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On 19 January 1995, lightning damages the tail rotor of Bristow Helicopters Flight 56C, forcing the crew to perform an emergency autorotation to a ditching in the sea. Despite the rough sea conditions, the 16 oil rig workers and 2 pilots are rescued by a nearby ship.
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00:021,000 meters above the frigid North Sea, disaster strikes.
00:09Mayday, mayday, 5, 6, Charlie.
00:12A helicopter is crippled in the middle of a sudden storm.
00:16The pilots struggle for control as it sinks helplessly towards the sea.
00:21They're far from land, off the radar screens.
00:24No one knows exactly where they are.
00:32In the days that follow, investigators search for the truth hidden in this tangled wreck.
00:38The cause of the crash shocks those involved and reveals a hidden danger that reaches far beyond the North Sea.
01:11The need for oil drives men to some of the most unpleasant places on Earth.
01:17This is one of them.
01:22The North Sea divides Britain from mainland Europe.
01:26It's a shallow sea, and the cruel winds that race across it can whip up enormous waves.
01:31The sea is cold, grey and violent.
01:37But there's oil out here, and so dozens of drilling platforms and thousands of men must face whatever the weather
01:44throws at them.
01:48The only efficient way to get the men out there is by helicopter.
01:52The flights are rough and long, up to 500 kilometers each way.
02:06After years, the trip has become largely routine, the danger below forgotten by many.
02:13What was that?
02:16But on a cold January morning in 1995, 18 men flying over the North Sea were faced with a horrible
02:23question.
02:24Mayday, mayday, mayday.
02:26Tail row to failure.
02:28Ditching.
02:29Could they survive in this extremely hostile environment?
02:34Oh, God.
02:36Oh.
02:41January the 19th, 1995.
02:44Commander Ced Roberts and First Officer Lionel Soule work for Bristow Helicopters in Aberdeen, Scotland.
02:50I'll just sign this tech log I see upstairs.
02:52OK, I'll download this flight and have a look at the weather.
02:54All right.
02:54Cheers.
02:55Their job is to ferry oil workers out to the oil platforms in the North Sea.
02:59By mid-morning, they've completed one trip already and are getting ready to head back out.
03:04Their helicopter is Super Puma 5-6 Charlie.
03:08While it's being checked out and refueled, Flight Officer Soule checks the flight logs and Commander Roberts goes through the
03:15weather reports, which are updated every two hours.
03:17Oh, weather's OK.
03:19Good for January.
03:21This is where they're heading, the North Sea.
03:25The discovery of oil here in the 1960s was a shot in the arm for the British economy.
03:31Brent Crude, as the oil is known, is a light, sweet crude, ideal for turning into gasoline, and its price
03:38is a benchmark on the international oil market.
03:47It helped turn Aberdeen, the Scottish port city closest to the oil rigs, into a boom town, the European oil
03:54capital.
03:58All the leading oil companies have offices here.
04:01The city is focused on getting the black gold ashore.
04:08Because the rigs are so far offshore, and the weather so unpredictable,
04:12helicopters are the only way to reliably ferry workers back and forth.
04:18Hundreds of thousands of people make the trip every year.
04:25The superpumas are one of the workhorses of the North Sea oil industry.
04:29Used around the world by industry and military, they're durable, tough, and made to withstand the elements.
04:37There are more of these helicopters flying offshore here than anywhere else in the world.
04:47The passengers heading to the platforms today gather in the heliport's departure lounge.
04:53They all work for the Texas company, Marathon Oil.
04:58The North Sea has scores of oil fields.
05:02They're divided up between several countries, including England and Norway.
05:07The governments then sell the rights to drill to a variety of oil companies.
05:12Marathon operates three platforms in the so-called Bray field.
05:16Bray East, Bravo, and Alpha.
05:21Out here, you're surrounded by the sea, with nowhere to go.
05:25The weather is often horrible, and the work on a rig can be rough, dirty, and dangerous.
05:32It's difficult to find and retain the skilled workers needed to pull the oil from the sea.
05:37So the platforms are built to keep the workers happy.
05:41Movies, internet cafes, gym equipment, even great food, are all provided by management to ensure the men are entertained.
05:50But there are strict rules, too.
05:53To protect the safety of everyone on board, there's no drinking, and smoking is severely restricted.
06:09One of Britain's worst disasters happened in the North Sea oil fields.
06:14In 1988, on Occidental Petroleum's Piper Alpha platform, the gas exploded and set fire to oil.
06:37167 men died.
06:42The potential for disaster is never far away.
06:45But on this January day, the marathon oil workers prepare as they always do.
06:51All 16 are scheduled to spend two weeks on Marathon's Alpha platform, followed by two weeks off.
07:00To these men, getting to work has become routine.
07:03But getting a ticket on this flight calls for something a little out of the ordinary.
