Air Emergency (2003–…): Season 3, Episode 7 - Helicopter Down - full transcript
A helicopter full of oil-rig workers is struck by lightning and goes down in the violent weather of the cold North Sea. How big of a role did the weather play that day?
drives men to some of the most
unpleasant places on earth.
.*
1,000 metres above the frigid
North Sea, disaster strikes.
(FLASH OF LIGHTNING)
Mayday, Mayday. Five Six Charlie.
A helicopter is crippled
in the middle of a sudden storm.
The pilots struggle for control as
it sinks helplessly towards the sea.
They're far from land,
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
shocks those involved,
and reveals a hidden danger that
reaches far beyond the North Sea.
The need for oil
drives men to some of the most
unpleasant places on earth.
This is one of them.
The North Sea divides Britain
from mainland Europe.
It's a shallow sea,
and the cruel winds that race across
it can whip up enormous waves.
The sea is cold, grey and violent.
But there's oil out here,
and so dozens of drilling platforms,
and thousands of men,
must face whatever
the weather throws at them.
The only efficient way to get the men
out there is by helicopter.
The flights are rough and long -
up to 500km each way.
After years,
the trip has become largely routine,
the danger below forgotten by many.
What was that?
(BEEPING)
But on a cold January morning
in 1995,
18 men flying over the North Sea
were faced with a horrible question.
Mayday! Mayday! Mayday!
Tail rotor failure! Ditching.
Could they survive in this
extremely hostile environment?
January 19th, 1995.
Commander Ced Roberts
and First Officer Lionel Sole
work for Bristow Helicopters
in Aberdeen, Scotland.
I'll sign this tech log.
See you upstairs.
OK, I'll have a look
at the weather.
Their job is to ferry oil workers to
the oil platforms in the North Sea.
By mid-morning,
they've completed one trip already,
and are getting ready
to head back out.
Their helicopter
is Super Puma Five Six Charlie.
While it's being checked out
and refuelled,
Flight Officer Sole
checks the flight logs
and Commander Roberts
goes through the weather reports,
updated every two hours.
Weather's OK. Good for January.
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 boom town,
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 one of the workhorses
of the North Sea oil industry.
Used around the world
by industry and military,
they're 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're 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.
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, even great food,
are all provided by management
to ensure the men are entertained.
But there are strict rules too.
To protect the safety of everyone
onboard, there's no drinking,
and smoking is severely restricted.
The potential for disaster
is never 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 is 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 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 seen it all 1,000 times.
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,
and push the window out.
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.
Their bright colours are also
designed to make rescue easier.
The trip to the Brae Alpha
oil platform is 230km.
If all goes well, it will take
little more than an hour.
The first part of their journey
takes them northeast,
along what's called the HMR,
the Helicopter Main Route.
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 40km from The Gate.
For part of the journey,
the radar operators
at Air Traffic Control in Aberdeen
won't be able to see them.
The reason why we lose low-level
radar coverage 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.
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.
If an aircraft flies into that gap,
then it'll disappear from radar.
In the case of Aberdeen, a
helicopter operating about 2,000ft
will disappear into that gap
at about 80 miles.
It's a black hole, which Super Puma
Five Six Charlie is now entering.
The helicopter and 18 men on board
are over halfway to the rigs.
And from this moment on,
no-one knows exactly where they are.
Five Six Charlie
is a Super Puma helicopter
serving the North Sea oil platforms
off the coast of Britain.
It's halfway through a long flight
carrying 16 passengers
to the Brae Alpha oil rig.
The crew is getting concerned about
what they see on their weather radar.
The forecast
called for scattered clouds,
but the weather is changing fast.
What do you think about this cloud?
It's quite thin. Yeah, but look.
We're getting some cumulus too.
It's quite small.
About 100 yards across?
Yeah, but it's developing a bit.
Mmm.
Cumulus are puffy white clouds,
like balls of cotton wool.
They're beautiful to look at,
and usually harmless.
They only last between
five and 40 minutes.
But helicopter pilots prefer
to go above them if possible,
because the air inside and below
gets very bumpy.
Let's try to climb above it.
Go to 5,000ft.
Right.
Oh, look. There's a line of 'em,
all along the route
to exactly where we're going.
Yeah,
we're not gaining anything by this.
Let's drop back down to 3,000ft.
Right.
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 vapour condenses
into clouds, cools, then sinks.
It creates strong winds,
pushing the huge masses around.
The friction caused by this motion
can make the clouds
electrically charged,
and that electricity
can be released as lightning.
What starts out as a placid day
can end up in a violent storm.
It's now one hour after take-off,
and Five Six Charlie
is approaching The Gate,
the point where helicopters
begin their descent
to the individual oil platforms.
They're 25 miles
from their destination,
and the weather
is starting to get worse.
Brae Traffic, Five Six Charlie,
120 miles on the zero 56 HMR.
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.
Roger, Five Six Charlie.
I have your flight watch.
Aberdeen information. Bristow's
Five Six Charlie at 120 miles.
Leaving 3,000 feet.
Brae has the flight watch.
