Original subtitles

NARRATOR: In the skies over Portugal…

SOKOLOV: What’s happening?

I have no control.

NARRATOR: The pilots of a passenger jet are in the fight of their lives.

KARASHOLAKOV: Mayday, mayday… Mayday.

DURÃO: I have never seen such an abrupt drop in altitude in an airplane.

LONG: This flight was the rollercoaster ride from hell.

NARRATOR: The crew is forced to make an unthinkable decision.

I think we have to ditch.

LONG: It's very unlikely that they would have had a good outcome.

NARRATOR: When investigators pore over the plane’s history.

This is confusing.

NARRATOR: They discover critical evidence that the plane was impossible to control.

INVESTIGATOR: That’s one big mistake.

AGHDASSI: What really surprised us was the fact that no one really noticed.

MAN (over radio): Mayday! Mayday!

(theme music playing throughout)

NARRATOR: Air Astana Flight 1388 prepares for takeoff from Alverca do Ribatejo,

an airbase 15 miles northeast of Lisbon, Portugal.

- Before takeoff checklist. - KARASHOLAKOV: Roger.

NARRATOR: 40-year-old Vyacheslav Aushev is the captain.

The veteran pilot has been flying with Air Astana for seven years.

- Radar? - On.

LONG: The captain of this crew had considerable time with Air Astana,

flying this aircraft, on which he had a great deal of experience.

He's got 6,000 flight hours.

Flaps?

NARRATOR: 32-year-old First Officer Bauyrzhan Karasholakov

is the pilot monitoring.

He’s been with Air Astana for five years.

Set for takeoff.

Before takeoff checklist complete.

Request takeoff clearance.

LONG: This flight crew was highly experienced in

the normal commercial operation role,

so they were selected because of those strengths.

ATC (over radio): Runway 0-4, cleared for takeoff.

Cleared for takeoff.

I'm looking forward to getting back home.

NARRATOR: To help with the journey, the airline has sent along an extra pilot,

26-year-old Sergey Sokolov.

SOKOLOV: That day I was a relief pilot because the flight

was long and I could switch my colleague if somebody tired.

NARRATOR: After undergoing maintenance work in Portugal,

today’s ten-hour flight has a stop in Minsk before

finally reaching Air Astana’s home base of Almaty, Kazakhstan.

There are no paying customers on board Flight 1388,

just three-maintenance staff employed by Air Astana.

SOKOLOV: The three passengers onboard were mainly responsible

for supplying the parts for the maintenance work in Portugal.

They were excited to come home.

NARRATOR: The recently serviced plane is a Brazilian-made Embraer E190.

LONG: It is a narrow-bodied, single-aisle,

twin-engined aircraft, which is used for medium range.

(dramatic music throughout)

V-1. Rotate.

NARRATOR: The flight takes off just after 1:30 pm.

Let’s go home.

NARRATOR: But seconds later…

(rattling)

What the?

NARRATOR: The plane hits some turbulence,

causing it to bank unusually hard to the left.

AUSHEV: After takeoff, the first indication was this

aircraft began to make a roll.

So that is the wrong movement of airplane.

That’s not normal.

SOKOLOV: What’s happening?

AUSHEV: There’s something wrong with the yoke.

I’ve never felt anything like this before.

KARASHOLAKOV: I felt the aircraft has too much, uh, oscillations.

And captain looked at me that we have some problem with flight controls.

No warnings or caution messages.

NARRATOR: The pilots can’t explain the plane’s erratic movements.

Flight 1388 is in serious trouble.

AUSHEV: I have no controls.

KARASHOLAKOV: Maybe it's the control column.

NARRATOR: The pilots search for a solution.

AUSHEV: Engage autopilot. KARASHOLAKOV: Autopilot on.

LONG: It was reasonable to expect that the autopilot to go, okay,

forget about the control column.

I will look after it because I've been programmed for the next phase of flight.

(beeping)

KARASHOLAKOV: Autopilot failed.

NARRATOR: The pilots are running out of options. They need help and fast.

We were in the clouds, an uncontrollable airplane in turbulent conditions.

AUSHEV: This is a mayday.

KARASHOLAKOV: Mayday, mayday, mayday.

KARASHOLAKOV (over radio): Climbing to 4,000 feet on heading 0-6-0.

