Original subtitles

Good morning, ladies and gentlemen, this

is your captain.

I hope you had a good--

NARRATOR: Captain Stefan Rasmussen has been in love

with flying all of his life.

STEFAN RASMUSSEN: I got my first idea of flying

when I was a young boy.

NARRATOR: After learning to fly in the air force,

Rasmussen joined Scandinavian Airlines.

He seemed to, like, be the one who really enjoyed his job.

NARRATOR: On December 27, 1991, he's in command

of a state of the art DC-9.

The flight will take him to the very edge of his abilities,

as his engines fail and his plane falls out of the sky.

I was in a nightmare.

Stockholm Scandinavian 751, we are crashing into the ground

now.

NARRATOR: What caused the most baffling accident

in Sweden's history is nothing investigators

could have imagined.

What they finally uncovered will strain

Rasmussen's lifelong relationship with airplanes

to the breaking point.

I really felt that I didn't trust the aircraft.

PILOT 1: Ladies and gentlemen, we are starting our approach.

PILOT 2: We lost both engines.

FLIGHT ATTENDANT 1: Put the mask over your nose.

FLIGHT ATTENDANT 2: Emergency [inaudible]..

PILOT 3: Mayday, mayday.

PILOT 4: Brace for impact!

[inaudible]

MAN: He's gonna crash!

[music playing]

NARRATOR: It's two days after Christmas.

Stockholm Arlanda Airport is a mess of snow, slush, and ice.

Passengers boarding a mid-morning Scandinavian

Airlines flight to Copenhagen are finding

the cabin very uncomfortable.

INGRID ASTROM: It was really warm inside the plane

when we entered because there had been,

like, heaters on during night.

And I saw when the passengers embarked,

they also wanted to take off, like, jackets and shoes,

and-- because it was like a sauna.

Is it possible to turn the heat down now?

Just one moment.

NARRATOR: 34-year-old Ulf Cedermark

has been with the airline for four years.

He's the first officer on today's flight.

It was a light snowfall-- temperature was just below

freezing-- and light winds.

We were going to fly Stockholm to Copenhagen, and then

to Warsaw back to Copenhagen, and down to Barcelona that day.

It would be quite a long working day.

NARRATOR: Stefan Rasmussen has just finished

an exterior check of the plane.

The Danish pilot is in command this morning.

STEFAN RASMUSSEN: In those over 12,000, almost 13,000 hours,

I've been sitting in an aircraft,

I always felt that I put the aircraft on back of my--

like a rucksack.

And when we took lift on the wings, we melted together.

NARRATOR: The plane Rasmussen is strapping on today

is a nearly new DC-9, easily identifiable by its two

rear engines.

By now, everyone should know that door stays open.

Right.

NARRATOR: Even in the days before terrorist threats,

flying with the cockpit door open is unusual.

I found out that if we had the door open,

and they could see that there were human being in there,

they trust you.

NARRATOR: The winter weather has delayed this flight,

but Rasmussen won't compromise safety for schedule.

Where are we now with the de-icing?

TECHNICIAN (ON RADIO): The wings aren't quite done.

They've done the underside.

Now they're doing the top.

Thank you.

NARRATOR: Under Captain Rasmussen's instructions,

the ground crew had already de-iced the plane once.

Now they're giving it another pass.

ULF CEDERMARK: And it took a while.

But they had trouble getting rid of the snow on top of the wing.

And so we were slightly late for their push

back out to our runway.

NARRATOR: For Captain Per Holmberg, this kind of delay

is routine business.

He flies DC-9's for the airline.

A passenger this morning, he's scheduled to command

another flight later that day.

Finally, Scandinavian Airlines Flight 751

is cleared to proceed.

There are buildups of snow that the crew must avoid on the way

to the runway.

[scoffs] Would have been nice of them to clear the snow.

Oh, that would have made it too easy.

Approaching holding point runway 08.

AIR TRAFFIC CONTROL: Roger, Scandinavian 751.

You are cleared for takeoff from runway 08.

Spoilers.

ACTOR AS STEFAN RASMUSSEN: Armed.

Autobrake, take-off unarmed.

Runway update performed.

Checklist completed.

ACTOR AS STEFAN RASMUSSEN: Set power.

NARRATOR: Despite the winter conditions,

the take-off is routine.

V1, rotate.

Gear up.

Gear up selected.

[rattle]

STEFAN RASMUSSEN: When Ulf, he reached out for the gear,

I heard some things which was different.

