USAF Boeing E-4A Airborne Command Post

Additional Information:

The Boeing E-4 Advanced Airborne Command Post (AACP), the current “Nightwatch” aircraft, is a strategic command and control military aircraft operated by the United States Air Force (USAF). The E-4 series are specially modified from the Boeing 747-200B for the National Emergency Airborne Command Post (NEACP) program. The E-4 serves as a survivable mobile command post for the National Command Authority, namely the President of the United States, the Secretary of Defense, and successors. Two of the original 747-200 airframes were originally planned to be commercial airliners. When the airline did not complete the order, Boeing offered the airframes to the United States Air Force, as part of a package leading to a replacement for the older EC-135J National Emergency Airborne Command Post (NEACP). The Air Force Electronic Systems Division awarded Boeing a contract in February of 1973 for two unequipped aircraft, designated E-4A, powered by four P&W JT9D engines, to which a third aircraft was added in July of 1973.

By January of 1985, all three E-4As had been retrofitted to E-4B models and the E-4B offered a vast increase in communications capability over the previous model and was considered to be ‘hardened’ against the effects of a nuclear electromagnetic pulse (EMP) from a nuclear explosion. Hardening the aircraft meant that all equipment and wiring on board was shielded from an EMP. The E-4B is designed to survive an EMP with systems intact and has state-of-the-art direct fire countermeasures. Many older aircraft have been upgraded with glass cockpits. The E-4B still uses traditional analog flight instruments, as they are less susceptible to damage from an EMP blast.

The four E-4Bs are operated by the 1st Airborne Command and Control Squadron of the 595th Command and Control Group located at Offutt Air Force Base, near Omaha, Nebraska. An E-4B when in action is denoted a “National Airborne Operations Center” and has been nicknamed the “Doomsday plane”.

The E-4 fleet was originally deployed in 1974, when it was termed National Emergency Airborne Command Post (NEACP), often pronounced “kneecap”. The aircraft was to provide a survivable platform to conduct war operations in the event of a nuclear attack.

The Boeing E-4A aircraft was subjected to radiation exposure tests at Kirtland Air Force Base in Albuquerque New Mexico in October of 1973.

A Boeing E-4B, 50125 advanced airborne command post (AABNCP) on the nuclear electromagnetic pulse (EMP) simulator for testing at Kirtland AFB in this undated photo.

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