serves as the National Airborne
Operations Center for the president, secretary of defense and
Chiefs of Staff or JCS. In case of national emergency or
of ground command control centers, the aircraft provides a highly
survivable, command, control and communications center to direct U.S.
forces, execute emergency war orders and coordinate actions by civil
Air Combat Command is the Air Force single-resource manager for the
E-4B, and provides aircrew, maintenance, security and communications
support. E-4B operations are directed by the JCS and executed through
U.S. Strategic Command. USSTRATCOM also provides personnel for
airborne operations center.
The E-4B, a militarized version of the Boeing 747-200, is a
four-engine, swept-wing, long-range, high-altitude airplane capable of
being refueled in flight. Its larger size provides approximately triple
the floor space of the earlier EC-135 command post.
The main deck is divided into six functional areas: a command work
area, conference room, briefing room, an operations team work area, and
communications and rest areas. An E-4B crew may include up to 112
people, including a joint-service operations team, an ACC flight crew,
a maintenance and security component, a communications team and
The E-4B has electromagnetic pulse protection, an electrical system
designed to support advanced electronics and a wide variety of new
communications equipment. Other improvements include nuclear and
thermal effects shielding, acoustic control, an improved technical
control facility and an upgraded air-conditioning system for cooling
electrical components. An advanced satellite communications system
improves worldwide communications among strategic and tactical
satellite systems and the airborne operations center.
To provide direct support to the president, secretary of
the JCS, at least one E-4B is always on alert at one of many selected
bases throughout the world.
The E-4B evolved from the E-4A, which had been in service since late
1974. The first B model was delivered to the Air Force in January 1980,
and by 1985 all aircraft were converted to B models. All E-4B are
assigned to the 55th Wing, Offutt Air Force Base, Neb.