Mayday (2013) s16e08 Episode Script
River Runway
Violent turbulence rocks Garuda Flight 421.
Where did this come from? Strap in.
TRANSLATION: The shaking was so violent, I almost lost control of the plane.
Terrified passengers just want the nightmare to end.
TRANSLATION: I was scared.
Extremely scared.
Instead, the white-knuckle ride gets much worse.
Engine one flamed out! And engine two flamed out! You're in extreme dire circumstances when you have a dual - engine flameout.
- The 56-ton jet is falling from the sky.
Please forgive our sins.
Let us have the strength to save our passengers.
TRANSLATION: I felt that death was really upon us.
We were about to face our fate.
And so we prayed.
A Boeing 737 cruises high above the islands of Indonesia.
The crew of Garuda Indonesia 421 is about halfway through a short domestic flight.
TRANSLATION: We were at 28,000 feet on the way to Adisucipto Airport in Yogyakarta.
Captain Abdul Rozaq is a senior pilot with Indonesia's national airline.
How does the weather look in Yogyakarta? His first officer is Harry Gunawan.
It should be fine but there might be a bit of rain.
TRANSLATION: I had flown several times with Harry Gunawan, so it was nothing new.
We knew each other quite well.
Today, the cabin crew is responsible for 54 passengers.
Madam, can I offer you a drink? Yes.
I'll have tea, please.
Tuhu Wasono has been a Garuda flight attendant for 16 years.
TRANSLATION: Everything was normal.
We offered food and drinks for the passengers.
We checked the cabin and we chatted.
- Thank you.
- Sutji Suharjanti is a senior government official on her way to an important meeting.
TRANSLATION: Because of work I fly often and I have done so since the '70s.
I really love flying.
The flight is a 60 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.
Let's avoid that cell.
Say heading 300.
Control, Garuda 421.
Request heading 300 to avoid some weather up ahead.
Garuda 421, confirmed heading 300.
Fly direct to Bravo Alpha NDB after clearing weather.
Air traffic control authorises a slight course correction to steer the plane around some looming clouds.
TRANSLATION: 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.
But soon more large storm clouds appear in their path.
What do you think? TRANSLATION: I could see the green, yellow and red on the radar and I knew that the safest route would be towards the green.
I think we just veer a little to the left into that green gap.
We should be fine.
The weather ahead could make for a bumpy ride.
Prepare the cabin for a little turbulence.
- Hopefully it won't be too rough.
- Yes, captain.
As a precaution, the passengers are advised to fasten their seatbelts.
TRANSLATION: I never thought it was something unusual.
I've been asked to put my seatbelt on many times before.
Seatbelts.
Can I just get you to do up your seatbelt? Garuda 421.
Request clearance to descend to flight level 190.
Garuda 421, you are cleared to 190.
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.
Where did this come from? Well, we're in it now.
Strap in.
TRANSLATION: I had directed the plane towards the green, but as soon as I entered the cloud everything went red.
This was a massive super cell.
It encompassed a large amount of area that the pilots were forced to navigate in.
TRANSLATION: I was extremely surprised.
We'd already entered the cloud so, like it or not, we had to go through the storm.
The sudden turbulence is far worse than anyone in the cabin was expecting.
TRANSLATION: We started to feel the plane shaking violently and some people started to scream.
TRANSLATION: The turbulence made walking impossible.
The trays were flying around.
I was afraid I'd fall on someone.
TRANSLATION: The shaking was so violent, I almost lost control of the plane.
The engines! The captain spots a serious problem.
Yes, sir.
One and two are dropping.
They're suddenly losing engine power.
Increasing thrust! Nothing.
- Keep your eyes on them.
- Sir.
Moments later, the crisis gets even worse.
Engine one flamed out! Confirmed.
Terrain.
And engine two flamed out.
Both engines have flamed out, the combustion process extinguished.
You're in extreme dire circumstances when you have a dual engine flameout.
The plane now has no thrust at all.
Inside, they've lost primary electricity.
All systems switch to backup power.
TRANSLATION: All of a sudden the emergency lights came on.
I was shocked to see that.
Captain Rozaq struggles to keep the plane steady as the altitude starts to drop.
TRANSLATION: I immediately yelled for the emergency checklist.
Perform engine flameout procedure.
- Engine start switches to flight.
- Engine start switches to flight.
- Start levers to cut-off.
- Start levers to cut-off.
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.
Timing, 30 seconds.
The restart procedure demands patience.
TRANSLATION: We timed it for 30 seconds, as is the protocol, and waited for them to light up.
Please, God.
Just to see my family again.
Please help us, God.
Just to see my family again.
TRANSLATION: 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.
By now, the engines should have restarted.
- Relight failed.
- But both of them are still dead.
- Try it again.
- OK.
Let's go.
