Original subtitles

Narrator: SUDDEN IMPACT AND SCORCHING FLAMES.

Niki Lauda: I THOUGHT, AM I GONNA DIE?

Narrator: A FIERY CRASH NEARLY KILLS A RACING LEGEND.

Lauda: THANK GOD I MADE IT THROUGH.

Narrator: BUT FOR RACE CAR DRIVER TURNED AIRLINE OWNER NIKI LAUDA,

A MORE DEVASTATING ACCIDENT IS STILL TO COME.

Lauda: I GOT A PHONE CALL FROM THE NEWS.

THEY SAID ONE OF YOUR AIRPLANES CRASHED.

Pilot: UGH! DAMN IT!

Man: WE JUST COULDN'T FIND THE SMOKING GUN.

Narrator: AUSTRIA'S FAMOUS CHAMPION DEFIES CONVENTIONAL WISDOM...

Lauda: IF THEY HAD LOST ONLY 10% THEY WOULD STILL BE HERE.

Narrator: ...FIGHTS TO UNCOVER THE TRUTH.

Lauda: IT'S MY NAME, MY AIRPLANE, MY CRASH.

Narrator: ...AND DISCOVERS A NEW AND WIDESPREAD THREAT

TO MODERN AVIATION.

Flight attendant: LADIES AND GENTLEMEN, WE ARE STARTING OUR APPROACH.

Pilot: WE LOST BOTH ENGINES!

Flight attendant: PUT THE MASK OVER YOUR NOSE.

EMERGENCY DESCENT.

Pilot: MAYDAY, MAYDAY.

Flight attendant: BRACE FOR IMPACT!

Controller: I THINK I LOST ONE.

Man: INVESTIGATION STARTING...

Man: HE'S GONNA CRASH!

Josef Thurner: YOU NEED A LITTLE BIT OF RUDDER TRIM TO THE LEFT, HUH?

Thomas Welch: WHAT'S THAT?

Thurner: YOU NEED A LITTLE BIT OF RUDDER TRIM TO THE LEFT.

Welch: OK.

Narrator: CAPTAIN THOMAS WELCH AND FIRST OFFICER JOSEF THURNER

ARE FLYING A BOEING 767

FROM BANGKOK, THAILAND, TO VIENNA, AUSTRIA.

THE FLIGHT IS OPERATED BY LAUDA AIR,

THE BRAINCHILD OF FAMED AUSTRIAN FORMULA ONE DRIVER NIKI LAUDA.

Lauda: FOR ME IT WAS A LOGICAL STEP AFTER RETIRING FROM RACING

TO START IN THIS KIND OF BUSINESS,

AND THAT'S WHAT I DID WITH LAUDA AIR.

Narrator: THROUGHOUT THE '70s, LAUDA DOMINATED FORMULA ONE RACING.

Herbert Volker: NIKI WAS THE BEST DRIVER IN HIS DAYS.

Commentator: NIKI LAUDA'S FERRARI IS STILL IN THE LEAD.

Volker: I THINK NIKI IS THE BEST KNOWN AUSTRIAN

SINCE MOZART.

Commentator: AND THAT'S HOW THEY FINISH.

NIKI LAUDA TAKES THE FLAG.

Narrator: HE WON THE WORLD CHAMPIONSHIP THREE TIMES,

THEN USED HIS FAME TO LAUNCH A NEW CAREER AND A NEW AIRLINE.

Lauda: ONE OF THE MAIN REASONS WAS TO GIVE THE PASSENGERS

A DIFFERENT WAY OF FLYING, BETTER SERVICE, BETTER FOOD.

THE AIRPLANE HAD TO LOOK IN A CERTAIN WAY.

Narrator: THE LAUDA AIR 767 IS LESS THAN 15 MINUTES

INTO ITS 11-HOUR FLIGHT TO VIENNA.

IT'S A ROUTE NIKI LAUDA KNOWS FIRST-HAND

BECAUSE HE'S NOT JUST THE OWNER OF THE AIRLINE,

HE'S ALSO ONE OF ITS PILOTS.

Lauda: WHEN YOU RUN A COMPANY AND YOU FLY, IT'S VERY SIMPLE,

BECAUSE WHEN YOU ARE WITH YOUR PASSENGERS

THEN YOU KNOW WHAT IS GOING ON.

YOU CAN LOOK YOURSELF WHAT THE PROBLEMS ARE,

AND I CORRECTED THINGS QUICKER IN THAT WAY.

Narrator: IN THE COCKPIT,

CAPTAIN WELCH AND FIRST OFFICER THURNER

MONITOR THEIR INSTRUMENTS

WHILE THE AUTOPILOT CONTROLS THE CLIMB.

Welch: AH! OH!

Narrator: SUDDENLY, THE PLANE BEGINS DROPPING FROM THE SKY.

Welch: CHRIST!

WAIT A MINUTE.

AH! DAMN IT!

Narrator: THE PILOTS HAVE LOST CONTROL.

LAUDA FLIGHT 4 IS PLUMMETING TO EARTH.

THE PLANE SLAMS INTO A REMOTE JUNGLE

110 MILES NORTHWEST OF BANGKOK.

Lauda: I WAS AT HOME, AND I HAD A PHONE CALL

FROM THE NEWS STATION HERE IN VIENNA,

AND THEY SAID ONE OF YOUR AIRPLANES CRASHED.

Narrator: WHEN RESCUERS ARRIVE,

IT'S IMMEDIATELY OBVIOUS THAT THERE'S NO ONE TO BE RESCUED.

ALL 213 PASSENGERS AND 10 CREWMEMBERS ARE DEAD.

Lauda: THE AIRPLANE TOOK OFF AT 16:01 UTC.

THERE WAS NO FAULT OR WHATEVER REPORTED FROM THE PILOTS.

THE AIRPLANE FLEW ABOUT 20 TO 25 MINUTES

AND THEN SUDDENLY DISAPPEARED OFF THE RADAR SCREEN,

SO WE HAVE NO INDICATION WHATSOEVER,

WHATSOEVER HAPPENED TO THE AIRPLANE.

Narrator: IT'S THE FIRST TIME A BOEING 767 HAS EVER CRASHED.

THE LOSS OF A U.S.-MADE AIRCRAFT PROMPTS QUICK ACTION

FROM THE NATIONAL TRANSPORTATION SAFETY BOARD.

THE NTSB IMMEDIATELY SENDS

VETERAN INVESTIGATOR BOB MACINTOSH TO THAILAND.

Bob Macintosh: THE FIRST CRASH OF AN AIRCRAFT

THAT WAS IN SERVICE INTERCONTINENTALLY

FOR ALMOST A DECADE WITH A PERFECT SERVICE RECORD.

IT WAS EXTREMELY IMPORTANT FOR US TO LEARN WHAT HAD HAPPENED.

Narrator: 223 PEOPLE ARE DEAD,

AND ONE OF THE WORLD'S MOST POPULAR PLANES

LIES IN PIECES IN A REMOTE THAI JUNGLE.