Kilo-Zulu-Romeo 1388, roger mayday.

NARRATOR: Controller Viviana Durão receives

the distress call from the aircraft.

Go ahead with your request.

DURÃO: As soon as Air Astana departed, they declared mayday on the first contact.

We're all trained to deal with these kinds of emergencies.

But inevitably, your heartbeat goes a little bit faster and

your adrenalin peaks.

SOKOLOV: There’s nothing in the Quick Reference Handbook.

- We have to get back to the airport. - AUSHEV: Agreed.

Astaline 1388, requesting back to airport.

Kilo-Zulu-Romeo 1388, you can turn left or right as you wish heading 2-8-0.

AUSHEV: Roger.

NARRATOR: But heading back to the airport is an enormous challenge.

(grunting)

KARASHOLAKOV: Every time we bank, we lose altitude.

AUSHEV: We’ve got to get higher to turn back.

NARRATOR: To turn around safely, they need to climb or risk

hitting terrain when they bank.

If you roll excessively, the pitch doesn't actually

change much in terms of altitude and, in fact, will allow the aircraft to drop.

And that was alarming to say the least.

AUSHEV: Let’s try to control from your side.

KARASHOLAKOV: My controls.

I don’t think it’s any better, but I’ll try to climb.

SOKOLOV: What’s with the flight computers?

AUSHEV: Maybe there’s a software bug.

NARRATOR: The pilots speculate the problem is related

to the replacement of four flight computers,

something they learned about prior to takeoff.

LONG: They knew that there had been a new software load,

for the flight control system, so it's very, very easy and

sensible to make the conclusion that this is

possibly the result of a glitch in the uploaded software.

AUSHEV: Prepare to engage direct mode.

NARRATOR: By engaging direct mode, pilots can bypass the flight computers,

giving them full control.

- AUSHEV: My controls. - KARASHOLAKOV: Roger.

Your controls.

- SOKOLOV: Ready to engage direct mode? - AUSHEV: Engage direct mode for the roll.

NARRATOR: The aircraft’s performance improves.

KARASHOLAKOV: Let’s see if we can get back to Alverca.

NARRATOR: But the pilots’ relief does not last.

AUSHEV: It’s not enough.

I don’t have enough control to get us back to the airport.

LONG: The difficulty this crew had was they couldn't steer

the airplane in any way.

So to get back to the airport with the best will in the world

wasn't going to happen.

KARASHOLAKOV: What are we going to do?

NARRATOR: With nothing working, and the plane continuing to drop,

the crew is faced with a grim option.

SOKOLOV: I think we have to ditch.

NARRATOR: Ditching means attempting a very risky landing on water.

We were over the big populated city on uncontrollable airplane,

and we could hit the ground at any time.

We decided to ditch. This was one thing to stop this aircraft.

AUSHEV: Request vectors for the ocean. Sergey, take over comms.

And I will to need help with the throttle.

SOKOLOV: Astaline 1388.

SOKOLOV (over radio): Ditching. Request heading for ditching.

That is like a bad dream, yes, or bad movie.

SOKOLOV: The aircraft is, is uncontrollable.

1388, fly heading 2-6-0.

DURÃO: So I was very concerned, because I don't think any pilot

requests ditching lightly. So if they thought that that was their best option,

that meant they were in big trouble.

(dramatic music)

1388, you can reach the sea on a heading of 2-1-0, approximately 36 miles.

NARRATOR: For the last 18 minutes,

Flight 1388 has been flying erratically over Portugal,

unable to reach the Atlantic Ocean for a ditching.

KARASHOLAKOV: We keep losing altitude.

NARRATOR: Their biggest struggle is keeping the plane stable

enough to reach a safe altitude above the clouds.

LONG: If you can climb above the cloud then you do have that

visual horizon again, which is going to help you.

That buys you time to resolve the problem. And so altitude is good.

NARRATOR: Just when nothing seems to be working, the captain gets an idea.

AUSHEV: Let’s try the flaps. Give me flaps two.

SOKOLOV: Roger.

Flaps two.

We kept the flaps extended.

It helped us to stabilize the aircraft.

NARRATOR: 30 minutes after takeoff, Flight 1388 finally rises above the clouds.

KARASHOLAKOV: 17,000 feet and we have Visual Meteorological Conditions.

