Original subtitles

Narrator: Cruising in clear skies

35,000 feet above the Indonesian jungle,

a 737 suddenly plummets from the sky.

Man: The debris is at the bottom of the river.

Man: Good lord. take a look at this.

Narrator: Evidence points to a serious mechanical failure--

one that could ground commercial flights across the globe.

Man: Because of the history of the 737, we were concerned.

Narrator: But when the full story behind the crash

of Silk Air flight 185 is finally revealed...

Man: It's 2.5 units.

Narrator: The cause is more disturbing

than anyone could have imagined.

Man: It was kind of shocking.

Man: I didn't really know what to believe.

Pilot: Mayday, Mayday!

Flight attendant: We'll be serving lunch shortly.

Tsu Way Ming: Good afternoon, ladies and gentlemen,

this is your captain.

My name is Tsu Way Ming.

On the flight deck this afternoon with me

is First Officer Duncan Ward.

We'd like to welcome you aboard,

and we are now climbing through 19,000 feet.

Narrator: Silk Air flight 185

is climbing to its cruising altitude.

The Boeing 737 is carrying 97 passengers and 7 crew

from Jakarta, Indonesia,

to the airline's home base, Singapore.

The flight should take about 80 minutes

heading North over the rainforests of Sumatra

to Singapore's Changi international airport.

Ming: We'll be cruising today at 35,000 feet.

Peter Macmillan: Tsu Way Ming was an experienced

Singapore air force pilot.

He'd been in their aerobatic team.

He was always listed as an above average pilot.

Narrator: Today's First Officer is 23-year-old Duncan Ward.

The new Zealand-born pilot has been flying with Silk Air

for a little more than a year.

Derek Ward: Duncan initially found flying

at the age of about 14.

Suddenly he had a purpose in life.

I think that's the best way to describe it.

Macmillan: He came from another operator

already top rated on the Boeing 737,

and when I conducted his induction training for Silk Air

I recognized that he was

a well above average pilot as well,

despite his young age.

Ming: I'll get back to you

just before our descent into Singapore

with an updated weather forecast.

Thank you.

Narrator: The twin-engine jet is the neWest addition

to the Silk Air fleet.

A Boeing 737-300 series, it went into service just 9 months ago.

Macmillan: At the time the 737 was probably

the most widely used jet transport in the world.

Ward: Duncan reckoned that he was

the luckiest guy in the world

because whereas some people

might go the office in a Ferrari,

he went to the office in a 737, so he loved it.

Duncan Ward: Silk air 185 maintaining 3-5-0.

Controller: Silk air 185 maintain 3-5-0

cleared direct to Pardi.

Duncan Ward: Wilco Silk Air 1-8-5.

Ward: The flight to Jakarta and back was a standard route.

Everything was absolutely normal, absolutely routine.

Narrator: On flights as smooth as this one,

it's common for pilots to get up and stretch their legs.

Ming: I'm going back for a while.

Finish your lunch.

Ward: I am.

Ming: Some water?

Narrator: 30 minutes after takeoff

Jakarta air traffic control

makes its last scheduled radio call to flight 185.

Controller: Silk Air 1-8-5 maintain 3-5-0.

At Pardi contact Singapore 1-3-4.4.

Ward: Silk Air 1-8-5 roger. 134.4 before Pardi.

Narrator: The crew is reminded to check in next

with Singapore air traffic control.

Macmillan: Singapore air traffic control

did not expect to hear from the aircraft

for another five to six minutes

so it was in a virtual no man's land

as far as communications are concerned.

Narrator: Moments later, while still cruising at 35,000 feet,

the plane banks sharply and begins to dive.

Macmillan: The cabin crew were probably serving lunch

at the time, with carts in the aisles.

It would have been horrific.

The aircraft would have been inverted.

Anything unsecured would have ended up on the ceiling.

Ward: What happens to all of the people

who might be standing up?

to the people who are not buckled in?

it doesn't bear careful examination.

It's too horrible.

