Mayday (2013) s16e09 Episode Script
Deadly Solution
An Airbus A320 en route to Singapore, disappears while flying over the Java Sea.
It crossed my mind "What could have caused it? Is it an act of terrorism, sabotage, something extreme happening to the aircraft?" For days, a massive search and rescue effort turns up nothing.
A crash at sea is challenging.
It's difficult to locate because you usually don't have the full flight path down to the surface of the ocean.
What they find paints a confounding picture of the final minutes of flight.
The plane started to bank.
We were very surprised by this action.
What are they doing? The investigation uncovers a single tragic misunderstanding that claimed the lives of 162 people.
NARRATOR: AirAsia Flight 8501, cruises high above the Java Sea north of Indonesia.
It's a few days after Christmas and many of the 156 passengers aboard the Airbus A320 are on holiday.
The pilot in command is 53-year-old Captain Iriyanto.
He's highly experienced with more than 20,000 hours in the air.
His first officer is French national Remi Emmanuel Plesel.
He is 46 with about 2000 flight hours, much of it on the Airbus.
On this particular leg, it was the first officer that was manipulating the controls.
The captain was in command of the flight but was performing the duties of the pilot monitoring, or the non-flying pilot.
Today's flight originated in the Indonesian city of Surabaya.
It's heading across the Java Sea to Singapore.
Total flight time is expected to be two hours.
- It looks like weather ahead.
- No.
I don't like the looks of that.
Twenty-two minutes into the flight, the pilots notice bad weather ahead on their radar.
Anti-ice? Anti-ice, on.
The crew would definitely be taking care to avoid penetrating these thunderstorms because it contains possibly extreme turbulence, hail, lightning, everything that the air crew don't want to expose themselves and the passengers to.
(PHONE RINGS) The captain instructs the flight attendant to prepare the cabin for turbulence.
Ladies and gentlemen, please return to your seats and fasten seatbelts.
Khairunnisa Haidar Fauzi is one of four flight attendants helping to look after the passengers as they cruise at 32,000 feet.
As an additional precaution, the captain decides to increase altitude, to go above the storm clouds in their path.
I'm gonna radio for a higher cruise, - get around that weather.
- Good idea.
But before the captain can contact air traffic control, he gets a fault warning from the flight computer.
ECAM actions? The plane's sophisticated computers give the pilots step-by-step instructions on how to fix the issue.
FAC 1 off and on.
FAC 2 off and on.
Warning cleared.
Computers control most of the Airbus A320's systems.
There are basically seven computers that fly the aircraft and they add a lot of helpful features that take workload away from the pilot.
Pilots are trained to follow the instructions given by the aircraft's computers.
(BEEPING) A few minutes later, the warning sounds again.
Same.
FAC 1 off and on.
After addressing the fault warning, the captain radios air-traffic control to request the higher flight level.
OK.
So Jakarta Air-Traffic Control, AirAsia 8501, request climb to 38,000.
The Jakarta air-traffic controller has had an uneventful night.
He soon clears the pilots to climb, but to a slightly lower altitude than the 38,000 feet requested.
AirAsia 8501, you are cleared to 3-4-0.
After permitting them to climb, the controller waits for confirmation But the pilots are distracted by a third alarm.
Here we go again.
- ECAM actions.
- FAC 1 off and on.
The controller hasn't heard back so he repeats his message.
AirAsia 8501, you are cleared to 3-4-0.
It's very annoying and very time consuming to deal with this recurring problem.
- Enough of this.
- ECAM actions.
The controller still hasn't heard confirmation from the pilots.
AirAsia 8501, do you read me? Please acknowledge.
But in the cockpit, the fault warnings have escalated.
AirAsia 8501, do you read me? Please acknowledge.
In the cabin, passengers have no idea their pilots are struggling to maintain control of the plane.
The pilots now notice that the plane is rolling sharply left.
Level.
OK.
Level.
Something is going terribly wrong with Flight 8501.
The first officer is struggling.
Level! But soon the plane is rolling again.
- Level! - I'm trying.
The pilots can't seem to regain control.
It's not responding.
AirAsia 8501, please confirm.
You are climbing to flight level 3-4-0.
The controller still hasn't heard confirmation from the pilots when the plane starts to climb towards 34,000 feet and then continues climbing steeply even higher.
No airline passenger would have ever experienced something like this under normal circumstances before.
It would have been a very violent, shocking manoeuvre.
- Pull down! - It's not correcting.
The plane seems to have taken on a life of its own.
It climbs higher and higher as the pilots fight to level off.
Then, inexplicably, the plane starts to drop.
That would certainly cause near panic in some people.
Other people would be waiting for the pilots to quote "fix it.
" - Altitude! - I see it! Flight 8501 is plummeting from the sky, speeding toward the ocean below.
The rate of descent here was very, very high.
It seems the pilots can do nothing to save their plane.
- Pull! - It's not correcting.
- What's going on? Max power.
- Slowly.
(SCREAMING) Forty-three minutes into what should have been a two-hour flight Eugh! .
.
AirAsia Flight 8501 disappears from radar.
- Pull! - I'm trying! - Pull! - It's not correcting! Eugh.
News quickly spreads of the mysterious disappearance of a commercial flight to Singapore.
The loss of AirAsia 8501 was a classic case of a flight degenerating from mundane, normal cruise conditions to the loss of the aircraft in a span of just 20 minutes.
Within hours, relatives of the 162 passengers and crew are demanding answers.
How could an airplane just disappear? All the authorities know is that the plane vanished from radar somewhere over the Java Sea.
Speculation runs wild about what could have brought the airliner down.
It crossed my mind "What could have caused it? Is it an act of terrorism, sabotage, something extreme happening to the aircraft?" But it was very difficult to come up with a clear picture on the first news reports as to what had taken place.
It's been only a few months since Malaysia Airlines flight 370, disappeared in eerily similar circumstances, vanishing from radar without sending any mayday call.
Search and rescue vessels are dispatched, but combing the vast and choppy sea between Sumatra and Borneo is a mammoth task.