07:12None of them is permitted to board a helicopter without first going through this, helicopter underwater escape training.
07:20Their lives may depend on knowing how to get out of a submerged helicopter or oil rig,
07:25and knowing what to do once they find themselves in the chilly North Sea.
07:34Several accidents over more than 20 years have driven home the point.
07:38Training may help a worker survive.
07:43Before they set off on every flight, they must watch the video,
07:46how to behave if there's an emergency on your flight.
07:50They've seen it all a thousand times.
07:53In an emergency, if time does not permit, just tighten your lap strap and brace for impact.
08:00To exit through the windows, pull the red tab to completely remove the rubber seal and push the window out.
08:10The passengers fasten their survival suits.
08:12Made of Gore-Tex, these dry suits won't keep them afloat,
08:16but are supposed to keep the water out if the workers are thrown into the sea.
08:22Their bright colors are also designed to make rescue easier.
08:27The trip to the Bray Alpha oil platform is 230 kilometers.
08:31If all goes well, it will take little more than an hour.
08:37The first part of their journey takes them northeast,
08:40along what's called the HMR, the helicopter main route.
08:45Then, 120 miles out, they'll reach an area called the Gate.
08:49That's where all the helicopters split up and go their separate ways to the individual oil platforms.
08:56Bray Alpha is about 40 kilometers from the Gate.
09:01For part of the journey, the radar operators at air traffic control
09:04in Aberdeen won't be able to see them.
09:09The reason why we lose low-level radar coverage out over the North Sea
09:13is, in essence, because the Earth is round.
09:16As a helicopter's flying outbound to an oil rig,
09:19it's actually following the curvature of the Earth.
09:23But radar pulses travel in straight lines,
09:26which means that as they travel further and further away,
09:28a gap opens up between the surface of the Earth and the radar waves.
09:32If an aircraft flies into that gap, then it'll disappear from radar.
09:36In the case of Aberdeen, a helicopter operating about 2,000 feet
09:40will disappear into that gap at about 80 miles.
09:44It's a black hole, which Super Puma 56 Charlie is now entering.
09:50The helicopter and the 18 men on board are over halfway to the rigs.
09:55And from this moment on, no one knows exactly where they are.
10:045-6 Charlie is a Super Puma helicopter
10:07serving the North Sea oil platforms off the coast of Britain.
10:11It's halfway through a long flight
10:12carrying 16 passengers to the Bray Alpha oil rig.
10:18The crew is getting concerned about what they see on their weather radar.
10:22The forecast called for scattered clouds,
10:25but the weather is changing fast.
10:29What do you think about this cloud?
10:31It's quite thin.
10:33Yeah, but look, we're getting some cumulus, too.
10:35It's quite small, about 100 yards across.
10:38Yeah, but it's developing a bit.
10:40Mm.
10:42Cumulus are puffy, white clouds like balls of cotton wool.
10:45They're beautiful to look at and usually harmless.
10:48They only last between 5 and 40 minutes.
10:52But helicopter pilots prefer to go above them if possible
10:55because the air inside and below gets very bumpy.
10:59Let's try to climb above it.
11:01Go to 5,000 feet.
11:02Right.
11:08Oh, look, there's a line of them.
11:10Follow along the route exactly where we're going.
11:13Yeah, we're not gaining anything by this.
11:15No.
11:15Let's drop back down to 3,000 feet.
11:17Right.
11:19So far, the weather is nothing to worry about.
11:22But over the North Sea, it can change suddenly.
11:27This corner of Europe is where the warm winds from the Atlantic
11:30meet the icy blasts from the Arctic and Siberia.
11:34The warm water vapour condenses into clouds, cools, then sinks.
11:38It creates strong winds, pushing the huge masses around.
11:42The friction caused by this motion can make the clouds electrically charged,
11:46and that electricity can be released as lightning.
11:49What starts out as a placid day can end up in a violent storm.
11:57It's now one hour after takeoff, and 5,6 Charlie is approaching the gate,
12:01the point where helicopters begin their descent to the individual oil platforms.
12:07They're 25 miles from their destination, and the weather is starting to get worse.
12:13Bray traffic, 5,6 Charlie, 120 miles on the 056 HMR.
12:18They make contact with Bray traffic watch located on one of the oil platforms.
12:22It handles all the comings and goings of helicopters.
12:25But Bray traffic doesn't have radar.
12:27It has to rely on the pilots to tell them where they are.
12:30Roger, 5,6 Charlie, I have your flight watch.
12:33Aberdeen information, Bristow's 5,6 Charlie at 120 miles.
12:38Leaving 3,000 feet, Bray has the flight watch.
12:41Roger, 5,6 Charlie, continue with Bray traffic.
12:45Quite suddenly, the weather has changed.
12:48Instead of the harmless fluffy balls of cotton wool,
12:52a line of dangerous cumulonimbus clouds is now blocking their path.
