Original subtitles

♪

NARRATOR: Violent turbulence rocks Garuda Flight 421.

CPT. ROZAQ: Where did this come from? Strap in!

CPT. ROZAQ (translated): The shaking was so violent

I almost lost control of the plane.

NARRATOR: Terrified passengers just want the nightmare to end.

SUTJI (translated): I was scared. Extremely scared.

NARRATOR: Instead, the white-knuckle ride gets much worse.

FO. GUNAWAN: Engine one flamed out. And engine two flamed out.

KEVIN: You're in extreme dire circumstances

when you have a dual engine flameout.

NARRATOR: The 56-ton jet is falling from the sky.

CPT. ROZAQ: Please forgive our sins

and let us have the strength to save our passengers.

CPT. ROZAQ (translated): I felt that death was really upon us.

We were about to face our fate. And so we prayed.

Flight attendant: LADIES AND GENTLEMEN, WE ARE STARTING OUR APPROACH.

Pilot: WE LOST BOTH ENGINES!

Flight attendant: PUT THE MASK OVER YOUR NOSE.

EMERGENCY DESCENT.

Pilot: MAYDAY, MAYDAY.

Flight attendant: BRACE FOR IMPACT!

Controller: I THINK I LOST ONE.

Man: INVESTIGATION STARTING INTO THIS TRAGEDY...

Man: HE'S GONNA CRASH!

♪

NARRATOR: A Boeing 737 cruises high

above the islands of Indonesia.

The crew of Garuda Indonesia 421

is about halfway through a short domestic flight.

CPT. ROZAQ (translated): We were at 28,000 feet

on the way to Adisucipto Airport in Yogyakarta.

NARRATOR: Captain Abdul Rozaq is a senior pilot

with Indonesia's national airline.

CPT. ROZAQ: How does the weather look in Yogyakarta?

NARRATOR: His first officer is Harry Gunawan.

FO. GUNAWAN: It should be fine, but there might be a bit of rain.

CPT. ROZAQ (translated): I had flown several times with Harry Gunawan,

so it was nothing new.

We knew each other quite well.

♪

NARRATOR: Today, the cabin crew

is responsible for 54 passengers.

TUHU: Madam, can I offer you a drink?

SUTJI: Yes. I'll have tea please.

NARRATOR: Tuhu Wasono has been a Garuda flight attendant

for sixteen years.

TUHU (translated): Everything was normal.

We offered food and drinks for the passengers.

We checked the cabin and we chatted.

SUTJI: Thank you.

NARRATOR: Sutji Suharjanti is a senior government official

on her way to an important meeting.

SUTJI (translated): Because of work I fly often,

and I have done so since the 70s.

I really love flying.

NARRATOR: The flight is a sixty-minute trip from Mataram

on the resort island of Lombok

to Yogyakarta on the main island of Java.

January is the rainy season when the weather is unpredictable.

CPT. ROZAQ: Let's avoid that cell. Say, heading 300.

Control, Garuda 421.

Request heading 3-0-0 to avoid some weather up ahead.

AIR TRAFFIC CONTROLLER: Garuda 421, confirmed heading 3-0-0.

Fly direct to Bravo-Alpha-N-D-B after clearing weather.

NARRATOR: Air traffic control authorizes

a slight course correction

to steer the plane around some looming clouds.

TUHU (translated): The weather was just like any other afternoon.

There was no turbulence.

We could see from the cabin that it was bright outside.

It was very normal.

NARRATOR: But soon more large storm clouds appear

in their path.

FO. GUNAWAN: What do you think?

CPT. ROZAQ (translated): I could see the green, yellow and red on the radar,

and I knew that the safest route would be towards the green.

CPT. ROZAQ: I think we just veer a little to the left into that green gap.

We should be fine.

NARRATOR: The weather ahead could make for a bumpy ride.

♪

CPT. ROZAQ: Prepare the cabin for a little turbulence.

Hopefully it won't be too rough.

TUHU: Yes, Captain.

NARRATOR: As a precaution, the passengers are advised

to fasten their seat belts.

SUTJI (translated): I never thought it was something unusual.

I have been asked to put my seat belt on many times before.

TUHU: Seat belts. Can I just get you to do up your seat belt?