An international team of air-safety investigators flies in to join the local experts in Jakarta.
Ray Nurcahyo is an air-crash investigator with the Indonesian National Transportation Safety Committee.
The air-traffic-control radar data is our main source to detect the location of the aircraft.
They begin by interviewing the air-traffic controller.
So can you tell me what happened? They were the ones who could tell us a little bit more about what had happened.
They had seen the plane trajectory, the plane flight path.
They learn that the plane was flying towards an area of bad weather.
When you start out in an investigation, you look at everything.
In this case, there were weather considerations.
And then? Then they started losing altitude fast.
And then it disappeared from radar at 24,000 feet.
Thank you very much.
How could this plane being in cruising altitude, suddenly climb and fall with a very high rate of descent? Could the aircraft have lost engine power in a violent storm? Can I get the weather overlay for this map, please? Investigators examine detailed weather charts from the day of the accident.
There were thunderstorms here and here.
It was monsoon season and so there's a lot of thunderstorms.
They can do damage to the airplane that It's something that you learn early as a pilot and it's something that you adhere to very strongly.
You do not fly through thunderstorms.
Then they start mapping the flight track to see if the plane - could have entered the storms.
- They were at cruising altitude.
Then here they asked for deviation.
They made it here and then they started to drop.
They almost flew into the first storm but then just missed it.
Bad weather, the first possible explanation for the disappearance of Flight 8501, proves to be a dead end.
This is the spot they were last seen on radar.
Based on Flight 8501's last radar coordinates, investigators have at least narrowed down the search area.
Dozens of rescue vessels and aircraft from multiple countries scour the target area.
A crash at sea is challenging.
It's difficult to locate because you usually don't have the full flight path down to the surface of the ocean.
The Indonesian President decides to address a nation in mourning.
Two days into the search, the first pieces of wreckage are recovered from the Karimata Strait in the Java Sea.
Soon searchers are finding bodies.
Among the first is that of flight attendant Khairunnisa Haidar Fauzi.
In a moving tribute, hundreds attend her funeral.
Funerals for many more follow.
Of the 162 passengers and crew, there are no survivors.
As the wreckage is brought in for examination, investigators can see that the task ahead of them is daunting.
Why would a highly sophisticated airliner, flying at cruising altitude, suddenly fall from the sky? We had a lot of little pieces everywhere.
My first reaction was, it's not gonna be easy.
Is it all like this? A crash at sea is challenging because usually the main interesting parts are underwater and that's a little bit difficult to get them.
With much of the plane still missing at the bottom of the sea, investigators study debris found floating on the surface.
To see if the plane exploded, they look for distinctive smaller pieces with burnt edges.
The debris that was recovered did not exhibit any tell-tale signs of having been subject to a bomb explosion.
This plane didn't blow up.
The pieces of AirAsia 8501 are large and clean.
We could eliminate a possible in-flight break up.
It's a step forward, but unless they can find the black boxes, the mystery of AirAsia Flight 8501 may never be solved.
The flight recorders offer the only hope of figuring out what was happening in the cockpit.
The search for them goes into high gear.
All black boxes are equipped with an electronic beacon that transmits a signal under water.
Ship-based sonar systems can detect the signal and help guide searchers towards the black boxes.
When we get this signal, we are in a range of about 2,000m from them.
So, this helps us narrow it down to where they are and then the divers then have to try to find them.
But weather complicates the search.
The depth was about 40 metres and the sea was rough.
And we couldn't go every day we wanted to go.
So, we had to adapt our strategy to the weather.
After a two-week search, they finally succeed.
We were relieved to get the boxes 'cause this was a real major step towards the explanation of what had happened.
Investigators start by listening to the cockpit voice recording.
It should reveal pilot conversations and other sounds from inside the cockpit of Flight 8501.
OK, let's start when they ask permission to climb.
Play recording.
Jakarta Air-Traffic Control, AirAsia 8501 request climb to 38,000 to clear storm clouds.
Up to that point the flight was normal.
It was uneventful.
Continue recording.
Almost immediately, investigators make a discovery.
- ECAM actions.
- FAC 1 off and on.
- FAC 2 off and on.
- (BLEEP) Warning cleared.
They were dealing with some kind of warning.
Play recording.
(BLEEPING) - ECAM actions? - Same.
OK.
The warning came back.
They were getting continual fault warnings through the what's called an ECAM system, Electronic Central Aircraft Monitoring System.
Play recording.
- Here we go again.
- ECAM actions.
FAC 1 off and on.
FAC 2 off and on.
- It's cleared.
- At this point, the crew's behaviour was standard, was normal.
They were quiet.
They were communicating on what checklists to apply.
AirAsia 8501, you are cleared to 3-4-0.
OK, stop.
We know from the controller that he never heard back from them again.
Play.
- (BLEEPING) - There it is again.
ECAM actions.
Then the recording reveals something surprising.
No.
I've got a better idea.
The captain appears to have done something different - and then there's a new warning.
- Hold recording.
Now the autopilot has disengaged.
An unexpected disengagement of the auto-throttle and auto-thrust system results in a pretty loud warning.
This is a very serious concern to the investigators.
RECORDING: (BLEEPING) - What was that? - OK, let's see what we have.
- Master caution? Why? - Checking (BLEEPING CONTINUES) (ALARM SOUNDS) .
.
level.
Level.
Investigators now hear yet another cockpit warning.
Stall warning.
The airplane would have warnings to tell the pilot that they were getting close to an aerodynamic stall.
Pull! Slowly! - What's going on? - Pull! NARRATOR: An aerodynamic stall occurs when the angle between the wings and the oncoming air gets too steep.
The amount of air flowing over the wings is reduced.
The aircraft loses lift and can no longer stay aloft.
It's a highly uncommon event to have an Airbus stall, particularly in cruise, because it's protected from stalling.
Normally the computer won't allow the aircraft to stall.
It won't allow the wings to go at too high an angle to the airflow and stall the aircraft.
NARRATOR: What caused this technically advanced plane to stall? The autopilot disconnects.
