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In this episode... It is bigger than any other airplane you've seen before.

It's overwhelming, really, in the scale of it.

The largest airplane ever constructed.

It's crazy.

Like, wow, we're really trying to make this thing fly.

And the pioneering historic innovations.

All right, so we're going to take this aircraft up into the sky and see what

it's capable of.

That made the impossible possible.

The Mojave Air and Spaceport in Southern California.

At this secretive facility, an aeronautical revolution is occurring.

Engineers are preparing to create history by flying a new aircraft for the

first time.

Designed to lift a 240 -ton payload to altitudes of over 29 ,000 feet,

this new airplane has the potential to radically transform the future of

aviation on Earth and in space.

But first, it has to leave the ground.

The original design intent for the carrier aircraft or mothership was to

half a million pounds, which to put in context is about two and a half, 737,

fully fueled.

It's more weight than has ever been lifted by an aircraft of this design.

To achieve this goal, they've had to redefine aeronautical engineering and

create an airplane unlike any other.

Stratolaunch. The Stratolaunch is in a league of its own in terms of airplanes.

When it comes to just sheer size, wingspan, engines, fuselages,

nothing can compare to Stratolaunch.

It is the world's largest wingspan airplane.

385 feet wingspan. That is roughly the size if you took a Saturn V rocket from

the Apollo days and laid it on its side.

That's roughly the length of our wing.

Standing over four stories high and with a wingspan wider than a Boeing 747,

Stratolaunch is the largest aircraft ever constructed.

It's powered by six gigantic engines, each producing over 50 ,000 pounds of

thrust.

Its mission? To carry rockets and prototype aircraft to altitudes of over

,000 feet before releasing them into the atmosphere or beyond.

But building the world's largest airplane presents some enormous

challenges for the team behind it.

For a start, how do you ensure it's actually going to get off the ground?

So it is a big challenge to make an airplane this large and light enough to

sure it can do the job.

Then once airborne, how does a three -man crew maneuver something as wide as

football field is long?

The airplane's far too large for a human to be able to move the control surfaces

while it's flying.

And how do you launch a payload into space?

Carrying a half -million -pound payload to altitude is a huge challenge.

Nobody's ever done it like this before.

Today will be the most significant moment in Stratolaunch's history.

After six years of design and construction and months of taxi testing

runway, pilot Evan Thomas is leading the three -man crew about to take this

gigantic aircraft into the sky for the very first time.

It's a little daunting as a pilot. It is unusual, and it's hard to compare it

to, in your mind, to something else.

that you've flown before, because really there's nothing like it in the world.

With the eyes of the aviation world watching,

failure is not an option.

Building an aircraft of this scale requires that our design and build teams

incredible attention to detail.

And it's not just the team's reputation on the line.

We are putting three human beings in the aircraft, and they need to come home

and land safely.

It's a mission no one takes lightly.

Even today, I walk in and I'm amazed by the size of it.

The design capability of being able to carry 500 ,000 pounds, that's...

roughly equivalent to two and a half fully loaded 737s. It is a huge amount

weight, and it is an order of magnitude above what any other airplane can do.

Lifting this much weight means that every part of Stratolaunch's airframe

to be supersized, including its elevator control surfaces, the devices that

enable the airplane to ascend and descend.

By tilting the elevator up, the pilot changes the airflow over the wing and

tail, causing the plane to climb and vice versa.

In order to make the airplane pitch to climb or dive, we need enough control

surface that that will change the aerodynamics over the tail and move the

tail, which then moves the rest of the airplane.

Measuring 29 by 6 feet, the four elevators are the largest control

Stratolodge.

Our elevators are larger than you will find on most conventional aircraft

because of the weight and the size of the airplane that we need to move.

But these supersized surfaces present a challenge in flight.

The force of the air moving past them is too great for crew to manipulate the

elevators by muscle power alone.

So, can the solution to this unique challenge be found with the great

of the past?

At the Evergreen Aviation and Space Museum in Oregon.

Pilot Mary Hsu is uncovering an airplane with a control system on a scale unlike

any other.

This is the Hughes H -4 Hercules.

Oh my gosh, the size of this is just incredible.

For over 70 years, it was the largest aircraft ever built.

It's hard to believe that this airplane would fly.

It almost brings a tear to my eye just to look at it.

Standing the height of an eight -story building and weighing in at a whopping

250 ,000 pounds, the H -4's wings are so wide that the Statue of Liberty could

lie across them.

The brainchild of pilot, philanthropist, and film producer Howard Hughes.

Due to wartime shortages of metal, the H -4 was built almost entirely from wood,

a fact that earned it the nickname the Spruce Goose.

