and all US military ground communication was destroyed,

this $223 million plane

would become the command and control center

for the US military's most senior officials.

This is the E-4B "Nightwatch."

It's basically a flying war room

designed to withstand a nuclear blast.

Ryan Pickrell: I like to think of the E-4B as kind of like

a flying backup Pentagon.

Potentially more secure than the Pentagon.

If you're seeing it at its maximum capability,

which hopefully we never do,

yeah, you're looking at an apocalyptic scenario,

which is why it's affectionately known as

the "doomsday plane."

Narrator: Four E-4Bs make up

the National Airborne Operations Center.

And the US Air Force is responsible

for the operation of all four of them

out of Offutt Air Force Base near Omaha, Nebraska.

The retrofitted Boeing 747s were made for war.

Originally designed in 1973, the E-4 series planes

were thought to be the best way

a president during the Cold War

might survive a nuclear explosion.

And since their inception, one of the doomsday planes

has stood on alert 24/7.

Edward Garcia: Because we're a 24/7 ops mission,

we are not a non-deployable unit due to our proximity

to the president and all other key assets at one time.

But, day to day, it is highly important

because we can assume the role of a primary command center,

much like the Pentagon is, much like strat-com can be.

We can assume that role in the air as well.

Narrator: In the immediate aftermath of a nuclear blast,

the president, the secretary of defense,

and the joint chiefs of staff

would all be safe aboard the E-4B.

From there, they could order nuclear strikes

or execute emergency war orders.

And while the majority of the E-4B's capabilities

are classified, we do know a few things.

The plane has three decks and can hold a crew

of up to 112 people.

With four massive engines, the E-4B can fly

for 12 hours straight without refueling,

though with aerial refueling capabilities

it could theoretically fly for several days.

It costs nearly $160,000 per hour to fly the E-4B,

making it the most expensive airplane

the Air Force operates.

And it's built to survive a nuclear blast.

To prevent radiation, the windows have a wired mesh,

similar to what you'd see on the window of a microwave.

Equipment and wiring on board are hardened

to survive an electromagnetic pulse.

There's also thermal and nuclear shielding

and direct-fire countermeasures.

Aboard the plane, space is broken down

to optimize war coordination.

At the front of the plane,

executive quarters house the senior military officials.

The upper rest has 18 bunks available

for the Air Force crew.

They work 24-hour, seven-day shifts and sleep on board.

Beneath that is the secure conference room,

where the joint chiefs, president,

and secretary of defense can give war orders.

The briefing room is where officials

can update the traveling press, or battle staff,

on strategy and coordination efforts.

In the center of the plane,

officers from every branch of the military

will hammer out a strategy in the event of a crisis.

This base is known as the battle-staff room.

And all outside communication happens

at the back of the aircraft

from the communication and technical control room.

From here, operators can communicate

with virtually anyone in the world,

in any situation.

Scott McCandless: It's designed that,

in the most austere environments,

during or after a nuclear war,

it survives and can communicate,

from the most cutting-edge communications technology

to old, antiquated communications technology.

We have the ability to endure and communicate

with fielded forces and the rest of the US government.

Narrator: That bubble on top of the E-4B

is where all the communication technology is held.

It's called the "ray dome," and an estimated

67 satellite dishes and antennas are kept here.

The E-4B has more communication capabilities

than Air Force One.

There's even a 5-mile-long "tail" that can be extended

behind the plane to allow for communication

with submarines that are underwater.

But even with all the fancy communication tech,

you'd be surprised at how old-school

the rest of the technology on board is.

There's no digital, and there's no touch screens.

Everything is analog. And that's on purpose.

That vintage vibe continues throughout the airplane.

Pickrell: The E-4B doesn't really have windows,

and it's actually really drab on the inside.

You're looking at kind of a beige color

that looks like it came straight out of the 1970s or '80s,

which it did.

Narrator: The doomsday plane's utilitarian nature is

completely intentional to keep the focus on the job at hand:

preparing for the worst.

But hopefully we'll never have to see

the doomsday plane at its full capacity.

During peacetime, the E-4B's main job is to transport

the secretary of defense on foreign trips,

and one always follows the president in Air Force One

on overseas visits.

Garcia: The mission is very tedious, it is, no kidding,

one of the most arduous things that you could possibly do,

but it's so rewarding in the sense of,

every day you know that you're doing something

or you're preparing for the worst.