Original subtitles

We've lost engine number two.

High above the Mediterranean, two pilots

struggle with a stalled engine.

struggle with a stalled engine.

Engine relight.

- Negative. - Stop.

Stop.

Engine one has flamed out.

45 miles from land, the pilots

45 miles from land, the pilots

make a difficult decision.

Prepare to ditch.

Prepare to ditch.

Oh my God, be merciful.

Passengers are forced to make life or death

decisions on their own.

decisions on their own.

Do not inflate your vest!

The accident will tear families apart...

The accident will tear families apart...

...set in motion a massive rescue effort at sea,

and trigger a multinational investigation

and trigger a multinational investigation

to discover why both engines on one of the world's most popular

to discover why both engines on one of the world's most popular

planes stopped in midflight.

planes stopped in midflight.

Ladies and gentlemen, we are starting our approach.

We lost both engines.

August 6, 2005.

August 6, 2005.

Bari, Italy, an ancient port town on the Adriatic sea

where the past meets the present.

where the past meets the present.

Just north of this historic city, Bari International

Just north of this historic city, Bari International

Airport serves 10 major Airlines and more than 1.5

million passengers each year.

One of those carriers is Tunisia's Tuninter Airlines.

One of those carriers is Tunisia's Tuninter Airlines.

Captain Chafik Gharbi is a pilot with Tuninter.

Today, he's in command of flight 1153.

Today, he's in command of flight 1153.

The 45-year-old Tunisian is a military-trained pilot

The 45-year-old Tunisian is a military-trained pilot

with a flawless flight record.

Gharbi's co-pilot is 28-year-old Ali Kebaier.

Gharbi's co-pilot is 28-year-old Ali Kebaier.

How much fuel are you adding?

400 kilograms.

2,700 total?

2,700 total?

Yes.

Captain Gharbi and his co-pilot

Captain Gharbi and his co-pilot

flew from Tunis to Bari this morning to collect

34 Italian passengers.

Now they're going to fly them to Djerba,

Now they're going to fly them to Djerba,

a tunisian resort island.

Among the passengers is 31-year-old police

officer, Luca Squicciarini.

His girlfriend, Paola, is traveling with him.

His girlfriend, Paola, is traveling with him.

Our first choice wasn't Djerba, it was Cape Verde.

The thing with Cape Verde is that it was a period

of terrorist activities.

The flight would have left from either Rome or Milan.

The flight would have left from either Rome or Milan.

Since they are two large airports,

Paola was afraid that there would be an attack,

so we chose not to go to Cape Verde.

so we chose not to go to Cape Verde.

It was my first trip with Paola.

It was my first trip with Paola.

We met the previous winter.

We had plans to marry the following year.

To tighten your belt,

pull on the loose end of the strap.

To release your seatbelt, lift the upper portion

of the buckle.

Ladies and gentlemen, your life vests

are located beneath your seats.

To inflate the vest, pull firmly on the red cord

To inflate the vest, pull firmly on the red cord

only when you're leaving the aircraft.

If you need to refill the vest, blow into the mouthpiece.

TSLBB flight 1153, permission for takeoff granted.

TSLBB flight 1153, permission for takeoff granted.

Roger that.

Cleared for takeoff.

Final prep for departure.

Final prep for departure.

The crew is flying a French-made ATR 72.

The crew is flying a French-made ATR 72.

The small turboprop is perfect for short flights.

It doesn't need a lot of maintenance

It doesn't need a lot of maintenance

or guzzle a lot of fuel.

Just after 2:30 in the afternoon, the plane takes off.

Just after 2:30 in the afternoon, the plane takes off.

49 minutes after takeoff, flight 1153 is 400 miles away

49 minutes after takeoff, flight 1153 is 400 miles away

from its destination, Djerba.

So we started chatting with other passengers.

We were all excited.

We talked about the vacation.

We talked about the vacation.

Then 75 miles from the nearest land

Then 75 miles from the nearest land

and 23,000 feet above the sea, the plane's right engine stops

and 23,000 feet above the sea, the plane's right engine stops

working.

What?

What?

We've lost engine number two.

Let's get to 17,000 feet.

Let's get to 17,000 feet.

TUI1153 request 170.

TUI1153...

Captain Gharbi begins an emergency descent.

Captain Gharbi begins an emergency descent.

Sending 170.

When you have a single-engine flameout, you would descend

When you have a single-engine flameout, you would descend

down to a lower altitude.

The air is thicker, the propeller is more efficient.

Under current conditions,

the ATR 72 can best fly on one engine

the ATR 72 can best fly on one engine

at an altitude of 17,000 feet.

at an altitude of 17,000 feet.

Power lever flight idle, start button.

The crew struggles to restart the right engine.

The crew struggles to restart the right engine.

Negative.

Fuel supply, check.

Fuel supply, check.

But then, less than two minutes

after the first engine quits...

Stop.

Stop.

Engine number one, it's flamed out.

...both of the plane's engines have stopped.

...both of the plane's engines have stopped.