Narrator: At Jakarta air traffic control,

Silk Air 185 has vanished from radar.

The controller has heard no Mayday call.

He tries to get a message to the missing flight

with the help of another pilot.

Controller: Indonesia 2-3-8 Jakarta.

Pilot: Go ahead. Indonesia 2-3-8.

Controller: Please relate to Silk Air 1-8-5

to contact Singapore 1-3-4.4.

Pilot: Roger. indonesia 2-3-8.

Narrator: But the 737 is already submerged

beneath the murky waters of Indonesia's Musi river,

halfway between Jakarta and Singapore.

Local villagers report the crash.

Santoso Sayogo: And they're telling stories

about the aircraft coming very fast from an altitude.

Narrator: Along the river, people search for survivors

but find only small bits of debris.

A 50-ton aircraft carrying 104 people

has all but disappeared.

News of the Silk Air crash is met with shock in Singapore,

home to almost half the passengers.

There is very little hope that anyone has survived.

24 hours later,

following the crash of Silk Air 185,

Indonesian Investigator Santoso Sayogo

takes charge of the team

from the National Transportation Safety Committee.

Sayogo: Empty those bags.

Put it with the other bags for processing.

Sayogo: What we did is to go to the crash site,

observe, and then record

and preserve anything that we can use

for the later investigation.

More small debris.

Narrator: The scale of the disaster soon becomes evident.

There are no survivors.

All 104 passengers and crew have been killed,

including veteran pilot Captain Tsu Way Ming

and his First Officer, Duncan Ward.

Ward: It was just complete bewilderment

as to how it might have happened.

In that situation you go into a complete state of shock.

I didn't really know what to believe.

Narrator: The NTSC calls in Navy divers and support ships

to help with the recovery effort.

Sayogo: The debris is at the bottom of the river.

If I can describe it, it's murky water, mud and clay.

Most of the debris was in the clay.

Narrator: At the Silk Air crash site

there are no bodies to mourn over.

Searchers have found hardly any human remains at all.

Ward: It was just something that as a father was so horrendous

that it just has an enormous psychological effect on you.

Narrator: The 737 is the most popular commercial airliner

in the world.

Five new 300-series jets

roll off the Boeing assembly line every month.

Having one fall from the sky on a calm, clear day

without any indication of trouble

sends a chill through the entire industry.

Investigators are under intense pressure

to figure out what went wrong.

Following the crash of Silk Air 185,

Indonesian Investigator Santoso Sayogo

faces the biggest challenge of his career.

Fortunately, he won't have to face it alone.

Because the 737 is American-made,

U.S. Air accident Investigator Greg Feith

joins the investigation.

Sayogo: Mr. Feith.

Narrator: He's one of the NTSB's top investigators...

Feith: Santoso.

Narrator: With more than 17 years of experience.

Sayogo: And thanks for coming so soon.

Feith: I'm glad to help.

I know you guys are stretched pretty thin.

Greg Feith: Initially when we were working

with the Indonesians,

they had never done any kind of wreckage recovery

like this before.

We in the states had had a lot of experience

with a variety of different accidents.

Narrator: Investigators initially suspect

some catastrophic mechanical failure

but don't know which part could be to blame.

Sayogo: Tough to get the debris pattern.

It's all under water.

Narrator: Without knowing how the wreckage is distributed,

it's hard to know where to start.

Sayogo: We need the recorders.

Feith: One of our primary concerns

was trying to get the flight data recorder

and the cockpit voice recorder

because that was really going to help

in establishing the course of the investigation--

what directions, what elements

that we really needed to focus our energies on.

Controller: Silk Air 1-8-5 maintain 3-5-0.

At Pardi contact Singapore 1-3-4.4.

Ward: Silk Air 1-8-5, roger 134.4.

Narrator: the plane's black boxes,

the electronic recording devices,

capture every sound in the cockpit

and provide a detailed picture of how the plane was flying.

Feith: And the CVR and the FDR

will record all the way till impact.

Narrator: Without them, the investigation is crippled.