Macintosh: MOST OF THE TERRITORY WAS A MOUNTAINOUS,

VERY TROPICAL-TYPE TERRITORY.

WE RECOGNIZED THAT WE WERE GONNA HAVE A MAJOR CHALLENGE

TRYING TO IDENTIFY ALL THE COMPONENTS.

Narrator: THE DIFFICULT TERRAIN ISN'T THE ONLY PROBLEM

THE INVESTIGATORS ARE FACING.

Macintosh: THERE WERE NUMEROUS LOCAL FOLKS AROUND,

AND UNFORTUNATELY THEY WERE NOT CONTROLLED BY THE LOCAL POLICE.

THERE WAS LOOTING AND TREASURE HUNTING

GOING ON AROUND THE CRASH SITE.

FIRST THING WE GOT TO DO IS PUT A STOP TO THAT.

Narrator: LOOTERS ARE SWARMING THE WRECKAGE,

AND VITAL EVIDENCE IS IN DANGER OF DISAPPEARING.

Macintosh: IT WAS OF GREAT CONCERN TO US

THAT CRITICAL PARTS MIGHT HAVE BEEN TAKEN AWAY FROM THE SITE

SIMPLY BY FOLKS WHO DIDN'T UNDERSTAND

THE CRITICALITY OF THAT EVIDENCE.

Narrator: THE BADLY BURNED WRECKAGE

IS STREWN OVER A SQUARE MILE OF ROUGH TERRAIN.

Macintosh: WE WERE CONFRONTED WITH WHAT APPEARED TO BE

EVIDENCE OF A INFLIGHT BREAKUP

IN THAT THE MAJOR COMPONENTS,

THE COCKPIT, THE TAIL, THE MAIN BODY,

THEY WERE SCATTERED FAR ENOUGH APART

THAT CERTAINLY THEY HAD NOT COME DOWN TOGETHER.

Narrator: THE LARGE FIELD OF DEBRIS LEAVES MACINTOSH WITH LITTLE DOUBT.

THE 767 BROKE UP IN MIDAIR, NOT WHEN IT HIT THE GROUND.

WHAT COULD HAVE CAUSED THAT?

Macintosh: SO IT SOUNDED LIKE AN EXPLOSION.

Narrator: WITNESSES SAY THE PLANE BLEW UP

AND CAME DOWN ENGULFED IN FLAMES.

THE EVIDENCE IS POINTING TO A TROUBLING POSSIBILITY--

THAT LAUDA AIR FLIGHT 4 WAS BROUGHT DOWN

BY A DELIBERATE ACT OF SABOTAGE.

Macintosh: THERE WAS A LOT OF SPECULATION

ABOUT THE POSSIBILITY OF A TERRORIST ACT

AFFECTING THE AIRCRAFT.

GLAD TO HAVE YOU ON BOARD.

LET ME SHOW YOU WHERE WE'RE AT SO FAR.

THIS IS FRED.

Narrator: BOEING SENDS ITS OWN INVESTIGATOR TO THAILAND.

KEVIN DARCY HAS AN INTIMATE KNOWLEDGE OF THE 767--

HE HELPED DESIGN THE PLANE.

HE, TOO, SUSPECTS THAT THIS COULD BE A CASE OF FOUL PLAY.

Kevin Darcy: IT IS PRETTY UNUSUAL FOR AN ACCIDENT TO OCCUR

ON THE EARLY CLIMB-OUT PORTION OF THE FLIGHT.

MY INITIAL THOUGHT WAS THAT IT WAS SOME SORT OF SABOTAGE

OR A MISSILE OR SOMETHING LIKE THAT.

Narrator: IT'S BEEN JUST THREE MONTHS SINCE WESTERN POWERS

PUSHED SADDAM HUSSEIN OUT OF KUWAIT IN THE PERSIAN GULF WAR.

THE TIMING SPARKS RUMORS OF A REVENGE PLOT,

A TERRORIST ATTACK AGAINST A SOFT TARGET--LAUDA AIR.

Darcy: THEY POP INTO YOUR MIND, IDEAS LIKE THAT,

AND YOU HAVE TO WORK KIND OF HARD

TO GET THOSE OUT OF YOUR MIND

SO YOU CAN JUST SEE WHERE THE FACTS TAKE YOU.

Narrator: THE PASSENGER LIST SUGGESTS A POSSIBLE LEAD.

ONE OF THE PEOPLE TRAVELING ON FLIGHT 4 WAS AN ADVISOR

TO THE UNITED NATIONS DRUG CONTROL PROGRAM.

DONALD MACINTOSH WAS HELPING THE THAIS FIGHT A WAR ON HEROIN.

PERHAPS THE POWERFUL DRUG BARONS

WHO RULE THAILAND'S GOLDEN TRIANGLE

HAVE SOMEHOW ENGINEERED THE DISASTER.

INVESTIGATORS BEGIN THE PAINSTAKING TASK

OF TESTING THE WRECKAGE FOR EXPLOSIVE RESIDUE.

AIRLINE OWNER NIKI LAUDA IS RELUCTANT

TO BELIEVE TERRORISM BROUGHT DOWN ONE OF HIS PLANES.

HE ARRIVES IN THAILAND TO SEE FOR HIMSELF.

Lauda: MY FIRST DECISION WAS TO GO THERE MYSELF

AND TRY TO FIND OUT WHAT HAPPENED,

AND THIS IS WHAT I DID.

WHERE WAS THE TAIL FOUND?

I'VE NEVER SEEN AN AIRPLANE CRASH IN ALL MY LIFE.

THE SCENE FOR ME,

THIS WAS THE MOST HORRIFIC PICTURES I'VE EVER SEEN.

Narrator: SURROUNDED BY THE SCATTERED REMAINS

OF AN AIRLINER THAT CARRIED HIS NAME,

LAUDA IS OVERWHELMED BY THE MAGNITUDE OF THE DISASTER.

Lauda: WHEN YOU HAVE 223 PEOPLE KILLED,

THE FAMILIES ALL WANT TO KNOW WHY.

AND I THINK THIS IS THE WORST FOR PEOPLE

IF THEY DO NOT KNOW WHY THEY LOST THEIR HUSBAND,

CHILDREN OR WHATSOEVER.

Narrator: LAUDA IS DETERMINED TO FIGURE OUT WHAT WENT WRONG.

Lauda: IF IT'S THE FAULT OF LAUDA AIR TECHNICIANS OR PILOTS,

I AM RESPONSIBLE FOR EVERYBODY.

I WOULD CERTAINLY RESIGN.

Narrator: HIS CONVICTION MAY BE ROOTED

IN HIS OWN TRAUMATIC PAST.

AT THE GERMAN GRAND PRIX IN 1976,

HIS FERRARI SLAMMED INTO A WALL AND ERUPTED IN FLAMES.