Roger, Five Six Charlie.
Continue with Brae Traffic.
Quite 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.
Cumulonimbus,
that's the granddaddy of all clouds.
It stretches from about
1,000ft at its base
all the way up to 28, 30,000ft.
They are the most dangerous clouds
aircraft can come across
particularly small aircraft
like helicopters.
Within a cumulonimbus, you're
going to find severe turbulence,
you're going to find ice and heavy
rain, and, of course, lightning.
If you're flying a helicopter,
that's not where you want to be.
As they begin their descent,
the Super Puma enters the line of
clouds that stands in their path.
Bits of cloud coming up here.
It's OK. It's still green.
Just carry on through that.
Green on the weather radar
means there's rain,
but it's not heavy enough
to worry about.
What the pilot sees is simply
like a television screen
and on that television screen
he has a map,
and overlaid on that map
is a series of banded colours.
If there's no rain,
he has a blank map.
If there's lots of rain
and it's heavy,
he has lots of red squares on that,
and that gives you an idea of the
intensity and location of rainfall.
Onboard Five Six Charlie,
the weather gets more intense.
They begin to get pelted by hail.
Hey! Where did this come from?
It's coming in through the vent.
It's like being inside a bean bag,
swamped by polystyrene balls!
It's so thick.
How come the engine's
are still running?
There can't be any air
left out there! (LAUGHS)
Now another problem.
(BEEPING)
We've got a hardover
on the Ice Detector.
It's probably just some ice pellets
stuck in the probe.
Right.
The helicopter has an ice detector,
a probe outside the craft,
which is supposed to tell the pilots
whether there's ice on the blades.
But they think
it's become jammed with ice
and is giving a false reading.
And then...
(LOUD CRASH)
Disaster.
Bloody hell!
What was that?
Lightning. I saw it.
This is bad. There's something
very wrong with this.
We'll have to go down, I'm afraid.
The helicopter has been 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.
Mayday! Mayday! Five Six Charlie.
Lightning strike. Severe vibration.
Mayday! Mayday!
40km away,
another helicopter is about
to leave an oil platform.
Commander Brian Backhouse
is loading passengers onto 56 Bravo
and preparing to fly
back to Aberdeen.
That's everyone, all set.
Suddenly, the loading officer
hears Lionel Sole's Mayday call
on his radio.
Mayday! Mayday! Five Six Charlie.
Lightning strike.
Hear that Mayday? Fifty Six Charlie!
Gentlemen, my apologies,
but we have to disembark you.
We have an airborne emergency
on a sister aircraft.
Backhouse hurriedly unloads
his passengers.
He intends to help if he can.
Meanwhile, a gale is steadily
building up,
with winds in excess of 70kmh.
The seas are mounting.
The crew of Five Six Charlie
are struggling
to keep control of their
crippled helicopter.
After the initial flash, though,
the situation hasn't got worse.
While closer to the sea,
they continue to limp
towards the platform.
The Grampian Freedom is a standby
ship positioned near the oil rigs,
to give oil workers a way to escape
if anything goes wrong.
Her skipper, John MacInnes, hears
the helicopter's distress call.
We increased, er, speed
to full speed ahead.
Er, everybody was informed
aboard the vessel
and told to get ready, er,
for survivors to be taken aboard.
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.
Let's go to The Gate
and proceed from there.
At least they have a starting point.
The Grampian Freedom doesn't know
where to go either.
They're getting conflicting messages
about where Five Six 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.
Gentlemen, you're 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.
Countless hours of training
is supposed to prepare all onboard
for a moment like this.
In a real emergency,
how many will remember it?
One thousand two hundred feet.
We're still flying.
Their destination,
the Brae Alpha platform,
is now only 11 kilometres away.
Three minutes have passed
since the explosion.
And things don't seem
to be getting any worse.
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.
(LOUD CRASH)
Tail rotor!
The helicopter
is beginning to spin round.
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.
Power off.
Engines off.
Ditching has become inevitable.
(LOUD BREATHING)
Five Six Charlie is falling fast,
more than 600 metres a minute,
with the main rotor acting
like a kind of parachute,
the blades being turned only by
the air that rushes through them.
Mayday! Mayday!
Tail-rotor failure. Ditching!
Brace for emergency landing.
At this speed, they're about 40
seconds from hitting the North Sea.
The other pilots in Five Six Bravo
are searching in vain.
There's no sign of Five Six Charlie
in the sky, or in the water.
Then they hear
another distress call.
Mayday! Mayday! Tail rotor failure.
Ditching!
Mayday! Mayday! Mayday!
Relaying for Five Six Charlie.
Suspected tail rotor failure.
He is ditching.
Commander Backhouse
in Five Six Bravo knows
that he is closest
to the stricken helicopter.
Everything depends on him.
But he is not equipped to locate
the distress beacon Five Six Charlie
will use when it ditches.
All he can do is search
mile after mile of grey sea.
Back on the Grampian Freedom,
the crew begins searching the sea,
as well as the sky.
But they know Five Six Bravo
can cover ground more quickly
than the enormous, slow-moving ship.