The engine shut off.

Our first thought was of a terrorist attack

Our first thought was of a terrorist attack

since there were so many at the time.

We tried to figure out what was happening,

so we looked towards the cockpit to see if someone was

so we looked towards the cockpit to see if someone was

trying to sabotage the plane.

The plane is now falling to the sea

The plane is now falling to the sea

at 800 feet per minute.

Mayday.

Mayday.

Mayday.

TUI1153.

TUI1153.

We have lost both engines.

Request immediate landing at Palermo.

The crew still hopes to reach an airport,

The crew still hopes to reach an airport,

but they have 70 miles of ocean to cross

before they're over land.

before they're over land.

Crews are trained for almost anything.

There's a checklist for them to follow

to solve most problems, including what

to solve most problems, including what

to do when both engines die.

...checklist.

Fuel supply, check.

Fuel supply, check.

The pilots don't know why their engines have stopped.

The only clue they're getting is a low fuel feed warning.

The only clue they're getting is a low fuel feed warning.

A low pressure warning light tells

a pilot that there's low fuel pressure going to the engine.

a pilot that there's low fuel pressure going to the engine.

Now that could be a mechanical problem or that could

be a contamination problem.

be a contamination problem.

The crew follows the steps

laid out by the manufacturer to relight their dead engines.

laid out by the manufacturer to relight their dead engines.

Fuel supply, check.

Power lever flight idle, start button.

Engine relight, negative.

Get Choukri.

The captain asks the cabin crew

to bring the onboard engineer, Choukri Harbaoui,

to bring the onboard engineer, Choukri Harbaoui,

to the cockpit.

Palermo approach.

This is TUI1153 We have lost both engines.

This is TUI1153 We have lost both engines.

Request immediate landing.

The closest airport is in Palermo on

the Italian island of Sicily.

TUI Palermo.

TUI Palermo.

Affirmative, you are clear for landing.

Palermo approach, what is our distance to the airport?

Palermo approach, what is our distance to the airport?

Your distance to Palermo is now 48 nautical miles.

Your distance to Palermo is now 48 nautical miles.

An ATR 72 will fall from the sky

at a predictable rate, one foot down for every 16 feet forward.

at a predictable rate, one foot down for every 16 feet forward.

If they can't restart their engines soon,

they'll be forced to ditch in the sea.

they'll be forced to ditch in the sea.

Ditching at sea is a very difficult

decision to make because it's the hardest thing to do.

You have swells, waves, wind.

You have swells, waves, wind.

Is anybody going to see you?

How long can the plane float for?

How long can the plane float for?

Landing a passenger plane on water

is extremely dangerous.

is extremely dangerous.

In 1996, an Ethiopian Airlines pilot

was forced to bring his 767 down on the Indian Ocean.

was forced to bring his 767 down on the Indian Ocean.

The ditching was recorded by a tourist on a nearby beach.

The ditching was recorded by a tourist on a nearby beach.

50 people survived, but 125 people died.

50 people survived, but 125 people died.

The crew of this small plane doesn't usually

The crew of this small plane doesn't usually

include an engineer.

When there is one on board, he usually travels in the cabin.

When there is one on board, he usually travels in the cabin.

I remembered this person looked at the stewardess

and shook his head, as if saying no after the second engine

and shook his head, as if saying no after the second engine

had shut off.

That gesture showed there was nothing left to do.

That gesture showed there was nothing left to do.

The crew of flight 1153 has tried all it can.

The crew of flight 1153 has tried all it can.

They're running out of time and options.

Flight engineer, Choukri Harbaoui,

has joined in the struggle to get

flight 1153's engine started.

flight 1153's engine started.

You've run the checklist?

Yes.

Yes.

The captain hopes the engineer

will know something that isn't covered by the checklist.

Attempt to restart the engines.

Attempt to restart the engines.

Right engine first.

Fuel supply, check.

Engine two start power button, on.

Engine two start power button, on.

Engine relight, negative.

Palermo approach, TUI1153.

Palermo approach, TUI1153.

Any closer airport where we can land?

Any closer airport where we can land?

Negative, 1153.

Palermo airport is the closest airport to your position.

Palermo airport is the closest airport to your position.

We're not going to make it.

Prepare to ditch.

Oh my God, be merciful.

No one said anything.

No one said anything.

I noticed something wasn't right because the two

engines shut off.

More than once, I tried to get the stewardess's attention,

More than once, I tried to get the stewardess's attention,

asking what I should do.

If I had to put on the life jacket, if I had to stand,

If I had to put on the life jacket, if I had to stand,

if I should take off my shoes.

I got no answer.

She was in shock and started to cry.

She was in shock and started to cry.

The senior flight attendant

does give passengers direction.

does give passengers direction.

The captain has decided to land the plane at sea.

The captain has decided to land the plane at sea.

I'll let you imagine the panic on board.

I'll let you imagine the panic on board.

People were screaming and crying.

Please, stay calm and follow your crew's instructions.

Please, stay calm and follow your crew's instructions.