LAUDA SUFFERED THIRD-DEGREE BURNS TO HIS HEAD AND BODY.

HE BARELY SURVIVED.

Lauda: AND I SAID, I'M NOT GONNA DIE,

AND THANK GOD I MADE IT THROUGH,

BUT IT WAS VERY TOUCH AND GO, NOT BECAUSE OF MY BURNS.

IT WAS MY LUNG DAMAGE WHICH WAS THE PROBLEM.

Narrator: HIS LUNGS WERE BADLY SCARRED

FROM INHALING TOXIC, BURNING FUMES.

BUT IN SPITE OF HIS INJURIES, LAUDA ONLY MISSED TWO RACES.

Reporter: JUST 40 DAYS AFTER DOCTORS HAD GIVEN UP HOPE

AND A PRIEST HAD KNELT AT HIS BEDSIDE,

THE AUSTRIAN ACE CLIMBED BACK INTO THE COCKPIT

OF HIS GLARING RED FERRARI.

Narrator: HE WAS BACK ON THE TRACK SIX WEEKS LATER.

BUT THE CAUSE OF HIS NEAR FATAL CRASH WAS NEVER UNCOVERED.

THIS TIME, HE WANTS THINGS TO BE DIFFERENT.

Volker: AFTER THE CRASH NEAR BANGKOK,

THE ONLY WAY FOR HIM TO SURVIVE AS AN INTACT PERSON

WAS TO FIND OUT WHAT REALLY HAD HAPPENED.

Narrator: FINDING ANSWERS WON'T BE EASY.

EARLY EVIDENCE FROM THE CRASH SITE

IS ALREADY RAISING DOUBTS ABOUT THE BOMB THEORY.

Macintosh: ONE OF THE MOST IMPORTANT SIGNATURES

IN LOOKING AT TERRORISM

IS TO LOOK AT THE BAGGAGE CONTAINERS IN AN AIRCRAFT

AND SEE IF THEY'RE DAMAGED IN ANY WAY

AND WHAT THAT DAMAGE IS,

IF THERE ARE SIGNATURES OF EXPLOSIONS.

I DON'T KNOW.

THERE'S NO CHARRING.

THERE'S NO OUTWARD PETALING.

DOESN'T SAY BOMB TO ME.

WE DIDN'T SEE ANY EVIDENCE OF TERRORISM.

Narrator: THE BLACK BOXES MAY HAVE CAPTURED IMPORTANT CLUES

ABOUT THE CAUSE OF THE INFLIGHT BREAKUP,

BUT THEY'RE BADLY BURNED.

TO HAVE ANY HOPE OF RETRIEVING THE DATA,

THAI INVESTIGATORS NEED TO SEND THE BOXES

TO A SOPHISTICATED LAB.

BOB MACINTOSH MAKES THE CASE FOR THE NTSB TO GET THE JOB.

Macintosh: THEY SHOULD GO TO WASHINGTON.

THERE WAS AN OBVIOUS REASON,

AND IT WAS BECAUSE THE AIRCRAFT

WAS CERTIFIED BY THE UNITED STATES, FAA,

AND THE MANUFACTURER IS LOCATED IN THE UNITED STATES.

Narrator: DAYS AFTER THE CRASH, CRUCIAL PIECES OF THE PLANE

ARE STILL MISSING, INCLUDING THE ENGINES.

Macintosh: TRACKING DOWN THE WRECKAGE

AT THE LAUDA CRASH SITE WAS CERTAINLY A MAJOR CHALLENGE.

IT WAS MOUNTAINOUS. IT WAS TOTALLY OVERGROWN.

WE CLIMBED A MOUNTAIN, WENT BACK DOWN IN A VALLEY

AND FOUND THE LEFT ENGINE.

WELL, WOULD YOU LOOK AT THAT.

Narrator: THEN, INVESTIGATORS SEE SOMETHING

THAT SENDS A CHILL THROUGH THE AVIATION WORLD.

INVESTIGATORS IN THAILAND HAVE MADE A SURPRISING FIND.

THE THRUST REVERSER ON FLIGHT 4'S LEFT ENGINE

IS FULLY DEPLOYED.

Darcy: ONCE WE ACTUALLY SAW

THAT THE THRUST REVERSER HAD DEPLOYED,

FOR ME IT WAS, IT WAS SHOCKING.

IT WAS NOT ANYTHING I REALLY EXPECTED WOULD HAPPEN.

Narrator: THRUST REVERSERS HELP JETLINERS

COME TO A STOP ON LANDING.

THEY WORK BY REDIRECTING ENGINE THRUST FORWARD

TO SLOW THE PLANE DOWN.

Macintosh: LEFT SIDE DEPLOYED IN MIDAIR.

NO DOUBT.

Narrator: PLANES HAVE BUILT-IN SAFEGUARDS

TO PREVENT REVERSERS FROM DEPLOYING DURING FLIGHT.

BUT EVEN IF IT DOES HAPPEN, IT SHOULDN'T CAUSE A CRASH.

Darcy: THE WIDESPREAD FEELING OF WHAT WOULD HAPPEN

IF A REVERSER DEPLOYED IN FLIGHT

WAS THAT THE AIRPLANE WOULD BE CONTROLLABLE,

THAT YOU COULD MAKE A SAFE LANDING AFTER THAT HAPPENED.

Narrator: IN FACT, FLIGHT TESTING HAS ALREADY SHOWN EXACTLY THAT.

BEFORE THE 767 FIRST WENT INTO SERVICE,

BOEING HAD TO PROVE THAT PILOTS COULD KEEP FLYING SAFELY

AFTER A MIDAIR DEPLOYMENT.

Darcy: I WAS ACTUALLY ON ONE OF THE FLIGHT TESTS

WHEN WE TESTED THE THRUST REVERSER DEPLOYED.

THERE WAS A LOT OF VIBRATION, A LOT OF NOISE,

BUT THE AIRPLANE WAS CONTROLLABLE.

Narrator: THE PILOTS ONLY EXPERIENCED A SMALL LOSS OF LIFT.

AS A RESULT, BOEING CERTIFIED THE 767

AS CAPABLE OF CONTINUED SAFE FLIGHT AND LANDING

UNDER ANY POSSIBLE POSITION OF THE THRUST REVERSER.

BUT THE DISCOVERY OF AN ENGINE WITH A DEPLOYED REVERSER

IS SO UNUSUAL,

INVESTIGATORS MUST CONCLUDE

THAT IT'S SOMEHOW RELATED TO THE CRASH.

Macintosh: HOW DOES A THRUST REVERSER BRING DOWN A 767?

WE'RE MISSING SOMETHING.

Narrator: IF IT TURNS OUT THAT A FAULTY THRUST REVERSER

CAN BRING DOWN A PLANE,

IT HAS OMINOUS IMPLICATIONS FOR THE ENTIRE AIRLINE INDUSTRY.