12:58Cumulonimbus, that's the granddaddy of all clouds.
13:00It stretches from around about 1,000 feet at its base all the way up to 28,000, 30,000
13:04feet.
13:05They are the most dangerous clouds that aircraft can come across,
13:07particularly small aircraft like helicopters.
13:10Within a cumulonimbus, you're going to find severe turbulence,
13:13you're going to find ice, and you're going to find heavy rain,
13:15and, of course, you're going to find lightning.
13:17If you're flying a helicopter, that's not where you want to be.
13:21Lightning is one of the most powerful forces of nature.
13:24Around the Earth, it strikes an average of 100 times per second,
13:28each strike with a power of up to a billion volts.
13:36Aircraft can't completely avoid it.
13:38On average, every passenger jet will be hit once a year by lightning.
13:43But the design of the planes helps prevent them being badly damaged.
13:47Their bodies are traditionally made of aluminium,
13:50which is a good conductor of electricity.
13:53The lightning passes harmlessly along the fuselage and exits from the tail.
13:59Helicopters use the same type of design to keep safe,
14:02and helicopters need it in the North Sea.
14:05With such stormy weather and so many helicopters,
14:09lightning strikes are inevitable.
14:12In fact, lightning hits the helicopter fleet in the North Sea 35 times a year.
14:20As they begin their descent,
14:22the super puma enters the line of clouds that stand in their path.
14:26Bits of cloud coming up here.
14:28No, it's okay. It's still green.
14:30Let's carry on through there.
14:33Green on the weather radar means there's rain,
14:35but it's not heavy enough to worry about.
14:37What the pilot sees in that is that it's simply like a television show,
14:41on that television screen he has a map,
14:43and overlaid on top of that map is a series of banded colours.
14:46If there's no rain, he has a blank map.
14:48If there's lots of rain and it's heavy,
14:50he has lots of red squares on that,
14:52and that gives you the idea of the intensity and the location of the rainfall.
14:57On board 5-6 Charlie, the weather gets more intense.
15:01They begin to get pelted by hail.
15:03Hey, where'd this come from?
15:06It's coming in through the vent.
15:10It's like being inside a beanbag swarmed by polystyrene balls.
15:13It's so thick.
15:15How come the engines are still running?
15:17There can't be any air left out there.
15:20Now another problem.
15:23We've got a hard over on the ice detector.
15:25It's probably just an ice pellet stuck in the probe.
15:27Right.
15:29The helicopter has an ice detector, a probe outside the craft,
15:33which is supposed to tell the pilots whether there's ice on the blades.
15:37But they think it's become jammed with ice and is giving a false reading.
15:43And then, disaster.
15:49Bloody hell.
15:50What was that?
15:51Lightning, I saw it.
15:55Well, this is bad.
15:57There's something very, very wrong with this.
15:58We'll have to go down, I'm afraid.
16:02The helicopter has been damaged, but they don't know how badly.
16:06The entire body is shaking and vibrating.
16:09The crew's first instinct is to get down to a lower altitude
16:12in case the worst happens and they fall out of the sky.
16:18Mayday, mayday.
16:19Five, six, Charlie.
16:20Lightning strikes.
16:21Severe vibration.
16:23Mayday, mayday.
16:49Fifty-six, Charlie.
16:56Gentlemen, my apologies, but we have to disembark you.
16:59We have an airborne emergency on a sister aircraft.
17:03Backhouse hurriedly unloads his passengers.
17:05He intends to help if he can.
17:10Meanwhile, a gale is steadily building up,
17:13with winds in excess of 70 kilometres an hour.
17:16The seas are mounting.
17:19The crew of Five-Six Charlie are struggling
17:21to keep control of their crippled helicopter.
17:24After the initial flash, though, the situation hasn't got worse.
17:28While closer to the sea,
17:30they continue to limp towards the platform.
17:34The Grampian Freedom is a standby ship
17:36positioned near the oil rigs
17:38to give oil workers a way to escape if anything goes wrong.
17:41Her skipper, John McInnes, hears the helicopter's distress call.
17:46We increased the speed to full speed ahead.
17:50Everybody was informed about the vessel
17:52and told to get ready for survivors to be taken aboard.
17:59Back on the Bravo platform,
18:01what was a routine flight for Brian Backhouse
18:04is about to become a rescue mission.
18:06He intends to find the stricken helicopter
18:08and nurse it to safety.
18:10If it crashes into the sea,
18:12he'll direct rescue ships to the spot.
18:16But they're not sure where to go.
18:19Let's go to the gate and proceed from there.
18:21At least they have a starting point.
18:26The Grampian Freedom doesn't know where to go either.
18:29They're getting conflicting messages
18:31about where Five-Six Charlie is.
18:33The helicopter's tiny size
18:36and the rough seas make it hard to find.
