Original subtitles

Narrator: On approach to a remote town

in Indonesia's Papua province...

First Officer: Gear down.

Narrator:...a turboprop plane vanishes.

Controller: Trigana 267, Oksibil.

Do you copy?

[Man, Translated] We tried to think positively

that there's a chance the aircraft ended up landing

at a different airport with limited communication.

News Anchor: Overseas a search is underway

for an Indonesian plane carrying more than 50 people.

Narrator: A treacherous climb up a steep mountain

leads to the worst possible news.

Investigator: We've reached the crash site.

No survivors.

Man: The number one priority is to find the black boxes.

Narrator: With no clues, investigators hope

the damaged black boxes will solve this puzzling case.

Man: Can you turn that up?

[Humming]

That's it?

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!

♪

[Tires Screech]

♪

♪

Narrator: Sentani airport in Papua province, Indonesia.

Trigana air service pilots

Captain Hasanuddin and first officer Aryadin

are on a short layover before their fifth flight of the day.

Hasanuddin: What have we got? Like 20 minutes?

Aryadin: About that, yeah.

Hasanuddin: I think I'll get up and stretch my legs.

Want anything from the terminal?

Aryadin: I'm okay, thanks.

Hasanuddin: Okay.

Narrator: The pilots have already flown

four short flights today.

This leg will take them back to a remote airport

in the Oksibil area.

Todd Curtis: Typically, the flights of a commuter aircraft

will be an hour or less.

So the typical duty day for a pilot

might include four or more takeoffs and landings.

It's challenging in the sense of taking off and landing

are the most risky parts of any aircraft flight,

and doing so several times in a day

could put different kinds of stresses on a pilot.

Dita Amelia Kurniawan: Hello.

Narrator: Flight attendant Dita Amelia Kurniawan...

Kurniawan: Good afternoon.

Narrator:...has been with Trigana Air Service

for three years

and knows many of the regulars who fly this route.

Kurniawan: Good to see you again.

Narrator: 49 passengers will be making the short trip

to Oksibil.

Gerry Soejatman: Oksibil is a very remote area,

so most of the passengers would be local government officials,

local businessmen.

Very few tourists go to Oksibil.

♪

Hasanuddin: Do you want to switch on the way back?

Aryadin: No, I'm good for one more leg.

[Phone Rings]

Hasanuddin: All set back there, Dita?

Kurniawan: Good to go.

Hasanuddin: Thank you, Dita.

[Engines Revving]

Narrator: At 2:22 pm, Flight 267 takes off.

Aryadin: Landing gear up.

Hasanuddin: Landing gear is up.

Aryadin: Flaps set to zero.

Hasanuddin: Flaps zero.

Narrator: The flight to Oksibil takes 40 minutes.

The estimated arrival time is 3:04 pm.

Hasanuddin: We're at 2,000 feet. Want to turn on the autopilot?

Aryadin: Autopilot engaged.

Narrator: The pilots are flying an ATR 42-300,

a twin-turboprop short-haul aircraft.

Curtis: The ATR 42 is

a medium capacity commuter-type aircraft.

They're popular because they can get into smaller airports,

places where you can't really get an airplane

that's a 737 or 747 size into and out of the airport.

Narrator: Minutes later, the plane reaches

its cruising altitude of 11,500 feet.

[Ding]

Kurniawan: Water?

Narrator: The flight is so short...

Hasanuddin: I'll call Oksibil.

Narrator:...the captain is already preparing

for the descent into Oksibil.

Hasanuddin: Oksibil, Trigana 267.

Controller: Trigana 267, Oksibil, copy.

Hasanuddin: We are beginning our approach.

We would like to descend from 11,500 feet.

Controller: Confirm descent from 11,500.

Let me know when you are positioned over Oksibil.

Narrator: Oksibil is a small airport situated in a valley.

The mountains surrounding it can reach 11,000 feet.

Aryadin: Decreasing engine thrust.

Hasanuddin: 244 knots and dropping.

