The Boeing E-4 Nightwatch, also known as the Advanced Airborne Command Post or the National Emergency Airborne Command Post (NEACP) is a modified Boeing 747-200B equipped, to be crude, to destroy the world. But the purpose of the aircraft, as destructive and apocalyptic as it may be, is actually defensive in nature. The E-4, known popularly as the “Doomsday plane”, was introduced in 1974 and has been keeping the United States “safe” ever since.
Originally destined to be airliners, the first two E-4s (73-1676 and 73-1677) were delivered in 1973 to replace the existing EC-135J NEACP. A third E-4 (74-0787) was ordered, purpose-built, and the first of the three was completed and delivered to Andrews Air Force Base in December 1974, designated E-4A. The following two aircraft were delivered in 1975. All three aircraft contained the same electronic equipment as the existing EC-135, but allowed for greater future expansion and longer loiter time. The original budgetary plans called for seven E-4s to be built, with one reserved for training and the remainder being used as command posts. However, soaring program costs saw only one more aircraft (75-0125) being ordered in 1973 and finally delivered six years later in 1979. The aircraft, a more advanced version of the E-4, was designated E-4B. Among the upgrades was increased hardening against the effects of an electromagnetic pulse (EMP); more advanced communications and electronic equipment were placed aboard, and the addition of extra radiation protection. Finally, an aerodynamic radome was added just behind the upper deck, giving the aircraft a distinct hump (the radome contains an SHF satellite antenna).
Cockpit of the E-4B Nightwatch. Note the largely analog instruments.
All E-4As were upgraded to E-4B status by January 1985. During the modification process, wire mesh similar to the mesh found on microwave oven doors was added to the cockpit windows to absorb radiation. The aircraft, built with a largely analog cockpit, has retained its outdated controls as opposed to being upgraded with a glass cockpit in order to better survive an EMP. While the longest known flight of an E-4B is 35 hours, the aircraft could actually remain airborne for much longer; the E-4B is equipped with an in-flight refueling system. The E-4B is equipped with various ways to communicate with land, air, and sea forces around the world, including a 5-mile wire antenna that can be trailed behind the aircraft (a Very Low Frequency communications system).
A command/control center on-board the E-4B. Note the overhead bins on the far-left, indicating this is one of the original two E-4s (converted airliners)
Since the end of the Cold War, the E-4B has been primarily used as the Secretary of Defense’s personal transport. Many of the systems have been continually updated, save of course for the cockpit. The aircraft can carry up to 112 crew members and is divided into three decks. The flight deck features a special navigation station that is not found on commercial models of the 747. Behind the flight deck is a lounge area and a bunk area for crew members. The middle-level deck has a secure conference room with a table for up to 9 people and a projection room with flat-screen TVs. Behind the projection room is an operations team area, which contains advanced computers, seating, and work areas for up to 29 staff members. The computers allow access to data processing systems, a switchboard, alternate phone and radio circuits, direct lines to various national capitols, and various other equipment. Walking aft from the operations team area takes you to the technical control area. This are acts as the central communications node for the aircraft. Various technicians communicate with the cockpit, ground stations, and satellites to maintain a constant stream of information between forces. Finally, the rear of the aircraft is a rest and sleeping areas for the remainder of the crew, along with food storage. A kitchen on board the aircraft keeps food flowing and bellies full, and in times of crisis that food is augmented with military-style MREs.
Cutaway drawing of the E-4A’s layout plans
Behind the forward entry area is the National Command Authority (NCA) room, an executive suite with an office, a lounge, a sleeping area, and a dressing room. The room is designed to provide the NCA with secure, reliable communication with US/allied forces globally. Behind the NCA area is a briefing room with a table that seats up to 21 people, a lectern, and two flat-screen TVs mounted to the wall. The communications control area is split between a data and a voice section. The voice section, on the starboard (right) side of the aircraft, has a radio operator’s console, a semi-automatic switchboard, and a communication officer’s console. The data area on the opposite side contains a record communication console, high-speed DATA/AUDIODIN/AFSAT console, a record data supervisor’s console, and the LF/VLF control heads. This enables the E-4B to communicate with anything on the spectrum between 14 kHz and 8.4 GHz. Finally, the lower portion of the aircraft contains the water supply tanks, electrical panels, VLF transmitter, SATCOM equipment, and other related pieces of machinery. There is also a trailing wire antenna (the 5-mile long reel) which can unrolled to communicate with Ohio-class ballistic missile submarines.
An E-4B being tested after EMP hardening
First deployed in 1974, the E-4, with all of its composite components, was designed to act as an airborne command post for the president and high-ranking government officials in times of major war or disaster. For these purposes, it has been used as a command/control platform after natural disasters, assisting local/FEMA personnel until ground-based command systems can be put in place. Originally stationed at Andrews AFB and later moved to their current home at Offutt AFB, the E-4 derives the name “Nightwatch” from the Rembrandt painting The Night Watch, which shows a scene of local citizens defending their township. The E-4’s utility faded with the acceptance of two modified Boeing 747-200Bs into USAF inventory, the VC-25As known to the public as Air Force One (technically any aircraft with the president aboard is Air Force One).
Secure phones aboard an E-4B
Today, one E-4B is kept on alert at all times. Crew members stay aboard the aircraft to guard it, and at the sound of a klaxon the aircraft is rapidly scrambled to safety. When the President travels aboard a VC-25A, an E-4B also accompanies the gaggle of aircraft that escort the president, ready to act as a backup should anything happen to incapacitate Air Force Once. Presently the Airborne Launch Control System (ALCS) aircraft, the one designed to order the launching of nuclear weapons in the event of a surprise attack that incapacitates the ground-based command authorities, is carried out by US Navy E-6B Mercury aircraft, which will be addressed in a later article.
