Original subtitles

At the edge of space,

a spy plane keeps vigil on the world's hot spots.

The most badass airplane in the world.

Flies higher and longer than any other plane.

While the biggest cargo plane in the US fleet...

- This is a behemoth. - ...flexes its muscles

to equip troops around the world.

We can go anywhere, any place, any time.

And the most durable fuel tanker

on the planet keeps the Air Force in the sky.

Ten feet. Five feet.

All right. Bring it in.

This airborne infrastructure works kilometres

above the surface of the earth

to support the most powerful military in the world.

This is the KC-135,

the Stratotanker.

It's a flying gas station,

the Air Force's longest-serving air refuelling platform.

Delivering up to 200,000 pounds of fuel.

The mission is to fuel.

Juicing up planes in flight.

Camp gas to the receiver straight from the wing tanks,

the main tanks here.

This has been refuelling forever,

and we'll continue refuelling forever.

Right now, we have four receivers on us.

It puts the power in air power.

We have the two receivers on the left wing.

It's been doing so since 1960.

And when you need gas, I'm your best friend.

Sir Isaac Newton showed

that what goes up must come down,

and that's true,

unless the KC-135 Stratotanker

has your back.

The KC-135 is literally a gas station in the sky.

It flies fuel thousands of metres up

and pumps it into planes.

That's why it's the linchpin in a global network of flight.

Jimmy, tell them we just freed up

an extra 6K if they need it.

The Stratotanker is the thing

that keeps other planes in the air.

That's important because there are over 2,000

US Air Force planes flying around the world

at any given moment.

It wouldn't be possible without the Air Force's fleet

of hundreds of KC-135 Stratotankers delivering

aerial refuelling day-in and day-out,

as it has for decades.

And today's mission is to gas up

four thirsty F-15s waiting for fuel.

Keeping a giant tanker in the sky

requires some heavy-duty engines.

We've got four of these engines on the aircraft.

Each engine delivers about 22,000 pounds of thrust.

That allows us to take off

with 200,000 pounds worth of JP fuel.

I really love flying this airplane

because it's a lot of power

and you're just controlling it with your two arms.

It's like a car without power steering.

You're in control 100% of the time.

The pilot may be in control of the flight...

All right, one's going to the boom, one's going to the wing.

Copy.

...but on the KC-135,

the boom operator is just as important.

That's the specialist who guides a telescopic hose

weighing over 100 kilograms

into the fuel tank of a plane running on empty.

Where we're standing right now, the fighter jet comes in here,

he expositions himself behind the boom,

and then receives the juice from us.

Looking at the boom, that part extends out about 12-13 feet

and that's what the receiver makes contact with.

Walking over here, you'll see

the boom operator positions themself

right here in this window and they're observing everything

that happens behind the aircraft.

So, you've got your boom operator

lying down in the back of the plane,

looking over a small porthole window.

They're actually maintaining visual contact

with the receiver just using their eyeballs.

So, we rely on the boom arm to let us know,

"Hey, the receiver's too far to the left, too far to the right,

"too aft, or getting too close to the aircraft."

Once the lead aircraft is done, he manoeuvres to the right,

and then his wingman comes from the left,

swings down right behind the boom, the boom comes down,

gives them the juice, and then manoeuvres to the right

at the completion of air refuelling.

They're depending on us, and we're depending on them.

And dependability is the KC-135's calling card.

The Stratotanker entered service in 1957.

And before each KC rumbles out to the tarmac,

a crew member will investigate a critical piece of equipment

to ensure the plane is safe to haul up

over 90,000 kilograms of jet fuel.

We are going to access

a integral part of the aircraft.

It's called the firewall shutoff valve.

It's in-between the reserve tank

and the number one tank, which are both filled with fuel.

The shutoff valve

is a small piece of metal with a big role to play,

preventing fuel from igniting onboard.

Fuel shutoff valves are critical in aircraft.

They provide the ability to stop

the massive amount of fuel onboard from feeding a fire

that could result in a mid-air explosion.

Attention to these details is partially due

to lessons learned in war.

Safety measures like shutoff valves

and dry beds were given prominence

when the Air Force determined that almost half

of all aircraft losses in the Vietnam War

were due to onboard fuel fires or fuel explosions.