CPT. ROZAQ: Garuda 421.

Request clearance to descend to flight level 1-9-0.

AIR TRAFFIC CONTROLLER: Garuda 421, you are cleared to 1-9-0.

NARRATOR: The Garuda flight is now set to begin its approach.

So controllers clear them to descend.

But moments later, the weather is suddenly much worse.

♪

CPT. ROZAQ: Where did this come from?

Well, we're in it now. Strap in.

CPT. ROZAQ (translated): I had directed the plane towards the green,

but as soon as I entered the cloud everything went red.

KEVIN: This was a massive super cell.

It encompassed a large amount of area

that the pilots were forced to navigate in.

CPT. ROZAQ (translated): I was extremely surprised.

We'd already entered the cloud so, like it or not,

we had to go through the storm.

♪

NARRATOR: The sudden turbulence is far worse

than anyone in the cabin was expecting.

♪

SUTJI (translated): We started to feel the plane shaking violently,

and some people started to scream.

TUHU (translated): The turbulence made walking impossible.

The trays were flying around.

I was afraid I'd fall on someone.

♪

CPT. ROZAQ (translated): The shaking was so violent

I almost lost control of the plane.

CPT. ROZAQ: The engines!

NARRATOR: The captain spots a serious problem.

FO. GUNAWAN: Yes sir. One and two are dropping.

NARRATOR: They're suddenly losing engine power.

CPT. ROZAQ: Increasing thrust.

♪

FO. GUNAWAN: Nothing.

CPT. ROZAQ: Keep your eyes on them.

FO. GUNAWAN: Sir.

NARRATOR: Moments later, the crisis gets even worse.

FO. GUNAWAN: Engine one flamed out!

CPT. ROZAQ: Confirmed. GPW ALARM: Terrain. Terrain.

FO. GUNAWAN: And engine two flamed out.

NARRATOR: Both engines have flamed out,

the combustion process extinguished.

KEVIN: You're in extreme dire circumstances

when you have a dual-engine flameout.

NARRATOR: The plane now has no thrust at all.

Inside, they've lost primary electricity.

All systems switch to backup power.

TUHU (translated): All of a sudden the emergency lights came on.

I was shocked to see that.

NARRATOR: Captain Rozaq struggles to keep the plane steady

as the altitude starts to drop.

CPT. ROZAQ (translated): I immediately yelled for the emergency checklist.

CPT. ROZAQ: Perform engine flameout procedure.

Engine start switches to flight.

FO. GUNAWAN: Engine start switches to flight.

CPT. ROZAQ: Start levers to cutoff.

FO. GUNAWAN: Start levers to cutoff.

KEVIN: You take both start levers for both the number one

and the number two engine

and put them back in the run position,

and then you wait to see if the engines light off.

FO. GUNAWAN: Timing, thirty seconds.

♪

NARRATOR: The restart procedure demands patience.

CPT. ROZAQ (translated): We timed it for thirty seconds,

as is the protocol,

and waited for them to light up.

♪

SUTJI: Please, God. Just to see my family again.

Please, help us, God. Just to see my family again.

SUTJI (translated): I thought I probably wouldn't see

my husband or children again.

I was praying for God to help me

because I wasn't ready to die.

♪

NARRATOR: By now, the engines should have restarted.

FO. GUNAWAN: Relight failed.

NARRATOR: But both of them are still dead.

CPT. ROZAQ: Try it again. FO. GUNAWAN: Okay. Let's go.

CPT. ROZAQ: Engine start switches to flight.

FO. GUNAWAN: Engine start switches to flight.

NARRATOR: The plane is now dropping a thousand feet

every fifteen seconds.

KEVIN: That's an extreme emergency.

FO. GUNAWAN: Timing, thirty seconds.

KEVIN: You have very little options,

and immediate action is required.

♪

♪

FO. GUNAWAN: Nothing.

NARRATOR: For the second time, the Garuda pilots try and fail

to restart their crippled engines.

Now only minutes from hitting the ground,

they're running out of options.

CPT. ROZAQ (translated): After the engines wouldn't start a second time,

I knew we still had our auxiliary power unit,

the APU.

KEVIN: The APU is a jet fuel powered generator

that provides electrical power for the aircraft.

