All language subtitles for Air.Disasters.S06E07.Helicopter.Down.1080p.PMTP.WEB-DL.AAC2.0.H.264-maldini_track3_[eng]

Narrator: 3,300 feet
above the frigid North Sea,

disaster strikes.

A helicopter is crippled
in the middle of a sudden storm.

The pilots struggle for control

as it sinks helplessly
toward the sea.

They are far from land...

Pilot: Mayday, mayday,
56 Charlie.

Narrator:
...off the radar screens.

No one knows
exactly where they are.

In the days that follow,

investigators
search for the truth

hidden in this tangled wreck.

The cause of the crash is
a shock for all those involved

and reveals a hidden danger

that reaches far beyond
the North Sea.

Flight Attendant:
Ladies and gentlemen,
we are starting our approach.

Pilot: We lost both engines!

Flight Attendant:
Put the mask over your nose.

Emergency descent.

Pilot: Mayday, mayday.

Flight attendant:
Brace for impact!

Controller: I think I lost one.

Man: Investigation starting...

Man: He's gonna crash!

Narrator: January 19, 1995.

Commander Ced Roberts
and first officer Lionel Sole

work for Bristow helicopters
in Aberdeen Scotland.

Ced Roberts:
I'll just sign this tech log,
and I'll see you upstairs.

Narrator: Their job
is to ferry oil workers

out to the oil platforms
in the North Sea.

Man: Cheers, gentlemen.

Narrator:
By mid-morning, they've
completed one trip already

and are getting ready
to head back out.

Their helicopter
is Super Puma 56 Charlie.

While it's being checked out
and refueled,

flight officer Sole
checks the flight logs

and commander Roberts
goes through the weather reports

which are updated
every two hours.

Lionel Sole:
The weather's okay.

Good for January.

Narrator:
This is where they're heading:

The North Sea.

The discovery of oil here
in the 1960s

was a shot in the arm
for the British economy.

Brent crude,
as the oil is known,

is a light, sweet crude,

ideal for turning into gasoline,

and its price is a benchmark
on the international oil market.

It helped turn Aberdeen,

the Scottish port city
closest to the oil rigs,

into a boomtown,

the European oil capital.

All the leading oil companies
have offices here.

The city is focused on getting
the black gold ashore.

Because the rigs
are so far offshore

and the weather
so unpredictable,

helicopters are the only way

to reliably ferry workers
back and forth.

Hundreds of thousands of people
make the trip every year.

The Super Pumas

are the workhorses
of the North Sea oil industry.

Used around the world
by industry and military,

they are durable, tough,

and made to withstand
the elements.

There are more
of these helicopters

flying offshore here

than anywhere else in the world.

The passengers heading
to the platforms today

gather in the heliport's
departure lounge.

They all work for
the Texas company Marathon Oil.

The North Sea
has scores of oil fields.

They are divided up
between several countries,

including England and Norway.

The governments
then sell the rights to drill

to a variety of oil companies.

Marathon operates
three platforms

in the so-called Brae field:

Brae East, Bravo, and Alpha.

North Sea oil platforms are like
cities that never sleep.

They stand on the seabed,

held up by enormous legs
of either metal or concrete.

Out here,
you're surrounded by the sea,

with nowhere to go.

The weather is often horrible.

And the work on a rig can be
rough, dirty, and dangerous.

It's difficult
to find and retain

the skilled workers needed
to pull the oil from the sea,

so the platforms are built
to keep the workers happy.

Movies, Internet cafes,
gym equipment, and great food

are provided by management to
ensure the men are entertained.

During 12-hour shifts,

workers handle heavy equipment

and deal with great heights...

Or great depths.

But there are strict rules, too.

To protect the safety
of everyone on board

there's no drinking,

and smoking
is severely restricted.

Man: Mayday!

Explosion and fire
on the piper platform.

All personnel abandon.

Narrator: One of Britain's
worst disasters

happened in
the North Sea oil fields.

In 1988,

on occidental petroleum's
piper Alpha platform,

gas exploded
and set fire to oil.

167 men died.

The potential for disaster
is never very far away.

But on this January day,

the marathon oil workers
prepare as they always do.

All 16 are scheduled
to spend two weeks

on marathon's Alpha platform,

followed by two weeks off.

To these men, getting to work
has become routine.

But getting a ticket
on this flight

calls for something
a little out of the ordinary.

None of them are permitted
to board a helicopter

without first
going through this:

Helicopter
underwater escape training.

Their lives may depend

on knowing how to get out
of a submerged helicopter

or off an oil rig,

and knowing what to do

once they find themselves
in the chilly North Sea.