According to Howard Hughes' notes, this airplane was designed to carry 152

,000 pounds of load. And to put that into perspective, up until that time,

one of the big airplanes was considered to be the DC -3.

It would carry about 6 ,000 pounds. So no wonder people thought Howard Hughes

was crazy.

Weighing almost 400 ,000 pounds fully loaded, it required engineers to think

bigger than ever before.

But much like the team behind Stratolaunch, Hughes encountered

challenges as he designed his record -breaking aircraft.

Oh my gosh, I'm going to sit where Howard Hughes sat.

Isn't that amazing?

Wow. Until the H -4, airplanes were controlled by a series of cables

to the pilot's control column.

Due to the sheer size of this airplane, conventional controls could not possibly

work. So Hughes and his engineers had to come up with a new plan and develop the

oil hydraulic pressure system.

As the pilot inputs a movement in the cockpit, Cables signal pumps to direct

hydraulic pressure to the relevant control surfaces disrupting the airflow

them and changing the direction of the plane.

This means that for each pound of pressure exerted on the controls, 1 ,500

pounds of pressure is directed to move the relevant surface.

These flight controls are very exciting because this is the first pressurized

system for boosting those controls, which allow an airplane of this size to

flown. Now, smaller airplanes don't need that. We can use the cables. But this,

because it's so huge, it would take the force of 200 men to be able to fly this

airplane.

Although it was completed after the war ended, the Goose did fly.

On November 2, 1947, observers witnessed Hughes take to the skies.

It only flew for one mile at an altitude of 69 feet, but it was enough to change

aviation forever.

Hughes proved that big airplanes can fly, and it paved the way for all the

airplanes of the future.

And with Stratolaunch now poised to become the largest plane in history, the

engineers behind it must look to Hughes' design to help them reach the sky.

In Southern California, A monumental flying machine is preparing to take to

skies for the very first time.

The Stratolaunch carrier aircraft.

With a colossal wingspan of 385 feet and six engines,

Stratolaunch is now the world's largest aircraft by wingspan, a record

previously held by the H -4 for over 70 years.

I would like to think we are following on in the legacy of the engineering team

and the builders of the H -4.

And the principles behind Hughes' pioneering control method are exactly

Evan and his team will need to get this 21st century behemoth airborne.

The StratLaunch has control surfaces that are hydraulically powered, but

mechanically signaled, which means we have cables running from the yoke up in

the front cockpit.

all the way to all the different control surfaces.

We said, well, rather than have a bunch of computers that would control the

hydraulic system and display that information to the pilots like it's done

modern airliner, we'd go back to the old 747 or Hercules H -4 days.

Despite the difference in design, some things remain the same even 70 years

later.

To get an airplane this size into the sky still primarily requires two things,

lift and thrust.

It's the world's largest wingspan. Even the biggest 747 or Airbus, their wing

stretches from our outer engine to the other outer engine. And we've got

60 or 70 feet of wing on either end of that.

So truly in terms of wingspan, this is something.

that no one else matches.

Eclipsing the Spruce Goose by over 65 feet, Stratolaunch also dwarfs its

predecessor in terms of power.

We can see the three engines here on the left wing. There are another three out

on the right side.

Those are Pratt & Whitney 4056 engines. They each produce 56 ,000 pounds of

thrust.

With a wingspan longer than a football field and six massive jet engines

producing more thrust than ten fighter jets,

Stratolaunch is poised to become the largest aircraft ever to take to the

It's a new milestone in aviation engineering.

But the team still faces many obstacles.

No airplane has been ever designed before to carry this large of a payload

this configuration.

Adding a payload will make Stratolaunch one of the heaviest aircraft in the

world, a fact that presents many challenges for senior design engineer

Wang.

Designing an airplane around that one large payload is really difficult. If it

were a lot of smaller payloads split up, that would be a lot easier.

But just this one massive, massive payload, that's a big deal.

Lifting a payload this large in this configuration is a challenge never

faced by aircraft designers.

Some other examples of airplanes that have carried big payloads are the

An -225 that carried a payload just under 500 ,000 pounds.

The modified 747s that were created to carry the space shuttle.

But cargo aircraft like the Antonov 225 have the luxury of storing their payload

inside the plane.

And although the NASA -modified 747 transported their vehicles outside the

aircraft, the space shuttle weighs roughly 165 ,000 pounds. Just a third of

weight Stratolaunch will transport.

The challenges of carrying one...

Half -million -pound enormous payload in one spot are that you have really high

point loads.