NARRATOR: Just 25 seconds into the flight,

as the plane is climbing, there is a problem.

When you hear things that are different from the normal,

you get suspicious.

There was a really big roar in the aircraft,

like almost like an explosion--

boom.

[explosions popping]

INGRID ASTROM: There was another banging noise.

But I just thought, what is that?

I had never heard that before.

NARRATOR: It's obvious the source of the noise

it's the right engine.

It sounds serious.

I believe it's a compressor stall.

STEFAN RASMUSSEN: I took the right throttle

and moved a little back.

But there, it really became strange

because the engine performance increased

when I reduced the throttle.

It's like if you're sitting in your car,

and you were turning your wheel to the left

and the car is driving to the right.

You get confused.

INGRID ASTROM: We're not supposed

to call into cockpit now.

And then I thought, this is an emergency.

I have to call the captain.

NARRATOR: But Captain Rasmussen doesn't respond to the call.

He's too busy trying to figure out what's

going wrong with his plane.

I couldn't see anything on the instrument.

They were quite stable.

And they're quite normal range and no problem.

But I could hear those roaring every second.

NARRATOR: He searches for telltale signs of attack

or structural failure.

STEFAN RASMUSSEN: And I looked up at the cabin pressure,

because if you have a bomb or a freight door,

anything which is ripped off, that'll give a decompression.

NARRATOR: In the cabin, pressure levels are stable.

Have your seat belts fastened.

It's fine.

NARRATOR: But the crew has other concerns.

INGRID ASTROM: I saw the smoke.

And it smelt burnt.

What should we do about this?

NARRATOR: Just 3,200 feet above the ground,

the emergency escalates.

The right engine quits.

[engine winds down]

When we have flown a little over 1 minute,

the right engine just went down.

[beeping]

I had a very, very short moment of thinking

that I was in a nightmare and just dreaming.

I was confused.

I was really confused.

NARRATOR: 2 seconds later, the left engine also quits.

The plane is now powerless.

STEFAN RASMUSSEN: One engine dropped, and then

another engine dropped.

I thought that it wasn't true.

It wasn't true.

It wasn't real.

NARRATOR: Less than a minute and a half after takeoff,

the DC-9 begins falling from the sky.

INGRID ASTROM: And after that, it was complete silence.

And I think that was the worst moment for me,

just being in there and it's so quiet.

It was like a bird just sailing through the sky.

So then I started to get scared.

Engine relay.

NARRATOR: As the pilots try to restart their engines,

things get even worse.

The left engine erupts in flames.

ULF CEDERMARK: And I saw the exhaust gas

temperature was rising rapidly.

The max temperature was around 680 degrees Celsius,

and I saw it go above 800.

NARRATOR: A fire in the engine could spread

to the rest of the plane.

Should I pull?

NARRATOR: If Cedermark pulls the fire

extinguisher in the left engine, he will

never be able to restart it.

[beeping]

He pulls the handle to put out the fire.

From his seat, Captain Per Holmberg can see

that the crew is in trouble.

Flight 751 is now falling at a rate of 1,200 feet per minute.

But air traffic controllers at Stockholm Airport

have no idea the plane is in trouble.

Arlanda, Stockholm Scandinavian 751.

AIR TRAFFIC CONTROL: throttle morning, SK 751.

Climb to flight level 180.

ACTOR AS ULF CEDERMARK: We have problems with our engines,

please.

We need to go back to--

to go back to Arlanda.

AIR TRAFFIC CONTROL: 751, Roger.

Turn right heading to--

[static]

[powers down]

NARRATOR: Suddenly, the radio goes dead,

a result of the failed engines.

Only the right engine can provide power,

but it's now spinning too slowly to generate electricity

for the instruments.

ULF CEDERMARK: Without the engine,

you don't have any propulsion, so you will--

the only energy you have is your height.

NARRATOR: With time running out, the pilots of Flight 751

must find a way to restart the right engine or else crash

into the countryside below.

at 20 feet per second.

How can I help?

NARRATOR: Captain Per Holmberg, who

boarded the flight as a passenger,

becomes part of the flight crew.

He came out in the cockpit, and he said, is there

anything I can help you with?

I don't think I even said yes.

I said, just start the APU.

NARRATOR: If the auxiliary power unit can be launched,

it will bring back the radio and instruments.