Curtis: Oksibil airport is in a mountainous area.

It sits in a valley.

And on top of that, they have very limited navigational aids

at that airport.

Narrator: Without the aid of advanced landing systems

seen at bigger airports,

pilots flying into Oksibil must keep the runway in sight

during the approach.

Curtis: A visual approach, as the name implies,

is an approach where the flight crew

has to have the airport and the surrounding area in sight.

Hasanuddin: Cabin crew prepare for landing.

Kurniawan: In preparation,

please straighten your seatback and stow your tray.

I'll be coming around to collect any garbage you may have.

Hasanuddin: Big plans with the family?

Aryadin: Yeah, looking forward to some time off.

Hasanuddin: Yes. It's been very busy these past few weeks.

♪

Aryadin: Flaps 15.

♪

♪

Gear down.

♪

♪

Controller: Wings Air 1250, confirm descent from 12,000.

Report when you are positioned over Oksibil.

Narrator: Five minutes later,

The air traffic controller at Oksibil realizes

Flight 267 hasn't reported in as expected.

Controller: Trigana 267, Oksibil.

Do you copy?

Trigana 267, Oksibil.

Do you copy?

[Static Hiss]

Curtis: One of the common things that happens

when an airplane doesn't land at an airport for some reason

is they may divert to another airfield.

The crew landing the aircraft

may have been too busy to call the airport

before diverting to another airfield.

Controller: Hey, this is Oksibil.

We've lost contact with Flight 267.

Have you heard from the pilots?

You haven't?

We might have a problem here.

Narrator: Word of the missing plane travels fast.

News Anchor: Overseas a search is underway

For an Indonesian plane carrying more than 50 people.

The flight lost contact today

over a remote area of the country.

Narrator: As the news spreads, investigators with Indonesia's

National Transportation Safety Committee, the KNKT,

fear the worst.

Ray Nurcahyo: My first impression

was that something wrong had happened.

It's not looking good.

Ony Wibowo: Well, maybe they just diverted

and haven't checked in yet.

[Translated] We tried to keep thinking positively

that there's a chance the aircraft

suffered from some damage

and ended up landing at a different airport

with limited communication.

Narrator: A search and rescue team is assembled,

consisting of army soldiers and search and rescue personnel.

Wibowo: They immediately began the search

around Oksibil airport

Because we learned from air traffic control

that its last location was quite close to the airport.

Narrator: Flight 267 was only 15 miles from Oksibil Airport

when it last checked in with air traffic control.

But search efforts come up empty...

until a pilot flying out of Oksibil Airport

spots smoke billowing from nearby Tanggo Mountain.

Woman, Translated: We don't have a lot of information.

We can only hope that the people on board have survived.

Narrator: The day after a pilot reported seeing smoke

in the mountains surrounding Oksibil, Indonesia,

the crash site of Trigana Flight 267 is located.

[Phone Rings]

Nurcahyo: Yeah.

1-4-0 degrees, 29 minutes,

51.18 seconds east.

Okay, got it. Thank you.

Narrator: The wreckage is at approximately 8,300 feet

on a ridge of Tanggo Mountain,

10 nautical miles from Oksibil Airport.

Wibowo: They went off course.

How did they end up over there?

Nurcahyo: We need to get eyes on that crash site.

I'm gonna send one of our guys up.

♪

Narrator: A search and rescue team

takes a KNKT investigator to the crash site.

At over 4,000 feet above ground level,

there are no roads, runways or clearings.

The only way to get to the crash site is on foot.

Nurcahyo: To reach the area, the team had to walk

for about four and five hours.

They had to climb in a quite steep, the dense vegetation.

It's quite hard to get to the site.

Narrator: After climbing for five hours,

the team finally reaches the crash site.

A field of debris stretches through Tanggo's thick forest.

♪

♪

♪

♪

[Phone Rings]

Nurcahyo: Go ahead, Oksibil.

Investigator: Jakarta, we've reached the crash site.