DURÃO: That was actually a good sign because if they could

control the aircraft enough to climb over clouds,

they weren't going to crash any time soon. This was very good news.

(dramatic music)

NARRATOR: But then, without warning,

the plane plummets towards the earth at 20,000 feet per minute.

KARASHOLAKOV: And we suddenly plunged to the left and dived with quick descent.

Physically, it was, uh, horrible.

NARRATOR: For the three passengers on board, it’s a rough and terrifying ride.

DURÃO: Oh no.

I had never seen such an abrupt drop in altitude in an airplane,

and this was very scary because we had no idea when they were going to stop.

- AUSHEV: Pull up! - KARASHOLAKOV: Pulling up!

NARRATOR: 40 seconds into the dive, the plane descends below cloud cover.

(tense music throughout)

AUSHEV: Keep it up. We've got this. Sergey, we need power.

LONG: During that rapid descent there would have been slightly

less than one G, one times the force of gravity.

But, at the point at which you pull the airplane out of

the dive, that G level picks up,

and in this case almost at fighter pilot levels.

NARRATOR: The extreme maneuver stresses the airframe to its limit.

AUSHEV: We heard like some cracking… (makes cracking sounds).

Of the airplane, of the of the G load.

(grunts)

SOKOLOV: I saw the hill with the trees in front of us. It was close.

NARRATOR: The plane holds together.

KARASHOLAKOV: 8,000 feet and climbing.

NARRATOR: The pilots pull out of the dive just in time.

AUSHEV: Well done.

Yeah, wow, we’re out of this nightmare.

(rattling)

Okay, let’s try to get back on course towards the ocean.

SOKOLOV: Astaline 1388.

SOKOLOV (over radio): Can you confirm our position in relation to the sea please?

If you fly southbound, you need to go 36 miles.

NARRATOR: But the battered aircraft still isn’t responding

predictably to the crew’s inputs.

AUSHEV: It’s no good. I can’t get to 2-2-0.

See if I can stay on this heading.

SOKOLOV: 1388, we are flying through a storm.

Can we get to the sea on our current heading?

DURÃO: The weather was very bad, very windy,

raining and the cloud ceiling was very low.

If you can fly westbound, you will reach the sea.

SOKOLOV (over radio): We’ll try.

NARRATOR: 35 minutes into the flight,

Air Traffic Control calls the Portuguese Air Force for help.

DURÃO: The Air Astana was still in an area with very bad weather.

They were having trouble navigating.

And so we hoped that with the guidance of the F-16's,

they could reach an area with, with better weather conditions.

NARRATOR: Lieutenant Colonel Nuno Monteiro is one of two F-16 pilots

sent to guide the aircraft to better weather, and a place to ditch safely.

MONTEIRO: It was the worst day in terms of weather.

Uh, I was in the squadron and I knew that if the bell would ring that day,

we had to act fast.

NARRATOR: But can the F-16's reach Flight 1388 in time to help?

NARRATOR: Almost an hour into their trip,

Flight 1388 awaits help from two Portuguese fighter jets.

KARASHOLAKOV: Still climbing. Anybody need water?

NARRATOR: But the pilots are exhausted.

KARASHOLAKOV: It was very hard for us, physically and emotionally.

SOKOLOV: Can one of you bring us some water up here, please?

(dramamtic music throughout)

- AUSHEV: Your controls. - KARASHOLAKOV: My controls.

(sighs)

(sigh)

What do you know about the maintenance that was done on this aircraft?

AZAMAD: They did a lot of work, replaced some parts too.

AUSHEV: Anything flight control related?

- AZAMAD: We ordered new aileron cables. - SOKOLOV: New aileron cables?

When we learned that aileron cables were changed,

we realized the possible cause of the problem.

NARRATOR: Ailerons are flight control surfaces on the rear edge of each wing.

They hinge up and down to help control an aircraft’s roll.

AUSHEV: Let’s check them.

(tense music throughout)

AZAMAD: I’ve got visuals on the right wing.

AUSHEV: Inputting ailerons right.

NARRATOR: As the captain turns the control column to the right,

the right-wing aileron should lift.

AZAMAD: Aileron going down, turning left.

KARASHOLAKOV: That’s wrong.

AUSHEV: Let’s try the reverse.