Several accidents
over more than 20 years

have driven home the point:

Training may help
a worker survive.

Before they set off
on every flight,

they must watch the video:

How to behave if there's
an emergency on your flight.

They've all seen it
a thousand times.

Man on video: In an emergency,
if time does not permit,

just tighten your lap strap
and brace for impact.

To exit through the windows,
pull the red tab

to completely remove
the rubber seal...

Narrator: The passengers
fasten their survival suits.

Made of gore-Tex,

these dry suits
won't keep them afloat,

but are supposed
to keep the water out

if the workers
are thrown into the sea.

Man on video:
...the forward windows.

Narrator: Their bright colors
are also designed

to make rescue easier.

The trip
to the Brae Alpha oil platform

is 143 miles.

If all goes well, it will take
a little more than an hour.

Then, 120 miles out,

they'll reach an area
called the gate.

That's where
all the helicopters split up

and go their separate ways to
the individual oil platforms.

Brae Alpha is about 25 miles
from the gate.

For part of the journey,

the radar operators at
air traffic control in Aberdeen

will not be able to see them.

John Miller: The reason why
we lose low-level radar coverage

out over the North Sea

is in essence
because the earth is round.

As a helicopter's flying
outbound to an oil rig,

it's actually following
the curvature of the earth.

Narrator: But radar pulses
travel in straight lines,

which means that as they travel
further and further away,

a gap opens up between
the surface of the earth

and the radar waves.

Miller: If an aircraft
flies into that gap,

then it will disappear
from radar.

In the case of Aberdeen,

a helicopter operating
at about 2,000 feet

will disappear into that gap
at about 80 miles.

Narrator: It's a black hole

which Super Puma 56 Charlie
is now entering.

The helicopter
and the 18 men on board

are over halfway
to the oil rigs.

From this moment on,

no one knows
exactly where they are.

En route
to the Brae Alpha oil rig,

the Super Puma crew
becomes concerned

about what they see
on their weather radar.

The forecast called
for scattered clouds,

but the weather
is changing fast.

Sole: What do you think
about this cloud?

Roberts: It's quite thin.

Sole: Yeah, but look.
We're getting some cumulus, too.

It's quite small.
About 100 yards across?

Roberts:
Yeah, but it's developing a bit.

Narrator:
Cumulus are puffy white clouds,

like balls of cotton wool.

They're beautiful to look at
and usually harmless.

They only last
between 5 and 40 minutes.

But helicopter pilots prefer
to go above them if possible

because the air inside and below
gets very bumpy.

Roberts:
Let's try to climb above it.

Go to 5,000 feet.

Sole: Right.

Oh, look, there's
a line of them...

All along the route,
exactly where we're going.

Roberts: Yeah, we're not
gaining anything by this.

Let's drop back down
to 3,000 feet.

Sole: Right.

Narrator: So far, the weather
is nothing to worry about.

But over the North Sea,
it can change suddenly.

This corner of Europe

is where the warm winds
from the Atlantic

meet the icy blasts
from the arctic and Siberia.

The warm water vapor
condenses into clouds, cools,

then sinks.

It creates strong winds pushing
the huge masses around.

Friction caused by this motion
can create electricity,

and that electricity
can end up as lightning.

What starts out as a placid day
can end up as a violent storm.

It's now one hour after takeoff,

and 56 Charlie
is approaching the gate,

the point where helicopters
begin their descent

to the individual oil platforms.

They are 25 miles
from their destination,

and the weather
is getting worse.

Sole: Brae traffic,
56 Charlie,

120 miles on the zero 56 HMR.

Narrator: They make contact
with Brae traffic watch

located on one
of the oil platforms.

It handles all the comings
and goings of helicopters.

But Brae traffic
doesn't have radar.

It has to rely on the pilots
to tell them where they are.

Sole: Leaving 3,000 feet.
Would you take the flight watch?

Controller: Roger, 56 Charlie.
I have your flight watch.

Sole: Aberdeen information,

Bristow's 56 Charlie
at 120 miles,

leaving 3,000 feet.

Brae has the flight watch.

Controller:
Roger, 56 Charlie.

Continue with Brae traffic.

Narrator: Suddenly,
the weather has changed.

Instead of the harmless fluffy
balls of cotton wool,

a line of dangerous
cumulonimbus clouds

is now blocking their path.

They rise up
like huge white mountains

more than 30,000 feet--

far higher
than the chopper can fly.

Underneath
they are dark and menacing.

Pilots try to avoid them
at all costs.

