All language subtitles for Air.Disasters.S11E05.Lethal.Turn.1080p.PMTP.WEB-DL.AAC2.0.H.264-maldini_track3_[eng]

CAPT. WIYOGO: Come
on, climb! Climb! Climb!

NARRATOR: An Airbus A300
veers fatally off course.

CAPT. WIYOGO: No! No! Nooooo!

[Crash]

SANTOSO:
It was the biggest human
loss in Indonesian history.

ROBERT: It really
was overwhelming.

SANTOSO: These are two
pieces we need to find.

SANTOSO: The task was
to find the black box.

NARRATOR: As investigators begin
to examine the evidence...

AIR TRAFFIC CONTROLLER:
Indonesia 152, turn
right heading zero-four-six.

SANTOSO: Here, right on course.

NARRATOR: ... each new clue is
more perplexing than the last.

ROBERT: That's go-around power.

SANTOSO: We
cannot figure it out.

ROBERT: The impact
point was nowhere near

where we would
expect the aircraft to be.

ROBERT: Where did they
think they were going?

We just didn't understand that.

[♪ theme music ]

♪

NARRATOR: There are
222 passengers on board

Garuda Indonesia Flight 152.

They're on their way
to the city of Medan

on the Indonesian
island of Sumatra.

CAPT. WIYOGO: Let's stay on
autopilot as long as we can.

FO. ZUWALDI: Yes, sir.

NARRATOR: Captain Rachmo Wiyogo
has been flying in Indonesia

for nearly twenty years.

He's very familiar
with today's flight path.

CAPT. WIYOGO: For missed
approach, climb straight ahead

to 2,500 and contact ATC.

You don't have to
write this down. Just relax.

FO. ZUWALDI: Yes. Okay, sir.

NARRATOR: Tahta Zuwaldi
has only recently upgraded

from flight
engineer to first officer.

The plane they're
flying is an Airbus A300,

one of the most reliable
commercial airliners in the sky.

Flight 152 left the
Indonesian capital of Jakarta

nearly ninety minutes ago.

Headed northwest, it is expected
to arrive at its destination

in about half an hour.

ATIS: Surface winds
calm. Visibility 400 meters.

NARRATOR: An automatic
weather report alerts the crew

to one factor about their
flight that's not routine.

ATIS: Present weather: smoke.

NARRATOR: Forest
fires in Sumatra have sent

a thick blanket of smoke
across all of Southeast Asia.

It's wreaking havoc on people's
health and on air traffic.

DAVID: Smoke is
limiting visibility to a degree

that would make the
descent and the approach

really quite
difficult -- not impossible,

but really quite difficult.

NARRATOR: The cabin crew of
Flight 152 begins preparing

for the upcoming descent.

On the ground,
it's a busy afternoon

for Medan air
traffic controllers.

FO. ZUWALDI: Indonesia 152
requesting descent clearance.

NARRATOR:
They're handling flights from
several domestic airlines,

including Merpati,
Bouraq and Garuda Indonesia.

AIR TRAFFIC CONTROLLER:
Confirming descent to
flight level one-four-zero.

NARRATOR: The controller clears
Garuda 152 to begin its descent.

FO. ZUWALDI: Descending to
flight level one-four-zero,

Indonesia 152.

NARRATOR: Medan
Airport has just one runway.

Right now, the controller
has a Bouraq Airlines flight

ready to take off.

He needs to slow the
approaching Garuda flight

until that plane
clears the runway.

AIR TRAFFIC CONTROLLER:
Indonesia 152, descend
to 3,000 feet

for runway zero-five.
Reduce speed two-two-zero.

FO. ZUWALDI:
Reduce speed to two-two-
zero knots, Indonesia 152.

Seat belt, no smoking.

NARRATOR: Less than fifteen
minutes from the airport,

Flight 152 descends
through 10,000 feet.

CAPT. WIYOGO: It's smoky
here below 10,000.

FO. ZUWALDI: Oh yeah.

DAVID: The pilot would
never have been able to get

any external visual cues.

He would have been
flying entirely on instruments.

♪

NARRATOR: The reduced
visibility puts added pressure

on the controllers.

DAVID: If there is smoke
all the way down to the ground,

the controller knows the pilot
is going to encounter problems.

They're gonna need all
the help they can get,

and the controlling
should be very accurate.

NARRATOR: The captain adjusts
the power to his engines.