The aircraft stalls.
They struggle to recover.
It makes no sense.
Only the FDR data can reveal what was happening with the aircraft the moment the crisis hit.
Until that data is ready for analysis, the deadly mid-air stall remains a mystery.
What were you guys struggling with? One of the questions that the investigators would have faced is why and how did an aircraft that is supposed to be stall proof end up stalling?" Pull down.
Slowly! The flight data recorder should provide answers, but it needs to be flushed of salt water before it can be read.
In the meantime, investigators pull the plane's maintenance records to look for clues.
They soon make a discovery.
The aircraft seems to have an issue with its RTLU.
RTLU is the Rudder Travel Limit Unit.
The plane had had a history of RTLU failures.
The Rudder Travel Limit Unit is a computerised component that prevents the rudder on the tail from deflecting too far in either direction when the plane is travelling at high speed.
If the flight computer detects any problems with its rudder limiter, it sends a warning to the cockpit.
Records show the aircraft's Rudder Travel Limit Unit had been malfunctioning for almost a year.
Twenty-three reports of the exact same failure.
The RTLU failures on this particular airframe had become increasingly frequent.
There were 11 in the last couple of months and 23 in the preceding period, which is highly unusual.
That seems like a lot of failures with the RTLU.
Could these be connected to the mystery warnings the pilots were experiencing? It could be a major breakthrough.
Three days before the crash there were two exact same failures.
Why was this happening? After each failure, maintenance workers reset the RTLU.
TRANSLATION : As long as the reset resulted in the computer to prompt pass, maintenance personnel doesn't have to investigate further.
They just kept resetting it and then putting it back in service.
But they never found a permanent fix.
They were returning the airplane to service after reset and from a legal standpoint it did clear the problem.
But obviously, whatever the fault was they hadn't found it because the problem continued to reoccur.
The aircraft seemed to operate perfectly despite the warnings.
Even the day before the crash, the plane had successfully flown from Surabaya to Kuala Lumpur.
Have we got the unit? The plane's RTLU is among the wreckage that's been recovered from the Java Sea.
Let's send it back to the manufacturer and see if they can find something.
The unit is sent to France for analysis.
Finally, investigators get to examine a key piece of evidence, the flight data recorder.
If they can download all the flight data, it should provide a detailed picture of exactly what was happening with the electrical and mechanical control systems on the aircraft.
We worked with the Indonesian Investigation Authority in extracting the data, which requires a lot of precautions since the flight recorders had been immersed.
Move it down too, a little bit.
On examination, they discover the data board has been damaged by the impact of the crash.
It's uncertain whether the information they desperately need will be retrievable.
The download begins.
Even though the condition of the black box was damaged, we managed to recover all of the data.
Success.
"OK, so let's start with those chime warnings.
OK.
So here's the first warning.
It clearly was the RTLU.
They do the fix, simply resetting the entire system.
The procedure to reset the system was much like your PC, rebooting the PC.
They only had to turn the system off and turn it back on again.
FAC 2 off and on.
Two more times the RTLU warning goes off and each time they did the right thing.
Then it went off on a fourth time.
Then suddenly there was a glitch.
What did they do different? After the fourth time, the warnings change.
There is now a fault with the aircraft's two main computers, known as the flight augmentation computers.
Put the new data up on that screen.
Something caused both computers to fail at the same time.
But nothing in the data shows what the crew did differently after the last warning.
What does come to light, is that when the autopilot disengaged the rudder moved slightly.
Now let's see.
The plane started to bank to the left.
The electrical interruption on the flight control computers created a rudder movement of about two degrees to the left.
Two degrees does not sound like a lot, but at the speed they were flying, it's exactly what caused them to roll left 54 degrees.
That's almost twice the normal bank that you would feel in an airliner.
Now look at this.
It took them nine seconds to do anything about the bank.
Despite the steep bank angle, it seems the crew was slow to react and level the plane.
During the first nine seconds, there was no crew inputs on the controls following this roll that reached 54 degrees.
Then the first officer suddenly reacts, pulling hard to the right, then left again and just as suddenly he starts to pull up.
All they had to do was steady the plane.
What were they doing? The FDR data shows that the plane climbed steeper and steeper until they reach a remarkable 45-degree pitch up.
Then it stalled.
Investigators know that the captain did something different, something that led to a computer glitch causing the autopilot to disconnect and the plane to bank sharply.
But they don't know what he did.
The single event of autopilot, autothrottle disengagement sends the investigators in two different directions.
One, what caused it? Two, how did the crew handle it? As investigators struggle to answer puzzling questions about Flight 8501 and its crew (PHONE RINGS) Hello? NTSC.
.
.
they get an important new lead.
Wait, wait.
Slow down.
What happened? A mysterious action by the captain to solve a routine error, appears to have set off a deadly sequence of events.
Investigators are still trying to understand what happened when they receive some new information.
Start from the beginning.
Where was he? Three days before the accident, on December 25, this same captain was about to fly from Indonesia to Kuala Lumpur when he had an RTLU malfunction.
He asked for an engineer to come to the cockpit and try to fix that.
- RTLU problem again? - Yeah, it just keeps coming back.
The maintenance engineer rebooted the system - There.
- Ah (BLEEPING) .
.
but the problem came back.
I've got an idea.
He then pulled the circuit breakers for the main computer.
Maintenance on the ground has a very specific list of circuit breakers that says you can utilise pulling these circuit breakers to reset computers within the airplane.
As the captain watched, the problem was fixed.
- (BLEEP) - Problem solved.
And can I do the same thing if it happens again? Yeah, just do what the ECAM tells you to do.
Don't tell me he tried to do that in the air.
Investigators think that they now know what the captain did that led to the crisis in the cockpit.
Begin simulation.
To see if they're right, they decide to simulate the cockpit warnings heard in flight.
OK, so let's start with the RTLU warnings.
(BLEEPING) FAC 1 off.
FAC 2 off.
Good.
(BLEEPING) Enough of this.
After the fourth RTLU warning, he takes a new approach.
- ECAM actions? - No.