NARRATOR: The APU may be their only hope.

CPT. ROZAQ: Start APU. FO. GUNAWAN: Start APU.

NARRATOR: But as they try to start it...

FO. GUNAWAN: We've lost all power!

NARRATOR: ...catastrophe strikes.

CPT. ROZAQ (translated): When he tried to turn on the standby generator,

everything shut down.

CPT. ROZAQ: Okay. Figure it out!

CPT. ROZAQ (translated): Electricity was gone.

Flight instruments, gone.

Everything went dark.

I had no tools to fly the plane.

NARRATOR: Controllers are stunned to see Flight 421 vanish from radar.

AIR TRAFFIC CONTROLLER: Garuda 4-2-1, do you read me?

4-2-1, please report your position.

♪

FO. GUNAWAN: Mayday. Mayday. Mayday! Garuda 4-2-1 Mayday!

CPT. ROZAQ (translated): We were still within the severe turbulence.

We had tried everything in the book.

So my co-pilot grabbed the mic and yelled,

"Mayday, mayday, mayday."

FO. GUNAWAN: Mayday, mayday, mayday. Garuda 4-2-1. Mayday!

NARRATOR: But controllers can't hear the desperate call.

AIR TRAFFIC CONTROLLER: Garuda 4-2-1, do you read me?

Please report your position.

♪

FO. GUNAWAN: Mayday! Mayday! Mayday! Garuda 4-2-1.

NARRATOR: They've lost all contact with the stricken plane.

SUTJI (translated): I heard, "Mayday, mayday."

Then I overheard they were saying, "No power, no power."

CPT. ROZAQ: No power, no radio.

SUTJI (translated): That's when I realized the plane had no working engine.

Everything was off.

CPT. ROZAQ: No power. No radio. What do we have?

FO. GUNAWAN: Emergency instruments only.

KEVIN: They would have the standby attitude indicator

or horizon, the standby airspeed indicator

and a magnetic compass.

CPT. ROZAQ: We're in God's hands now.

♪

NARRATOR: The pilots pray for help.

CPT. ROZAQ: Please, forgive our sins

and let us have the strength to save our passengers.

CPT. ROZAQ (translated): I felt that death was really upon us.

We were about to face our fate.

And so we prayed.

SUTJI (translated): I was scared, extremely scared. I said some prayers.

I asked God to help us.

I prayed my last rites and begged for God's forgiveness.

I kept praying and praying.

That's all I could do.

♪

NARRATOR: The 56-ton jet with no power is falling fast.

But the pilots aren't giving up.

CPT. ROZAQ: Let's see if we can find ourselves an airport.

KEVIN: The airplane would be gliding.

It would be losing altitude, but the airplane continues to fly

whether the engines are running or not.

CPT. ROZAQ: Confirm our optimal speed for drift down.

FO. GUNAWAN: Yes, sir.

CPT. ROZAQ (translated): I actually couldn't see the standby instruments.

They were so small.

So I had to rely on my co-pilot.

FO. GUNAWAN: Drift down airspeed 2-1-2 knots.

CPT. ROZAQ: 2-1-2. Current speed please.

FO. GUNAWAN: 2-3-5.

You need to lose speed.

KEVIN: It would be very challenging to try to land a 737

without power and without any type of assistance.

♪

NARRATOR: At roughly eight thousand feet,

Garuda Flight 421 finally escapes the storm.

CPT. ROZAQ: Okay. Let's figure out where we are.

♪

NARRATOR: But the captain's task still seems impossible --

landing a plane with no engines and no electronic guidance.

CPT. ROZAQ (translated): I didn't even know where we were

because my instruments were dead.

FO. GUNAWAN: We're near the Solo River, sir.

CPT. ROZAQ: Where's the airport? Quickly.

FO. GUNAWAN: We've passed it, sir.

NARRATOR: The nearest airport is now behind them,

and they're too low to circle back.

They've missed their last chance for a controlled landing.

CPT. ROZAQ: We have to land somewhere.

Let's see what we've got.

CPT. ROZAQ (translated): The plane weighs 56 tons.

You can imagine how fast we were descending.

We had to decide in seconds where we could land the plane.

♪

NARRATOR: Dropping lower and lower, the crew of Garuda 421

scrambles to find somewhere to land.