AIR TRAFFIC CONTROLLER:
Merpati 152, turn left

heading two-four-zero to
intercept runway zero-five.

CAPT. WIYOGO: Number one
always lags behind a bit,

so keep an eye on it for me.
FO. ZUWALDI: Okay.

AIR TRAFFIC CONTROLLER:
Indonesia 152, do you read?

FO. ZUWALDI:
Indonesia 152. Say again?

AIR TRAFFIC CONTROLLER: Okay.
Turn left heading two-four-zero,

two-three-five now to
intercept runway zero-five.

FO. ZUWALDI: Roger, left heading
two-three-five, Indonesia 152.

NARRATOR:
The plane below has now
taken off. The runway is clear.

AIR TRAFFIC CONTROLLER:
Bouraq 683, turn left
heading one-two-zero.

Indonesia 152, traffic clear.
Descend to 2,000 feet.

FO. ZUWALDI: Descending to
2,000 feet, Indonesia 152.

NARRATOR: If it
weren't for the heavy smoke,

passengers would be able
to see the ground by now.

DAVID: They had
very limited visibility.

Anybody who's
driven a car in fog

will know what
I'm talking about.

AIR TRAFFIC CONTROLLER:
Indonesia 152, turn
right heading zero-four-six.

FO. ZUWALDI: Turn right heading
zero-four-six, Indonesia 152.

CAPT. WIYOGO: Flaps 8.

FO. ZUWALDI:
Speed check. Flaps 8.

CAPT. WIYOGO:
The cockpit is hot. See
what you can do. It's so hot.

FO. ZUWALDI: It's set to
cool, sir. It should be fine.

NARRATOR: Any second
now, the controller expects

to see Flight 152
turn onto final approach.

♪

CAPT. WIYOGO: What?

NARRATOR: The
Airbus has somehow become

dangerously close to the ground.

CAPT. WIYOGO: Come
on, climb! Climb! Climb!

NARRATOR: The crew struggles
to raise the plane's nose

and gain altitude.

But the 130-ton jet
takes time to respond,

time they don't have.

[Chaos]

CAPT. WIYOGO: No!

[Screaming]

No! No! Noooo! Noooooo!

[Crash]

♪

NARRATOR: Locals
rush to the crash site,

seventeen miles
from Medan airport.

It's soon clear there's
nothing they can do to help.

All 234 people
onboard the flight are dead.

This is the deadliest aviation
accident in Indonesia's history.

The entire nation wants answers.

MARDJONO:
We should come to the answer
on not only what happened,

how it happened but
also why it happened.

NARRATOR: Investigators
soon join the throngs

of police and locals
already at the crash site.

SANTOSO: Let's see how
far back this wreckage goes.

NARRATOR:
Santoso Sayogo is a key member
of the investigative team,

and the accident has
affected him personally.

SANTOSO: I knew both the
captain and first officer

for a long, long time.

When you found out
that your two friends

was the victim of the accident,

it's quite a
shocking experience.

ROBERT: Santoso! We'll need
to secure the site somehow.

NARRATOR: The Air
Accidents Investigation Branch

sends Rob Carter to
assist with the investigation.

ROBERT:
The site was chaotic. There
were lots of people around,

some in uniform but it
didn't seem like very many.

There was no overall control.

Lots of people doing
different things, very little

that seemed to be related
to accident investigation.

The smell was almost
overpowering at that stage,

coupled with the heat and
the humidity and the pollution.

It really was overwhelming.

NARRATOR: The chaotic scene is
an immediate concern for Carter.

He's worried the
lack of security

could compromise
the investigation.

ROBERT: A tremendous
number of local people

were going over the
wreckage in different ways

and they were
carrying pieces away.

We worried that they might be
carrying away bits of aircraft,

which we'd be
really interested in.

NARRATOR: If authorities
can't gain control of the site

and protect valuable evidence,
the truth about what happened

to Garuda Indonesia
Flight 152 may never be known.

♪

SANTOSO: Okay, good.

The left engine was found here.

ROBERT: Excellent.

NARRATOR: The
wreckage from Flight 152 lies

seventeen miles
southwest of Medan airport.

The compact nature of the
crash zone tells investigators

that the plane was in one
piece when it hit the ground.

ROBERT: It looked as if
we had most of, if not all,

of the aircraft
within an area 120 by 80.

That's pretty compact.