But for the divers on the musi river,

the search is proving difficult.

Feith: The visibility in the water

was basically six inches in front of your face.

They had to swim down and feel on the bottom in the mud

what they thought were pieces,

grab them and bring them to the surface.

We didn't know if we were going to get the CVR and/or the FDR.

Narrator: If the black boxes are embedded deep in the mud,

they may be beyond reach.

Silk Air flight trainer Peter Macmillan joins the team.

He has knowledge of the airline

and personal experience working with both pilots.

Macmillan: I was basically sent there as a conduit

between the investigation and Silk Air

to explain any Silk Air procedures to investigators.

Narrator: To understand flight 185's sudden dive

he studies indonesian radar returns

that show the plane's flight path.

Macmillan: the aircraft's transponder

identifies it on the radar screens.

And it could also show the height of the aircraft

and it could actually, with some calculation,

determine the speed of the aircraft.

Narrator: Macmillan calculates that the flight time

from takeoff to the last recorded radar return

was just under 36 minutes.

Macmillan: Good lord. take a look at this.

Narrator: The first 35 minutes are completely normal.

But the last 30 seconds of the radar plot

paint a terrifying picture.

Macmillan: The aircraft disappeared from radar returns

when it went below 20,000 feet.

But when the aircraft left 35,000 feet

to below 20,000 feet,

it gave an approximate rate of descent

of over 30,000 feet per minute.

The maximum rate of descent is normally in the order

of 5, 6, 7,000 feet per minute.

So this was a descent of great magnitude.

Narrator: Investigators determined

that in the seconds before impact,

the plane was traveling faster than the speed of sound.

Investigators are desperate to recover the black boxes.

They intensify the musi river salvage effort.

Feith: We brought in heavy assets

which was this ocean-sized dredge, 20, 25-foot bucket

that was able to scoop very large mounds of mud

out of the musi river.

Narrator: But the river is vast--almost a mile wide.

Even with the dredger,

the black boxes May never be found.

Sayogo: They could be anywhere.

Sayogo here.

Man: Boss, I think we found something important,

but it's not in the river, it's on land.

Sayogo: On land? where?

Man: About four kilometers East of the river.

Sayogo: We've got debris, East of the river.

Narrator: They May have their first solid lead.

Feith: Witnesses said that they saw parts

or things fluttering down that landed in the jungle.

Narrator: Aircraft debris litters a site

in the Sumatran rainforest

just East of where flight 185 hit the Musi river.

Feith: This is part of the horizontal stabilizer.

Sayogo: Be sure to get the GPS coordinates.

Feith: We did in fact find

that the horizontal stabilizers of the airplane--

the two small stabilizers on the back--

had come off in flight.

Narrator: The fragments are from control surfaces

on the plane's tail section.

Narrator: Small elevators on the very back edge of the tail

help pitch the plane up and down.

Sayogo: We're 4.5 kilometers East of the main crash site.

Feith: Right.

Narrator: The distance tells them that these fragments

were among the first To break off: A key finding.

If parts of the tail broke away at cruising altitude,

that might explain the sudden dive.

What's more, it May point to a larger problem.

Feith: Because of the history of the 737

we were concerned about the horizontal stabilizers

having separated from the rest of the aircraft in flight.

Narrator: Though the 737 is generally regarded

as a safe airplane,

it has a disturbing chapter in its history--

a dangerous malfunction known as rudder hard over.

Sayogo: Rudder hard over means that the rudder

kicks to the one side of the aircraft,

so the aircraft will have an unusual attitude.

Feith: The rudder would actually move all by itself

without being commanded by the captain or the First Officer

through the rudder pedals.

Narrator: In 1991, nearly seven years before the Silk Air crash,

a United Airlines 737 on approach to Colorado Springs

took a sudden roll to the right.

It hit the ground seconds later, killing everyone on board.

Three years later it happened again.

132 people died when a U.S. Air 737 crashed near Pittsburgh.

Both accidents were caused

by the same type of rudder malfunction.

