Original subtitles

A mechanics error in judgment...

Well, it wasn't that busy so I offered to help the guys.

Well, it wasn't that busy so I offered to help the guys.

...leads to a mid-flight disaster.

High speed.

To find out later that something they did

To find out later that something they did

or an airplane they had worked on went down,

that's got to be a special level of hell.

that's got to be a special level of hell.

Reach over here.

Botched maintenance leads to a life

and death struggle in the sky.

and death struggle in the sky.

Emery 17, extreme balance problem.

Ah!

Ah!

Three pilots lost their lives because of a bolt,

a nut, and a Cotter key.

a nut, and a Cotter key.

Sometimes the failure of a tiny piece of the plane

Sometimes the failure of a tiny piece of the plane

can lead to tragedy.

A trio of crashes reveals the critical importance

A trio of crashes reveals the critical importance

of following the proper procedures for maintenance.

In each of these cases, the plane

In each of these cases, the plane

was lost because of a bolt.

Ladies and gentlemen,

we are starting our approach.

We lost both engines.

We lost both engines.

Put the mask over your nose.

- Emergency. - Mayday.

Mayday.

Brace for impact!

It's gonna crash!

Autopilot off.

Continental Express flight 2574

nears the end of its hour-long flight from Laredo

nears the end of its hour-long flight from Laredo

to Houston, Texas.

There are 11 passengers on board.

There are 11 passengers on board.

2574.

They're going to bring everybody in on 26 or 27.

They're going to bring everybody in on 26 or 27.

Okie, dokie.

The pilots prepare the Embraer 120 Brasilia

for their second landing of the day.

for their second landing of the day.

Captain Brad Patridge is just 29 years old.

The first officer, Clint Rodosovich is 43.

The first officer, Clint Rodosovich is 43.

The two have close to 16,000 flying hours between them.

The two have close to 16,000 flying hours between them.

Pushing this descent.

Making like the space shuttle.

High speed.

High speed.

Within seconds, the aircraft's steady descent...

Within seconds, the aircraft's steady descent...

Stall.

Stall.

...becomes an uncontrolled free-fall.

...becomes an uncontrolled free-fall.

Flight 2574 nosedives almost 12,000 feet

Flight 2574 nosedives almost 12,000 feet

and hits the ground at a speed exceeding 300 miles an hour.

What we see on the ground is not

recognizable in any shape, form, or fashion

as having been an airplane.

as having been an airplane.

The broken-up aircraft has plunged

into the middle of a field about an hour west of Houston, Texas.

into the middle of a field about an hour west of Houston, Texas.

All 14 people on board are dead.

A team of investigators from the National Transportation Safety

A team of investigators from the National Transportation Safety

Board arrives at the crash site.

I was a little bit scared when I first saw the wreckage.

I was a little bit scared when I first saw the wreckage.

The airplane was destroyed and there wasn't a lot to go on.

The airplane was destroyed and there wasn't a lot to go on.

But the black boxes are found and rushed to NTSB

headquarters in Washington DC.

The spread of the wreckage gives investigators

The spread of the wreckage gives investigators

much needed information.

I saw the cockpit was there.

The fuselage was there.

The left wing had folded under the right wing.

The left wing had folded under the right wing.

And a portion of the vertical stabilizer was there.

And a portion of the vertical stabilizer was there.

But the horizontal stabilizer was missing.

But the horizontal stabilizer was missing.

The Embraer 120 is what's

called a T-tail airplane because the horizontal stabilizer sits

called a T-tail airplane because the horizontal stabilizer sits

on top of the tail.

It's found more than 200 yards from the debris field.

Can someone help me get a bearing on this?

That made me believe that there is

That made me believe that there is

definitely an in-flight breakup of an airplane.

I'm guessing that tail came off at about 9,000 feet.

I'm guessing that tail came off at about 9,000 feet.

I'm guessing that tail came off at about 9,000 feet.

We started to look at the fracture surfaces

We started to look at the fracture surfaces

of the vertical stabilizer.

The edges are jagged, indicating the tail

was ripped off suddenly.

And there's another clue.

I noticed that the leading

I noticed that the leading

edge on the left side horizontal stabilizer was missing.

The leading edge is a rounded piece that

allows air to pass over the stabilizer

allows air to pass over the stabilizer

and keep the plane steady.

A key question there is, what was the first part

A key question there is, what was the first part

that came off of the airplane?

Because a lot of times, the initiating event

is going to be found in those early parts

is going to be found in those early parts

that break from the airplane in an in-flight break-up.