It's also really bad for the bending moment of your wing, and it's just a

massive spatial problem.

To ensure Stratolaunch is capable of carrying the record -breaking payload,

Grace and the team must find an airframe design capable of taking the strain.

For inspiration, they must look to engineering breakthroughs of the past.

Test pilot instructor Andy Edgell has come to the Valiant Air Command Warbird

Museum in Florida to uncover the engineering solution to one of World War

most difficult problems.

This is the XP -82 Twin Mustang.

Based on the original Mustang design, as we can see, it is two Mustangs strapped

together.

Over seven decades after its inception in the early 1940s, the XP -82

still remains one of the most unusual aircraft ever constructed.

She immediately reeks powerful.

She immediately reeks damaging.

She's an absolute beast of an aircraft.

The brainchild of American engineer Edgar Schmood, the XP -82 was designed

escort fighter that could carry enough fuel to travel thousands of miles on

-range missions over the Pacific Ocean.

Now, the way the twin Mustang solved this problem was it's got an extended

fuselage just after the cockpit. It was extended by about five feet. And that

freed up space to put more fuel into the fuselage section.

And remember, there's not just one fuselage on this aircraft.

There are two fuselages. So already we're getting more fuel in the aircraft.

Additionally, they filled the wings full of fuel and were able to put...

at least two drop tanks under each wing. And a drop tank is an external fuel

tank. And once you've used up the fuel, you can jettison or drop the fuel tank.

But with the wings carrying additional fuel tanks, there was no room for the

machine guns that the original P -51 Mustang had installed to defend its

against enemy fighters.

An alternative solution was required.

So the beauty of the twin -fuselage design aircraft is that it offers

versatility. Somehow you've got to strap the fuselages together, and they use

this centre wing section here.

Now, this is an aerodynamic surface. It helps the aircraft fly. But in addition,

it affords the engineers and the designers some extra space to put stuff.

Now, here you can see they've decided to put six 50 -cal machine guns.

Additionally, on this hard point here, they could hang an enormous 400

-gallon... fuel tank to extend the range even further.

With onboard fuel and drop tanks combined, the XP -82 could fly distances

over 2 ,400 miles, far outstripping a conventional P -51 Mustang.

But the twin fuselage design was useful for more than just increasing fuel

capacity.

To demonstrate, Andy and pilot Ray Fowler are taking to the skies.

I've checked for everything.

I think they've got enough runaway. You ready to do this? I'm ready.

All right, let's do this.

Although World War II ended before the XP -82 went into full production, it was

eventually reclassified as the F -82, and it saw service all the way up to the

Korean War.

Today, this is the only one in the world still flying.

Back in California, engineers have taken the unique concept behind the XP -82's

twin fuselage and supersized it.

In the Mojave Desert, senior design engineer Grace Wang takes a rare moment

appreciate the mind -blowing scale of the unique Stratolaunch project.

I love actually getting on the airplane and getting your hands dirty. A lot of

engineering companies, you don't get to do that.

You don't see very many twin fuselage airplanes, and that's because the

of most airplanes doesn't drive them to this design.

So in our case, the mission happened to drive us to this corner.

The payload goes underneath the center wing here.

There's five attached points, and the max load that one single one of these

points will take is over 600 ,000 pounds.

And that's crazy. That's about the weight of a 777 just taken at one place.

Measuring 240 feet from nose to tail and situated 105 feet apart,

Stratolaunch's twin fuselages are unparalleled in aviation history.

The fuselages are spaced apart how they are for a really big centerline payload.

provide clearance on the side for separation dynamics.

But it's really nice in that it actually gives you some flexibility for smaller

payloads. So instead of one large payload, you could put maybe three

ones in between these fuselages.

When I look at this twin fuselage design, part of me as an engineer

okay, this makes sense. And another part of the aviation fan in me just thinks,

hey, this looks really cool.

The twin fuselage may be the perfect airframe design, but it also creates

another problem that must be overcome.

We are here at the wing and fuselage intersection.

We call this the wing to fuselage joint.

There was a lot of effort put into this wing, so obviously it

had to carry enormous load, in particular bending moments.

Measuring almost 330 feet long,

Stratolaunch's wings are placed under immense strain.

This is most prevalent in the center.

The weight of the payload, combined with the lift generated in flight, creates

what's known as a bending moment, a force that's trying to snap the plane in

half.

So the amount of bending moment at the center of that wing, it's hard to count

millions of hundreds, but we did, and it is 800.

million inch pounds and you're like well what does that mean so we put it in

terms of elephants so that moment is the same as if you had put an elephant an

african elephant the big ones at on a ruler a mile away so that's a bending

moment that the center of that wing has to take one elephant mile to overcome

this vast force The wing is constructed around four massive continuous bars that

run from one end to the other without stopping inside the fuselages.