There were people in the front seats

that had a baby girl.

that had a baby girl.

She had been playing and was so excited.

To now see the panic in her mother's face

made me feel so sad.

made me feel so sad.

TUI1153, what is your fuel load?

TUI1153, what is your fuel load?

Cockpit fuel quantity 1,800 kilograms.

Cockpit fuel quantity 1,800 kilograms.

Captain Gharbi's fuel gauge shows that he has

plenty of fuel, but for some reason,

neither engine will restart.

neither engine will restart.

Just 10 minutes after the trouble began,

the plane is 7,000 feet above the ocean and falling.

the plane is 7,000 feet above the ocean and falling.

Outside, it's completely silent.

But in the cabin, there's panic.

But in the cabin, there's panic.

Please remain in your seats with your seatbelts fastened.

Please remain in your seats with your seatbelts fastened.

My first instinct

was to undo my seatbelt to prevent getting

trapped when we hit the water.

trapped when we hit the water.

I didn't want to be trapped in my seat

and go down in a horrible way.

Do not inflate your vests

until you've left the plane.

A plane ditching at sea

A plane ditching at sea

will more than likely fill with water.

That's why safety procedures call for passengers

to only inflate their life vests once they've cleared the plane.

to only inflate their life vests once they've cleared the plane.

Otherwise, they could become trapped inside

Otherwise, they could become trapped inside

the flooded fuselage and drown.

The dead engines aren't the only problem confronting the crew.

The dead engines aren't the only problem confronting the crew.

Many of their instruments get their power from the engines.

Many of their instruments get their power from the engines.

Without the engines, some vital gauges are dead.

On a two-engine flameout, you go on your standby instruments,

On a two-engine flameout, you go on your standby instruments,

which is you have an attitude indicator,

you have an altimeter.

you have an altimeter.

Fuel supply, check.

The crew continues to try to restart their engines,

but it's become clear that they've run out of time.

but it's become clear that they've run out of time.

They're not doing anything.

Confirm distance, please.

Your distance is now 20 miles.

Your distance is now 20 miles.

Boats.

I see boats.

I see boats.

Palermo approach.

TUI1153.

We can't make it to the airport.

We can't make it to the airport.

We see two boats on the left side.

We're going there.

We're going there.

If you can, please call.

Captain Gharbi turns his plane toward the boats.

Can you send helicopters or something

Can you send helicopters or something

similar, fast, fast, fast?

Emergency.

All marine units, aircraft in distress

All marine units, aircraft in distress

20 nautical miles off Palermo.

Even before the plane hits the water,

Even before the plane hits the water,

rescuers are on their way.

I had very little information.

We didn't know the nature of the crash

or anything about the plane.

or anything about the plane.

Autopress, dump.

Although it's a rare maneuver,

there is also a checklist for ditching a plane in the water.

there is also a checklist for ditching a plane in the water.

Valve, full close.

Before ditching, the crew

Before ditching, the crew

ensures all landing gear is retracted to help

the plane land more smoothly.

Landing gear lever up.

Landing gear lever up.

When pilots ditch, they want their airplane

as streamlined as possible so that it glides

as streamlined as possible so that it glides

across the water when it hits.

Pilots must not only monitor the systems on the plane,

Pilots must not only monitor the systems on the plane,

they also have to assess conditions at sea.

They don't want to hit a wave head on.

They don't want to hit a wave head on.

If you hit perpendicular to the waves

or swells with the aircraft, it's like hitting concrete.

or swells with the aircraft, it's like hitting concrete.

The plane will break up.

Passengers can see what's coming.

Passengers can see what's coming.

I was hanging on tight to the seat in front of me.

And through the window, I could see the impact was imminent.

And through the window, I could see the impact was imminent.

The crew is 700 feet above the sea.

You're with me, Ali, huh?

You're with me, Ali, huh?

Careful.

Choukri, ready?

Ready.

Here we go.

Here we go.

There is no other God but Allah.

Muhammad is his messenger.

In the name of God merciful, merciful.

In the name of God merciful, merciful.

At a speed of 145 miles an hour,

At a speed of 145 miles an hour,

the plane collides with the sea.

I lost consciousness.

I lost consciousness.

I woke up in the water.

I was two or three meters underwater.

I was two or three meters underwater.

I came up to the surface wearing only my pants.

I had lost my life jacket and clothes on impact.

I had lost my life jacket and clothes on impact.

I got to the surface and grabbed on to a bag.

I got to the surface and grabbed on to a bag.

I was in shock.

I was surrounded by everything.

I was surrounded by everything.

My thoughts were constantly with Paola.

My thoughts were constantly with Paola.

I thought I was going to die because I was spitting blood.

I felt my lungs filling with blood.

I felt my lungs filling with blood.

Captain Gharbi survives

but has been seriously injured.

but has been seriously injured.

Copilot Ali Kebaier has also survived.

But flight engineer Choukri Harbaoui is killed.

But flight engineer Choukri Harbaoui is killed.