Inside, gusts of wind can reach
up to 60 miles an hour.

The turbulence
can make the flight unpleasant,

but that's only part
of the danger.

Alex Hill: The cumulonimbus,

that's the granddaddy
of all clouds.

It stretches from round about
a thousand feet at its base

all the way up to
28,000, 30,000 feet.

They are
the most dangerous clouds

that aircraft can come across,

particularly small aircraft
like helicopters.

Within a cumulonimbus,

you're going to find
severe turbulence,

you're going to find icing,
you're going to find heavy rain,

and of course you're going
to find lightning.

If you're flying a helicopter,
that's not where you want to be.

Narrator: Lightning is one
of the most powerful forces

of nature.

Around the earth,

it strikes an average
of 100 times every second--

each strike with the power
of up to a billion volts.

Aircraft can't
completely avoid it.

On average, every passenger jet

will be hit once a year
by lightning.

But the design of the planes

keep them
from being badly damaged.

Their bodies are
traditionally made of aluminum,

which is a good conductor
of electricity.

The lightning passes harmlessly
along the fuselage

and exits from the tail.

Helicopters use the same type
of design to keep safe,

and they need it
in the North Sea.

With such stormy weather
and so many helicopters,

lightning strikes
are inevitable.

As they begin their descent,

the Super Puma
enters the line of clouds

that stands in their path.

Sole: Bits of cloud
coming up here.

Roberts: It's ok.
It's still green.

Just carry on through that.

Narrator:
Green on the weather radar

means there's rain,

but it's not heavy enough
to worry about.

But soon, the weather
gets more intense.

They begin to be pelted by hail.

Sole: Hey,
where'd this come from?

Roberts: It's coming in
through the vent.

Sole: It's like being
inside a bean bag,

swamped by polystyrene balls.

Roberts: It's so thick.

How come the engines
are still running?

There can't be
any air left out there!

Sole: No.

Narrator: Now another problem.

Sole: We've got a hard-over
on the ice detector.

Roberts: It's probably
just an ice pellet

stuck in the probe.

Sole: Right.

Narrator: The helicopter
has an ice detector--

a probe outside the craft

which is supposed
to tell the pilots

if there's ice on the blades.

But they think
it's become jammed with ice

and is giving a false reading.

And then...

Disaster.

Sole: Bloody hell!
Roberts: What was that?

Sole: Lightning. I saw it.

Well, this is bad.

There's something
very, very wrong with this.

We'll have to go down,
I'm afraid.

Narrator:
The helicopter is damaged.

But they don't know how badly.

The entire body
is shaking and vibrating.

The crew's first instinct is to
get down to a lower altitude

in case the worst happens
and they fall out of the sky.

Roberts: Mayday, mayday!
56 Charlie.

Lightning strike.
Severe vibration.

Mayday! Mayday!

Narrator: 25 miles away,

another helicopter is about to
leave a different oil platform.

Commander Brian Backhouse

is loading passengers
on 56 Bravo

and preparing to fly back
to Aberdeen.

Brian Backhouse:
That's everyone. All set.

Narrator:
Suddenly, the loading officer

hears Lionel Sole's
mayday call on his radio.

Sole: Mayday! Mayday!
56 Charlie.

Lightning strike.

Man: Hear that mayday?
56 Charlie!

Backhouse:
Gentlemen, my apologies,

but we have to disembark you.

We have an airborne emergency
on a sister aircraft.

Narrator: Backhouse hurriedly
unloads his passengers.

He intends to help if he can.

Meanwhile,
a gale is steadily building,

with winds
of up to 60 miles an hour.

The seas are mounting.

The crew of 56 Charlie

are struggling to keep control
of their crippled helicopter.

After the initial flash, though,

the situation hasn't gotten
any worse.

The Grampian Freedom
is a standby ship

positioned near the oil rigs.

To give the oil workers
a way to escape

in case anything goes wrong.

Her skipper, John Macinnes,

hears the helicopter's
distress call.

John Macinnes:
We increased the speed

to full speed ahead.

Everybody was informed
about the vessel

and told to get ready for
survivors to be taken aboard.

Narrator:
Back on the Bravo platform,

what was a routine flight
for Brian Backhouse

is about to become
a rescue mission.

He intends to find
the stricken helicopter

and nurse it to safety.

If it crashes into the sea,

he'll direct rescue ships
to the spot.

But they're not sure
where to go.

Backhouse: Let's go to the gate
and proceed from there.

Narrator: At least
they'll have a starting point.

The Grampian freedom doesn't
know where to go either.

They're getting
conflicting messages

about where 56 Charlie is.