No survivors.

Nurcahyo: Okay.

Once you catch your breath,

the number one priority is to find the black boxes.

Investigator: Okay.

Hey, guys.

Check it out.

We're looking for the FDR and the CVR.

Narrator: Because of the remote location,

bringing much of the wreckage down from the mountain

will be impossible.

So the investigator at the scene must document as much as he can

and send photos back to headquarters.

[Click]

While the search and rescue team

retrieves the remains of the 54 people who died...

The KNKT investigator tries to determine

exactly how the plane hit the mountain.

The trees surrounding the crash site

provide an important clue.

They are sheared off in a straight line,

indicating the plane flew head-on into the mountain.

Investigator: That's right. There's no sign they pulled up.

Narrator: How could the crew have flown

straight into a mountain that's so well known to pilots?

The investigation team's top priority will be

to figure out what was happening in the cockpit

at the time of the crash.

♪

The plane's flight data recorder and cockpit voice recorder

can be invaluable tools for the investigation.

♪

♪

The damaged black boxes are shipped out for analysis.

♪

♪

In the days that follow...

family members mourn

while they wait for the recovery of loved ones.

[Speaking Indonesian]

Man, Translated: Search and rescue,

along with the local help,

have been successful in retrieving the 54 bodies.

Narrator: They are desperate to know what caused the crash

that killed everyone on the flight.

It's up to KNKT investigators to figure that out.

They first need to determine why the plane ended up off course.

Nurcahyo: Blue's the flight path in the approach chart.

Here's where they crashed.

Narrator: Flight 267 crashed about 10 miles west

of the approach path into Oksibil airport.

Nurcahyo: They went right and ended up here.

Wibowo: I'd like to know more about the terrain around here.

Narrator: To determine the height of the terrain

along the flight's path,

investigators use special software

That generates topographical data for the area.

Wibowo: When we learned about the location of the crash,

we had some difficulties.

We realized it would be a challenge for us

to identify the terrain height of the plane's debris.

[Sighs]

Narrator: The topographical map reveals

that the pilots were flying a treacherous route.

Nurcahyo: They were surrounded by mountains

as high as 9,000 feet.

Wibowo: Why didn't they fly above them?

Narrator: Investigators wonder

if there was a mechanical problem with the plane

that caused it to plow into a mountain.

Nurcahyo: Maybe the FDR can tell us.

Curtis: Certainly there would have been something

in the flight data recorder

that may have given an indication

that some system on the aircraft

wasn't operating as it should have.

Narrator: When the recovered flight data arrives,

Nurcahyo and Wibowo are eager to get their first look

at how the plane was functioning at the time of the crash.

Nurcahyo: Wait a minute.

This doesn't make any sense.

This says the plane was going east, not south.

[Speaking Indonesian]

Wibowo: We were able to download this data

that contained all the flight information,

but the flight data we recovered didn't correlate

with what might have happened on the day of the crash.

And the time of day is wrong.

So is the speed.

The flight data was not from the day of the accident.

Narrator: Digging even deeper into the data,

the investigators come to a disturbing realization:

the recorder wasn't working at the time of the crash.

Nurcahyo: Useless.

We found that the FDR

had been experiencing several problems since 2012.

It had been installed on that aircraft

and found fault and then offloaded,

went to the shop for repair, back again to the aircraft.

Narrator: The malfunctioning FDR

had no connection to the accident,

making it much harder for Nurcahyo and Wibowo

to figure out what caused it.

Investigators still don't know

why Flight 267 slammed into the side of a mountain.

In the Indonesian province of Papua,

the families of the 54 people on board Trigana Flight 267

lay their loved ones to rest...

including flight attendant Dita Amelia Kurniawan.

Overcome by grief, they want answers as to what happened.

News Anchor: Authorities have released new pictures

showing the wreckage from the Indonesian passenger plane

that crashed in the country's remote eastern region

over the weekend.

