Published March 15, 2005
The E-4B serves as the National Airborne Operations Center for the president, secretary of defense and the Joint Chiefs of Staff or JCS. In case of national emergency or destruction 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 authorities.
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 the 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 selected augmentees.
The E-4B has electromagnetic pulse protection, an electrical system designed to support advanced electronics and a wide variety of 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 defense and 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.
Primary Function: Airborne operations center
Contractor: Boeing Aerospace Co.
Power Plant: Four General Electric CF6-50E2 turbofan engines
Thrust: 52,500 pounds each engine
Wingspan: 195 feet, 8 inches (59.7 meters)
Length: 231 feet, 4 inches (70.5 meters)
Height: 63 feet, 5 inches (19.3 meters)
Weight: 460,000 pounds (208,652, kilograms)
Maximum Takeoff Weight: 800,000 pounds (360,000 kilograms)
Fuel Capacity: 340,000 pounds (154,221 kilograms)
Payload: communications gear permanently installed on aircraft
Speed: 602 miles per hour (523 knots)
Range: 6,200 nautical miles
Ceiling: Above 30,000 feet (9,091 meters)
Crew: Up to 112 (flight crew and mission crew)
Unit Cost: $223.2 million (fiscal 98 constant dollars)
Initial operating capability: January 1980
Inventory: Active force, 4; ANG, 0; Reserve, 0