Boeing E-4 Nightwatch

The Boeing E-4 Advanced Airborne Command Post, with the project name "Nightwatch", is a strategic command and control military aircraft operated by the United States Air Force (USAF). The E-4 series was specially modified from the Boeing 747-200B. 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-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 is denoted a "National Airborne Operations Center" when in action.

Variants

 * E-4A: Three aircraft (s/n 73-1676, 73-1677, and 74-0787) produced, powered by Pratt & Whitney JT9D-7R4G2 engines. No bulge to house equipment on top of fuselage. These were later converted to E-4Bs.
 * E-4B: One built (s/n 75-0125) and equipped with 52,500-lb CF6-50E2 engines. Has nuclear electromagnetic pulse protection, nuclear and thermal effects shielding, advanced electronics, and a wide variety of communications equipment.

Users

 * United States
 * United States Air Force

Related Development

 * Boeing 747
 * Boeing VC-25
 * Boeing CC-180 Commander

Comparable Aircraft

 * Boeing E-6 Mercury
 * Bombardier CC-194V Galaxy Ambassador
 * Northrop Grumman E-10 MC2A