Original subtitles

- The Boeing 777.

The biggest selling long-haul aircraft

in the history of aviation.

More than 1,300 of these monsters criss-cross the skies

of the world.

It's one of the best aircraft in history

and its lifespan is exceptional, more than 30 years.

But what's the explanation behind this record longevity?

One of the secrets of its stunning performance is the heavy

checks it undergoes.

Incredible checkups, gigantic technical appraisals

which the aircraft is regularly submitted to.

Overhauls during which the 777 is entirely stripped down.

- So we literally take out all those systems, you go

to the structure, you take a really hard look at what's

going on.

- A giant infrastructure, encompassing this beast

with an unladen weight of 142 tonnes.

- We take apart, we inspect, we put back together.

- Because over the years

an aircraft deteriorates.

We're going to show you how the work routine

attacks the metal.

- You can see here how the glass wool is in shreds,

it's non-existent.

- An aircraft can be struck by lightning.

- Hailstones can also damage the outer shell.

We will lead you to the very heart

of this mythical aircraft.

- I can't tell you precisely how many cables there are

but there are thousands, stretching out

over several hundred kilometers.

- Hundreds of specialists in the work of

totally dismantling the monster.

They know it better than anyone.

You will discover a monumental, surgical operation

carried out by mechanics, technicians, electricians.

Always strictly according to the rules.

High precision work, top of the range services

carried out 24 hours a day, 7 days a week

to meet the deadline.

Will the teams manage to pull off this incredible challenge

in just five weeks.

We're at Orly Airport.

After a nine-hour flight this Boeing 777 lands.

It's immediately towed to the end of the airport

towards a maximum security area.

Before this aircraft can enter the maintenance hangar

several important procedures are necessary.

The kerosene truck arrives.

It's imperative to evacuate the remaining fuel

in order to eliminate any highly-inflammable particles.

- There mustn't be any fuel left over

because we need to work inside the tanks.

For one thing there's the explosion and fire risk

and then there's the danger of toxic fumes

for those working around the aircraft.

- After several years of flight

grease has built up in the landing gear.

A team of five moves into action to clean this

high-performance monster.

The 777 is 64 meters long.

Its unladen weight is 142 tonnes or the equivalent

of 40 heavy goods vehicles.

Its engines are amongst the most powerful in the world.

The 777 has a flight range of 17,000 kilometers,

the distance from Paris to Sydney.

- Well when you think about the 777

and what it's been able to do, it really does

start with the engine.

It allows that airplane to fly those long distances

at fuel efficiency that we hadn't seen in the past.

- Just imagine, the diameter of each engine

is equal to that of the fuselage of a Boeing 737.

The last external operation, to retract from the hold

this enormous compartment.

This is where the crew can rest during long-haul flights.

It's the first time it's been removed in 16 years

and it's a complex operation.

- Hang on, wait a moment.

Go in front if you can get through

and push it from behind please.

- We're going to remove the container,

which will give us access to areas we can't usually get to.

That's something you never usually see.

- These are the beds where the crew can sleep.

This 777, registered as Papa Lima,

is ready for the heavy check.

- When the airline goes through a heavy check

it takes five weeks, but to be successful

they have to have very detailed plans.

- In addition to the regular

maintenance operations, heavy checks lasting several weeks

are carried out every four years.

Those carried out every eight years are a deeper inspection

of the aircraft's structure, and during the heaviest

of the checks, unveiled here for the first time,

the aircraft is literally stripped naked.

It's carried out every 16 years.

- This aircraft has had daily, weekly, monthly and more

extensive four-yearly checkups before arriving

at this thorough makeover.

- So for Papa Lima, this heavy check

is exceptional.

It will cost several million euros and will be the first

to take place in this brand-new hangar.

It has a gigantic surface area, 11,000 square meters.

This hangar, specially designed for heavy checks,

is the only one in France authorized

for heavy checks on a 777.

Thierry is this evening's team leader

who's directing maneuvers.

- Advance a bit more.

Keep an eye out, William.

Enough clearance there?

Make sure you're not too close there.

- Bringing the aircraft in is an extremely

delicate operation, it has a wingspan of 64 meters

while the door of the hangar is only 70 meters.

