Mayday (2013) s18e09 Episode Script

Deadly Go-Round

Lead Investigator: Start the playback, please.
A routine landing in Nagoya, Japan Captain Chi: The more you fly, the better you'll get.
quickly turns to chaos in the cockpit.
First Officer Meng-Jung: Sir, I still cannot push it down.
Captain Chi: Push down more.
Lead Investigator: That's crazy.
Captain Chi: What's the matter with this? John Wyman: That's high drama when a pilot pushes forward on a control column and he says, what's the matter with this? That's something seriously wrong.
Captain Chi: It's over! Ahhhh! Ron Schleede: It's a catastrophic accident with over 200 people.
What caused two pilots to lose control of their plane in mere seconds? Ron Schleede: I don't think either one of these pilots really understood what this was.
Captain Chi: Nagoya approach, Dynasty 1-4-0, now approaching ten thousand six hundred.
Eight o'clock on a Tuesday evening.
China Airlines flight 140 is headed for Japan's Nagoya Airport.
Air Traffic Controller: Dynasty 1-4-0, descend and maintain six thousand.
Captain Chi: Descend six thousand.
The crew is nearing the end of a two-and-a-half hour flight from Taipei.
There are 256 passengers in the cabin.
Most are returning from package tours of Taiwan.
Makoto Habuka: I'm glad you enjoyed the trip.
I hope we can organize another one soon.
Makoto Habuka is a Japanese businessman returning home after taking a group of 20 people on a tour of fabric shops in Taipei.
Wataru Habuka: My brother created his own kimono company and was growing the business.
He organized a tour for long-time customers.
The plane is the newest version of the popular Airbus A300.
The A300 is a pioneer of the industry's push towards fully automated aircraft.
Shawn Pruchnicki: The A300 was a significant change.
This airplane came out at a time where technology was just literally exploding.
Shawn Pruchnicki: This level of automation now allowed us to fly the airplane far more precise than we've ever been able to do before.
Instead of three, four or five pilots in a cockpit, planes like the A300 now have just two.
Computers are seen as a cheaper, safer alternative to all that manpower.
Shawn Pruchnicki: The autopilot maintains a very precise control of the aircraft, and that allows the pilot to be more in a supervisory mode, to take the bigger picture in rather than focusing on the very small movements of flying the airplane.
It was thought that this would solve all of our human error problems.
It would dramatically decrease the accident rate.
Flight 140's scheduled flight path takes it from Taipei over the East China Sea to Nagoya, Japan.
Captain Chi: Ladies and gentlemen, this is your captain.
We'll be landing in Nagoya in about 15 minutes.
We should have you at the gate by 8:30.
Makoto Habuka: Good.
It looks like we're gonna be on time.
Captain Chi: Shoulder harness.
Approach checklist complete.
Do it by yourself.
I won't bother you.
Don't ask me.
Do it yourself.
The first officer is twenty-six-year-old Chuang Meng-Jung.
He's flying the plane under the watchful eye of his captain.
Captain Chi: Okay? Wang-Lo Chi has more than 20 years' experience flying military aircraft, 747 passenger jets, and now the Airbus.
Ron Schleede: It wasn't uncommon that you would pair a, a senior captain with a less experienced co-pilot so he can provide some training and guidance to him.
As the plane approaches the airport, light turbulence shakes the cabin.
Air Traffic Controller: Dynasty 1-4-0, reduce speed 1-8-0 knots.
The air traffic controller advises flight 140 to slow down.
It's getting too close to a larger plane ahead.
The Airbus is being buffeted by wake turbulence.
But the captain isn't worried.
John Wyman: It's common enough.
Normally after you pass through the wake turbulence you can recover the airplane all right.
Captain Chi: Make sure you step firmly on the rudders.
It'll be okay.
It won't sway so much.
Better reduce the speed a little more.
Reduce it to 170.
Air Traffic Controller: That's better.
Captain Chi: Okay.
Fly manual.
They'll be landing tonight without the use of the autopilot.
Ron Schleede: If they use the autopilot all the time they'd lose their skills to fly manually, so it wouldn't be unusual for the captain to elect to fly the approach manually to give the co-pilot experience.
First Officer Meng-Jung: Gear down.
