The Assassin (Sha ren zhe Tang Zhan)

The Airlander 10, the world's largest aircraft.

Engineers have taken some of the best elements

from helicopters, aircraft,

and, of course, airships

and wrapped them together in something

that could be a complete game-changer.

To take aviation to new heights...

What we're hoping to show with this aircraft

is that we can move to a whole 'nother level of performance.

...engineers had to look to the pioneers of the past...

Whoo-hoo! This is so cool!

I love it! Wow!

...to make the impossible possible.

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since the birth of aviation,

aerospace engineers have been creating aircraft

that have pushed the boundaries

to access as many places as possible across the planet.

But there are some locations and operations

that aircraft have yet to conquer.

One of the things we really want to be able to do

would be some fairly niche operations

that no other aircraft in the world could do...

Things like long-range disaster relief

or search and rescue.

For test pilot Simon Davies,

accessing the world's most remote regions

requires aircraft that can fly for days

and land anywhere.

For those sort of operations, you want something

that behaves a bit like a helicopter...

That can land, take off, offload cargo, or refuel

without any fixed infrastructure.

You what something that's like a helicopter,

but that can go further.

Engineering journalist Justin Cunningham

is at a former military air base in Bedfordshire, England,

to investigate an altogether new breed of aircraft.

This is Cardington airfield, home to a set of aircraft

that we thought have been all but extinct,

consigned to the history books.

But a group of engineers here want to change all that

with this...

...the Airlander 10.

This mammoth engineering marvel

is the largest aircraft in the world.

Its design is an aeronautical masterpiece.

Airlander 10 is actually a hybrid aircraft,

which means it combines elements of being a helicopter...

...a normal aeroplane...

...and also, the obvious one being an airship.

At a massive 300 feet long and 140 feet wide,

it's the size of a football field.

Using fixed-wing helicopter and lighter-than-air technology,

Airlander 10 dwarfs everything in the skies.

With a 1.3 million-cubic-foot frameless material hull

and hypersensitive pressure control,

this hybrid aircraft can stay airborne,

fully crewed, for five full days.

Four fixed and rotational turbo-charged diesel engines

propel and maneuver the craft in any direction,

and a cargo hold beneath the hull

has enough capacity for an 11-ton payload.

And its inflatable skids

allow the vessel to land anywhere, even water.

It's not like anything else anybody's done in aerospace

for 50 or 60 years.

Airlander's structure is completely unique,

and building it posed colossal engineering challenges,

particularly in inflating the gigantic hull.

The inflation of the hull is absolutely critical

to the structural integrity of the aircraft.

To fly safely,

the gas inside the Airlander's frameless hull

must not only maintain the ship's structure

and provide buoyancy,

but it must also be non-flammable.

But achieving this would've been impossible

without the chance discovery of helium.

In 1617, father Francesco Lana de Terzi

came up with an invention

that rightly served the title of "airship."

Hee-hee!

But his dream never became a reality.

Ohh...

In 18th century France, the Montgolfier brothers

noticed how their washing bellowed

when it was drying over a fire.

Ooh!

And in 1793, they launched the first human-made flight

with living passengers...

A sheep called Montauciel... A duck...

And a rooster.

Cock-a-doodle...

But when they tried it with humans,

the dangers of a midair bonfire became apparent.

Zut alors!

That same year, fellow French brothers the Roberts

launched the first manned hydrogen-gas filled balloon.

Nah, nah, nah-nah, nah!

Hydrogen balloons and blimps became all the rage,

but their flammability meant they were always vulnerable.

Uh-oh.

Fortunately, a solution wasn't far away.

Aah!

Mechanical engineer Dan Dickrell is in Kansas

to find out how the accidental discovery of helium

on America's great plains changed airship safety forever.

The problem with early airships

is they were filled with hydrogen.

Here, I have some hydrogen.

What I'm going to do is introduce this hydrogen gas

into a solution of soapy water.

As the gas comes out, it creates bubbles.

These bubbles will be filled with hydrogen.

Now if I free these bubbles from its container,

we see... ah... they float away,

which is great for airships.

But there's one significant problem... fire.

This time, we're going to introduce a source of flame.

And let's watch what happens.

Here we go.

Whew! all right.

Hydrogen is very flammable.

However, in 1903, the tiny town of Dexter, Kansas,

unintentionally stumbled upon a solution.

The 19th century had seen an economic boom

in the mining of flammable gas

for lighting, heating, and cooking.

And speculative drilling had hit a source of a new gas

that spewed out millions of cubic feet

of the stuff each day.

The town thought it had a potential fortune on hand.

The people of Dexter,

they were planning to celebrate the discovery

with an elaborate "lighting of the well" ceremony.

The thought was a pillar of flame would rise up

and light the sky for miles around.

But when the time came to ignite the well...

The gas just wouldn't burn.

Samples of this mysterious non-flammable gas

came to chemistry professors Hamilton P. Cady

and David Mcfarland.

At the university of Kansas,

they made an astonishing discovery.

They concluded that the mystery gas was about 2% helium,

a substance which had been thought

to only exist on the sun.

Not only that, in fact, further research concluded

that helium here on earth underneath the great plains

existed in almost unlimited quantities.

And during world war I, when the U.S. government

replaced the highly-flammable hydrogen for its airships

with a non-flammable gas,

helium finally took off, and for good reason.

As the people of Dexter found so many years ago,

helium... It just won't burn.

Both buoyant and non-flammable,

the military declared helium a critical war material,

and this made safe airship travel possible.

Today, the helium that lies under my feet here

in the great plains is used in everything,

from nuclear reactors to laser beams.

If not for that chance discovery in a tiny Kansas town

so long ago, the world that we know today

might be a very different place.

Airlander's engineers have used

a staggering 1.34 million cubic feet of this breakthrough gas...

...helium,

to inflate the world's biggest aircraft.

Despite being filled with helium,

its net weight is around a ton,

something like the size of a small car.

And the reason they have done that

is they get this maneuverability and stability

that you just wouldn't get otherwise.

And it also means they only need to provide about a ton of thrust

to get this thing airborne.

The helium maintains the aircraft's shape

and creates buoyancy,

and drawing on fixed-wing aircraft designs,

the Airlander's unique elliptical hull

acts as an air foil,

which creates 40% of Airlander's lift.

We're demonstrating that,

by using lighter-than-air technology,

mixing it with other technologies,

we can move to a whole 'nother level of efficiency.

This aircraft is going to show capabilities

that no other aircraft have got.

Airlander 10 is pushing the boundaries

of aeronautical technology,

but for this aircraft to join the greats of aviation history,

its engineers had to face many more challenges...

Just look at this place.

This is somewhere where history truly was made.

This is hangar "Y."

...to produce more impossible engineering.

The hybrid airship Airlander 10 is the world's largest aircraft.

Built for endurance, this 300-foot-long megaship