Engine start switches to flight.
Engine start switches to flight.
The plane is now dropping 1000 feet every 15 seconds.
- That's an extreme emergency.
- Timing, 30 seconds.
You have very little options, and immediate action is required.
Nothing.
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.
TRANSLATION: After the engines wouldn't start a second time, I knew we still had our auxiliary power unit, the APU.
The APU is a jet fuel-powered generator that provides electrical power for the aircraft.
The APU may be their only hope.
- Start APU.
- Start APU.
But as they try to start it - We've lost all power! - .
.
catastrophe strikes.
TRANSLATION: When he tried to turn on the standby generator, everything shut down.
OK.
Figure it out.
TRANSLATION: Electricity was gone.
Flight instruments, gone.
Everything went dark.
I had no tools to fly the plane.
Controllers are stunned to see flight 421 vanish from radar.
Garuda 421, do you read me? 421, please report your position.
Mayday.
Mayday.
Mayday! Garuda 421 Mayday! TRANSLATION: We were still within the severe turbulence.
We had tried everything in the book.
So my copilot grabbed the mic and yelled, "Mayday, mayday, mayday.
" Mayday, mayday, mayday.
Garuda 421.
Mayday! But controllers can't hear the desperate call.
Garuda 421, do you read me? Please report your position.
Mayday! Mayday! Mayday! Garuda 421.
They've lost all contact with the stricken plane.
TRANSLATION: I heard "Mayday, mayday.
" Then I overheard they were saying "No power, no power.
" - No power, no radio.
- TRANSLATION: That's when I realized the plane had no working engine.
Everything was off.
No power.
No radio.
- What do we have? - Emergency instruments only.
They would have the standby attitude indicator, or horizon, the standby airspeed indicator and a magnetic compass.
We're in God's hands now.
The pilots pray for help.
Please forgive our sins and let us have the strength to save our passengers.
TRANSLATION: I felt that death was really upon us.
We were about to face our fate.
And so we prayed.
TRANSLATION: 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.
The 56 ton jet with no power is falling fast.
But the pilots aren't giving up.
Let's see if we can find ourselves an airport.
The airplane would be gliding.
It would be losing altitude, but the airplane continues to fly whether the engines are running or not.
Confirm our optimal speed for drift down.
- Yes, sir.
- TRANSLATION: I actually couldn't see the standby instruments.
They were so small.
So I had to rely on my copilot.
Drift-down airspeed 212 knots.
212.
Current speed, please.
You need to lose speed.
It would be very challenging to try to land a 737 without power and without any type of assistance.
At roughly 8000 feet, Garuda flight 421 finally escapes the storm.
OK.
Let's figure out where we are.
But the captain's task still seems impossible - landing a plane with no engines and no electronic guidance.
TRANSLATION: I didn't even know where we were because my instruments were dead.
We're near the Solo River, sir.
Where's the airport? Quickly.
We've passed it, sir.
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.
We have to land somewhere.
Let's see what we've got.
TRANSLATION: 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.
Dropping lower and lower, the crew of Garuda 421 scrambles to find somewhere to land.
- The rice field, sir! - Negative.
Too risky.
Landing in the rice paddy could have cartwheeled the airplane.
It could have made the airplane break in several pieces as well.
With his plane falling fast and no other option in sight, Captain Rozaq decides to do something few pilots have ever tried.
OK.
The river then.
It's our best chance.
Yes, sir.
Tell me what to do.
No gear, no flaps.
Watch my speed.
The Solo River is narrow and twisting.
Ditching a 737 on it won't be easy.
TRANSLATION: But I believed the plane would suffer less from the impact and we'd have a better chance of surviving.
But there's another obstacle.
Bridge! - Can we go under it, sir? - No.
TRANSLATION: I wanted to pass under the bridge.
But I could make out that there were concrete pillars underneath it.
3000 feet.
Captain Rozaq makes a split-second decision.
Let's circle around and put it down over there.
- Turn with me! - Turning.
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.
A large amount of force is required without hydraulics.
It would be the equivalent of trying to drive your car without - power-steering assistance.
- Bank angle, sir.
Look! I see.
I see.
I see.
Keep turning or we don't make the river.
Turn hard! TRANSLATION: 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.
TRANSLATION: For the first time I saw a river, a bridge and rice fields.
But I was confused.
There was no runway.
Speed? 170, sir.
- That'll do.
- As they line up with the river, First Officer Gunawan notices another problem.
There's another bridge! Altitude? The bridge can't be more than 80 feet.
We're good.
TRANSLATION: It turns out I had to land the plane between two bridges.
150! - Warn the cabin.
Brace for landing.
- Brace for landing! Brace for landing! Brace for landing.
Everyone, brace for landing! OK, OK, OK.
Here we go.
50! 40! Help us, God.