The leading edge is not near the crash site.

Finding it will be key to discovering

what happened to flight 2574.

what happened to flight 2574.

As searchers combed the area, the investigators

As searchers combed the area, the investigators

receive a copy of the cockpit voice recording

from the lab in Washington DC.

from the lab in Washington DC.

Radio check.

Radio check.

I can hear you loud and clear.

I can hear you loud and clear.

As you also.

OK, I'll get you some.

OK, I'll get you some.

All right.

Most of the recording sounds routine.

Jetlink 2574, say your heading.

Jetlink 2574, say your heading.

050.

There is no hint of trouble until...

There is no hint of trouble until...

Pushing this descent.

Making like the space shuttle.

The engines suddenly start to roar.

The engines suddenly start to roar.

Flight warning alarms scream.

Stall.

Stall.

Stall.

Stall.

And all conversation ends.

The recording tells investigators

The recording tells investigators

the pilots had no advance warning

of their plane's nosedive.

of their plane's nosedive.

The event happened extremely fast.

I don't think there was anything that the crew could have done.

I don't think there was anything that the crew could have done.

Analysis of the flight data recorder

confirms that conclusion.

We didn't see anything

unusual about the accident flight until the very instant

unusual about the accident flight until the very instant

that we had the pitch down.

that we had the pitch down.

The cause of the crash remains a mystery.

Investigators will need to locate the missing leading edge

to find out what went wrong.

The missing piece is 10 feet long.

Investigators calculate that it must

Investigators calculate that it must

be hidden somewhere in an area covering

four and a half square miles.

four and a half square miles.

We were doing marches through the area.

We were doing marches through the area.

And after several days went by, it was difficult.

We had flights by the local volunteer groups

were flying over the site.

were flying over the site.

The piece is nowhere to be found.

I think it's somewhere in here.

I think it's somewhere in here.

Over the next couple of days, we went to that area,

and we laid out a grid to search for it.

and we laid out a grid to search for it.

We searched for it on...

in the four-wheelers and in the helicopter.

in the four-wheelers and in the helicopter.

On the third day, the investigation

gets a much needed break.

gets a much needed break.

We were flying over the Texas countryside,

big cattle country.

Suddenly the pilot sitting next to me said, I think I see it.

Suddenly the pilot sitting next to me said, I think I see it.

We were really excited.

You want to do your best to understand

what happened in an accident.

And if you didn't have the key part,

And if you didn't have the key part,

there would always be questions.

The state of the leading edge

raises more questions.

The lower surface holes under the leading edge

The lower surface holes under the leading edge

were elongated.

They were cracked as if you have pulled

They were cracked as if you have pulled

it through the fasteners.

But the holes that hold

But the holes that hold

the piece to the top of the stabilizer

look quite different.

The evidence indicated that the leading edge

The evidence indicated that the leading edge

upper surface holes were absolutely clean,

upper surface holes were absolutely clean,

no elongation, no damage.

Screws on top.

It looked like there was no screws attached

It looked like there was no screws attached

onto the top surface of the horizontal

stabilizer leading edge.

stabilizer leading edge.

Investigators now need to answer two questions.

Why were the screws missing?

Why were the screws missing?

And...

Losing this actually caused the plane to crash?

Losing this actually caused the plane to crash?

With all of the pieces of Continental Airlines flight

2574 now recovered, the investigation moves to the NTSB

2574 now recovered, the investigation moves to the NTSB

headquarters in Washington DC.

Investigators first need to know how the left leading edge...

found nearly a mile from the rest of the tail section...

found nearly a mile from the rest of the tail section...

is connected to the crash.

Well, we were just trying to make sure that we understood

Well, we were just trying to make sure that we understood

what the motion of the airplane was after the leading

edge radius broke off.

edge radius broke off.

The horizontal stabilizer

is like an upside-down wing.

It pushes the tail down while the wings lift it,

It pushes the tail down while the wings lift it,

reducing the downforce when the stabilizer lifts the tail

and makes a plane pitch downwards.

and makes a plane pitch downwards.

Engineering simulations suggest that losing just one

Engineering simulations suggest that losing just one

leading edge would change the aerodynamics

enough to send the plane into a catastrophic nosedive.

enough to send the plane into a catastrophic nosedive.

If there is any component of the wing

If there is any component of the wing

that you don't want to lose, it's the leading edge.

To learn why the leading edge might have come

To learn why the leading edge might have come

off during the flight, investigators

examined the airline's maintenance records

and make an intriguing find.

and make an intriguing find.