Feith: That was a big concern because all of the sudden now

you have the airplane doing things

that the crew isn't anticipating.

Sayogo: Okay. Wrap it up.

Narrator: Investigators fear

that the deadly rudder phenomenon

May have struck again.

Feith: If the rudder had failed and it had gone hard over,

as we had seen in these other events,

that would have exposed it to higher aerodynamic loads,

and it would have separated from the aircraft.

Narrator: Even more disturbing,

the rudder problem was supposed to have been solved.

Boeing engineers came up with a fix

before construction even began

on the 737 that crashed in Indonesia.

Sayogo: For the accident aircraft

Boeing already modified the rudder.

Feith: So the question is: why would this airplane

have had an experience like that

given the fact that it had the modifications to the rudder?

Narrator: It is now crucial that the team figure out

exactly when flight 185's tail section broke off.

Did it detach at 35,000 feet, throwing the plane into a dive?

or did something else cause the rapid descent,

causing the tail to break off on the way down?

Feith: We had to examine the wreckage,

see how these stabilizers came off

and then put that story line together.

Narrator: On day five of the investigation

there's a major breakthrough.

Divers have found a key piece of the investigative puzzle

in the mud at the bottom of the musi river.

Sayogo: The accident happened on the 19 December,

and we discovered the flight data recorder

in the afternoon of the 24th, one day before Christmas.

I can confirm. it is the FDR.

Slightly damaged, but it doesn't look too bad.

Macmillan: It was kept in clean water

just to preserve the information on it,

so it would not deteriorate.

Narrator: If the FDR recording has survived,

investigators should soon know

exactly when flight 185's tail section began to break off.

Sayogo: It's up to the guys in Washington now.

Feith: We sent the flight data recorder to our laboratories

at the national transportation safety board

because the Indonesian's didn't have a lab facility like that.

Narrator: Meanwhile salvage teams continue to sift

through tons of mud pulled from the river,

in the hope that the second black box will soon turn up.

At the hangar, the search is on

for another missing piece of the plane.

Feith: I need you to find the power control unit.

It's called a PCU.

I got a photo of one here.

Ah, that's what we're looking for.

Narrator: The power control unit, or PCU, is the component

proven to have caused rudder failure

in previous 737 crashes.

Feith: One of the problems

with the power control unit on the 737

was that through contamination or environmental conditions

you could bind up parts of the component.

Narrator: No one knows if the critical component

has been found.

If it has, the PCU could give investigators

a very important clue.

It's been 20 days since Flight 185 disappeared

into the Musi river.

The dredging operation is being wound down.

Sayogo: There is nothing more they can collect

from the crash site,

so they decided to stop the dredging operation.

Narrator: Hope of finding the second black box

is all but gone.

But at the hangar in Palembang...

Feith: That's what we're looking for. Thank you.

Narrator: Long hours spent combing through aircraft debris

has finally paid off.

Feith: Can you wheel that air compressor over here?

Narrator: Greg Feith can finally examine

Flight 185's power control unit,

the critical component responsible

for the previous rudder malfunctions.

Sayogo: If they had the rudder hard over,

the opening up of the rudder PCU will indicate

that they have experienced the rudder hard over.

Narrator: Feith checks for any sign

of contamination or corrosion.

Feith: The actuation looks good.

Sayogo: There was no corrosion inside the rudder PCU.

Feith: This thing worked fine.

Macmillan: When the rudder PCU was recovered,

it was examined by engineers and investigators

and found to be perfectly serviceable.

Narrator: Rudder failure did not bring down Silk Air flight 185.

Investigators conclude that the tail debris found on land

was ripped away during the plane's supersonic plunge.

Feith: Those stabilizers separated

from the rest of the airplane at around 10 to 12,000 feet.

The aerodynamic forces

basically took those flight control surfaces

off the airplane.

But that didn't answer what prompted it.

Narrator: The pilots themselves may have left clues

about what went wrong at 35,000 feet.