30! Brace! TRANSLATION: 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.
Flight 421 hits the water at almost 200 miles an hour.
- Are you OK? - Ah.
Alive.
The cabin of flight 421 has been demolished.
TRANSLATION: When the plane finally stopped after the emergency landing, I was very relieved and grateful.
TRANSLATION: I wondered if there was blood on my feet.
It turned out it was just water.
I said, "Thank God I survived.
" TRANSLATION: I began the evacuation process.
I helped the passengers who were near me at the front of the plane.
Thank you, God.
Let's check on the passengers.
From the emergency exit, passengers can wade safely to shore.
TRANSLATION: I was the last person to leave the plane.
Of the 60 passengers and crew onboard, all but one make it out alive.
I'm very surprised there was only one fatality.
It's a sheer miracle that more people did not perish in the accident.
Despite the skilful 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? 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.
It will reveal all the information we need, all of the engine behaviour, all of the pilot communications, so we really, really need this black box.
While they wait for word on the flight recorders, investigators speak to Captain Rozaq.
- Thank you for coming, captain.
- They want to learn more about - the pilot behind this landing.
- Thank you.
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.
TRANSLATION: 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.
Captain Rozaq quickly rose through the ranks at Garuda.
TRANSLATION: I was extremely happy to join the biggest airline in Indonesia.
It was a dream come true.
So can you tell me exactly what happened? I've never experienced an engine flameout before.
I thought these engines could handle anything.
My first big question is what caused the engines to flame out simultaneously.
- Why couldn't you relight them? - We tried.
Maybe they had a fault? It didn't make sense.
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.
So there's probably 4000 to 6000 CFM56 in use at the moment.
It's a very reliable engine and has a very good history.
Let's take a look at the occurrence manual.
But as investigators learn, even the best engine isn't foolproof.
TRANSLATION: There were some cases with similar aircraft where the engine flamed out.
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.
They found that the dome shape worked better for both ice and hail.
So why did this redesigned engine now fail? See, it doesn't make any sense.
I was surprised that the dual engine flameout occurred to the engine that has been modified for precipitations.
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.
Everything seems to be good.
My opinion was that the engine, including the modification, was working as it designed.
So my question was, what caused the engines to flame out? At the crash site, a new development brings hope of finding some answers.
Divers have recovered the aircraft's flight data recorder.
Let's take a look at this.
Investigators focus on the engine performance numbers.
Now, check out the fuel flow right here.
The data shows that, when the plane entered the storm, fuel consumption shot up.
But despite the higher fuel flow, engine speed remained constant.
And yet the engine rotation remains the same and does not increase.
It tells investigators that the engines were working hard battling against the heavy rainstorm.
Fuel flow would go up because of the ingested water, because it increased air density.
And then suddenly the engines died.
What changed? 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.
So let's hear what was happening inside the cockpit.
Are you plugged in? - Go ahead.
- Let's avoid that cell.
- Say, heading 300.
- At the start of the recording, the audio quality is good.
Control, Garuda 421 requesting heading 3-0-0.
Yes, sir! Number two as well.
Whoa.
Turn it down a bit.
But soon noise from the pounding storm makes it almost impossible to decipher sounds in the cockpit.
Can you isolate the voices? Investigators can no longer make out what the pilots are saying.
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.
When we listened to the CVR it's really hard to understand.
Stop.
Rewind.
Try again.
Then, in the last seconds of the recording, a non-human voice can be heard.
Terrain.
Terrain.
Terrain.
- It's saying 'terrain'.
- Terrain.
Terrain.
It's a ground proximity warning.
Investigators have stumbled across a huge clue.
Terrain.
Terrain.
Terrain.
Terrain.
- Terrain? - Terrain.
No, not terrain.
- It can't be.
- Terrain.
At 18,000 feet, the onboard computer detected something solid below the plane, something as solid as terrain.
When I heard 'terrain, terrain' I was surprised.
First, there was no terrain the area.
There's no amount of rain in the world can trigger than warning.
What was happening? 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.
Come see this for a second.
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.
- Look at these.
TRANSLATION: I'd never seen this before.
There's only one thing this could be.
Hail.
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.
Terrain.
Terrain.
The hail was estimated to be the size of tennis balls, which is enormous and detrimental to the aircraft.
Part of the engines' recent modifications had specifically to do with hail.
The engine is designed to handle 10g per meter cubed, a fairly large amount of precipitation.
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.
None of these numbers match up.
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.
That's insane.
And based on our tests we conclude that the amount of ice was more than 18g per cubic metres.
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.
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.
Engines power on.
OK.
Let's add some water and ice.
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.
Bringing it up now.
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.
I think we have our answers here why the engines died.
The engine test leaves no doubt.
That was a big ah-ha moment for them, because adding the ice to the water caused the engine to finally stop.