They do what they can -
and wait for better directions.
Floats! Floats!
I can't find the floats!
I got it! I got it!
Just keep it at trim angle!
The pilots of Five Six Charlie
are about to attempt
one of the most difficult manoeuvres.
Ditching, or landing in the middle
of the heaving sea.
Floats under the helicopter
are meant 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 below them.
There is no second chance.
They time it perfectly.
We're down!
Seems quite stable.
They've landed safely -
but no-one knows
if they will stay afloat.
Helicopters are top heavy -
and they fear it could keel over
and sink at any moment.
Let's get out of here.
Do the doors!
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.
Lift that end.
Hold the rope.
You go back and help the evacuation.
I'll shut down here.
I'm going to try
one last Mayday call.
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.
We can't get this one down!
Can we go out the other side?
Better we all stay together anyway.
Off you go! Go on, GO!
GO!
SOLE: Mayday, Mayday.
Five Six Charlie.
We are on the water. Floating.
Manning the dinghies!
He doesn't mention their position.
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.
They have crashed tantalisingly close
to their destination.
But 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 realises 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.
Shall I cut the line?
No, not yet.
We have a better chance
of being spotted
if we're close
to the helicopter.
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 it's heading
straight for the raft.
(HISSING)
The life raft has been punctured
by the floating door.
Come on, bail, bail,
with everything you got!
We're gonna sink.
No, don't worry about it,
we're not going to sink!
One wave and we're under!
The pilots do their best
to put on a brave face.
There are other helicopters
and ships out there.
They know we're down.
They heard our Mayday!
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.
We need to get some distance.
We'll have to cut the line.
The two safety lines are still tying
the life raft to the helicopter,
one short, one long.
They will cut the short one
so they can float further away
from the menace of the rotor blades.
The long line's been cut!
It's been shredded!
You'll have to cut the short one!
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.
18 people have
scrambled aboard a life raft
after their helicopter
crashed into the North Sea.
The raft is overloaded.
It's been punctured by the jagged
metal edges of the helicopter door,
and is getting
lower and lower in the water.
They have to get away
from the helicopter.
Flight Officer Lionel Sole
takes the fateful decision
and cuts the rope.
They begin to drift away
into the storm.
The conditions are deadly.
Most of their survival suits
are leaking freezing water.
For a person in the water,
hypothermia can begin
when the temperatures
of air and water added together
is below 50 degrees Centigrade.
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.
Quiet, quiet! I hear something!
There's a helicopter!
(SHOUTING)
The men are desperate.
This could be their last chance.
Quickly!
Pass me those flares,
the flares in the pocket behind you!
Here! Over here! Here it is!
We're over here!
But it's all in vain.
The helicopter passes by.
The men can't believe it.
Their only hope is gone.
On Five Six Bravo, Brian Backhouse
can see only grey seas.
But suddenly his co-pilot
spots something.
Contact, right, two o'clock.
OK. Roger. Let's investigate.
(SHOUTING)
Target, contact.
Target confirmed. Fifty Six Charlie.
Standby for position report.
Like a guardian angel, Five Six Bravo
hovers directly above the survivors
for over an hour,
directing rescue boats and aircraft
towards this tiny speck in the ocean.
First to arrive
is the Grampian Freedom.
We had lookouts
all around the vessel.
Some on top of the bridge
and on each wing.
A helicopter came and he started
criss-crossing our bow,
which is normal procedure
in that kind of situation.
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.
The rain and waves
make finding the raft difficult.
No, no, no, no! Don't sink us!
Relax, boys,
they know what they're doing.
Let's go! Quickly! Go!
The rescue boat throws
a lifeline to the stranded men.
They begin pulling themselves
to safety.
14 survivors are taken back
to the Grampian Freedom.
Four to another ship.
The men are freezing cold
and in a state of shock,
but otherwise unharmed.
Through their skill,
and against all the odds,
Cedric Roberts and Lionel Sole
have saved the lives of all on-board.
I must admit at the time,
I did think, that was it,
we were gonna die.
The whole world changed from
being really good
to being what I thought
was a complete disaster at the 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.
The crew had survived the ditching,
and kept the passengers safe
until their rescue.
But the day after the accident,
they came under suspicion.
Their report on what happened
starts being questioned.
Lightning, notionally at least,
should not affect a very powerful
North Sea helicopter.
This is the first time
I can recall a lightning strike
having ended up with
this kind of conclusion.
The experts are sceptical
of the pilots' story.
No other helicopter is known to have
crashed into the North Sea
because of lightning.
Perhaps there had been some
mechanical failure.
There are even whispers
of pilot error -
of recklessly flying into
storm clouds.
The evidence to support their story
was now beneath the waves
with Five Six 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.
It has nine powerful engines,
which keep it stable
in almost any weather.
And it carries miniature submarines
for underwater exploration.
A day after the accident,
it's 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
Five Six Charlie on the seabed.
But raising it is a different matter.
They carry on working into the night.
Soon, several pieces of Five Six
Charlie have been recovered.
But still not the vital clue -
the missing tail rotor.