FO. GUNAWAN: The rice field, sir!

CPT. ROZAQ: Negative. Too risky.

KEVIN: Landing in the rice paddy

could have cartwheeled the airplane.

It could have made the airplane

break in several pieces as well.

NARRATOR: With his plane falling fast

and no other option in sight,

Captain Rozaq decides to do something few pilots

have ever tried.

CPT. ROZAQ: Okay. The river then. It's our best chance.

FO. GUNAWAN: Yes, sir. Tell me what to do.

CPT. ROZAQ: No gear, no flaps. Watch my speed.

NARRATOR: The Solo River is narrow and twisting.

Ditching a 737 on it won't be easy.

CPT. ROZAQ: But I believed the plane

would suffer less from the impact

and we'd have a better chance of surviving.

NARRATOR: But there's another obstacle.

CPT. ROZAQ: Bridge!

FO. GUNAWAN: Can we go under it, sir?

CPT. ROZAQ: No.

CPT. ROZAQ (translated): I wanted to pass under the bridge.

But I could make out

that there were concrete pillars underneath it.

FO. GUNAWAN: Three thousand feet.

NARRATOR: Captain Rozaq makes a split second decision.

CPT. ROZAQ: Let's circle around and put it down over there.

Turn with me!

FO. GUNAWAN: Turning.

NARRATOR: Looping back could give them

a longer stretch of river to land on.

But they're running out of time.

In order to turn, the aircraft relies on its hydraulic system.

And the hydraulics need engine power.

KEVIN: A large amount of force is required without hydraulics.

It would be the equivalent of trying to drive your car

without power steering assistance.

FO. GUNAWAN: Bank angle, sir. Look!

CPT. ROZAQ: I see. I see. I see.

Keep turning or we don't make the river. Turn hard!

CPT. ROZAQ (translated): My co-pilot shouted out

because he felt the turn was too sharp.

But I told him we have no choice.

If we don't do this, we will not make it to the river.

SUTJI (translated): For the first time I saw a river,

a bridge and rice fields.

But I was confused. There was no runway.

♪

CPT. ROZAQ: Speed? FO. GUNAWAN: 1-7-0, sir.

CPT. ROZAQ: That'll do.

NARRATOR: As they line up with the river,

First Officer Gunawan notices another problem.

FO. GUNAWAN: There's another bridge!

CPT. ROZAQ: Altitude? FO. GUNAWAN: 250.

CPT. ROZAQ: The bridge can't be more than 80 feet. We're good.

CPT. ROZAQ (translated): It turns out I had to land the plane

between two bridges.

FO. GUNAWAN: 150!

CPT. ROZAQ: Warn the cabin. Brace for landing.

FO. GUNAWAN: Brace for landing. Brace for landing.

TUHU: Brace for landing. Everyone, brace for landing.

♪

CPT. ROZAQ: Okay, okay, okay. Here we go.

FO. GUNAWAN: 50! 40!

Help us, God. 30!

♪

CPT. ROZAQ: Brace!

CPT. ROZAQ (translated): From the beginning, I had left it all to God.

I had no more fear.

I had hopes that I could survive this

and that the passengers would be saved too.

NARRATOR: Flight 421 hits the water

at almost 200 miles an hour.

CPT. ROZAQ: Are you okay? FO. GUNAWAN: Ah. Alive.

NARRATOR: The cabin of Flight 421 has been demolished.

♪

TUHU (translated): When the plane finally stopped

after the emergency landing, I was very relieved and grateful.

♪

SUTJI (translated): I wondered if there was blood on my feet.

It turned out it was just water.

I said, "thank God I survived."

♪

TUHU (translated): I began the evacuation process.

I helped the passengers who were near me

at the front of the plane.

♪

♪

CPT. ROZAQ: Thank you, God.

Let's check on the passengers.

NARRATOR: From the emergency exit,

passengers can wade safely to shore.

CPT. ROZAQ (translated): I was the last person to leave the plane.

NARRATOR: Of the sixty passengers and crew on board,

all but one make it out alive.

KEVIN: I'm very surprised there was only one fatality.

It's a sheer miracle

that more people did not perish in the accident.