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 - Let's avoid that cell.
- .
.
not enough to help the crew steer clear of dangerous weather? Investigators review the satellite weather data from the day of the crash.
Let me just take a look at this radar map again.
OK.
So.
Your track took you straight into the worst part of the storm.
TRANSLATION: Why did Captain Rozaq choose such a dangerous route? The plane's weather radar should have helped them find a way around the storm.
Why would you enter the storm? Why not detour? I think we just veer a little to the left into that green gap.
We should be fine.
The pilots were under the impression that they had an opening that went all the way through the weather.
The radar showed green.
We should have been safe.
Why would your radar indicate a safe passage? I don't know.
But suddenly everything changed.
It seems the radar didn't pick up the danger ahead.
Where did this come from? The alley that they were trying to go down closed up on 'em and was not the good flight path that they were hoping for.
Investigators need to know why.
Strap in.
So this - They consult a radar expert.
- is where they entered - the storm.
- And learn that pilots can face the dangers of something called radar shadowing.
Radar shadowing is the radar's inability to identify other weather that could be in front of you that you're trying to avoid.
Radar shadow? 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.
So it would be deceiving that you were flying into some good weather and in reality you were entering into another severe storm.
The Garuda plane's dangerous flight path finally makes sense.
So what you're saying is, they sought refuge under radar shadow.
The crew didn't realise they were flying into weather severe enough to knock out their engines.
But there's still one unanswered question.
The hailstorm killed the engines Start APU.
.
.
but what killed the 737's power supply? We've lost all power.
TRANSLATION: The plane lost its electrical supply, which means there was no power left onboard at all.
We were very concerned and needed to find out why this happened.
Investigators know that Garuda Flight 421 somehow lost all electrical power If they hadn't lost power, they could have restarted the engines once they were outside the storm.
What happened? .
.
but they still don't understand how that happened.
Thanks for coming, Captain.
Please, have a seat.
Investigators hope Captain Rozaq can remember some overlooked detail.
I just have a few more questions.
Now, take us through exactly what happened after the engines flamed out.
As soon as the engines died, we followed the relight procedure.
Engine start switches to flight! - Engine start switches to flight.
- Start levers to cut-off! - Start levers to cut-off.
- They followed procedure - to the penny.
- Relight failed.
When the engines didn't relight, they tried to start the auxiliary power unit to restore electricity to the entire plane.
And then what happened? Disaster.
Start APU! Start APU.
We've lost all power.
Unfortunately, after two attempts to restart the engines and trying to start the APU, it depleted the battery.
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.
Is there anything else that you can remember? 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.
TRANSLATION: When I was interviewing Captain Rozaq, he mentioned the battery capacity was just 22 volts when he tried to revive the engines.
22 is within the limit, but it's the lowest value so it's considered to be weak.
A fully charged battery in a 737 has 24 volts.
Are you sure it's 22, not 24? 22 volts.
I remember.
Another two volts might have made the difference in getting the engines started or getting the APU started.
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.
We found the cell condition was one of the most damaged and it reduced the battery capability quite significant.
But how significant was the damage? Was the battery too weak to restart a flamed-out engine? Investigators stage a test to find out.
Let's start water and ice up to 18g per cubic metre.
They replicate the flight conditions and follow the exact procedure the pilots used trying to restart their engines.
OK.
Initiate restart engine procedure.
Engine start switches to flight! - Engine start switches to flight.
- Start levers to cut-off! Start levers to cut-off.
- Start levers to idle! - Start levers to idle.
Timing 30 seconds.
28, 29, 30.
OK.
First attempt failed.
Battery to 20 volts.
Keep precipitation ready and let's see what happens to the battery in a second attempt, alright? So we'll start timing once again.
And we're going.
Try it again! Engine start switches to flight.
- Engine start switches to flight.
- Start levers to idle! Start levers to idle.
Timing 30 seconds.
28, 29, 30.
Battery has dropped to 12 volts, making it practically useless.
- And now try to start the APU.
- Start APU.
Start APU.
- We've lost all power! - They had no chance.
The restart procedure completely drained their faulty battery.
It was not capable to support the engine restart in emergency conditions.
Finally, investigators understand all the contributing factors that knocked Flight 421 from the sky.
I think we just veer a little to the left into that green gap.
- We should be fine.
- 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.
Perform engine flameout procedure.
- Engine start switches to flight.
- Engine start switches to flight.
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 CFM56 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.
TRANSLATION: It's the biggest honour I will ever receive in my life.
Beyond the public recognition, the crew has received enduring gratitude.
TRANSLATION: He saved so many lives onboard the plane.
For that, I salute Captain Rozaq.
TRANSLATION: We felt the two of them were chosen by God to bring us to safety on the river.