The helicopter's tiny size
and the rough seas

make it hard to find.

On the damaged helicopter,

commander Roberts
briefs the passengers.

Roberts: Gentlemen,
you are obviously aware

of the severe vibration.

We've had a lightning strike.

So, please, pull up your hoods,
zip up your suits,

and prepare
for a possible ditching.

Narrator:
Countless hours of training

are supposed to prepare everyone
on board for a moment like this.

In a real emergency,
how many will remember it?

Roberts: 1,200 feet.
We're still flying.

Let's try to make it
to Brae Alpha and land there.

Narrator: Their destination,
the Brae Alpha platform,

is now only 6.5 miles away.

Three minutes have passed
since the explosion,

and things don't seem
to be getting any worse.

Sole: I'll just try
a few small inputs

to make sure
everything's working.

Yes, we've got control in pitch.

We've got control in roll.

And we've got control in yaw.

Tail rotor!

Narrator: The helicopter
is beginning to spin--

a sure sign that something's
happened to the tail rotor.

The only thing the pilots can do
to stop the spinning

is to switch off
the main rotor blade.

Sole: Power off.

Roberts: Engines off.

Narrator:
Ditching has become inevitable.

56 Charlie is falling fast--

more than 1,900 feet a minute.

With the main rotor
acting like a kind of parachute,

the blades are turned

only by the air
that rushes through them.

Roberts: Mayday! Mayday!

Tail rotor failure.

Ditching.

Brace for emergency landing.

Narrator: At this speed,

they're about 40 seconds
from hitting the North Sea.

The other pilots in 56 Bravo
are searching in vain.

There's no sign
of 56 Charlie--

in the sky or in the water.

Then, they hear
another distress call.

Roberts: Mayday! Mayday!

Tail rotor failure.
Ditching!

Backhouse: Mayday,
mayday, mayday.

Relaying for 56 Charlie.

We have a suspected
tail rotor failure.

He is ditching.

Narrator: Commander Backhouse
in 56 Bravo

knows that he is closest
to the stricken helicopter.

Everything depends on him.

But he's not equipped to locate
the distress beacon

56 Charlie carries.

All he can do is search
mile after mile of gray sea.

On board the rescue ship
Grampian freedom,

the crew begins searching
the sea as well as the sky.

But they know
helicopter 56 Bravo

can cover a bigger area
much faster

than the slow-moving ship.

They do what they can
and wait for better directions.

Sole: Floats, floats!
I can't find the floats!

Roberts:
I got it! I got it!

Just keep at a trim angle!

Sole: Right.

Narrator:
The pilots of 56 Charlie

are about to attempt one of
the most difficult maneuvers:

Ditching,

or landing in the middle
of a heaving sea.

Floats under the helicopter are
meant to keep it from sinking.

If they're deployed too soon
before touchdown,

the chopper may lose
what little stability it has

and topple over.

Too late, and they won't
inflate completely.

Instead of riding the waves,

the helicopter
will sink beneath them.

There's no second chance.

They time it perfectly.

Sole: We're down.

Roberts:
Seems quite stable.

Narrator:
They've landed safely,

but no one knows
if they will stay afloat.

Helicopters are top-heavy.

They feel it could keel over
and sink at any moment.

Man:
Let's get out of here!

Man: Do the doors!

Narrator: They need
to get the life rafts out,

inflate them,
and board them quickly.

They fear that
if the helicopter rolls over,

it will trap them all inside.

Man: Lift that end.

Man: Hold the rope!

Roberts: You go back
and help with the evacuation.

I'm gonna shut things down here.

I'm going to try
one last mayday call.

Narrator: But the evacuation
doesn't go smoothly.

When they throw out
one of the life rafts,

the strong wind blows it back
against the helicopter.

They can't get into it.

Man: We can't get this one down!
Can we go out the other side?

Sole: It's better
we all stay together anyway.

Off you go!
Go on! Go on! Go! Go!

Roberts: Mayday! Mayday!
56 Charlie.

We are on the water, floating,
manning the dinghies.

Narrator: He doesn't
mention their position.

Sole: Make room!
Make room, I said! Make room!

Narrator: The raft
is dangerously overloaded.

There are 18 on board,
and it's only meant for 14.

Water is already
up to their ankles, and rising.

Once in the raft,

they have no way of
communicating where they are.

For the first time,

the pilots are able to see
what caused the disaster.

The rear rotor blade assembly
and gear box have broken off

and are hanging down
the side of the helicopter,

held on
by just a couple of pipes.