I've got a better idea.
Investigators believe the captain pulled two critical circuit breakers.
Captain pulls circuit breaker one.
The result is immediate.
And there goes the autopilot disconnect warning.
Investigators can now be certain of one thing.
This had to be what he did.
He was perhaps copying what he'd seen the ground engineer do but of course the consequences in flight to disabling critical systems are quite different.
The captain wrongly assumed that if it worked on the ground, it'll work in flight.
TRANSLATION: The circuit breaker, which is part of the flight augmentation computer, is something that should never be pulled out in the air.
Pulling the circuit breakers has devastating consequences the captain didn't anticipate.
Unfortunately, he was not pulling circuit breakers that affected only the rudder limiter system but ones that also disabled the flight augmentation computer, which tripped the autopilot, the autothrottle and all the normal mode protections that the aircraft had.
The plane begins to roll.
Over the next nine seconds, it rolls 54 degrees, yet no-one does anything to stop it.
What took them so long to react? The first officer would have been looking here and here when the autopilot warning was disconnected and the captain was still standing behind the first officer's seat.
What was that? It's likely that neither pilot was looking at the attitude indicator that showed the plane was banking.
That's why it took them nine seconds to notice what this gauge here was telling them.
As the plane started to roll, the first officer was focused on the fault warnings.
He didn't notice that the plane was banking until the captain sat back down again.
- Oh, my god.
- Oh! Despite losing control of these systems, the high-tech plane did have the capacity to get back on course.
After the initial roll, why didn't the first officer just steady the plane and re-engage the autopilot? Investigators have to try to understand what was going on inside the pilots' heads.
The co-pilot's movement of the stick to its extreme right-most position, resulted in a very violent roll to the right, two to three times what would be programmed as the maximum for an Airbus normally.
In an attempt to understand the first officer's actions, investigators study how the human brain behaves in flight.
A sense of balance is maintained by liquid levels in the ear canals.
When that shifts violently, the brain can get mixed signals that affect balance.
The FDR data shows how dramatic the plane's movements were.
So the plane rolled 54 degrees left and he pulled back almost level in just two seconds.
That would scramble anybody's gyros.
Maybe that was the confusion? As soon as the first officer had levelled the aircraft, the fluid in his ear canals keeps spinning to the right.
The aircraft is level but there's a very strong illusion from the ears that you're turning to the right.
He pushes the plane all the way to the left.
But why? - Level.
- I am! I am! The natural response would be to roll the aircraft back to where it came from into the 54-degree of bank, which was what they thought the level was.
And then he pulls it as hard as he can and the plane starts climbing.
This is a massive input.
The airplane would pitch up very quickly.
What's going on? He was completely baffled.
His vertigo may have led him to believe that the aircraft was pitching down.
So, he's actually recovering from an imaginary pitch-down.
He was disoriented.
With all the alarms that were going off, with the rapid left-right-left rolls and with the generally deteriorating situation, I think the crew had started to lose their spatial awareness completely.
Investigators finally understand what must have been going on with the first officer's confused state of mind.
But if the first officer wasn't operating the controls correctly, why didn't the captain take the one step that could have saved the lives of everyone on board? Investigators study the captain's behaviour during the roll.
Pull down! They know from the recordings that he was trying to help right the plane.
- Pull down.
- I'm trying.
It's not responding.
He wants his first officer to stop climbing up and push the nose down.
- Pull down! - But his command is confusing.
It's either you pull up or you push down.
When one thinks that the co-pilot is holding a side stick, pull means pull it back, which means go up.
And down means push it forward.
So pull down is a contradictory command.
In that case the captain should have said 'nose down, nose down.
' The first officer continues pulling back on his side stick until the very end.
- The input of the first officer - Pull down! - .
.
was the exact wrong thing to do.
- What's going on? He clearly didn't understand the command.
So why didn't the captain take full control of the airplane? He tried to take over here and over here.
- Pull! - It's not correcting.
There is a button on top of the side stick that can let you take full control to lock the other pilot out - Pull! - .
.
so that you know what's going on.
The data shows that the captain did push the take control button but only briefly.
He didn't push it long enough to take over the plane.
It's not responding.
But at the end he never took control.
It meant that both pilots were trying to fly at the same time.
If he'd spoken three simple words, the plane could have been saved.
The training is you say, "I have control" and the other pilot stops making inputs.
In this case, that wasn't happening.
Investigators now know that pilot error led to a spatially disoriented first officer.
The captain, who could have helped by communicating more clearly or taking over the plane, did neither.
Investigators can never be certain why.
The case is building to a close when they get another piece of information.
The results of the RTLU analysis are in.
It was a series of warnings from that unit that triggered the events that led to the crash.
(BLEEPING) ECAM actions.
The failure the crew had experienced with the rudder limiter system was actually a negligible failure.
It was a nuisance.
And the procedures to reset it - FAC 1 off and on.
- .
.
were simple.
FAC 2 off and on.
- Warning cleared.
- All the captain had to do was keep on following the ECAM's instructions.
The plane had had a history of RTLU failures throughout the year and this failure had never been fixed.
Microscopic examination of the unit's electronic module finally reveals the cause of those repetitive failures.
We found out that there was a crack in the soldering joint on the electronic module, which caused the RTLU to work from time to time only.
And had the correct maintenance task been applied Problem solved.
.
.
the RTLU electronic module would have been removed.
The airplane should have been sent for troubleshooting and you could have broken the chain of events.
For investigators, discovering that such a minute fault sparked events that led to the death of all 162 people on board, makes this all the more tragic.
As they prepare their final report, it's clear that the crash of Flight 8501 has exposed a series of serious problems.
The final report calls for improved maintenance protocols to help eliminate minor recurring problems, like the RTLU fault, before they lead to a major catastrophe.
When you start having four, five, six, eight, ten recurring problems, it's saying that the traditional methods are not working and that you need to do much more heavy duty diagnostics until they find the problem.
Pull! Pull down.
This is a case that the industry learned some very hard lessons, but the thing most importantly is that the industry implements those lessons so that we don't have another one.