But unless the missing cockpit voice recorder turns up soon,

those clues will be gone for good.

Sayogo: We are not very optimistic

because of the situation at that time.

Man on radio: Santoso, are you there?

Sayogo: Anything to report?

Man, garbled: the recorder's been found.

Sayogo: Say again.

Man: Recorder found.

Macmillan: The CVR was found on the last day of dredging,

and it was found under 27 feet of mud

under the bottom of the musi river.

It was very fortunate.

Narrator: The second recorder appears to be in good shape.

Macmillan: The CVR was then handed over to Santoso Sayogo,

and he and I then accompanied it to the NTSB in Washington.

Feith: We had to get them back to the United States

to be read out,

and we were just hoping that they were in a condition

where they were going to give us what we needed.

Narrator: With the second black box

on its way to Washington,

investigators may finally have the evidence they need

to solve the mystery of Silk Air 185.

Three weeks into the investigation,

Santoso Sayogo travels to the NTSB headquarters

to deliver the Silk Air CVR.

Sayogo: When I arrived in Washington,

the flight data recorder had already been read out.

Narrator: A printout of flight 185's flight data recorder

shows airspeed, altitude, direction

and dozens of other parameters.

But there's a problem.

Sayogo: What happened here?

they told me that the flight data recorder

was stopped in the air.

Narrator: For the first 34 minutes and 14 seconds,

all the flight parameters are normal.

Then, suddenly, nothing.

No data at all.

Sayogo: They were at cruising altitude with autopilot on.

Macmillan: The FDR ceased recording

approximately one minute before the aircraft

commenced its final descent.

Narrator: Investigators are baffled.

Why would the flight data recorder

on a newly built 737 suddenly stop

during a routine flight in clear, calm weather?

and why, just moments later, did the plane plummet to earth?

The mystery only grows deeper...

Macmillan: Ready when you are.

Narrator: When the team looks for answers

on the cockpit voice recorder.

Ming: Good afternoon, ladies and gentlemen.

This is your captain.

My name is Tsu Way Ming.

On the flight deck this afternoon with me

is First Officer Duncan Ward.

We'd like to welcome you aboard, and we are now climbing to...

Macmillan: It was just a normal flight.

The crew were communicating as they normally do,

and with the cabin crew.

There appeared to be nothing untoward at all.

Ming: I'm going back for a while.

Finish your lunch.

Duncan Ward: I am.

Feith: The crew never expressed any problem with the aircraft.

It was normal communications as best we could tell.

Ming: Some water?

Macmillan: The last noise that we heard on the CVR recording

was the snap of Tsu's shoulder harness hit the floor.

Sayogo: After that, the cockpit voice recorder stopped.

That's it?

Narrator: Just like the FDR, the CVR stops abruptly,

but not at the same time.

The cockpit voice recorder went dead six minutes sooner.

Sayogo: That's almost impossible.

Macmillan: The flight data recorders

and the cockpit voice recorders

are extremely reliable instruments,

power failures happening very rarely.

Narrator: On the 737 both recorders are located

in the rear of the plane.

They both draw power from the main electrical system.

Feith: There was nothing to suggest

that they should have stopped recording

until the airplane went into the water.

So the question was: why did they stop?

did something happen in the air to the electrical system

that caused the power to shut off?

Sayogo: There must be an explanation.

Maybe a short circuit.

Find out what you can.

Narrator: in a maintenance hangar,

technicians aboard a 737

run tests on the plane's cockpit voice recorder.

Technician: Okay. Ready?

One. Two. Three. Overload.

reset it, please.

Narrator: They overload the recorder's electrical circuit

to see what it takes to get the breaker to pop.

Technician: Let's run it again.

One. Two. Three. Overload.

Narrator: During the test they discover that it's possible

to overload the circuit and trigger the breaker.

But they discover something else.

When a power surge causes the circuit breaker to pop,

it makes quite a loud sound.

Sayogo: We can clearly hear the signature voice

of the circuit breaker pop out.

Narrator: When the test recordings are played back...

