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Boeing E-4
The Boeing E-4 Advanced Airborne Command Post (AACP), the current "Nightwatch" aircraft, is a series of 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. The four E-4s 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-4 when in action is denoted a "National Airborne Operations Center" (NAOC) and has been nicknamed the "Doomsday plane".
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). Under the 481B NEACP program the Air Force Electronic Systems Division awarded Boeing a contract in February 1973 for two unequipped aircraft, designated E-4A, powered by four P&W JT9D engines, to which a third aircraft was added in July 1973.
In 1973, the first E-4A was completed at the Boeing plant in Everett, Washington. E-Systems won the contract to install interim equipment in these three aircraft. In July 1973, the first completed E-4A was delivered to Andrews Air Force Base, Maryland. The next two were delivered in October 1973 and October 1974.[citation needed] The third E-4A was powered by the GE F103 engine, which was later made standard and retrofitted to the previous two aircraft. The A-model effectively housed the same equipment as the EC-135, but offered more space and an ability to remain aloft longer than an EC-135.
In November 1973, it was reported that the program cost was estimated to total $548 million, equivalent to $3.88 billion in 2024 for seven 747s, with six as operational command posts and one more for research and development.
In December 1973, a fourth aircraft was ordered. It was fitted with more advanced equipment, resulting in the designation E-4B. On 21 December 1979, Boeing delivered the first E-4B, AF Serial Number 75-0125, which was distinguished from the earlier version by the presence of a large streamlined radome on the dorsal surface directly behind the upper deck. This contains the aircraft's SHF satellite antenna.
By January 1985, all three E-4As had been retrofitted to E-4B models. 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.
In 2005, the Air Force awarded Boeing a five-year, US$2 billion contract, equivalent to $3.22 billion in 2024, for the continued upgrade of the E-4B fleet. In addition to the purchase and upgrade costs, the E-4 costs nearly $160,000 per hour, equivalent to $209,628 in 2024, for the Air Force to operate. The E-4B fleet had an estimated unit cost of approximately US$223.2 million each in 2024.
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Boeing E-4
The Boeing E-4 Advanced Airborne Command Post (AACP), the current "Nightwatch" aircraft, is a series of 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. The four E-4s 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-4 when in action is denoted a "National Airborne Operations Center" (NAOC) and has been nicknamed the "Doomsday plane".
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). Under the 481B NEACP program the Air Force Electronic Systems Division awarded Boeing a contract in February 1973 for two unequipped aircraft, designated E-4A, powered by four P&W JT9D engines, to which a third aircraft was added in July 1973.
In 1973, the first E-4A was completed at the Boeing plant in Everett, Washington. E-Systems won the contract to install interim equipment in these three aircraft. In July 1973, the first completed E-4A was delivered to Andrews Air Force Base, Maryland. The next two were delivered in October 1973 and October 1974.[citation needed] The third E-4A was powered by the GE F103 engine, which was later made standard and retrofitted to the previous two aircraft. The A-model effectively housed the same equipment as the EC-135, but offered more space and an ability to remain aloft longer than an EC-135.
In November 1973, it was reported that the program cost was estimated to total $548 million, equivalent to $3.88 billion in 2024 for seven 747s, with six as operational command posts and one more for research and development.
In December 1973, a fourth aircraft was ordered. It was fitted with more advanced equipment, resulting in the designation E-4B. On 21 December 1979, Boeing delivered the first E-4B, AF Serial Number 75-0125, which was distinguished from the earlier version by the presence of a large streamlined radome on the dorsal surface directly behind the upper deck. This contains the aircraft's SHF satellite antenna.
By January 1985, all three E-4As had been retrofitted to E-4B models. 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.
In 2005, the Air Force awarded Boeing a five-year, US$2 billion contract, equivalent to $3.22 billion in 2024, for the continued upgrade of the E-4B fleet. In addition to the purchase and upgrade costs, the E-4 costs nearly $160,000 per hour, equivalent to $209,628 in 2024, for the Air Force to operate. The E-4B fleet had an estimated unit cost of approximately US$223.2 million each in 2024.