18:39On the damaged helicopter,
18:41Commander Roberts briefs the passengers.
18:44Gentlemen, you are obviously aware of the severe vibration.
18:47We've had a lightning strike,
18:48so please pull up your hoods,
18:50zip up your suits and prepare for a possible ditching.
18:54Countless hours of training
18:55is supposed to have prepared all on board
18:57for a moment like this.
18:59In a real emergency, how many will remember it?
19:041,200 feet. We're still flying.
19:07Their destination, the Bray Alpha platform,
19:10is now only 11 kilometers away.
19:13Three minutes have passed since the explosion,
19:15and things don't seem to be getting any worse.
19:18Let's try a few small inputs,
19:20make sure everything's working.
19:22Yes, we've got control in pitch.
19:24We've got control in roll.
19:28And we've got control in yaw.
19:31Tail rotor!
19:33The helicopter is beginning to spin round,
19:35a sure sign that something's happened to the tail rotor.
19:39The only thing the pilots can do to stop the spinning
19:42is to switch off the main rotor blade.
19:44Power off!
19:45Engine's on!
19:47Ditching has become inevitable.
19:595'6", Charlie is falling fast,
20:02more than 600 meters a minute,
20:04with the main rotor acting like a kind of parachute,
20:07the blades being turned only by the air
20:09that rushes through them.
20:12Mayday! Mayday!
20:14Tail rotor failure!
20:15Ditching!
20:15Brace for emergency landing!
20:17At this speed,
20:19they're about 40 seconds from hitting the North Sea.
20:25The other pilots in 5'6", Bravo,
20:27are searching in vain.
20:29There's no sign of 5'6", Charlie,
20:31in the sky or in the water.
20:36Then they hear another distress call.
20:38Mayday! Mayday!
20:40Tail rotor failure!
20:41Ditching!
20:42Mayday! Mayday! Mayday!
20:44relaying for 5'6", Charlie.
20:46We have a suspected tail rotor failure.
20:48He is ditching.
20:50Commander Backhouse in 5'6", Bravo,
20:52knows that he is closest to the stricken helicopter.
20:55Everything depends on him.
20:57But he's not equipped to locate the distress beacon
21:005'6", Charlie will use when it ditches.
21:03All he can do is search mile after mile of grey sea.
21:12Back on the Grampian Freedom,
21:14the crew begins searching the sea as well as the sky.
21:18But they know 5'6", Bravo can cover ground more quickly
21:22than the enormous, slow-moving ship.
21:24They do what they can and wait for better directions.
21:31Floats! Floats! I can't find the floats!
21:34I got it! I got it! Just keep it at trim angle.
21:36Right.
21:37The pilots of 5'6", Charlie are about to attempt
21:40one of the most difficult manoeuvres,
21:42ditching or landing in the middle of the heaving sea.
21:46Floats under the helicopter are meant to keep it from sinking.
21:50If they're deployed too soon before touchdown,
21:52the chopper may lose what little stability it has
21:55and topple over.
21:58Too late, and they won't inflate completely.
22:00Instead of riding the waves,
22:03the helicopter will sink below them.
22:05There's no second chance.
22:12They time it perfectly.
22:14We're down.
22:16Seems quite stable.
22:18They've landed safely,
22:19but no one knows if they will stay afloat.
22:24Helicopters are top-heavy,
22:25and they fear it could keel over and sink at any moment.
22:34They need to get the life rafts out,
22:36inflate them, and board them quickly.
22:38They fear that if the helicopter rolls over,
22:41it will trap them all inside.
22:44Lift that head!
22:45Hold it up!
22:49You go back and help with the evacuation.
22:51I'm going to shut things down here.
22:52I'm going to try one last mayday call.
22:54But the evacuation doesn't go smoothly.
22:57When they throw out one of the life rafts,
22:59the strong wind blows it back against the helicopter.
23:02They can't get into it.
23:04Get this one down.
23:05Can we go out the other side?
23:06It's better we all stay together anyway.
23:08Off you go!
23:09Go on!
23:09Go on!
23:10Go!
23:11Go!
23:13Mayday, mayday.
23:14Five, six, Charlie.
23:15We are on the water, floating, manning the dinghy.
23:18He doesn't mention their position.
23:20Make room!
23:21Get set!
23:22Make room!
23:23Make room!
23:23The raft is dangerously overloaded.
23:25There are 18 on board, and it's only meant for 14.
23:29Water is already up to their ankles and rising.
23:32Go on!
23:33Go on!
23:34They've crashed tantalizingly close to their destination.
23:37But once in the raft,
23:39they have no way of communicating where they are.
23:46For the first time,
23:48the pilots are able to see what caused the disaster.
23:51The rear rotor blade assembly and gearbox have broken off
23:54and are hanging down the side of the helicopter,
23:57held on by just a couple of pipes.
