Mission

     The E-4B is the National Emergency Airborne Command Post for 
the National Command Authorities. In case of national emergency or 
destruction of ground command control centers, the aircraft provides 
a modern, highly survivable, command, control and communications 
center to direct U.S. strategic forces, and execute emergency war 
orders by the National Command Authorities.

Features

     Air Combat Command is the Air Force single-resource manager 
for the E-4B.  ACC provides aircrew, maintenance, security and 
communications support. The Joint Staff controls E-4B operations 
and provides personnel for the airborne command 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 National 
Command Authorities work area, a conference room, a briefing 
room, an operations team work area, a communications-control area, 
and a technical-control and rest area. An E-4B crew may include up 
to 114 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 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 command post.
     To provide direct support to the National Command Authorities, 
at least one  E-4B with a fully manned battle staff is always on alert at 
one of many selected bases throughout the world.

Background 

     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. Conversion of three E-4 aircraft to B models was 
completed in March 1985.

General Characteristics

Primary Function: Airborne command post.
Builder: Boeing Aerospace Co.
Power Plant: Four General Electric CF6-50E2 turbofan engines.
Thrust: 52,500 pounds (23,625 kilograms) each engine.
Length: 231 feet, 4 inches (70.5 meters).
Wingspan: 195 feet, 8 inches (59.7 meters).
Height: 63 feet, 5 inches (19.3 meters).
Maximum Takeoff Weight: 800,000 pounds (360,000 kilograms).
Endurance: 12 hours (unrefueled).
Ceiling: Above 30,000 feet (9,091 meters).
Unit Cost: $258 million.
Crew: Up to 114.
Date Deployed: January 1980.
Inventory: Active force, four;  ANG, 0; Reserve, 0.

Point Of Contact:
Air Combat Command; Public Affairs Office; 90 Oak Street; Langley 
AFB, VA 23665-2191; DSN 574-5007, or (804) 764-5007.