Technician: One. Two. Three. Overload.

Narrator: They discover that the CVR keeps recording

for a split second after power cuts out.

Technician: One. Two. Three. Overload.

Narrator: Just long enough to capture the sound

of its own circuit breaker popping.

Sayogo: The cockpit microphone definitely picked up the sound.

Narrator: The small noise has big implications.

Sayogo: Now let's hear the end of the flight 185 recording.

Ming: I'm going back for a while.

Finish your lunch.

Ward: I am.

Ming: Some water?

Sayogo: Again, please.

Ming: I'm going back for a while.

Finish your lunch.

Ward: I am.

Ming: Some water?

Narrator: Reviewing the final seconds

of the Silk Air recording,

they hear no last second snapping sound.

Sayogo: I don't hear it.

On the cockpit voice recorder, we don't hear anything at all.

Feith: That told us that the electronic device

did not fail from an overload where you get a surge in power

that could have popped the circuit breaker.

Narrator: Two recorders on two separate circuits

failed within minutes of each other,

and there's no evidence of any electrical fault.

Pulling the breaker by hand makes almost not sound at all.

It leads investigators to an unsettling conclusion.

Macmillan: The only remaining possibility

is that it was manually tripped.

Narrator: Someone in the cockpit

disabled the recorders on purpose.

Feith: We couldn't find any physical evidence

as to why those boxes would have failed

from a component standpoint.

Sayogo: You know what this means?

Feith: I do.

I don't like it, but I do.

Feith: It didn't pop because of an overload or a surge,

but in fact somebody

would have manually manipulated the circuit breaker

to shut down each of the boxes from recording.

Narrator: It's against the laws of commercial aviation

to tamper with the flight recorders.

Investigators have a disturbing theory

about why the recorders were disabled.

They use a Boeing flight simulator to prove it.

Sayogo: Okay. Let's input Silk Air flight 185.

Feith: We took the data that we were able to get

from the radar information

and we fed it into this motion simulator

to try and understand better the flight path of the airplane

during its spiraling descent into the Musi river.

Narrator: They fly a simulation to see what could cause a 737

to quickly drop from 35,000 feet to just below 20,000,

Silk Air's last radar return.

Sayogo: Trigger yaw damper failure, please.

Narrator: They simulate a sudden mechanical failure

and watch to see if the flight

will follow the deadly path of flight 185.

Sayogo: Not even close.

Narrator: They test more than 20 different scenarios.

Macmillan: They completed exercises

with simulated rudder hard overs and yaw damper failures

and various failures of other systems,

but under each of those conditions

there were unable to meet the parameters as recorded on radar.

Narrator: They find there's only one way to make a 737 drop

as steeply and quickly as Silk Air 185.

Sayogo: This time no failure.

Sustain pilot input only.

The only plausible trajectory that can match

is by using pilot control.

Narrator: It takes an extraordinary effort,

but by rolling the plane sharply to the right

and accelerating to top speed,

the test pilot can match the Silk Air profile.

Feith: The only way that this airplane

could maintain a nose-down attitude

and a high speed dive

was if somebody had flown it into that position.

Narrator: An air disaster that took the lives of 104 people

is beginning to look like a deliberate act,

by a skilled pilot.

Feith: That changed the complexion of the investigation.

Narrator: Before they can make a final judgment

on the cause of the crash,

investigators need physical proof.

They find it in the plane's tail section.

The salvage operation has retrieved almost 75% of the 737,

including a key part from the tail

that could confirm if flight 185

was in a commanded dive before it hit the water.

Feith: One of the telltale pieces of evidence that we found

was the trim jackscrew for the horizontal stabilizer.

Narrator: The jackscrew is a threaded rod

connected to the horizontal stabilizer.

It rotates when pilots press a trim switch

on their control column.

As it turns, it moves the stabilizer up or down,

Changing the pitch of the aircraft.

Narrator: Feith calculates the final pitch angle

on the stabilizer

based on the jackscrew's last setting.