THE LIVES OF HUNDREDS OF THOUSANDS OF PASSENGERS

AROUND THE WORLD COULD BE IN JEOPARDY.

Macintosh: WE RECOGNIZED THAT WE HAD SOMETHING

THAT WAS VERY UNUSUAL AND WOULD, WOULD REQUIRE A LOT OF ANALYSIS.

Narrator: THE DEPLOYED THRUST REVERSER

IS THE STRONGEST LEAD INVESTIGATORS HAVE.

BUT NO ONE CAN FIGURE OUT HOW IT COULD HAVE CAUSED THE CRASH.

Macintosh: WHAT WOULD HAVE CAUSED THE LOSS OF CONTROL

OF THE AIRCRAFT,

BECAUSE IT HAD BEEN DEMONSTRATED

THAT THIS VERY CONDITION COULD BE, COULD OCCUR IN THE AIR

AND YOU COULD CONTINUE TO LAND.

Narrator: INVESTIGATORS WILL HAVE TO SOLVE THE MYSTERY

WITHOUT THEIR MOST VALUABLE TOOL.

THE FLIGHT DATA RECORDER IS SO BADLY BURNED

THAT TECHNICIANS AT THE NTSB CAN'T RECOVER ANY DATA.

Lauda: THE DISAPPOINTMENT WAS THE FLIGHT DATA RECORDER

WAS COMPLETELY DESTROYED, WHICH WAS VERY UNLUCKY.

Narrator: BUT THERE'S BETTER NEWS ABOUT THE COCKPIT VOICE RECORDER.

IT HAS SURVIVED THE FIRE.

Macintosh: READY TO GO?

Narrator: INVESTIGATORS ON BOTH SIDES OF THE WORLD

CAN FINALLY LISTEN TO THE LAST MOMENTS

OF LAUDA AIR FLIGHT 4.

Thurner: AVIONICS? Welch: CHECK.

Lauda: FOR ME IT WAS VERY IMPORTANT TO LISTEN TO THE VOICE RECORDER

TO UNDERSTAND THINGS IN A BETTER WAY,

BECAUSE YOU NEED ANSWERS.

Thurner: V-1. ROTATE.

Macintosh: WE RECOGNIZED THAT THE FIRST OFFICER

HAD BEEN IN THE PILOT MONITORING POSITION.

THE CAPTAIN WAS FLYING THE AIRCRAFT.

Thurner: POSITIVE RATE OF CLIMB.

Welch: GEAR UP.

Narrator: THE VOICE RECORDER SHOWS A NORMAL TAKEOFF AND CLIMB.

Thurner: LANDING GEAR'S UP.

Lauda: ALL THIS KIND OF NORMAL COMMUNICATION,

WHICH I KNEW ALL THE PEOPLE, SO FOR ME IT WAS HONESTLY HARD.

THIS WAS THE HARDEST PART OF ALL MY LIFE.

Thurner: WE ARE CLEAR TO LEVEL 3-1-0

AND MAINTAINING, LAUDA 4.

Narrator: FLIGHT 4 CLIMBS TO 7,000 FEET WITHOUT A PROBLEM.

A LITTLE MORE THAN FIVE AND A HALF MINUTES INTO THE FLIGHT,

THE FIRST HINT OF TROUBLE.

Thurner: SCHEISSE.

Welch: YEAH, THAT KEEPS... IT'S COME ON.

Macintosh: WHAT'S COME ON?

Lauda: SOME KIND OF WARNING.

Narrator: THE PILOTS HAVE NOTICED AN ALERT THAT'S COMING ON IN THE COCKPIT.

COULD THIS BE THE CLUE

THAT UNLOCKS THE MYSTERY OF LAUDA FLIGHT 4?

INVESTIGATORS LISTEN AS THE LAUDA PILOTS DISCUSS

A MYSTERIOUS COCKPIT WARNING.

Welch: WHAT'S IT SAY IN THERE ABOUT THAT?

Thurner: ADDITIONAL SYSTEM FAILURES MAY CAUSE INFLIGHT DEPLOYMENT.

EXPECT NORMAL REVERSE OPERATION AFTER LANDING.

Woman: STOP IT FOR A SECOND.

"ADDITIONAL SYSTEM FAILURES MAY CAUSE INFLIGHT DEPLOYMENT."

HE'S TALKING ABOUT THE REVERSER ISOLATION VALVE WARNING.

Narrator: THE WARNING RELATES TO A VALVE

IN THE LEFT ENGINE'S THRUST REVERSER.

THE HYDRAULIC ISOLATION VALVE CONTROLS THE FLOW

OF HYDRAULIC FLUID TO THE REVERSERS.

WHEN IT'S OPEN, THE REVERSER CAN BE STOWED OR DEPLOYED.

WHEN IT'S CLOSED, THE REVERSERS WON'T BUDGE.

Welch: OK.

Narrator: THE CREW DOESN'T SOUND WORRIED ABOUT THE WARNING.

Macintosh: THE REVERSE ISOLATION WARNING

THAT WAS PRESENTED TO THE CREW

WAS AN ABNORMAL BUT NOT EMERGENCY ISSUE,

AND IT DIDN'T REQUIRE ANY ACTION BY THE CREW

OTHER THAN TO BE ADVISED THAT THE THRUST REVERSE

MIGHT NOT BE AVAILABLE ON LANDING.

Welch: OK.

Lauda: THEY DID THE RIGHT THING.

THEY READ THE CHECKLIST,

AND THE CHECKLIST SAID YOU CAN CONTINUE THE FLIGHT.

Thurner: SHOULD I ASK THE GROUND STAFF?

Welch: NO. IT'S PROBABLY MOISTURE OR SOMETHING

'CAUSE IT'S NOT JUST ON, IT'S COMING ON AND OFF.

Thurner: YEAH.

Macintosh: IT WAS A NON-EMERGENCY ISSUE,

AND THEY SIMPLY DISCUSSED IT.

Welch: YOU KNOW IT DOESN'T REALLY,

WELL, IT'S JUST AN ADVISORY THING.

Macintosh: TO MAKE SURE THAT THEY FELT COMFORTABLE

THAT IT WAS NOT SOMETHING

THAT WAS GOING TO INTERFERE WITH THE FLIGHT.

Welch: I DON'T...UH...

IT COULD BE SOME MOISTURE IN THERE OR SOMETHING.

Narrator: FOR FIVE MINUTES, NOTHING HAPPENS.

THEN...

Welch: UGH! OH!

Thurner: REVERSER'S DEPLOYED.

Welch: OH, CHRIST!

HERE. WAIT A MINUTE.

AH! DAMN IT!

Lauda: THE CAPTAIN SAID "DAMN IT,"

AND REACTIONS OF A PILOT WHICH IS OUT OF CONTROL BASICALLY.

THE CO-PILOT DIDN'T SAY A WORD IN THESE MOMENTS OF THE CRASH.