Narrator: KNKT investigators are facing intense pressure

to determine why Flight 267 crashed.

Without recorded flight data,

the plane's cockpit voice recorder

is investigators' last hope to learn what was happening

in the air at the time of the crash.

Curtis: They would be able to understand

what was said to and from air traffic control,

and they can also understand any kind of communication,

formal or informal, that was taking place within the cockpit.

That can be a huge indicator

of something going wrong with that flight.

Narrator: Fortunately, the CVR data is successfully recovered.

Nurcahyo: Alright, we're ready?

Okay, play it.

Narrator: The CVR contains two hours of audio,

including from the two flights prior to the accident flight.

Hasanuddin: I'll call down and let them know we're coming.

Narrator: Investigators first listen

to the pilots' flight into Oksibil from earlier in the day,

in the hopes of finding clues.

Aryadin: Oksibil, Trigana 267.

Controller: Trigana 267, Oksibil, copy.

Aryadin: We are beginning our approach.

We would like to descend from 11,500 feet.

Controller: Confirm descent from 11,500.

Let me know when you are positioned over Oksibil.

Aryadin: Uh, Oksibil, we won't be over the airport.

We're going to fly direct to a left base leg to runway 11.

Controller: Copy that.

Nurcahyo: Left base leg?

That's not what it says in the charts.

Wibowo: They took a shortcut?

Narrator: The CVR reveals that the pilots

made an intentional deviation in their approach

during their prior flight into Oksibil.

The official approach directs aircraft

to fly over the airport and then circle back and land.

But on the earlier flight, the pilots flew

directly to runway 11...

without looping around.

Aryadin: 500 feet.

Landing flaps and propeller speed are set and confirmed.

Narrator: After flying the shorter approach,

the pilots landed on the runway at Oksibil...

without incident.

Investigators wonder if the pilots tried

to repeat that shorter approach a few hours later,

but with a very different result.

Nurcahyo: Let's skip ahead to the accident flight.

Hasanuddin: We're at 2,000 feet.

Want to turn on the autopilot?

Aryadin: Autopilot engaged.

Controller: Confirm descent from 11,500.

Let me know when you are positioned over Oksibil.

Hasanuddin: Oksibil, we're flying direct

to a left base leg to runway 11.

Controller: Copy that.

Nurcahyo: So they take the same shortcut

for the accident flight.

Narrator: The last flight proceeds

much like the crew's earlier flight into Oksibil.

Hasanuddin: Big plans with the family?

Narrator: Investigators listen closely for any signs of danger.

Aryadin: Yeah, looking forward to some time off.

Hasanuddin: It's been very busy these past few weeks.

Narrator: It's what they don't hear that raises questions.

Wibowo: They're not doing their approach briefing and checklist.

Curtis: Briefings and checklists serve several functions.

One of the key functions is to give the flight crew

a better understanding of their environment.

Not doing that makes it less likely

that the pilot will remember to do certain things,

or to take certain precautions,

or to be aware of certain hazards

that could be happening on that particular flight.

Narrator: The team now knows that the crew

missed a crucial step on their approach.

But can the recording reveal anything

about how the plane was functioning mechanically

just before the crash?

Nurcahyo: Can you turn that up?

[Humming]

Picking up anything with the engines?

Wibowo: We tried to analyze the sound of the engine.

Hasanuddin: Flaps 15.

Gear down.

Wibowo: Based on the frequency and amplitude

of the sound of the propeller,

we concluded that the engine and propeller

were both in good shape.

Nothing unusual.

Nurcahyo: On the last phase of the flight, the CVR recorded

that the condition in the cockpit was normal.

Narrator: While listening to the final moments of the crash,

investigators make a baffling discovery.

[Recording Stops]

Nurcahyo: That's it?

Normally at the last second of the flight

the pilot would have been scream or do something.

It happened so fast.

It sounds like they didn't even see the mountain.

♪

♪

[Crash]

Narrator: Investigators have a theory

about the crash of Trigana Flight 267.