NARRATOR:
The wreckage tells investigators
something else as well --

something they can't explain.

The debris field shows
that the plane was flying

away from the airport when
it slammed into a hillside

southwest of the runway.

It's exactly
opposite from the direction

they should have been flying.

ROBERT: One of the things
that seemed so strange was

where the impact point was.

It was nowhere near where we
would expect the aircraft to be

for the proper sort of
approach into the airport.

We just didn't understand that.

SANTOSO: These are two
pieces we need to find.

NARRATOR: They hope the
plane's flight recorders

can help clear up the mystery.

SANTOSO: They should be in
this area here. Okay, let's go.

MARDJONO: Our principle
is find the black box,

and the clues and
the evidence are there.

NARRATOR: Investigators
fear the boxes may have been

carried off by looters.

They recruit hundreds of local
people to search for them.

ROBERT: We were really
looking very strongly for

the cockpit voice
recorder, flight data recorder

really to fill in any sort of
detail on how this had happened.

NARRATOR: At the same
time, they gather information

from the air traffic controller,

the last person to have
communicated with Flight 152.

AIR TRAFFIC CONTROLLER: They
approached from the southeast.

I was trying to
bring them in this way,

a left turn and a right turn

that gets them
into runway zero-five.

NARRATOR: The
controller suspects the captain

somehow
misinterpreted his instructions

and missed the final turn.

AIR TRAFFIC CONTROLLER:
He didn't understand
which way to turn.

He made a left
turn here instead.

But without the cockpit
recording and the flight data,

it's impossible to say why
the plane turned the wrong way.

Perhaps there was
a mechanical failure

or some other
last minute crisis.

SOERJANTO: We could not
determine why the captain

make the aircraft
turning to the left.

This is a very interesting.
This is... it's a big puzzle.

NARRATOR: With no sign of
the black boxes, investigators

gather air traffic
recordings made in the tower.

It's hoped they can shed some
light on why the plane turned

away from the airport
instead of towards it.

ROBERT: We were still
wondering whether it could be

some sort of systems
failure, possibly even

some sort of mild
structural failure,

some distracting
aspect for the pilots.

It really left
that pretty wide open.

SANTOSO: Roll tape.

AIR TRAFFIC CONTROLLER:
Confirming descent to
flight level one-four-zero.

NARRATOR: The air
traffic recordings capture

only the radio calls between
the pilots and the controller.

AIR TRAFFIC CONTROLLER:
Indonesia 152, descend
to 3,000 feet

for runway zero-five.

NARRATOR: They're not as helpful
as a CVR recording, which

would reveal all sounds and
conversation inside the cockpit.

AIR TRAFFIC CONTROLLER:
Reduce speed to two-two-zero.

SANTOSO: He needs to
get Bouraq 683 airborne.

NARRATOR: But investigators
listen closely for any clue

as to why the A300
veered so badly off course.

At first, the communication
seems completely normal.

AIR TRAFFIC CONTROLLER:
Merpati 152, turn left heading

two-four-zero to
intercept runway zero-five

from the right side.

NARRATOR:
But then, the controller
uses the wrong call sign.

SANTOSO: You have Merpati 152,
and now he's got Garuda 152.

NARRATOR: Records show
that earlier in the day,

the controller was
talking to a Merpati flight

with the same
number, one five two.

It seems that now he's
mixed up the two call signs.

DAVID: Instead of Garuda
152, he said Merpati 152.

The Garuda pilot
didn't pick this message up

for obvious reasons.

AIR TRAFFIC CONTROLLER:
Indonesia 152, do you read?

FO. ZUWALDI:
Indonesia 152. Say again?

DAVID: Then suddenly
the controller realized

that he'd given
the wrong call sign,

so he called up
for a second time.

AIR TRAFFIC CONTROLLER:
Okay. Turn left heading

two-four-zero...
two-three-five now

to intercept runway zero-five.

SANTOSO: Left
heading two-three-five.

FO. ZUWALDI: Roger, left heading
two-three-five, Indonesia 152.

NARRATOR:
It appears the misunderstanding
is quickly cleared up.

SANTOSO: The controller
says they made that turn.

NARRATOR: After the
brief moment of confusion,

the Garuda flight is
exactly where it should be.

FO. ZUWALDI: On heading
two-one-five, Indonesia 152.

SANTOSO: That puts them
about here, right on course.

One more right turn and
he's lined up with the runway.

