The Boeing E4-B is an Air Force operated aircraft that evacuates government leaders and allows command of wartime operations in the event of nuclear war. The aircraft contains equipment that is protected from nuclear effects, hacking, and signal jamming. The E4-B can refuel in flight, fly at high altitudes, and carry 112 people.
The E4-A and E4-B are actually modified forms of the Boeing 747-200B. Development began when an airline did not complete an expected order for Boeing 747-200 aircraft. Two frames had already been built, that were no longer needed. Boeing offered the 747-200B frames to the United States Air Force. The idea was to use these frames to create an aircraft for replacement of the EC-135J (the previous National Emergency Airborne Command Post). The new aircraft offered more space and the ability to stay aloft longer than the EC-135J.
Boeing was awarded a contract February 1973 for two unequipped aircraft. Two aircraft were added later that year. The aircraft designation was E-4A. E-systems, part of Raytheon Intelligence Information and Services, received the equipment contract. In November 1973 program costs were estimated at $548 million for seven aircraft. This reflected six operational aircraft and one research and development aircraft.
Andrews Air Force Base in Maryland received the first completed aircraft December 1974, two more E4-As were delivered the next year. The fourth, and final, aircraft received more advanced equipment, a radome (which housed a SHF satellite antenna), and increased protection from an electromagnetic pulse that results from a nuclear blast. The upgraded aircraft received the designation E4-B. The three E4-A aircraft were retrofitted with the same equipment as the E4-B, and now fly under the E4-B designation.
There are four E4-B aircraft in the Air Force fleet. It is rare for all the aircraft to be operational at the same time due to maintenance schedules. The aircraft that travels with the President is referred to as the alert plane. The crew of the alert plane is on standby for a week at a time.
Communications are extensive on the E4-B. Nine different areas of the plane have been outfitted with different types of communications equipment, ensuring that those aboard can communicate with military forces. High frequency and Military Strategic and Tactical Relay (Milstar) communication systems are located in the aircraft hump, over the fuselage. The Milstar communications system is a constellation of geocentric orbit military satellites. The satellites provide a secure, jam-free signal that can reach ground stations, ships, submarines, and other aircraft.
The command/senior leader area has a video screen, desk, chairs, and a bunk. The conference room can host live video conferences and is predominately used for long meetings. The rest area includes bunks with curtains for the crew. The briefing room is equipped with a projector and hosts senior military leaders and traveling press. The operations/battle area has 27 work stations that can accommodate a maximum of 30 people. This area was created to assess the overall infrastructure of the US including power grid status. Radio compartments include equipment for receiving secure and non-secure transmissions. One console is dedicated to routing satellite, phone, and radio communications throughout the aircraft. A separate console routes air to ground transmissions. A very low frequency (VLF) trailing antenna can be trailed behind the plane.
Flight controls are analog to guard against electromagnetic pulse damage and hacking. The cockpit is very similar to that of a regular 747-200, other than the flight engineer panel. The generator panel houses controls for eight generators, two per engine. Navigation is located at the rear of the cockpit.
Length: 231 feet 4 inches
Wingspan: 195 feet 8 inches
Height: 63 feet 5 inches
Maximum takeoff weight: 800,000 pounds
Endurance: 12 hours
Crew: 112 maximum