No one aboard the nearby boats saw

No one aboard the nearby boats saw

flight 1153 crash into the sea.

The plane is broken into three pieces.

The plane is broken into three pieces.

The tail section and much of the fuselage

sink to the bottom of the sea.

sink to the bottom of the sea.

But the largest section containing the two wings

stays afloat.

stays afloat.

It becomes a makeshift life raft for survivors.

But not all of the passengers have survived.

But not all of the passengers have survived.

Many haven't it made it out of the plane and to the surface.

Helicopter pilot Stefano Burigana is one of the first

Helicopter pilot Stefano Burigana is one of the first

to arrive at the scene.

When we approached the airplane,

we could see the wings floating.

we could see the wings floating.

There were several people in the water

around the aircraft, all floating,

around the aircraft, all floating,

and everybody with their jacket inflated.

and everybody with their jacket inflated.

Burigana spots Luca Squicciarini floating

away from the main wreckage.

away from the main wreckage.

There was one man without his jacket

and he was the farthest from the airplane.

and he was the farthest from the airplane.

I decided to go over him and throw one of our life jackets

I decided to go over him and throw one of our life jackets

to him.

The Coast Guard arrives and begins

pulling survivors from the sea.

Within the hour, the crash site is teeming with rescuers.

Within the hour, the crash site is teeming with rescuers.

They search for survivors from the water and from the air.

They search for survivors from the water and from the air.

23 people are pulled from the Mediterranean sea,

but 16 have died in the crash, including Paola di Cialla.

but 16 have died in the crash, including Paola di Cialla.

It's quite likely that none of those who died ever

It's quite likely that none of those who died ever

had a chance to swim to safety.

Their serious injuries would have

Their serious injuries would have

prevented them from escaping after the plane hit the water.

In this accident, most of the survivors

were seated in the rear of the plane, most

were seated in the rear of the plane, most

of those who died, up front.

Those sections, along with some valuable clues,

Those sections, along with some valuable clues,

are now at the bottom of the sea.

The one section that didn't sink is towed to the port in Palermo

and taken to a nearby hangar.

and taken to a nearby hangar.

A team of agents from Italy's National Flight Safety Agency,

A team of agents from Italy's National Flight Safety Agency,

the ANSV, began looking for leads.

Their job?

Find out why Flight 1153's engines stopped in midflight.

Find out why Flight 1153's engines stopped in midflight.

We need to collect as much as evidence as possible

We need to collect as much as evidence as possible

in order to fulfill two main answers, what happened

in order to fulfill two main answers, what happened

and why had it happened?

They are led by chief ANSV

They are led by chief ANSV

investigator Vincenzo Pennetta.

I arrived in Palermo the day after the accident

I arrived in Palermo the day after the accident

on the seventh, very early in the morning.

A flight test engineer by training, Pennetta

A flight test engineer by training, Pennetta

has led several air crash investigations.

The engines and central fuselage of Tuninter flight 1153

The engines and central fuselage of Tuninter flight 1153

have been recovered.

have been recovered.

The rest of the plane lies somewhere

off the Sicilian coast.

The main challenge of the investigation

The main challenge of the investigation

was the fact that the flight recorder, and the cockpit voice

recorder, and also the front fuselage

recorder, and also the front fuselage

were 1,500 meters under the sea.

While the Italian Navy conducts a deep water search

While the Italian Navy conducts a deep water search

for the rest of the wreck and the crucial black boxes,

Italian investigators are given some assistance by the plane's

Italian investigators are given some assistance by the plane's

European manufacturer.

ATR's Giuseppe Caldarelli is here

ATR's Giuseppe Caldarelli is here

to find out if there's a flaw with the company's plane.

Anytime there is an accident and also when people die,

Anytime there is an accident and also when people die,

for me, is a big accident.

Worldwide, hundreds of ATR 72 seconds

crossed the skies each day.

crossed the skies each day.

Those aircraft have a very sound

structure and robust systems, and are very cost efficient.

structure and robust systems, and are very cost efficient.

Together, Pennetta and Caldarelli

Together, Pennetta and Caldarelli

set to find out why both engines on such an advanced airplane

died in midflight.

died in midflight.

TUI1153.

Before it happens again.

Before it happens again.

Captain Gharbi, how are you?

I'm getting better.

Thank you.

Investigators want to know what

Investigators want to know what

happened in the cockpit of Tuninter flight 1153

when the engines died.

when the engines died.

Without the cockpit voice recorder,

they must rely on the recollections of surviving

passengers and crew members.

passengers and crew members.

The main cause of the double engine failure

could be a lack of fuel.

But according to Captain Chafik Gharbi,

But according to Captain Chafik Gharbi,

lack of fuel was not the problem.

What were your fuel readings?

What were your fuel readings?

The fuel quantity indicator said 1,800 kilograms of fuel.

The fuel quantity indicator said 1,800 kilograms of fuel.

What is your fuel load?

Cockpit fuel quantity 1,800 kilograms.

Cockpit fuel quantity 1,800 kilograms.