Ed Trimble
was the AAIB's lead investigator.
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, had detached
at some point between the ditching
and where we had caught up
with the main wreckage.
Keeping the Stadive going
would cost another £20,000 a day.
Ed Trimble rang his boss.
He was fairly sceptical
of our chances.
Uh, he asked what I thought
our chances were of finding
the, uh, 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."
Ed Trimble stays up all night,
relentlessly monitoring
the underwater cameras.
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.
By the time eight o'clock
was looming
I decided to go down to the galley
to get a coffee.
I couldn't have been away any more
than seven to ten minutes,
when I suddenly heard
these tremendously
excited shouts from our team.
Yes! Eureka! We've found it.
As I walked in, I ran in, there,
smack in the middle of the screen,
was the whole of the
tail-rotor assembly.
Even at the first glance,
I could see that
one of the tail-rotor blades
showed clear evidence
of a lightning strike.
The crew was right.
The submarine's cameras
revealed tell-tale burn marks
on the tail rotor blade.
A close look at the wreckage
on the deck
reveals 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 Five Six Charlie.
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.
The lightning objectives
were to try and reproduce
the degree of lightning damage,
in order to identify
what level of energy
was associated with this
particular strike.
This home video of the tests
was taken by Ed Trimble.
Representatives of the company that
makes the Super Puma were there too.
(SMALL EXPLOSIONS)
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.
There had been a few incidents
over the years, minor strikes,
little bit of damage
to the helicopter.
But we never expected anything as
severe as happened on that day.
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
three million passengers
fly unsuspecting
to the oil platforms.
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 encountered
would do any severe damage
to the helicopter.
Ordinary lightning wouldn't.
But this wasn't ordinary.
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.
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.
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.
(LOUD CRASH)
The records showed that the flash
which hit Five Six Charlie
had been the only one recorded
over 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 Five
Six Charlie to fall from the sky.
When the British Civil Aviation
Authority
laid down the lightning
safety standards,
they were looking
at fibreglass blades,
then the normal material
for helicopter rotors.
But in the 1980s, plane-makers began
using the new composite materials,
like carbon fibre,
which were lighter and stronger.
In particular, they began making
the rotor blades out of carbon fibre
instead of fibreglass.
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 Five Six Charlie.
Although made of carbon fibre,
composite blades have a metal
anti-erosion strip glued on
to protect the edge.
That's where the trouble starts.
Carbon is a conductor of electricity
but it's 1,000 times worse
than aluminium
so you get 1,000 times
as much heat produced.
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 100g
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 Five Six 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.
(LOUD METALLIC CRASH)
We've lost the tail rotor!
Tail rotor's gone!
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,
and at 100ft, I pull 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 levelled the helicopter,
the wave came up,
we sat on the top of it
and we went down.
It was one of the best
landings I've ever done,
but that was luck
more than judgement.
As bad as it was,
it could have been worse.
The two hydraulic pipes connecting
the assembly to the helicopter
did not break.
These two small-diameter pipes
had held the mass of the gear box
and tail-rotor assembly dangling
over the right side of the pylon.
Without the weight
of the rotor assembly,
the helicopter
would have tipped forward.
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.
The investigators found the answer
to the mystery of a helicopter crash.
But they stumbled across
a bigger problem,
one that affects every air traveller.
(LIGHTNING CRACKS)
Investigators believe
that Five Six 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-fibre blades
that made them vulnerable.
The tremendous heat created
where the carbon fibre
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 fibre
mixed with other materials.
Increasingly, aluminium is being
replaced with carbon fibre.
The world's largest plane,
the A380 Airbus, for instance,
has over 20%.
Its rival from Boeing,
the Dreamliner,
will contain 50% carbon fibre.
What will happen if these planes
encounter a monster lightning strike?
This was the investigators'
biggest concern
arising out of this
Super Puma accident.
The findings were unexpected,
and treated with some scepticism.
Though the tests indicated
that an unexpectedly large lightning
strike hit Five Six Charlie,
Britain's Civil Aviation Authority
refused to accept it.
The tests were not proof.
There was no way to know for sure
how powerful the lightning was
that hit the helicopter.
No action was taken to increase
the safety standards
that these
helicopters must meet.
I thought that the reaction
was poor.
There seemed to be, er,
a real reluctance, on their behalf,
to accept the evidence.
If Britain's air crash detectives
are right,
there is a real concern
facing air travellers.
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 vastly strengthened.
The erosion strips are now secured
with heavy bolts.
And 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.
Well, I think the morning that we
ditched, we were very fortunate,
because the outcome
could have gone horribly wrong.
But we survived. We got home.
My feelings that morning were,
this could never happen to me.
Now, when I fly in a chopper,
especially in winter time,
if it's going to be buffeted about
in the wind
I sometimes get the back of my mind,
this can happen to me again.
But we've all a choice.
We've all a choice to stop
or we carry on
and I'm still there 25 years later,
still earning a living.
The crash of Five Six Charlie
was a hair-raising incident
that could so easily
have ended in tragedy.
In the winter of 1995,
the skill of Commander Ced Roberts
and Flight 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 recognised their skill
and bravery in the emergency landing.
