand feet,
that they could have actually

recovered the aircraft.

No, Alvaro!

No!

NARRATOR: Investigators now
understand why the jet carrying

Mexico's interior minister
crashed into the streets

of Mexico City.

But something doesn't add up.

They wonder why a crew entrusted
with flying top government

officials didn't use more
caution, especially given

the calm winds that evening.

The 767 is coming
down nice and steady.

Now, look at the Lear.

Should I pull the nozzle?

No, leave it.

Leave it for now.

NARRATOR: In sharp
contrast to the 767,

the Learjet is
descending unevenly,

speeding downward
to lose altitude,

then leveling off to slow down.

If a pilot is really in
control of his airplane,

he can lose altitude and
lose speed at the same time.

If he's not really
in control, he'll

focus on one or the other.

NARRATOR: The
Learjet pilots were

unsuccessful controlling both
their speed and their altitude.

There, speed stabilized.

OK.

NARRATOR: They flew too
fast toward the plane ahead

and dropped down too far--

Flaps down.

NARRATOR: --directly
into the deadly vortex.

If they had maintained the
airspeeds that were requested

to them by air traffic control,
then this approach would

have gone without a hitch.

NARRATOR: Investigators dig
into the work records of the two

Learjet pilots to
understand why they

flew such an erratic approach.

What the hell?

When you look at the
paperwork for both the pilot

and the co-pilot, there
were signatures missing,

there were forms missing.

NARRATOR: When they try
to track down Captain

Oliva's flight instructor--

Let me guess, no
sign of the instructor?

NARRATOR: --they find no
evidence of any training.

Investigators learn that
many of the training

flights Captain Oliva claimed
to have made never happened.

It's a similar story
with Alvaro Sanchez.

The pilots flying a
Mexican government Learjet

had fraudulent credentials.

It's pretty mind
boggling that a pilot

would fake his own credentials.

Your life is at stake too.

You'd think you would want to
have the proper credentials

to fly an airplane.

NARRATOR: It's a
devastating revelation.

Two pilots who couldn't
control their jet

during a demanding descent
in high risk conditions

caused a violent crash in
the heart of Mexico City.

It's highly irresponsible.

It's irresponsible
because, at that point,

you're putting
yourself in danger,

you're putting the people
that you're flying,

you're putting them in danger,
you're violating their trust.

NARRATOR: In the aftermath,
Mexican authorities

suspend the licenses of two
flight schools they suspected

issued false training documents
to the Learjet pilots.

Under no circumstances,
whether we're dealing

with military, civilian,
private, whatever form

of aviation, never
must we ever allow

people to get in an airplane
they're not qualified to fly.

Whether it's a Piper Cub
or whether it's a Boeing

747 or anything in between.

Because we know
where that leads.

Ready when you are, Captain.

NARRATOR: But even
highly skilled

pilots cannot avert
a mid-air tragedy

in the skies over Los Angeles.

NARRATOR: East of Los Angeles,
the suburban city of Cerritos

is waking up.

It's a fast-growing, bustling
community in LA County.

Aeroméxico flight
498's flight path

takes it right over
Cerritos on its way

to Los Angeles
International Airport.

First officer Jose
Valencia is piloting

this leg of the journey.

Ready when you are, Captain.

NARRATOR: Captain Antonio
Valdez Prome navigates.

Down below in the tower, air
traffic controller Walter White

gets his first call from
Aeroméxico flight 498.

Los Angeles approach.

Good morning, this
is Aeroméxico 498.

Aeroméxico 488,
Los Angeles approach.

25 left, final approach course.

Do you have information?

Los Angeles
approach, good morning.

This is Aeroméxico.

NARRATOR: Flight 488
is now officially

inside what's known as the
terminal control area, or TCA.

It's restricted airspace
that's normally found

around heavily congested
airports or hub airports where

the traffic density
is extremely high

and you need to
control the access

into and out of that airspace.

What speed do you want?

We're reducing to 290--

no, no, to 190.

OK, you can hold
what you have, sir.

NARRATOR: As the crew of flight
498 flies over Cerritos--

Seatbelts, airspeed.

NARRATOR: --their DC-9 is
rocked by a violent jolt.

[alarms]

GROUND CONTROL: Aeroméxico 498.

This can't be.

NARRATOR: On the ground,
Cerritos residents

watch in horror as
the DC-9 nosedives

into a quiet neighborhood.

[beeping]

I think I lost one.

Aeroméxico 498, Los
Angeles approach.

[sirens]

[music playing]

FIREFIGHTER (INTERCOM):
[muffled speech]

NARRATOR: Local
emergency crews arrive

on the scene within minutes.

As we approached, I
realized that, in addition

to the aircraft
parts in the street,

there were people, body parts.

As I surveyed the houses and
the crash site around me,

it was a very surreal
experience to stand right there

for probably four
or five minutes

before anybody else
showed up and not

see another living soul.

FIREFIGHTER
(INTERCOM): You've got

wreckage all over the place.

There are no survivors,
just fatalities.

Oh, gosh.

This neighborhood has just been
devastated, just flattened.

NARRATOR: 16 houses
have been damaged,

many completely destroyed.

[music playing]

All the passengers and crew on
Aeroméxico flight 498 are dead

as well as 15 people
on the ground.

As emergency crews grapple
with the horrifying situation,

emergency workers in a
different part of Cerritos

are shocked by another
grisly discovery.