♪

NARRATOR: Despite the skillful landing,

the sight of a 737 ditched in an Indonesian river

is disturbing.

As crews remove wreckage from the Solo River,

the nation looks for answers.

How could a state-of-the-art airplane

simply shut down in midair?

NARRATOR: The job of figuring out what brought down Garuda Flight 421

falls to a team of Indonesian investigators.

Their first priority is to recover the plane's black boxes.

RAY: It will reveal all the information we need,

all of the engine behavior, all of the pilot communications,

so we really, really need this black box.

NARRATOR: While they wait for word on the flight recorders,

investigators meet with Captain Rozaq.

RAY: Thank you for coming, captain.

NARRATOR: They want to learn more

about the pilot behind this landing.

CPT. ROZAQ: Thank you.

NARRATOR: He has 14,000 hours of flying time.

But getting here was not easy.

Growing up poor, he sold vegetables in the streets

of Jakarta, his family unable to afford school.

CPT. ROZAQ (translated): My only chance for an education

was to win a scholarship.

There were thousands of people who applied

to the national flight school,

and I was lucky enough to be one of the 56 students

who graduated in my year.

NARRATOR: Captain Rozaq quickly rose

through the ranks at Garuda.

CPT. ROZAQ (translated): I was extremely happy to join

the biggest airline in Indonesia.

It was a dream come true.

RAY: So can you tell me exactly what happened?

CPT. ROZAQ: I've never experienced an engine flameout before.

I thought these engines could handle anything.

RAY: My first big question is what caused the engines

to flame out simultaneously.

RAY: Why couldn't you relight them?

CPT. ROZAQ: We tried. Maybe they had a fault?

It didn't make sense.

♪

NARRATOR: The downed Boeing plane was equipped

with two CFM 56 engines,

one of the most advanced turbo fan designs in the world.

The power plant draws in cold air with a large fan

at the inlet.

A series of blades then compress some of the air

before it's mixed with fuel and ignited in the burner.

Combustion spins turbines in the core that drive the engine

and push hot exhaust gases out of the rear nozzle

at high speed.

KEVIN: So there's probably four to six thousand CFM56

in use at the moment.

It's a very reliable engine and has a very good history.

RAY: Let's take a look at the occurrence manual.

♪

NARRATOR: But as investigators learn, even the best engine

isn't foolproof.

ERTATA (translated): There were some cases with similar aircraft

where the engine flamed out.

NARRATOR: In 1988, TACA Flight 110 got caught

in a violent thunderstorm flying from Belize to New Orleans.

Both engines on the brand new 737 flamed out.

The pilot managed to make an emergency landing

on a grass-covered levy.

Investigators discover that

in response to the near disaster with the TACA flight,

the manufacturer redesigned the engine.

A new design changed the shape of the spinner

and increased the distance

between the fan motor and the splitter

to better deflect moisture from the core.

KEVIN: They found that the dome shape worked better

for both ice and hail.

NARRATOR: So why did this redesigned engine now fail?

RAY: See, it doesn't make any sense.

RAY: I was surprised that the dual-engine flameout

occurred to the engine

that has been modified for precipitations.

NARRATOR: Engineers run a series of tests on the two engines.

They're looking for any defect

that might explain the midair failure.

♪

They find nothing. No mechanical faults of any kind.

RAY: Everything seems to be good.

RAY: My opinion was that the engine,

including the modification, was working as designed.

So my question was,

what caused the engines to flame out?

NARRATOR: At the crash site, a new development

brings hope of finding some answers.

Divers have recovered the aircraft's flight data recorder.

♪

RAY: Let's take a look at this.

NARRATOR: Investigators focus

on the engine performance numbers.

RAY: Now check out the fuel flow right here.

NARRATOR: The data shows that when the plane entered the storm,

fuel consumption shot up.

But despite the higher fuel flow,

engine speed remained constant.

RAY: And yet the engine rotation remains the same

and does not increase.

NARRATOR: It tells investigators that the engines

were working hard battling against the heavy rainstorm.

KEVIN: Fuel flow would go up because of the ingested water

because it increased air density.

RAY: And then suddenly the engines died. What changed?

NARRATOR: The plane's engines were specifically designed

to handle large volumes of water.