No one realizes it yet,
but in the rush,

they've forgotten to bring
the distress beacon with them

from the helicopter.

It sends out a signal that
can be picked up by rescuers.

Forgetting it

could mean the difference
between life and death.

Two ropes attach the life raft
to the helicopter.

They're meant to stop the raft
from drifting away,

but they'll also drag them down
if the helicopter sinks.

One of the passengers
has a knife.

Man: Shall I cut the line?
Roberts: No, not yet.

We have a better chance
of being spotted

if we're close
to the helicopter.

Narrator: Problems mount.

The passengers are trying
to raise the canopy

to protect them,

but it gets stuck.

Without the canopy,

they're at the mercy
of the waves.

And then, the helicopter itself
becomes a danger.

When the doors were jettisoned,

they were supposed
to be designed

to slip down into the water
and sink.

Instead, one of them,
which has a jagged edge,

is floating on the surface

and is heading
straight for the raft.

The life raft has been punctured
by the floating door.

Man: Come on, bail!
Bail with everything you got!

We're going to sink.

Roberts:
No, don't worry about it.

We're not going to sink!

Sole: We've got double-layer
rubber tubes here

filled with air.

It cannot sink!

Man: One wave and we're under!

Narrator: The pilots do their
best to put on a brave face.

Sole: There are other
helicopters and ships out there!

They know we're down!

They heard our mayday!

Narrator:
The overloaded life raft

is getting lower and lower
in the water.

Inside, it's already waist-deep.

Now the pounding waves
are pushing them beneath

the sharp edges of
the drooping helicopter blades.

Sole:
We need to get some distance!

We'll have to cut the line!

Narrator: There are supposed
to be two safety lines

connecting the life raft
to the helicopter--

one short, one long.

But the long line is broken.

Sole:
The long line's been cut!

It's been shredded!

Roberts: You'll have
to cut the short one!

Narrator: The short line

is the only thing attaching them
to the helicopter.

If they cut that,
they'll quickly drift away--

a tiny raft full of men,
at the mercy of the sea.

But if they don't cut it,

the jagged edges
of the helicopter

could tear their life raft
to shreds

and sink them all.

First officer Lionel Sole
makes the decision

and cuts the rope.

They begin to drift away
into the storm.

The conditions are deadly.

Most of their survival suits
are filling with freezing water.

For a person in the water,
hypothermia can begin

when the temperature
of air and water added together

is below 58 degrees Fahrenheit.

In the North Sea in winter,

the temperature
is far below that.

Normal muscle
and brain functions

are quickly affected.

The core body temperature
will sink,

followed by unconsciousness
and death.

Their chances of rescue
are slim.

No one knows where they are...

Just a tiny dot
on a vast, turbulent sea.

Man: Quiet, quiet!

I hear something!

Man: There's a helicopter!

Narrator:
The men are desperate.

This could be their last chance.

Sole: Quickly!
Pass me those flares!

The flares!
In the pocket behind you!

Man:
Come on! Spark the flare!

Man: Here! Over here!
We're over here!

Narrator:
But it's all in vain.

The helicopter passes by.

The men can't believe it.

Their only hope is gone.

On 56 Bravo,

Brian Backhouse
can only see gray water.

But suddenly,
his co-pilot spots something.

Co-pilot:
Contact right, 2 o'clock.

Backhouse: Ok, roger.
Let's investigate.

Backhouse: Target contact.

Co-pilot: Target confirmed.

56 Charlie.

Stand by for position report.

Narrator:
Like a guardian angel,

56 Bravo hovers directly above
the survivors for over an hour,

directing
rescue boats and aircraft

towards this tiny speck
in the ocean.

Sole: He came in
and hovered fairly close

because he wanted to count

the number of people
on board the life raft.

So for a while
he was right over top of us

and blowing us around a bit.

But as soon as he got
the information he wanted,

he backed off,

and he was just
marking the position

for the rescue craft to find us.

Narrator: First to arrive
is the Grampian freedom.

Almost a mile away
from the raft,

the Grampian freedom
launches its fast rescue boat.

The boat sets off at full speed
to the rescue.

But the rain and the waves make
finding the life raft difficult.

Man: Hey, hey, hey, hey!
There's a boat!

Man: It's coming fast!

Man: No, no, no, no!
Don't sink us!

Man: Relax, boys.
They know what they're doing.

Man: Let's go!
Quickly go!

Narrator: The rescue boat
throws a lifeline

to the stranded men,

and they begin pulling
themselves to safety.

But there's another challenge

their training
hasn't prepared them for.

Rob Buchan: We reached
the standby boat.