AUSHEV (over speaker): Inputting aileron left.

KARASHOLAKOV: We put inputs and we realized that this ailerons

is responding opposite.

AUSHEV: The ailerons are reversed.

SOKOLOV: With opposite inputs, we might be able to control the aircraft.

Now we know what's happening. Let's start to work with this.

Okay, let's fly this aircraft oppositely.

If you want to turn left, turn to the right.

KARASHOLAKOV: It’s a bit better but still hard to fly.

AUSHEV: This is going to take some getting used to.

NARRATOR: Against his instincts and muscle memory,

the captain tries to keep the plane’s wings level and climb to better weather.

LONG: You have to learn a completely different process

against the ingrained teaching you've already had, and that's very difficult.

NARRATOR: 61 minutes into the flight, help finally arrives.

DURÃO: Astaline 1388. You have two F-16's reaching your position.

SOKOLOV: Copy that.

MONTEIRO (over radio): Kilo-Zulu-Romeo this is Portuguese Air Defense, Bullet-21.

How can we assist?

The altitude, the heading, the speed were far from being stable.

And I had a lot of doubts at this moment what can we do

to help Air Astana flight?

SOKOLOV: We have a flight control problem and no visibility.

Maintaining flight level 1-4-0 west-bound and will make ditching on sea.

MONTEIRO: I thought, come again?

I have never heard this call in my life as a,

as a pilot and I've been an aviator, um, for the past 25 years.

I feared for them.

NARRATOR: But given the weather, would they even survive a ditching in the ocean?

LONG: If the sea is very rough and you're trying to land across

three meters or so of swell it's very unlikely that

they would have had a good outcome.

NARRATOR: Lieutenant Colonel Monteiro proposes a different plan.

MONTEIRO: If you have 70 miles of fuel, you could try Beja.

NARRATOR: The closest airport with good weather is Beja,

a military airport 70 miles to the south.

KARASHOLAKOV: If we follow the F-16s, do you think we could land this thing?

SOKOLOV: We have enough fuel.

AUSHEV: Let’s try.

SOKOLOV: Now we could stably climb above the clouds.

The F-16 means we are not alone in the sky and the F-16 can lead us

to an airport with a better weather.

The aircraft is a little bit more controllable.

MONTEIRO (over radio): Confirmed. We’ll help you land.

SOKOLOV: Can you confirm heading for Beja Airport?

Beja is a suitable aerodrome, heading 1-9-5.

- SOKOLOV: Right heading 1-9-5. - AUSHEV: Okay.

Let’s see if we can land this plane.

NARRATOR: Using the F-16 on their left as a visual reference,

Flight 1388 heads to Beja airfield.

MONTEIRO (over radio): I’ll guide you in. Do you have a visual on me?

SOKOLOV: Affirmative. Thank you for helping, sir.

We disregarded the ditching because now we at least know how to fly this aircraft.

Now we need to land it.

Now we have chance to survive.

When you flying oppositely, it's really hard to keep it

straight and level 100% of the time.

We understood that landing will not be easy.

We are now six miles from runway.

NARRATOR: After 15 minutes of flying towards Beja airfield,

the crew begins to configure the plane for a challenging landing.

KARASHOLAKOV: Flaps four.

(grunts)

- AUSHEV: Whoa! - KARASHOLAKOV: Watch out.

NARRATOR: But the stability of the aircraft gets worse.

SOKOLOV: We flew flaps two, and now flaps five,

landing gear down, so these conditions is new for, for this airplane.

So it means you have to learn to fly it again.

NARRATOR: With the ailerons reversed,

Flight 1388 is almost impossible to control.

Both F-16s position themselves behind the plane,

giving the crew plenty of space, without distraction.

KARASHOLAKOV: 1,000 feet. You got this.

AUSHEV: The guys support me and say yes, yes, you're doing great.

Everything will be okay. We will survive.

NARRATOR: Less than 1,000 feet from the runway,

the pilots struggle to keep the plane level.

SOKOLOV: With the low speed on the approach,

you have to have minor inputs on the yoke,

and it's really difficult.

NARRATOR: The aircraft begins to veer away from the runway.

- AUSHEV: Go around! - SOKOLOV: Going around.

NARRATOR: It’s too dangerous to put the plane down. They abort the landing.