Fuel supply, check.

Was there any warning that you were low on fuel?

Was there any warning that you were low on fuel?

There was definitely no low-fuel warning,

just a low feed pressure light.

just a low feed pressure light.

The absence of a low-fuel warning

and the presence of a low feed pressure warning

and the presence of a low feed pressure warning

is a major clue.

This set of alarms usually indicates

This set of alarms usually indicates

that there is a problem in feeding the engine with fuel.

that there is a problem in feeding the engine with fuel.

Since the plane's gauges indicated that there was

fuel on board that did not get to the engines,

ATR's Giuseppe Caldarelli looks for flaws in the fallen plane's

ATR's Giuseppe Caldarelli looks for flaws in the fallen plane's

fuel delivery system.

Four years earlier, an Airbus operated by Air Transat,

Four years earlier, an Airbus operated by Air Transat,

developed a leak in the fuel line that

feeds the plane's right engine.

Over time, the plane leaked all of its fuel

and both engines failed.

and both engines failed.

The pilots were forced to glide their plane

to an emergency landing.

That incident has a lot of similarities

That incident has a lot of similarities

to the Tuninter crash.

His team looks for breaks or blockages in the fuel lines

His team looks for breaks or blockages in the fuel lines

and evidence that the fuel pumps malfunctioned and stopped

fuel flow to the engines.

fuel flow to the engines.

While Caldarelli waits for technicians to complete tests

While Caldarelli waits for technicians to complete tests

on pumps and lines, Pennetta decides

to start a new line of inquiry.

to start a new line of inquiry.

He explores the possibility that the fuel that was on board

He explores the possibility that the fuel that was on board

was somehow contaminated.

Fuel contamination can derive from four

Fuel contamination can derive from four

or five different sources.

Kerosene-based jet fuel is very delicate.

If stored or transferred improperly,

If stored or transferred improperly,

it can be polluted with water, sand,

or fungus, even sticky residue from the hoses

or fungus, even sticky residue from the hoses

of refueling tankers.

Any of these could prevent the fuel from properly igniting

Any of these could prevent the fuel from properly igniting

and could have caused the engines to shut down.

How much fuel are you adding?

400 kilograms.

The plane last took on fuel in Bari.

The plane last took on fuel in Bari.

Samples from the tanker that supplied it

are taken for testing.

Pennetta needs to prove that one of these contaminants

got into flight 1153's fuel, prevented combustion, and

got into flight 1153's fuel, prevented combustion, and

caused both engines to fail.

Sediments can be transferred from the tanker truck

Sediments can be transferred from the tanker truck

to the aircraft.

So the fuel filter can be clogged

So the fuel filter can be clogged

and so the engine can have some problems.

Technicians remove the truck's fuel filters to look

Technicians remove the truck's fuel filters to look

for evidence of contamination.

Hoses and couplings are swabbed for sticky residue or colonies

of microorganisms and submitted for testing at an Italian Air

of microorganisms and submitted for testing at an Italian Air

Force laboratory.

The fuel is filtered for minute particles

suspended in the fluid.

And carefully examined for impurities.

And carefully examined for impurities.

The truck's filters are also inspected for residue

The truck's filters are also inspected for residue

or sediment from the tanks.

Meanwhile, in Palermo, Caldarelli and his technicians

Meanwhile, in Palermo, Caldarelli and his technicians

have completed tests on flight 1153's fuel lines and pumps.

have completed tests on flight 1153's fuel lines and pumps.

The tests are thorough, the results conclusive.

But the fuel feed lines were OK, were no leak.

But the fuel feed lines were OK, were no leak.

If the fuel delivery system was working

and the two pilots remember having ample fuel...

and the two pilots remember having ample fuel...

The fuel quantity indicator said 1,800 kilograms of fuel.

The fuel quantity indicator said 1,800 kilograms of fuel.

...then why had the engines failed?

When test results from the Bari fuel tanker come in,

they, too, are conclusive.

The fuel filters, hose couplings, and tanker

The fuel filters, hose couplings, and tanker

fuel at Bari airport are clean.

So fuel contamination as a source of double engine

So fuel contamination as a source of double engine

flameout was then excluded.

At this point, the investigators

At this point, the investigators

still don't know what caused the downing

of Tuninter flight 1153.

of Tuninter flight 1153.

But something has been eating at Pennetta.

If the plane was filled with fuel,

and since the fuel is stored in the plane's wings,

and since the fuel is stored in the plane's wings,

why did the wing section float?

Floating on the wing indicates that the weight of the wing

Floating on the wing indicates that the weight of the wing

was not so high.

We have been told by ATR that if the amount of fuel that was

We have been told by ATR that if the amount of fuel that was

supposed to be into the wing, around 2,000 kilograms,

were on the fuel tanks, the wings maybe would

were on the fuel tanks, the wings maybe would

not have been able to float.

not have been able to float.

Pennetta suspects the plane didn't have as much fuel

as the pilots thought, but he doesn't know how that could be.

as the pilots thought, but he doesn't know how that could be.