AIR TRAFFIC CONTROLLER:
Indonesia 152, turn
right heading zero-four-six.

SANTOSO: There it is.
Clear as day.

FO. ZUWALDI: Turn right heading
zero-four-six, Indonesia 152.

SANTOSO: Okay, stop there.

They definitely
understood turn right.

NARRATOR: How the
flight went so horribly wrong

in the final few
moments is baffling.

SANTOSO:
It's in the exact opposite
direction they were told.

Why?

SANTOSO: The ATC
give instruction,

"Indonesia 152 turn right
onto heading zero-four-six."

But the aircraft
turned to the left.

At that stage we do
not have any clue at all.

NARRATOR: Investigators need the
CVR if they hope to figure out

what exactly went on in
the cockpit of Flight 152.

♪

A week after the crash of
Garuda Indonesia Flight 152,

devastating scenes
of loss and suffering

underscore the
accident's human toll.

Indonesians from
all walks of life

want to know what
caused this deadly tragedy.

♪

SANTOSO: They
have to be somewhere.

Let's go back to where
we started and look again.

Let's go. Come on. Let's go.

NARRATOR: There's still no sign
of the plane's black boxes.

Investigators are
beginning to worry that

the answers so many people are
hoping for may never be found.

ROBERT: We've got to find them.

ROBERT: It was very
frustrating not having

the cockpit voice recorder
and the flight data recorder.

They are really crucial to
understanding the subtleties

of an aircraft accident.

♪

NARRATOR:
The terrible conditions at the
accident site aren't helping.

MARDJONO: At that
time, it was rainy season,

and you can imagine how wet
it was and slippery as well.

NARRATOR: Despite the
setbacks, the team presses on.

ROBERT:
Let's see if we can figure
out what this plane was doing.

NARRATOR: They collect
key pieces of wreckage,

including flight
instruments from the cockpit.

Soerjanto Tjahjono of the

National
Transportation Safety Committee

hopes those
instruments will tell him

how the plane was performing.

SOERJANTO: We could
not find the black boxes,

so we used anything from
the cockpit like the gauges,

any instrument in the cockpit.

NARRATOR: Many of the gauges
on this version of the Airbus

are electronic, which means
that when they lose power they

display their final readings
like a snapshot in time.

ROBERT:
When electrical power goes
off, the instrument freezes.

NARRATOR: Those readings
provide valuable insight

into the final
moments of Flight 152.

ROBERT: There it is. It looks
like one-point-five-five-two.

That's go-around power.

They were trying to
fly out of trouble.

ROBERT: The engine instruments
showed us that the engines

were actually at a
very high level of thrust

at the point that they
lost electrical power.

NARRATOR: The finding
reveals that the pilots

saw the danger ahead
and tried desperately

to get their plane to climb.

ROBERT: The crew had responded
by increasing the engine thrust

when they realized they
were close to the ground.

NARRATOR: As the
evidence begins to add up,

the likelihood of a mechanical
failure aboard Garuda 152

looks increasingly remote.

ROBERT: It sure seems like
the aircraft was under control.

ROBERT: Putting it all together,
the instruments seemed

to indicate to us that
the aircraft was what we call

"a going concern"
when it hit that ridge,

that it was some sort of
controlled flight into terrain.

DAVID: Controlled means
that there's nothing wrong

with the airplane.

[Crash]

And yet it plows
into a mountainside.

♪

NARRATOR:
It's been twenty-six days
since the crash of Flight 152.

Investigators still have no
explanation for its mysterious

final turns and fatal impact.

But then they get
their first big break.

SANTOSO: Well, well, well.

NARRATOR: It turns
out that the plane's

voice and data recorders were
not carried off by looters,

but they were almost
completely hidden from sight

in the dense Indonesian forest.

SANTOSO: It was a
surprise for us to find that

the two black box were
sitting there for 26 days

until we found it in
very soft soil and entangled

with the root of
the falling tree.

SANTOSO: Let's hope
they hold some answers.

NARRATOR: They rush the boxes
to a lab where technicians

will work to recover
cockpit sounds and conversation

along with detailed
aircraft performance data.

The long wait for the most
crucial evidence is almost over.

SANTOSO: We tried to
concentrate first on the FDR

and try to figure out the
flight path of the aircraft.

NARRATOR: When investigators
plot the newly found data,

they see that it
finally rules out any chance

of a mechanical failure.