AUSHEV: I don’t think I can do this. We have to try something else.

NARRATOR: The pilots are determined to try again, but can they make it?

SOKOLOV: I looked at the guys and I saw that we all wanted to

solve this problem and bring this aircraft to the ground.

COMPUTER: Warning. Warning. Warning. Warning. Lock.

NARRATOR: After nearly two hours in the air and two unsuccessful landing attempts,

Flight 1388 flies towards the runway again.

SOKOLOV: Turning left, heading 1-8-9. I'm going to take us back in.

MONTEIRO (over radio): Roger.

NARRATOR: With the Captain and the First Officer exhausted,

the Relief Pilot takes the controls for the third landing attempt.

AUSHEV: That's like in football when you need a win goal, you change the player.

KARASHOLAKOV: It’s going to try and get away from you.

Be ready for anything.

SOKOLOV: I was less tired but I realized that

it's really difficult to control the airplane.

AUSHEV: There’s 1,000. Watch for the right roll as we get down.

SOKOLOV: 1,000.

KARASHOLAKOV: We’re drifting too far to the left.

SOKOLOV: I’m trying to get back to center.

NARRATOR: A mile from the runway, the weather impedes the landing attempt.

The wind conditions changed. The plane started to deviate again to the left.

NARRATOR: The captain quickly improvises an alternate plan.

AUSHEV: We can make it to the other runway there, 1-9 Left.

SOKOLOV: I see it. I’ll try.

- AUSHEV: Can we land on the left runway? - ATC (over radio): Confirmed.

- Cleared to land on left runway. - AUSHEV: Roger.

(dramatic music throughout)

SOKOLOV: Here we go.

(dramatic music crescendoing)

(calming music throughout)

NARRATOR: After a grueling two hours in the air, Flight 1388 lands safely in Beja.

(laughs)

SOKOLOV: We did it!

(laughter)

(laughter)

NARRATOR: Through teamwork and determination,

the crew has made a stunning landing.

SOKOLOV: I was happy. The flight is finished, aircraft brought in to stop and

we finally can say we've done it.

MONTEIRO (over radio): Godspeed men. I’m so glad you’re on the ground.

It was one of the happiest moments in my life as a, as a military pilot.

I felt relieved and I felt extremely thankful,

uh, to see that aircraft on the ground.

NARRATOR: The only injury is a sprained ankle to one of the maintenance staff.

KARASHOLAKOV: I felt relief. I was very happy that we, we made it and we landed

the aircraft, uh, in one piece.

NARRATOR: But now it’s up to Portuguese Air and Rail Accident

investigators to find out why it happened at all.

Within two hours of landing, investigators from

the Portuguese Safety Investigation Authority arrive at Beja Airbase.

José Figueiredo is the lead investigator overseeing the investigation.

FIGUEIREDO: Good to see it's in one piece.

We knew that something was wrong, really wrong with the, the aircraft.

NARRATOR: Investigators examine the aircraft for signs of damage.

FIGUEIREDO: Nose looks fine.

Check this out. Deformations.

AGHDASSI: There wasn't any visible damage as we approached the aircraft.

However, we found wrinkles on the surface of the fuselage and

on the leading edge of the wing.

NARRATOR: The damage indicates that Flight 1388 suffered extreme forces in flight.

I can’t believe they landed this plane.

NARRATOR: The incident is declared an accident,

because of the severity of the damage.

The aircraft is a write-off.

The definition of an accident typically involves

the destruction of the aircraft and fatalities,

but we decided to classify this event an accident rather than an incident,

because we felt it was important to draw attention to what happened here.

FIGUEIREDO: Let’s see what the crew can tell us.

We called the control tower at Beja and request the pilots to

stay on the aircraft until we arrived there.

AGHDASSI: It was key for us to speak to the pilots so that we

could get a first-hand account of what had occurred,

and to try and get as much valuable information from them as possible.

When did you realize there was a problem?

Immediately after takeoff, the plane started rolling back and forth.

(rattling)

SOKOLOV: What’s happening?

AUSHEV: There’s something wrong with the yoke.

I’ve never felt anything like this before.

There’s a total disconnect between the control yoke and the aircraft.

Were there any alerts or indications of what went wrong?