Captioned by Ai Media ai-media.
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It crossed my mind "What could have caused it? Is it an act of terrorism, sabotage, something extreme happening to the aircraft?" For days, a massive search and rescue effort turns up nothing.
A crash at sea is challenging.
It's difficult to locate because you usually don't have the full flight path down to the surface of the ocean.
What they find paints a confounding picture of the final minutes of flight.
The plane started to bank.
We were very surprised by this action.
What are they doing? The investigation uncovers a single tragic misunderstanding that claimed the lives of 162 people.
NARRATOR: AirAsia Flight 8501, cruises high above the Java Sea north of Indonesia.
It's a few days after Christmas and many of the 156 passengers aboard the Airbus A320 are on holiday.
The pilot in command is 53-year-old Captain Iriyanto.
He's highly experienced with more than 20,000 hours in the air.
His first officer is French national Remi Emmanuel Plesel.
He is 46 with about 2000 flight hours, much of it on the Airbus.
On this particular leg, it was the first officer that was manipulating the controls.
The captain was in command of the flight but was performing the duties of the pilot monitoring, or the non-flying pilot.
Today's flight originated in the Indonesian city of Surabaya.
It's heading across the Java Sea to Singapore.
Total flight time is expected to be two hours.
- It looks like weather ahead.
- No.
I don't like the looks of that.
Twenty-two minutes into the flight, the pilots notice bad weather ahead on their radar.
Anti-ice? Anti-ice, on.
The crew would definitely be taking care to avoid penetrating these thunderstorms because it contains possibly extreme turbulence, hail, lightning, everything that the air crew don't want to expose themselves and the passengers to.
(PHONE RINGS) The captain instructs the flight attendant to prepare the cabin for turbulence.
Ladies and gentlemen, please return to your seats and fasten seatbelts.
Khairunnisa Haidar Fauzi is one of four flight attendants helping to look after the passengers as they cruise at 32,000 feet.
As an additional precaution, the captain decides to increase altitude, to go above the storm clouds in their path.
I'm gonna radio for a higher cruise, - get around that weather.
- Good idea.
But before the captain can contact air traffic control, he gets a fault warning from the flight computer.
ECAM actions? The plane's sophisticated computers give the pilots step-by-step instructions on how to fix the issue.
FAC 1 off and on.
FAC 2 off and on.
Warning cleared.
Computers control most of the Airbus A320's systems.
There are basically seven computers that fly the aircraft and they add a lot of helpful features that take workload away from the pilot.
Pilots are trained to follow the instructions given by the aircraft's computers.
(BEEPING) A few minutes later, the warning sounds again.
Same.
FAC 1 off and on.
After addressing the fault warning, the captain radios air-traffic control to request the higher flight level.
OK.
So Jakarta Air-Traffic Control, AirAsia 8501, request climb to 38,000.
The Jakarta air-traffic controller has had an uneventful night.
He soon clears the pilots to climb, but to a slightly lower altitude than the 38,000 feet requested.
AirAsia 8501, you are cleared to 3-4-0.
After permitting them to climb, the controller waits for confirmation But the pilots are distracted by a third alarm.
Here we go again.
- ECAM actions.
- FAC 1 off and on.
The controller hasn't heard back so he repeats his message.
AirAsia 8501, you are cleared to 3-4-0.
It's very annoying and very time consuming to deal with this recurring problem.
- Enough of this.
- ECAM actions.
The controller still hasn't heard confirmation from the pilots.
AirAsia 8501, do you read me? Please acknowledge.
But in the cockpit, the fault warnings have escalated.
AirAsia 8501, do you read me? Please acknowledge.
In the cabin, passengers have no idea their pilots are struggling to maintain control of the plane.
The pilots now notice that the plane is rolling sharply left.
Level.
OK.
Level.
Something is going terribly wrong with Flight 8501.
The first officer is struggling.
Level! But soon the plane is rolling again.
- Level! - I'm trying.
The pilots can't seem to regain control.
It's not responding.
AirAsia 8501, please confirm.
You are climbing to flight level 3-4-0.
The controller still hasn't heard confirmation from the pilots when the plane starts to climb towards 34,000 feet and then continues climbing steeply even higher.
No airline passenger would have ever experienced something like this under normal circumstances before.
It would have been a very violent, shocking manoeuvre.
- Pull down! - It's not correcting.
The plane seems to have taken on a life of its own.
It climbs higher and higher as the pilots fight to level off.
Then, inexplicably, the plane starts to drop.
That would certainly cause near panic in some people.
Other people would be waiting for the pilots to quote "fix it.
" - Altitude! - I see it! Flight 8501 is plummeting from the sky, speeding toward the ocean below.
The rate of descent here was very, very high.
It seems the pilots can do nothing to save their plane.
- Pull! - It's not correcting.
- What's going on? Max power.
- Slowly.
(SCREAMING) Forty-three minutes into what should have been a two-hour flight Eugh! .
.
AirAsia Flight 8501 disappears from radar.
- Pull! - I'm trying! - Pull! - It's not correcting! Eugh.
News quickly spreads of the mysterious disappearance of a commercial flight to Singapore.
The loss of AirAsia 8501 was a classic case of a flight degenerating from mundane, normal cruise conditions to the loss of the aircraft in a span of just 20 minutes.
Within hours, relatives of the 162 passengers and crew are demanding answers.
How could an airplane just disappear? All the authorities know is that the plane vanished from radar somewhere over the Java Sea.
Speculation runs wild about what could have brought the airliner down.
It crossed my mind "What could have caused it? Is it an act of terrorism, sabotage, something extreme happening to the aircraft?" But it was very difficult to come up with a clear picture on the first news reports as to what had taken place.
It's been only a few months since Malaysia Airlines flight 370, disappeared in eerily similar circumstances, vanishing from radar without sending any mayday call.
Search and rescue vessels are dispatched, but combing the vast and choppy sea between Sumatra and Borneo is a mammoth task.
An international team of air-safety investigators flies in to join the local experts in Jakarta.