ROBERT: So left
away from the airport

and then a right turn
smack into the mountains.

NARRATOR: It clearly
shows that the pilots

deliberately
commanded that fatal turn.

ROBERT: Where did they
think they were going?

Can you bring me the
descent profile, please?

SANTOSO: After we got the FDR,
some questions got some answers.

NARRATOR: The data also
shows that the plane was

in a steady descent
until it hit a treetop...

at about 1,500 feet.

ROBERT: So why didn't
they level off at 2,000 feet?

AIR TRAFFIC CONTROLLER:
Indonesia 152, traffic clear.

Descend to 2,000 feet.

NARRATOR: The crew was
not cleared to descend

any lower than 2,000 feet. They
should have held that altitude.

♪

ROBERT: So here we were
somehow with the aircraft

hitting a tree about 500 feet
below its last cleared altitude.

[Crash]

That was a real mystery.

NARRATOR: Investigators
now know the pilots turned

in a direction opposite to
the controller's instructions

and dropped below
their assigned altitude.

What they still
don't know is why.

They hope the cockpit voice
recorder can provide an answer.

SANTOSO: Let's start
with turn number one... here.

♪

FO. ZUWALDI: Indonesia 152
requesting descent clearance.

NARRATOR: For Santoso
Sayogo, the job of listening

to the recording
comes with an extra burden.

SANTOSO: I knew both pilots, the
captain and the first officer,

and I personally can
recognize whose voice

are coming from the CVR.

It's not easy
listening to the tape.

AIR TRAFFIC CONTROLLER:
Merpati 152, turn left
heading two-four-zero

to intercept runway
zero-five from the right side.

SANTOSO: Okay, that's
the confused call sign.

CAPT. WIYOGO: Number one
always lags behind a bit,

so keep an eye on it for me.

FO. ZUWALDI: Okay.

NARRATOR: The tape
reveals that the Garuda pilots

don't respond to
the first instruction

because they don't
think it's for them.

AIR TRAFFIC CONTROLLER:
Indonesia 152, do you read?

FO. ZUWALDI:
Indonesia 152. Say again?

AIR TRAFFIC CONTROLLER:
Okay. Turn left
heading two-four-zero...

two-three-five now to
intercept runway zero-five.

NARRATOR: The
controller repeats himself.

FO. ZUWALDI: Roger, left heading
two-three-five, Indonesia 152.

NARRATOR: The crew then
makes the turn as instructed.

CAPT. WIYOGO: Why so far out?
SANTOSO: So far out?

NARRATOR: And yet the
recording leaves investigators

with a disturbing impression.

FO. ZUWALDI: 152,
heading two-three-five.

Confirm that we are
clear of the mountainous area.

SANTOSO: He doesn't
sound sure of where he is.

ROBERT: There seemed to
be some degree of confusion

between the pilots and
the air traffic controller

as to where the aircraft was.

AIR TRAFFIC CONTROLLER:
Confirm, sir. Continue turning
left heading two-one-five.

SANTOSO:
They're on course. A right
turn toward the runway is next.

AIR TRAFFIC CONTROLLER:
Indonesia 152, turn
right heading zero-four-six.

FO. ZUWALDI: Turn right heading
zero-four-six, Indonesia 152.

SANTOSO: They
turned left instead.

NARRATOR: What
investigators hear next

makes the left turn
even more baffling.

CAPT. WIYOGO: Flaps 8.

FO. ZUWALDI:
Speed check. Flaps 8.

NARRATOR:
Even though the crew is
turning away from the airport,

they're configuring their plane
as though heading towards it.

SANTOSO:
Why would you extend flaps while
turning away from the airport?

What if he thinks he is
turning towards the airport?

What if he thinks he's here?

He believes he has to turn
left to get to the runway.

NARRATOR: Feeling he may
be close to a breakthrough,

Santoso Sayogo reviews
the airport approach chart.

DAVID: The charts lay out
what the normal approach is,

and the pilots
normally expect to fly that.

NARRATOR:
He discovers that Garuda 152
wasn't on the standard approach.

The standard approach to Medan
is from the left side, which

involves making a final left
turn to line up with the runway.

But because there was
an aircraft departing,

the Garuda captain was
instructed to approach

from the right
side of the runway,

requiring something
he wasn't used to --

a right turn before landing.

DAVID: The controller
took them in a direction

which was not what
they would have expected

according to the
approach charts.