Captain Chi: Gear down.
Flaps 40.
Spoilers armed.
Landing lights on.
They're less than three minutes to touchdown.
Air Traffic Controller: Dynasty 1-4-0, cleared to land runway three-four.
Captain Chi: Cleared to land runway three-four.
The plane gains an unexpected burst of speed.
Passengers can sense a change.
They're no longer descending.
Just when the plane should be slowing for landing, the engines are surging.
John Wyman: If the power comes on you're going to destabilize the approach.
That's what's gonna happen.
The plane is now leveling off instead of descending towards the runway.
Captain Chi: Push it down.
The first officer tries to lower the nose.
Captain Chi: Push it down! Pushing the control column seems to have no effect.
They need to get back on course for landing.
Captain Chi: Disengage throttle.
Captain Wang wants his First Officer to reduce power.
If they don't get back on the proper descent path, they could overshoot the runway.
John Wyman: You're going to want to take that power off.
If you're too high and too close to the runway you're gonna land halfway down the runway and that could potentially be a bigger problem.
Airspeed has slowed, but the plane still isn't responding to the pilot's nose down command.
Captain Chi: Push more.
Push down more.
With reduced power, the plane is now quickly losing speed and altitude.
They're barely three hundred feet from the ground.
First Officer Meng-Jung: Sir, I still cannot push it down.
Captain Chi: Okay.
I've got it.
I've got it.
The captain takes over.
But he also struggles to control the plane.
Captain Chi: What's the matter with this? The pilots decide to abandon the landing.
Captain Chi: Go around.
First Officer Meng-Jung: Nagoya tower, Dynasty going around.
A surge of thrust kicks in as the captain advances the throttles to climb out.
John Wyman: When something becomes too destabilized, too close to the ground, well that's when a go around should be called.
Air Traffic Controller: Roger, stand by for further instructions.
The controller must now find a clear route for flight 140 to circle around and try their landing again.
But the go around procedure isn't working.
The plane is now climbing much too steeply.
Captain Chi: If this goes on, it will stall.
The angle is so steep the plane can no longer stay airborne.
Captain Chi: It's over! Wataru Habuka: I was in Tokyo and took a taxi.
I heard something on the radio.
An airplane crashed in Nagoya.
I felt maybe my brother might be on the plane.
So I got out of the taxi quickly and called my house from a payphone.
I asked to check the news on TV and it was already showing fire on the screen.
I finally got through to his house in Nagoya.
His child answered the phone and I asked, was your father on the airplane? And he said he was.
Rescue crews are on site in minutes.
They battle flames three stories high.
It takes more than an hour to contain the raging fire.
Ron Schleede: It's a catastrophic accident with over 200 people.
They'd probably never seen an accident like this.
Newscaster: Good evening.
In Nagoya, Japan, which is west of Tokyo, it was early evening when a China Airlines flight from Taiwan approached for a landing.
Suddenly it tried to take off again but the engines exploded and the Airbus crashed.
Incredibly, seven people survive the disaster, including a six-year-old boy and his three-year-old brother.
Shigeru Saito: It was a miracle that seven people survived in the end.
But 264 people are dead, including the crew.
Makota Habuka dies in the crash.
He leaves behind a wife and three young children.
Wataru Habuka: I was hoping he was still alive.
Around 11 pm, it showed his name on the screen.
Then I knew it clearly.
We were so upset.
It is the second deadliest plane crash in Japanese history and China Airlines' worst accident ever.
Wataru Habuka: We wanted to know the cause of the accident.
The next morning, investigators from Japan's Aircraft Accident Investigation Commission survey the devastation.
The Airbus is completely destroyed, shattered into thousands of scorched pieces.
They have no idea why, and everyone wants answers.
Lead Investigator: Make sure you get shots of everything.
Investigators hope the debris field can help them piece together what happened.
Nagakatsu Kawahata is working with the Aircraft Accident Investigation Commission.
Nagakatsu Kawahata: The scattered parts give us hints about the accident.
For example, if metal parts were worn out and had disintegrated in the air we would see the evidence of that.
Lead Investigator: They didn't miss by much.
Investigator: Approximately 360 feet east from the runway.
The plane crashed just to the side of the airport's one runway.
