The US military's Boeing E-4B Nightwatch, also called the “Doomsday Plane,” made a rare public flight this week. It left Offutt Air Force Base, Nebraska on January 6 and flew to Camp Springs, Maryland, near Washington, DC, before landing at Los Angeles International Airport. Videos of the landing went viral because this plane usually stays out of sight. US media said Secretary of Defense Pete Hegseth was aboard. The Pentagon has not explained why the E-4B was used or the purpose of its flight. This secrecy adds to the plane’s mystery. The E-4B is a flying command post designed for extreme emergencies like nuclear war or attacks that destroy ground centers. It can protect against electromagnetic pulses, nuclear radiation, and maintains secure communications. The plane is crucial for the US Nuclear Command, Control and Communications system. The current E-4B fleet started with the E-4A from the late 1970s. The B-models arrived in the 1980s and all four in service are based at Offutt Air Force Base. One E-4B is always on alert. The plane can carry 111 people, including top military staff and communication experts. It costs over $223 million per plane (1998 dollars) and can fly 12 hours without refueling. Inside, the E-4B has command centers, briefing rooms, communications hubs, and can stay airborne longer with in-flight refueling. It provides continuous global links so leaders can work without ground support. The plane is managed by the US Strategic Command and Air Force. This plane has only been used once in a real crisis: after the 9/11 attacks. Training flights happen, but public sightings like this are rare. This flight occurred amid rising global tensions, including US military actions near Venezuela and the arrest of President Nicolás Maduro. Officials have not connected the E-4B flight to these events directly. However, the timing has raised speculation online. The E-4B is meant for times of uncertainty and high risk. When it is seen publicly, the big question is not what has happened, but what the US government is preparing for.