Ray Nurcahyo is an air-crash investigator with the Indonesian National Transportation Safety Committee.
The air-traffic-control radar data is our main source to detect the location of the aircraft.
They begin by interviewing the air-traffic controller.
So can you tell me what happened? They were the ones who could tell us a little bit more about what had happened.
They had seen the plane trajectory, the plane flight path.
They learn that the plane was flying towards an area of bad weather.
When you start out in an investigation, you look at everything.
In this case, there were weather considerations.
And then? Then they started losing altitude fast.
And then it disappeared from radar at 24,000 feet.
Thank you very much.
How could this plane being in cruising altitude, suddenly climb and fall with a very high rate of descent? Could the aircraft have lost engine power in a violent storm? Can I get the weather overlay for this map, please? Investigators examine detailed weather charts from the day of the accident.
There were thunderstorms here and here.
It was monsoon season and so there's a lot of thunderstorms.
They can do damage to the airplane that It's something that you learn early as a pilot and it's something that you adhere to very strongly.
You do not fly through thunderstorms.
Then they start mapping the flight track to see if the plane - could have entered the storms.
- They were at cruising altitude.
Then here they asked for deviation.
They made it here and then they started to drop.
They almost flew into the first storm but then just missed it.
Bad weather, the first possible explanation for the disappearance of Flight 8501, proves to be a dead end.
This is the spot they were last seen on radar.
Based on Flight 8501's last radar coordinates, investigators have at least narrowed down the search area.
Dozens of rescue vessels and aircraft from multiple countries scour the target area.
A crash at sea is challenging.
It's difficult to locate because you usually don't have the full flight path down to the surface of the ocean.
The Indonesian President decides to address a nation in mourning.
Two days into the search, the first pieces of wreckage are recovered from the Karimata Strait in the Java Sea.
Soon searchers are finding bodies.
Among the first is that of flight attendant Khairunnisa Haidar Fauzi.
In a moving tribute, hundreds attend her funeral.
Funerals for many more follow.
Of the 162 passengers and crew, there are no survivors.
As the wreckage is brought in for examination, investigators can see that the task ahead of them is daunting.
Why would a highly sophisticated airliner, flying at cruising altitude, suddenly fall from the sky? We had a lot of little pieces everywhere.
My first reaction was, it's not gonna be easy.
Is it all like this? A crash at sea is challenging because usually the main interesting parts are underwater and that's a little bit difficult to get them.
With much of the plane still missing at the bottom of the sea, investigators study debris found floating on the surface.
To see if the plane exploded, they look for distinctive smaller pieces with burnt edges.
The debris that was recovered did not exhibit any tell-tale signs of having been subject to a bomb explosion.
This plane didn't blow up.
The pieces of AirAsia 8501 are large and clean.
We could eliminate a possible in-flight break up.
It's a step forward, but unless they can find the black boxes, the mystery of AirAsia Flight 8501 may never be solved.
The flight recorders offer the only hope of figuring out what was happening in the cockpit.
The search for them goes into high gear.
All black boxes are equipped with an electronic beacon that transmits a signal under water.
Ship-based sonar systems can detect the signal and help guide searchers towards the black boxes.
When we get this signal, we are in a range of about 2,000m from them.
So, this helps us narrow it down to where they are and then the divers then have to try to find them.
But weather complicates the search.
The depth was about 40 metres and the sea was rough.
And we couldn't go every day we wanted to go.
So, we had to adapt our strategy to the weather.
After a two-week search, they finally succeed.
We were relieved to get the boxes 'cause this was a real major step towards the explanation of what had happened.
Investigators start by listening to the cockpit voice recording.
It should reveal pilot conversations and other sounds from inside the cockpit of Flight 8501.
OK, let's start when they ask permission to climb.
Play recording.
Jakarta Air-Traffic Control, AirAsia 8501 request climb to 38,000 to clear storm clouds.
Up to that point the flight was normal.
It was uneventful.
Continue recording.
Almost immediately, investigators make a discovery.
- ECAM actions.
- FAC 1 off and on.
- FAC 2 off and on.
- (BLEEP) Warning cleared.
They were dealing with some kind of warning.
Play recording.
(BLEEPING) - ECAM actions? - Same.
OK.
The warning came back.
They were getting continual fault warnings through the what's called an ECAM system, Electronic Central Aircraft Monitoring System.
Play recording.
- Here we go again.
- ECAM actions.
FAC 1 off and on.
FAC 2 off and on.
- It's cleared.
- At this point, the crew's behaviour was standard, was normal.
They were quiet.
They were communicating on what checklists to apply.
AirAsia 8501, you are cleared to 3-4-0.
OK, stop.
We know from the controller that he never heard back from them again.
Play.
- (BLEEPING) - There it is again.
ECAM actions.
Then the recording reveals something surprising.
No.
I've got a better idea.
The captain appears to have done something different - and then there's a new warning.
- Hold recording.
Now the autopilot has disengaged.
An unexpected disengagement of the auto-throttle and auto-thrust system results in a pretty loud warning.
This is a very serious concern to the investigators.
RECORDING: (BLEEPING) - What was that? - OK, let's see what we have.
- Master caution? Why? - Checking (BLEEPING CONTINUES) (ALARM SOUNDS) .
.
level.
Level.
Investigators now hear yet another cockpit warning.
Stall warning.
The airplane would have warnings to tell the pilot that they were getting close to an aerodynamic stall.
Pull! Slowly! - What's going on? - Pull! NARRATOR: An aerodynamic stall occurs when the angle between the wings and the oncoming air gets too steep.
The amount of air flowing over the wings is reduced.
The aircraft loses lift and can no longer stay aloft.
It's a highly uncommon event to have an Airbus stall, particularly in cruise, because it's protected from stalling.
Normally the computer won't allow the aircraft to stall.
It won't allow the wings to go at too high an angle to the airflow and stall the aircraft.
NARRATOR: What caused this technically advanced plane to stall? The autopilot disconnects.
The aircraft stalls.
They struggle to recover.
It makes no sense.
