The custom modifications include interior reconfiguration for presidential duties: sleeping quarters, office areas, two kitchens, a medical operating table and pharmacy, communications systems, telephones and television sets, even workout rooms. There is also space for the president's family, staff and news media. The plane can also be operated as a military command center in the event of an incident such as a nuclear attack. Operational modifications include in-flight refueling capability and anti-aircraft missile countermeasures.
Air Force One flights are handled as military operations with all flights managed by the Presidential Airlift Group of the Air Mobility Command's 89th Airlift Wing at Andrews AFB in Maryland. The President often flies a U.S. Marine Corps helicopter, callsign Marine One, between the Andrews AFB and the White House. Similarly, Army aircraft carrying the President bear the callsign Army One, and Navy aircraft are called Navy One. A civilian plane carrying the President gets the callsign Executive One, and a plane carrying a member of the first family will be called Executive One Foxtrot.
The callsigns were established for security purposes during the Dwight D. Eisenhower administration, after a commercial flight with the same callsign as a flight the President was on coincidentally entered the same airspace.
Both planes are only designated Air Force One while the President is onboard. In 1974, when Richard M. Nixon resigned the presidency and departed from Andrews AFB on Air Force One, it was arranged that the plane's callsign would switch from Air Force One to its SAM designation the moment Gerald Ford took the oath of office.
From its inception Air Force One has become a symbol of Presidential power and prestige, carrying the president on several diplomatic missions. It has also played a role in history. On November 22, 1963 SAM 26000 carried President John F. Kennedy to Dallas, Texas where he was assassinated. It was on the plane that Vice President Lyndon B. Johnson took the oath of office, and the plane carried Kennedy's remains back to Washington. SAM 26000 also carried president Nixon on his historic trip to mainland China.