They believe that weather

may have obscured the pilots' view of the mountain.

The team scrutinizes weather data recorded

less than an hour before the crash.

Wibowo: Oksibil was covered by dense clouds.

Narrator: The data reveals that at the time of the accident

Flight 267 would have been flying

through an area of low clouds.

Nurcahyo: The clouds could have been quite dense here.

The pilots wouldn't have been able to see much.

Wibowo: Yeah, but you know Papua.

You never really know what the weather is gonna be like

unless you're looking out the window yourself.

Soejatman: It is difficult to determine

whether the flight was in cloudy conditions or not.

In the mountainous area it can be cloudy in one valley,

it can be perfectly clear in another valley,

and you go into another valley and it's completely covered.

Narrator: To get a firsthand account

of the weather conditions on the day of the accident,

investigators speak to the controller on duty.

Nurcahyo: What was the weather like

on their first flight into Oksibil?

Controller: It looked mostly clear.

Nurcahyo: And did the weather change on their second flight?

Controller: Yeah. The clouds rolled in.

It was so dense that I couldn't even see the mountains.

Narrator: The controller tells the investigators

that he did inform the pilots about the cloudy conditions.

Hasanuddin: Oksibil, Trigana 267.

Controller: Trigana 267, Oksibil. Go ahead.

Hasanuddin: How's the weather looking for our approach?

Controller: You've got a cloud base of 8,000 feet.

Narrator: The pilots' decision to continue flying

with so much cloud cover surprises investigators.

Wibowo: In principle, when flying using visual rules,

only one rule applies:

to arrive safely

you must maintain visual contact at all times.

Aryadin: Gear down.

Nurcahyo: The visual approach is not allowed to be done

in a cloudy condition,

so when the cloudy condition

and they're unable to see the whole mountain,

they should follow the procedures.

Narrator: But instead of following procedure...

Nurcahyo: They knew the base of the clouds was 8,000 feet.

Narrator:...they took a gamble

that they would eventually catch sight of the runway.

Nurcahyo: They were descending,

expecting to drop out of the clouds at any minute.

Wibowo: Instead, they crash into a mountain

at 8,300 feet.

♪

♪

We still don't know why they didn't know

they were in the path of a mountain.

Narrator: With modern aviation technology,

even if the pilots didn't see the mountain,

the plane should have.

So why didn't they know they were heading straight into one?

Nurcahyo: We need to check their warning system.

[Speaking Indonesian]

Wibowo: When a plane is in close proximity to terrain

or about to hit an object,

there's a warning system that warns the pilot

when the plane is very close to terrain.

Narrator: The warning system uses GPS and a terrain database

to monitor an aircraft's height

above the surrounding terrain.

If the plane comes too close to the ground,

the system will warn the flight crew with audio messages...

Computer: Terrain, terrain. Pull up!

Narrator:...so pilots know to increase their altitude.

Nurcahyo: This is the profile of the mountain.

This is our flight descending through clouds,

and the pilots can't see the ridge in front of them.

Their proximity to the terrain

would have activated the terrain caution here,

60 seconds before impact.

Now, the pull-up warning should have gone off here,

30 seconds before.

Were there any warnings going off in the cockpit?

Wibowo: No. There's nothing in the transcript.

Narrator: The absence of audible alerts

leads investigators to wonder

if the plane's warning system was working properly.

The team knows the FDR wasn't properly maintained.

Could the same be true for the warning system?

Wibowo: We tried to dig deeper to see if the warning system

had been properly installed in Trigana 267.

Nurcahyo: Last maintenance was performed on August 14th,

two days before the crash.

It appeared to be working normally.

Wibowo: When we looked into the maintenance record,

We did not find any significant mention

of something broken in the warning system.

Narrator: With a faulty warning system ruled out,

investigators now wonder

if the terrain data used by the system was accurate.

Nurcahyo: This area is not very well mapped.

Some of the Papua area was very rough data.

