The US boasts four E-4B Nightwatch planes that follow Donald Trump when he flies across the world.
Incredible footage captured on board one of the jets provides a glimpse into the aircraft – dubbed “the flying Pentagon” – which comes into use in case of a nuclear or terrorist attack, or in the event of war being declared on the US.
The modified Boeing 747 fleet – known as the National Airborne Operations Centre – is kitted out with specialist equipment and travels with dedicated teams of military strategists, analysts and communication aides on board.
Whenever Air Force One takes to the skies, E-4Bs follow ready to act as a command centre for Mr Trump, the US Defence Secretary and Joint Chiefs of Staff, in the event of war.
A presidential trip usually involves hundreds of military and government personnel and often requires dozens of flights, including a backup for Air Force One and transport planes that move the motorcade, helicopters and communications gear.
Since the 1960s, the US has been building and equipping the special set of planes whose sole purpose has been to evacuate the president in the event of a nuclear war.
The jets have been in operation since the 1970s, and were first used during the Cold War, and have the capability to communicate with anyone from anywhere in the world.
Boasting a special five-mile trailing wire antenna, the jets allow the President to communicate the nuclear submarine fleet – even if ground communications are destroyed.
The Nightwatch planes are also designed to withstand an electromagnetic pulse sparked by a nuclear explosion, and contain top secret defence measures to protect themselves from an attack.
Operated by the First Airborne Command and Control Squadron of the 595th Command and Control Group, coordinated by the US Strategic Command, the jets are stationed near Omaha, Nebraska, at the Offutt Air Force Base.
In 2006, there was retiring the E-4B fleet in 2009 but when Robert Gates he ensured the fleet, dubbed “Air Force One when it counts” to remain fully operational.
At least one plane is kept running at all times, according to reports, to ensure the aircraft if ready to fly at a moments notice.
While the existence of the fleet is not a secret, they are barely mentioned, to the point that the US Air Force does not publicly acknowledge owning them.
In fact, the bigger secret is where they would fly the President should the day come.