But there shouldn't really
have been a problem with that.

Controllers are supposed
to confirm the approach path

with the pilots well
before they get to the runway.

SANTOSO:
How could he not have known
which approach he was flying?

Back to 1:27, please.

[Tape rewinding]

AIR TRAFFIC CONTROLLER:
Merpati 152, turn left

heading two-four-zero to
intercept runway zero-five

from the right side.

NARRATOR: As Santoso
Sayogo listens again

to what he thought was a
harmless call sign mix-up,

he suddenly realizes that
it had major consequences.

FO. ZUWALDI:
Indonesia 152, say again.

NARRATOR: When the
controller repeats

the approach instructions, he
leaves out a critical detail.

AIR TRAFFIC CONTROLLER: Turn
left heading two-four-zero...

two-three-five now to
intercept runway zero-five.

SANTOSO: He didn't repeat which
side they were approaching from.

DAVID: He should
have made it clear:

You're not going to come in

from the left-hand
side of the runway.

You're going to come in
from the right-hand side.

SANTOSO: He thinks
he's flown past the airport

when he's told
to make this turn.

He's expecting the
next turn to be a left turn

but instead he's
told to turn right.

NARRATOR: It
seems that the captain,

still unable to see the
ground through the smoke,

dials in a left
turn out of habit.

It is a tragic error
that leads to disaster.

But investigators now wonder,
why did the first officer

not notice his
captain's mistake?

AIR TRAFFIC CONTROLLER:
Indonesia 152, turn
right heading zero-four-six.

FO. ZUWALDI: Turn right heading
zero-four-six, Indonesia 152.

NARRATOR: First Officer
Zuwaldi clearly acknowledges

the instruction
for a right turn.

Yet seconds later,
the plane turns left.

It's almost
impossible to understand.

Investigators
have established that

the captain of Garuda Indonesia
Flight 152 made a fatal turn

after a radio call
mix-up left him with

a confused mental picture
of the approach he was flying.

DAVID: The vectors,
the directions given them

by the air traffic controller,
can create a bit of confusion.

Controllers didn't make it
clear enough to the pilots

that this was not going
to be the standard pattern.

AIR TRAFFIC CONTROLLER:
Indonesia 152, turn
right heading zero-four-six.

FO. ZUWALDI: Turn right heading
zero-four-six, Indonesia 152.

NARRATOR: They focus on
the words of the first officer

in an attempt to
understand why he didn't

immediately react
to the wrong turn.

CAPT. WIYOGO: It's getting hot,
isn't it? The cockpit is hot.

See what you can
do. It's so hot!

SANTOSO: The captain
asked the first officer

to check the air conditioning.

DAVID: The co-pilot turned
his eyes upward to the panel

where he checked the
air conditioning controls.

NARRATOR: The brief
distraction diverts

the first officer's
attention from his instruments

at a critical moment.

FO. ZUWALDI: It's set to cool,
sir. It should be fine.

DAVID: As a result, the co-pilot
missed crucial information

from the instruments.

FO. ZUWALDI: Turn right!

SANTOSO: He looked back.

He was surprised to find the
aircraft turning to the left

instead of turning to the right.

CAPT. WIYOGO: Indonesia 152,
confirm turning left or right

heading zero-four-six.

AIR TRAFFIC CONTROLLER:
Turning right, sir.

FO. ZUWALDI:
Sorry, captain. Sorry.

CAPT. WIYOGO: Roger, 152.

AIR TRAFFIC CONTROLLER:
152, confirm you
are turning left now.

CAPT. WIYOGO: We
are turning right now.

AIR TRAFFIC CONTROLLER: 152,
okay. Continue turning left.

NARRATOR: In all the confusion
over which way to turn...

CAPT. WIYOGO: Turn left?
We are turning right now.

AIR TRAFFIC CONTROLLER:
Oh God! Okay.

NARRATOR: ...
valuable seconds are lost.

SANTOSO: They're flying
straight towards the mountain.

ROBERT: There were many
confusing factors for him.

CAPT. WIYOGO: What?

ROBERT: The smoke pollution
was certainly one of them.

The confused instructions
of air traffic control.

He did not really
have a good mental picture

of where the aircraft was
and where it was meant to be.

CAPT. WIYOGO:
Climb! Climb! Climb!

SANTOSO:
The moment they took the
wrong turn, they were doomed.