Why would a sophisticated aircraft with an experienced captain end up here? Ron Schleede: You don't want another airplane going down for the same reason.
So you would have urgent need to determine what's wrong with this airplane, if there is something wrong with it.
Lead Investigator: Impact scars.
The soft earth by the runway offers clues.
Investigators find a series of scars where the plane hit the ground.
Lead Investigator: This one's much deeper.
Investigator: It looks like left-side landing gear.
The evidence paints a picture of how the plane came down, at a four-degree nose up angle and leaning to the left.
The landing gear hit first, then the left and right engines.
The wings were ripped from the fuselage, rupturing the fuel tanks.
Ron Schleede: This was a relatively short wreckage path, indicating that the airplane did not have a lot of forward motion.
It was coming down vertically more than forward and so it pancaked into the ground.
The question now is why was the plane coming in at such a sharp angle? Lead Investigator: You mind if I record our conversation? Air Traffic Controller: Go right ahead.
Investigators hope the air traffic controller has some answers.
Lead Investigator: Any idea why the plane missed the runway? Air Traffic Controller: None.
They got a bit close to another plane on approach, but I slowed them down.
Captain Chi: Reducing one-eight-zero knots.
Air Traffic Controller: A few minutes later, I cleared them to land, and they copied that.
Captain Chi: Cleared to land runway three-four.
Air Traffic Controller: And I heard nothing until they said they were going around.
Lead Investigator: How'd the pilot sound when he radioed for the Go Around? Air Traffic Controller: A little rushed, but not panicked.
Lead Investigator: And he didn't say why? Air Traffic Controller: No.
A Go Around isn't considered an emergency situation.
First Officer Meng-Jung: Nagoya Tower, Dynasty going around.
It's used to avoid one.
John Wyman: Go Around mode is a series of commands sent from the flight management system that will apply the climb thrust required to bring it up to a safe altitude after an approach has been aborted.
Air Traffic Controller: Roger.
Standby for further instructions.
The controller acknowledged the Go Around procedure.
But just moments later, the Airbus hit the ground.
Air Traffic Controller: I didn't hear from them again.
It was all so fast.
The interview only deepens the mystery.
Lead Investigator: Thank you.
I'll let you know if I have any other questions.
Investigators still don't know why the crew called for a Go Around, or why it went so wrong.
Pressure to find answers is mounting.
Mourning Taiwanese family members are flown in to identify the bodies.
The enormity of the disaster is sinking in.
Recovered travel documents help Wataru Habuka identify his brother, Makoto.
Makoto Habuka: I hope we can organize another one soon.
Thank you.
Wataru Habuka: His passport was in here.
They found it after the fire was extinguished.
So that's why they could identify him by name.
Lead Investigator: Put it this way, guys.
Investigators face a massive puzzle.
They must identify and catalogue hundreds of pieces of wreckage, any one of which could hold valuable clues.
Lead Investigator: This way.
The black boxes could help.
Both the cockpit voice recorder and the flight data recorder have been recovered.
Nagakatsu Kawahata: Without it, it would be extremely difficult to find the cause of the accident.
But it could be weeks before anyone knows Investigators know that flight 140 fell from the sky at an extremely steep angle.
They wonder if it had a problem with engine thrust.
Lead Investigator: Pratt and Whitney engine, model 4-1-5-8.
Could the three-year-old plane somehow have suffered catastrophic engine failure? Nagakatsu Kawahata: If the engines stop working, the plane will start to fall.
Ron Schleede: We're looking to see were they running? Were they operating properly at the time of the crash? They examine the engine core Lead Investigator: Let's see what we got.
.
.
looking for signs of mid-air engine flameout.
Lead Investigator: There seems to be only exterior fire damage.
They do find scorching consistent with an engine power surge, but nothing that points to an internal explosion or fire.
Ron Schleede: If it gets into a very bad attitude, very high nose high attitude, very slow airspeed, the engines can, can pressure stall.
They surge.
And you can actually get flames out of the back and front of the engines if they're in this surging mode.
With an engine fire ruled out, investigators look to see if anything else could have caused the power plants to cut out in flight.
Lead Investigator: These blades are in bad shape.
The engine fan blades provide an important clue.
Investigator: Look at all this rotational damage.
