What nickname is given to the Boeing E-4B airborne command post?

The Boeing E-4B airborne command post is nicknamed Nightwatch.

The E-4B is a heavily modified Boeing 747-200 aircraft operated by the United States Air Force. It is designed to provide a survivable command, control, and communications center for senior national leaders during a major crisis. The aircraft can coordinate military forces if ground-based command facilities are damaged or unavailable.

The Nightwatch fleet was developed during the Cold War, when the possibility of a nuclear conflict made airborne command centers strategically important. Its equipment includes extensive communications systems, electromagnetic-pulse protection, and facilities for a large mission crew. The aircraft can also receive aerial refueling, allowing it to remain airborne for extended periods.

Nightwatch is sometimes confused with “Looking Glass,” the nickname of the U.S. Air Force’s EC-135 airborne command mission. It is also not the same aircraft as Air Force One, the presidential transport used for routine and emergency travel.