Aircraft Factsheets

Boeing E-4

By Gostar den Daas | January 2014
The Doomsday plane

(Photo visual: Josh Plueger, Offut AFB, 17 June 2009)

The National Airborne Operations Center (NAOC), nicknamed "Doomsday plane" is an aerial command station designed to execute war orders when ground facilities are destroyed during a nuclear conflict. The system allows the president (in his role of commander-in-chief) and key members of his battle staff to maintain in command during such a situation.

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Mid 1960s operation ‘Nightwatch’ was initiated to provide an National Emergency Airborne Command Post (NEAP). An EC-135J variant, modified KC-135B, was developed to support this task of which three were build. Early 70s Boeing offered two Boeing 747-200s which were originally planed to be commercial airliners, as replacements for the EC-135Js. The USAF Electronic Systems Division awarded a contract in 1973 to supply two unequipped aircraft, designated E-4A. The A-model basically housed the same systems as the EC-135, but offered more space and could remain in the air for longer period of time.

A third aircraft was added July 1973. E-systems installed all internal equipment, and the first complete A model was handed over to Andrews AFB, December 1974. The third aircraft was fitted with General Electric GE-F103 engines instead of the standard P&W JT9Ds on the first two. Later the first two were also retrofitted with the GE engines.

63-8057 EC-135J

The B Model

December 1979 a fourth aircraft (75-0125) was added. This aircraft was fitted with the distinctive “Hump” on the back of the upper deck, housing the SHF antenna. It also offered upgraded accommodations, additional shielding, upgraded electronics and new CF-6-50E2 engines. This became known as the E-4B model.

The B models biggest structural change was the ability to survive an Electromagnetic Pulse (EMP) from a nuclear blast. Protection against radiation was also improved. This can best be seen on the windows, which have the same metal screens added like you see in a microwave.

By January 1985 all three remaining A models had been converted to B models.

Operational service

E-4B walk-through

17 minute video of an exclusive walk-through tour.

The E-4Bs flight crew is doubled for redundancy, and the aircraft has a special crew rest area. Besides the crew, the aircraft accommodates up to 94 crewmembers, including 30 battle staff members and the president in his role as Commander-in-Chief.

The upper deck includes a dated non-class cockpit with a three men crew, including a flight engineer as seen on the earlier 747 models. The cockpit was never upgraded, as the analog version is less susceptible against EMP. There is also an additional navigation station, not found on normal airliners. Located aft the flight deck is a lounge area and sleeping quarters for the flight crew.

The main deck (492 m2) is partitioned into five operating compartments. The forward entry area, with kitchen equipment and seats for stewards or guards, the NCA area (a flying equivalent of the White House Situation Room), a conference room, the main communication control AreaC3I and rest area with 14 bunks.

The lower deck, normally holding the passengers luggage or cargo, houses the power systems, transmitters and water tanks. The forward right site also includes a retractable airstair, to give easy entry access to the aircraft, without any additional support needed. The aft section contains a 5 mile (8 km) trailing wire antenna (TWA) reel and operators station. The TWA is used for communication with ballistic missile submarines.

One of the aircraft and its crew of 63 is always on 24-hour alert. The E-4 is also available to the Federal Emergency Management Agency (FEMA) to assist during a natural emergency. In the event the president travels outside the US, his VC-25 will always be accompanied by a E-4 which will be on standby at a nearby airport (within several hundred miles of the presidents location).

During a mission the aircraft can stay airborne for up to 72 hours (with in-flight refueling.) In was designed to be able to stay in the air for a full week!


Two variants were build, the A and B model. The three A models were converted to the B model and a forth B model was added.

E-4A, The characteristic bulge, which is on the B model, was absent. No visible communication equipment was present on top of the fuselage.

E-4B, CF-6-50E2 engines fitted, delivering 52,500 lb. of trust. Also electromagnetic pulse protection was introduced. Nuclear and thermal shielding enhanced. Advanced electronics were fitted and the communication systems were upgraded.

Updating the communication systems is an ongoing progress to cope with the ever-changing technology.

Specifications listed for the E-4B variant:

Measurements:Length: 70.51m (231 ft 4 in), Wingspan: 59.64m (195 ft 8 in), Height: 19.94m (63 ft 5 in).
Powerplant:4 General Electric F103-GE-100 turbofans, each rated at 233.53 kN (52.500 lb).
Fuel and load:150395 Kg (331.565 lb).
Speed:926 km/h (500 kts).
Range:12 hours (unrefueled), 72 hours with in-flight refuelling.
Crew and equipment:63 crew members. Advanced communication equipment including super high frequency system enabling direct TV/radio broadcasts over public networks.

Fleet overview

Currently four aircraft (all E-4Bs) remain in service with the US Air Force. They are assigned to the 1st ACCS, 55th wing based at Offutt, Nebraska.

73-1676cn 20682, converted E-4A
73-1677cn 20683, converted E-4A
74-0787cn 20684, converted E-4A
75-0125cn 20949




The aircraft were originally based at Andrews AFB, Maryland. They were later moved to Offutt, where they would be safer from attack.




In 2006 the Secretary of Defense decided to phase out all E-4s starting 2009. In 2007 the new secretary reversed this decision keeping the fleet in service at least until 2020. Again this date was postponed, and the E-4 remains in service today. A successor is yet to be decided, which was also put on hold by the USAf in 2020. Some say the proposed E-10 (based on a Boeing 767 airframe) could replace the aging EC-135, E-8 and E-4s, although the E-10 program was cancelled.

For now, the E-4 remains the aerial command plane to support the commander in chief and key members of the battle staff.

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Gostar Den Daas
24 jul 2013 13:51
Interesting look inside! on cnet.