The precision of the data

was not as close to the actual conditions.

Soejatman: If you fly in a mountainous area,

the database itself might not detect

the fine details of the contour of the terrain around you.

Narrator: Did the lack of accurate terrain data mean

the system wasn't able to warn pilots

when they were too close to the mountainous terrain?

The Trigana 267 investigators

decide to speak with Trigana pilots

who regularly fly in the Oksibil area

to find out if they received terrain warnings.

The pilots report that not only did the system provide warnings,

It gave an excessive amount of false warnings

due to the poor quality terrain data.

Soejatman: If you're flying within a mountainous area,

it can give you a false warning or unnecessary warnings.

Wibowo: Was this area prone to false alarms?

Soejatman: Imagine you are trying to land

in a small airport in the middle of the valley.

You can see the airport in front of you.

You're in visual conditions,

and then the system starts giving you a warning.

Computer: Terrain, terrain. Pull up!

Soejatman: You think, well, I can see

the airport in front of me.

I can see the terrain behind it.

That, that warning is, is annoying.

Wibowo: And what do you normally do

when you keep getting these false warnings?

Hold on.

He says sometimes

they deliberately pull the circuit breaker.

Sorry, go on.

Narrator: It's an astonishing finding.

Curtis: It might have been because of spurious

or inappropriate warnings by the system.

That is, it's telling you that you're close to the ground

when in fact you're not.

This is what I like to call the "Boy Who Cried Wolf" syndrome.

Computer: Terrain, terrain. Pull up!

Curtis: You know, the other flights we've done,

we've had no problem.

Let's just turn this thing off.

Computer: Terrain.

Soejatman: But if you pull the circuit breaker,

you might forget that you've pulled it.

And that's not good,

because if you're going into a valley when it's still cloudy,

you still need your systems

no matter how unreliable that is.

Any warning you get,

if you don't have visual contact with the ground,

You follow it.

Wibowo: Okay, thank you.

They just pull the breaker to get rid of the false warnings.

Apparently it's common practice.

Nurcahyo: Are you kidding me?

Narrator: This revelation leads investigators

to ask themselves a difficult question.

Did Flight 267 lack terrain warnings...

because the pilots intentionally turned the system off?

Curtis: Both the captain and the first officer

were very experienced.

In fact, I think these pilots were much more experienced

than the average turboprop pilot.

Hasanuddin: We've reached cruising altitude, 11,500.

Wibowo: Is it possible the pilots were overconfident

because they had flown this route so often?

Nurcahyo: We also asking questions to some pilots,

particularly pilots that had experience

flying with these two accident pilots.

Wibowo: Will you excuse me?

I now have a pilot on the line

that says he's personally seen Captain Hasanuddin

pulling the circuit breaker.

Nurcahyo: We found some information

that some co-pilots flying with the captain

knew the captain had the habit to inactivate the system.

Hasanuddin: Decreasing engine thrust.

Computer: Terrain, terrain. Pull up!

Hasanuddin: Yeah, yeah, yeah.

Computer: Terrain, terrain.

Curtis: Overconfidence and complacency

are two of the issues that are common in aviation,

and what it leads to

is certain equipment could be turned off

because the pilots think that their experience

in other aspects of flight will more than compensate.

Computer: Terrain, terrain.

Hasanuddin: Yeah, yeah, yeah.

Curtis: When a flight crew operates deliberately

with an aircraft that's not fully capable,

They're increasing the risk of that flight.

♪

Narrator: Looking through the captain's records,

investigators discover that the airline knew about his habit

of pulling the circuit breaker.

Nurcahyo: Hmm.

It says here that they scheduled

a briefing with him to address it.

Based on this information,

we assumed that that day, on the accident day,

the captain also inactivated the system.

Computer: Terrain, terrain. Pull up! Terrain, terrain.

Hasanuddin: I got this.

Computer: Pull up! Terrain, terrain. Pull up!

Narrator: Investigators now believe that the pilots

intentionally disabled their warning system

on an earlier flight that day...

and then never reset it.