They were looking for ways

to make having tons of fuel in the air safer.

It's important that it works

before it gets out of the hangar because,

if they fail, people's lives could be in danger.

It's the last line of defence.

This is one of the hardest components

that we have to change.

You're working in a space probably that big.

So, this is the dry bay,

and we are now looking for

our firewall shutoff valve.

Staff Sergeant Tyler Hawthorne

has to manually trigger the valve,

then listen closely to confirm it's doing its job.

He needs to hear a spinning sound to know the valve

is working properly.

That's the firewall shut-off valve.

And then, we're gonna actuate the lever,

see if this valve works.

There it is.

It works.

It's kind of crazy that something so small

could be so important.

But it's well worth it because,

in the end, you know that you're saving lives

in the event of an emergency.

She's ready to fly

and we're ready to refuel and put her in the sky and,

yeah, man, it's a good day.

Great day to be in fuels.

Out on the flight line,

a KC-135 gets ready to rock.

It's time to load the liquid cargo

for the F-15s in need of a fill-up.

What's up, brother?

- What's up, boss? - All right.

The US Air Force uses over seven-and-a-half billion

litres of fuel a year.

It would take more than 65,000 KC-135s

to move it all in one shot.

We're gonna put on fuel onto the aircraft through this SPR -

the second point refuelling receptacle right here.

And from here, it's gonna distribute out to the fuel tanks

that we're gonna use to offload to other aircraft in the air.

We refuel up there, but it starts right here.

All right, ready?

The really important fuel tanks

are a set of three lining the underside of the fuselage.

They're independently sealed.

They've got separate pumping systems.

All that fuel is being pumped down through a series of pumps

in the back of the aircraft, up into a long mechanical boom,

and then right out the back of the plane,

into whatever it's refuelling.

Now, we're going to go do a leak check on the boom

before we send up the aircraft.

A mid-air fuel leak

would be wasteful and dangerous.

So, we're going to pay particular attention,

especially to around the nozzle poppet area.

We don't want to be sitting there,

spraying the other aircraft during AR,

losing all that fuel in the air.

And you can see the fuel

is actually filling up in the boom currently,

and you can see, like,

little minor movements of it pushing out.

The little popping movements on the nozzle

confirm there are no leaks where the two planes will connect.

If there were, fuel would be dripping from the edges.

So, if you have a fuel leak

where the boom is going into the other aircraft's receptacle,

you could be spraying anything from their windows

or getting sucked into their intakes in the engine,

which could be bad.

The airplane could crash kind of bad.

The first mid-air refuelling happened in 1923,

over the skies of California,

where two de Havilland DH-4B biplanes

passed fuel to one another.

The receiving pilot actually had to reach out of his plane,

grab a hose, and use a hand-operated valve

to transfer about 75 gallons of fuel into his aircraft.

It was an extremely important moment

because air-to-air refuelling developed into something

that has made the idea

of long-range global air travel truly possible.

Today, it's a routine operation,

but filling the Stratotanker with fuel doesn't come cheap.

All right, 31,000 gallons, at $5 a gallon,

would be about $155,000.

That is a hell of a fuel bill.

All right, we're done, we're wrapping up.

Yo!

The Stratotanker now has a belly full of jet fuel.

That means it's go time.

Going left, pilot. Copy that.

Step out.

- Clear to go. - Pilot.

Okay, thanks.

Ready.

Approaching right.

Roger. Gear up.

Sporting a wingspan of over 40 metres,

standing almost 42 metres high and 41 metres long,

it's half the size of a city block.

It can kick ass and haul gas

anywhere it's needed in a 2,400-kilometre radius.

250 seconds, gears up, flaps up, rudder pressure lowering.

Awesome.

The KC flies at over 850 kilometres per hour

to reach its track -

a designated location of airspace for air refuelling.

The tanker has a date with four

F-15 fighters that need to get juiced up.

We're trying to get to the track a little bit faster.

Requesting a direct.

So, right now, we're going to this point.

The KC-135 Stratotanker

has to get to the refuelling point

before the thirsty F-15s arrive.

Now, we're trying to get over to this point,

so we're trying to cut that corner and save some time.