Which means there's just a six-meter clearance.

- Clearly if we move two centimeters at the front

the back moves a lot more, so we have to be careful.

That's why we have surveillance officers on each of the

docks to make sure we don't come too close and collide,

damaging the aircraft.

- The maneuver has to be inch perfect,

bringing the aircraft towards the scaffolding docks

without touching anything.

- If the aircraft is 50 centimeters to one side

it can't be docked, so we wouldn't be able to do the work

we have to carry out.

- The slightest impact between these 142 tonnes

and the dock would be catastrophic.

It's 11pm, but all the teams are here to witness,

for the first time, a 777 entering the new hangar.

- We didn't touch anything, it's perfect.

Mission accomplished.

- This 777 will be submitted to 15,000 hours

of work, 9,000 hours of structural inspection,

and 6,000 hours given over to updating of equipment.

15,000 hours, just imagine if one mechanic had to carry out

all the work, it would take a total of seven years.

Papa Lima's interior is going to be completely emptied.

The objective: to inspect the aircraft, in particular

its structure, and upgrade the entire cabin.

A unique occasion to scan this gigantic beast.

The next morning.

The first week of the overhaul begins.

The Air France teams have worked all night.

The priority: to raise the aircraft in order to

get at the wheels and the landing gear.

For that they use what are known as actuators.

Astonishingly the enormous 777 can be balanced

upon just three points.

Two actuators in front, close to the wings

and a third one at the back.

Each of these actuators is capable of lifting 75 tonnes.

This is thanks to a system of hydraulic pistons.

Frédéric Roi is in charge of this important operation.

- The aircraft weighs 142 tonnes, in order to carry out

the maintenance we move the landing gear and various

other equipment, we place it on three actuators.

One at the back, two at wing level, which allows us to lift

the entire mass of the aircraft.

- Thanks to these three pylons,

the landing gear is no longer touching the ground.

142 tonnes are suspended in mid-air.

A second work site safety element: these gigantic docks.

Those surrounding the vertical stabilizer

are more than 18 meters high.

- This allows the personnel to work in safety and without

damaging the aircraft.

- This made-to-measure,

1,600 square meters of dock are an indispensable element

for a heavy check.

They make it possible to work on the roof of the aircraft

and to get inside the tanks,

as well as to inspect the wings.

- We've provided access to the entire wing surface

including the underside, both sides of the aircraft,

and also the forward fuselage section.

- That's it, the aircraft is stabilized.

Its doors can now be opened.

At first glance all the interior seems to be intact.

The cabin isn't in a bad state, but these 250 seats

have been here for years.

Everything must be totally replaced and improved.

The teams move into action.

In total, 500 people will directly intervene

for this heavy check.

- We will take it straight out.

- The cabin will undergo a total metamorphosis.

For example, the entire video system will be changed

to make room for fiber optics.

- One of the things that 777 has been able to do

is incorporate new technologies, especially those

technologies when it comes to cabin entertainment,

when it comes to the passenger experience.

- New screens will be installed on the aircraft

which will be larger and undoubtedly higher definition.

- Everything is quickly removed from inside

the aircraft, except, paradoxically, the cockpit

which won't be taken apart but simply verified

during this heavy check.

- Everything's moving extremely quickly.

We can see how everybody is swarming around the aircraft.

It's the same all night long; they're open all hours.

- In addition to the Air France teams

a dozen or so outside contractors are involved.

- It's a big removal operation.

It's always impressive whenever you see these huge machines

with millions of pieces, it's just unbelievable.

- The toilets, the galley where the food

is prepared, the whole cabin is taken apart

during the course of the day.

Every piece is precisely cataloged and set aside

for renewal.

The current inside the aircraft is disconnected

so that work can carry on in complete safety.

- We cut off the power supply.

There's no more power on the aircraft, no electric power

or hydraulic or pneumatic power either,

which allows us to carry out several weeks work

in complete safety.

- Neon strips, powered through the hangar's

electrical system, are put in place for five weeks.

A vast operation begins, the removal of one of the

trailing edge flaps.

A central element which plays a vital role

during each takeoff and landing.