Investigators see nothing in the data

to explain why they suddenly cut out.

What went wrong is still a mystery.

But just as one lead fails to pan out, another turns up.

Searchers pull the cockpit voice recorder

from the mud of the Solo River.

♪

RAY: So...

let's hear what was happening inside the cockpit.

Are you plugged in? Go ahead.

CPT. ROZAQ: Let's avoid that cell. Say heading 300.

NARRATOR: At the start of the recording, the audio quality is good.

CPT. ROZAQ: Control, Garuda 421 requesting heading 3-0-0.

FO. GUNAWAN: Yes, sir! Number two as well.

CVR:

RAY: Whoa. Turn it down a bit.

NARRATOR: But soon noise from the pounding storm

makes it almost impossible to decipher sounds

in the cockpit.

RAY: Can you isolate the voices?

NARRATOR: Investigators can no longer make out

what the pilots are saying.

KEVIN: They were unable to filter the exterior noise out

to listen to the conversation of the pilots

because it was that severe. It was super, super loud.

RAY: When we listened to the CVR

it's really hard to understand.

CVR:

RAY: Stop. Rewind.

CVR:

RAY: Try again.

NARRATOR: Then, in the last seconds of the recording,

a non-human voice can be heard.

GPW ALARM: Terrain. Terrain. Terrain.

RAY: It's saying terrain.

GPW ALARM: Terrain. Terrain.

RAY: It's a ground proximity warning.

NARRATOR: Investigators have stumbled across a huge clue.

GPW ALARM: Terrain. Terrain. Terrain. Terrain.

FO. GUNAWAN: Terrain? GPW ALARM: Terrain.

CPT. ROZAQ: No, not terrain. It can't be.

NARRATOR: At 18,000 feet, the onboard computer

detected something solid below the plane,

something as solid as terrain.

RAY: When I heard, "Terrain, terrain," I was surprised.

First, there was no terrain the area.

RAY: There's no amount of rain in the world

can trigger that warning. What was happening?

NARRATOR: Indonesian investigators struggle to understand

why a terrain warning sounded aboard Garuda 421

when the aircraft was still at 18,000 feet.

Amid the wreckage, the plane's nose cone, or radome,

provides a critical clue.

RAY: Come see this for a sec.

KEVIN: It was beat up pretty bad.

It had almost looked like someone

had gone out with a ball peen hammer

and took aggression out on the radome of the aircraft.

RAY: Look at these.

ERTATA (translated): I'd never seen this before.

RAY: There's only one thing this could be. Hail.

NARRATOR: It's now clear that the violent storm

the crew encountered contained enough hail to

damage the nose and to trigger the ground proximity warning.

GPW ALARM: Terrain. Terrain.

KEVIN: The hail was estimated to be the size of tennis balls,

which is enormous and detrimental to the aircraft.

NARRATOR: Part of the engines' recent modifications

had specifically to do with hail.

KEVIN: The engine is designed to handle

ten grams per meter cubed, a fairly large amount

of precipitation.

NARRATOR: Investigators wonder:

Did the massive storm throw more rain and hail than that

at Flight 421's engines?

They take the sound of the rain and hail hitting

the Garuda cockpit at the moment the engines flamed out

and compare it with cockpit recordings of other flights

hit by severe storms.

♪

RAY: None of these numbers match up.

NARRATOR: The comparison shows that the Garuda flight

flew into precipitation heavier than any storm ever recorded.

The loudness of the storm

along with the engines' performance data

tells investigators how much rain and hail

the 737 likely encountered.

RAY: That's insane.

RAY: And based on our tests we conclude

that the amount of ice

was more than 18 grams per cubic meter.

KEVIN: These engines were well in excess

of the manufacturer's tested criteria.

It was almost double the amount of precipitation,

water and hail ingested into the engine.

NARRATOR: Investigators have compiled convincing data

on what caused the dual-engine flameout.

But to be absolutely sure,

they want to put their analysis to the test.

RAY: Engines power on.

Okay. Let's add some water and ice.

KEVIN: The NTSC wanted to determine how much water

was actually ingested and if the engine would continue running.

So they went and sprayed to the inlet of the engine

the manufacturer's recommended amount,

and the engine ran perfectly.

RAY: Bringing it up now.