They were our heroes.
Captioned by Ai-Media ai-media.
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Where did this come from? Strap in.
TRANSLATION: The shaking was so violent, I almost lost control of the plane.
Terrified passengers just want the nightmare to end.
TRANSLATION: I was scared.
Extremely scared.
Instead, the white-knuckle ride gets much worse.
Engine one flamed out! And engine two flamed out! You're in extreme dire circumstances when you have a dual - engine flameout.
- The 56-ton jet is falling from the sky.
Please forgive our sins.
Let us have the strength to save our passengers.
TRANSLATION: I felt that death was really upon us.
We were about to face our fate.
And so we prayed.
A Boeing 737 cruises high above the islands of Indonesia.
The crew of Garuda Indonesia 421 is about halfway through a short domestic flight.
TRANSLATION: We were at 28,000 feet on the way to Adisucipto Airport in Yogyakarta.
Captain Abdul Rozaq is a senior pilot with Indonesia's national airline.
How does the weather look in Yogyakarta? His first officer is Harry Gunawan.
It should be fine but there might be a bit of rain.
TRANSLATION: I had flown several times with Harry Gunawan, so it was nothing new.
We knew each other quite well.
Today, the cabin crew is responsible for 54 passengers.
Madam, can I offer you a drink? Yes.
I'll have tea, please.
Tuhu Wasono has been a Garuda flight attendant for 16 years.
TRANSLATION: Everything was normal.
We offered food and drinks for the passengers.
We checked the cabin and we chatted.
- Thank you.
- Sutji Suharjanti is a senior government official on her way to an important meeting.
TRANSLATION: Because of work I fly often and I have done so since the '70s.
I really love flying.
The flight is a 60 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.
Let's avoid that cell.
Say heading 300.
Control, Garuda 421.
Request heading 300 to avoid some weather up ahead.
Garuda 421, confirmed heading 300.
Fly direct to Bravo Alpha NDB after clearing weather.
Air traffic control authorises a slight course correction to steer the plane around some looming clouds.
TRANSLATION: 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.
But soon more large storm clouds appear in their path.
What do you think? TRANSLATION: I could see the green, yellow and red on the radar and I knew that the safest route would be towards the green.
I think we just veer a little to the left into that green gap.
We should be fine.
The weather ahead could make for a bumpy ride.
Prepare the cabin for a little turbulence.
- Hopefully it won't be too rough.
- Yes, captain.
As a precaution, the passengers are advised to fasten their seatbelts.
TRANSLATION: I never thought it was something unusual.
I've been asked to put my seatbelt on many times before.
Seatbelts.
Can I just get you to do up your seatbelt? Garuda 421.
Request clearance to descend to flight level 190.
Garuda 421, you are cleared to 190.
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.
Where did this come from? Well, we're in it now.
Strap in.
TRANSLATION: I had directed the plane towards the green, but as soon as I entered the cloud everything went red.
This was a massive super cell.
It encompassed a large amount of area that the pilots were forced to navigate in.
TRANSLATION: I was extremely surprised.
We'd already entered the cloud so, like it or not, we had to go through the storm.
The sudden turbulence is far worse than anyone in the cabin was expecting.
TRANSLATION: We started to feel the plane shaking violently and some people started to scream.
TRANSLATION: The turbulence made walking impossible.
The trays were flying around.
I was afraid I'd fall on someone.
TRANSLATION: The shaking was so violent, I almost lost control of the plane.
The engines! The captain spots a serious problem.
Yes, sir.
One and two are dropping.
They're suddenly losing engine power.
Increasing thrust! Nothing.
- Keep your eyes on them.
- Sir.
Moments later, the crisis gets even worse.
Engine one flamed out! Confirmed.
Terrain.
And engine two flamed out.
Both engines have flamed out, the combustion process extinguished.
You're in extreme dire circumstances when you have a dual engine flameout.
The plane now has no thrust at all.
Inside, they've lost primary electricity.
All systems switch to backup power.
TRANSLATION: All of a sudden the emergency lights came on.
I was shocked to see that.
Captain Rozaq struggles to keep the plane steady as the altitude starts to drop.
TRANSLATION: I immediately yelled for the emergency checklist.
Perform engine flameout procedure.
- Engine start switches to flight.
- Engine start switches to flight.
- Start levers to cut-off.
- Start levers to cut-off.
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.
Timing, 30 seconds.
The restart procedure demands patience.
TRANSLATION: We timed it for 30 seconds, as is the protocol, and waited for them to light up.
Please, God.
Just to see my family again.
Please help us, God.
Just to see my family again.
TRANSLATION: 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.
By now, the engines should have restarted.
- Relight failed.
- But both of them are still dead.
- Try it again.
- OK.
Let's go.
Engine start switches to flight.
Engine start switches to flight.