During these delicate phases it's these flaps

which vary the amount of lift on the wings.

An aeronautical mechanic, Thomas, takes us under the wing

to outline the problem of corrosion and the effect

it has on the structure.

- We've already pinpointed the corrosion on the inside

which requires us to remove the flap and thereby

carry out a structural inspection.

- Four mechanics are involved.

The operation is delicate.

The part weighs more than 800 kilograms.

Closely fitted into the structure of the aircraft,

the flap jams.

- Lift it up a bit, try backing up.

- It's moving, it doesn't seem to be twisted.

- They must be careful not to use too much force

because of the danger of damaging the aircraft's structure.

The aluminum fuselage is very thin.

- As for the structure, it's more fragile, it's all

honeycomb and composites, and the slightest knock

could damage the flap.

- Once the piece has been disconnected

it's carried through the air by this rolling bridge

28 meters overhead.

Once again, precision is of the essence.

- It takes a lot of communication between colleagues

to avoid collision between the aircraft and the part.

Not to mention injuring somebody

if they become trapped between the two.

- Detaching the flap has taken all morning.

This part will now be examined and, if necessary,

taken to a workshop for repairs.

- The next morning, at 7 o'clock,

a strong-arm team has moved in.

Today's challenge, to remove the 250 seats.

- We mustn't mess up the preparation.

It has to be done quickly.

The aircraft arrives and we remove the seating immediately.

- The objective there is to go in

and take a look at the structure

so everything has to come out of the aircraft.

- This heavy check includes the modification

of the entire cabin.

All the seats will be replaced with the updated version.

In half a day the cabin is completely emptied.

On the shop floor, the rows are placed in numerical order

because the seats are to be recycled for other aircraft.

- Here's 43, 42 there. - Yeah, okay.

- A reconstruction of the cabin is laid out

in the hangar.

These seats will be replaced with the new model,

each of which is worth several thousand euros.

In hangar number 3 HN3 the day and night shifts

pass the baton back and forth 24 hours a day.

Today's operation: to remove the window panels,

the decorative layer which separates the cabin

from the outer shell.

This will facilitate the inspection of the structure

which is just behind the thermal padding.

- It's a composite panel which is very, very thin.

It's basically a decorative panel

which serves as a surrounding for the porthole.

- This is rock wool or mineral wool

which is covered with two skins.

They are joined to form a mattress.

It's used as thermal insulation.

- And of course, after years of flying,

dust has accumulated behind these window panels.

Over the course of the morning

the window panels are taken to the workshop.

This workshop has been set up specifically

for the heavy check.

It's positioned a few meters from the 777 platform.

As one job makes way for another inside the aircraft,

so it does outside.

A very sensitive part of the aircraft is examined.

It's known as the electronics bay.

This compartment is situated

in the forward section of the aircraft.

The bay has been stripped down.

This is the very nerve center of the 777.

- Everything to do with electric cabling is also inspected

to look for wiring problems.

Any cables outside of the tolerance range

have to be replaced to bring the aircraft back to its

normal configuration.

- From a systems perspective we were able to optimize

our cabling, optimizing the system

so it could be maintained.

It could be upgraded over time as well.

- This avionics technician is in charge

of verifying each element of this supercomputer.

- So we're underneath the cabin floor

more or less below the first-class passenger seating area.

This is where the bulk of the aircraft's calculators

are situated.

- And when we ask him how many cables there are

this is the reply.

- I can't tell you precisely how many cables there are

but there are thousands, stretching out

over several hundred kilometers.

There are flight command cables, radio communication cables,

fire detection cables, onboard video cables.

There are many different circuits

passing through these strands of cable.

- And during the heavy check

they need to be verified one by one.

The same operation needs to be repeated hundreds of times.

This portable machine can detect the slightest malfunction.

Any trace of wearing constitutes a potential danger.

- There are different types of problems

associated with cables.

There's corrosion linked to cables coming into contact

with humidity or those where the insulation

has been damaged.

- These danger tags indicate circuits

which are being tested.

At the same time the numerous cables

linked to the old video system are removed

during the course of this heavy check.

They will be replaced by fiber optics;

new, faster cables for the updated video system.

We're already into the second week of the operation.