And you're looking at the hull,
a huge steel hull.

You said,
"I'm never gonna get up there."

But the crews are well-trained.

They wait for the swells
to go up and down

in the right motions.

Roberts:
And they have a large net

hanging down
the side of the boat,

and they said,
"We're going to come alongside,

we'll be on the top of the wave,

and when we shout 'jump,'
you jump and grab the net.

Don't look back,
'cause we'll be gone."

We came alongside,
high up on the wave,

grabbed the net,
the wave went back down,

they were away
and they pulled off,

and we just climbed
the last few feet over the side,

onto the Grampian freedom.

Narrator: Later that day,

a rescue helicopter
winches up 14 of the survivors

and flies them back to Aberdeen.

Four of the men, however,

never want to travel
in a helicopter again,

so they refuse to leave
the Grampian freedom.

They're in for more misery.

They're buffeted
by an enormous gale

for the rest of their long
journey back to Aberdeen.

Through their skill
and against all odds,

Cedric Roberts and Lionel Sole

have saved the lives
of all on board.

Roberts: I must admit,
at the time I did think

that was it,
we were going to die.

Sole: The whole world had
changed from being really good

to being what I thought
was a complete disaster

at that time.

It was the worst situation
I've ever been in in the air,

and I was very worried
that that was going to be it.

Narrator:
But the day after the crash,

they find their account
of what caused the accident

under question.

Jim Ferguson:
Lightning, notionally at least,

should not affect the very
powerful North Sea helicopter.

Tony Jones:
This is the first time

I can recall a lightning strike

having ended up
with this kind of conclusion.

Narrator: The experts are
skeptical of the pilots' story.

No helicopter is known to have
crashed into the North Sea

because of lightning.

Perhaps there had been
some mechanical failure.

There are even rumors
of pilot error...

Of recklessly
flying into storm clouds.

The evidence
to support their story

was now beneath the waves
with 56 Charlie.

The air accident
investigation branch,

Britain's air crash detectives,

begin searching for the truth.

It may look like a rig,

but the Stadive
is actually a ship,

mostly used
for servicing oil platforms.

A day after the accident,

the Stadive is brought in

to find and raise
the missing helicopter

from the bottom
of the North Sea.

The investigation
gets off to a good start.

Within a day,

the television cameras on board
the Stadive's two submersibles

locate what's left
of 56 Charlie on the seabed.

But raising it
is a different matter.

They carry on working
into the night.

Soon, several pieces of
56 Charlie have been recovered.

But still not the vital clue--

the missing tail rotor.

Ed Trimble was the Aaib's
lead investigator.

Ed Trimble: The big problem

was to recover
the tail rotor assembly.

Without that, the investigation
was literally going nowhere.

We knew that
the tail rotor assembly

had been dangling over
the side of the pylon

as the helicopter ditched,

and therefore detached at
some point between the ditching

and where we had caught up
with the main wreckage.

Narrator:
Keeping the Stadive going

would be costly.

Ed Trimble calls his boss.

Trimble: He was fairly skeptical
of our chances.

He asked what I thought
our chances were

of finding the tail rotor,

and I,
being an eternal optimist,

I said "80%,"

to which he replied,
"I think you'd be very lucky

if you've got a 10% chance

of recovering the tail rotor
assembly in the North Sea."

Narrator:
Ed Trimble stays up all night,

relentlessly monitoring
the underwater cameras.

Trimble: I didn't want
to be in a situation

where we would have missed
any evidence of further wreckage

and, in particular, any parts
of the tail rotor assembly.

Man: Go get yourself
a coffee, Eddie.

Trimble: By the time 8:00
was looming,

I decided to go down
to the galley to get a coffee.

And I couldn't have been away

any more than
maximum seven to ten minutes

when I suddenly heard

these tremendously
excited shouts from our team.

Man:
Yes! Eureka! We found it!

Trimble:
As I walked in, I ran in,

there, smack in the middle
of the screen,

was the whole
of the tail rotor assembly.

And even at the first glance,

I could see that
one of the tail rotor blades

showed clear evidence
of a lightning strike.

Narrator: The crew was right.

The submarine's cameras reveal
telltale burn marks

on the tail rotor blade.

A close look at the wreckage
on the deck

reveals that two
of the main rotor blades

were also struck by lightning.

But it's this tail rotor
that suffered the most damage.

Since lightning is not known

to have forced a helicopter to
crash into the North Sea before,

the question is why now?

Ed Trimble called in
lightning expert John Hardwick

to discover just what had hit
56 Charlie.

