If you spot a specific type of aircraft looming in the sky, it might signal that humanity is on the brink of catastrophe. Known as the "Doomsday Plane ... isn't always a sign of disaster.

Following is the text of the video. This plane is an airborne version of the Pentagon. It's an E-4B nicknamed the Doomsday Plane. The military calls it "Nightwatch." It's designed to survive ...

One of these "survival system" elements was the development of "doomsday planes" or doomsday aircraft. "Doomsday planes" serve as airborne command centers. By taking to the air upon detecting the ...