Feith: It's 2.5 units.

It was moved deliberately to nose down from level flight.

What we found was that the trim was full nose-down trim.

Macmillan: The stabilizer trim would have been

in the cruise position.

There was really no reason for it to move forward.

Narrator: It confirms that while cruising at 35,000 feet

one of the pilots initiated the plane's dive

by moving the stabilizer down.

The Silk Air disaster has taken on a chilling new dimension.

Evan Byrne is a psychologist and human performance investigator

for the NTSB.

Evan Byrne: it was becoming clear

that the flight crew's performance

could not be ruled out

as a potential cause of the accident.

Narrator: One of the two pilots

likely crashed the plane on purpose,

killing everyone onboard.

Byrne: Throughout our investigation

we were looking at both pilots--

their professional background, their personal background,

what activities they were performing

in the days before the accident.

Ward: They looked at everything.

They examined everything in great detail.

I had great confidence in the NTSB.

I had great confidence

in the technical investigators themselves.

Ming: I'm going back for a while.

Finish your lunch.

Ward: I am.

Ming: Some water?

Narrator: The last conversation on the CVR indicates

that First Officer Ward was alone

shortly before the plane went into a dive.

Controller: Silk Air 1-8-5.

Narrator: Five minutes later Ward was still on headset.

Ward: Silk air 1-8-5. roger 134.4.

Narrator: And two minutes after that...

The plane fell into a dive.

The key question: Who was at the controls?

Byrne: Tell me a bit about Duncan.

Ward: The questions related to every aspect

of Duncan's state of mind and psychology,

also trying to establish whether or not he had

any possible motive for trying to sabotage the aircraft.

Byrne: Did he seem at all depressed in recent weeks?

Narrator: Byrne finds that Duncan Ward

got on well with colleagues.

He had no debts and no history of depression.

Byrne: His coworkers, pilots that he flew with,

were all highly positive about his performance

and skills in the cockpit.

Narrator: He learns that Tsu Way Ming

was a married father of three school-age boys.

Ming: Good afternoon, ladies and gentlemen.

This is your captain.

Narrator: At Silk Air the former air force top gun

was on the fast track.

But as they learn from a former colleague,

Ming's record was not spotless.

Byrne: What was Ming like to fly with?

he was known as a pilot who liked to push the envelope

as far as increasing speed

to try to complete flights faster than others.

Macmillan: I did hear reports from other pilots

that he did try to cut corners at times

by cutting sector times, cruising at increased speed.

Narrator: Investigators learn

that 6 months before the Silk Air disaster,

Ming had made a fast, swerving landing.

He flew in so fast that it made passengers sick.

Ming: I disagree. the landing was fine.

Narrator: The airline took disciplinary action.

Macmillan: When the company investigated,

Tsu Way Ming was demoted from a line instructor pilot

to an ordinary line captain.

Narrator: Investigators dig deeper.

Byrne: And we learned that the captain

was under significant financial stress

about the time of the accident.

Narrator: The trouble stemmed

from high risk online securities trading.

Over the last four years

Ming had lost more than a million dollars.

Byrne: Shortly before the accident,

for the second time in 1997,

Captain Tsu's trading privileges in the Singapore stock market

were suspended because of debts that he'd accumulated.

Narrator: They learn that on the morning of the flight

Tsu Way Ming had promised to repay the debt

as soon as he got back to Singapore.

But the date of the crash was important

for another reason as well.

Byrne: The Silk Air accident

occurred on the 19th of December,

which was also a significant date

in Captain Tsu's Air Force career.

Narrator: 18 years earlier to the day,

on December 19, 1979,

Tsu Way Ming took off on an Air Force training mission

with three other fighter pilots.

Feith: But he had to turn back during the course of that flight

because of a mechanical problem with his airplane.

Yet his compatriots kept on going.

Narrator: Ming's squadron mates were all killed on that mission

when their fighters slammed into a cloud-covered mountain.

Byrne: At least two of the pilots onboard

would have been very close friends to Captain Tsu.