ULF CEDERMARK: So I just handed him the emergency checklist

and started to focus on controlling the flight to see

that we were maintaining the speed and had the altitude

and that we were wings level.

He managed to start the auxiliary power unit.

So my flight instruments were supplied from that.

NARRATOR: But for some reason, Captain Rasmussen's instruments

don't come back online.

He managed to fly the plane basically by feel.

NARRATOR: Power is also restored to the cabin.

But it's small comfort to passengers, who now

know they're in extreme danger.

Stockholm air traffic control instructs the pilots

to return to the airport.

AIR TRAFFIC CONTROL: Scandinavian 751,

are you able to turn right heading

0-9-0, radar vectoring for 0-1.

NARRATOR: But the plane is now just

1,600 feet from the ground.

And First Officer Cedermark's attempts to resuscitate it

aren't working.

Roger.

We are maintaining our heading, but we are

trying to restart our engines.

NARRATOR: Making a 180-degree turn back to Stockholm

could be catastrophic.

I really had the feeling that if I

turned the aircraft at that time, we would have stalled.

When you're turning back, you are losing a lot of energy.

So the most safe thing to do is actually just to gold streets

and keep your wings level.

That means that you will use less energy of your altitude

so you can maintain your speed.

AIR TRAFFIC CONTROL: You can maintain 2,000 feet.

We are not able to maintain 2,000 feet.

We are descending.

We are at 1,600 feet and descending.

NARRATOR: Holmberg wants Rasmussen

to focus his attention on finding a landing spot.

Look straight ahead.

Look straight ahead.

He was screaming at Stefan just to look straight ahead

and watch the flight path.

Prepare for on-ground emergency.

On-ground emergency.

Bend down.

Bend down.

Bend down.

So we shouted "bend down" I don't know how many times--

bend down, bend down, bend down.

Keep your seat belts fastened.

NARRATOR: While passengers brace,

Rasmussen considers where to land his plane.

Look straight ahead.

STEFAN RASMUSSEN: And I had an idea that

on the northern direction could bring us out to the Baltic Sea,

which was at that time frozen.

And that's an excellent runway.

NARRATOR: But instead, he finds himself gliding powerlessly

over a dense forest.

STEFAN RASMUSSEN: I saw that green area.

And I saw that little light spot in the middle of the forest.

But that really looked short.

Steer right.

Steer right.

NARRATOR: Just 500 feet above the ground,

Captain Rasmussen lifts the plane's nose to slow it down,

hoping to soften the crash landing.

STEFAN RASMUSSEN: Pine trees, from the top

they look very soft.

I could use the trees as almost like a pillow.

Should I lower the landing gear?

STEFAN RASMUSSEN: Yes.

Gear down.

Bend down and hold your knees.

INGRID ASTROM: I prepared myself for a hard impact.

If it's an emergency landing, we have no engines,

I just thought, this is going to be a hard landing.

Stockholm Scandinavian 751.

We are crashing into the ground now.

ULF CEDERMARK: I wasn't afraid until we

were flying into the trees.

Then I was scared, and I knew we were not going to make it.

STEFAN RASMUSSEN: I didn't thought I should die.

I knew I should die.

I-- I made my prayer to god.

[metallic screech]

[crunch]

[impact]

And then a moment after, we were--

we were-- we were in a strange world.

[wind whooshing]

INGRID ASTROM: After we have come to a complete stop,

I feel the smell of airplane fuel.

I thought, OK, we're going to explode.

And I look around, and I see the snow because there was

a big crack in the airplane fuselage

just in front of the aft galley.

And you could just walk down on the ground.

STEFAN RASMUSSEN: Everything was quiet.

And I woke up.

It might only have been a split second or so.

ULF CEDERMARK: I was afraid that my spine

was broken, that I was--

wouldn't be able to walk again.

So I remember I was sitting there,

and I was moving my toes and my feet,

just to see if I could have control over them.

I had a pain in my hand because I had broken a bone in my hand.

And I was bleeding heavily from my forehead

so I was trying to get clear of all the blood that

was coming down in my eyes.

And Stefan told me that we had to get out of the aircraft.

NARRATOR: After plowing through over 400 feet of pine forest,

the pilot's fear is now that the broken aircraft

could catch fire.

[coughing]

Dozens of passengers escaped through the breaks

in the fuselage walls.

But Captain Per Holmberg has been knocked

unconscious by the crash.

INGRID ASTROM: It all went so fast that, like, no one could

take in, like, what happened.