SO FOR ME IT WAS VERY OBVIOUS

THAT SOMETHING MUST HAVE HAPPENED THERE SO QUICKLY

BECAUSE NORMAL PILOTS, THEY COMMUNICATE WITH EACH OTHER

IF THERE IS A PROBLEM.

Narrator: THE CVR CONFIRMS THAT WHATEVER WENT WRONG

HAPPENED INCREDIBLY FAST.

JUST 22 SECONDS LATER,

THE SOUND OF THE PLANE BEING RIPPED TO PIECES.

Lauda: THE WHOLE THING WAS SO DIFFICULT.

YOU, YOU NEVER FORGET.

Volker: NIKI KNEW THAT IT HAD TO BE A MISTAKE

WHICH WAS NOT THE AIRLINE'S MISTAKE,

NOT NIKI'S MISTAKE, AND NOT THE PILOTS' MISTAKE.

Narrator: NIKI LAUDA IS CONVINCED

THE DEPLOYED THRUST REVERSER IS WHAT CAUSED THE CRASH.

Volker: THE MOMENT NIKI WAS SURE

THAT THERE WAS SOMETHING WRONG WITH THE SYSTEM,

HE PUT A LOT OF PRESSURE ON BOEING.

Lauda: I WAS AFTER BOEING DAY AND NIGHT

SO THAT THE PEOPLE UNDERSTAND THAT WE'RE WORKING ON IT,

THAT WE'LL HOPEFULLY FIND THE CAUSE

AND MAKE SURE IT WILL NEVER, EVER HAPPEN AGAIN,

BECAUSE THIS IS THE ANSWERS THESE FAMILIES NEEDED.

Narrator: WITH PRESSURE MOUNTING ON BOEING,

BOB MACINTOSH RETURNS TO THE CRASH SITE

IN SEARCH OF ANY EVIDENCE

THAT CAN HELP EXPLAIN WHAT WENT WRONG.

Macintosh: LET'S GET TO IT.

Narrator: HE THINKS THERE MIGHT BE ANOTHER WAY

TO GET HIS HANDS ON SOME OF THE DATA

THAT HE COULDN'T GET FROM THE BADLY BURNED FDR.

Macintosh: WE SCAMPERED OUT THERE

WITH A COUPLE OF RUDIMENTARY TOOLS LIKE PLIERS,

A SCREWDRIVER AND WHATNOT,

AND GOT OUT THERE AS FAST AS WE COULD.

Narrator: THE ENGINES OF A 767 ARE EQUIPPED

WITH AN ELECTRONIC ENGINE CONTROL UNIT, OR EEC.

MACINTOSH HOPES THE UNIT'S INTERNAL MEMORY

WILL PRESERVE A RECORD

OF HOW THE PLANE'S ENGINES WERE OPERATING JUST BEFORE THE CRASH.

Macintosh: AND, SURE ENOUGH, THERE WAS THE EEC,

THE ENGINE ELECTRONIC CONTROL, FULLY AVAILABLE TO US.

WE WERE EXTREMELY INTERESTED IN GETTING THAT INFORMATION

OUT OF THE JUNGLE AND INTO A PROPER READOUT FACILITY.

YOU GOT A BAG THERE?

Narrator: THE CRITICAL QUESTION NOW--

CAN THE ENGINE DATA REVEAL WHY THE LAUDA PILOTS

SUDDENLY LOST CONTROL OF THEIR PLANE?

INVESTIGATORS MAY BE A STEP CLOSER TO UNDERSTANDING

WHAT BROUGHT DOWN LAUDA FLIGHT 4.

THEY HAVE CRITICAL DATA

FROM THE PLANE'S ELECTRONIC ENGINE CONTROL UNIT.

Macintosh: WE NOW HAD AIRSPEED AND WE HAD ALTITUDE INFORMATION,

AND ALTHOUGH WE DIDN'T HAVE EXACT TIMINGS

ON THOSE PIECES OF INFORMATION,

IT LED US TO THE UNDERSTANDING OF THE LOSS OF CONTROL.

Woman: WOW. THAT'LL SURE GET YOUR FULL ATTENTION.

Narrator: THE DATA GIVES MACINTOSH A CLEARER PICTURE

OF WHY THE PLANE BROKE UP IN FLIGHT.

OPERATING AT NEARLY FULL POWER,

THE LEFT ENGINE SUDDENLY GOES INTO REVERSE.

Thurner: REVERSER'S DEPLOYED.

Welch: OH, CHRIST!

Macintosh: FOLLOWING THE EXCLAMATION FROM THE CO-PILOT,

"AH, THRUST REVERSE,"

THERE WAS A LOT OF ACTION GOING ON IN THE COCKPIT.

Narrator: CAPTAIN WELCH IMMEDIATELY TRIES TO CORRECT THE PROBLEM.

Welch: HERE.

WAIT A MINUTE.

Macintosh: THE ENGINES HAD BEEN DRAWN TO IDLE...

AND EVEN THE FUEL ON THE LEFT ENGINE

HAD BEEN SHUT DOWN.

Narrator: YET JUST SECONDS LATER,

THE BOEING 767 IS PLUNGING TO EARTH

AT ALMOST THE SPEED OF SOUND.

Woman: NO MYSTERY WHY THAT PLANE BROKE APART.

Narrator: THE SHEER FORCE OF THE VIOLENT DESCENT

TEARS THE AIRCRAFT TO PIECES.

Darcy: IF YOU ARE IN A PROLONGED DIVE

AND THAT SPEED INCREASES

BEYOND WHAT THE AIRPLANE WAS DESIGNED FOR,

THE AERODYNAMIC LOADS CAN BE MORE THAN THE AIRPLANE CAN TAKE.

Narrator: THE REVELATION EXPLAINS THE WITNESS REPORTS.

THE EXPLOSION THEY HEARD WAS THE PLANE BREAKING APART.

FUEL LEAKING FROM THE RUPTURED TANKS

IGNITED AND CAUSED THE FIRE.

NIKI LAUDA TRAVELS TO BOEING HEADQUARTERS IN SEATTLE.

HE'S DETERMINED TO FIGURE OUT

WHY A FAILURE THAT'S NOT SUPPOSED TO BE DANGEROUS

KILLED 223 PEOPLE FLYING ON HIS AIRLINE.

Lauda: I KNOW WHAT IT SAYS,

BUT THAT'S NOT WHAT HAPPENED IN THAILAND.

AND I SAID TO BOEING, LISTEN, GUYS.

IT'S MY NAME, MY AIRPLANE, MY CRASH,

AND BOEING UNDERSTOOD MY PROBLEM, OR THEIR PROBLEM,

AND WE KEPT ON WORKING TOGETHER.

Narrator: LAUDA'S DETERMINATION ECHOES THE TENACITY

HE SHOWED IN FORMULA ONE,

ALWAYS PUSHING HIS MECHANICS TO GAIN A SLIGHT ADVANTAGE.