Only the FDR data can reveal what was happening with the aircraft the moment the crisis hit.
Until that data is ready for analysis, the deadly mid-air stall remains a mystery.
What were you guys struggling with? One of the questions that the investigators would have faced is why and how did an aircraft that is supposed to be stall proof end up stalling?" Pull down.
Slowly! The flight data recorder should provide answers, but it needs to be flushed of salt water before it can be read.
In the meantime, investigators pull the plane's maintenance records to look for clues.
They soon make a discovery.
The aircraft seems to have an issue with its RTLU.
RTLU is the Rudder Travel Limit Unit.
The plane had had a history of RTLU failures.
The Rudder Travel Limit Unit is a computerised component that prevents the rudder on the tail from deflecting too far in either direction when the plane is travelling at high speed.
If the flight computer detects any problems with its rudder limiter, it sends a warning to the cockpit.
Records show the aircraft's Rudder Travel Limit Unit had been malfunctioning for almost a year.
Twenty-three reports of the exact same failure.
The RTLU failures on this particular airframe had become increasingly frequent.
There were 11 in the last couple of months and 23 in the preceding period, which is highly unusual.
That seems like a lot of failures with the RTLU.
Could these be connected to the mystery warnings the pilots were experiencing? It could be a major breakthrough.
Three days before the crash there were two exact same failures.
Why was this happening? After each failure, maintenance workers reset the RTLU.
TRANSLATION : As long as the reset resulted in the computer to prompt pass, maintenance personnel doesn't have to investigate further.
They just kept resetting it and then putting it back in service.
But they never found a permanent fix.
They were returning the airplane to service after reset and from a legal standpoint it did clear the problem.
But obviously, whatever the fault was they hadn't found it because the problem continued to reoccur.
The aircraft seemed to operate perfectly despite the warnings.
Even the day before the crash, the plane had successfully flown from Surabaya to Kuala Lumpur.
Have we got the unit? The plane's RTLU is among the wreckage that's been recovered from the Java Sea.
Let's send it back to the manufacturer and see if they can find something.
The unit is sent to France for analysis.
Finally, investigators get to examine a key piece of evidence, the flight data recorder.
If they can download all the flight data, it should provide a detailed picture of exactly what was happening with the electrical and mechanical control systems on the aircraft.
We worked with the Indonesian Investigation Authority in extracting the data, which requires a lot of precautions since the flight recorders had been immersed.
Move it down too, a little bit.
On examination, they discover the data board has been damaged by the impact of the crash.
It's uncertain whether the information they desperately need will be retrievable.
The download begins.
Even though the condition of the black box was damaged, we managed to recover all of the data.
Success.
"OK, so let's start with those chime warnings.
OK.
So here's the first warning.
It clearly was the RTLU.
They do the fix, simply resetting the entire system.
The procedure to reset the system was much like your PC, rebooting the PC.
They only had to turn the system off and turn it back on again.
FAC 2 off and on.
Two more times the RTLU warning goes off and each time they did the right thing.
Then it went off on a fourth time.
Then suddenly there was a glitch.
What did they do different? After the fourth time, the warnings change.
There is now a fault with the aircraft's two main computers, known as the flight augmentation computers.
Put the new data up on that screen.
Something caused both computers to fail at the same time.
But nothing in the data shows what the crew did differently after the last warning.
What does come to light, is that when the autopilot disengaged the rudder moved slightly.
Now let's see.
The plane started to bank to the left.
The electrical interruption on the flight control computers created a rudder movement of about two degrees to the left.
Two degrees does not sound like a lot, but at the speed they were flying, it's exactly what caused them to roll left 54 degrees.
That's almost twice the normal bank that you would feel in an airliner.
Now look at this.
It took them nine seconds to do anything about the bank.
Despite the steep bank angle, it seems the crew was slow to react and level the plane.
During the first nine seconds, there was no crew inputs on the controls following this roll that reached 54 degrees.
Then the first officer suddenly reacts, pulling hard to the right, then left again and just as suddenly he starts to pull up.
All they had to do was steady the plane.
What were they doing? The FDR data shows that the plane climbed steeper and steeper until they reach a remarkable 45-degree pitch up.
Then it stalled.
Investigators know that the captain did something different, something that led to a computer glitch causing the autopilot to disconnect and the plane to bank sharply.
But they don't know what he did.
The single event of autopilot, autothrottle disengagement sends the investigators in two different directions.
One, what caused it? Two, how did the crew handle it? As investigators struggle to answer puzzling questions about Flight 8501 and its crew (PHONE RINGS) Hello? NTSC.
.
.
they get an important new lead.
Wait, wait.
Slow down.
What happened? A mysterious action by the captain to solve a routine error, appears to have set off a deadly sequence of events.
Investigators are still trying to understand what happened when they receive some new information.
Start from the beginning.
Where was he? Three days before the accident, on December 25, this same captain was about to fly from Indonesia to Kuala Lumpur when he had an RTLU malfunction.
He asked for an engineer to come to the cockpit and try to fix that.
- RTLU problem again? - Yeah, it just keeps coming back.
The maintenance engineer rebooted the system - There.
- Ah (BLEEPING) .
.
but the problem came back.
I've got an idea.
He then pulled the circuit breakers for the main computer.
Maintenance on the ground has a very specific list of circuit breakers that says you can utilise pulling these circuit breakers to reset computers within the airplane.
As the captain watched, the problem was fixed.
- (BLEEP) - Problem solved.
And can I do the same thing if it happens again? Yeah, just do what the ECAM tells you to do.
Don't tell me he tried to do that in the air.
Investigators think that they now know what the captain did that led to the crisis in the cockpit.
Begin simulation.
To see if they're right, they decide to simulate the cockpit warnings heard in flight.
OK, so let's start with the RTLU warnings.
(BLEEPING) FAC 1 off.
FAC 2 off.
Good.
(BLEEPING) Enough of this.
After the fourth RTLU warning, he takes a new approach.
- ECAM actions? - No.
I've got a better idea.
Investigators believe the captain pulled two critical circuit breakers.