The way the blades are damaged indicates they were spinning when they hit the ground.
Nagakatsu Kawahata: Engine output looked normal.
We didn't believe the engines malfunctioned.
First Officer Meng-Jung: Nagoya tower, Dynasty going around.
The question now: If the engines had enough power to go around, why did the maneuver fail? Captain Chi: Damn it.
Investigators have another suspect - the Airbus's wing surfaces.
Movable slats and flaps are built into the front and rear edges of the wings.
Their position must be adjusted according to the plane's speed.
Ron Schleede: Flaps and slats are aerodynamic devices that help the airplane fly at slower speeds for takeoff and landing.
It's very important that the flaps operate properly.
If the pilots forgot to change the flap settings for the Go Around, the plane may have suffered from too much drag.
Captain Chi: If this goes on, it will stall.
The wings were badly damaged in the crash, some of the flaps ripped right off.
But that doesn't throw investigators off course.
They should be able to determine flap settings by examining other parts inside the wing, parts known as jackscrews.
Lead Investigator: These should tell us.
The jackscrew spins on a nut, in one direction to extend the flaps, in the other to retract them.
Investigators measure the distance to the nut to see what position the flaps were set at.
Lead Investigator: Looks like fifteen degrees.
Is that right? Investigator: According to the manual, yes, that's the correct setting.
Lead Investigator: So the plane should have had plenty of lift.
The flaps and slats were exactly where they needed to be for a Go Around.
Why the Airbus and 271 people plunged to the ground is still a mystery.
Japanese investigators call on Airbus for help.
Lead Investigator: Thanks for coming.
The French manufacturer sends a technical expert who knows the A300 inside and out.
Ron Schleede: France is the state of design, the state of manufacture.
They have an obligation to determine if there's airworthiness problems and to correct them on the fleet worldwide.
Lead Investigator: I've been examining these instruments, but I'd like to get your take.
Confident that the plane's engines and wing flaps were not factors in the crash, investigators turn their attention to the cockpit instruments.
Ron Schleede: In any accident investigation, you want to document the cockpit, document the position of switches, any indicators that might show what the position was at impact.
They focus on the thrust levers.
First Officer Meng-Jung: Nagoya tower, Dynasty going around.
Were the thrust levers in the right position to provide enough power for a Go Around? Airbus Expert: Forward position, right where you want it.
To investigators, it looks like they were.
And it matches what the controller told them about flight 140 requesting a Go Around.
Air Traffic Controller: Roger.
Standby for further instructions.
Lead Investigator: So the flight computer would have kicked in for the Go Around mode.
Airbus Expert: Mm-hmm.
What investigators have uncovered so far is puzzling.
It appears the plane was properly configured to perform a flawless Go Around.
Lead Investigator: The flaps and slats were set.
The engines were at full power.
Everything was where it needed to be.
So what went wrong? To understand the fatal crash of flight 140, investigators first need to figure out why the Air China pilots aborted their landing just moments from the runway.
Lead Investigator: Are we ready? They now have an important tool to help them.
In 1994, the digital flight data recorder is relatively new.
Ron Schleede: The digital recorders were a real boon to accident investigation compared to the old foil recorders, 'cause the foil recorders only had five parameters.
Digital recorders recorded a lot more information, and a lot of it was more accurate.
Lead Investigator: Let's isolate the data streams.
Maybe we can spot an anomaly.
Nagakatsu Kawahata: Over 100 different kinds of information are recorded on it.
Utilizing all that information, we could recreate the flight conditions.
The data should reveal if there was an onboard system malfunction or any alarm warning that landing would be unsafe.
Lead Investigator: This is a timeline of the airspeed.
Investigators can see that the speed drops on the initial approach when the Air China crew is dealing with wake turbulence.
Captain Chi: Better reduce the speed a little more.
Reduce it to 170.
But the speed only drops slightly.
Airbus Expert: Speed is still good for an approach.
Nothing to worry about.
Lead Investigator: Mm-hmm.
The turbulence didn't prompt the pilots to go around.
The buffeting stopped in plenty of time for a safe landing.
As flight 140 descends towards one thousand feet, everything looks normal.
Lead Investigator: They activate the Go Around mode right here.
I don't get it.
Why would they do that? Everything seems fine.