Lauda: BASICALLY, I UNDERSTOOD

THAT THE MORE YOU WORK WITH YOUR CAR,

YOUR ENGINEERS AND YOUR MECHANICS,

TO MAKE THE CAR ON THE DAY ADJUSTED IN THE RIGHT WAY

THAT IT CAN GO QUICKER,

THIS WAS THE SECRET.

OK. LET'S TRY IT IN A SIMULATOR.

Volker: IT WAS IMPORTANT TO PUSH BOEING

BECAUSE THEY WERE THE ONLY KEY OF THE WHOLE,

OF THE WHOLE MATTER.

Narrator: LAUDA RECREATES THE FLIGHT IN THE BOEING SIMULATOR.

Lauda: OK. LET'S BEGIN.

Narrator: HE WANTS TO KNOW WHY HIS PILOTS COULDN'T DO

WHAT THE PLANE WAS CERTIFIED TO DO--

RECOVER FROM A DEPLOYED REVERSER.

Lauda: APPROACHING 24,000 FEET.

AIRSPEED 320 KNOTS.

ANOTHER HUNDRED FEET.

IT WAS INCREDIBLE

BECAUSE THE AIRPLANE JUST TURNED AROUND

AND YOU COULDN'T DO ANYTHING.

LOOKING AT EVERY SEQUENCE SLOWLY AND DOING IT AGAIN AND AGAIN,

YOU REALIZE NOTHING THEY COULD HAVE DONE.

Narrator: LAUDA'S TESTS AT BOEING

SHOW THAT THE PILOTS OF FLIGHT 4

DIDN'T HAVE ENOUGH TIME TO EXECUTE THE COMMANDS

NEEDED TO SAVE THE PLANE.

Macintosh: HARD RIGHT, AUTO THROTTLE OFF,

THRUST LEVER TO IDLE, LEFT ENGINE SHUTDOWN.

THERE WOULD BE A 4 to 6-SECOND WINDOW

WHERE A FLIGHT CREW MEMBER WOULD HAVE TO INITIATE

CONTRARY FLIGHT CONTROLS TO THIS CONDITION

IN ORDER TO RECOVER IN A SAFE MANNER.

AND BEFORE YOU DO ANY OF THAT,

FIGURE OUT WHAT THE HELL'S HAPPENING TO YOUR PLANE.

ALL IN SIX SECONDS?

GOOD LUCK.

IT WAS JUST TOO LATE.

THE AIRCRAFT WAS GONNA ASSUME

A VERY NOSE LOW, HIGH SPEED ATTITUDE.

Thurner: REVERSER'S DEPLOYED.

Welch: OH, CHRIST!

Narrator: IT'S CLEAR.

THE ACCIDENTAL DEPLOYMENT OF A THRUST REVERSER

IS MUCH MORE THAN A HARMLESS MALFUNCTION.

IT CAN BE FATAL.

Macintosh: IT WAS EVIDENT TO THE BOEING COMPANY

AND TO THE FAA CERTIFICATION AUTHORITIES

AND TO THE OPERATORS OF BOEING 767s AROUND THE WORLD

THAT THIS WAS GONNA BE A MAJOR, MAJOR ISSUE.

Narrator: THE FINDING HAS STAGGERING IMPLICATIONS.

INVESTIGATORS MUST FIGURE OUT

WHY THE REVERSER DEPLOYED IN THE FIRST PLACE.

ACCORDING TO THE AIRCRAFT'S DESIGNERS,

IT JUST SHOULDN'T HAPPEN.

Lauda: IT WAS PRETTY OBVIOUS AFTER A WHILE TO UNDERSTAND

THAT THE THRUST REVERSE MADE THE AIRPLANE CRASH,

SO THIS WAS CLEAR,

BUT YOU STILL NEED TO KNOW THE EXACT CAUSE,

AND THEN ESPECIALLY FOR THE FUTURE

WHAT ARE YOU GONNA DO TO MAKE AIRPLANES SAFER.

Macintosh: THE REVERSER DEPLOYED AND THOSE GUYS COULDN'T RECOVER.

LET'S FIGURE OUT WHY THAT HAPPENED.

Darcy: FOR THE REVERSER TO DEPLOY,

IT REQUIRES YOU HAVE

TWO SEPARATE AND INDEPENDENT VALVES OPEN.

Narrator: THE FIRST VALVE IS THE ISOLATION VALVE

THAT CONTROLS THE FLOW OF HYDRAULIC FLUID.

BUT THE REVERSER WON'T DEPLOY UNTIL A SECOND VALVE,

THE DIRECTIONAL CONTROL VALVE, MOVES FROM STOW TO DEPLOY.

INVESTIGATORS WONDER IF THAT CRUCIAL SECOND VALVE

SOMEHOW ENDED UP IN THE WRONG POSITION.

Macintosh: TO THE INVESTIGATION TEAM,

THE DIRECTIONAL CONTROL VALVE WAS A VERY CRITICAL PORTION

OF THE EVIDENCE THAT WE NEEDED FOR ANALYSIS.

Narrator: BUT THE CRUCIAL COMPONENT IS NOWHERE TO BE FOUND.

IT'S LIKELY THAT LOOTERS AT THE CRASH SITE

HAVE STOLEN THE VALUABLE PART.

Darcy: THE DIRECTIONAL CONTROL VALVE WAS GOLD-COLORED.

WE SPECULATE THAT SOMEONE THOUGHT IT HAD SOME VALUE

JUST FOR BEING SCRAPPED OR SOLD.

Macintosh: WE NEED TO FIND THE DIRECTIONAL CONTROL VALVE.

THAT'S NOT OUR TOP PRIORITY.

THAT'S OUR ONLY PRIORITY.

Narrator: THEY OFFER A CASH REWARD TO GET IT BACK.

Macintosh: WE REALLY WANTED TO KNOW

WHAT HAD DRIVEN THOSE THRUST REVERSERS OPEN,

AND THAT WAS THE PIECE OF ELECTRONIC/HYDRAULIC EQUIPMENT

THAT WOULD GIVE US THAT CLUE.

Narrator: NINE MONTHS AFTER THE ACCIDENT, THE REWARD PAYS OFF.

INVESTIGATORS FINALLY GET THEIR HANDS

ON THE PIECE THEY NEED MOST, THE DIRECTIONAL CONTROL VALVE.

Macintosh: SOMEONE SHOWED UP TO CLAIM A REWARD.

THEY PRESENTED THE PIECE OF EVIDENCE

AND IT MADE ITS WAY RELATIVELY QUICKLY

TO THE ENGINEERING ASSESSMENT LAB OUT IN SEATTLE, WASHINGTON.

Narrator: INVESTIGATORS ARE EAGER TO KNOW

WHAT POSITION THE VALVE WAS IN AT THE TIME OF THE ACCIDENT.

Darcy: IN ONE POSITION IT TELLS THE THRUST REVERSER

TO STOW AND REMAIN STOWED,

AND IN ANOTHER POSITION IT TELLS THE THRUST REVERSER TO DEPLOY.