Time to begin the CPCP,

the Corrosion Prevention and Control Program.

A far-reaching examination which only takes place

every 16 years during heavy checks like this one.

- No signs of corrosion, good.

In order to inspect the structure behind

the insulation blankets they all need to be taken out.

Then we do a thorough visual inspection

for signs of corrosion in the aluminum sections

of the fuselage.

- It's extremely rare to find signs of corrosion

on a 777 during these checks.

That doesn't alter the fact that corrosion is always

one of the major preoccupations in terms of safety.

Of course corrosion is linked to humidity

inside the aircraft.

At an altitude of 10,000 meters it's -50 degrees Celsius

outside and 25 inside.

This temperature difference generates a large amount

of condensation which can drench the insulation blankets.

Another cause of humidity is the breathing of the hundreds

of passengers inside the cabin.

The result is that certain water-soaked blankets

can lose their properties of insulation.

- We've identified a zone which is more susceptible

to having damp insulation blankets,

and that is around the doors.

You can see here how the glass wool is in shreds.

It's non-existent, that's the water.

If I open the blanket it will drip.

A large blanket can cost up to 3,000 to 4,000 euros,

and during a heavy check like this

we may replace between 60 and 70 of them.

- And it's particularly around the doors

of the aircraft that humidity seeps into

and attacks the blankets.

Theoretically the work is precisely orchestrated

and yet there are unforeseen problems

which inevitably arise.

Today it's the dismantling of the landing gear

which is giving the team a serious headache.

- When you work on the landing gear

you're dealing with heavy parts.

They're not very often taken apart, every six years at best.

Sometimes every eight years.

- Today's task is to take out the central axle,

a part which runs right through the landing gear

and whose chrome becomes extremely warm.

But after two hours the axle still hasn't budged an inch.

The whole landing gear structure is weighing down on it.

So three additional mechanics come and lend a hand.

- These are people who are passionate about their work.

When they have a colleague who is struggling

with an important and delicate task, there's a solidarity

from other team-members who come to help, suggest solutions,

offer different ideas.

- Go ahead, be careful.

- The solution they've gone for

is lifting the landing gear to relieve pressure on the axle.

- I'm going to try and lower it a bit but be careful.

- God, what a nightmare!

- Get back, get back!

- You sometimes need to reflect on how to do something,

how to go about it, what tools to use.

- Done.

- That was the hardest, right.

- After eight hours of hard labor

the central axle is finally taken out.

It will be scanned in a special laboratory

to detect any worn chrome.

As the teams gradually take apart the interior of the 777

the logic behind its construction becomes more apparent.

The interior fittings are extremely thin.

In reality, you're only a few centimeters

from the outer shell.

- The structure is here, a bit of insulation with some

cables in front of course, and behind that the fuselage.

It's not very thick.

- It's not very thick.

The bottom line for an aircraft is to have as little weight

as possible.

- That's right.

- There's not between the passengers and the exterior.

A few centimeters, not much at all.

Weight is the enemy in aviation

so we try to have the least number of things possible.

- When you're seated in an aircraft

your head is almost in the clouds.

The plating of the fuselage is extremely thin.

Only a few millimeters, and yet this structure

needs to resist enormous pressure and twisting.

- Think about it.

You're sitting in a seat traveling at 500 miles an hour,

and you have a piece of composite or a piece of metal

a few centimeters thick between you and the outside,

and you can do that in ways we've never

been able to do before.

So I think part of the passion for aviation is the magic

that goes along with flying.

There's no other experience like it.

- There are one or two millimeters of plating, that's all.

- Consequently the structural inspections

are carried out with extreme vigilance.

Activity on the work site carries on through the night.

- We never stop, we work what we call three by eight.

In other words morning, evening, night

plus Saturday and Sunday.

- 24 hours delay in finishing the aircraft

is out of the question.

While confined to the ground it costs

several thousand euros per day.

While flying in extreme conditions an aircraft,

despite having been designed for it,

can undergo difficult challenges

such as lightning, which can represent

the electrical power of 40 power plants.

- An aircraft going through a storm in a cumulonimbus cloud

with hailstones and lightning is a problem for the fuselage.