There's nothing in the data that seems to warrant a Go Around.
Go Around mode kicks the auto throttle into high gear with a burst of power meant to lift the plane quickly.
John Wyman: It's a surge of power that comes on quickly.
The attitude of the aircraft changes to put its nose above the horizon and, yeah, you get put back in your seat pretty quick.
Lead Investigator: So the plane is responding as it should, except here.
The data indicates the first officer is fighting the Go Around mode.
He's pushing on his control column to try to pitch the plane downwards.
Shigeru Saito: There was a conflicting operation between the computer and the pilots.
Captain Chi: Push it down.
Ron Schleede: That indicates an unstabilized approach.
This crew was having trouble.
Airbus Expert: The plane can handle the Go Around by itself.
Lead Investigator: Exactly.
But it seems they're fighting against the automated systems.
It's a startling finding.
Nagakatsu Kawahata: The FDR showed us abnormal actions.
We didn't understand why the pilots were doing them.
The black box data leads investigators to turn a spotlight on the pilots themselves.
Lead Investigator: What were these guys thinking? Digging into their personnel files, they learn that the first officer joined China Airlines as a student, training on small aircraft before working up to the A300.
He made first officer just a year before the crash.
Captain Chi: Okay? John Wyman: The FO was essentially trained in a university.
He did 590 hours on, you know, a variety of smaller twin-engine airplanes all in a training environment.
And now he's with a major airline in the right seat of a very large airplane.
So that's pretty startling in itself.
The China Airlines practice is for new pilots to keep learning on the job with an experienced captain at their side.
Lead Investigator: Captain Wang Lo-Chi, 42 years old.
Captain Wang should have been up to the task.
He had more than 8,000 flight hours over a 24-year career.
But when investigators drill down, it's not so clear-cut.
Lead Investigator: Not a lot of time in the Airbus.
They learn that the captain flew Boeing 747s for most of his time at China Airlines and just as a first officer.
He was only promoted to captain a year ago when he started flying the A300.
He was as new to the plane as his first officer with just over 1300 flight hours.
John Wyman: So you have a captain that's come from an older generation of airplanes, and you have a first officer that's come from a newer generation of airplanes but only from a school background.
So that's two relatively new pilots on the same airplane.
By 1994, there were hundreds of A300s in the skies.
Airlines needed trained pilots to fly these technologically advanced aircraft.
The crew on the accident flight was part of this surge.
Captain Chi: It's okay.
Just do it slowly.
Did the pilots understand the flight systems well enough? Only the voice recorder can provide answers.
Captain Chi: Aaaahhhh! After weeks of work, investigators are ready to listen to the cockpit voice recording from China Airlines flight 140.
Lead Investigator: Start the CVR playback, please.
Did the pilots say anything that might explain the fatal crash? Captain Chi: The more you fly and practice, the better you'll get.
Lead Investigator: That must be the captain.
Almost 8 pm at about 10,000 feet.
First Officer Meng-Jung: Yes, I see.
Lead Investigator: That'd be the first officer.
He sounds nervous.
Captain Chi: Just put them down gently, like this.
Just fly like this.
It's clear the captain is very much in charge.
Captain Chi: Throttle like this.
Do it by yourself.
I won't bother you.
Don't ask me.
The captain speaks to his first officer as if he's never been in a cockpit before.
Captain Chi: Okay? Meanwhile, 256 passengers are along for the training session.
Nagakatsu Kawahata: The communication between the pilots is very poor.
It sounds all one-sided.
Captain Chi: Make sure you step firmly on the rudders.
Nagakatsu Kawahata: The captain has absolute power in the cockpit.
The co-pilot can't say a thing.
Captain Chi: It'll be okay.
It won't sway so much.
The teacher/student relationship works well through the wake turbulence.
Captain Chi: Okay, fly manual.
And as the first officer switches to manual flight Lead Investigator: He disengages autopilot here at about 2300 feet.
The landing approach is right on track.
Then they hear something completely unexpected.
Captain Chi: You triggered the Go lever.
First Officer Meng-Jung: Yes, I, uh, I touched it a little.
Captain Chi: Disengage it.
Lead Investigator: Stop playback.
He hit the Go Around by mistake.
It's a major discovery.
