Which indicator color signifies that the door is not armed?

The correct answer is green, indicating that the door is not armed. In aviation ground operations, the color coding for door status is essential for safety and ensuring proper procedures are followed. A green indicator typically signifies that the door is in a safe position, meaning it is not armed or ready for operation in the event of an emergency. This is crucial because when a door is armed, it can automatically deploy emergency slides in the event of an evacuation; thus, knowing its status—particularly that it is not armed—is vital for the safety of both crew and passengers.

In this context, the other colors—red, blue, and yellow—are associated with different states or warnings. For instance, a red indicator often signals danger or that the door is armed and ready. Knowing these color codes helps ground personnel quickly assess the condition of doors and take necessary actions during pre-flight checks and boarding processes.