The plane is now dropping 1000 feet every 15 seconds.
- That's an extreme emergency.
- Timing, 30 seconds.
You have very little options, and immediate action is required.
Nothing.
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.
TRANSLATION: After the engines wouldn't start a second time, I knew we still had our auxiliary power unit, the APU.
The APU is a jet fuel-powered generator that provides electrical power for the aircraft.
The APU may be their only hope.
- Start APU.
- Start APU.
But as they try to start it - We've lost all power! - .
.
catastrophe strikes.
TRANSLATION: When he tried to turn on the standby generator, everything shut down.
OK.
Figure it out.
TRANSLATION: Electricity was gone.
Flight instruments, gone.
Everything went dark.
I had no tools to fly the plane.
Controllers are stunned to see flight 421 vanish from radar.
Garuda 421, do you read me? 421, please report your position.
Mayday.
Mayday.
Mayday! Garuda 421 Mayday! TRANSLATION: We were still within the severe turbulence.
We had tried everything in the book.
So my copilot grabbed the mic and yelled, "Mayday, mayday, mayday.
" Mayday, mayday, mayday.
Garuda 421.
Mayday! But controllers can't hear the desperate call.
Garuda 421, do you read me? Please report your position.
Mayday! Mayday! Mayday! Garuda 421.
They've lost all contact with the stricken plane.
TRANSLATION: I heard "Mayday, mayday.
" Then I overheard they were saying "No power, no power.
" - No power, no radio.
- TRANSLATION: That's when I realized the plane had no working engine.
Everything was off.
No power.
No radio.
- What do we have? - Emergency instruments only.
They would have the standby attitude indicator, or horizon, the standby airspeed indicator and a magnetic compass.
We're in God's hands now.
The pilots pray for help.
Please forgive our sins and let us have the strength to save our passengers.
TRANSLATION: I felt that death was really upon us.
We were about to face our fate.
And so we prayed.
TRANSLATION: 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.
The 56 ton jet with no power is falling fast.
But the pilots aren't giving up.
Let's see if we can find ourselves an airport.
The airplane would be gliding.
It would be losing altitude, but the airplane continues to fly whether the engines are running or not.
Confirm our optimal speed for drift down.
- Yes, sir.
- TRANSLATION: I actually couldn't see the standby instruments.
They were so small.
So I had to rely on my copilot.
Drift-down airspeed 212 knots.
212.
Current speed, please.
You need to lose speed.
It would be very challenging to try to land a 737 without power and without any type of assistance.
At roughly 8000 feet, Garuda flight 421 finally escapes the storm.
OK.
Let's figure out where we are.
But the captain's task still seems impossible - landing a plane with no engines and no electronic guidance.
TRANSLATION: I didn't even know where we were because my instruments were dead.
We're near the Solo River, sir.
Where's the airport? Quickly.
We've passed it, sir.
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.
We have to land somewhere.
Let's see what we've got.
TRANSLATION: 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.
Dropping lower and lower, the crew of Garuda 421 scrambles to find somewhere to land.
- The rice field, sir! - Negative.
Too risky.
Landing in the rice paddy could have cartwheeled the airplane.
It could have made the airplane break in several pieces as well.
With his plane falling fast and no other option in sight, Captain Rozaq decides to do something few pilots have ever tried.
OK.
The river then.
It's our best chance.
Yes, sir.
Tell me what to do.
No gear, no flaps.
Watch my speed.
The Solo River is narrow and twisting.
Ditching a 737 on it won't be easy.
TRANSLATION: But I believed the plane would suffer less from the impact and we'd have a better chance of surviving.
But there's another obstacle.
Bridge! - Can we go under it, sir? - No.
TRANSLATION: I wanted to pass under the bridge.
But I could make out that there were concrete pillars underneath it.
3000 feet.
Captain Rozaq makes a split-second decision.
Let's circle around and put it down over there.
- Turn with me! - Turning.
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.
A large amount of force is required without hydraulics.
It would be the equivalent of trying to drive your car without - power-steering assistance.
- Bank angle, sir.
Look! I see.
I see.
I see.
Keep turning or we don't make the river.
Turn hard! TRANSLATION: 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.
TRANSLATION: For the first time I saw a river, a bridge and rice fields.
But I was confused.
There was no runway.
Speed? 170, sir.
- That'll do.
- As they line up with the river, First Officer Gunawan notices another problem.
There's another bridge! Altitude? The bridge can't be more than 80 feet.
We're good.
TRANSLATION: It turns out I had to land the plane between two bridges.
150! - Warn the cabin.
Brace for landing.
- Brace for landing! Brace for landing! Brace for landing.
Everyone, brace for landing! OK, OK, OK.
Here we go.
50! 40! Help us, God.
30! Brace! TRANSLATION: 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.