Narrator: SEVERAL SCREWS ARE LOOSE AND SOME PARTS ARE MISPLACED.

Darcy: AS SOON AS YOU SEE THAT, YOU KNOW THAT YOU MAY NOT HAVE

ALL THE EVIDENCE YOU REALLY NEED.

Narrator: THEY FIND SOIL INSIDE THE COMPONENT--

A CLEAR SIGN THAT IT'S BEEN TAKEN APART

AND THEN CARELESSLY REASSEMBLED.

IT'S A BIG BLOW TO THE INVESTIGATION.

Darcy: IT WAS DISAPPOINTING THAT WHEN WE RECEIVED THE VALVE

THAT WE KNEW THAT IT HAD BEEN TAMPERED WITH.

Narrator: ENGINEERS WILL NEED TO FIND ANOTHER WAY

TO UNCOVER WHAT WENT WRONG ON LAUDA FLIGHT 4.

NIKI LAUDA CONTINUES HIS QUEST TO UNDERSTAND

WHY THE PILOTS OF LAUDA FLIGHT 4

COULDN'T SAVE THEIR PLANE.

HE REVIEWS BOEING TEST DATA THAT SHOWS A 767

SHOULD LOSE ONLY 10% OF ITS LIFT

IF A THRUST REVERSER DEPLOYS ACCIDENTALLY.

Lauda: TRUST ME.

IF THEY HAD LOST ONLY 10% OF THEIR LIFT,

THEY WOULD STILL BE HERE.

Narrator: LAUDA COMPARES THE FLIGHT CONDITIONS

USED DURING THE BOEING TEST

TO THE CONDITIONS HIS PILOTS FACED

AT THE TIME OF THE ACCIDENT.

HE MAKES A STUNNING DISCOVERY.

THE BOEING TEST FLIGHTS WERE AT A RELATIVELY LOW ALTITUDE--

JUST 10,000 FEET.

Lauda: NOBODY TESTED IT HIGH UP.

THERE'S A HELL OF A DIFFERENCE

IF YOU'RE FLYING 10,000 FEET OR AT 28,000 FEET,

AND THAT'S EXACTLY WHAT THAT CERTIFICATION MISINTERPRETED.

Narrator: THE LAUDA 767 WAS FLYING TWICE AS FAST

AND AT MORE THAN TWICE THE ALTITUDE

OF THE BOEING TEST PLANE--

A HEIGHT WHERE THE THIN AIR

MAKES IT MUCH MORE DIFFICULT TO MAINTAIN LIFT.

Macintosh: WE STARTED TO HOME IN ON THE ISSUE

OF A POSSIBLE LOSS OF LIFT FROM THE AFFECTED WING.

Narrator: BOEING ENGINEERS CAN IMAGINE ONLY ONE SCENARIO

THAT MIGHT MAKE A REVERSER DEPLOY UNEXPECTEDLY IN MIDAIR.

THE THEORY CALLS FOR THE ACCIDENTAL ACTIVATION

OF TWO KEY VALVES AT THE SAME TIME.

Darcy: YOU HAVE TO HAVE BOTH THE ISOLATION VALVE OPEN

AND THE DIRECTIONAL CONTROL VALVE AT THE ENGINE

OPEN TO THE DEPLOYED POSITION.

Narrator: THE PROBLEM IS, THEY CAN'T FIGURE OUT

HOW TO MAKE THAT HAPPEN.

AND UNTIL THEY DO,

IT WILL BE IMPOSSIBLE TO PREVENT IT FROM HAPPENING AGAIN.

Darcy: THERE'S A NUMBER OF COMBINATIONS OF THINGS

THAT YOU NEEDED TO LOOK AT,

LIKE A BAD RELAY AND A CUT O-RING.

OR A SHORTED WIRE, SAY, AND DEBRIS IN A VALVE

THAT WOULD, COMBINED, CAUSE THE UNWANTED DEPLOYMENT.

Narrator: THE ENGINEERS CAN FIND WAYS

TO ACTIVATE ONE VALVE OR THE OTHER,

BUT IT SEEMS IMPOSSIBLE TO TRIGGER BOTH AT THE SAME TIME.

Darcy: IT'S ALWAYS FRUSTRATING

WHEN YOU SPEND A TREMENDOUS AMOUNT OF TIME AND EFFORT

AND YOU WANT TO FIND OUT WHAT HAPPENED,

AND YOU JUST CAN'T FIND THE SMOKING GUN.

Narrator: A CATASTROPHIC ACCIDENT CAN DESTROY SMALL AIRLINES.

NIKI LAUDA IS DETERMINED NOT TO LET THAT HAPPEN.

THE PLANE HE LOST REPRESENTS A QUARTER OF HIS FLEET.

HE NEEDS ANOTHER PLANE IN THE AIR TO KEEP HIS BUSINESS.

Volker: ONE OF HIS MAJOR ASSETS WAS HIS COMPETITION SPIRIT,

AND HE WOULDN'T ACCEPT NO AND THAT'S, THAT'S NOT POSSIBLE.

Narrator: HE FINDS A JETLINER IN FRANCE THAT NO ONE IS USING.

WITHIN WEEKS, IT'S BEEN ADDED TO LAUDA'S FLEET.

Lauda: I PICKED UP A 767 IN PARIS,

FLEW IT TO VIENNA TO REPLACE OUR CRASHED AIRPLANE

TO KEEP ON FLYING OUR SCHEDULES.

TO RUN AN AIRLINE AS A BUSINESS IS HARDER THAN TO WIN

THREE WORLD CHAMPIONSHIPS IN FORMULA ONE,

I CAN TELL YOU THAT, BECAUSE THE BUSINESS CHALLENGES

IN AN AIRLINE ARE ENORMOUS.

Narrator: THE TESTS AT BOEING FINALLY PAY OFF,

AND THE ENGINEERS MAKE A MAJOR BREAKTHROUGH.

THEY'RE NOW ABLE TO TRIGGER THE DOUBLE FAILURE

NEEDED TO ACCIDENTALLY DEPLOY A REVERSER.

Macintosh: WE COULD GET THAT SYSTEM TO ACTIVATE

BY INTRODUCING A SHORT IN A... A DIRECT SHORT IN A SYSTEM.

Narrator: THE WIRES FOR BOTH VALVES WERE BUNDLED IN THE SAME HARNESS.

A FAULT ACROSS SEVERAL WIRES IN THAT HARNESS

COULD HAVE TRIGGERED THE SIMULTANEOUS SHORT CIRCUITS.

BUT BECAUSE THE WIRES WERE SO BADLY BURNED IN THE CRASH,

THERE'S NO WAY TO DETERMINE WHAT CAUSED THE SHORT IN THE BUNDLE.

Thurner: SCHEISSE.

Welch: YEAH, THAT KEEPS, UH, IT'S COME ON.