The night before the fatal accident,

maintenance crews repaired the plane's de-ice boots.

maintenance crews repaired the plane's de-ice boots.

The de-ice boot is a rubber bladder that, when inflated,

The de-ice boot is a rubber bladder that, when inflated,

breaks up ice on the wings and tail.

We wanted to interview every mechanic,

We wanted to interview every mechanic,

supervisor, and inspection person

who took part in that activity.

who took part in that activity.

Investigators speak with two maintenance crews,

the evening shift, which started the work,

the evening shift, which started the work,

and the midnight shift, which finished it.

Replacing the boot involves removing the leading edge,

Replacing the boot involves removing the leading edge,

stripping off the old boot, and replacing it with a new one.

stripping off the old boot, and replacing it with a new one.

The entire piece is then screwed back on

to the horizontal stabilizer.

to the horizontal stabilizer.

The evening shift inspector, Troy Anderson,

should be watching over his team when

they remove the screws holding the leading edges in place.

they remove the screws holding the leading edges in place.

But that night, he wasn't just supervising his team.

But that night, he wasn't just supervising his team.

I had some time to lend a hand.

We went up to the stabilizer to start the job.

We went up to the stabilizer to start the job.

When mechanics started working on the bottom,

the inspector volunteered to climb up on top of the thing

the inspector volunteered to climb up on top of the thing

and get the top ones.

But when the evening shift clocks off

But when the evening shift clocks off

and the midnight shift begins, evening shift mechanics

hadn't finished removing badly stripped screws

hadn't finished removing badly stripped screws

on the right side leading edge.

And it was looking like they weren't

going to get both sides done.

Well behind schedule, midnight shift supervisor Adam

Well behind schedule, midnight shift supervisor Adam

Dillon makes a critical decision.

Dillon makes a critical decision.

Guys, forget the left side for tonight.

Let's get this plane out of here.

Let's get this plane out of here.

So your mechanics didn't do any work

at all on the left side?

No.

No.

We didn't touch it.

After changing the de-ice boot on the right side

only, the aircraft is rolled out to the gate for

only, the aircraft is rolled out to the gate for

the first flight of the day.

Three hours later, the left leading edge rips off.

Three hours later, the left leading edge rips off.

Investigators suspect that the screws were removed

from the top of the left side's leading edge

and never replaced.

and never replaced.

They speak with Troy Anderson again.

So which side did you work on, Troy?

So which side did you work on, Troy?

Just the right?

Both.

Look, when I left, the plan was to do both sides.

The inspector went up on the manlift

and started helping the mechanics.

and started helping the mechanics.

That's not his job.

It wasn't his role.

It wasn't a good idea.

It wasn't a good idea.

To make matters worse, no one recorded that the screws

were removed by the inspector.

were removed by the inspector.

The midnight shift had no idea that the leading edge

needed to be secured in place.

needed to be secured in place.

On a shift turnover, that's one of the critical things

that you have.

You have a written record that anyone can go back to.

It wasn't done.

It wasn't done.

Investigators now know that a failure

in routine maintenance caused the crash of Flight 2574.

in routine maintenance caused the crash of Flight 2574.

The significance of First Officer Rodosovich's last words

The significance of First Officer Rodosovich's last words

is now tragically clear.

Pushing this dissent.

Pushing this dissent.

Making like the space shuttle.

The pilots increased their speed,

The pilots increased their speed,

putting extra stress on the horizontal stabilizer.

The airplane broke apart at the highest speed

The airplane broke apart at the highest speed

that it reached since the maintenance

was done the night before.

was done the night before.

The aerodynamic forces were very high.

And so, eventually, they were enough to bend the leading edge

radius downward because it wasn't

radius downward because it wasn't

attached anymore on the top of the horizontal tail.

And they bent it downward to the point

And they bent it downward to the point

where, finally, the oncoming air was powerful enough

to break it off.

The aircraft hurtled to Earth at an astounding 320

The aircraft hurtled to Earth at an astounding 320

miles per hour.

On the cockpit voice recording,

On the cockpit voice recording,

the pilots don't say anything after it happens.

They were probably incapacitated.

It's that violent.

In the final report, the NTSB

In the final report, the NTSB

faults Continental Express for not ensuring

that the mechanics and inspectors

completed paperwork correctly.

completed paperwork correctly.

This was a preventable accident.

If they had strictly followed those procedures,

If they had strictly followed those procedures,

this accident should not have happened.