KCs operate all over the world,

including in active combat zones.

If a crisis situation required the KC-135

to offload all the fuel

in each of its ten tanks to other planes,

that means the aircraft wouldn't make it home.

Can we give them all of our gas if we had to?

We can give them all our gas, if it came to that, yeah.

We have certain operational directives.

Our job is to make sure the receiver has gas,

so there's bombs on target.

We'll do whatever it takes.

You think we should go back now then?

Yeah. Get the boom ready to go.

All right, Pilot, let me check on ops in the back.

Roger.

When the KC-135 is delivering fuel to the receiving aircraft,

we need to essentially connect the fuel tanks

inside the KC-135 to the fuel tank of the receiving aircraft.

Senior Master Sergeant Lindy Campbell

makes her way to the boom pod -

the cramped horizontal area at the rear of the plane

where she will command the refuelling process.

I'm going to lower the boom right now.

This lever lowers the boom.

As the four F-15 fighters

arrive at the rendezvous,

a delicate dance begins.

You guys have visual?

They're, like, at our seven o'clock.

10-4.

Right on us.

Now, they'll need to hold steady,

as she precisely guides the KC-135's boom

into the F-15's fuel receptacle -

a target only about 100 centimetres wide.

Thirty feet stable.

Ten feet.

Five feet.

Alright, bring it in.

Prep for air is complete.

Copy, check. Looks good in the back, as well.

Connection complete.

That was pretty cool.

With the boom connected, it's time to start

pumping the gas at a rate of over 3,000 kilos a minute -

enough to operate a family's car for two years.

Right now, we have four receivers on us.

We have one on the boom and we have one on the right wing.

We have the two receivers

that are waiting that are on the left wing.

We've probably offloaded about 1,000 pounds

of 4,000 pounds so far.

That's one plane done.

Now, to fuel up the others.

Right now, I'm making sure that he's staying inside

the air refuelling envelope by using these gauges.

These gauges tell me relatively where the boom is.

So, right now,

he's about three degrees to the left

and 30 degrees elevation. So, he's looking good.

The boom is the business end

of an interconnected network of onboard fuel lines

containing 50 valves and 15 pumps,

guiding tons of fuel to where it's got to go.

All that fuel is being pumped down through a series of pumps

in the back of the aircraft, up into a long mechanical boom,

and then right out the back of the plane.

Got him in tight at six o'clock. Just one.

Two down, two more to go.

It's up close and personal.

The boom operator

is lying only about six metres over the cockpit

of the receiving aircraft.

With fuel flowing between them,

it's the most dangerous moment of the mission.

I want some pilots listening to me.

We're flying two aircraft very close together

at very high speeds, which is really dangerous.

So, we are in charge

of making sure that they're maintaining a safe distance

and they're not getting too close.

During air refuelling,

everybody's listening to the boom operator -

the receiver pilot is and the tanker pilot.

The third plane takes all its fuel

and the last one jockeys into position.

It's one hell of a stick shift,

but skilled muscle memory

and focused concentration get the job done.

This is the ruddervator control stick.

It flies the boom up, down, left, and right.

So, that way we follow the movements

of the receiver aircraft until it's in a good position

to where we can extend the boom and make that contact.

All right, that's it, out of gas.

64,000 kilograms of jet fuel pumped into four tanks

equals one completed mission.

There's a trigger right underneath here.

That's how I trigger

a disconnect when we're done with the air refuelling.

All right, bring it back up.

The KC-135 heads back to base, having done its duty.

The Air Force's fleet of Stratotankers fuels up

about a quarter million planes annually,

and it's got no plans to stop.

This has been refuelling forever.

It will continue refuelling forever.

The KC-135 is so crucial

in keeping the Air Force flying

that planners foresee the Stratotanker

serving well into the middle of the century.

With that kind of longevity, it would join the U-2 spy plane

and the B-52 bomber in an amazing legacy,

flying for close to a hundred years.

It's not retired yet?

I mean this plane is old but it's not even the oldest one.

And there have been so many planes that have come and gone in our time.

This one just endures.

It's got old man strength.

That lowered 136.

We're on the ground now.