Flight 421 hits the water at almost 200 miles an hour.
- Are you OK? - Ah.
Alive.
The cabin of flight 421 has been demolished.
TRANSLATION: When the plane finally stopped after the emergency landing, I was very relieved and grateful.
TRANSLATION: I wondered if there was blood on my feet.
It turned out it was just water.
I said, "Thank God I survived.
" TRANSLATION: I began the evacuation process.
I helped the passengers who were near me at the front of the plane.
Thank you, God.
Let's check on the passengers.
From the emergency exit, passengers can wade safely to shore.
TRANSLATION: I was the last person to leave the plane.
Of the 60 passengers and crew onboard, all but one make it out alive.
I'm very surprised there was only one fatality.
It's a sheer miracle that more people did not perish in the accident.
Despite the skilful 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? 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.
It will reveal all the information we need, all of the engine behaviour, all of the pilot communications, so we really, really need this black box.
While they wait for word on the flight recorders, investigators speak to Captain Rozaq.
- Thank you for coming, captain.
- They want to learn more about - the pilot behind this landing.
- Thank you.
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.
TRANSLATION: 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.
Captain Rozaq quickly rose through the ranks at Garuda.
TRANSLATION: I was extremely happy to join the biggest airline in Indonesia.
It was a dream come true.
So can you tell me exactly what happened? I've never experienced an engine flameout before.
I thought these engines could handle anything.
My first big question is what caused the engines to flame out simultaneously.
- Why couldn't you relight them? - We tried.
Maybe they had a fault? It didn't make sense.
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.
So there's probably 4000 to 6000 CFM56 in use at the moment.
It's a very reliable engine and has a very good history.
Let's take a look at the occurrence manual.
But as investigators learn, even the best engine isn't foolproof.
TRANSLATION: There were some cases with similar aircraft where the engine flamed out.
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.
They found that the dome shape worked better for both ice and hail.
So why did this redesigned engine now fail? See, it doesn't make any sense.
I was surprised that the dual engine flameout occurred to the engine that has been modified for precipitations.
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.
Everything seems to be good.
My opinion was that the engine, including the modification, was working as it designed.
So my question was, what caused the engines to flame out? At the crash site, a new development brings hope of finding some answers.
Divers have recovered the aircraft's flight data recorder.
Let's take a look at this.
Investigators focus on the engine performance numbers.
Now, check out the fuel flow right here.
The data shows that, when the plane entered the storm, fuel consumption shot up.
But despite the higher fuel flow, engine speed remained constant.
And yet the engine rotation remains the same and does not increase.
It tells investigators that the engines were working hard battling against the heavy rainstorm.
Fuel flow would go up because of the ingested water, because it increased air density.
And then suddenly the engines died.
What changed? 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.
So let's hear what was happening inside the cockpit.
Are you plugged in? - Go ahead.
- Let's avoid that cell.
- Say, heading 300.
- At the start of the recording, the audio quality is good.
Control, Garuda 421 requesting heading 3-0-0.
Yes, sir! Number two as well.
Whoa.
Turn it down a bit.
But soon noise from the pounding storm makes it almost impossible to decipher sounds in the cockpit.
Can you isolate the voices? Investigators can no longer make out what the pilots are saying.
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.
When we listened to the CVR it's really hard to understand.
Stop.
Rewind.
Try again.
Then, in the last seconds of the recording, a non-human voice can be heard.
Terrain.
Terrain.
Terrain.
- It's saying 'terrain'.
- Terrain.
Terrain.
It's a ground proximity warning.
Investigators have stumbled across a huge clue.
Terrain.
Terrain.
Terrain.
Terrain.
- Terrain? - Terrain.
No, not terrain.
- It can't be.
- Terrain.
At 18,000 feet, the onboard computer detected something solid below the plane, something as solid as terrain.
When I heard 'terrain, terrain' I was surprised.
First, there was no terrain the area.
There's no amount of rain in the world can trigger than warning.
What was happening? 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.
Come see this for a second.
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.
- Look at these.
TRANSLATION: I'd never seen this before.
There's only one thing this could be.
Hail.
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.
Terrain.
Terrain.
The hail was estimated to be the size of tennis balls, which is enormous and detrimental to the aircraft.
Part of the engines' recent modifications had specifically to do with hail.
The engine is designed to handle 10g per meter cubed, a fairly large amount of precipitation.
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.
None of these numbers match up.
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.
That's insane.
And based on our tests we conclude that the amount of ice was more than 18g per cubic metres.
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.
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.
Engines power on.
OK.
Let's add some water and ice.
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.
Bringing it up now.
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.
I think we have our answers here why the engines died.
The engine test leaves no doubt.
That was a big ah-ha moment for them, because adding the ice to the water caused the engine to finally stop.