Nurcahyo: If the system was active,

I'm sure that the accident would have been avoided

Because the last seconds of the flight before the impact,

the system will scream "Pull up, pull up!"

The pilot would have taken action to save the flight.

[Crash]

Narrator: No wreckage relating to the warning system

is recovered from the crash site.

Investigators can't know for sure

if the circuit breaker had been pulled.

But even if the pilots were overly confident

they could make the approach

without the aid of the warning system,

there's still something else that doesn't add up.

Nurcahyo: The pilots flew into this area all the time.

Why were they flying so close to the mountains

in the first place?

Narrator: Investigators are trying to determine

why pilots who were very familiar with the Oksibil area

would risk flying so close to the mountains below them.

Nurcahyo: Can you pull up this approach chart?

♪

Narrator: A diagram in the corner of the approach chart

informs pilots about the safe minimum altitudes

in areas surrounding the approach path.

Nurcahyo: The approach chart says the minimum safe altitude

in this area is 8,000 feet.

Flight 267 crashed at 8,300 feet.

Curtis: They were adhering strictly to the information

that was there in the approach chart,

but the information was wrong, and that wrong information

put them at risk for colliding with terrain.

Hasanuddin: We're good to 8,000 feet.

Narrator: Investigators believe the pilots were aware

of the minimum safe altitude published on the approach chart.

It's the last piece of the puzzle.

Nurcahyo: The crew thinks they're safe down to 8,000 feet.

And on the accident day,

the base of the clouds is 8,000 feet.

Wibowo: It makes the pilots feel

as long as they're in the clouds, they're safe.

Aryadin: Decreasing engine thrust.

Hasanuddin: 244 knots and dropping.

Cabin crew, prepare for landing.

Curtis: What struck me more than anything

was that this was so very preventable.

This was a controlled flight into terrain event.

Narrator: The investigation has uncovered

a confluence of factors that led to the crash of Flight 267.

Hasanuddin: Big plans with the family?

Aryadin: Yeah, looking forward to some time off.

Hasanuddin: It's been very busy these past few weeks.

Narrator: At the core:

two pilots who had grown overconfident

flying the route so many times before.

Computer: Terrain, terrain. Pull up!

Terrain, terrain. Pull up!

Terrain, terrain. Pull up!

Terrain, terrain.

Hasanuddin: I got this.

Computer: Pull up! Terrain, terrain.

Narrator: Because the captain had a reputation

For pulling the ground proximity warning system circuit breaker,

investigators suspect he disabled the system

on an earlier flight that day.

Then, on the last flight into oksibil...

Aryadin: We're beginning our approach.

We would like to descend from 11,500 feet.

Controller: Confirm descent from 11,500.

Let me know when you are positioned over Oksibil.

Aryadin: Gear down.

Narrator: The pilots failed to do their approach briefing

or safety checks and relied on faulty approach charts.

Curtis: There are three key things

that could have avoided this accident:

adherence to standardized procedures,

the use of warning systems,

and the use of cockpit resource management techniques,

which could be as simple as,

is there a checklist that should be used?

♪

[Crash]

Three very clear areas

where any one of them would have prevented this accident.

None of them happened.

Narrator: In the aftermath of Flight 267,

the KNKT makes a series of safety recommendations

that will make the skies of Indonesia safer.

Soejatman: First of all, the charts needed to be updated.

Wibowo: We also asked the airline operator

to request the database for the warning system

to be updated with a more accurate version.

Up to now we noticed a significant drop

in warning system violations.

Also, since the approach chart for Oksibil has been fixed,

we've seen a positive impact in terms of flight safety in Papua.

[Speaking Indonesian]

Curtis: The lessons from this accident,

the insights from the investigation won't go away.

They'll be here decades from now.

I'm confident that the insights in this report

will influence design of equipment,

Will influence the design of procedures,

will influence the kind of hazards

that flight crews will look out for in the future.