- The very thin fuselage

can be seriously damaged in these conditions.

- Hailstones can obviously present very serious problems

because depending on the size of them they may inflict

structural damage to the aircraft, both to the metallic

and composite elements.

- In these extreme conditions the aircraft

is of course immediately inspected after the flight.

But the heavy check allows for a detailed and

precise inspection of the entire fuselage.

- Here we have a zone where something's been spotted

by a technician.

It might be a scratch, an impact caused by a collision

with a bird or anything else.

- Once these zones have been identified

the section of fuselage needs to be stripped back.

This paint technician uses a highly powerful stripper

which attacks the paint.

Once it has flaked the plating appears.

At this point it's possible to precisely measure

the importance of the impacts.

- Nowadays, technicians can come with radio equipment

to see if there are cracks in the metal

which are invisible to the naked eye.

- 10 years ago the fuselage

of the mythical Boeing 747 was systematically stripped back

during each heavy check.

The entire paint covering was scraped by hand.

Once it was stripped, the 747 went through the heavy check.

Obviously, it was completely repainted afterwards.

Today the process has changed.

The 777 is not systematically repainted

during a heavy check.

During flight at an altitude of 10,000 meters

and at a speed of more than 900 kilometers an hour

the pressure on certain parts of the aircraft is strong.

Pressure which provokes wear and tear.

The aerodynamics are such that when the aircraft

flies at full power it's the forward section

which cuts through the air which is the most exposed.

The airflow hits the nose of the aircraft

and the leading portholes which, over time, creates

very marked scratches which are plainly visible.

The detailed verification of these portholes

starts in the third week.

After years of flying some are scratched, leaving the glass

virtually opaque.

Air pressure has a truly detrimental effect.

- Given that for reasons of aerodynamics the aircraft

comes to a bit of a point, the wind effect at high-altitude

damages the portholes, as you can see.

And it is the first five or six which are the most affected.

- So specialists verify the portholes

ones by one.

They put markers on those which need to be changed.

- We're going to take the next two out because they are

clearly worn, in marked contrast to the next ones

which look virtually new.

They will be left as they are except for a little cleaning.

The portholes judged to be in a bad state are unscrewed.

That's when it becomes clear that they're only held

by a dozen screws.

It is to a large extent the pressure inside the aircraft

which holds the portholes in place against the fuselage.

- That's it.

The porthole's composed of three parts.

The joint, the outside part and the inside part.

The Boeing 777 has 115 portholes, each one double glazed

with an outside pane and an inside pane.

They're fixed to the structure of the aircraft

with small screws.

But it's not just the portholes

which succumb to wear during flight.

Each time the aircraft climbs in altitude

the fuselage does not remain rigid.

Effectively, each time the aircraft climbs and descends,

the fuselage inflates and deflates

under the effect of pressure.

To ensure that the passengers are comfortable

and can breathe normally, the pressure inside the cabin

is artificially raised.

This is called pressurization.

- These phases of pressurization and depressurization

of the cabin create movement like a balloon

which inflates and deflates.

These heavy checks allow us to inspect the whole structure

to make sure there are no problems.

- The result is that wear and tear

on the aircraft is greater during short flights

than during long-haul.

In the course of one day five Paris/Nice flights

are far more taxing on the aircraft

than one Paris/Los Angeles.

Today it's the turn of the toilet compartment

to be taken apart for renewal.

It's a primary location for humidity

and therefore it has to be treated with care

because as we have seen, on board an aircraft

humidity is an enemy.

The compartment is taken to the workshop.

The forward toilets are situated just above

the electronics bay, the nerve center of the aircraft.

In the workshop two structural mechanics are at work.

They completely dismantle the compartment

which has taken a beating.

Part of the aluminum framework,

which holds the panels together, are individually remade.

This requires precision craftsmanship.

- We have to change this metalwork

which has been completely corroded by urine.

It has produced an electrolysis effect

causing this heavy corrosion.

There's sometimes a lot of damage.

Like here, where the aluminum is corroded

to the point of having holes in it.

So here we obliged to cut out sections

where it is literally falling apart.

- The rail is completely broken.

The main panel from the toilets

has been taken to the back of the workshop.