No, but one of the maintenance team onboard

remembers ordering new aileron cables for the aircraft.

So we did a visual inspection and it seems the ailerons were moving in the reverse.

FIGUEIREDO: We couldn't believe it when the crew told us.

We wanted to perform an operational test to confirm,

for ourselves, what was the real issue.

Okay. Show us the left aileron.

Copy.

NARRATOR: Investigators test the ailerons to verify that

they were moving in opposite directions.

Yoke to the left.

NARRATOR: Two control surfaces work in tandem to turn the plane.

Both the aileron and the spoiler must move upwards on the wing

to turn the plane to the left.

(dramatic music throughout)

The spoiler's fine but the left aileron moved down, instead of up.

It’s reversed.

AGHDASSI: It's as if the steering wheel of your car was

giving inverted commands, or the handlebar of your bicycle was inverted, as well.

The plane would have been next to impossible to control.

AGHDASSI: The next big question the investigation was facing was

how did this happen?

FIGUEIREDO: Maintenance began on October 2nd.

NARRATOR: Investigators review Flight 1388's maintenance records,

for an explanation why the ailerons were inverted.

And it continued up until the morning of the accident.

NARRATOR: The aircraft was serviced in Portugal for a month

by a third-party company owned by Embraer.

LONG: When airlines don’t have the maintenance facilities

capable of doing the deep servicing, they contract external suppliers,

and that was the case here.

AGHDASSI: It was necessary to find out what had happened

during the month or so that the aircraft was in maintenance.

NARRATOR: Investigators meet with the maintenance supervisor

to find out more about the work performed on the aircraft.

FIGUEIREDO: Why did the plane require aileron maintenance service?

SUPERVISOR: The aileron cables were old.

NARRATOR: When commanded, four aileron cables move the ailerons up and down.

Each cable moves through a pulley system.

Cable friction on the pulleys can cause premature wear.

We replaced the pulley system with a frictionless one,

to prevent future wear and tear.

Operators had complained to Embraer about

the premature wear on the stainless steel cables,

so Embraer came up with a design fix to this issue,

and the aircraft was being refitted with the new contactless system.

It says here the aileron maintenance began on October 9th.

Correct, uh. The structures team started by removing the old pulleys and cables.

NARRATOR: The new installation uses mostly square metal frames

instead of pulleys to guide the cables through the wing.

This minimizes any wear caused by friction.

And what did the structures team do next?

They reinstalled the old cables as a temporary measure,

until the flight control team installed the new cables.

AGHDASSI: The structures team reinstalled the old cables once

they had finished replacing the hardware,

because that is what the procedures required them to do.

They were following the instructions.

Is it possible that they inverted the old cables when they reinstalled them?

It’s possible.

I'm told they had a hard time following the instructions.

FIGUEIREDO: Where’d they struggle with the instructions?

SUPERVISOR: Right here.

NARRATOR: They identify a key section,

where the structures team had difficulty understanding the instructions.

This looks like the reverse zone.

NARRATOR: The reverse zone is a two-meter-long section inside

the wing where the cable routing changes from horizontal to vertical.

This is confusing.

Did the technician ask for help?

I’m told he asked another engineer on the team.

FIGUEIREDO: The structural engineer consulted a colleague,

who had also limited experience and the manual instructions

were quite difficult to follow.

Did you test your re-installation?

They weren’t required to.

This kind of work requires extensive experience.

So without surprise they did it incorrectly.

NARRATOR: Not only did the structures team incorrectly

reinstall the old cables, they never tested the ailerons

to confirm that they installed them correctly.

FIGUEIREDO: The structures team were informed that the fight control team

will come later to replace those cables.

Did the flight control team catch the error?

Not likely. I’m told they installed the new cables following the same routing.

FIGUEIREDO: The flight control team replaced the cables one by one,

installing the new cables as a direct replacement and

without verifying the previous routing.

NARRATOR: So why didn’t the flight control team discover

the mistake after they finished the installation and then tested the ailerons?

Investigators check the Fault History Database for answers.

AGHDASSI: The Fault History Database records data about

the maintenance work that was done on the aircraft.

So it will tell us, for example, when the aircraft was powered up,

when it was powered down, what systems were operating, and at what time.

Installation of the new cables was completed on October the 17th.