Narrator: THE THEORY ACCOUNTS FOR THE INTERMITTENT WARNING

IN THE COCKPIT.

Thurner: SHOULD I ASK THE GROUND STAFF?

Welch: NO. IT'S PROBABLY MOISTURE OR SOMETHING.

Narrator: IT ALSO EXPLAINS THE DEPLOYMENT OF THE THRUST REVERSER.

Welch: UGH! OH!

Macintosh: TWO SHORTS IN TWO VALVES AT EXACTLY THE SAME TIME?

WHAT ARE THE ODDS?

Thurner: REVERSER'S DEPLOYED.

Welch: OH, CHRIST!

Lauda: I WAS UPSET THAT THE AIRPLANE DID SOMETHING

WHERE A HUMAN BEING COULDN'T REACT ANYMORE.

Darcy: WHAT WE HAD LEARNED WAS THAT THE INFLIGHT DEPLOYMENT

WAS SOMETHING THAT COULD HAPPEN WHEN WE NEVER EXPECTED IT WOULD.

Macintosh: TO THE AVIATION INDUSTRY

IT WAS A BIT OF A "COME TO JESUS" MOMENT.

Darcy: WE COULDN'T ALLOW AIRPLANES TO BE OUT THERE FLYING

WHERE THAT COULD HAPPEN.

Narrator: ONE OF THE MOST SHOCKING LESSONS LEARNED

FROM THE LAUDA ACCIDENT

IS HOW SERIOUS A REVERSER DEPLOYMENT CAN BE

AT HIGH SPEED AND HIGH ALTITUDE.

Macintosh: THERE WERE OTHER AIRLINES THAT JOINED IN THE QUESTIONING

OF HOW COULD THIS POSSIBLY AFFECT THE FLIGHT PATH

TO THE POINT WHERE YOU LOSE CONTROL?

Narrator: THE ANSWER TO THAT QUESTION GOES BACK TO THE 1970s.

TO INCREASE FUEL EFFICIENCY,

DESIGNERS MOVE TOWARD SLEEKER AERODYNAMIC DESIGNS.

THEY BEGIN MOUNTING ENGINES

CLOSER TO THE CRUCIAL LEADING EDGE OF THE WING.

Darcy: IN THE CASE OF THE 767,

THEY'RE UP WAY CLOSER TO THE WING,

AND THEIR RELATIVE SIZE TO THE WING IS MUCH BIGGER,

SO THE EFFECT OF REVERSE THRUST ON THE 767

WOULD BE WAY GREATER THAN IT WOULD BE ON A 747.

Narrator: THE DESIGN OF THE THRUST REVERSERS ALSO CHANGES.

EARLIER MODELS USED BUCKETS AT THE REAR OF THE ENGINE

THAT REDIRECTED AIR NEAR THE BACK OF THE WING.

NEWER DESIGNS REDIRECT AIR CLOSER TO THE FRONT OF THE WING.

TO FIND OUT HOW THE CHANGES MIGHT AFFECT AERODYNAMIC LIFT,

NASA RUNS A SERIES OF SPECIAL TEST FLIGHTS.

Pilot: OK. RECORDERS ON.

Narrator: FLYING A DC-8, NASA PILOTS

MATCH THE LAUDA FLIGHT'S HIGH SPEED AND ALTITUDE.

Pilot: OK. YOU SHOULD BE DEPLOYING THOSE.

Narrator: THEN THEY DEPLOY A REVERSER.

Pilot: THERE THEY GO.

Narrator: THE RESULTS ARE DRAMATIC.

Pilot: PRETTY, UH, STRONG...

Macintosh: THERE WAS ABOUT A 25% LOSS OF LIFT

OVER THE AFFECTED WING.

THAT LOSS OF LIFT WOULD RESULT IN A ROLL RATE

THAT WOULD BE EXTREMELY DIFFICULT

FOR A FLIGHT CREW TO COMBAT.

Pilot: PASSING BETWEEN...

Narrator: DEPLOYING ONE REVERSER

WHILE KEEPING THREE ENGINES OPERATING NORMALLY

SENDS THE DC-8 INTO A TERRIFYING DIVE,

FALLING AT ALMOST 9,000 FEET PER MINUTE.

Pilot: OK.

Narrator: THE EXPERIMENT REVEALS WHY FLIGHT 4 LOST SO MUCH LIFT.

UNLIKE PREVIOUS DESIGNS, MODERN REVERSERS

DISRUPT THE SMOOTH FLOW OF AIR OVER THE WING,

WHICH DECREASES LIFT.

THE STUNNING RESULTS CHANGE COMMERCIAL AVIATION WORLDWIDE.

INFLIGHT DEPLOYMENT OF A THRUST REVERSER

IS NO LONGER CONSIDERED CONTROLLABLE...

AND A SERIES OF MECHANICAL LOCKS NOW ENSURE

THAT EVEN IF BOTH VALVES GET ENERGIZED IN FLIGHT,

THE REVERSERS CAN'T DEPLOY.

Macintosh: THERE WERE SOME MAJOR EFFORTS MADE WORLDWIDE

TO MAKE SURE THAT THE IMPROVEMENTS

OF A SYNC LOCK SYSTEM WERE INSTALLED

IN EVERY OPERATIONAL AIRPLANE

AND EVERY AIRPLANE THAT WAS MANUFACTURED THEREAFTER.

Narrator: FOR NIKI LAUDA, IT IS TOTAL VINDICATION.

Lauda: I WAS AFFECTED MYSELF.

I WAS AFFECTED AS A PILOT,

SO THIS DROVE ME ALL THE WAY TO THE EXTREME

TO FIND OUT AS QUICK AS POSSIBLE WHAT HAPPENED.

Narrator: THE SPORTS HERO HAS GONE FROM WINNING CHAMPIONSHIPS

TO PROTECTING THE LIVES OF PASSENGERS.

Volker: NIKI WANTED FOR HIS OWN SAKE TO HAVE THE MATTER CLEARED,

AND OF COURSE FOR THE SAKE OF ANY PASSENGER

WHO STEPPED INTO A 767.

Narrator: LAUDA AIR CONTINUED TO OPERATE

FOR NINE MORE YEARS AFTER THE ACCIDENT.

IN 2000, IT WAS FOLDED INTO AUSTRIAN AIRLINES.

Lauda: FOR ME, THE WORST THING IN LIFE IS GRAY AREAS.

I HATE GRAY AREAS AND, UM,

AND A LOT OF AIRPLANE CRASHES HAVE BEEN IN THE PAST

WHERE YOU REALLY DO NOT KNOW EXACTLY WHAT HAPPENED.

AND IN THIS CRASH HERE,

THANK GOD IT WAS CLEAR WHAT WAS THE CAUSE,

AND IT WAS FIXED FOR ALL AIRPLANES WORLDWIDE,

SO I THINK THIS IS THE ONLY GOOD THING

OUT OF THIS TERRIBLE CRASH.