24:01No one realizes it yet,
24:03but in the rush,
24:04they've forgotten to bring the distress beacon with them from the helicopter.
24:08It sends out a signal that can be picked up by rescuers.
24:12Forgetting it could mean the difference between life and death.
24:18Two ropes attach the life raft to the helicopter.
24:21They're meant to stop the raft from drifting away,
24:24but they'll also drag them down if the helicopter sinks.
24:28One of the passengers has a knife.
24:30Shall I cut the line?
24:31No, not yet.
24:32We have a better chance of being spotted from close to the helicopter.
24:37Problems mount.
24:38The passengers are trying to raise the canopy to protect them,
24:42but it gets stuck.
24:44Without the canopy,
24:45they're at the mercy of the waves.
24:48And then,
24:49the helicopter itself becomes a danger.
24:52When the doors were jettisoned,
24:54they were supposed to be designed to slip down into the water and sink.
24:58Instead,
24:59one of them,
24:59which has a jagged edge,
25:01is floating on the surface
25:02and is heading straight for the raft.
25:05The life raft has been punctured by the floating door.
25:18The pilots do their best to put on a brave face.
25:21There are other helicopters and ships out there.
25:23They know we're down.
25:25They heard our mayday.
25:27The overloaded life raft is getting lower and lower in the water.
25:31Inside,
25:32it's already waist deep.
25:34Now,
25:34the pounding waves are pushing them beneath the sharp edges of the drooping helicopter blades.
25:40We need to get some distance.
25:42We'll have to cut the line.
25:44The two safety lines are still tying the life raft to the helicopter.
25:48One short,
25:49one long.
25:52They will cut the short one,
25:53so they can float further away from the menace of the rotor blades.
25:57The long line's been cut.
25:58It's been shredded.
26:02You'll have to cut the short one.
26:05The short line is the only thing attaching them to the helicopter.
26:09If they cut that,
26:10they'll quickly drift away,
26:11a tiny raft full of men at the mercy of the sea.
26:15But if they don't cut it,
26:16the jagged edges of the helicopter
26:18could tear their life raft to shreds
26:20and sink them all.
26:27Eighteen people have scrambled aboard a life raft
26:30after their helicopter crashed into the North Sea.
26:33The raft is overloaded.
26:35It's been punctured by the jagged metal edges of the helicopter door
26:38and is getting lower and lower in the water.
26:41They have to get away from the helicopter.
26:44Flight officer Lionel Soule takes the fateful decision
26:47and cuts the rope.
26:52They begin to drift away into the storm.
26:54The conditions are deadly.
26:59Most of their survival suits are leaking freezing water.
27:04For a person in the water,
27:06hypothermia can begin when the temperatures of air and water added together
27:09is below 50 degrees centigrade.
27:12In the North Sea in winter,
27:14the temperature is far below that.
27:18normal muscle and brain functions are quickly affected.
27:21The core body temperature will sink,
27:23followed by unconsciousness and death.
27:27Their chances of rescue are slim.
27:30No one knows where they are,
27:32just a tiny dot on a vast turbulent sea.
27:47The men are desperate.
27:50This could be their last chance.
27:54quickly,
27:54pass me those flares!
27:56Those flares!
27:58In the pocket behind you!
28:02Spud a flare,
28:04you fly bastard!
28:09But it's all in vain.
28:12The helicopter passes by.
28:16The men can't believe it.
28:19Their only hope is gone.
28:24On 56 Bravo,
28:26Brian Backhouse can see only grey seas.
28:29But suddenly,
28:30his co-pilot spots something.
28:32Contact!
28:33Right,
28:33two o'clock.
28:35OK, roger.
28:36Let's investigate.
28:49Target.
28:50Contact.
28:51Target confirmed.
28:5256 Charlie.
28:54Stand by for position report.
28:56Like a guardian angel,
28:5856 Bravo hovers directly above the survivors
29:01for over an hour,
29:02directing rescue boats and aircraft
29:04towards this tiny speck in the ocean.
29:07First to arrive is the Grampian Freedom.
29:10We had lookouts posted all around the vessel,
29:12some on top of the bridge,
29:13on each wing of the bridge.
29:17A helicopter came,
29:18and he started crisscrossing our bow,
29:21which is not a procedure,
29:22in that kind of situation.
29:26Almost a mile away from the raft,
29:28the Grampian Freedom launches its fast rescue boat.
29:31The boat sets off at full speed to the rescue.
29:35The rain and waves make finding the raft difficult.
29:40No, no, no, no, no, no,
29:42don't do this!
29:43Relax,
29:44because they know what they're doing.
29:46Let's go, quickly, go!
29:48The rescue boat throws a lifeline to the stranded men.
29:51They begin pulling themselves to safety.
29:54Fourteen survivors are taken back to the Grampian Freedom,
29:57four to another ship.
