The United States lifted the E-4B Nightwatch, known as the "ship of the day", reports RIA Novosti,. It is intended for members of the US supreme military leadership, including the president and defense minister, in the event of a nuclear war. It can be used as a command post in case the ground control structures are destroyed or damaged. Installed on board the E-4B Nightwatch equipment is protected from the damaging factors of a nuclear explosion. And the aircraft itself can be in flight for a week, subject to air refueling. According to the data published by the Flightradar portal, the aircraft is located above the state of Indiana. Information about the reason for which the aircraft took off in the air, yet.