DAVID: It was this
uncertainty, lack of clarity

in the captain's head which
really let this accident happen.

NARRATOR: The recording helps
explain how Garuda Flight 152

ended up so badly off course.

But it doesn't answer
another critical question.

AIR TRAFFIC CONTROLLER:
Indonesia 152, traffic
clear. Descend to 2,000 feet.

FO. ZUWALDI: Descending to
2,000 feet, Indonesia 152.

NARRATOR: The crew was
instructed to descend no lower

than 2,000 feet,
and their autopilot

should have kept
them at that altitude.

DAVID: They had gone
straight through 2,000 feet

and were heading for
1,500, and that was too low.

SANTOSO: How did they
end up below 2,000 feet?

ROBERT: Either the autopilot had
failed in some way or other,

which is unusual, or the crew
had input the wrong altitude.

NARRATOR: Unfortunately
for investigators,

the plane's autopilot system
was destroyed in the crash.

DAVID: This impact was so severe

they could pick up
the bits afterwards,

but they couldn't
establish whether there was

something wrong
with it on the day.

NARRATOR: Maintenance
records show no history

of the autopilot ever failing
to maintain proper altitude,

so a malfunction seems unlikely.

And a report from
Airbus all but eliminates

the possibility of
autopilot failure.

Engineers calculated that
the odds of such a failure

are less than
one in two billion.

ROBERT: It's almost
impossible for it to fail.

FO. ZUWALDI: Descending
to 2,000 feet, Indonesia 152.

NARRATOR: Investigators suspect
the captain made an error

while entering
his minimum altitude.

ROBERT: It was more
probably crew missetting

than it was autopilot failure.

CAPT. WIYOGO: Indonesia 152,
confirm turning left or right

heading zero-four-six.

AIR TRAFFIC CONTROLLER:
Turning right, sir.

FO. ZUWALDI:
Sorry, captain. Sorry.

CAPT. WIYOGO: Roger, 152.

NARRATOR: As the aircraft passes
below its target altitude

of 2,000 feet...

AIR TRAFFIC CONTROLLER:
152, confirm you are
turning left now.

CAPT. WIYOGO: We
are turning right now.

NARRATOR: ... the
pilots are engaged in

a confusing conversation
about which direction to turn.

AIR TRAFFIC CONTROLLER: 152,
okay. Continue turning left.

CAPT. WIYOGO: Turn left?
We're turning right now.

ROBERT: They were so
preoccupied with their turn

they didn't
notice their altitude.

SANTOSO: Both
pilots didn't realize that

the aircraft
already left 2,000 feet.

NARRATOR: By the time the
first officer does notice

the dangerously low altitude...

FO. ZUWALDI: We're descending.
CAPT. WIYOGO: What?

NARRATOR: ... it's too late.

DAVID: The quality of their
monitoring of their instruments

was not up to scratch.

CAPT. WIYOGO: Come
on, climb! Climb! Climb!

DAVID: And that's
why they got too low

and they hit the high ground.

♪

[Crash]

NARRATOR: It's finally clear
how Garuda Indonesia Flight 152

dropped below the
minimum safe altitude.

But there are still
important questions to answer.

AIR TRAFFIC CONTROLLER:
Indonesia 152, traffic
clear. Descend to 2,000 feet.

NARRATOR: The controller
in Medan had a read-out

of Flight 152's
altitude and direction.

If he had recognized the
danger and warned the crew,

hundreds of lives
could have been saved.

Why didn't that happen?

FO. ZUWALDI: Descending to
2,000 feet, Indonesia 152.

NARRATOR: Investigators
need to understand

why the Medan controller
never warned the Garuda pilots

of impending danger.

They pour over the
technical specifications

from Medan's radar system.

Most advanced radar systems
refresh every five seconds.

But they soon discover
that the radar in Medan

is far from advanced.

ROBERT: The radar only
refreshed every twelve seconds.

♪

DAVID: That means the controller
only gets an updated picture

of where the airplane
is every twelve seconds.

AIR TRAFFIC CONTROLLER:
152, confirm you are
turning left now.

CAPT. WIYOGO: We
are turning right now.

DAVID: A lot can
happen in twelve seconds.

So when the pilot turned

in completely the
wrong direction...

AIR TRAFFIC CONTROLLER:
Continue turning left.

DAVID: ... the
controller was not seeing

what the pilot was doing...