Although we received a number
of awards after the incident
from various organisations,
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 and 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."
unpleasant places on earth.
.*
1,000 metres above the frigid
North Sea, disaster strikes.
(FLASH OF LIGHTNING)
Mayday, Mayday. Five Six Charlie.
A helicopter is crippled
in the middle of a sudden storm.
The pilots struggle for control as
it sinks helplessly towards the sea.
They're far from land,
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
shocks those involved,
and reveals a hidden danger that
reaches far beyond the North Sea.
The need for oil
drives men to some of the most
unpleasant places on earth.
This is one of them.
The North Sea divides Britain
from mainland Europe.
It's a shallow sea,
and the cruel winds that race across
it can whip up enormous waves.
The sea is cold, grey and violent.
But there's oil out here,
and so dozens of drilling platforms,
and thousands of men,
must face whatever
the weather throws at them.
The only efficient way to get the men
out there is by helicopter.
The flights are rough and long -
up to 500km each way.
After years,
the trip has become largely routine,
the danger below forgotten by many.
What was that?
(BEEPING)
But on a cold January morning
in 1995,
18 men flying over the North Sea
were faced with a horrible question.
Mayday! Mayday! Mayday!
Tail rotor failure! Ditching.
Could they survive in this
extremely hostile environment?
January 19th, 1995.
Commander Ced Roberts
and First Officer Lionel Sole
work for Bristow Helicopters
in Aberdeen, Scotland.
I'll sign this tech log.
See you upstairs.
OK, I'll have a look
at the weather.
Their job is to ferry oil workers to
the oil platforms in the North Sea.
By mid-morning,
they've completed one trip already,
and are getting ready
to head back out.
Their helicopter
is Super Puma Five Six Charlie.
While it's being checked out
and refuelled,
Flight Officer Sole
checks the flight logs
and Commander Roberts
goes through the weather reports,
updated every two hours.
Weather's OK. Good for January.
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 boom town,
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 one of the workhorses
of the North Sea oil industry.
Used around the world
by industry and military,
they're 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're 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.
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, even great food,
are all provided by management
to ensure the men are entertained.
But there are strict rules too.
To protect the safety of everyone
onboard, there's no drinking,
and smoking is severely restricted.
The potential for disaster
is never 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 is 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 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 seen it all 1,000 times.
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,
and push the window out.
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.
Their bright colours are also
designed to make rescue easier.
The trip to the Brae Alpha
oil platform is 230km.
If all goes well, it will take
little more than an hour.
The first part of their journey
takes them northeast,
along what's called the HMR,
the Helicopter Main Route.
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 40km from The Gate.
For part of the journey,
the radar operators
at Air Traffic Control in Aberdeen
won't be able to see them.
The reason why we lose low-level
radar coverage 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.
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.
If an aircraft flies into that gap,
then it'll disappear from radar.
In the case of Aberdeen, a
helicopter operating about 2,000ft
will disappear into that gap
at about 80 miles.
It's a black hole, which Super Puma
Five Six Charlie is now entering.
The helicopter and 18 men on board
are over halfway to the rigs.
And from this moment on,
no-one knows exactly where they are.
Five Six Charlie
is a Super Puma helicopter
serving the North Sea oil platforms
off the coast of Britain.
It's halfway through a long flight
carrying 16 passengers
to the Brae Alpha oil rig.
The crew is getting concerned about
what they see on their weather radar.
The forecast
called for scattered clouds,
but the weather is changing fast.
What do you think about this cloud?
It's quite thin. Yeah, but look.
We're getting some cumulus too.
It's quite small.
About 100 yards across?
Yeah, but it's developing a bit.
Mmm.
Cumulus are puffy white clouds,
like balls of cotton wool.
They're beautiful to look at,
and usually harmless.
They only last between
five and 40 minutes.
But helicopter pilots prefer
to go above them if possible,
because the air inside and below
gets very bumpy.
Let's try to climb above it.
Go to 5,000ft.
Right.
Oh, look. There's a line of 'em,
all along the route
to exactly where we're going.
Yeah,
we're not gaining anything by this.
Let's drop back down to 3,000ft.
Right.
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 vapour condenses
into clouds, cools, then sinks.
It creates strong winds,
pushing the huge masses around.
The friction caused by this motion
can make the clouds
electrically charged,
and that electricity
can be released as lightning.
What starts out as a placid day
can end up in a violent storm.
It's now one hour after take-off,
and Five Six Charlie
is approaching The Gate,
the point where helicopters
begin their descent
to the individual oil platforms.
They're 25 miles
from their destination,
and the weather
is starting to get worse.
Brae Traffic, Five Six Charlie,
120 miles on the zero 56 HMR.
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.
Roger, Five Six Charlie.
I have your flight watch.
Aberdeen information. Bristow's
Five Six Charlie at 120 miles.
Leaving 3,000 feet.
Brae has the flight watch.
Roger, Five Six Charlie.
Continue with Brae Traffic.
Quite 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.
Cumulonimbus,
that's the granddaddy of all clouds.