Still does what it does, and what it does is pretty awesome.

The U-2,

built by the CIA during the Cold War,

in a place that didn't exist.

It still watches the world from the top of the world.

The U-2 is the world's greatest spy plane,

and it earns that title with one devastating weapon: altitude.

The most badass airplane in the world,

flies higher and longer than any other plane.

This is the Air Force's

premier high-altitude reconnaissance aircraft.

This goes where no one else can go

and sees what no one else can see.

Still shrouded in secrecy,

the U-2 works at the edge of space,

to see things others want to hide,

just as it has since the 1950s.

And it's still the most badass.

At over 7,000 kilograms,

the U-2 weighs only half as much as a fighter jet.

It soars on glider-style wings,

blasted by a lightweight engine at over 650 kilometres an hour,

more than 21 kilometres up into the stratosphere.

That's where it lives,

loaded with over 2,200 kilograms

of secret surveillance equipment.

This plane is irreplaceable.

It is the best for what we do high altitude.

Everything about the U-2

relates to altitude and getting as much of it as possible.

It's the sky's apex predator, and it hunts altitude.

The U-2 is a pretty strangely shaped plane

because it's actually wider than it is long,

and that's by design,

to give it the absolute maximum amount of lift.

When you're flying at 70,000 feet, you're dealing with air

that's so thin it's basically non-existent.

So, you need absolutely gigantic wings, otherwise,

you're just going to be falling out of the sky.

The 105-foot wing span, a thousand square foot of area -

that's bigger than most people's apartment.

The wings are so big, it relies

on some basic technology to get off the ground -

training wheels.

So, we're the pogo crew.

This is a pogo.

Basically, this is the training wheels for the jet's wings.

The jet has very long wings,

and it's gonna drag on the ground.

Fuel's in there, it's gonna drag to each side.

So, to prevent and minimize damage, we punch these in.

So, it's from here up, it's gonna insert into the aircraft,

into the jet, and then it's going to taxi along.

It's going to come back in through the taxiway,

and these are just going to act as training wheels.

They're going to guide the wings in, prevent them from scraping,

keep them off the ground.

As the wing bends, the pogo will also bend with it,

to keep weight basically evenly distributed.

You want to keep the jet from, you know, hitting the ground,

so these got to be bent, so they have a little bit

of spring to them, just like a pogo stick.

On take-off,

it's gonna release the pressure from the wing

into the pogo holding it on the ground.

As soon as it takes off,

they're gonna drop right out.

And when the U-2 lands,

the pogos have to be reinserted, so the wings don't get damaged

as they drag on the ground.

As the jet comes down,

one side's going to be heavy, one wing.

It's going to be on the ground, dragging.

So, we're going to show up,

put a pogo right into that wing to keep it upright.

And so, the other side is going to do the same.

And now, that's going to drag. So, go to the other side,

just pick it up, and you just got to use your force,

shove it right into the socket.

You'll hear a click, a punch, and it's firmly in there.

So, now, once you have both pogos in the sockets,

so one on each end of the wing,

aircraft is completely ready to taxi back.

We're all racked and stacked, so we're all good to go.

All this effort goes into supporting

the U-2's primary mission,

being the best spy plane in the world

for more than half a century.

The U-2 is equipped with surveillance tools,

so it can gather information anytime, anywhere.

This airplane is a perfect tool for that job.

It can carry a reconnaissance package.

The nose can be removed and replaced

with a multi-spectrum camera,

basically the mother of all digital cameras,

that can see in a broader range than we can.

This airplane is so adaptable because we can just

change it out and adapt it to whatever we need to do.

While most of what the U-2 carries

is not publicly discussed,

it is loaded with multiple imaging technologies.

Powerful sensors can be affixed to the wings and large pods,

or located in the nose of the jet to gather pictures,

communication signals and intelligence.

Collectively, these are the eyes and ears of the U-2.

It carries cutting-edge equipment,

but the U-2 is an icon of aviation,

with an important history.

Well, most people know the stories

of the U-2 flying over the Soviet Union,

flying over Cuba, back in the late '50s and early '60s.

In a fearful world on edge,

information was the difference between war and peace.

The U-2 was built to get that information.