AIR TRAFFIC CONTROLLER: Oh God.

DAVID: ...until it was
getting to be too late.

♪

[Crash]

♪

NARRATOR: Investigators are
close to fully understanding

the tragic crash of Flight 152.

There's just one
last mystery to solve.

Most commercial jets
have a cockpit alarm

that sounds when the plane
flies too close to terrain.

GPWS: Terrain.
Terrain. Pull up. Pull up.

NARRATOR: It's called the Ground
Proximity Warning System,

a loud automated voice
alerting pilots to danger.

ROBERT: One of the
big questions for us was:

Why did the accident
happen when the aircraft

was equipped with a Ground
Proximity Warning System?

NARRATOR: According to
the flight data recorder,

the GPWS on Flight 152
was triggered five times.

The crew should have
heard the first warning

thirty-seven
seconds before impact.

But when they check
the cockpit recording,

they only hear
the voice alarm once.

FO. ZUWALDI: Pull
up. Pull up. Pull up.

NARRATOR: And it comes just
four seconds before impact.

Something's not right.

They send the
tape to an audio lab

where sound technicians enhance
the quality of the recording.

♪

Listening to the enhanced tape,

investigators make
a stunning discovery.

♪

FO. ZUWALDI: Pull
up. Pull up. Pull up.

NARRATOR: The
alert "Pull up, pull up"

is not the sound of
an automated voice.

SANTOSO: It's definitely
Zuwaldi, the first officer.

SANTOSO: Then we realized the
recorded of "Pull up, pull up"

wasn't from the GPWS, but
it was from one of my friends.

NARRATOR: It can
mean only one thing.

SOERJANTO: We knew that
the GPWS was not working.

NARRATOR: It's ultimately
revealed that there is a flaw

in the GPWS that prevents
a warning from sounding

when planes are descending

over certain types
of mountainous terrain.

SANTOSO: The GPWS never
give the warning to the pilot.

ROBERT: Over the years,
GPWS has saved countless lives.

It was sad in this case
that those lives weren't saved,

and the modern
systems, enhanced GPWS

certainly would
have worked way better.

NARRATOR: Investigators
have finally uncovered

the tragic series of events that
led to the loss of 234 lives.

It all starts with a controller

who confuses one
call sign for another.

AIR TRAFFIC CONTROLLER:
Merpati 152, turn left
heading two-four-zero

to intercept runway zero.

CAPT. WIYOGO: Number one
always lags behind a bit,

so keep an eye on it for me.

NARRATOR: The mix-up
means the crew of Flight 152

never hear a critical
instruction to approach the

runway from the right side
instead of the usual left.

FO. ZUWALDI:
Indonesia 152, say again.

NARRATOR: The captain
compounds the problem

when he enters an incorrect
altitude into the autopilot.

AIR TRAFFIC CONTROLLER:
Indonesia 152, traffic
clear. Descend to 2,000 feet.

FO. ZUWALDI: Descending to
2,000 feet, Indonesia 152.

NARRATOR: The error keeps the
autopilot from holding the plane

at 2,000 feet as
the crew expects.

♪

Thick smoke from forest
fires obscures the view

of landmarks on the ground.

Thinking the
runway is to his left,

the captain turns away from
the airport towards mountains.

AIR TRAFFIC CONTROLLER:
152, confirm you are
turning left now.

CAPT. WIYOGO: We
are turning right now.

AIR TRAFFIC CONTROLLER: 152,
okay. Continue turning left.

NARRATOR: In the confusion
over the turn, no one notices

that the Airbus is dropping
dangerously close to the ground.

Ultimately, the warning that
should alert them to the danger

never sounds.

CAPT. WIYOGO: What?
Come on, climb! Climb!

FO. ZUWALDI: Pull
up! Pull up! Pull up!

CAPT. WIYOGO: No! No!
No! No! No! Nooooo!

♪

NARRATOR: In their final report,
Indonesian investigators

call for improved communications
training for pilots

as well as upgrades
to Medan's radar system.

They also advise against
using the same flight number

for more than one
plane on the same route.

ROBERT: I think what really hit
home to me about this accident

and the loss of so many
lives was how avoidable it was.

SANTOSO: At the end of the
investigation, we were surprised

that there were
so many human errors

that happened one after another.

DAVID: All of these
things came together

to make an accident
very much more likely.

If you took away any
one of those factors,

the accident might
not have happened.