In the playground
of a local school,

they find the wreckage of
a Piper Cherokee Archer

and the bodies of
its three passengers.

The two crashes
must be connected.

But how?

Investigators from the National
Transportation Safety Board

arrive in Cerritos that night.

Proof of a collision between
the two aircraft comes quickly.

There are propeller marks and
paint from the Piper Cherokee

on the tail of the DC-9.

It looks like
the Piper collided

at the tail section of the
DC-9 and the horizontal

stabilizer came off.

And once that happened,
you could no longer

control the pitch of the DC-9.

NARRATOR: The wreckage reveals
that the DC-9 and the Cherokee

collided at a 90 degree angle.

The impact tore off
the airliner's tail

section, causing the nose dive.

The cause of the crash is clear.

But investigators must now.

Solve a deeper mystery
how did the two aircraft

get close enough to collide?

NARRATOR: In the wake of the
Aeroméxico crash in Cerritos

California, investigators
turned to the DC-9's flight

data recorder to
find out why it was

clipped by a Piper Cherokee.

They discover the Aeroméxico
flight was exactly

where it should have been--

Ready when you are, Captain.

NARRATOR: --inside the
terminal control area.

But no one gave the
Cherokee authorization

to fly into the TCA.

The fact of the matter is that
the Cherokee flew into the TCA

and hit the DC-9 in restricted
airspace without a clearance.

NARRATOR: How did the
Cherokee end up in the TCA?

Walter White, the air
traffic controller on duty,

should have been able
to see it on his radar.

Richard Wentworth was
one of the investigators

who interviewed the controller.

At any time, did you see the
Piper Cherokee on your scope?

No.

No, sir.

The Piper's target
was not displayed.

NARRATOR: While the radar
data is being analyzed,

investigators learn that the
Cherokee's pilot, William

Kramer, like most
private pilots,

was navigating by
landmarks, such as freeways.

And that's definitely the 405.

Where is it again?

Perhaps confused by the
tangle of freeways below him,

Kramer may have flown into
the terminal control area

without knowing it.

There are no lines on the
ground that says the TCA starts

here and at this altitude.

NARRATOR: But
investigators still need

to know why the air
traffic controller failed

to keep the two planes apart.

Hey, Carl.

How's it going?

NARRATOR: They here from
controllers from Los Angeles

International Airport,
who've described

problems with their equipment.

We had reported
problems with the radar

not picking up
targets several times.

NARRATOR: It's a
terrifying theory.

Was the disaster in Cerritos
caused by failing technology?

Investigators pour
over radar data

from Los Angeles International
Airport traffic control,

hoping to answer that question.

When radar signals
strike a target,

they bounce back
to the receiver.

But if buildings or mountains
interrupt the radar,

the return signal can disappear.

We reviewed that data.

We had no evidence that
there were any malfunctions

of any systems in Los Angeles.

NARRATOR: But investigators
do discover the controller

was simultaneously handling
another small plane, a Grumman

Tiger.

There was an aircraft that
was east of the airport,

which he became involved in.

OK, you are right in the
middle of the TCA, sir.

Roman 66, Romeo, I
suggest in future,

you look at your TCA chart.

The problem with
the conversation

between the controller and
the pilot of the Grumman

is that it went on too long.

Why were you so
mesmerized by the Grumman?

I thought he posed a risk.

This occurred
during a critical time

at which the Aeroméxico and
the Cherokee were merging.

NARRATOR: Investigators believe
that the controller's divided

attention, perhaps made worse
by the limitations of an older

radar system, is the reason
why he didn't warn the DC-9

about the approaching Cherokee.

And see if you can find
any landmarks that we might

be able to use as a visual.

NARRATOR: They suspect that the
Cherokee's pilot was searching

for landmarks on the ground--

I just wanted a visual
landmark that I can see.

NARRATOR: --while the
DC-9 was approaching

from the other direction.

In addition, NTSB
investigators also

believe the DC-9's
busy flight crew

may have missed
spotting the Cherokee

because of its small size.

It's possible that
during part of the approach

the aircraft was actually
behind the center post.

And unless the pilot moved
his head back and forth

to clear that airspace,
it's possible the aircraft

was obscured.

[music playing]

NARRATOR: The NTSB
report reveals

several tragic weaknesses in
the air traffic control system.

Chief among them, pilots
cannot be relied upon

to see and avoid each other.

It recommends improvements that
are still in place to this day.

[music playing]

The Federal Aviation
Administration,

which regulates the United
States airline industry,

reacted swiftly.

A new system for
radar facilities,

called Mode C
Intruder, is designed

to aid air traffic controllers.

If an aircraft should
inadvertently intrude,

the controller will now be given
a visual and an aural alert,

thus giving him time to provide
a timely warning to the pilot.

NARRATOR: In addition,
an early warning system

for pilots called, Traffic
Collision and Avoidance,

or TCAS, is also developed.

TCAS alerts pilots
almost a minute

before a potential collision,
instructing them to climb

or descend to avoid the
approaching aircraft.

Within a year, the old radars
at Los Angeles International

Airport were replaced.

Whenever you've got an
airplane falling out of the sky

and hitting a
civilian community,

that is doubly frightening.

It's one thing to just
being reactive to a crash.

It's another thing
when the crash has

just rained death from the air.