The honeycomb structure, which has also been attacked,

has had to be completely rebuilt.

A new aluminum frame, built by these specialists,

is put in place.

- A badly directed pee-pee can cause a lot of damage.

Take a look at this,

it just goes to show how acidic urine is.

And aluminum doesn't like acidity.

- The central toilet panel is ready.

It's fixed back on to the main compartment.

It's surprising to see just how thin

these interior fixtures are.

Put back together like a kit, the cabin is stood back up.

Once the structure is ready the interior will be redone.

Don't forget that underneath this cabin

is the electronics bay and there is no question of humidity

being allowed to attack the cables.

During the heavy check the two general electric engines

are inspected.

For security reasons the inspection has to be in accordance

with a strict protocol.

Every piece, every nut and bolt,

has to be what they call traced.

Because in this domain, there's the danger of counterfeits.

- It's true that there is a world market in counterfeit

aeronautical parts.

Consequently we have to be extremely vigilant when we buy.

All the parts we buy, be it screws,

engine blades or raw materials, we have to have

the maker's certificate of conformity.

- And vigilance is maximum.

These two engines are fundamental strong points of the 777.

They are astonishingly powerful.

Believe it or not, in an emergency situation

the aircraft is capable of flying with a single engine

for more than three hours.

- When you take a look at that 777 engine

people are just absolutely amazed at the size,

the diameter of the engine.

And, frankly, it is a big engine.

To generate that 115,000 pounds of thrust the cross-section

of the 777 engine, is the same as the cross-section

of a 737.

- These two engines are the force behind the 777.

A twin-jet competing against quad-jets, this aircraft

is incredibly powerful while consuming less fuel.

Contrary to what you might think, an airliner deteriorates

on the ground not just in flight.

One apparently anodyne operation has an impact

on the aircraft: the loading and unloading

of luggage and freight.

Each time that the loading platform approaches the hold,

the slightest knock can damage the fuselage.

And when you think of the price of a bent car panel

just think what it is for a Boeing.

What's more, the loading rollers within the cargo bay

are highly solicited.

Over the years, millions of tonnes are loaded and unloaded.

Today, two mechanics are checking out this bay

to estimate the extent of the damage.

- We test the rollers to make sure

that all is working correctly and that there's no

wear and tear or severed electrical cables.

So here we have two rollers which are very worn.

They'll either be replaced or sent to the workshop.

- A few hours later, this is what

the bay looks like.

Just walls and ceiling, everything's been stripped out.

The mechanics can now replace the defective rollers.

We are entering the fourth week.

The aircraft is empty, and the Air France teams

are going to start re-equipping the 777.

There's a constant flow of activity.

There's one particularly perilous job:

the inspection of the fuel tanks, situated inside the wings.

A specially trained mechanic climbs inside to make sure

there's no corrosion.

It's a dangerous operation because it takes place

in dark and cramped conditions.

Only a few days ago there were a 171 tonnes

of kerosene here.

It's forbidden to stay inside for longer than a few minutes.

During the entire operation, a guard is on hand

to make sure all is well.

He is trained to carry out an emergency evacuation

should the mechanic inside become unwell.

Once the internal inspection is over

the technician comes back out.

The operation is repeated for each of the fuel doors.

Inside, the panels are unscrewed.

The state of the center tank has to be verified.

This section, situated between the two wings,

is strategic for the structure and therefore

for the aircraft's safety.

Outside, the inspection of the fuselage comes to an end.

The mechanic rubs down the signs of wear

centimeter by centimeter.

In the workshop, the overhead luggage compartments

are lined up.

They are brought back to their original condition by hand.

Cabin technicians take care of this time-consuming work.

At the same moment in the workshop

the portholes are repaired.

The scratched parts are removed.

This technician is in charge of installing

the new Plexiglass.

- It's a bit like when you put a transparent film

over your smartphone to protect the screen.

It's the same thing for a porthole.

It's the Plexiglass which is damaged

instead of the porthole itself.

- The new parts have to fit perfectly

to the old structure.

With a porthole, the slightest breach of insulation

could be extremely dangerous.

- It's definitely a lot of work, but though it may not

seem like it, it's a question of passenger safety.