As a result of the crash,

As a result of the crash,

airlines now use computerized systems to meticulously track

mechanics' work.

mechanics' work.

It was an important step in the evolution of safety

It was an important step in the evolution of safety

and the safety of parts.

So it was a small plane with a big impact.

So it was a small plane with a big impact.

When a cargo jet loses control after takeoff...

Emery 17, emergency.

Emery 17, emergency.

Emery 17, say again?

Investigators find the smallest of culprits.

Mather Airport, Sacramento, California.

Mather Airport, Sacramento, California.

You flew jump seat from Dayton, right?

Yes, sir.

Captain Kevin Stables is preparing to pilot Emery

Captain Kevin Stables is preparing to pilot Emery

Worldwide flight 17.

His first officer is George Land.

His first officer is George Land.

Inspections complete.

Cargo doors closed.

Joining the pilots is flight engineer Russell Hicks.

Joining the pilots is flight engineer Russell Hicks.

They're flying freight from Sacramento

to Dayton, Ohio on a 30-year-old DC-8 cargo plane.

to Dayton, Ohio on a 30-year-old DC-8 cargo plane.

The DC-8 is a fantastic plane.

The DC-8 is a fantastic plane.

The thing was built like a tank.

It was kind of a pilot's plane.

It took a lot of work and it took a lot of physical effort.

It took a lot of work and it took a lot of physical effort.

80 knots.

Elevator checks.

V1.

V1.

Rotate.

As the nosewheel leaves the ground,

As the nosewheel leaves the ground,

the DC-8 pitches upward more steeply than expected.

Watch the tail.

Watch the tail.

The sudden takeoff is quickly followed

by an uncommanded left bank.

Center of gravity is way out of limits.

They need to return to the airport

They need to return to the airport

as quickly as possible.

Emery 17, emergency.

Emery 17, say again?

Emery 17, say again?

Emery 17, we have an emergency.

You steer.

I'm pushing.

I'm pushing.

The DC-8 starts climbing again.

Oh!

Emery 17, extreme balance problem.

Emery 17, extreme balance problem.

Pull up.

Push.

Push.

Pull up.

Push forward.

Pull up.

In a desperate effort to level the plane,

they exert maximum force on the control column.

they exert maximum force on the control column.

Power.

More?

More?

Yeah.

Left turn.

OK.

OK.

The airplane started to go

into these big perturbations, dive,

and then climb, dive, and then climb.

and then climb, dive, and then climb.

You steer.

I'm pushing.

So now you have three pilots trying to work in harmony.

So now you have three pilots trying to work in harmony.

That's good from a cockpit resource management standpoint.

Three, three.

Pull up.

Three, three.

Pull up.

Pull up.

We're sinking.

We're going down, guys.

All right.

All right.

Pull up.

Pull up.

Three.

Pull up.

The crippled plane is now within sight of the runway.

The crippled plane is now within sight of the runway.

But it's already too late.

Emery flight 17 has crashed

into a scrap yard, one mile east of Sacramento's Mather airport.

into a scrap yard, one mile east of Sacramento's Mather airport.

All three crew members are dead.

All three crew members are dead.

Investigators from the NTSB sift through a debris

Investigators from the NTSB sift through a debris

field approximately 450 feet wide and 1/4 of a mile long.

The team quickly makes a crucial find.

Well done, guys.

Well done, guys.

We did find both the cockpit voice recorder and the flight

data recorder which actually sped up

data recorder which actually sped up

that part of the investigation.

Analyzing the black boxes can be done quickly.

Analyzing the black boxes can be done quickly.

But on the ground, the search is arduous.

But on the ground, the search is arduous.

It was like, basically, a war zone,

because the airplane had crashed into this auto salvage yard.

because the airplane had crashed into this auto salvage yard.

There were still smoking automobiles, and car parts,

and airplane parts.

and airplane parts.

As teams on the ground continue to examine

the wreckage, investigators follow

the wreckage, investigators follow

up on other lines of inquiry.

Just spoke with the air traffic controller who

said that the pilots called in a center of gravity issue

said that the pilots called in a center of gravity issue

immediately after takeoff.

Emery 17, extreme balance problem.

Emery 17, extreme balance problem.

It sounds like a problem with the cargo.

The team checks to see if the cargo

The team checks to see if the cargo

was properly loaded.

This looks a little lighter than usual,

but it's well within the center of gravity limits.

but it's well within the center of gravity limits.

It's clear there was no problem

in load distribution.

in load distribution.

