Boeing E-4
（重定向自NEACP）
![White jet with blue cheatline in-flight over land, flying left. The aircraft features a distinctive bump above the usual 747's trademark nose profile](/Images/godic/202501/29/E_4b5652.jpg")
![A right front view of an E-4 advanced airborne command post (AABNCP) on the electromagnetic pulse (EMP) simulator for testing.](/Images/godic/202501/29/E-4_advanced_airborne_command_post_EMP_sim5652.jpg")
![National Emergency Airborne Command Post internal configuration, April 1976](/Images/godic/202501/29/BoeingE4AACPconfig5652.png")
![An E-4 at El Dorado International Airport in Bogotá, Colombia](/Images/godic/202501/29/Boeing_E-4B_in_Bogota5652.jpg")
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 55th Wing located at Offutt Air Force Base, near Omaha, Nebraska. An E-4B is denoted a "National Airborne Operations Center" when in action.