29:59The men are freezing cold and in a state of shock, but otherwise unharmed.
30:05Through their skill and against all the odds,
30:08Cedric Roberts and Lionel Soule have saved the lives of all on board.
30:13I must admit at the time I did think that was it, we were going to die.
30:16The whole world had changed from being really good
30:19to being what I thought was a complete disaster at that time.
30:24It was the worst situation I'd ever been in in the air,
30:26and I was very worried that that was going to be it.
30:32The crew had survived the ditching
30:34and kept the passengers safe until their rescue.
30:36But the day after the accident, they came under suspicion.
30:40Their report on what happened starts being questioned.
30:43Lightning, notionally at least,
30:45should not affect a very powerful North Sea helicopter.
30:48This is the first time I can recall a lightning strike
30:51having ended up with this kind of conclusion.
30:53The experts are sceptical of the pilot's story.
30:58No other helicopter is known to have crashed into the North Sea
31:02because of lightning.
31:04Perhaps there had been some mechanical failure.
31:06There were even whispers of pilot error,
31:09of recklessly flying into storm clouds.
31:13The evidence to support their story was now beneath the waves with 5-6-Charlie.
31:23The air accident investigation branch,
31:26Britain's air crash detectives,
31:28begins searching for the truth.
31:31It may look like a rig,
31:33but the stay-dive is actually a ship,
31:36mostly used for servicing oil platforms.
31:46It has nine powerful engines,
31:48which keep it stable in almost any weather.
31:54And it carries miniature submarines for underwater exploration.
31:58A day after the accident,
32:00it's brought in to find and raise the missing helicopter
32:03from the bottom of the North Sea.
32:07The investigation gets off to a good start.
32:10Within a day,
32:11the television cameras on board the stay-dive's two submersibles
32:14locate what's left of 5-6-Charlie on the seabed.
32:18But raising it is a different matter.
32:29They carry on working into the night.
32:32Soon, several pieces of 5-6-Charlie have been recovered,
32:35but still not the vital clue,
32:37the missing tail rotor.
32:39Ed Trimble was the AAIB's lead investigator.
32:44But the big problem was to recover the tail rotor assembly.
32:47Without that, the investigation was literally going nowhere.
32:51We knew that the tail rotor assembly
32:53had been dangling over the side of the pile
32:55and as the helicopter had ditched,
32:57and it had therefore detached at some point
32:59between the ditching
33:00and where we had caught up with the main wreckage.
33:04Keeping the stay-dive going
33:06would cost another £20,000 a day.
33:09Ed Trimble rang his boss.
33:12He was fairly sceptical of our chances.
33:15He asked what I thought our chances were
33:18of finding the tail rotor,
33:19and I, being an internal optimist,
33:21I said 80%, to which he replied,
33:24I think you'd be very lucky
33:25if you've got a 10% chance
33:27of recovering the tail rotor assembly in the North Sea.
33:30Ed Trimble stays up all night,
33:33relentlessly monitoring the underwater cameras.
33:38I didn't want to be in a situation
33:40where we would have missed any evidence
33:43of further wreckage,
33:44and in particular, any parts of the tail rotor assembly.
33:48Will you just have a coffee, Eddie?
33:49By the time 8 o'clock was looming,
33:52I decided to go down to the galley to get a coffee,
33:56and I couldn't have been away any more
33:58than maximum 7 to 10 minutes
34:00when I suddenly heard these tremendously excited shouts
34:05from our team.
34:06Yes, you, we found it!
34:09As I walked in, I ran in.
34:12There, smack in the middle of the screen,
34:14was the whole of the tail rotor assembly,
34:16and even at the first glance,
34:18I could see that one of the tail rotor blades
34:20showed clear evidence of a lightning strike.
34:24The crew was right.
34:26The submarine's cameras reveal telltale burn marks
34:29on the tail rotor blade.
34:32A close look at the wreckage on the deck
34:34reveals that two of the main rotor blades
34:36were also struck by lightning.
34:40But it's this tail rotor that suffered the most damage.
34:45Since lightning is not known to have forced a helicopter
34:48to crash into the North Sea before,
34:50the question is, why now?
34:53Ed Trimble called in lightning expert John Hardwick
34:57to discover just what had hit 5-6 Charlie.
35:01What we wanted to do with this set of tests
35:04was to take a set of tail rotor blades
35:06from the Super Puma helicopter
35:08and subject them to varying energy levels
35:11of simulated lightning strikes.
35:13The lightning objectives at Callum
35:15basically were to try and reproduce
35:20the degree of lightning damage
35:22in order to identify what kind of level of energy
35:26was associated with this particular strike.
35:30This home video of the tests
35:32was taken by Ed Trimble.
35:34Representatives of the company
35:35that makes the Super Puma were there too.
35:41Hardwick ran the blade
35:42through several lightning strikes
35:44until he was able to reproduce
35:46the damage found on the rotor blade.