And there's no evidence that the load shifted after takeoff.

All of these restraints look just fine.

All of these restraints look just fine.

The thing is, if there wasn't a problem in the cargo hold,

The thing is, if there wasn't a problem in the cargo hold,

why were the pilots reporting a problem

with their center of gravity?

In search of a new lead...

OK.

...the team turns to the plane's

...the team turns to the plane's

cockpit voice recorder.

Set right.

Taxi checklist complete.

Taxi checklist complete.

When you listen to it, of course,

they're very professional.

They're doing their checklist items.

They respond appropriately and everything

They respond appropriately and everything

appears to be normal.

Airspeed's alive.

Airspeed's alive.

Alive here.

80 knots.

80 knots.

Elevator checks.

V1.

Rotate.

Watch the tail.

Watch the tail.

The captain is concerned that they're

pitching upwards too quickly.

We're going back.

OK.

OK.

What I'm trying to do is make the airplane's

position next to the elevator.

That's why I'm putting it in a bank.

Wait, wait, wait, wait, wait.

Wait, wait, wait, wait, wait.

What did he just say about the elevators?

The elevators, located on the rear

The elevators, located on the rear

of the horizontal stabilizer, control the aircraft's pitch.

When tilted upward, the airflow pitches the plane's nose up.

When tilted upward, the airflow pitches the plane's nose up.

When the elevators move downward,

When the elevators move downward,

the nose pitches down.

Investigators wonder if they malfunctioned.

Investigators wonder if they malfunctioned.

Your elevator isn't where you think it is, an airplane can

Your elevator isn't where you think it is, an airplane can

take off by itself.

They look to flight 17's

data recorder for information about the elevator's

performance.

performance.

Look at that, right there.

First officer, he pushed the column forward

First officer, he pushed the column forward

and the elevators did not respond.

Look at that.

Push forward.

Push forward.

Why was that elevator nose up when the pilot

was commanding nose down?

was commanding nose down?

Investigators re-examine

the recovered elevator assembly, looking for signs of failure.

the recovered elevator assembly, looking for signs of failure.

The elevator wasn't hydraulically powered.

Everything was analog, cables and pulleys.

Everything was analog, cables and pulleys.

Something strange about the pushrods

gets their attention.

Why isn't the right one damaged like the left?

Why isn't the right one damaged like the left?

The pushrod from the left elevator

is badly bent, as one would expect.

is badly bent, as one would expect.

But the rod from the right elevator is not.

The pushrod is a key part of the elevator mechanism.

When the pilot moves the control column,

When the pilot moves the control column,

the pushrod drives the elevator up and down.

So this is the rod in question.

And it would be attached with a nut and a bolt

And it would be attached with a nut and a bolt

and a cotter pin that would lock it in place.

This right pushrod wasn't even connected.

The absence of damage to the right side rod

The absence of damage to the right side rod

suggests that it detached before the crash.

suggests that it detached before the crash.

The big questions are, why?

And is this the cause of the crash?

Investigators need to find out...

Power!

...what caused an elevator

pushrod on Emery Worldwide flight 17 to disconnect.

pushrod on Emery Worldwide flight 17 to disconnect.

They check maintenance records to see

They check maintenance records to see

if any worked was performed on the right elevator assembly.

if any worked was performed on the right elevator assembly.

So it looked like the plane was in for a major overhaul

just three months before the accident.

The elevators, the control tabs, the rudder and its tab,

The elevators, the control tabs, the rudder and its tab,

all of that had been removed for overhaul

and then reinstalled during this very

and then reinstalled during this very

inclusive and invasive check.

During the scheduled maintenance,

During the scheduled maintenance,

the plane's elevator dampers were swapped.

They are a critical part of the horizontal stabilizer

They are a critical part of the horizontal stabilizer

and located near the pushrod.

One of the things that you always look at

is what was the last thing touched on the airplane.

is what was the last thing touched on the airplane.

So can you show me how you go about swapping

the dampers on this DC-8?

Yeah.

Yeah.

You reach over here.

Investigators speak with a mechanic

who performed the elevator damper swap on flight 17.

who performed the elevator damper swap on flight 17.

You detach it from the elevator.

One of the things that mechanics are always

One of the things that mechanics are always

looking for is an easier way to perform

their responsible duties.

their responsible duties.

That looks tricky.

You ever just disconnect the elevators

to get it out of your way?

Well, we're really not supposed to.

Well, we're really not supposed to.

Yeah, I know.

It's not hard to do.