Narrator: One of two Silk Air pilots

committed a brutal, callous act.

Byrne: It's safe to say that Ward is not our guy.

Narrator: Though the evidence is circumstantial,

investigators are convinced.

Tsu Way Ming is the one responsible

for the murder of 97 passengers and 7 crew.

But how exactly did he manage to carry out

such a horrendous crime?

No one can know for certain what happened aboard flight 185,

but investigators have a likely scenario.

Ward: Silk Air 1-8-5 maintaining 3-5-0.

Narrator: It has been six months since Tsu Way Ming

was demoted by the airline.

Macmillan: Such a demotion to an up-and-coming Singapore pilot

would be a major blow to his morale.

Controller: Silk Air 1-8-5 maintain 3-5-0.

Cleared direct to Pardi.

Narrator: The 1997 Asian Financial Crisis

has thrown the region's economies into turmoil.

The Singapore stock market has taken a beating.

Traders like Ming are hurting.

Byrne: The stresses in Captain Tsu's financial background

may have served as a distraction.

It may have affected his performance

in other ways as well.

Narrator: Piloting a jet on the anniversary

of the day he cheated death 18 years ago,

Ming makes a fateful decision.

Ming: I'm going back for a while.

Finish your lunch.

Ward: I am.

Ming: Some water?

Ward: If he was going back,

his right hand would have probably been within inches

of the cockpit voice recorder circuit breaker.

Macmillan: It's not difficult to pull one of those

leaving the cockpit without the other pilot being aware of it.

Controller: Silk Air 1-8-5 at Pardi contact Singapore 134.4.

Ward: Silk Air 1-8-5. roger 134.4.

Narrator: Ming waits until after the last radio call

before returning to the cockpit.

Ming: Duncan, there's a problem in the galley.

Macmillan: He could easily have said to Duncan Ward:

The girls want to see you in the back.

There might be a leaky tap or something like that.

Ward: All the person remaining in the cockpit has to do

is to lock the door.

Macmillan: If the circuit breaker

to the flight data recorder is pulled,

it illuminates a master caution.

There's one in front of each pilot.

So that's why he really couldn't do that

while there was another pilot in the cockpit.

Feith: The cockpit voice recorder

was no longer recording.

The flight data recorder was no longer recording.

Narrator: Ming wants no record of what he's about to do next.

Ward: The flight profile is one that Tsu Way Ming

would have been quite familiar with

because he'd been in the Singapore Air Force.

Narrator: Less than a minute after disabling the FDR,

Ming puts the 737 into a hard right roll.

Macmillan: He places it in an inverted dive

approximately 80 degrees nose-down,

and he had to use considerable force on the control column

to keep it there.

Narrator: Duncan Ward now has no hope of saving the plane.

Ward: I know that he would have done whatever he could.

Narrator: It's all over in less than a minute.

Three years after the Silk Air disaster,

Indonesia's National Transportation Safety Committee

releases a report that comes to a surprising conclusion.

Sayogo: We submit to the chairman,

but the chairman seems doesn't like what we submitted.

Narrator: The chairman of Indonesia's NTSC

overrules his investigators,

declaring in the report that the crash cannot be explained.

He argues that the cause can't be known

because the final seconds of the flight were not recorded.

Feith: It was kind of shocking.

Ward: This was a political cover-up.

I think there's no other word for it.

Narrator: In an unprecedented move,

the NTSB publicly contradicts the Indonesian report.

Feith: I authored, on behalf of the NTSB,

a very long document explaining that this was

an intentional act, not an accident.

Macmillan: I don't think any sane investigator

would find any other cause for the crash.

Narrator: Air Accident Investigators

can only offer conclusions based on the evidence they have.

The Silk Air disaster is a reminder

that sometimes evidence can point different people

in different directions.

Ward: If you wish to do

somebody a great harm,

you couldn't do much more than

to kill one of their children

and then try and cover up

that fact and lie about it.

I know that Duncan would have

wanted the truth to come out.