It stretches from about
1,000ft at its base
all the way up to 28, 30,000ft.
They are the most dangerous clouds
aircraft can come across
particularly small aircraft
like helicopters.
Within a cumulonimbus, you're
going to find severe turbulence,
you're going to find ice and heavy
rain, and, of course, lightning.
If you're flying a helicopter,
that's not where you want to be.
As they begin their descent,
the Super Puma enters the line of
clouds that stands in their path.
Bits of cloud coming up here.
It's OK. It's still green.
Just carry on through that.
Green on the weather radar
means there's rain,
but it's not heavy enough
to worry about.
What the pilot sees is simply
like a television screen
and on that television screen
he has a map,
and overlaid on that map
is a series of banded colours.
If there's no rain,
he has a blank map.
If there's lots of rain
and it's heavy,
he has lots of red squares on that,
and that gives you an idea of the
intensity and location of rainfall.
Onboard Five Six Charlie,
the weather gets more intense.
They begin to get pelted by hail.
Hey! Where did this come from?
It's coming in through the vent.
It's like being inside a bean bag,
swamped by polystyrene balls!
It's so thick.
How come the engine's
are still running?
There can't be any air
left out there! (LAUGHS)
Now another problem.
(BEEPING)
We've got a hardover
on the Ice Detector.
It's probably just some ice pellets
stuck in the probe.
Right.
The helicopter has an ice detector,
a probe outside the craft,
which is supposed to tell the pilots
whether there's ice on the blades.
But they think
it's become jammed with ice
and is giving a false reading.
And then...
(LOUD CRASH)
Disaster.
Bloody hell!
What was that?
Lightning. I saw it.
This is bad. There's something
very wrong with this.
We'll have to go down, I'm afraid.
The helicopter has been 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.
Mayday! Mayday! Five Six Charlie.
Lightning strike. Severe vibration.
Mayday! Mayday!
40km away,
another helicopter is about
to leave an oil platform.
Commander Brian Backhouse
is loading passengers onto 56 Bravo
and preparing to fly
back to Aberdeen.
That's everyone, all set.
Suddenly, the loading officer
hears Lionel Sole's Mayday call
on his radio.
Mayday! Mayday! Five Six Charlie.
Lightning strike.
Hear that Mayday? Fifty Six Charlie!
Gentlemen, my apologies,
but we have to disembark you.
We have an airborne emergency
on a sister aircraft.
Backhouse hurriedly unloads
his passengers.
He intends to help if he can.
Meanwhile, a gale is steadily
building up,
with winds in excess of 70kmh.
The seas are mounting.
The crew of Five Six Charlie
are struggling
to keep control of their
crippled helicopter.
After the initial flash, though,
the situation hasn't got worse.
While closer to the sea,
they continue to limp
towards the platform.
The Grampian Freedom is a standby
ship positioned near the oil rigs,
to give oil workers a way to escape
if anything goes wrong.
Her skipper, John MacInnes, hears
the helicopter's distress call.
We increased, er, speed
to full speed ahead.
Er, everybody was informed
aboard the vessel
and told to get ready, er,
for survivors to be taken aboard.
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.
Let's go to The Gate
and proceed from there.
At least they have a starting point.
The Grampian Freedom doesn't know
where to go either.
They're getting conflicting messages
about where Five Six 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.
Gentlemen, you're 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.
Countless hours of training
is supposed to prepare all onboard
for a moment like this.
In a real emergency,
how many will remember it?
One thousand two hundred feet.
We're still flying.
Their destination,
the Brae Alpha platform,
is now only 11 kilometres away.
Three minutes have passed
since the explosion.
And things don't seem
to be getting any worse.
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.
(LOUD CRASH)
Tail rotor!
The helicopter
is beginning to spin round.
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.
Power off.
Engines off.
Ditching has become inevitable.
(LOUD BREATHING)
Five Six Charlie is falling fast,
more than 600 metres a minute,
with the main rotor acting
like a kind of parachute,
the blades being turned only by
the air that rushes through them.
Mayday! Mayday!
Tail-rotor failure. Ditching!
Brace for emergency landing.
At this speed, they're about 40
seconds from hitting the North Sea.
The other pilots in Five Six Bravo
are searching in vain.
There's no sign of Five Six Charlie
in the sky, or in the water.
Then they hear
another distress call.
Mayday! Mayday! Tail rotor failure.
Ditching!
Mayday! Mayday! Mayday!
Relaying for Five Six Charlie.
Suspected tail rotor failure.
He is ditching.
Commander Backhouse
in Five Six Bravo knows
that he is closest
to the stricken helicopter.
Everything depends on him.
But he is not equipped to locate
the distress beacon Five Six Charlie
will use when it ditches.
All he can do is search
mile after mile of grey sea.
Back on the Grampian Freedom,
the crew begins searching the sea,
as well as the sky.
But they know Five Six Bravo
can cover ground more quickly
than the enormous, slow-moving ship.
They do what they can -
and wait for better directions.
Floats! Floats!
I can't find the floats!
I got it! I got it!
Just keep it at trim angle!