So I tried to stay with a group of passengers I had there.

But I just knew the feeling also that we had to wait a long time

for the rescue teams.

Help will be here soon.

NARRATOR: Fortunately, no fire materializes.

But because they removed their winter clothing

while boarding the sweltering plane,

many passengers are starting to freeze.

Most people were just standing in their shirts, t-shirts,

very, very little clothes.

Few didn't even have shoes on.

NARRATOR: They are now at risk of hypothermia.

INGRID ASTROM: So I focused on being caring.

Maybe I did it for my own sake also.

I needed a hug also.

It was comforting to, like, comfort someone else.

[shaky breathing]

NARRATOR: The wreckage of Scandinavian Airlines Flight

751 lies just over 9 miles northeast

of Stockholm Arlanda Airport.

The fuselage is broken into three pieces.

In the chaos of the moment, nobody knows how many people

have been killed in the crash.

Rescuers arrive within minutes and attend

the freezing survivors.

They pull Captain Per Holmberg from the cabin unconscious.

ULF CEDERMARK: He landed on the wall at impact,

and he skidded down on the wall to the floor at impact.

So he was quite badly damaged.

He cut his eyelid, and he also got

his collarbone that was broken off,

so his shoulder was in front of him.

NARRATOR: 92 of the passengers have sustained injuries.

Only eight are considered serious.

But when the crew conducts a headcount,

they're stunned to learn that out of the 129 people

who boarded Flight 751, not a single one

was killed in the crash.

INGRID ASTROM: Everyone survived.

It was like a shock just to take in.

So I was the happiest captain in the world.

We were all alive.

That was a great moment.

as the Swedish Accident Investigation Board, or SAIB,

takes charge of the case.

Scandinavian Airlines alerts its own Investigators,

dispatching Tore Hultgren to head up its team.

TORE HULTGREN: It's most unusual that the plane

crashes in a wooded area and everybody survives.

I've never heard of it before.

The police kept everybody off the site itself.

There was a cordon around the aircraft about 100 meters.

We had the complete aircraft.

Nothing had burned.

And we had lots of good data.

NARRATOR: Henrik Elinder from the SAIB

gets to work on the evidence.

HENRIK ELINDER: And we all started

to plan the documentation of the accident site, which means

photographing all the final approach through the woods,

you know, and to take photos of all the parts that

were spread all over the place.

NARRATOR: The two black boxes which

record cockpit conversations and store flight

data are recovered immediately.

Investigators speak to survivors.

Everyone tells a similar story.

Would you mind telling me what you saw and heard?

NARRATOR: Loud booming sounds from the engines moments

after the flight began, smoke in the cabin,

and finally, the entire loss of power and an engine on fire.

You have a twin-engine aircraft,

and you are really not supposed to lose

both engines at the same time.

NARRATOR: The Pratt & Whitney turbofan engines

are sent to a Scandinavian Airlines repair

shop for a closer examination.

Investigators are eager to speak with Captain

Rasmussen about the incident.

But to their dismay, Scandinavian Airlines

takes him to the mead first.

The first question, what did you think when both engines

refused to function?

It'll take me an awful long time to tell you all that.

HENRIK ELINDER: The normal case is that the key witnesses,

like the crew and so on, should be

kept in quarantine until they meet the investigation board.

NARRATOR: European media celebrate Captain Stefan

Rasmussen as a hero for landing the DC-9 without engine power.

But Investigators consider the possibility

that he or his copilot had made errors that caused

the crisis in the first place.

The honor and the glory always rests with the captain,

but so does also the mishaps.

STEFAN RASMUSSEN: I knew that being a person where--

in the spotlight of the press would

be a quite different situation.

And I said to myself, the only thing you can do now

is to give them all the story and then pray

that they will find the reason.

Lift.

NARRATOR: Lars Lindberg is an investigative representative

for the Swedish Airlines Pilot Association.

He examines the wreckage for signs

of mechanical or structural failure.

We knew both engines had failed for some reason.

So we was concerned what was the background for something

like that to happen.

The first time I saw the engines in the workshop,

I was surprised.

Is this all they found?

There was a number of parts that were completely missing.

And this was something we hadn't seen before to this extent.

NARRATOR: To find out what happened,

investigators must find the missing pieces,

which now lie somewhere in snow-covered fields

and forests.

A close study of Scandinavian Airlines Flight 751'S engines

reveals exactly which pieces are missing.