KEVIN: They took the engine and increased the water flow

into the inlet of the engine to what was calibrated

that they had experienced during the flight.

♪

RAY: I think we have our answers here why the engines died.

NARRATOR: The engine test leaves no doubt.

KEVIN: That was a big aha moment for them,

because adding the ice to the water caused the engine

to finally stop.

NARRATOR: A violent storm combining heavy rain and giant hail

extinguished both engines on Flight 421.

But the investigation isn't over.

There's another mystery still to solve.

Why did Flight 421 fly into such a severe storm

in the first place?

Why were the 737's advanced navigation systems...

CPT. ROZAQ: Let's avoid that cell.

NARRATOR: ...not enough to help the crew steer clear

of dangerous weather?

Investigators review the satellite weather data

from the day of the crash.

RAY: Let me just take a look at this radar map again. Okay.

So...

your track took you straight into the worst part

of the storm.

ERTATA (translated): Why did Captain Rozaq choose such a dangerous route?

NARRATOR: The plane's weather radar

should have helped them find a way around the storm.

RAY: Why would you enter the storm? Why not detour?

CPT. ROZAQ: I think we just veer a little to the left

into that green gap. We should be fine.

KEVIN: The pilots were under the impression

that they had an opening

that went all the way through the weather.

CPT. ROZAQ: The radar showed green. We should have been safe.

RAY: Why would your radar indicate a safe passage?

CPT. ROZAQ: I don't know.

But suddenly everything changed.

NARRATOR: It seems the radar didn't pick up the danger ahead.

CPT. ROZAQ: Where did this come from?

KEVIN: The alley that they were trying to go down

closed up on them and was not the good flight path

that they were hoping for.

NARRATOR: Investigators need to know why.

CPT. ROZAQ: Strap in.

RAY: So this...

NARRATOR: They consult a radar expert.

RAY: ...is where they entered the storm.

NARRATOR: And learn that pilots can face the dangers

of something called radar shadowing.

KEVIN: Radar shadowing is the radar's inability

to identify other weather that could be in front of you

that you're trying to avoid.

RAY: Radar shadow?

NARRATOR: Radar shadows occur when precipitation is so severe

radio waves can't penetrate the skies ahead.

A shadow appears on the pilot's screen as a dark gap.

KEVIN: So it would be deceiving

that you were flying into some good weather,

and in reality you would...

you were entering into another severe storm.

NARRATOR: The Garuda plane's dangerous flight path

finally makes sense.

RAY: So what you're saying is they sought refuge

on the radar shadow.

NARRATOR: The crew didn't realize they were flying

into weather severe enough to knock out their engines.

But there's still one unanswered question.

The hailstorm killed the engines.

FO. GUNAWAN: Start APU.

NARRATOR: But what killed the 737's power supply?

FO. GUNAWAN: We've lost all power.

ERTATA (translated): The plane lost its electrical supply,

which means there was no power left on board at all.

We were very concerned

and needed to find out why this happened.

♪

NARRATOR: Investigators know that Garuda Flight 421

somehow lost all electrical power.

RAY: If they hadn't lost power,

they could have restarted the engines

once they were outside the storm.

What happened?

NARRATOR: But they still don't understand how that happened.

RAY: Thanks for coming, Captain. Please, have a seat.

NARRATOR: Investigators hope Captain Rozaq

can remember some overlooked detail.

RAY: I just have a few more questions.

Now take us through exactly what happened

after the engines flamed out.

CPT. ROZAQ: As soon as the engines died,

we followed the relight procedure.

CPT. ROZAQ: Engine start switches to flight.

FO. GUNAWAN: Engine start switches to flight.

CPT. ROZAQ: Start levers to cutoff.

FO. GUNAWAN: Start levers to cutoff.

KEVIN: They followed procedure to the penny.

FO. GUNAWAN: Relight failed.

NARRATOR: When the engines didn't relight,

they tried to start the auxiliary power unit

to restore electricity to the entire plane.

RAY: And then what happened?

CPT. ROZAQ: Disaster.

CPT. ROZAQ: Start APU.

FO. GUNAWAN: Start APU.

♪

We've lost all power.

KEVIN: Unfortunately, after two attempts

to restart the engines and trying to start the APU

it depleted the battery.

