Boeing E-4

The Boeing E-4 Advanced Airborne Command Post, with the project name "Nightwatch", is a strategic command and control military aircraft operated by the United States Air Force. The E-4 series was specially modified from the Boeing 747-200B. The E-4 serve as a survivable mobile command post for the National Command Authority, namely the President of the United States, the Secretary of Defense, and successors. The four E-4Bs are operated by the 1st Airborne Command and Control Squadron of the 55th Wing located at Offutt Air Force Base, near Omaha, Nebraska. An E-4B is denoted a "National Airborne Operations Center" when in action.