LARS LINDBERG: Parts of this aircraft

was shedding parts from both engines.

And then what you do is you go further in,

and you document everything, and you try to find the root cause,

and see how it all comes together.

NARRATOR: The missing pieces could hold the key

to discovering why both of the plane's engines

quit within seconds of each other.

But they could be anywhere along the 9-mile route the plane

covered during its short flight.

They must be found.

Investigators use the flight data recorder

to map the plane's journey and determine where

engine parts may have fallen.

After scouring the snow-covered fields along the plane's path,

the recovery team finds 500 fragments, just

a fraction of what's missing.

Many are very badly damaged.

Some of the titanium blades actually

seem to have been on fire.

LARS LINDBERG: You have this titanium

fire inside both engines, both the right and the left engine.

And this titanium fire is a very unique occurrence.

It's requiring very, very high pressure

and very high temperature for a titanium blade to catch fire.

NARRATOR: Investigators dig deeper into the cause

of the engine trouble.

The left engine's fuel line is badly dented.

It was obviously hit by a fast-moving piece

of metal inside the engine.

The impact caused it to rupture.

When this part got dislodged, it

went out and hit the fuel line.

And that fuel line cracked, sprayed

fuel onto the hot engine.

NARRATOR: The engine was clearly coming apart during the flight.

It sounds serious.

NARRATOR: The discovery explains the fire into left engine,

and why so many pieces of it were found

so far from the crash site.

But Investigators are left wondering why the engines

broke up in the first place.

A major clue comes from passenger and crew testimonies,

which told of repeated booming noises

before the left engine caught fire.

The cockpit voice recorder picked up these sounds.

So you can hear that.

Then we could correlate that with when the damage occurred.

You can see that on the flight data recorder.

NARRATOR: The sounds are familiar to investigators

and leave no doubt.

The DC-9's engines began surging shortly after takeoff.

Jet engines rely on a steady stream of air for combustion.

A series of fans move incoming air through various stages

of compression.

But when that flow is disrupted, fuel at the rear of the engines

ignites violently and shoots forward.

That's the surge.

You can have a small surge, and you can have a large surge.

And you can have the complete surge on the whole engine.

It sounds serious.

[high-pitched whir]

LARS LINDBERG: This surge process was very violent.

So after a very short time, we had an aircraft

with two engines that could not be restarted that didn't

generate any thrust.

Basically, you had a giant glider at that point.

blades from the front of the engines

explains why they were surging.

They're badly dented.

The damage would have prevented them from effectively directing

air to the rear of the engines.

This damage that twisted the fan blade started this process.

You got this disturbed air in the fan.

You got this rotating fan stall that then triggered

this whole breakdown-- the compressor surge,

and then the whole process that led

up to the dual engine failures.

NARRATOR: But what exactly mangled the blades?

There are ways to tell.

If it comes from a stone, rubber, ice, and so on,

you can see it on the shape of the damage.

The ice causes very specific damages.

It's sort of like a soft dent.

NARRATOR: Analysis of dent patterns on the fan blades

is conclusive.

They were struck by ice.

snow Investigators want to find out where

the ice could have come from.

We have the data for the 24 hours leading up to the crash.

NARRATOR: They know Stockholm had been hit with rain and snow

in the hours before Flight 751 took off.

HENRIK ELINDER: It was a situation with a temperature

around 0 degrees.

It was a drizzle snow rain in the morning.

NARRATOR: They learned that the DC-9 arrived

from Zurich the night before with the fuel

tanks more than half full.

TORE HULTGREN: They had quite a large amount of reserve fuel,

diversion fuel, in their wings.

The fuel in the wing tanks were close to minus 20 degrees

Celsius.

NARRATOR: The conditions that night

were ideal for the formation of clear ice on the wing surface.

And here you had very, very cold fuel on the top wing skin.

And as the temperature dropped during the night,

it went to snow, and rain, and finally snow.

So there was a layer cake--

ice at the bottom, slush, and snow on top.

But 10 inches total on top of the wings in the morning.

NARRATOR: Responsibility for de-icing the plane ultimately

falls on the captain.

Rasmussen insists he was aware of the overnight buildup.

Investigators wonder if the pilot

did all he could to ensure his plane

was completely free of ice.

Rasmussen claims he instructed technicians

to de-ice the plane thoroughly.

I did a walk around with the aircraft.

It was cold.

It was frosty.