John Hardwick: What we wanted
to do with this set of tests

was to take a set
of tail rotor blades

from the Super Puma helicopter

and subject them
to varying energy levels

of simulated lightning strikes.

Trimble: The lightning
objectives at Culham

basically were
to try and reproduce

the degree of lightning damage

in order to identify
what kind of level of energy

was associated
with this particular strike.

Narrator:
This home video of the tests

was made by ed Trimble.

Representatives of the company
that makes the Super Puma

were there, too.

Hardwick ran the blade through
several lightning strikes

until he was able
to reproduce the damage

found on the rotor blade.

To do it, he had to generate
a simulated strike

of enormous power--

something far more dangerous

than anyone
thought the helicopter

would be exposed to...

Something that wasn't supposed
to happen over the North Sea.

Sole: There've been
a few incidents over the years--

minor strikes, a little bit
of damage to the helicopter.

But we never expected
anything as severe

as happened on that day.

Narrator:
For one brief instant,

it was more than
all the electrical power

being consumed
in the entire United States--

some 30 billion watts.

And this enormous
flash of lightning

had happened
over the North Sea,

where each year

almost 3 million passengers
fly to the oil platforms.

Sole: The helicopters we fly

are certified
to the highest standards.

It's the same as you'd get
on a major airliner

flying transatlantic.

So we had no reason to believe

that any lightning
that we'd encounter

would do any severe damage
to the helicopter.

Narrator:
Ordinary lightning wouldn't.

But this wasn't ordinary.

Miller: A lightning strike

generates
a huge pulse of energy.

We can detect
these pulses of energy

via multiple
transmitters and receivers

that are situated
throughout Europe.

The information
is calibrated locally,

and once the position
has been triangulated,

that's passed
to the met office in London.

Narrator:
When the records were examined,

they showed something
very peculiar.

This is what
they think happened.

Inside cumulonimbus clouds,

tiny ice crystals

are swept upwards
by the wind currents.

At the top of the cloud,
where it's much colder,

they combine with other crystals
to form hail.

The hail, being heavy,
plummets back to earth.

On the way down,

it hits
the rising water crystals,

causing friction.

The crystals become
electrically charged.

Roberts: On that particular day

there was very little
in the way of indication

that there was any significance
in these clouds.

Sole: We were flying along,

everything just seemed
very normal.

We went through,

what seemed to us by comparison
to what was around that day,

a fairly small cloud.

But there was suddenly a lot of
snow and ice pellets in the air.

Roberts: I've never seen as much
in the way of soft hail pellets

in my whole flying career.

And the worrying thing was

that immediately we knew
that obviously there was a lot,

a high level
of energy in that cloud

to produce
that amount of soft hail,

which also meant

there was a high chance
of there being lightning there.

But by that time,
it was too late.

Narrator: When a helicopter
enters the cloud,

the sharp tips
of its whirling rotor blades

cut through these crystals,

causing more friction,
more electricity,

until it's all released
in a blinding flash.

The records show that
the flash which hit 56 Charlie

had been the only one over the
whole of the North Sea that day,

caused almost certainly
by the helicopter itself.

However, for some reason,

nearly all the damage had been
confined to the tail rotor.

What was it about the tail rotor

that had made it
especially vulnerable?

Then, ed Trimble
made a remarkable discovery.

When the civil
aviation authorities

certified
the Super Puma as safe,

they had missed
something important--

something which may have caused
56 Charlie

to fall from the sky.

Safety investigators
examine the wreckage

of a helicopter which
crash landed in the North Sea.

As they study the ruined
aircraft more closely,

they uncover
the cause of the accident.

When the British
civil aviation authority

laid down
the lightning safety standards,

they were looking
at fiberglass blades--

then the normal material
for helicopter rotors.

But in the 1980s,

plane makers began using
composite materials,

like carbon fiber,

which were lighter and stronger.

In particular,

they began making
the rotor blades

out of carbon fiber
instead of fiberglass.

It was assumed that the same
standards would apply equally

to the new blades.

In the industry,
that's known as "read across,"

and it's very dangerous.

In fact, it was the very design
of these composite blades

which brought down
56 Charlie.

Although made of carbon fiber,

composite blades have
a metal anti-erosion strip

glued on to protect the edge.

That's where
the trouble starts.

Hardwick: Carbon is
a conductor of electricity,

but it's a thousand times
worse than aluminium,

so you get a thousand times
as much heat produced.

Narrator: The carbon blade
gets very, very hot.

And when the current
meets the metal strip

running along the edge...

There is furious
arcing and sparking

until finally part of
the erosion strip explodes.

