There are four Boeing E-4B aircraft (there have been a handful of names but none easily memorable) flying by the USAF—of course, with the President aboard its call sign becomes Air Force One. They primarily exist as superb self contained communications aircraft from which U.S. can wage nuclear war but are useful in many other missions. The aircraft is equipped for communications with satellites to submarines and can be provisioned for two weeks and can refuel while aloft. At times one of the aircraft are assigned to missions to the Secretary of Defense when traveling abroad as well as to catastrophe emergencies.
An Air Force E-4B National Airborne Operations Center aircraft sitting at Bogata’s International Airport waiting for Secretary of Defense Robert M. Gates—U.S. Air Force photo by Tech Sgt Jerry Morrison
The E-4B’s primary mission is to be the National Airborne Operations Center and supports the president, the Secretary of Defense and the Chairman of the Joint Chiefs of Staff with an alert crew of 21 joint-service battle staff members along with the aircrafts flight as well as maintenance crew. The aircraft type passed a significant milestone by sitting alert constantly for more than 35 years—U.S. Air Force photo by Lance Cheung
An E-4B aircraft sitting on the ramp of Ninoy Aquino International Airport in Manila as Secretary of Defense Ash Carter and Philippine Secretary of National Defense Voltaire Gazmin return after touring the aircraft carrier USS John C. Stennis (CVN 74)—U.S. Air Force photo by Sr Master Sgt Adrian Cadiz