The pilots of Five Six Charlie
are about to attempt
one of the most difficult manoeuvres.
Ditching, or landing in the middle
of the heaving sea.
Floats under the helicopter
are meant 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 below them.
There is no second chance.
They time it perfectly.
We're down!
Seems quite stable.
They've landed safely -
but no-one knows
if they will stay afloat.
Helicopters are top heavy -
and they fear it could keel over
and sink at any moment.
Let's get out of here.
Do the doors!
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.
Lift that end.
Hold the rope.
You go back and help the evacuation.
I'll shut down here.
I'm going to try
one last Mayday call.
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.
We can't get this one down!
Can we go out the other side?
Better we all stay together anyway.
Off you go! Go on, GO!
GO!
SOLE: Mayday, Mayday.
Five Six Charlie.
We are on the water. Floating.
Manning the dinghies!
He doesn't mention their position.
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.
They have crashed tantalisingly close
to their destination.
But 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 realises 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.
Shall I cut the line?
No, not yet.
We have a better chance
of being spotted
if we're close
to the helicopter.
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 it's heading
straight for the raft.
(HISSING)
The life raft has been punctured
by the floating door.
Come on, bail, bail,
with everything you got!
We're gonna sink.
No, don't worry about it,
we're not going to sink!
One wave and we're under!
The pilots do their best
to put on a brave face.
There are other helicopters
and ships out there.
They know we're down.
They heard our Mayday!
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.
We need to get some distance.
We'll have to cut the line.
The two safety lines are still tying
the life raft to the helicopter,
one short, one long.
They will cut the short one
so they can float further away
from the menace of the rotor blades.
The long line's been cut!
It's been shredded!
You'll have to cut the short one!
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.
18 people have
scrambled aboard a life raft
after their helicopter
crashed into the North Sea.
The raft is overloaded.
It's been punctured by the jagged
metal edges of the helicopter door,
and is getting
lower and lower in the water.
They have to get away
from the helicopter.
Flight Officer Lionel Sole
takes the fateful decision
and cuts the rope.
They begin to drift away
into the storm.
The conditions are deadly.
Most of their survival suits
are leaking freezing water.
For a person in the water,
hypothermia can begin
when the temperatures
of air and water added together
is below 50 degrees Centigrade.
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.
Quiet, quiet! I hear something!
There's a helicopter!
(SHOUTING)
The men are desperate.
This could be their last chance.
Quickly!
Pass me those flares,
the flares in the pocket behind you!
Here! Over here! Here it is!
We're over here!
But it's all in vain.
The helicopter passes by.
The men can't believe it.
Their only hope is gone.
On Five Six Bravo, Brian Backhouse
can see only grey seas.
But suddenly his co-pilot
spots something.
Contact, right, two o'clock.
OK. Roger. Let's investigate.
(SHOUTING)
Target, contact.
Target confirmed. Fifty Six Charlie.
Standby for position report.
Like a guardian angel, Five Six Bravo
hovers directly above the survivors
for over an hour,
directing rescue boats and aircraft
towards this tiny speck in the ocean.
First to arrive
is the Grampian Freedom.
We had lookouts
all around the vessel.
Some on top of the bridge
and on each wing.
A helicopter came and he started
criss-crossing our bow,
which is normal procedure
in that kind of situation.
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.
The rain and waves
make finding the raft difficult.
No, no, no, no! Don't sink us!
Relax, boys,
they know what they're doing.
Let's go! Quickly! Go!
The rescue boat throws
a lifeline to the stranded men.
They begin pulling themselves
to safety.
14 survivors are taken back
to the Grampian Freedom.
Four to another ship.
The men are freezing cold
and in a state of shock,
but otherwise unharmed.
Through their skill,
and against all the odds,
Cedric Roberts and Lionel Sole
have saved the lives of all on-board.
I must admit at the time,
I did think, that was it,
we were gonna die.
The whole world changed from
being really good
to being what I thought
was a complete disaster at the 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.
The crew had survived the ditching,
and kept the passengers safe
until their rescue.
But the day after the accident,
they came under suspicion.
Their report on what happened
starts being questioned.
Lightning, notionally at least,
should not affect a very powerful
North Sea helicopter.
This is the first time
I can recall a lightning strike
having ended up with
this kind of conclusion.
The experts are sceptical
of the pilots' story.
No other helicopter is known to have
crashed into the North Sea
because of lightning.
Perhaps there had been some
mechanical failure.
There are even whispers
of pilot error -
of recklessly flying into
storm clouds.
The evidence to support their story
was now beneath the waves
with Five Six 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.
It has nine powerful engines,
which keep it stable
in almost any weather.
And it carries miniature submarines
for underwater exploration.
A day after the accident,
it's 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
Five Six Charlie on the seabed.
But raising it is a different matter.
They carry on working into the night.
Soon, several pieces of Five Six
Charlie have been recovered.
But still not the vital clue -
the missing tail rotor.
Ed Trimble
was the AAIB's lead investigator.
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, had detached
at some point between the ditching
and where we had caught up
with the main wreckage.