NARRATOR: Noticing that there was still frost on the wings,

the head technician ordered a second round of de-icing.

I was really convinced that the aircraft was clean.

And so was he.

So was he.

STEFAN RASMUSSEN (ON RECORDING): Where

are we now with the de-icing?

TECHNICIAN (ON RECORDING): The wings aren't quite done.

They've done the underside.

NARRATOR: The cockpit voice recorder

backs up Rasmussen's testimony.

STEFAN RASMUSSEN (ON RECORDING): They've got it

good and clean under the wings?

TECHNICIAN (ON RECORDING): Yes, yes.

TORE HULTGREN: De-iced the aircraft once, and looked at it

and then said, once more.

And they de-iced a second time.

NARRATOR: In fact, 225 gallons of fluid

were sprayed on the aircraft.

But the fluid may have been faulty--

not potent enough to melt the thick layer

of ice that had accumulated on the wings overnight.

Technicians test samples of the fluid

used to de-ice Flight 751.

TORE HULTGREN: They found no discrepancies.

There was nothing wrong with any of the fluids used.

NARRATOR: But when investigators interview the maintenance crew

that worked on the plane, they begin

wondering if the de-icing team was thorough enough

in their efforts.

The ground crew insists that after they sprayed the wing,

it appeared to be clean, but that appearance was deceptive.

It looked perfect because the clear

ice on top of the fuel tanks, you cannot see the clear ice.

NARRATOR: A technician inspected the front of the wing

and found no ice.

He couldn't have known that there was ice further back out

of his reach.

TORE HULTGREN: No provisions for stairs or anything

that he could use to get up on the wing

at the de-icing platform.

It looked shiny and nice, couldn't see any ice on it.

But still, there was maybe an inch of ice on top of the wing

when the aircraft took off.

NARRATOR: As soon as the plane took flight,

the ice became a problem.

TORE HULTGREN: On this aircraft, the engines are

positioned behind the wings.

And as the aircraft rotated, and the wings bent in order

to take the weight of the aircraft,

this ice in the wing roots loosened, and it

sucked right into the engine.

NARRATOR: The ice damaged the fan blades

at the front of the engines and ultimately

caused them to begin surging.

TORE HULTGREN: Nobody really expected this would happen

or could happen.

But it did.

NARRATOR: When ice breaks off the wings during flight,

it doesn't pose a problem for most aircraft.

But the placement of the DC-9's engines

leaves them more susceptible to being struck.

The Pratt & Whitney engines on Flight 751

were designed to withstand this type of ice ingestion.

Something else must explain the disaster.

Investigators know that the wrong reaction by a pilot

can make surges worse.

They combed through the flight data

to see what these pilots did when the emergency struck.

The first thing you do when you have

a surge, if you recognize is that a surge,

is that you reduce power.

NARRATOR: Captain Rasmussen claims he did just that.

Of course, you just pull the throttle back,

and then you help with the balance

between the incoming fuel, incoming air.

And that was exactly what I did.

NARRATOR: But the flight data recorder

tells a different story.

Why is the engine power increasing?

NARRATOR: It clearly shows that in the moments after the surge,

thrust was reduced, but then seconds later, it was

increased to beyond full power.

Yeah, it didn't add up because the RPM was increasing to 110%.

And the throttle position was moving.

It shouldn't be.

The only thing that could move the throttles [inaudible]

was the pilot's hand.

NARRATOR: But if Rasmussen didn't push the throttles

forward, something else did.

It would explain the captain's confusion

as his engines began to surge.

As a pilot, when you've gone through the training,

you've done all your emergency training,

you've been through the simulator,

and now you have a system that is doing something

that you don't expect, it's very confusing.

investigators can find no possible explanation

for the increase in thrust.

LARS LINDBERG: The frustrating part with the investigation

was that we could not figure out why the system did what it did.

NARRATOR: Then almost two months after the accident, the plane's

manufacturer provides the answer.

The culprit is something called "automatic thrust restoration."

ACTOR AS LARS LINDBERG: It's brand new.

It automatically increases the thrust during the climb.

NARRATOR: Swedish authorities learn that Automatic Thrust

Restoration, or ATR, was recently

introduced as a safety feature on Scandinavian Airlines

planes.

It existed because the FAA had discovered some pilots were

throttling back considerably while taking

off and landing to reduce noise over residential neighborhoods.

The ATR was designed to make it impossible for them to throttle

back to dangerous levels.