- The portholes are brought inside the aircraft

to be fixed in place.

Inside the window panels, along with other

interior fittings, have begun to be put in place

over the last 48 hours.

The repaired portholes are as good as new.

- This is for phonic insulation.

It allows passengers to be protect from outside noise,

from the engines for example, without having to touch

the porthole itself.

- Now comes the turn of the luggage compartments

to be put back in place.

They have to make sure that the various electrical cables,

the new TV connections, the ventilation system etc,

are all correctly installed.

- The various ducts and electrical connections

need to be checked to make sure they're working

and correctly positioned.

The cabling is fine, the supporting beam is ready.

We checked the fixing and the integrity of the blankets.

We see here they're virtually as new.

The oxygen is hidden behind here, so we're ready

for the fittings.

- And they're ready.

The reconstruction can begin.

- The luggage compartments are fixed to this rail

which runs the whole length of the aircraft,

and they're fixed with these clips at the top.

- We're too far back, we're too far back.

- As with all the cabin fittings

the luggage compartments are extremely light.

They fit precisely into the structure of the fuselage.

- The positioning of the luggage compartments

is very precise.

Everything has to be just above the passenger's head

so that the positioning of the oxygen masks

and light fittings are perfect.

- Once the luggage compartments are fitted

another team takes over to check out the different conduits.

This includes checking one central safety element,

the oxygen masks.

- We've just checked all the oxygen pipes which allow

the passenger masks to be release on the pilot's order.

So when I press here the mask automatically falls

in front of the passenger's face.

- These oxygen masks are vital

in the event of depressurization.

It is essential that they be folded in the right way.

The protocol is meticulous to ensure that should they be

needed, the masks function immediately.

The aircraft is now ready to receive

the principal cabin fittings.

The new seating, which has been brought into the hangar.

This heavy check is exceptional.

Not only for its 16-yearly revision

of the general structure, but also because the aircraft

will benefit from an important upgrade.

- We make use of this evaluation of how well the aircraft

is aging to make cabin modifications, upgrading to the new

generation with better screens and improvements to

passenger comforts, both in business and economy class.

- You know, when we design the airplane we worked

very closely with our customers on the 777

to make sure that we would provide the kind of

passenger experience that they wanted.

And what our customers told us, the airlines,

is you have to think about the future.

You have to give us flexibility.

So our airline customers, whether it be Air France

or others, are really being able to use the 777

as a platform for new technologies

in order to provide the kind of experience

their passengers want.

- Little by little, the new, high-tech cabin

takes shape.

These special seats are true technological gems.

- I'm seated in business class.

In front of me I have a large, full HD color screen.

I can play online, text my neighbor.

It's really top of the range.

- Each of these state-of-the-art seats

is worth more than 50,000 euros.

At the same time, other technicians are putting

the finishing touches to economy class.

The latest screens are also installed here.

In a few days time, several hundred passengers

will be able to make use of them.

One of the last operations is extremely delicate.

Two aviation technicians, equipped like mountaineers,

climb onto the roof of the 777.

They need to reinstall the satellite antenna.

This antenna relays all of Papa Lima's communications.

This essential element is replaced during the heavy check.

It's quite a balancing act.

- You can feel the cutoff date getting closer

when the aircraft has to be delivered.

There's definitely a certain effervescence

during the final days before the aircraft is handed over

to the crew, who will take charge of the passengers.

- The night before the aircraft leaves

one of the most impressive tests takes place,

that of the landing gear.

It's a part which, by definition, is central to every

landing and takeoff.

The nose and rear landing gear is raised and lowered

at various speeds.

From the pilot's seat, the electrical and hydraulics

circuits are reconnected.

The various flight commands are tested.

- Okay, I'm cutting the hydraulics.

- Obviously there's a lot of stress during the last week

before the aircraft is delivered, when the systems

are rebooted and tested and unforeseen details

can shake up the schedule.

- The weather radar, positioned in the nose

of the aircraft, represents the eyes of the Boeing 777.

It wasn't removed during the visit, but it is verified

one last time.

For an aircraft, weight is a crucial element.

Following so many modifications, it's important

to do a weight check.