An easy way to do it is to relieve the control tab

An easy way to do it is to relieve the control tab

by removing the bolt, the nut, and the cotter key

by removing the bolt, the nut, and the cotter key

and allowing the elevator tab to flex down.

That makes getting into this damper easier and quicker

to replace.

to replace.

Well, that was easy.

Do you ever do it that way on an actual job?

Do you ever do it that way on an actual job?

Like I said, we're really not supposed to.

Right.

Right.

You ever done this procedure before?

Well, I followed the manual.

A young mechanic, relatively inexperienced, working alone

on the weekend, doing something that he'd never done before,

on the weekend, doing something that he'd never done before,

nobody to ask for advice, and nobody to provide

him guidance or supervision.

him guidance or supervision.

It's pretty clear what happened.

The investigators believe that the mechanic

made a simple but fatal error during

made a simple but fatal error during

this routine maintenance.

I believe that when this worked was done,

I believe that when this worked was done,

he simply put the rod up, put the nut on it,

and forgot to put the cotter pin in the nut.

and forgot to put the cotter pin in the nut.

In the 12 weeks leading up to the crash,

In the 12 weeks leading up to the crash,

every time flight 17 becomes airborne,

the nut loosens a bit more until it falls off completely.

the nut loosens a bit more until it falls off completely.

The nut comes loose because there's nothing

holding it on, essentially.

holding it on, essentially.

And now the bolt starts to work loose.

80 knots.

80 knots.

80 knots.

On the night of the crash,

the right pushrod finally detaches.

The elevator column can no longer be controlled.

The elevator column can no longer be controlled.

As the plane accelerates along the runway, forces on the tail

As the plane accelerates along the runway, forces on the tail

increase.

The elevator control tab moves up.

The detached pushrod sticks.

The detached pushrod sticks.

And the elevator jams in the nose up position.

Watch the tail.

Watch the tail.

Power.

Power.

Pull up.

Don't sink.

Don't sink.

The jammed elevator seals the crew's fate.

The jammed elevator seals the crew's fate.

Power.

Come on.

In their final report, NTSB investigators

recommend that airlines keep better records

recommend that airlines keep better records

of all maintenance procedures to ensure

that no steps are missed.

Emery Worldwide is also singled out for responsibility.

Emery said, well, this is the first fatal accident

Emery said, well, this is the first fatal accident

we had in 50 years, basically, at that time.

Well, that's great.

Well, that's great.

But three pilots lost their lives because of a bolt,

a nut, and a cotter key.

a nut, and a cotter key.

But before the report is published,

the company is shut down.

the company is shut down.

At the end of the day, when it was all said and done,

the FAA moved in and pulled the certificate

the FAA moved in and pulled the certificate

and grounded the airline.

If you've got any sort of less than perfect maintenance

situation going on, you've got not only

situation going on, you've got not only

a dangerous airplane but, essentially, an accident

waiting to happen.

waiting to happen.

A twin turboprop goes missing in the North Sea.

And the ensuing investigation uncovers a criminal empire half

And the ensuing investigation uncovers a criminal empire half

a world away.

22,000 feet above the North Sea, Knut Tveiten

22,000 feet above the North Sea, Knut Tveiten

and Finn Petter Berg are flying Partnair flight 394,

a charter flight from Oslo, Norway

a charter flight from Oslo, Norway

to the German city of Hamburg.

124 decimal 55 by Partnair 394.

124 decimal 55 by Partnair 394.

How was dinner?

Delicious.

The two pilots are friends

The two pilots are friends

and both are close to retiring.

The plane they're flying is a twin prop Convair 340 580,

The plane they're flying is a twin prop Convair 340 580,

a popular plane for shorter routes like this one.

a popular plane for shorter routes like this one.

There are 50 passengers on board.

It's been an unremarkable flight so far.

But then...

...the plane experiences a sudden and violent shock.

It begins rolling.

Air traffic control realizes that not

Air traffic control realizes that not

only is Partnair 394 off course, it's falling from the sky.

only is Partnair 394 off course, it's falling from the sky.

Partnair 394, Copenhagen control,

please report new flight level.

Three, three.

Pull up.

Please report new flight level.

Pull up.

Air speed...

Air speed...

...radio contact lost report.

Please report new flight level.

Please report new flight level.

Flight 394 disappears from radar.

It's crashed into the sea, nearly 13 miles

north of the Danish coast.

north of the Danish coast.

Rescue teams find wreckage and bodies.

Rescue teams find wreckage and bodies.

All 55 passengers and crew are dead.