These bars are massive. They weigh about 16 ,000 pounds each.

And I think that is the largest single airplane component

ever made.

But being so massive means that when something goes wrong inside the wing,

there's only one way to fix it.

We need to go up in the wing routinely to repair parts or to fabricate parts.

There's a lot of systems, flight control cables up in here and hydraulics.

A lot of people have to spend a lot of time up here in these tiny bays.

It's hard to get a sense of...

the scale of this airplane, but when you disappear into this hole, it kind of

gives you a sense of how massive this airplane is and how much work it was to

put together.

Stratolaunch is a milestone of engineering.

But to ensure it's capable of dealing with the extreme forces of flight,

engineers must overcome another complex challenge.

To find a design that worked, we had to create something new because there's Not

much precedent for anything like this. We were really starting from scratch.

And draw inspiration from the great innovators of the past.

Oh, I cannot wait to see this thing.

Oh, wow.

The Stratolaunch carrier aircraft has redefined aviation.

100 miles of wiring, 28 wheels, and 6 engines have gone into creating

an airplane of gigantic proportions.

If it can get off the ground safely, it will become the largest plane ever to

take to the sky.

But before that can happen, The team must ensure that the airframe is strong

enough to cope with the forces of flight, yet light enough to get off the

ground.

When you're building an airplane, weight is central.

Weight doesn't help.

The whole lift equals weight equation, every pound that you can pull out of an

airplane helps.

This airplane also has to be really strong.

To support that elephant mile bending moment, also all the other plethora of

loads that it's experiencing, the structure has to be incredibly strong.

Strength and saving weight aren't really compatible in engineering usually. When

you want to make something strong, you usually make it out of better material

you throw material at it. You make it bigger, you make it wider, you make it

thicker. So saving weight and being strong are kind of...

Two opposite objectives.

So, could the perfect strong yet lightweight material be found in the

innovations of the past?

On the edge of Dallas, Texas, is a

groundbreaking piece of aviation engineering that could offer the

the team at Stratolaunch.

Oh, I cannot wait to see this thing.

Oh, there it is.

Oh, wow.

It's the Beechcraft Starship.

What a unique looking aircraft.

Engineer Dan Dickrell has come to discover its secret.

Look at the design of it. It's got two massive engines in the back. Those wings

that come out with the vertical wingtips, the swooping nose, the front

-facing wing.

This thing looks like nothing else. The shape of the Beechcraft Starship,

however, is not the game -changing aspect of it. When it was built in the

something else entirely that really, really changed the game.

The Starship was built to be the blueprint for the next generation of

aircraft.

So historically, airplanes were made of wood and fabric.

Later on, materials like steel and aluminum were used. These were much

but also actually ended up being much heavier.

Now when it came to the Starship, Rutan needed a solution that was just as

strong as metal, but also a lot lighter.

By saving weight.

Rutin could make the Starship more fuel -efficient, setting his design apart

from the competition.

His solution was to use a material that was relatively untested in aviation at

the time, carbon fiber.

It was a choice that would create a revolutionary aircraft.

All right, so we're going to take this aircraft up into the sky and see what

it's capable of.

Raj Narayanan is the proud owner of this piece of aviation history.

You can tell

you're in a composite airplane because it doesn't behave like a metal

airplane with the way the composite structure, the stiffness of the

structure.

Most other airplanes built at the same time that were metal airplanes are not

flying anymore because of corrosion and fatigue.

and reliability.

The Starship was a truly game -changing aircraft.

Its unconventional design inspired other mass -produced carbon fiber planes,

starting a trend in composite materials that would change aviation engineering

forever.

Back in California,

Stratolaunch manufacturer Scaled Composites have taken the use of carbon

in aviation to another level.

Stratolaunch is set to become the biggest aircraft to ever fly and to

safely gets off the ground.

The team has turned to a lightweight but strong composite material, carbon

fiber.

David Eicher is their director of engineering.

Strata Launch is the largest carbon fiber airplane in the world. The

the cabin, the tails, the control surfaces, the flaps, the ailerons, and

wing structure is all carbon fiber.

This means that without a payload attached,

Stratolaunch weighs just 250 tons, about 375 tons less than a fully loaded

Airbus A380.

But for David and the team, carbon fiber does more than just save weight.

This piece, it's very lightweight. You can see it's very thin. It's extremely

strong. So this piece maybe weighs a couple pounds at most, and I can easily

stand on it.