35:51To do it, he had to generate
35:53a simulated strike of enormous power,
35:56something far more dangerous
35:57than anyone thought the helicopter would be exposed to,
36:00something that wasn't supposed to happen
36:02over the North Sea.
36:03There have been a few incidents over the years,
36:06minor strikes,
36:08a little bit of damage to the helicopter,
36:09but we never expected anything as severe
36:11as happened on that day.
36:14For one brief instant,
36:16it was more than all the electrical power
36:18being consumed in the entire United States.
36:21Some 30 billion watts.
36:27And this enormous flash of lightning
36:29had happened over the North Sea,
36:30where each year,
36:32almost 3 million passengers fly
36:34unsuspecting to the oil platforms.
36:38The helicopters we fly are certified
36:40to the highest standards.
36:41It's the same as you get on a major airline
36:43flying transatlantic.
36:44So we had no reason to believe
36:46that any lightning we had encountered
36:48would do any severe damage to the helicopter.
36:51Ordinary lightning wouldn't.
36:52But this wasn't ordinary.
36:59A lightning strike generates a huge pulse of energy.
37:03We can detect these pulses of energy
37:04via multiple transmitters and receivers
37:07that are situated throughout Europe.
37:09The information is calibrated locally,
37:11and once the position has been triangulated,
37:13that's passed to the Met Office in London.
37:18When the records were examined,
37:19they showed something very peculiar.
37:21This is what they think happened.
37:25Inside cumulonimbus clouds,
37:27tiny ice crystals are swept upwards
37:29by the wind currents.
37:30At the top of the cloud,
37:32where it's much colder,
37:33they combine with other crystals to form hail.
37:36The hail, being heavy, plummets back to Earth.
37:39On the way down,
37:41it hits the rising water crystals,
37:43causing friction.
37:44The crystals become electrically charged.
37:49When a helicopter enters the cloud,
37:51the sharp tips of its whirling rotor blades
37:54cut through these crystals,
37:55causing more friction,
37:57more electricity,
37:58until it's all released in a blinding flash.
38:04The record showed that the flash which hit 5-6 Charlie
38:08had been the only one recorded over the North Sea that day,
38:11caused almost certainly by the helicopter itself.
38:19However, for some reason,
38:21nearly all the damage had been confined to the tail rotor.
38:24What was it about the tail rotor
38:26that had made it especially vulnerable?
38:30Then, Ed Trimble made a remarkable discovery.
38:34When the Civil Aviation Authorities
38:36certified the Super Puma as safe,
38:38they had missed something important,
38:40something which may have caused 5-6 Charlie
38:43to fall from the sky.
38:49Safety investigators examined the wreckage of a helicopter,
38:52which crash-landed in the North Sea.
38:55As they study the ruined aircraft more closely,
38:58they uncover the cause of the accident.
39:03When the British Civil Aviation Authority
39:05laid down the lightning safety standards,
39:07they were looking at fiberglass blades,
39:10then the normal material for helicopter rotors.
39:14But in the 1980s,
39:16plane makers began using the new composite materials,
39:19like carbon fiber, which were lighter and stronger.
39:22In particular, they began making the new materials
39:24taking the rotor blades out of carbon fiber
39:26instead of fiberglass.
39:28It was assumed that the same standards
39:30would apply equally to the new blades.
39:33In the industry, that's known as reed across,
39:36and it's very dangerous.
39:39In fact, it was the very design of these composite blades
39:42which brought down 5-6 Charlie.
39:47Although made of carbon fiber,
39:49composite blades have a metal anti-erosion strip
39:52glued on to protect the edge.
39:54That's where the trouble starts.
39:57Carbon is a conductor of electricity,
39:59but it's a thousand times worse than aluminium,
40:01so you get a thousand times as much heat produced.
40:05The carbon blade gets very, very hot.
40:08And when the current meets the metal strip running along the edge,
40:13there is furious arcing and sparking
40:16until finally part of the erosion strip explodes.
40:23As little as a hundred grams of the erosion strip flew off,
40:26but it was enough.
40:28Without its weight, the rear rotor was unbalanced.
40:32That's what caused the vibration felt on board 5-6 Charlie
40:35immediately after the lightning strike.
40:40Three minutes later, when Lionel's soul tested out the controls,
40:43the unbalanced blades put the tail rotor under enormous stress.
40:48The bolts holding it on snapped.
40:54It was like a blowout in a car, only much, much worse.
40:58Things at that point were really very, very worrying.
41:02We both knew what had happened.
41:04We'd lost the tail rotor.
41:06And if you don't do exactly the right thing at that point,
41:09your life expectancy is very short.
41:11It's seconds.
41:12We had to do the right thing.
41:14We managed to point it into wind,
41:16and there was quite a big sea building up.