It's the worst loss of life

It's the worst loss of life

involving a Norwegian airline.

Investigators from the Norwegian accident

investigation board scrutinize sonar images of the seabed,

investigation board scrutinize sonar images of the seabed,

searching for wreckage.

searching for wreckage.

It was evident that the aircraft

had come apart in the air.

It hadn't hit the sea in one piece.

It hadn't hit the sea in one piece.

The plane's voice and data recorders

are retrieved from the seabed.

are retrieved from the seabed.

Both boxes are damaged.

Well, let's see what we got.

Auto system.

Armed two, three.

But for some reason, the CVR stopped recording

But for some reason, the CVR stopped recording

just before the plane took off.

While it had recorded their conversation on the ground.

But as soon as the engines were upshifted to normal RPM

But as soon as the engines were upshifted to normal RPM

for takeoff, it ceased operations.

So that was a disappointment to us.

So that was a disappointment to us.

The flight data recorder isn't any more help.

It's a basic analog model that failed

It's a basic analog model that failed

to record many of the parameters it was designed to log.

To use a metal foil strip that rotated and some marking pins

To use a metal foil strip that rotated and some marking pins

actually scratched on the metal surface, on the piece of metal.

actually scratched on the metal surface, on the piece of metal.

The recorder is sent to its American manufacturer

The recorder is sent to its American manufacturer

for further analysis.

In the meantime, investigators painstakingly

reconstruct the Partnair plane.

reconstruct the Partnair plane.

A reconstruction is like putting together a puzzle that

A reconstruction is like putting together a puzzle that

helps investigators focus the investigation on areas

that need to be looked at and helps

that need to be looked at and helps

prioritize the investigation.

The team notices heat damage on the tailfin.

The team notices heat damage on the tailfin.

Which means that it was flexing

Which means that it was flexing

because you develop heat where you're doing the fatiguing.

To learn why, investigators identify

the mechanic who inspected the plane

on the morning it crashed.

on the morning it crashed.

They learn from him that one of the plane's two main generators

They learn from him that one of the plane's two main generators

wasn't working.

And as two power units are required when flying,

the pilots improvised by using the auxiliary power

the pilots improvised by using the auxiliary power

unit, or APU.

unit, or APU.

We'll use the APU to power the left side AC system?

The APU is a backup generator

The APU is a backup generator

housed inside the rear fin directly beneath the tail.

Under normal circumstances, it's only used

Under normal circumstances, it's only used

to provide power on the ground.

APU is coming on.

APU is coming on.

When investigators inspect the APU,

When investigators inspect the APU,

they make an important discovery.

One of three mounts attaching the generator to the plane

One of three mounts attaching the generator to the plane

is broken.

That could have added considerable vibration

to the rear of the plane.

Did the increased vibration cause the aircraft's

mysterious plunge into the sea?

mysterious plunge into the sea?

To determine if vibration from the broken APU

brought down Partnair flight 394...

brought down Partnair flight 394...

...metallurgist Terry Heaslip tests the failed part.

My initial reaction was that the welding was bad,

My initial reaction was that the welding was bad,

was probably inappropriate.

was probably inappropriate.

I could see the impact markings and the progression markings

on it that showed that it did not fail

on it that showed that it did not fail

in this last accident flight.

The APU mount was broken long

The APU mount was broken long

before flight 394 took off.

Looks bad.

But how would that affect the plane's performance?

But how would that affect the plane's performance?

The APU is a large gyroscope having

The APU is a large gyroscope having

a tremendous amount of energy in it when it's rotating.

a tremendous amount of energy in it when it's rotating.

And if that energy is transmitted

to the surroundings, the fuselage, the structure,

to the surroundings, the fuselage, the structure,

it could impact the whole vibration pattern in the tail.

it could impact the whole vibration pattern in the tail.

With a broken supporting mount,

vibrations would have been magnified.

But investigators can't yet determine if that was

But investigators can't yet determine if that was

enough to bring the plane down.

As the recovered fuselage takes shape,

there's a promising lead.

there's a promising lead.

Two panels from the plane's tail fin are missing.

And we saw that the rudder had been

torn apart in two major pieces.

torn apart in two major pieces.

And some parts were missing.

In particular, the doors between the fin and rudder

were missing.

were missing.

The doors give mechanics

access to counterweights inside the rudder

that control its movement.

that control its movement.

If a rudder moves too violently from side to side,

the weights do so as well.

the weights do so as well.

We found enough pieces to show that,

that it was just pounding these doors.

that it was just pounding these doors.

