Spotting a particular type of aircraft in the sky could send chills down your spine. Known colloquially as the “Doomsday Plane,” the E-4B “Nightwatch” serves as a powerful symbol of the U.S. military’s readiness for nuclear disasters and extreme emergencies. Designed to act as a National Airborne Operations Center (NAOC), the E-4B ensures that crucial leadership, including the President and Secretary of Defense, remains in control even during catastrophic events. Here’s everything you need to know about the E-4B, why its presence is a cause for concern, and what its existence means for national security.