41:18And at 100 feet, I pulled back on the stick
41:21to flare the helicopter,
41:24slow down its rate of descent,
41:25and we were very fortunate at that point.
41:27A nice, friendly wave came along,
41:29and as I leveled the helicopter, a wave came up.
41:32We sat on the top of it, and we went down.
41:34And it was one of the best landings we've ever done,
41:36but that was luck more than judgment.
41:41As bad as it was, it could have been worse.
41:44The two hydraulic pipes connecting the assembly to the helicopter
41:47did not break.
41:49These two small diameter pipes had held the mass of the gearbox
41:54and tail rotor assembly dangling over the right side of the pylon.
42:00Without the weight of the rotor assembly,
42:02the helicopter would have tipped forward.
42:06Had that tail rotor gearbox and tail rotor assembly
42:09completely separated from the helicopter,
42:12then all 18 lives would have been lost,
42:15because the helicopter would have pitched down irrecoverably
42:18and gone into the North Sea.
42:23The investigators found the answer to the mystery of a helicopter crash.
42:27But they stumbled across a bigger problem,
42:30one that affects every air traveller.
42:41Investigators believe that 5-6 Charlie's violent end
42:44was caused by a savage lightning strike
42:46greater than anything it was built to withstand.
42:49And when the lightning hit,
42:51it exposed a problem in the carbon fibre blades
42:54that made them vulnerable.
42:56The tremendous heat created where the carbon fibre
42:59met the metal erosion strip could occur again.
43:05And the same type of violent reaction
43:08could hypothetically take place in any aircraft
43:10that has carbon fibre mixed with other materials.
43:16Increasingly, aluminium is being replaced with carbon fibre.
43:20The world's largest plane, the A380 Airbus, for instance,
43:23has over 20%.
43:25Its rival from Boeing, the Dreamliner,
43:28will contain 50% carbon fibre.
43:32What will happen if these planes encounter
43:34a monster lightning strike?
43:36This was the investigators' biggest concern
43:39arising out of this super-puma accident.
43:43The findings were unexpected
43:45and treated with some scepticism.
43:48Though the tests indicated
43:49that an unexpectedly large lightning strike
43:52hit 5-6 Charlie,
43:53Britain's Civil Aviation Authority refused to accept it.
43:59The tests were not proof.
44:01There was no way to know for sure
44:03how powerful the lightning was
44:04that hit the helicopter.
44:06No action was taken
44:08to increase the safety standards
44:10that these helicopters must meet.
44:12I thought that the reaction was poor.
44:16There seemed to be a real reluctance
44:20on their behalf to accept the evidence.
44:24If Britain's air crash detectives are right,
44:27there is a real concern facing air travellers.
44:31Flashes of lightning far greater
44:33than aircraft are supposed to encounter
44:34are possible.
44:35And aircraft made of newer composite materials
44:38are at increased risk.
44:43For the super-puma, though,
44:45the lessons have been learned.
44:47The design of the rotor blades
44:48has been vastly strengthened.
44:51The erosion strips are now secured
44:53with heavy bolts.
44:54And pilots have been instructed
44:56to give storm clouds a wider berth.
45:01The men who must fly these machines to work
45:04are prepared to accept the risks.
45:06Well, I think the morning there we ditched,
45:08we were very, very fortunate
45:10because the outcome could have gone horribly wrong.
45:13But we survived, we got home.
45:17My feelings of that morning was
45:19this could never happen to me.
45:21Now, when I fly in the chopper,
45:23especially in the wintertime,
45:24if it's going to be buffed about with wind,
45:26I sometimes get the, in the back of your mind,
45:29this can't happen to me again.
45:30But we've all a choice.
45:32We've all a choice either to stop
45:33or we carry on.
45:34And I'm still there 25 years later,
45:37still there in an elephant.
45:39The crash of 5-6 Charlie
45:41was a hair-raising incident
45:43that could so easily have ended in tragedy.
45:48In the winter of 1995,
45:51the skill of Commander Sed Roberts
45:52and Flight Officer Lionel Sol
45:54saved the lives of their 16 passengers.
46:00Roberts and Sol receive an award for their work.
46:05The Guild of Air Pilots and Air Navigators
46:07recognised their skill and bravery
46:09in the emergency landing.
46:12Although we received a number of awards
46:14after the incident
46:17from various organisations,
46:19one thing I received,
46:20which is far more precious to me
46:22than any of them,
46:22was from the daughters of one of my passengers.
46:25It was this little card.
46:27It says,
46:28Dear Captain Roberts,
46:29I can't tell you how much I need to thank you
46:32after you saved my dad's life.
46:35It took a lot of effort
46:36to try to keep calm
46:37while you were falling.
46:39If you hadn't have got that helicopter in control,
46:42my dad maybe wouldn't be here today.
46:44Thank you very, very, very much.
46:47Thank you very much.
46:48Thank you very much.