And the first real components that came off were those doors.

And the first real components that came off were those doors.

Investigators conclude that a 22,000 feet, these doors

were knocked off because the counterweights

were knocked off because the counterweights

inside the rudder were swinging violently back and forth.

The question is, why was the tail moving with so much force?

The question is, why was the tail moving with so much force?

The APU, with the broken front shock mount, on its own,

The APU, with the broken front shock mount, on its own,

running in flight, would not cause

the aircraft to come apart and the tail to come apart.

the aircraft to come apart and the tail to come apart.

There had to be extra factors there for that to occur.

There had to be extra factors there for that to occur.

Hoping for answers, investigators

examine the plane's maintenance history.

examine the plane's maintenance history.

Where was the work done?

They discover that two months before the accident,

They discover that two months before the accident,

a mechanic replaced one of the four bolts

that connect the vertical fin to the plane's tail.

that connect the vertical fin to the plane's tail.

These four bolts are all that hold the tail to the fuselage.

These four bolts are all that hold the tail to the fuselage.

Remarkably, all four have been recovered from the wreckage.

Remarkably, all four have been recovered from the wreckage.

A close analysis provides a chilling finding.

A close analysis provides a chilling finding.

Of the four bolts, only one is a certified part.

Of the four bolts, only one is a certified part.

It worked out that the three

of the assemblies were not up to scratch.

of the assemblies were not up to scratch.

They were bogus assemblies.

Metallurgical analysis confirms that the three

Metallurgical analysis confirms that the three

faulty bolts were incorrectly heat-treated

when they were made.

when they were made.

Got something for me?

Mm-hmm.

They meet only 60% of the strength requirement.

They meet only 60% of the strength requirement.

They just weren't hard enough.

Unbelievable.

Unbelievable.

A picture of what happened to flight 384

has finally emerged.

The crash was caused by a tragic combination of events.

The crash was caused by a tragic combination of events.

On the day of the accident, the pilots

kept their plane operational by using the auxiliary power

kept their plane operational by using the auxiliary power

unit during flight.

APU is coming on.

They had no idea the APU mount was broken

and added considerable vibration to the tail.

and added considerable vibration to the tail.

To make matters worse, the three uncertified bolts

To make matters worse, the three uncertified bolts

that were holding the tail in place

added even more vibration.

If the two loose items start to vibrate

If the two loose items start to vibrate

in the same frequency, one vibration

in the same frequency, one vibration

is feeding the other one.

They're feeding each other and making

each other worse and worse.

The vibrations could have torn the plane apart.

The vibrations could have torn the plane apart.

The combined vibrations

caused the loose tail to swing violently,

caused the loose tail to swing violently,

jamming the rudder to the left and forcing the plane

jamming the rudder to the left and forcing the plane

into a steep left roll.

The roll is so extreme the tail's counterweights

knock the doors off.

Then the plane begins to break up.

Then the plane begins to break up.

The crew never had a chance.

Investigators conclude that Partnair flight 394 fell out

Investigators conclude that Partnair flight 394 fell out

of the sky because three of the four bolts holding the tail

on the plane were counterfeit.

on the plane were counterfeit.

The Norwegian report sends shockwaves

throughout the industry and raises a frightening question.

throughout the industry and raises a frightening question.

How many of the parts put in planes around the world

How many of the parts put in planes around the world

are bogus?

In the United States, the FAA takes

In the United States, the FAA takes

action and launches a major investigation

into parts suppliers.

The operation exposes a vast black market for spare parts.

In some cases, thousands of worn and inferior pieces

are made to look brand new.

are made to look brand new.

More than 100 parts dealers are arrested in the United States.

More than 100 parts dealers are arrested in the United States.

With every conviction, we were able to raise the level

With every conviction, we were able to raise the level

of awareness, not only of the problem,

but of the severe consequences if you

but of the severe consequences if you

want to risk somebody's life.

The Federal Aviation Administration

institutes a much more rigorous system

institutes a much more rigorous system

for documenting airplane parts.

And airlines now face criminal charges if they knowingly

And airlines now face criminal charges if they knowingly

accept unapproved ones.

We trust our maintenance people.

We basically literally put our lives in their hands

We basically literally put our lives in their hands

in every instance.

And 99.99% of the time, they live up to that trust.

And 99.99% of the time, they live up to that trust.

But every now and then, human nature takes over,

and we end up with something like these three accidents,

and we end up with something like these three accidents,

each one of which is just chilling to the bone.