So I'm about 230 pounds. I'm standing on this piece that's just the skin and the

ribs that are holding me up.

Despite the cutting -edge nature of carbon fiber, molding it into a section

airplane still requires work to be done by hand.

I'm going to make a fuselage skin panel. This is a way to make a really strong

panel but very lightweight.

This is uncured carbon fiber.

David starts by layering sheets of carbon fiber on top of one another at 45

-degree angles to give the piece strength in multiple directions.

Next, he vacuum seals the part, bonding the layers together, before a

lightweight honeycomb core material is added to provide stiffness and strength.

David then adds the final layers of carbon fiber sheet, before giving it a

airtight compress.

So we're going to take the whole thing, including the sheet at the bottom that's

acting as our mold, and we're going to stick it in the oven and bake it.

This baking process allows the epoxy to cure, joining the layers of carbon fiber

into one solid part.

All right, so we've taken the part out of the oven and cleaned up the side,

trimmed it to the...

size it needs to be. And this is what the final part looks like here. You can

see a nice smooth surface.

And then here's the core. You can see the thickness that's been added.

You can't tell the difference between the different layers unless you

use a microscope.

So it's all bonded very tightly together. It's extremely stiff and

strong. I could try to snap it, but I'm not going to be able to break it off

like that.

It's a material that has revolutionized aviation.

and made Stratolaunch a reality.

But now the time has come for the team to get this gigantic aircraft into the

sky for the very first time.

If they are successful, they will pass into the realms of aviation legend.

Three crew members.

Six engines.

Two fuselages.

The largest wing ever built.

After six years of design, engineering, and construction, it all comes down to

this moment.

Dude, get out of here.

We put the power up and pull back on the column.

It's like an elevator ride going up.

Going up on 150.

The size of the aircraft does change the way we fly. We do things slow to get

there faster, do gentle turns, no high bank maneuvers, no high G maneuvers.

It is all slow and steady, wind at the rate.

Flying this airplane is not like piloting a racing yacht.

It's more like a supertanker.

It's going the direction it is going.

And in order to change that direction, you have to think ahead.

After 149 minutes in the air,

Evan and the crew line straddle launch up for the most nerve -wracking moment

the flight.

Now imagine I'm taking my supertanker at speed into the Panama Canal.

You really have to do your lineup very carefully and then keep the ship as

straight as possible coming into that target.

For me, as the pilot, I'm most concerned about will we be able to land it

safely.

That's the riskiest part of our first flight. What's going to happen when we

touch down?

Because we have to line up on the right side of the runway.

You know the left fuselage is over there somewhere, but you don't know exactly

where it is. It's very hard to imagine where it is.

We only have 43 feet to either side before we're taking part of the airplane

of the runway. So it's quite a small window.

to fly this giant airplane into.

This difficult landing is all that stands between the Stratolaunch and its

in the history books as the largest aircraft to ever fly.

Having successfully taken off and cruised the skies for over two hours,

Stratolaunch is preparing for the most difficult part of its maiden flight, the

landing. There is almost no margin for error.

500 feet, looking good, we're stable, we're on our line. 200

feet, still stable, still on our line.

Touchdown. We straighten the plane out on the runway, brake to a stop.

For me personally, a highlight of my career of flying.

Without a doubt.

Stratolaunch has done it. The team has solidified their place in aviation

history.

The world's largest aircraft, fully loaded, it weighs more than six blue

has a wingspan the length of 24 family cars, produces more thrust than 10

fighter jets, and can lift a 240 -ton payload to altitudes of over 29 ,000

Having gotten Stratolaunch airborne, the team has reached an aviation milestone.

Growing up, I did not have this concept of size, let alone this concept of size

for a flying machine in my head. This is an incredible accomplishment.

Stratolaunch is one of the most ambitious projects in the last two

aviation.

The courage and naivete that it took.

Whatever combination of that there was, and just a pure nerve to say, hey, we've

never made anything this scale before, but we're going to do it. That just

blows my mind.

It's a feat of engineering few thought possible.

I've been working on straddle launch for...

Seven years now, and it's a bit like my baby in designing it, seeing it come to

fruition, and seeing it fly.

By looking to great pioneers of the past for inspiration,

adapting their ideas, refining their

designs, and overcoming monumental challenges,

I never thought that I would work on an airplane this size or of this complexity

or this groundbreaking.

Working on this airplane was kind of like winning the aerospace job lottery.

Engineers have built an age -defining airplane and succeeded in making

the impossible possible.

I think that in 40 to 50 years, when we look at aviation milestones, this will

stand out as one of those milestones.

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