Two weeks into the investigation, Pennetta

Two weeks into the investigation, Pennetta

gets an important lead in the case.

After two weeks of the event, we

received some technical documentation

received some technical documentation

from the aircraft operator.

According to the logs, Captain Gharbi

According to the logs, Captain Gharbi

flew the same aircraft the day before the accident.

After that flight, he reported a problem with his fuel gauge.

After that flight, he reported a problem with his fuel gauge.

When he left the aircraft the day before,

When he left the aircraft the day before,

he reported that the right display fuel

indicator was out of service.

indicator was out of service.

So it needed to be replaced.

The fuel quantity indicator, or FQI,

is a gas gauge that tells pilots how much fuel is left on board.

is a gas gauge that tells pilots how much fuel is left on board.

The lights on the FQI were malfunctioning

and Captain Gharbi made a note of this in the maintenance log.

and Captain Gharbi made a note of this in the maintenance log.

We were able to see that the fuel

quantity indicator was changed the day before the event.

quantity indicator was changed the day before the event.

The maintenance log raises the possibility

The maintenance log raises the possibility

that the FQI that the mechanic installed

was not the right one for the plane.

was not the right one for the plane.

It doesn't seem to have the right model number.

Tuninter flies two models of ATR aircraft, the ATR

Tuninter flies two models of ATR aircraft, the ATR

42 and the larger ATR 72.

The fuel quantity indicators for each plane

The fuel quantity indicators for each plane

look identical except for a different model number

at the top of each unit.

at the top of each unit.

The ATR 72 should have model number 2500.

The ATR 72 should have model number 2500.

But according to the logs, mechanics

installed a unit with the model number 2250 instead.

installed a unit with the model number 2250 instead.

Tuninter's maintenance logs offer a valuable clue.

Tuninter's maintenance logs offer a valuable clue.

But for Pennetta, there's no definitive proof

that the wrong fuel quantity indicator

that the wrong fuel quantity indicator

was installed on the plane.

It could have been a mismatch in that aircraft documentation,

It could have been a mismatch in that aircraft documentation,

so we need to prove that.

There is only one way to know for certain

whether flight 1153 had the right fuel

quantity indicator, go find it at the bottom of the sea.

quantity indicator, go find it at the bottom of the sea.

Not until three weeks after the crash of Flight 1153 do

investigators recover wreckage from the sea.

investigators recover wreckage from the sea.

The data from the plane's black boxes

confirms what the pilots had been saying.

confirms what the pilots had been saying.

There was no warning of low fuel,

so there appeared to be enough fuel to make the flight.

so there appeared to be enough fuel to make the flight.

The black boxes can't solve this mystery.

The black boxes can't solve this mystery.

Investigators hope that the tail and front section can.

Investigators hope that the tail and front section can.

They are hauled aboard a Naval vessel from the sea.

The moment the cockpit is hauled in, Pennetta is there.

The moment the cockpit is hauled in, Pennetta is there.

There's only one thing he wants to see inside.

There's only one thing he wants to see inside.

So when the wreckage was recovered from under the sea

and put on a ship deck, I realized

that as a matter of fact, a fuel quantity indicator

that as a matter of fact, a fuel quantity indicator

for an ATR 42 was installed.

It was like we found the smoking gun.

It was like we found the smoking gun.

The wrong FQI was installed on flight 1153.

The wrong FQI was installed on flight 1153.

Pennetta finally has the break he's been looking for.

The ATR's fuel quantity indicator

collects data from the sensors in the fuel tanks

collects data from the sensors in the fuel tanks

and calculates how much fuel is in the tanks.

But since the fuel tanks on the 42 and the 72

But since the fuel tanks on the 42 and the 72

are different sizes, fuel quantity indicators

are different sizes, fuel quantity indicators

can't be swapped between them.

Technicians conduct refueling tests

Technicians conduct refueling tests

with the wrong FQI installed on an ATR 72

with the wrong FQI installed on an ATR 72

and the results are chilling.

and the results are chilling.

The results show that if you install an FQI type, we'll say

The results show that if you install an FQI type, we'll say

42, on an ATR 72 aircraft, if I have no fuel into the aircraft

42, on an ATR 72 aircraft, if I have no fuel into the aircraft

in the fuel tanks with zero fuel,

the fuel quantity indicator showed me 1,800 kilograms.

the fuel quantity indicator showed me 1,800 kilograms.

Precisely the amount of fuel

that the captain reported having when his engines flamed out.

that the captain reported having when his engines flamed out.

Cockpit fuel quantity eight, 1,800 kilograms.

Cockpit fuel quantity eight, 1,800 kilograms.

Investigators conclude at 23,000 feet above the Mediterranean,

the wrong fuel indicator led the crew

the wrong fuel indicator led the crew

to believe that they had ample fuel when their tanks were

actually empty.

actually empty.

Engine relight, negative.

They're not doing anything.

The engines could not possibly have been restarted.

The engines could not possibly have been restarted.

