The EC-135B version of the Stratotanker was designed from the beginning as an airborne command post. For nearly forty years one of these aircraft was airborne at all times to provide command and control of the United States’ nuclear forces in the event of a surprise attack. The primary external differences between these aircraft and the standard tankers are the large number of communications antennas along the top of the fuselage and the addition of a refueling receptacle above the cockpit.
In the mid-1960s this aircraft and two others were modified to EC-135J standards. Under the code name “Silver Dollar” they were assigned to Andrews AFB and were intended for use by the President as his airborne command post in the event of nuclear war.