The U-2 was originally created

by the CIA, in secret, as a spy plane, with the goal of flying

above enemy air defences and radar,

photographing military installations

and nuclear test sites.

By flying higher than any plane had ever flown,

it spied over enemy territory in the Cold War,

taking detailed photographs of military capabilities.

The U-2 has flown over basically every military hotspot.

It was originally designed to fly higher

than anti-aircraft artillery could reach.

Of course, every time you invent something,

the enemy invents something to counter it, right?

And so, we ended up with anti-aircraft missiles

and rockets that could reach those altitudes.

In the 1960s, the U-2 took photos

of missiles in Cuba, sparking the Cuban Missile Crisis.

The U-2 helped avoid nuclear war by getting evidence

that the missiles had been removed from the island.

If there's been a military crisis

or something unusual going on in the sky,

the U-2 has photographed it.

It still watches global trouble spots today,

gathering the intelligence needed to build a safer world.

Where the U-2 flies, nothing can be left to chance.

That's why the U-2 is checked by hand before every mission.

I start at the front.

I make sure that all the hardware is here,

and I'm checking to make sure there's no damage

or anything that may have hit the leading edge of our wing.

Check our flaps.

We fly at 70,000 feet.

We are paying close attention to detail because the pilots,

when they're flying that high,

they're putting their lives in our hands.

Everything needs to be in perfect operating order,

and we can continue on our mission.

The U-2 is built to survive at extreme altitude,

but people aren't.

So, an essential element has to be added

before the pilot takes off.

So, the LOX converter is our equipment inside the aircraft

to convert the liquid oxygen into gaseous oxygen,

so the pilot can get oxygen

up into the converter, so he can breathe while he's up flying.

So, while he's up there, he can't breathe the air

that's up there. There's not enough oxygen in the air

while he's at altitude.

So, we have two converters in the aircraft.

They will convert the liquid oxygen into gaseous oxygen,

so he can breathe it from his suit.

Have to wear the suit

to protect against the liquid oxygen.

It's insanely cold - negative 247 degrees Fahrenheit.

If you were to get it on your bare skin,

you'll get immediate frostbite.

You could lose fingertips with it.

If you were to have your whole hand dumped inside of it,

you could lose your whole hand.

That's where a specialized flight suit

becomes a key component of the U-2's equipment.

So, the suit keeps our pilot alive

by containing liveable atmosphere inside.

The altitude that he flies, he wouldn't be able to breathe

or survive for very long in that atmosphere,

so this is gonna give him his own atmosphere.

So, they're inflating it right now.

He's gonna get it up to about one-and-a-half psi.

We want to make sure that the suit will inflate

and hold the air at a certain level.

If there's a hole in the suit,

air is going to be constantly escaping,

and in the event of a catastrophic cabin failure,

your water will start to boiling off gas.

Your blood vessels would expand like a balloon

and your skin would try to contain it all.

So, you would actually swell up.

Your brain can't inflate.

It would be like an instant concussion

and everything would just melt, basically, and you would die.

So, getting the pilot suited up properly

is one of the most important tasks before each U-2 flight.

Pilot.

- Good morning, sir. - Good to see you.

- All right. - Good to see you.

Ready to fly.

Let's do this.

Honestly, it feels real good. All these suits are custom fit.

It's good to go.

What my overall objectives are for the flight

is usually kind of just mentally preparing,

just like an athlete does before a big game.

So, there is obviously a comfort layer that I'm wearing.

And then, there's several layers after that

that are designed not just for comfort, but just for safety.

Exposure from the sun,

we've got a lot of radiation up at altitude.

Locking you down, sir. Three, two, one.

Meanwhile, back inside the hangar,

a crew prepares to launch a U-2.

So, I'm doing a pre-launch inspection, essentially.

Just double-checking that all of our equipment is ready to go.

The smallest problem can be catastrophic

for these flights,

so every detail must be double-checked.

Making sure there's no active leaks anywhere,

making sure all panels are up, ready to go.

On!

Once they get the sign-off,

it's time to take this bird into the sky,

so the U2 can do its job.

Hurtling into the heavens

at over 4,500 metres per minute,

the U-2 reaches its working altitude

of 21,000 metres in just 12 minutes.