Until now, investigators had assumed the crew intended to do a Go Around.
Now it appears the young first officer engaged Go Around mode by accident.
Investigators suspect that the first officer's hand touched the small Go Around switch on the front of the thrust levers.
Shigeru Saito: The cause is unclear.
Certainly he touched it.
The data showed it.
Along with a boost in thrust, Go Around mode activates the plane's horizontal stabilizer.
The stabilizer is the horizontal section of the plane's tail.
It pivots up and down to help control the plane's pitch.
In Go Around mode, the computer moves the stabilizer to send the plane nose up.
Lead Investigator: Continue, please.
Captain Chi: Push down.
Push more.
Push down more.
What investigators are hearing is stunning.
The crew has plenty of time to turn off the Go Around mode, but for some reason don't.
Instead, the pilots plow ahead and attempt to land.
Lead Investigator: That's crazy.
The aircraft is now caught between two opposing commands.
The first officer is trying to push the nose down, but the flight computer is commanding the horizontal stabilizer to go nose up.
First Officer Meng-Jung: Sir, I still cannot push it down.
Shigeru Saito: The aircraft system was trying to go up, but both pilots were trying to land instead.
They thought it would work if they pushed on the control column.
Shawn Pruchnick: They were simply fighting the automation all the way down to the ground and not realizing it.
Lead Investigator: So it's computer versus pilot.
Airbus Expert: The computer will win every time.
It overrides the manual command.
Shigeru Saito: The main cause of this accident was that they didn't understand the movement of the horizontal stabilizer.
So the input from the computer wins.
Captain Chi: Disengage throttle.
The plane is now dropping at a thousand feet per minute.
Captain Chi: Push down.
Push more.
But the captain keeps telling his young co-pilot to land.
Lead Investigator: The captain should have taken over immediately.
Ron Schleede: The captain didn't take over and take charge.
He tried to salvage the approach trying to help the co-pilot continue.
Captain Chi: Push down more.
Ron Schleede: Once the airplane is below a thousand feet, everything's gotta be perfect.
If it isn't perfect, get the airplane up and get out of there.
Captain Chi: Okay, I've got it.
He takes the controls just 40 seconds before impact.
Captain Chi: What's wrong with this? Damn it, why is it like this? Lead Investigator: It sounds like he thought it was an easy problem to fix.
John Wyman: I mean that's high drama when a pilot pushes forward on a control column and he says, what's the matter with this? That's something seriously wrong.
Somehow, in their panic, both pilots failed to notice that the plane is still in Go Around mode.
Shawn Pruchnicki: The cues that could have told them what the automation was doing were extremely obscure.
There was a small indication on a screen, very difficult to see those, especially in a whole sea of information.
It's very much a data overload situation with extremely small time constraints.
Captain Chi: Go Around.
First Officer Meng-Jung: Nagoya tower, Dynasty going around.
The captain decides to execute a manual Go Around.
But it's too late.
Adding thrust only sends the nose up faster.
Lead Investigator: All that sudden thrust pushes them 50 degrees nose up in just seconds.
Captain Chi: If this goes on, it will stall.
Ron Schleede: They got it in such a bad configuration the airplane stalled.
And when it stalls it's gonna go down very fast.
Captain Chi: It's over! Aaahhh! Shigeru Saito: It was very shocking when I heard these voices.
Both pilots were trying to recover.
I think the voices showed all hope was lost.
Lead Investigator: Why didn't the pilots know the computer was gonna take over? It's the last question facing investigators.
To answer it, they'll need to explore the complexities of computer automation and the limits of human understanding.
Captain Chi: Push down more.
How could two trained pilots have such a flawed understanding of their plane's computerized flight systems? First Officer Meng-Jung: Sir, I still cannot push it down.
Captain Chi: Okay, I've got it.
I've got it.
To prevent this from happening again, investigators need to understand why the crew became so confused.
Captain Chi: Why is it like this? Passengers: (Screaming) They dig deeper into the training records.
Lead Investigator: I'm not seeing any red flags.
The two pilots completed all licensing requirements, including classroom, simulator and training flights.
Everything seems in order.
But then, they notice something.
Lead Investigator: Hold on.
Something seems wrong here.
The simulator training.