Captain pulls circuit breaker one.
The result is immediate.
And there goes the autopilot disconnect warning.
Investigators can now be certain of one thing.
This had to be what he did.
He was perhaps copying what he'd seen the ground engineer do but of course the consequences in flight to disabling critical systems are quite different.
The captain wrongly assumed that if it worked on the ground, it'll work in flight.
TRANSLATION: The circuit breaker, which is part of the flight augmentation computer, is something that should never be pulled out in the air.
Pulling the circuit breakers has devastating consequences the captain didn't anticipate.
Unfortunately, he was not pulling circuit breakers that affected only the rudder limiter system but ones that also disabled the flight augmentation computer, which tripped the autopilot, the autothrottle and all the normal mode protections that the aircraft had.
The plane begins to roll.
Over the next nine seconds, it rolls 54 degrees, yet no-one does anything to stop it.
What took them so long to react? The first officer would have been looking here and here when the autopilot warning was disconnected and the captain was still standing behind the first officer's seat.
What was that? It's likely that neither pilot was looking at the attitude indicator that showed the plane was banking.
That's why it took them nine seconds to notice what this gauge here was telling them.
As the plane started to roll, the first officer was focused on the fault warnings.
He didn't notice that the plane was banking until the captain sat back down again.
- Oh, my god.
- Oh! Despite losing control of these systems, the high-tech plane did have the capacity to get back on course.
After the initial roll, why didn't the first officer just steady the plane and re-engage the autopilot? Investigators have to try to understand what was going on inside the pilots' heads.
The co-pilot's movement of the stick to its extreme right-most position, resulted in a very violent roll to the right, two to three times what would be programmed as the maximum for an Airbus normally.
In an attempt to understand the first officer's actions, investigators study how the human brain behaves in flight.
A sense of balance is maintained by liquid levels in the ear canals.
When that shifts violently, the brain can get mixed signals that affect balance.
The FDR data shows how dramatic the plane's movements were.
So the plane rolled 54 degrees left and he pulled back almost level in just two seconds.
That would scramble anybody's gyros.
Maybe that was the confusion? As soon as the first officer had levelled the aircraft, the fluid in his ear canals keeps spinning to the right.
The aircraft is level but there's a very strong illusion from the ears that you're turning to the right.
He pushes the plane all the way to the left.
But why? - Level.
- I am! I am! The natural response would be to roll the aircraft back to where it came from into the 54-degree of bank, which was what they thought the level was.
And then he pulls it as hard as he can and the plane starts climbing.
This is a massive input.
The airplane would pitch up very quickly.
What's going on? He was completely baffled.
His vertigo may have led him to believe that the aircraft was pitching down.
So, he's actually recovering from an imaginary pitch-down.
He was disoriented.
With all the alarms that were going off, with the rapid left-right-left rolls and with the generally deteriorating situation, I think the crew had started to lose their spatial awareness completely.
Investigators finally understand what must have been going on with the first officer's confused state of mind.
But if the first officer wasn't operating the controls correctly, why didn't the captain take the one step that could have saved the lives of everyone on board? Investigators study the captain's behaviour during the roll.
Pull down! They know from the recordings that he was trying to help right the plane.
- Pull down.
- I'm trying.
It's not responding.
He wants his first officer to stop climbing up and push the nose down.
- Pull down! - But his command is confusing.
It's either you pull up or you push down.
When one thinks that the co-pilot is holding a side stick, pull means pull it back, which means go up.
And down means push it forward.
So pull down is a contradictory command.
In that case the captain should have said 'nose down, nose down.
' The first officer continues pulling back on his side stick until the very end.
- The input of the first officer - Pull down! - .
.
was the exact wrong thing to do.
- What's going on? He clearly didn't understand the command.
So why didn't the captain take full control of the airplane? He tried to take over here and over here.
- Pull! - It's not correcting.
There is a button on top of the side stick that can let you take full control to lock the other pilot out - Pull! - .
.
so that you know what's going on.
The data shows that the captain did push the take control button but only briefly.
He didn't push it long enough to take over the plane.
It's not responding.
But at the end he never took control.
It meant that both pilots were trying to fly at the same time.
If he'd spoken three simple words, the plane could have been saved.
The training is you say, "I have control" and the other pilot stops making inputs.
In this case, that wasn't happening.
Investigators now know that pilot error led to a spatially disoriented first officer.
The captain, who could have helped by communicating more clearly or taking over the plane, did neither.
Investigators can never be certain why.
The case is building to a close when they get another piece of information.
The results of the RTLU analysis are in.
It was a series of warnings from that unit that triggered the events that led to the crash.
(BLEEPING) ECAM actions.
The failure the crew had experienced with the rudder limiter system was actually a negligible failure.
It was a nuisance.
And the procedures to reset it - FAC 1 off and on.
- .
.
were simple.
FAC 2 off and on.
- Warning cleared.
- All the captain had to do was keep on following the ECAM's instructions.
The plane had had a history of RTLU failures throughout the year and this failure had never been fixed.
Microscopic examination of the unit's electronic module finally reveals the cause of those repetitive failures.
We found out that there was a crack in the soldering joint on the electronic module, which caused the RTLU to work from time to time only.
And had the correct maintenance task been applied Problem solved.
.
.
the RTLU electronic module would have been removed.
The airplane should have been sent for troubleshooting and you could have broken the chain of events.
For investigators, discovering that such a minute fault sparked events that led to the death of all 162 people on board, makes this all the more tragic.
As they prepare their final report, it's clear that the crash of Flight 8501 has exposed a series of serious problems.
The final report calls for improved maintenance protocols to help eliminate minor recurring problems, like the RTLU fault, before they lead to a major catastrophe.
When you start having four, five, six, eight, ten recurring problems, it's saying that the traditional methods are not working and that you need to do much more heavy duty diagnostics until they find the problem.
Pull! Pull down.
This is a case that the industry learned some very hard lessons, but the thing most importantly is that the industry implements those lessons so that we don't have another one.
Captioned by Ai Media ai-media.
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