With hundreds of ATR 42s and ATR 72s still flying,

With hundreds of ATR 42s and ATR 72s still flying,

the implications are stark,

Could there be other planes

Could there be other planes

flying with the wrong gauge?

The first safety recommendation

was to mandate all operators that use ATR 42 and 72 aircraft

was to mandate all operators that use ATR 42 and 72 aircraft

was to mandate all operators that use ATR 42 and 72 aircraft

in their fleet to check whether the right fuel

quantity indicator was installed on the aircraft.

quantity indicator was installed on the aircraft.

Pennetta and Caldarelli have uncovered

the error that caused both of flight 1153's

the error that caused both of flight 1153's

engines to quit in midair.

But the case isn't closed.

Standard flight procedures should

have uncovered the error before takeoff

have uncovered the error before takeoff

and prevented the disaster.

Captain Gharbi's aircraft went in for repairs in Tunisia

Captain Gharbi's aircraft went in for repairs in Tunisia

the night before the crash.

the night before the crash.

The plane's FQI indicated the two tanks together held 790

kilograms of fuel in the tank.

kilograms of fuel in the tank.

After the new fuel quantity indicator was installed,

After the new fuel quantity indicator was installed,

it showed that there was almost four times as much

fuel on board, 3,100 kilograms.

fuel on board, 3,100 kilograms.

The following morning, Captain Gharbi noticed that the fuel

levels had gone up.

levels had gone up.

He assumed that fuel had been added.

But when fuel is added to an aircraft,

But when fuel is added to an aircraft,

a refueling slip must be left in the cockpit.

Where is the refueling slip?

Where is the refueling slip?

The pilot asked to the flight dispatcher,

where was this refueling slip?

where was this refueling slip?

But the flight dispatcher was not able to find

this refueling slip.

I'll get it to you when you get back from Djerba.

I'll get it to you when you get back from Djerba.

Roger that.

There was no refueling slip because the plane

There was no refueling slip because the plane

hadn't been refueled.

In spite of regulations, the captain

left without that vital piece of paper.

left without that vital piece of paper.

There are some standard regulations requiring

the pilot to take off only when he is sure about the quantity

the pilot to take off only when he is sure about the quantity

of fuel.

With the wrong fuel indicator on board

With the wrong fuel indicator on board

and less fuel than he believed, Captain Gharbi

makes it to Bari, Italy, and tops off

makes it to Bari, Italy, and tops off

his plane for the next leg of the trip to Djerba.

his plane for the next leg of the trip to Djerba.

How much fuel are you adding?

How much fuel are you adding?

400 kilograms.

2,700 total?

Yes.

Believing he has 2,700 kilograms of fuel on board,

Believing he has 2,700 kilograms of fuel on board,

Captain Gharbi begins his flight to Djerba.

Captain Gharbi begins his flight to Djerba.

If the correct fuel quantity indicator had been installed,

the captain would have known that he

the captain would have known that he

had only 540 kilograms, not nearly

enough to make the crossing.

enough to make the crossing.

Mayday.

Mayday.

Mayday.

TUI1153 request immediate landing in Palermo.

TUI1153 request immediate landing in Palermo.

We've lost both engines.

Pennetta's investigation comes to a close.

He draws up his final report.

He draws up his final report.

His colleague, Giuseppe Caldarelli, voices a bold view.

Even with no fuel and dead engines,

Flight 1153 could have made it to land.

Flight 1153 could have made it to land.

The aircraft was in a position that

allowed it to reach Palermo.

allowed it to reach Palermo.

TUI1153.

Caldarelli wonders if the pilots

did everything they could have to get

did everything they could have to get

the plane safely to Palermo.

Investigators get some unexpected answers

by having seasoned pilots fly the exact same plane

by having seasoned pilots fly the exact same plane

with the exact same problems.

OK, we are now in big trouble because this second engine

OK, we are now in big trouble because this second engine

has gone off.

Vincenzo Pennetta's investigation into the crash

of Tuninter Flight 1153 has uncovered the events

of Tuninter Flight 1153 has uncovered the events

that led up to the accident.

Now he and Giuseppe Caldarelli need to resolve one question.

Now he and Giuseppe Caldarelli need to resolve one question.

We're not going to make it.

Did mistakes made by the pilots

Did mistakes made by the pilots

cost people their lives?

Caldarelli and his team study the plane's specifications

Caldarelli and his team study the plane's specifications

and draw a surprising conclusion.

and draw a surprising conclusion.

According to manufacturer data, an ATR

is able to glide three miles for every 1,000 feet of descent.

is able to glide three miles for every 1,000 feet of descent.

With the help of a tailwind that day,

With the help of a tailwind that day,

Flight 1153 could have been able to glide 70 miles to Palermo.

Flight 1153 could have been able to glide 70 miles to Palermo.

The crew might have been able to make it.

Landing gear lever up.

Landing gear lever up.

So what had the pilots done wrong?

To answer that question, Pennetta and Caldarelli

recreate flight 1153 in the flight simulator

recreate flight 1153 in the flight simulator

at the ATR facility in France.