As little as 3.5 ounces
of the erosion strip flew off.

But it was enough.

Without its weight,
the rear rotor was unbalanced.

That's what caused the vibration
felt on board 56 Charlie

immediately after
the lightning strike.

Three minutes later,

when Lionel Sole
tested out the controls,

the unbalanced blades

put the tail rotor
under enormous stress.

The bolts holding it on snapped.

Sole: We've lost the tail rotor!

Roberts: Tail rotor's gone!

Sole: It was like a blowout
in a car, only much, much worse.

Things at that point
were really very, very worrying.

We both knew what had happened.

We'd lost the tail rotor.

And if you don't do exactly
the right thing at that point,

your life expectancy
is very short.

It's seconds.

We had to do the right thing.

We managed
to point it into wind,

and there was quite a big sea
building up.

And at a hundred feet,
I pulled back on the stick

to flare the helicopter,

slow down its rate of descent.

And we were very fortunate
at that point.

A nice friendly wave came along,

and as I leveled the helicopter,

the wave came up,
we sat on the top of it,

and we went down.

And it was one of the best
landings I've ever done.

But that was luck
more than judgment.

Narrator: As bad as it was,
it could have been worse.

The two hydraulic pipes

connecting the assembly
to the helicopter did not break.

Trimble:
These two small-diameter pipes

had held the mass of the gearbox
and tail rotor assembly,

dangling over
the right side of the pylon.

Narrator: Without the weight
of the rotor assembly,

the helicopter
would have tipped forward.

Trimble: Had that tail rotor
gearbox and tail rotor assembly

completely separated
from the helicopter,

then all 18 lives
would have been lost

because the helicopter would
have pitched down irrecoverably

and gone into the North Sea.

Narrator: The investigators
found the answer

to the mystery
of a helicopter crash.

But they stumbled across
a bigger problem--

one that affects
every air traveler.

Investigators believe
that 56 Charlie's violent end

was caused
by a savage lightning strike

greater than anything
it was built to withstand.

And when the lightning hit,

it exposed a problem
in the carbon fiber blades

that made them vulnerable.

The tremendous heat created

where the carbon fiber
met the metal erosion strip

could occur again.

And the same type
of violent reaction

could hypothetically take place
in any aircraft

that has carbon fiber
mixed with other materials.

Increasingly, aluminum is being
replaced with carbon fiber.

The A380 Airbus, for instance,
has over 20%.

What would happen

if these planes encounter
a monster lightning strike?

This was the investigators'
biggest concern

arising from
the Super Puma accident.

The findings were unexpected

and treated
with some skepticism.

Though the tests indicated that
an unexpected lightning strike

hit 56 Charlie,

Britain's
civil aviation authority

refused to accept it.

No action was taken to increase
the safety standards

that these helicopters
must meet.

Trimble: I thought
that the reaction was poor.

There seemed to be a real
reluctance on their behalf

to accept the evidence.

Narrator: If Britain's air crash
detectives are right,

there is a real concern
facing air travelers.

Flashes of lightning

far greater than aircraft
are supposed to encounter

are possible,

and aircraft made of
newer composite materials

are at increased risk.

For the Super Puma, though,
the lessons have been learned.

The design of the rotor blades
has been improved.

The erosion strips are now
secured with heavy bolts,

and the pilots
have been instructed

to give storm clouds
a wider berth.

The men who must fly
these machines to work

are prepared
to accept the risks.

Buchan:
Now when I fly in a chopper,

especially in the wintertime,

if it's going to be
buffed about with wind,

I sometimes get
in the back of my mind,

this can't happen to me again.

But we've all a choice.

We've all a choice either
to stop or we carry on,

and I'm still here
25 years later,

still earning a living.

Narrator:
The crash of 56 Charlie

was a hair-raising incident

that could have easily
ended in tragedy.

In the winter of 1995,

the skill of captain Ced Roberts
and first officer Lionel Sole

saved the lives
of their 16 passengers.

Roberts and Sole
receive an award for their work.

The guild of air pilots
and air navigators

recognized
their skill and bravery

in the emergency landing.

Roberts: Although we received
a number of awards

after the incident
from various organizations,

one thing I received

which is far more precious to me
than any of them

was from the daughters
of one of my passengers.

It was this little card.
It says, "Dear captain Roberts,

I can't tell you how much
I need to thank you

after you saved my dad's life.

It took a lot of effort
to try to keep calm

while you were falling.

If you hadn't have got
that helicopter in control,

my dad maybe wouldn't
be here today.

Thank you very, very,
very much."