Flying the U-2, you're the king of the world.

You're flying at an altitude where you're higher

than everybody else in the whole world.

It's humbling because, when you look out at the horizon,

you see this thin band of bright blue,

and then, above that, almost black.

That thin band of bright blue that you're looking at

is 90% of the Earth's atmosphere,

and you're coasting along on top of that.

But with satellites

acting as permanent eyes in the sky,

why is the U-2 still on the job?

It's better than a satellite because the satellite

will travel around the world, and you can only get one shot

for a very limited amount of time.

With this, we can get multiple shots for a much longer time.

And the advantage that the U-2 has

is that it can loiter.

It can stay over a target area for a long time.

So, a U-2 can go up and orbit an area for hours.

Altitude also keeps the spy plane safe

by not having to fly

where the unarmed U-2 could be at risk of attack.

This is where we keep the warning receivers,

so that we know when somebody's looking at us.

Sometimes the target shoots back, right?

We're able to stand off and fly perhaps over international water

and still get a good look at what we need to see.

But working at the U-2's extreme altitude

takes extreme skill.

That's because it lives in a place

other aircraft try to avoid -

the coffin corner.

Every aircraft has a speed it cannot fly below

or else it'll fall out of the sky.

The thinner atmosphere at high altitude

means a place must fly faster to stay airborne.

But a plane also has a maximum speed that it cannot go past

or else it will break up in midair.

The place between a plane's stall speed

and its maximum speed is the coffin corner.

And near space, less than 15 kilometres per hour

separates the U-2's stall speed from its maximum speed.

So, its coffin corner is tiny.

Fly a touch too slow, the U-2 falls;

a touch too fast and it disintegrates.

Don't want to go over maximum speed.

We got to be conscious of stall speed.

As altitude goes up, stall speed increases.

Now, you're flying in a very, very tight regime.

That takes a lot of stamina,

a lot of attention.

Normally, you don't fly in coffin corner.

You stay away from coffin corner.

That airplane was made to operate in coffin corner.

And as if it doesn't take enough skill

just to fly the U-2,

it takes still more to touch down safely.

That's what makes it hard to land,

the fact that it has bicycle gear.

Bicycle gear means that the U-2

has one set of wheels in front of the other,

unlike regular planes that have them in tricycle formation

or in three spots on the plane,

which provides greater stability.

When building the U-2, designers realized

that the weight of a traditional landing gear

would cost 1,500 feet of altitude.

That's why it has to land the way it does,

to save weight and get higher.

Every little bit matters hen it comes to altitude.

But unorthodox landing gear

is only one of the challenges.

The huge wings that keep the U-2 near space

make it hard to handle near the ground.

Fortunately, there's always help during landing

from another U-2 pilot in a chase car.

We want to make sure all our landings are safe,

and that's the biggest, most important thing

that the chase car driver can do.

Because the U-2 is designed to fly so high,

its long wings trap air underneath it

and obscure the pilot's view of the ground.

They can't see the runway as easily as you could

in other planes,

and we do everything we can to back up the pilot,

get them down safe and sound.

They do this

by communicating with the pilot by radio,

letting them know about obstacles, speed,

and anything else needed to touch down safely.

From the outside, we're also telling them things

that are tough to perceive in the jet.

The small one-degree pitch change

or one-degree bank change at the wrong time

could lead to disaster. The U-2 is a great jet,

but down low, it's just a big boat when it comes to landings.

Another safe landing means this U-2 can continue

its decades-long mission.

Plans to replace the U-2 have been enacted several times,

but the other aircraft, both piloted and unpiloted,

that were supposed to replace it over the years

never made the grade.

So, the U-2 perseveres.

So, the reason the U-2 is still doing the job

is because it does the job better now than it ever has.

What would you do differently?

We've got the great big, long wing,

we've got the powerful motor.

This airplane has that cool old '60s style,

but it's got all kinds of new stuff.

This airplane's better than new.

Every time a U-2 lifts off,

a new chapter is written in the machine's legacy of altitude

at the edge of space.

2475.

This is a C-5 Super Galaxy.

Biggest plane in the Air Force. If there's any plane

I could bet my life on, it'd be the C-5.