So as soon as he powered back, the system kicked in.

NARRATOR: Investigators learned that when Rasmussen reduced

power to clear his engine surge, the system read this

as a dangerously low power setting

and pushed the throttles forward.

The increased thrust made the surging worse until the engines

destroyed themselves.

The investigation concludes that the pilots had taken

the right steps to clear the surge

and prevent the catastrophe, but the computer

code which governs the ATR undermined their efforts.

A strip of 0's and 1's caused the throttles to move

and caused the engines that were stalling,

because they already got too much fuel, got even more fuel.

And they went into self-destruct, both engines.

In a few seconds, they're both totally destroyed.

[creaking]

[metallic screech]

[crunch]

[impact]

NARRATOR: The system was so new to Scandinavian Airlines

that nobody there had even heard of it.

LARS LINDBERG: And it was confusing for everyone

because we didn't know about the system.

We didn't have information on the system.

SAS didn't know the system existed on their aircraft.

We hadn't bought that modification.

And it was sneaked in via another system.

NARRATOR: Because he didn't know about the ATR,

Rasmussen was unaware that he could only save

his plane by switching it off.

News that the automatic thrust restoration

was responsible for the accident proved both a blessing and

a curse for Captain Rasmussen.

It eliminated any notion that he had made a mistake.

STEFAN RASMUSSEN: When I got that message,

I was really released.

It was like winning in the lottery.

It was-- because I was so happy.

Because then I could explain why I was in that total cone

of confusion.

NARRATOR: But the fallout would ultimately destroy

a love affair and end a career.

On October 20, 1993, the Swedish Accident

Investigation Board releases its report

on the crash of Flight 751.

It determines that the actions of Captain Rasmussen and First

Officer Cedermark contributed to the safe outcome

of this incident.

And although investigators question Captain Per Holmberg's

decision to enter the cockpit in the first place,

they do praise his contribution.

This crew flew until they stood still on the ground.

They never gave up.

They never gave up.

They didn't give an inch.

NARRATOR: The investigators put much of the blame

for the accident on Scandinavian Airlines

because their procedures for checking for clear ice

were inadequate.

I believe it's a compressor stall.

NARRATOR: The report also condemns the fact

that the pilots didn't know about the automatic thrust

restoration and how it would act in a surge situation.

LARS LINDBERG: If the ATR system hadn't been there,

if the throttles hadn't moved forward,

there wouldn't have been an accident.

It was a bit strange that we didn't have

all the documentation available to us

so we knew what we could expect if something like this

would happen.

NARRATOR: In the wake of the crash,

Scandinavian Airlines started training its pilots

how to use the ATR system.

They also implemented steps to ensure airplanes don't take off

with clear ice on the wings.

TORE HULTGREN: We changed all the procedures.

We provided stairs for the mechanic.

And we made it a requirement to go up on top of the wing

and touch it with your hand to verify after de-icing.

NARRATOR: After healing from his injuries,

First Officer Ulf Cedermark returned to the cockpit.

ULF CEDERMARK: I didn't feel the responsibility that I wouldn't

be able to do my job again.

Whatever happens, I know that I still can

see things for what they are.

And I still love doing my job.

And if something bad happens, I can deal with it.

NARRATOR: But Stefan Rasmussen's return

proved far more difficult.

Set power.

STEFAN RASMUSSEN: After I'd heard

from a high-skilled psychologist,

we talked about getting in the air again.

He knew that that would be a hard decision to take.

Gear up.

[beeping]

Fire drill.

[breathes heavily]

NARRATOR: After time in the simulator,

Rasmussen couldn't regain confidence in his plane.

Sorry, guys.

STEFAN RASMUSSEN: In a disaster situation, in a crisis,

is that you have optimized the teamwork

between man and machine.

I really felt that I didn't trust the aircraft.

TORE HULTGREN: The pilot tends to take the responsibility

for all that went wrong.

Too much of the glory and also too much of the responsibility.

NARRATOR: With the right counseling, about 90%

of pilots involved in an accident

are able to continue flying.

Even though Captain Rasmussen received treatment,

his career ended with the crash of Flight 751.

Taking that decision to leave aviation

as pilot was like having your--

your highest love and come to the conclusion

that you have to kill her.

I had many hours, many missions of happiness in an aircraft.

And I loved my passengers, I loved my aircraft so much.

So I said, that's it.

[music playing]

I never regret it.

Never.

And I think I was right.