With its new business cabin, Papa Lima doesn't

weight the same as it did when it arrived.

To calculate the unladen mass, the aircraft has to be

put back onto the three actuators.

A gigantic electronic weighing machine

has been connected to the top of each actuator.

Each one is capable of weighing more than 70 tonnes.

- I've raised it sufficiently to enter the fairing.

I can lift it some more.

- Each actuator is now connected

to a central console.

- Here's the console for the right actuator.

This is the console for the tail actuator.

And this one is for the left actuator.

Adding the three together gives the total weight.

From here, the weigh in is child's play.

It can be done with one finger.

- With this one little button

we're going to lift 142 tonnes.

To eliminate the risk of error the aircraft is weighed twice

successively.

The margin of error between the two results

must not be above one in one thousand.

- You mustn't have any drafts.

All the hangar doors need to be closed

and there mustn't be anybody on board at the time.

And now it's underway.

We're at 142 40, and the first was 142 tonnes

and 50 kilograms, so it's virtually identical.

- Once the weight has been validated

the teams will calculate what is known as the balance

of the aircraft, this is to make sure that the center

of gravity of the 777 hasn't changed.

They have to be sure that the weight of the aircraft is

well-distributed.

Neither too much towards the front, nor too much towards

the rear.

Otherwise the aircraft could be unbalanced.

- If the center of gravity is too far back, the aircraft

would take off tail heavy.

It wouldn't be able to level out after takeoff.

- Mass distribution has to be such that the aircraft

in flight holds the optimal position for air penetration.

- Following the unladen weighing,

the finishing touches can be put to the interior.

And nothing is left to chance.

Obviously the new connections, as well as the electrical

systems, undergo one last verification.

- The aircraft is going out in a few hours so we now

carry out the last checks to see that everything is optimal

for the passengers.

- These yellow boxes are connected

under each seat to simulate computer connections.

They have to make sure that if there's a short circuit

in one computer the rest of the system

continues to function normally.

- We need to quickly test while we still have access

before the aircraft leaves in the next few hours.

- At the end of the cabin the new

galleys are in place.

Throughout the aircraft technicians test the new tactile

screens.

Lighting tests are carried out from the pilot's seat.

In business class, the new, high-definition video systems

have been connected.

- When it leaves it'll be like a new aircraft, direct from

Boeing.

- An aircraft which is even more

high-tech than it was when it first left the factory.

The big day has arrived, Papa Lima is ready

to leave the hangar.

This checkup has been a renaissance.

The enormous metal doors of the HN3 are opened.

The head of maneuvers gives the signal.

- We're happy to see her leave, all the same.

It's the result of five-weeks work.

- A curious ballet is prepared during the night.

The towing equipment is connected to the aircraft.

The docks are prepared for the departure.

- We're all happy, it's been a lot of work.

We've been committed to this overhaul and it's satisfying

on the last day when the aircraft goes out.

I think everybody is proud to deliver this aircraft.

- Everyone is in position.

As the aircraft leaves the hangar

Papa Lima begins a new life.

During the next 24 hours it just remains for the

Air France teams to carry out engine tests

outside the HN3.

Once these tests have been validated, this 777

will be operational.

The challenge has been met.

In 48 hours it will be delivered to its crew in Roissy.

Bang on time.

Its next flight to Montreal is already scheduled.

Papa Lima disappears into the night.

It's been an impressive exercise.

In five weeks, an aircraft has been completely taken apart

and put back together.

It's thanks to these overhauls,

carried out by highly skilled teams,

that airline companies can provide maximum safety

and that the Boeing 777 is one of the safest aircraft

in the world.

These heavy checks are not only a technical challenge

but also recount a remarkable story of men and women

united in their passion for aviation.

- The first time you board an aircraft

and do what we've just done, empty it

and strip it down, gives you a strange feeling.

It's an impressive thing to see.

- There's a passion, there's a pride,

there's a sense of ownership.

- And it's thanks to this knowhow,

thanks to this endless collaboration

between engineers, constructors and mechanics

that the 777 goes on improving.

- Air France has been one of those customers

that have really pushed us to make the aircraft better.

And that's how, day after day, year after year,

the future of Boeing is constructed.