Lead Investigator: A300 training, that's right.
Investigators contact China Airlines with questions about the pilots' simulator training.
Lead Investigator: You didn't have one at all? Oh, I see.
They learn that China Airlines did not have an A300 simulator for the pilots to train in.
Lead Investigator: Where did they do their training? The captain was sent to a simulator in Thailand to hone his skills in the A300.
Lead Investigator: You're not gonna believe this.
The simulator the captain trained on is in Bangkok.
It has a different configuration.
In Go Around mode, he can override the horizontal stabilizer.
If he pushed on the yoke, the SIM would go nose down.
Investigators are stunned to learn that the Thai simulator does the exact opposite of what the crash plane did.
When the pilot pushes forward on his control column, the nose goes down, even in Go Around mode.
Lead Investigator: That changes everything.
It's a major finding, one that could explain the captain's actions.
Captain Chi: Push down.
Push down more.
He may have thought that pushing the nose down would work because it worked in the simulator.
His years flying a 747 would have reinforced that belief.
Its flight systems work the same way.
Shawn Pruchnicki: In that aircraft, if you push the control yoke all the way forward it would force the autopilot to hand complete control back to the pilot.
But that's not what happens on the Airbus.
Captain Chi: Push down.
Push down more.
Shawn Pruchnicki: When humans are stressed, it's very common for us to regress back to previous experience.
Captain Chi: Go Around! First Officer Meng-Jung: Nagoya tower, Dynasty going around.
The first officer didn't have the experience to properly diagnose the problem.
Captain Chi: If this goes on, it will stall.
Shawn Pruchnicki: They essentially fell through the cracks in training.
They never got a chance to see this in a safe environment to understand why it's doing what it's doing and regain control of the aircraft.
Lead Investigator: Could you show me the section on disengaging Go Around mode? The Airbus manual also helps explain the pilots' confusion.
Lead Investigator: Disengagement of Go Around mode is possible only by engaging another mode.
Investigators discover that while Go Around mode is easy to turn on, it's much harder to turn off.
Lead Investigator: The ATS engages in the mode corresponding to the engaged longitudinal mode, whatever that means.
The longitudinal mode of Go Around remains active.
Well that's clear as mud.
Shawn Pruchnicki: You would think that it would be simple of just turning it off, deselect that function.
But that's not the way this automation is designed.
Captain Chi: We're still in Go Around mode.
A stressed young pilot could easily forget the multiple steps needed to de-activate Go Around mode.
Captain Chi: Push it down.
Ron Schleede: The co-pilot made an inadvertent movement of a switch that started this whole thing going.
I don't think either one of these pilots really understood what this was.
And they weren't the first.
In the previous 10 years, three other A300 crews experienced difficulty overriding the plane's automation.
Ron Schleede: There had been other incidents with these Airbus airplanes in which pilots had lost control of them.
Now they nearly crashed but they did not crash, and so the reasons for those incidents was the same as the reason for this accident.
After the last incident, Airbus issued a service bulletin, suggesting airlines modify all A300s.
Captain Chi: Push it down.
The modification would turn off automatic control of the stabilizer if the pilot pushed hard on the yoke in Go Around mode.
Captain Chi: Push down more.
Airbus issued the service bulletin less than a year before the China Airlines crash.
When investigators check the service records, they make an alarming discovery.
None of the company's six A300s had been modified.
Shigeru Saito: China Airlines decided to fix the computers later when the aircraft needed to be repaired for something else.
The recommendation wasn't mandatory so the airline just followed their own schedule.
Ron Schleede: The service bulletin is not a mandatory change for an airline.
Captain Chi: It's over! Captain Chi: Aaahhh! Ron Schleede: It's unfortunate that they didn't take these previous incidents and learn from them and they may have prevented this accident.
Although it once seemed the pilots were entirely at fault in the fatal crash, by the end of the two year investigation it's clear the plane's complex technology played a significant role.
After investigators release their findings, Airbus changes the flight systems to give pilots a manual override of the Go Around mode.
Training methods have also been updated.
Shigeru Saito: I want the world to be as safe a place as possible.
I don't want this to happen again.
So to avoid these accidents, finding solutions is important to help the next generation.
Captions edited by Ai-Media ai-media.
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