The C-5 is unlike any other airplane to fly.

We can go anywhere, any place, any time.

This is a behemoth.

The C-5M Super Galaxy

moves the US military around the world.

It's a big mission, and it can only be accomplished

by the biggest airplane, with gargantuan wings

that harness the laws of physics, engines that eat air,

and wheels strong enough

to carry the largest aircraft in the Air Force.

We can haul about six helicopters in here,

two tanks, 36 pallets, which is pretty cool.

With the capacity for over 127,000 kilograms of cargo

in its vast interior.

I love the detail, how it sits on top.

It just kind of towers above

every other airlifter in the Air Force.

It's about 60 feet high.

If you get a chance to go up there,

it's a pretty incredible view.

The C-5 Super Galaxy

is the undisputed big haul champion.

It's 67 metres wide, 19 metres tall,

and 75 metres long.

It crushes any scale at 250,000 kilograms.

It combines the individual strengths

of all other Air Force lifters - speed, range,

and capacity - into one giant aircraft.

And it all starts with the wings.

Like everything else about the C-5, they're monstrous,

weighing over 40,000 kilograms -

big enough to lift just about anything.

Yeah, wingspan is about 222 feet wide.

It is a beast.

Right now, where we're standing,

you can see that this wing's actually sloped.

It's not exactly 90 degrees, but it's pretty close.

Whenever we're taking off and we're in flight

and cruise altitude, the wings are actually more like this to,

you know, help out with the lift.

But it's really cool that the C-5 does that because

its wings are so long and the plane is so heavy itself,

it needs to be able to adjust to the weight

and the demands that we're asking it to do.

What you see is wing flex with the C-5 Galaxy.

This is important to happen

because you don't want a very stiff wing.

As the C-5 accelerates,

it begins lifting off the ground.

But as that lift occurs,

the wings are designed to be flexible

against the wind that surrounds them.

So, instead of remaining rigid,

they deflect upward about three-and-a-half metres.

A rigid wing would put too much stress on the wing root,

where the wings join the fuselage.

But flexible wings can handle the massive stress

and keep the incredible weight of the C-5 in the air.

When an aircraft is carrying very heavy loads

on very flexible wings, like the C-5 does all the time,

really small aerodynamic changes

can cause a huge amount of stress

and performance impact on the wings.

But there's another huge factor involved

in getting the C-5 airborne.

To lift as much as the C-5 is capable of transporting,

you have to have massive forward power.

So, it's a combination of the aerodynamics

of the huge wings and amount of raw engine power

that gets it done.

It's all about power,

and each of the aircraft's four turbofan engines

has plenty of it.

Something this big stays in the air because of the crazy amount

of thrust these engines are producing.

It doesn't really feel any different than your airliner,

except that it's ginormous.

Individually, they weigh 4,472 kilograms,

are 408 centimetres long,

and 236 centimetres wide.

The C-5 relies on them to produce

23,000 kilograms of thrust each.

Thrust is the forward power produced by your engine

that moves your vehicle forward.

The heat we see blasting out of the jet engine

is evidence of the thrust.

A massive fan pulls air in

at the front of the engine.

Some goes to the engine's core, while the rest flows around it.

The air at the core is compressed

by rows of spinning blades.

Fuel mixes with the compressed air in the combustion chamber

and, with a spark, it ignites.

The hot, rushing fan spins through turbines,

creating energy that drives the fan and the compressor.

The leftover air rockets out the back,

as bypass air amplifies that thrust,

and together, they propel the C-5 into the sky.

Heavy hauling takes a toll.

Technicians work on the engine's ignition systems

to ensure they fire up for the C-5's next load.

The whole engine itself needs a lot of attention.

It takes way more maintenance hours than it does flight hours.

These jets require a lot of attention

and a lot of troubleshooting and fixing.

For every couple hours that it flies,

it's almost double the amount of time for maintenance.

So, a group of maintainers remove this slat due to damage

that regularly goes up there, held together by a couple bolts.

And our slats are used for aerodynamics.

We'll reinstall this

in 12 to 24 hours and have this jet back up in the air.

But emergencies don't book appointments.

That's why the skill

and knowledge of Air Force maintainers is critical.