Keeping the Stadive going
would cost another £20,000 a day.
Ed Trimble rang his boss.
He was fairly sceptical
of our chances.
Uh, he asked what I thought
our chances were of finding
the, uh, 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."
Ed Trimble stays up all night,
relentlessly monitoring
the underwater cameras.
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.
By the time eight o'clock
was looming
I decided to go down to the galley
to get a coffee.
I couldn't have been away any more
than seven to ten minutes,
when I suddenly heard
these tremendously
excited shouts from our team.
Yes! Eureka! We've found it.
As I walked in, I ran in, there,
smack in the middle of the screen,
was the whole of the
tail-rotor assembly.
Even at the first glance,
I could see that
one of the tail-rotor blades
showed clear evidence
of a lightning strike.
The crew was right.
The submarine's cameras
revealed tell-tale burn marks
on the tail rotor blade.
A close look at the wreckage
on the deck
reveals 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 Five Six Charlie.
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.
The lightning objectives
were to try and reproduce
the degree of lightning damage,
in order to identify
what level of energy
was associated with this
particular strike.
This home video of the tests
was taken by Ed Trimble.
Representatives of the company that
makes the Super Puma were there too.
(SMALL EXPLOSIONS)
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.
There had been a few incidents
over the years, minor strikes,
little bit of damage
to the helicopter.
But we never expected anything as
severe as happened on that day.
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
three million passengers
fly unsuspecting
to the oil platforms.
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 encountered
would do any severe damage
to the helicopter.
Ordinary lightning wouldn't.
But this wasn't ordinary.
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.
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.
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.
(LOUD CRASH)
The records showed that the flash
which hit Five Six Charlie
had been the only one recorded
over 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 Five
Six Charlie to fall from the sky.
When the British Civil Aviation
Authority
laid down the lightning
safety standards,
they were looking
at fibreglass blades,
then the normal material
for helicopter rotors.
But in the 1980s, plane-makers began
using the new composite materials,
like carbon fibre,
which were lighter and stronger.
In particular, they began making
the rotor blades out of carbon fibre
instead of fibreglass.
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 Five Six Charlie.
Although made of carbon fibre,
composite blades have a metal
anti-erosion strip glued on
to protect the edge.
That's where the trouble starts.
Carbon is a conductor of electricity
but it's 1,000 times worse
than aluminium
so you get 1,000 times
as much heat produced.
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 100g
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 Five Six 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.
(LOUD METALLIC CRASH)
We've lost the tail rotor!
Tail rotor's gone!
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,
and at 100ft, I pull 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 levelled the helicopter,
the wave came up,
we sat on the top of it
and we went down.
It was one of the best
landings I've ever done,
but that was luck
more than judgement.
As bad as it was,
it could have been worse.
The two hydraulic pipes connecting
the assembly to the helicopter
did not break.
These two small-diameter pipes
had held the mass of the gear box
and tail-rotor assembly dangling
over the right side of the pylon.
Without the weight
of the rotor assembly,
the helicopter
would have tipped forward.
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.
The investigators found the answer
to the mystery of a helicopter crash.
But they stumbled across
a bigger problem,
one that affects every air traveller.
(LIGHTNING CRACKS)
Investigators believe
that Five Six 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-fibre blades
that made them vulnerable.
The tremendous heat created
where the carbon fibre
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 fibre
mixed with other materials.
Increasingly, aluminium is being
replaced with carbon fibre.
The world's largest plane,
the A380 Airbus, for instance,
has over 20%.
Its rival from Boeing,
the Dreamliner,
will contain 50% carbon fibre.
What will happen if these planes
encounter a monster lightning strike?
This was the investigators'
biggest concern
arising out of this
Super Puma accident.
The findings were unexpected,
and treated with some scepticism.
Though the tests indicated
that an unexpectedly large lightning
strike hit Five Six Charlie,
Britain's Civil Aviation Authority
refused to accept it.
The tests were not proof.
There was no way to know for sure
how powerful the lightning was
that hit the helicopter.
No action was taken to increase
the safety standards
that these
helicopters must meet.
I thought that the reaction
was poor.
There seemed to be, er,
a real reluctance, on their behalf,
to accept the evidence.
If Britain's air crash detectives
are right,
there is a real concern
facing air travellers.
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 vastly strengthened.
The erosion strips are now secured
with heavy bolts.
And 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.
Well, I think the morning that we
ditched, we were very fortunate,
because the outcome
could have gone horribly wrong.
But we survived. We got home.
My feelings that morning were,
this could never happen to me.
Now, when I fly in a chopper,
especially in winter time,
if it's going to be buffeted about
in the wind
I sometimes get the back of my mind,
this can happen to me again.
But we've all a choice.
We've all a choice to stop
or we carry on
and I'm still there 25 years later,
still earning a living.
The crash of Five Six Charlie
was a hair-raising incident
that could so easily
have ended in tragedy.
In the winter of 1995,
the skill of Commander Ced Roberts
and Flight 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 recognised their skill
and bravery in the emergency landing.
Although we received a number
of awards after the incident
from various organisations,
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 and 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."