There is a plane that could signal impending doom if you spot it in the sky.

Luckily for us, there hasn’t been a need for these aircrafts to be used, but the US have four of these ready, in case the worst of the worst happens.

So, one day in the near future, if you see one of these zooming above your head, you might want to run – or don’t, and you’ll be wiped out within a few minutes anyway.

But by what, exactly?

Looks very intimidating, doesn’t it? (Jacquelyn Martin-Pool/Getty Images)

Basically, the US have a plan of action in case they find they find themselves in the midst of a nuclear war, which at times has been something that has come too close for comfort.

Now that Donald Trump has been given the ‘nuclear football’, a lot of people will be attentively watching with baited breath.

In case it does become a reality, they would need to get off the ground and establish a command and control centre, clear of any potential attack targets in a matter of minutes.

They have called it the National Airborne Operations Centre (NAOC), and they have prepared four E-4Bs, which when translated from tech-speak, are modified Boeing 747-200s that can be used for the military’s doomsday needs and communications.

They aren’t cheap to run, setting the military back $159,529 (£126,000) per hour to operate, as the Air Force’s most expensive plane.

They will be used to carry and protect the nation’s most senior military officials and key figures such as the President, who will be in charge during a nuclear crisis, or similar levels of emergency.

Meant to be ready at any given time, one of the planes has its engines operating 24 hours a day, seven days a week, ready to takeoff when needed.

Featuring advanced thermal and nuclear shielding, those inside will be protected from the impact of a nuclear blast.

On top of this, the Boeing doomsday plane can fly non-stop for an entire week once airborne, due to its refuelling capabilities, while being loaded with protective measures to stop missile attacks.

The E-4B is also used for transporting officials overseas (Fabrizio Gandolfo/SOPA Images/LightRocket via Getty Images)

If you step onboard, you’ll see a mobile command centre with ‘advanced radar and surveillance technology’, which can keep track of any potential threats in real time, boasting some of the highest levels of tech in the world.

These four aircraft are based at an Air Force Base that also happens to be home to the US Strategic Command, south of Omaha, Nebraska.

Seeing it in the sky shouldn’t necessarily cause a straight panic though, as the planes are also used to transport officials overseas for events and meetings.