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 - Let's avoid that cell.
- .
.
not enough to help the crew steer clear of dangerous weather? Investigators review the satellite weather data from the day of the crash.
Let me just take a look at this radar map again.
OK.
So.
Your track took you straight into the worst part of the storm.
TRANSLATION: Why did Captain Rozaq choose such a dangerous route? The plane's weather radar should have helped them find a way around the storm.
Why would you enter the storm? Why not detour? I think we just veer a little to the left into that green gap.
We should be fine.
The pilots were under the impression that they had an opening that went all the way through the weather.
The radar showed green.
We should have been safe.
Why would your radar indicate a safe passage? I don't know.
But suddenly everything changed.
It seems the radar didn't pick up the danger ahead.
Where did this come from? The alley that they were trying to go down closed up on 'em and was not the good flight path that they were hoping for.
Investigators need to know why.
Strap in.
So this - They consult a radar expert.
- is where they entered - the storm.
- And learn that pilots can face the dangers of something called radar shadowing.
Radar shadowing is the radar's inability to identify other weather that could be in front of you that you're trying to avoid.
Radar shadow? 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.
So it would be deceiving that you were flying into some good weather and in reality you were entering into another severe storm.
The Garuda plane's dangerous flight path finally makes sense.
So what you're saying is, they sought refuge under radar shadow.
The crew didn't realise they were flying into weather severe enough to knock out their engines.
But there's still one unanswered question.
The hailstorm killed the engines Start APU.
.
.
but what killed the 737's power supply? We've lost all power.
TRANSLATION: The plane lost its electrical supply, which means there was no power left onboard at all.
We were very concerned and needed to find out why this happened.
Investigators know that Garuda Flight 421 somehow lost all electrical power If they hadn't lost power, they could have restarted the engines once they were outside the storm.
What happened? .
.
but they still don't understand how that happened.
Thanks for coming, Captain.
Please, have a seat.
Investigators hope Captain Rozaq can remember some overlooked detail.
I just have a few more questions.
Now, take us through exactly what happened after the engines flamed out.
As soon as the engines died, we followed the relight procedure.
Engine start switches to flight! - Engine start switches to flight.
- Start levers to cut-off! - Start levers to cut-off.
- They followed procedure - to the penny.
- Relight failed.
When the engines didn't relight, they tried to start the auxiliary power unit to restore electricity to the entire plane.
And then what happened? Disaster.
Start APU! Start APU.
We've lost all power.
Unfortunately, after two attempts to restart the engines and trying to start the APU, it depleted the battery.
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.
Is there anything else that you can remember? 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.
TRANSLATION: When I was interviewing Captain Rozaq, he mentioned the battery capacity was just 22 volts when he tried to revive the engines.
22 is within the limit, but it's the lowest value so it's considered to be weak.
A fully charged battery in a 737 has 24 volts.
Are you sure it's 22, not 24? 22 volts.
I remember.
Another two volts might have made the difference in getting the engines started or getting the APU started.
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.
We found the cell condition was one of the most damaged and it reduced the battery capability quite significant.
But how significant was the damage? Was the battery too weak to restart a flamed-out engine? Investigators stage a test to find out.
Let's start water and ice up to 18g per cubic metre.
They replicate the flight conditions and follow the exact procedure the pilots used trying to restart their engines.
OK.
Initiate restart engine procedure.
Engine start switches to flight! - Engine start switches to flight.
- Start levers to cut-off! Start levers to cut-off.
- Start levers to idle! - Start levers to idle.
Timing 30 seconds.
28, 29, 30.
OK.
First attempt failed.
Battery to 20 volts.
Keep precipitation ready and let's see what happens to the battery in a second attempt, alright? So we'll start timing once again.
And we're going.
Try it again! Engine start switches to flight.
- Engine start switches to flight.
- Start levers to idle! Start levers to idle.
Timing 30 seconds.
28, 29, 30.
Battery has dropped to 12 volts, making it practically useless.
- And now try to start the APU.
- Start APU.
Start APU.
- We've lost all power! - They had no chance.
The restart procedure completely drained their faulty battery.
It was not capable to support the engine restart in emergency conditions.
Finally, investigators understand all the contributing factors that knocked Flight 421 from the sky.
I think we just veer a little to the left into that green gap.
- We should be fine.
- 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.
Perform engine flameout procedure.
- Engine start switches to flight.
- Engine start switches to flight.
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 CFM56 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.
TRANSLATION: It's the biggest honour I will ever receive in my life.
Beyond the public recognition, the crew has received enduring gratitude.
TRANSLATION: He saved so many lives onboard the plane.
For that, I salute Captain Rozaq.
TRANSLATION: We felt the two of them were chosen by God to bring us to safety on the river.
They were our heroes.
Captioned by Ai-Media ai-media.
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