NARRATOR: Heavy-duty aircraft batteries

almost never die mid-flight. So why did this one?

The captain doesn't have the answer.

But he does provide one very important clue.

RAY: Is there anything else that you can remember?

CPT. ROZAQ: The battery voltage was low,

22 volts,

even before we initiated the restart sequence.

It seemed odd but we didn't have time to think about it.

ERTATA (translated): When I was interviewing Captain Rozaq,

he mentioned the battery capacity was just 22 volts

when he tried to revive the engines.

RAY: Twenty-two is within the limit, but it's the lowest value,

so it's considered to be weak.

NARRATOR: A fully charged battery in a 737 has 24 volts.

RAY: Are you sure it's 22, not 24?

CPT. ROZAQ: 22 volts. I remember.

KEVIN: Another two volts might have made the difference

in getting the engines started

or getting the APU started.

NARRATOR: Four weeks after the crash, searchers pull

what could be the last piece of the investigative puzzle

from the Solo River,

the battery from Flight 421.

One of its 20 cells shows signs of damage

from before the crash, evidence that seems consistent

with the captain's observations.

RAY: We found the cell condition was one of the most damaged,

and it reduced the battery capability

quite significantly.

NARRATOR: But how significant was the damage?

Was the battery too weak to restart a flamed out engine?

Investigators stage a test to find out.

RAY: Let's start water and ice up to 18 grams per cubic meter.

NARRATOR: They replicate the flight conditions

and follow the exact procedure the pilots used

trying to restart their engines.

♪

RAY: Okay. Initiate restart engine procedure.

CPT. ROZAQ: Engine start switches to flight.

FO. GUNAWAN: Engine start switches to flight.

CPT. ROZAQ: Start levers to cutoff.

FO. GUNAWAN: Start levers to cutoff.

CPT. ROZAQ: Start levers to idle.

FO. GUNAWAN: Start levers to idle.

Timing 30 seconds.

RAY: 28, 29, 30.

Okay. First attempt failed.

Battery to 20 volts.

Keep precipitation ready and let's see what happens

to the battery in a second attempt, all right?

So we'll start timing once again. And we're going.

CPT. ROZAQ: Try it again. Engine start switches to flight.

FO. GUNAWAN: Engine start switches to flight.

CPT. ROZAQ: Start levers to idle.

FO. GUNAWAN: Start levers to idle. Timing 30 seconds.

RAY: 28, 29, 30.

Battery has dropped to 12 volts,

making it practically useless.

And now try to start the APU. CPT. ROZAQ: Start APU.

FO. GUNAWAN: Start APU.

We've lost all power.

RAY: They had no chance.

The restart procedure completely drained their faulty battery.

RAY: It was not capable to support the engine restart

in emergency conditions.

NARRATOR: Finally, investigators understand

all the contributing factors that knocked Flight 421

from the sky.

CPT. ROZAQ: I think we just veer a little to the left

into that green gap. We should be fine.

NARRATOR: A shadow effect on the radar leads the crew

to mistake the worst of the storm for a clear path.

The storm hits them with hail so severe the engines flame out.

CPT. ROZAQ: Perform engine flameout procedure.

Engine start switches to flight.

FO. GUNAWAN: Engine start switches to flight.

NARRATOR: Efforts to relight the engines

drain valuable power from a damaged battery.

Without power, with their plane dropping fast

far from any airport, it was only Captain Rozaq's

incredible airmanship

that prevented a total disaster.

In their official report, investigators recommend

better radar training for flight crews

to help them navigate extreme weather.

They also call for new procedures for flying

in heavy rain and hail with the CFM 56 engine,

such as increasing the throttle setting when entering a storm.

In recognition of their heroism, Captain Abdul Rozaq

and First Officer Harry Gunawan

receive congratulations from the Indonesian president.

CPT. ROZAQ (translated): It's the biggest honor

I will ever receive in my life.

NARRATOR: Beyond the public recognition,

the crew has received enduring gratitude.

TUHU (translated): He saved so many lives onboard the plane.

For that, I salute Captain Rozaq.

SUTJI (translated): We felt the two of them were chosen by God

to bring us to safety on the river.

They were our heroes.

♪