The craziest thing I actually ran into

was with our engines flying over the ocean,

we had a fuel valve problem

and we had to safely shut down the engine.

We were running off of three engines in flight

and it was still completely safe and that just proves

how reliable and safe this older aircraft truly still is.

The C-5 takes extreme cargo up to 128,000 kilograms.

That's double what your average cargo jet can handle.

I'm a loadmaster on it. So, what I do is load the plane

and I get to fly with it, which is super awesome.

Its cargo hold is nearly

four metres high by six metres wide,

and 43 metres long,

creating a total interior space

of 962 cubic metres.

It's a warehouse with wings.

The landing gear also incorporates a kneeling system.

It's one of the keys that lets the C-5 take anything aboard.

Our kneeling system is based off of a kneel drive, a motor,

and then these ball screws. So, we are one of the only jets

in the Air Force that allows the capabilities to kneel.

The coolest thing about our aircraft

is that we can load through the front

by opening up the visor...

...and the forward ramp.

And we can also load through the back

by opening the aft doors and the aft ramp,

which can be done simultaneously.

Whether it be in truck bed in the back

and driving in the front.

We can be driving things on

and tying stuff down in the back at the same time.

All this is easier said than done.

To prepare for today's load,

Staff Sergeant Taylor Ringgenberg

preps the plane for loading.

Right now, I'm going to go remove

and stow the locking pins.

It's a long checklist just to open a door.

Now, I'm going to check the status of my door panel lights

and I'm gonna ensure all my lights come on.

Good to go, all the lights are on.

With all the prep A-okay,

she can start to open the bay door.

Scanner cargo,

are we clear to open up the aft door?

And now, the loading can finally begin.

The biggest thing that we have to look for

when we're uploading is the clearances,

as we load very big things. So, making sure that you're not

going to hit anything is one of the most important things

of our job.

We're there to supervise the on and offload

as much as we are to do it.

My main job is to make sure we don't overload the plane,

and in the eight years I've been doing it,

never let it happen to me.

Literally, everything flies on the C-5.

Probably the coolest thing

was the president's limo.

We got to move Secret Service with them.

So, we had about eight limos in the back of the C-5.

Another load-out means another take-off.

It's routine, but impressive.

When we're on the runway about to take off,

we push our throttles up right here.

Each engine producing 50,000 pounds of thrust.

You kind of pause a little bit.

You feel like a little bit sinking in your seat,

and then you're just flying.

Pilot, gear up.

-Coming up. - I do.

The C-5 uses the sum of its parts

to be the longest-distance military airlifter in the world.

It crosses oceans, with a 194,000-litre gas tank,

delivering around 10,000 kilometres of range,

and landing for one reason only -

because it has reached its destination.

It's pretty wild to land the C-5.

It doesn't feel like you have

an 800,000-pound aircraft behind you.

CO-PILOT: Clear to land, checklist complete. Thanks.

And then, you touch down and I kind of just have

a sigh of relief almost.

And when it lands, over 195,000 kilograms of force

hits the tarmac on 28 wheels.

But the C-5 can take it,

thanks to some of the world's toughest shock absorbers.

As soon as we're down, it's all in the gears.

So, these struts inside are hydraulic lead

and with nitrogen charge

that allow us to take that impact

from the airplane hitting the ground.

Nitrogen acts as a cushion for hydraulic fluid

inside the gears.

The immense energy of the landing impact

is converted to heat,

which diffuses through the gear structure.

When we look at the C-5, each of those tires has

an inflation pressure of 200 to 300 psi.

That's huge.

That's about ten times more than a regular car.

What does that mean? The higher the pressure inside the tire,

the more weight it can carry.

The tires,

they can caster and freewheel,

so our turns can be tighter as we're taxiing.

Castering allows a wheel to pivot

or swivel around a vertical axis,

giving it much greater manoeuvrability

for a plane that size.

I would say it's the strongest aircraft in the Air Force.

So, if there's any plane I could bet my life on, it'd be the C-5.

A huge load,

massive yet responsive wings, enormous engines,

together, they make the impossible possible.

The one and only C-5 Super Galaxy,

taking to the skies,

moving more than any other.