Test pilots try to glide an ATR 72 for 70 miles

Test pilots try to glide an ATR 72 for 70 miles

from the altitude at which flight

1153 lost its second engine.

1153 lost its second engine.

The simulation was requested to see

the range of the aircraft starting from the second engine

the range of the aircraft starting from the second engine

out.

Double-engine flameouts, you have to be very aware

Double-engine flameouts, you have to be very aware

of the configuration of the aircraft in order to keep

as much as possible the altitude and distance

as much as possible the altitude and distance

to fly before the crash.

Stop! Stop!

Stop! Stop!

Engine number one has flamed out.

With both engines out, the priority

is to keep the plane gliding as far as necessary.

is to keep the plane gliding as far as necessary.

To do that, pilots can change the angle of their windmilling

To do that, pilots can change the angle of their windmilling

propellers.

You have the maximum glide performance

when you minimize the drag.

when you minimize the drag.

It's very important to think to feather the propeller

in order to reduce the drag.

in order to reduce the drag.

Feathering the props involves changing

their angle against the wind.

their angle against the wind.

The maneuver reduces drag.

When you want to feather the propeller in flight,

When you want to feather the propeller in flight,

you first have to reduce the power

lever to idle and put the condition

lever back to feather position.

lever back to feather position.

The crew did not feather their props

when their engines quit.

when their engines quit.

The windmilling propellers created enormous drag.

If the crew of flight 1153 had feathered their props,

they may have been able to glide further than they did.

By the time Captain Gharbi's second engine flamed out,

By the time Captain Gharbi's second engine flamed out,

he was just below 22,000 feet.

To further reduce drag at that altitude,

To further reduce drag at that altitude,

the plane should be slowed to 158 miles per hour, the ATR

the plane should be slowed to 158 miles per hour, the ATR

72's ideal gliding speed.

Surprisingly, to glide as far as possible,

Surprisingly, to glide as far as possible,

a pilot doesn't want to fly as fast as possible.

The faster a plane flies, the more

The faster a plane flies, the more

the airflow pushes against it, creating resistance.

Every plane has an optimal speed to achieve the furthest glide.

Every plane has an optimal speed to achieve the furthest glide.

The crew of flight 1153 continued flying up to 55 miles

The crew of flight 1153 continued flying up to 55 miles

an hour faster than their optimal gliding speed.

an hour faster than their optimal gliding speed.

That added to the drag on the plane

and reduced the distance they could glide.

and reduced the distance they could glide.

By feathering his props and reducing his speed,

a simulator pilot in France was able to get

a simulator pilot in France was able to get

the plane as far as Palermo.

You're with me, Ali, huh?

You're with me, Ali, huh?

Careful.

Choukri, ready?

Flight 1153 hit the water

Flight 1153 hit the water

26 miles from shore, well short of what the plane

was capable of achieving.

was capable of achieving.

The simulation confirmed that the crew might have been

The simulation confirmed that the crew might have been

able to make it to land and highlights the importance

of proper training to deal with unlikely situations

of proper training to deal with unlikely situations

such as a twin-engine flameout.

In aviation, it's a very rare event.

In aviation, it's a very rare event.

Vincenzo Pennetta's report

urges airlines to train their pilots how

to ditch without engine power.

to ditch without engine power.

Better pilot training is just one

of 17 safety recommendations in the accident report.

of 17 safety recommendations in the accident report.

Perhaps the most important, that ATR redesigned

Perhaps the most important, that ATR redesigned

the fuel quantity indicator.

In order to prevent a fuel quantity

indicator type 42 on a 72 aircraft and vice versa.

indicator type 42 on a 72 aircraft and vice versa.

To prevent mechanics from installing

the incorrect part, Pennetta believes that the only answer

the incorrect part, Pennetta believes that the only answer

is to design the FQIs so that they only fit

is to design the FQIs so that they only fit

on the plane they're meant for.

I'll get to when you get back from Djerba.

I'll get to when you get back from Djerba.

Roger that.

There is no single cause of the accident.

There is no single cause of the accident.

This accident, like many other aircraft accidents,

was determined by a series of actions, a series of events

was determined by a series of actions, a series of events

linked one to each other.

linked one to each other.

This is unheard of.

I would have accepted the engine breaking,

I would have accepted the engine breaking,

or a window shattering.

But to have people die because of a lack of fuel?

But to have people die because of a lack of fuel?

The crash of Flight 1153

The crash of Flight 1153

was caused by a series of grave errors on the ground

and in the air.

and in the air.

In 2012, an Italian court sentenced Captain Gharbi

to 6.5 years in prison for his responsibility in the crash

to 6.5 years in prison for his responsibility in the crash

and subsequent deaths of 16 passengers and crew.

and subsequent deaths of 16 passengers and crew.

Co-captain Kebaier, three Tuninter executives,

and a mechanic received sentences

and a mechanic received sentences

between 5.5 and six years for their liability

in the fatal crash.

in the fatal crash.