FIGUEIREDO: Well according to this, they couldn’t test the ailerons on the 17th.

The plane was still under maintenance.

The investigation knew that the ailerons had not been checked on that day,

because you need to power up the aircraft and from

the data that we could see in the Fault History Database, this never happened.

Well when did they complete the maintenance?

FIGUEIREDO: On October 26th they finished the additional

maintenance and powered up the plane.

Did they test the ailerons then?

FIGUEIREDO: It doesn’t look like they could.

Oh, they got a fault warning in the cockpit. Flight control no dispatch.

AGHDASSI: Flight control no dispatch is a catch-all message, which alerts the

flight crew that something needs attention before going flying.

It could be a sensor. It could be a connection that is loose.

They didn’t know what caused the fault.

Regardless, they can’t fly with the error message.

NARRATOR: While the error message had nothing to do with

the inverted aileron cables, it diverted technicians’ attention

away from the aileron repair.

AGHDASSI: And so when they experienced the flight control no dispatch,

this put a lot of pressure on all of the maintenance technicians.

FIGUEIREDO: What did you do when your crew got

the flight control on no dispatch message?

NARRATOR: Investigators delve into how the maintenance team of

Flight 1388 dealt with a no fly error message after completing

maintenance work on the plane.

I dispatched a team to investigate.

Were they able determine the issue and clear the problem?

No.

AGHDASSI: The maintenance team started by referring to the manuals.

They also asked support from the manufacturer.

However, all of these efforts had a limited result.

How did they resolve the error message?

They replaced the flight control computers.

NARRATOR: With no success resolving the error message,

the maintenance team considers the possibility

that the issue involves the flight control computers.

AGHDASSI: These were new computers so these,

being new computers, they have clean memories.

SUPERVISOR: When they powered up the plane, the error message was gone.

AGHDASSI: When those four flight control modules were replaced,

the message disappeared and the plane was cleared to fly.

Did you test the ailerons after that?

Sure did. We checked all the flight controls.

And what about a visual check?

Absolutely. They were moving up and down, no problem.

Did they check to see that they were moving in the right direction?

Ah. Uh, I’m sorry. I’m not sure they did or not.

AGHDASSI: The operational checks were performed.

However, no one really noticed that despite

the movement of the ailerons that, in fact,

they were moving in the opposite direction to what is being commanded.

FIGUEIREDO: Thanks for your time.

Well that’s one big mistake that nobody caught.

NARRATOR: Investigators finally understand what happened to Air Astana Flight 1388.

The groundwork for the terrifying flight was laid

a month earlier when a maintenance team inverted

the aileron cables because the instructions were confusing.

When they prepare to test the aileron cables,

they get distracted by a mysterious error message.

Maintenance technicians clear the error message by replacing flight computers.

But when they check that the ailerons are working,

they never look to see what direction they're moving.

(rattling)

SOKOLOV: What’s happening?

AUSHEV: There’s something wrong with the yoke.

I’ve never felt anything like this before.

NARRATOR: This chain of events sets Flight 1388 on

a harrowing 116-minute flight.

AUSHEV: There’s 1,000. Watch for the right roll as we get down.

SOKOLOV: 1,000.

NARRATOR: Remarkably, they are able to overcome

their difficulties through focus and good teamwork.

MONTEIRO (over radio): I’ll guide you in. Do you have a visual on me?

NARRATOR: The aid of an experienced fighter pilot

finally helps them to land the plane.

DURÃO: The situation looked dire for, for a long time.

And knowing that they had landed safely was just a tremendous relief.

LONG: The really impressive thing is that this crew,

who were not experienced flight test pilots who'd come

across completely non-standard situations before,

just how quickly they settled down to work it through logically.

They did really well.

NARRATOR: As a result of this accident and investigation,

several safety changes are made.

AGHDASSI: There were a lot of changes at Embraer,

in terms of revising their manuals and making the instructions much

clearer when it comes to replacing the aileron control cables.

NARRATOR: Air Astana installed more robust procedures for

checking aircraft after completing maintenance.

AGHDASSI: New procedures were made for checking

the flight controls, including making sure the correct movement of the ailerons.

Maintenance errors have occurred in the past,

and I think what this event demonstrates is that it underscores

the importance that all of the stakeholders, including maintenance,

play in achieving flight safety.